RCA Corp
RCA CorpActive Patents
0
Total Holdings
2385
Patent Holdings
Filter in Explorer →| Patent No. | Title | Status | Filing Date | Grant Date | Claims | Actions |
|---|---|---|---|---|---|---|
| GB1360470A | Computer input-output chaining system | Expired / Lapsed | 1971-12-03 | — | 0 | Details |
| GB1374122A | Electrical circuit providing bias voltages | Expired / Lapsed | 1971-09-22 | — | 0 | Details |
| DE1939594B2 | Identification card | Expired / Lapsed | 1969-08-04 | — | 0 | Details |
| GB1195775A | Electronic Editing Apparatus | Expired / Lapsed | 1968-03-28 | — | 0 | Details |
| GB1014986A | Apparatus for generating coherent radiation | Expired / Lapsed | 1964-01-01 | — | 0 | Details |
| US4710944A | Dual transmit-receive space diversity communication system | Expired / Lapsed | 1986-10-17 | 1987-12-01 | 13 | Details |
| US4708429A | Optical fiber assembly and optically coupled device package… | Expired / Lapsed | 1985-09-26 | 1987-11-24 | 33 | Details |
| US4706069A | Security system | Expired / Lapsed | 1986-04-08 | 1987-11-10 | 11 | Details |
| US4643186A | Percutaneous transluminal microwave catheter angioplasty | Expired / Lapsed | 1985-10-30 | 1987-02-17 | 12 | Details |
| US4639932A | Clock rate spread spectrum | Expired / Lapsed | 1985-08-29 | 1987-01-27 | 12 | Details |
| US4632127A | Scanning microwave hyperthermia with feedback temperature c… | Expired / Lapsed | 1985-06-17 | 1986-12-30 | 17 | Details |
| US4612618A | Hierarchical, computerized design of integrated circuits | Expired / Lapsed | 1983-06-10 | 1986-09-16 | 19 | Details |
| US4577316A | Synchronization system for a regenerative subtransponder sa… | Expired / Lapsed | 1984-02-13 | 1986-03-18 | 16 | Details |
| US4577215A | Dual word line, electrically alterable, nonvolatile floatin… | Expired / Lapsed | 1983-02-18 | 1986-03-18 | 6 | Details |
| US4575745A | Tailorable standard cells and method for tailoring the perf… | Expired / Lapsed | 1983-06-21 | 1986-03-11 | 5 | Details |
| US4570530A | Workpiece alignment system | Expired / Lapsed | 1983-12-14 | 1986-02-18 | 16 | Details |
| US4556265A | RF Coaxial-strip line connector | Expired / Lapsed | 1981-06-29 | 1985-12-03 | 7 | Details |
| US4504519A | Diamond-like film and process for producing same | Expired / Lapsed | 1983-11-03 | 1985-03-12 | 8 | Details |
| US4504946A | Time division multiple access communication systems | Expired / Lapsed | 1982-06-11 | 1985-03-12 | 11 | Details |
| US4485477A | Fast frequency/code search | Expired / Lapsed | 1982-07-19 | 1984-11-27 | 9 | Details |
| US4449563A | Counterbalance system for sagging rotating element | Expired / Lapsed | 1982-05-26 | 1984-05-22 | 13 | Details |
| US4442447A | Electrically alterable nonvolatile floating gate memory dev… | Expired / Lapsed | 1983-03-07 | 1984-04-10 | 7 | Details |
| US4435709A | Radar ranging system for use with sloping target | Expired / Lapsed | 1981-05-26 | 1984-03-06 | 15 | Details |
| US4363050A | Digitized audio record and playback system | Expired / Lapsed | 1980-07-28 | 1982-12-07 | 18 | Details |
| US4311154A | Nonsymmetrical bulb applicator for hyperthermic treatment o… | Expired / Lapsed | 1979-03-23 | 1982-01-19 | 8 | Details |
| US4292960A | Apparatus and method for application of radioactive and mic… | Expired / Lapsed | 1979-04-30 | 1981-10-06 | 14 | Details |
| US4283738A | NTSC to PAL transcoder | Expired / Lapsed | 1979-12-10 | 1981-08-11 | 12 | Details |
| US4282887A | Ridge-waveguide applicator for treatment with electromagnet… | Expired / Lapsed | 1979-10-11 | 1981-08-11 | 8 | Details |
| US4252848A | Perfluorinated polymer thin films | Expired / Lapsed | 1977-04-11 | 1981-02-24 | 8 | Details |
| US4249119A | Digital drive circuit for electric motor or the like | Expired / Lapsed | 1978-12-18 | 1981-02-03 | 11 | Details |
| US4239994A | Asymmetrically precharged sense amplifier | Expired / Lapsed | 1978-08-07 | 1980-12-16 | 18 | Details |
| US4228805A | Method of measuring blood perfusion | Expired / Lapsed | 1978-11-08 | 1980-10-21 | 5 | Details |
| US4225236A | Fabry-perot interferometer | Expired / Lapsed | 1977-11-11 | 1980-09-30 | 25 | Details |
| US4213096A | Phaselock receiver with phaselock detector | Expired / Lapsed | 1978-04-26 | 1980-07-15 | 6 | Details |
| US4204549A | Coaxial applicator for microwave hyperthermia | Expired / Lapsed | 1977-12-12 | 1980-05-27 | 11 | Details |
| US4204227A | Television picture compressor | Expired / Lapsed | 1977-12-19 | 1980-05-20 | 23 | Details |
| US4198246A | Pulsed laser irradiation for reducing resistivity of a dope… | Expired / Lapsed | 1978-11-27 | 1980-04-15 | 9 | Details |
| US4197921A | Anti-reflective acoustic wavefront refraction element | Expired / Lapsed | 1978-04-06 | 1980-04-15 | 14 | Details |
| US4197860A | Hyperthermia applicator | Expired / Lapsed | 1977-11-21 | 1980-04-15 | 5 | Details |
| US4181864A | Matching network for switchable segmented ultrasonic transd… | Expired / Lapsed | 1978-06-22 | 1980-01-01 | 4 | Details |
| US4168628A | Pulse-echo ultrasonic-imaging display system having time-va… | Expired / Lapsed | 1977-10-20 | 1979-09-25 | 6 | Details |
| US4168432A | Method of testing radiation hardness of a semiconductor dev… | Expired / Lapsed | 1978-01-16 | 1979-09-18 | 7 | Details |
| US4142209A | Disc track servo system | Expired / Lapsed | 1977-03-14 | 1979-02-27 | 5 | Details |
| US4138998A | Indicating temperature within living tissue | Expired / Lapsed | 1976-08-18 | 1979-02-13 | 6 | Details |
| US4114055A | Unbalanced sense circuit | Expired / Lapsed | 1977-05-12 | 1978-09-12 | 12 | Details |
| US4107680A | Digitally processed radar speed sensor | Expired / Lapsed | 1976-11-01 | 1978-08-15 | 7 | Details |
| US4085359A | Self-starting amplifier circuit | Expired / Lapsed | 1976-08-12 | 1978-04-18 | 6 | Details |
| US4063820A | Apparatus for measuring a dimension of an object | Expired / Lapsed | 1975-11-10 | 1977-12-20 | 4 | Details |
| US4037267A | Package for semiconductor components | Expired / Lapsed | 1976-05-24 | 1977-07-19 | 10 | Details |
| US4034373A | Airborne moving-target indicating radar system | Expired / Lapsed | 1973-11-08 | 1977-07-05 | 17 | Details |
| US4027192A | Electroluminescent device comprising electroluminescent lay… | Expired / Lapsed | 1975-07-18 | 1977-05-31 | 12 | Details |
| US4016564A | Multiple target data receiver for a collision avoidance sys… | Expired / Lapsed | 1975-12-22 | 1977-04-05 | 6 | Details |
| US4016550A | Charge transfer readout of charge injection device arrays | Expired / Lapsed | 1975-11-24 | 1977-04-05 | 31 | Details |
| US4013345A | Deformable mirror light valve and method of operating the s… | Expired / Lapsed | 1975-10-22 | 1977-03-22 | 10 | Details |
| US4003049A | Dual mode automobile collision avoidance radar | Expired / Lapsed | 1975-07-03 | 1977-01-11 | 8 | Details |
| US4003050A | Full range correlator for use in a collision avoidance syst… | Expired / Lapsed | 1975-04-21 | 1977-01-11 | 8 | Details |
| US3992676A | Current amplifiers | Expired / Lapsed | 1975-12-10 | 1976-11-16 | 17 | Details |
| US3984835A | Homodyne communication system | Expired / Lapsed | 1975-05-12 | 1976-10-05 | 22 | Details |
| US3979735A | Information storage circuit | Expired / Lapsed | 1975-03-10 | 1976-09-07 | 11 | Details |
| US3979611A | Transistor switching circuit | Expired / Lapsed | 1975-02-06 | 1976-09-07 | 10 | Details |
| US3978451A | Controlling communications between computer devices over co… | Expired / Lapsed | 1975-04-21 | 1976-08-31 | 5 | Details |
| US3974411A | Channel plate electron multiplier tube having reduced astig… | Expired / Lapsed | 1970-09-20 | 1976-08-10 | 6 | Details |
| US3973139A | Low power counting circuits | Expired / Lapsed | 1973-05-23 | 1976-08-03 | 13 | Details |
| US3960753A | Fluorescent liquid crystals | Expired / Lapsed | 1974-05-30 | 1976-06-01 | 6 | Details |
| US3956535A | Metal plated or platable article | Expired / Lapsed | 1974-01-30 | 1976-05-11 | 19 | Details |
| US3952586A | Determining engine compression from starter motor current | Expired / Lapsed | 1975-06-19 | 1976-04-27 | 12 | Details |
| US3931514A | Optical switching system | Expired / Lapsed | 1974-12-20 | 1976-01-06 | 17 | Details |
| US3918815A | Densitometer for measuring average aperture diameter | Expired / Lapsed | 1974-08-05 | 1975-11-11 | 17 | Details |
| US3912370A | Ac deformable mirror light valve | Expired / Lapsed | 1974-05-31 | 1975-10-14 | 8 | Details |
| US3883891A | Redundant signal processing error reduction technique | Expired / Lapsed | 1974-08-22 | 1975-05-13 | 11 | Details |
| US3882273A | Optical beam scanning system | Expired / Lapsed | 1973-10-24 | 1975-05-06 | 11 | Details |
| US3879710A | Data processor for a loop data communications system | Expired / Lapsed | 1974-03-01 | 1975-04-22 | 8 | Details |
| US3879582A | Data loop communication system | Expired / Lapsed | 1974-03-01 | 1975-04-22 | 11 | Details |
| US3877791A | Deformable mirror light valve and method of making the same | Expired / Lapsed | 1974-02-20 | 1975-04-15 | 4 | Details |
| US3876955A | Biasing circuit for differential amplifier | Expired / Lapsed | 1973-07-16 | 1975-04-08 | 8 | Details |
| US3868557A | Motion damping apparatus | Expired / Lapsed | 1972-10-13 | 1975-02-25 | 9 | Details |
| US3846696A | Current attenuator | Expired / Lapsed | 1973-07-20 | 1974-11-05 | 19 | Details |
| US3843843A | A time division multiple access synchronization technique | Expired / Lapsed | 1972-10-30 | 1974-10-22 | 10 | Details |
| US3840174A | Precision digital interpolator | Expired / Lapsed | 1973-05-29 | 1974-10-08 | 4 | Details |
| US3835253A | Television communication system with time delay compensation | Expired / Lapsed | 1972-07-10 | 1974-09-10 | 7 | Details |
| US3829853A | High-speed analog-to-digital converter | Expired / Lapsed | 1972-08-07 | 1974-08-13 | 2 | Details |
| US3816336A | Novel electro-optic devices | Expired / Lapsed | 1972-06-15 | 1974-06-11 | 5 | Details |
| US3806883A | Least recently used location indicator | Expired / Lapsed | 1972-11-22 | 1974-04-23 | 8 | Details |
| US3805117A | Hybrid electron device containing semiconductor chips | Expired / Lapsed | 1972-12-12 | 1974-04-16 | 5 | Details |
| US3803608A | Separation control of aircraft by non-synchronous techniques | Expired / Lapsed | 1970-04-10 | 1974-04-09 | 0 | Details |
| US3787715A | Control circuit employing digital techniques for loads such… | Expired / Lapsed | 1972-08-30 | 1974-01-22 | 12 | Details |
| US3787887A | Optical recorder with intensity control | Expired / Lapsed | 1971-04-29 | 1974-01-22 | 3 | Details |
| US3763480A | Digital and analog data handling devices | Expired / Lapsed | 1971-10-12 | 1973-10-02 | 29 | Details |
| US3755811A | Discriminating signaling system | Expired / Lapsed | 1968-06-10 | 1973-08-28 | 26 | Details |
| US3753774A | Method for making an intermetallic contact to a semiconduct… | Expired / Lapsed | 1971-04-05 | 1973-08-21 | 6 | Details |
| US3749658A | Method of fabricating transparent conductors | Expired / Lapsed | 1972-03-29 | 1973-07-31 | 0 | Details |
| US3750133A | Home television receiver modified to operate as video termi… | Expired / Lapsed | 1971-07-30 | 1973-07-31 | 11 | Details |
| US3739193A | Logic circuit | Expired / Lapsed | 1971-01-11 | 1973-06-12 | 5 | Details |
| US3735335A | Electronic fence vehicle locater transmitter and system usi… | Expired / Lapsed | 1971-12-20 | 1973-05-22 | 6 | Details |
| US3733430A | Channel monitoring system | Expired / Lapsed | 1970-12-28 | 1973-05-15 | 42 | Details |
| US3721955A | Disabled vehicle signalling system | Expired / Lapsed | 1971-07-15 | 1973-03-20 | 0 | Details |
| US3715485A | Radiation sensing and signal transfer circuits | Expired / Lapsed | 1971-10-12 | 1973-02-06 | 16 | Details |
| US3715477A | Video signal noise-limiting apparatus | Expired / Lapsed | 1971-03-11 | 1973-02-06 | 18 | Details |
| US3703331A | Liquid crystal display element having storage | Expired / Lapsed | 1971-11-26 | 1972-11-21 | 8 | Details |
| US3702990A | Variable threshold memory system using minimum amplitude si… | Expired / Lapsed | 1971-02-02 | 1972-11-14 | 12 | Details |
| US3701107A | Computer with probability means to transfer pages from larg… | Expired / Lapsed | 1970-10-01 | 1972-10-24 | 11 | Details |
| US3699533A | Memory system including buffer memories | Expired / Lapsed | 1970-10-29 | 1972-10-17 | 11 | Details |
| US3688025A | Recorder and playback apparatus for pulse width modulated r… | Expired / Lapsed | 1970-10-27 | 1972-08-29 | 18 | Details |
| US3683298A | Microwave apparatus using multiple avalanche diodes operati… | Expired / Lapsed | 1971-03-31 | 1972-08-08 | 8 | Details |
| US3683193A | Bucket brigade scanning of sensor array | Expired / Lapsed | 1970-10-26 | 1972-08-08 | 9 | Details |
| US3672925A | Method of preparing a substrate for depositing a metal on s… | Expired / Lapsed | 1970-10-02 | 1972-06-27 | 0 | Details |
| US3669673A | Recording of a continuous tone focused image on a diffracti… | Expired / Lapsed | 1970-10-23 | 1972-06-13 | 0 | Details |
| US3670153A | Machine implemented method for positioning and inspecting a… | Expired / Lapsed | 1970-10-08 | 1972-06-13 | 16 | Details |
| US3666359A | Correlation peak detector in optical spatial filtering syst… | Expired / Lapsed | 1970-08-26 | 1972-05-30 | 0 | Details |
| US3665256A | Heat dissipation for power integrated circuits | Expired / Lapsed | 1968-10-15 | 1972-05-23 | 4 | Details |
| US3660818A | Electro-optical memory | Expired / Lapsed | 1970-05-04 | 1972-05-02 | 11 | Details |
| US3653745A | Circuits for driving loads such as liquid crystal displays | Expired / Lapsed | 1970-06-11 | 1972-04-04 | 19 | Details |
| US3650603A | Liquid crystal light valve containing a mixture of nematic … | Expired / Lapsed | 1967-12-05 | 1972-03-21 | 11 | Details |
| US3648153A | Reference voltage source | Expired / Lapsed | 1970-11-04 | 1972-03-07 | 11 | Details |
| US3643019A | Variable length coding method and apparatus | Expired / Lapsed | 1970-04-22 | 1972-02-15 | 18 | Details |
| US3632436A | Contact system for semiconductor devices | Expired / Lapsed | 1969-07-11 | 1972-01-04 | 2 | Details |
| US3624634A | Color display | Expired / Lapsed | 1969-12-22 | 1971-11-30 | 17 | Details |
| US3617889A | Time-frequency-phase in-band coded communications system | Expired / Lapsed | 1969-08-13 | 1971-11-02 | 34 | Details |
| US3614767A | Electronic photocomposing system that forms characters of d… | Expired / Lapsed | 1968-12-24 | 1971-10-19 | 6 | Details |
| US3603962A | Color display for computer terminal | Expired / Lapsed | 1970-03-18 | 1971-09-07 | 7 | Details |
| US3599146A | Memory addressing failure detection | Expired / Lapsed | 1968-04-19 | 1971-08-10 | 2 | Details |
| US3588363A | Word recognition system for voice controller | Expired / Lapsed | 1969-07-30 | 1971-06-28 | 0 | Details |
| US3588353A | Speech synthesizer utilizing timewise truncation of adjacen… | Expired / Lapsed | 1968-02-26 | 1971-06-28 | 0 | Details |
| US3588439A | High resolution laser engraving apparatus | Expired / Lapsed | 1967-05-12 | 1971-06-28 | 0 | Details |
| US3587110A | Corporate-network printed antenna system | Expired / Lapsed | 1969-07-01 | 1971-06-22 | 5 | Details |
| US3577087A | Sequence {37 and{38 {0 gate with resetting means | Expired / Lapsed | 1968-09-27 | 1971-05-04 | 9 | Details |
| US3576542A | Priority circuit | Expired / Lapsed | 1968-03-08 | 1971-04-27 | 6 | Details |
| US3573785A | Stroboscopic display apparatus | Expired / Lapsed | 1967-10-23 | 1971-04-06 | 14 | Details |
| US3566357A | Multi-processor multi-programed computer system | Expired / Lapsed | 1966-07-05 | 1971-02-23 | 0 | Details |
| US3564131A | Spatially modulated halftone dot image generation system | Expired / Lapsed | 1967-12-22 | 1971-02-16 | 5 | Details |
| US3553676A | Electro-optical composition system | Expired / Lapsed | 1968-01-30 | 1971-01-05 | 0 | Details |
| US3546681A | Programmed method for manipulating electronic fonts in elec… | Expired / Lapsed | 1969-01-30 | 1970-12-08 | 0 | Details |
| US3542286A | Timing system for readout of stored data | Expired / Lapsed | 1967-10-06 | 1970-11-24 | 0 | Details |
| US3540361A | Optical field correction devices for an electronic photocom… | Expired / Lapsed | 1967-05-22 | 1970-11-17 | 0 | Details |
| US3540796A | Electro-optical compositions and devices | Expired / Lapsed | 1967-03-31 | 1970-11-17 | 0 | Details |
| US3535021A | Polarization controlled photochromic "write-in" system | Expired / Lapsed | 1968-05-13 | 1970-10-20 | 0 | Details |
| US3534245A | Electrical circuit for providing substantially constant cur… | Expired / Lapsed | 1967-12-08 | 1970-10-13 | 0 | Details |
| US3533088A | Control circuit for memory | Expired / Lapsed | 1967-10-31 | 1970-10-06 | 0 | Details |
| US3524077A | Translating information with multi-phase clock signals | Expired / Lapsed | 1968-02-28 | 1970-08-11 | 0 | Details |
| US3521198A | Electronically controlled delay line | Expired / Lapsed | 1965-08-09 | 1970-07-21 | 0 | Details |
| US3517792A | Multiple font keyboard | Expired / Lapsed | 1967-12-19 | 1970-06-30 | 0 | Details |
| US3515953A | Adaptive diode having mobile doping impurities | Expired / Lapsed | 1967-03-21 | 1970-06-02 | 0 | Details |
| US3505537A | Signal envelope discriminator and gating circuit | Expired / Lapsed | 1967-03-09 | 1970-04-07 | 0 | Details |
| US3500063A | Scanning laser obstruction detection system utilizing a ret… | Expired / Lapsed | 1968-06-10 | 1970-03-10 | 0 | Details |
| US3500411A | Retrodirective phased array antenna for a spacecraft | Expired / Lapsed | 1967-04-26 | 1970-03-10 | 0 | Details |
| US3499112A | Electro-optical device | Expired / Lapsed | 1967-03-31 | 1970-03-03 | 0 | Details |
| US3493812A | Integrated thin film translators | Expired / Lapsed | 1967-04-26 | 1970-02-03 | 0 | Details |
| US3493785A | Bistable circuits | Expired / Lapsed | 1966-03-24 | 1970-02-03 | 0 | Details |
| US3485237A | Self-propelling hose | Expired / Lapsed | 1967-03-20 | 1969-12-23 | 0 | Details |
| US3482243A | Protective system | Expired / Lapsed | 1966-10-28 | 1969-12-02 | 0 | Details |
| US3478213A | Photomultiplier or image amplifier with secondary emission … | Expired / Lapsed | 1967-09-05 | 1969-11-11 | 0 | Details |
| US3470540A | Multiprocessing computer system with special instruction se… | Expired / Lapsed | 1967-04-24 | 1969-09-30 | 0 | Details |
| US3466646A | Analog position to binary number translator | Expired / Lapsed | 1965-06-29 | 1969-09-09 | 0 | Details |
| US3465292A | Flexode crosspoint adaptive matrix circuits | Expired / Lapsed | 1965-10-29 | 1969-09-02 | 0 | Details |
| US3462742A | Computer system adapted to be constructed of large integrat… | Expired / Lapsed | 1966-12-21 | 1969-08-19 | 0 | Details |
| US3461361A | Complementary mos transistor integrated circuits with inver… | Expired / Lapsed | 1966-02-24 | 1969-08-12 | 0 | Details |
| US3460094A | Integrated memory system | Expired / Lapsed | 1967-01-16 | 1969-08-05 | 0 | Details |
| US3460043A | Priority circuits | Expired / Lapsed | 1966-04-06 | 1969-08-05 | 0 | Details |
| US3460120A | Random access card memory system | Expired / Lapsed | 1966-02-01 | 1969-08-05 | 0 | Details |
| US3457435A | Complementary field-effect transistor transmission gate | Expired / Lapsed | 1965-12-21 | 1969-07-22 | 0 | Details |
| US3455020A | Method of fabricating insulated-gate field-effect devices | Expired / Lapsed | 1966-10-13 | 1969-07-15 | 0 | Details |
| US3444319A | Character generator | Expired / Lapsed | 1966-07-26 | 1969-05-13 | 0 | Details |
| US3444316A | Beat frequency holograms | Expired / Lapsed | 1966-02-03 | 1969-05-13 | 0 | Details |
| US3443188A | Switching circuits | Expired / Lapsed | 1967-02-27 | 1969-05-06 | 0 | Details |
| US3441342A | Frequency and phase error detection means for synchronizati… | Expired / Lapsed | 1965-03-29 | 1969-04-29 | 0 | Details |
| US3440620A | Electro-optical memory | Expired / Lapsed | 1966-01-10 | 1969-04-22 | 2 | Details |
| US3440444A | Driver-sense circuit arrangement | Expired / Lapsed | 1965-12-30 | 1969-04-22 | 0 | Details |
| US3439317A | Coordinate converter system | Expired / Lapsed | 1967-12-20 | 1969-04-15 | 0 | Details |
| US3435138A | Solid state image pickup device utilizing insulated gate fi… | Expired / Lapsed | 1965-12-30 | 1969-03-25 | 0 | Details |
| US3429030A | Method of fabricating semiconductor devices | Expired / Lapsed | 1965-10-23 | 1969-02-25 | 0 | Details |
| US3427453A | System for switching the attitude reference of a satellite … | Expired / Lapsed | 1966-05-25 | 1969-02-11 | 0 | Details |
| US3426344A | Character generator for simultaneous display of separate ch… | Expired / Lapsed | 1966-03-23 | 1969-02-04 | 0 | Details |
| US3425001A | Dielectrically-loaded,parallel-plane microwave ferrite devi… | Expired / Lapsed | 1966-05-31 | 1969-01-28 | 0 | Details |
| US3422420A | Display systems | Expired / Lapsed | 1966-03-23 | 1969-01-14 | 0 | Details |
| US3413612A | Controlling interchanges between a computer and many commun… | Expired / Lapsed | 1966-03-18 | 1968-11-26 | 0 | Details |
| US3413448A | Information handling apparatus | Expired / Lapsed | 1961-05-25 | 1968-11-26 | 2 | Details |
| US3410203A | Non-impact printer employing laser beam and holographic ima… | Expired / Lapsed | 1967-02-01 | 1968-11-12 | 0 | Details |
| US3409878A | Controlling interchanges between a computer and many commun… | Expired / Lapsed | 1966-03-18 | 1968-11-05 | 0 | Details |
| US3396282A | Time delay circuit employing logic gate | Expired / Lapsed | 1965-08-20 | 1968-08-06 | 0 | Details |
| US3395398A | Means for servicing a plurality of data buffers | Expired / Lapsed | 1965-12-16 | 1968-07-30 | 0 | Details |
| US3387358A | Method of fabricating semiconductor device | Expired / Lapsed | 1966-11-07 | 1968-06-11 | 0 | Details |
| US3388292A | Insulated gate field-effect transistor means for informatio… | Expired / Lapsed | 1966-02-15 | 1968-06-11 | 0 | Details |
| US3388391A | Digital storage and generation of video signals | Expired / Lapsed | 1965-04-07 | 1968-06-11 | 0 | Details |
| US3378783A | Optimized digital amplifier utilizing insulated-gate field-… | Expired / Lapsed | 1965-12-13 | 1968-04-16 | 0 | Details |
| US3376478A | Voltage regulated power supply including ramp voltage start… | Expired / Lapsed | 1966-01-28 | 1968-04-02 | 0 | Details |
| US3373408A | Computer capable of switching between programs without stor… | Expired / Lapsed | 1965-04-16 | 1968-03-12 | 0 | Details |
| US3373418A | Bit buffering system | Expired / Lapsed | 1964-09-14 | 1968-03-12 | 0 | Details |
| US3370276A | Computer peripheral device control | Expired / Lapsed | 1965-05-05 | 1968-02-20 | 2 | Details |
| US3355636A | High power, high frequency transistor | Expired / Lapsed | 1965-06-29 | 1967-11-28 | 2 | Details |
| US3355637A | Insulated-gate field effect triode with an insulator having… | Expired / Lapsed | 1965-04-15 | 1967-11-28 | 2 | Details |
| US3355598A | Integrated logic arrays employing insulated-gate field-effe… | Expired / Lapsed | 1964-11-25 | 1967-11-28 | 1 | Details |
| US3355721A | Information storage | Expired / Lapsed | 1964-08-25 | 1967-11-28 | 2 | Details |
| US3350595A | Low dark current photoconductive device | Expired / Lapsed | 1965-11-15 | 1967-10-31 | 2 | Details |
| US3348209A | Buffer | Expired / Lapsed | 1964-11-27 | 1967-10-17 | 2 | Details |
| US3348064A | Flexible logic circuit utilizing field effect transistors a… | Expired / Lapsed | 1963-11-14 | 1967-10-17 | 2 | Details |
| US3345458A | Digital storage and generation of video signals | Expired / Lapsed | 1963-10-16 | 1967-10-03 | 2 | Details |
| US3341821A | Adaptive semiconductor device | Expired / Lapsed | 1964-10-30 | 1967-09-12 | 2 | Details |
| US3335224A | Signal distortion detection by sampling digital diphase sig… | Expired / Lapsed | 1963-06-21 | 1967-08-08 | 2 | Details |
| US3332137A | Method of isolating chips of a wafer of semiconductor mater… | Expired / Lapsed | 1964-09-28 | 1967-07-25 | 2 | Details |
| US3331125A | Semiconductor device fabrication | Expired / Lapsed | 1964-05-28 | 1967-07-18 | 2 | Details |
| US3331651A | Phased array light deflecting system | Expired / Lapsed | 1963-06-24 | 1967-07-18 | 2 | Details |
| US3327133A | Electronic switching | Expired / Lapsed | 1963-05-28 | 1967-06-20 | 2 | Details |
| US3323027A | Semiconductor devices with layer of silicon monoxide and ge… | Expired / Lapsed | 1964-09-16 | 1967-05-30 | 2 | Details |
| US3320013A | Selectively controllable light guide apparatus | Expired / Lapsed | 1963-06-03 | 1967-05-16 | 2 | Details |
| US3318993A | Interconnection of multi-layer circuits and method | Expired / Lapsed | 1963-07-11 | 1967-05-09 | 2 | Details |
| US3317315A | Electrostatic printing method and element | Expired / Lapsed | 1962-04-30 | 1967-05-02 | 4 | Details |
| US3312780A | Phase detector for comparing a fixed frequency and a variab… | Expired / Lapsed | 1965-02-23 | 1967-04-04 | 2 | Details |
| US3312950A | Buffer system with each channel transferring to a specified… | Expired / Lapsed | 1964-05-28 | 1967-04-04 | 2 | Details |
| US3312941A | Switching network | Expired / Lapsed | 1963-06-24 | 1967-04-04 | 2 | Details |
| US3310700A | Photoconductive device incorporating stabilizing layers on … | Expired / Lapsed | 1964-05-28 | 1967-03-21 | 2 | Details |
| US3310784A | Information processing apparatus | Expired / Lapsed | 1963-09-06 | 1967-03-21 | 2 | Details |
| US3303474A | Duplexing system for controlling online and standby conditi… | Expired / Lapsed | 1963-01-17 | 1967-02-07 | 2 | Details |
| US3301959A | Fm stereo high level demodulating system | Expired / Lapsed | 1964-01-15 | 1967-01-31 | 2 | Details |
| US3300832A | Method of making composite insulatorsemiconductor wafer | Expired / Lapsed | 1963-06-28 | 1967-01-31 | 2 | Details |
| US3302028A | High efficiency light modulation system | Expired / Lapsed | 1963-06-10 | 1967-01-31 | 2 | Details |
| US3293618A | Communications accumulation and distribution | Expired / Lapsed | 1963-10-04 | 1966-12-20 | 2 | Details |
| US3293604A | Character recognition system utilizing asynchronous zoning … | Expired / Lapsed | 1963-01-25 | 1966-12-20 | 2 | Details |
| US3290658A | Electronic computer with interrupt facility | Expired / Lapsed | 1963-12-11 | 1966-12-06 | 2 | Details |
| US3287705A | Computer system | Expired / Lapsed | 1963-03-07 | 1966-11-22 | 2 | Details |
| US3284782A | Memory storage system | Expired / Lapsed | 1966-02-16 | 1966-11-08 | 2 | Details |
| US3284663A | Display systems | Expired / Lapsed | 1963-05-17 | 1966-11-08 | 0 | Details |
| US3284722A | Light coupling device | Expired / Lapsed | 1963-03-22 | 1966-11-08 | 2 | Details |
| US3283180A | Logic circuits utilizing transistor as level shift means | Expired / Lapsed | 1963-03-22 | 1966-11-01 | 2 | Details |
| US3283306A | Information handling apparatus including time sharing of pl… | Expired / Lapsed | 1962-11-26 | 1966-11-01 | 2 | Details |
| US3274565A | Optical-photoconductive reproducer utilizing insulative liq… | Expired / Lapsed | 1961-05-01 | 1966-09-20 | 2 | Details |
| US3270291A | Laser control device using a saturable absorber | Expired / Lapsed | 1962-10-22 | 1966-08-30 | 2 | Details |
| US3267295A | Logic circuits | Expired / Lapsed | 1964-04-13 | 1966-08-16 | 2 | Details |
| US3267317A | Device for producing recombination radiation | Expired / Lapsed | 1963-02-25 | 1966-08-16 | 2 | Details |
| US3264567A | Binary coded decimal counter circuits | Expired / Lapsed | 1964-07-02 | 1966-08-02 | 2 | Details |
| US3264624A | System for the retrieval of information from a content addr… | Expired / Lapsed | 1962-07-30 | 1966-08-02 | 2 | Details |
| US3263030A | Digital crosspoint switch | Expired / Lapsed | 1961-09-26 | 1966-07-26 | 2 | Details |
| US3256443A | Laser multiplex communication system | Expired / Lapsed | 1962-11-27 | 1966-06-14 | 2 | Details |
| US3254241A | Symmetrical clipping circuit employing transistor saturatio… | Expired / Lapsed | 1962-10-01 | 1966-05-31 | 2 | Details |
| US3252009A | Pulse sequence generator | Expired / Lapsed | 1963-10-22 | 1966-05-17 | 2 | Details |
| US3249923A | Information handling apparatus | Expired / Lapsed | 1962-12-11 | 1966-05-03 | 2 | Details |
| US3248726A | Non-linear analog to digital converter | Expired / Lapsed | 1962-05-24 | 1966-04-26 | 2 | Details |
| US3246256A | Oscillator circuit with series connected negative resistanc… | Expired / Lapsed | 1964-06-08 | 1966-04-12 | 2 | Details |
| US3246173A | Signal translating circuit employing insulated-gate field e… | Expired / Lapsed | 1964-01-29 | 1966-04-12 | 2 | Details |
| US3246302A | Coupling of logic neurons | Expired / Lapsed | 1961-08-28 | 1966-04-12 | 1 | Details |
| US3245052A | Content addressed memory | Expired / Lapsed | 1962-05-17 | 1966-04-05 | 1 | Details |
| US3243628A | Electron multiplier with curved resistive secondary emissiv… | Expired / Lapsed | 1962-06-26 | 1966-03-29 | 2 | Details |
| US3242433A | Uhf adaptor for vhf television receivers | Expired / Lapsed | 1962-08-13 | 1966-03-22 | 2 | Details |
| US3241114A | Comparator systems | Expired / Lapsed | 1962-11-27 | 1966-03-15 | 2 | Details |
| US3237176A | Binary recording system | Expired / Lapsed | 1962-01-26 | 1966-02-22 | 2 | Details |
| US3234401A | Storage circuits | Expired / Lapsed | 1962-02-05 | 1966-02-08 | 2 | Details |
| US3234332A | Acoustic apparatus and method for analyzing speech | Expired / Lapsed | 1961-12-01 | 1966-02-08 | 1 | Details |
| US3234521A | Data processing system | Expired / Lapsed | 1961-08-08 | 1966-02-08 | 2 | Details |
| US3233123A | Integrated insulated-gate field-effect transistor circuit o… | Expired / Lapsed | 1963-02-14 | 1966-02-01 | 2 | Details |
| US3229218A | Field-effect transistor circuit | Expired / Lapsed | 1963-03-07 | 1966-01-11 | 1 | Details |
| US3229223A | Laser modulation system having internal polarization vector… | Expired / Lapsed | 1962-09-10 | 1966-01-11 | 2 | Details |
| US3221302A | Transducer position control apparatus | Expired / Lapsed | 1961-05-15 | 1965-11-30 | 2 | Details |
| US3218618A | Magnetic reading apparatus for demodulating a recorded freq… | Expired / Lapsed | 1962-01-30 | 1965-11-16 | 1 | Details |
| US3217181A | Logic switching circuit comprising a plurality of discrete … | Expired / Lapsed | 1962-09-11 | 1965-11-09 | 2 | Details |
| US3215861A | Binary inverter circuit employing field effect transistors | Expired / Lapsed | 1962-11-28 | 1965-11-02 | 1 | Details |
| US3213299A | Linearized field-effect transistor circuit | Expired / Lapsed | 1963-05-20 | 1965-10-19 | 2 | Details |
| US3211832A | Processing apparatus utilizing simulated neurons | Expired / Lapsed | 1961-08-28 | 1965-10-12 | 2 | Details |
| US3202840A | Frequency doubler employing two push-pull pulsed internal f… | Expired / Lapsed | 1963-03-19 | 1965-08-24 | 2 | Details |
| US3201574A | Flexible logic circuit | Expired / Lapsed | 1960-10-07 | 1965-08-17 | 1 | Details |
| US3200240A | Perforated record member sensing apparatus | Expired / Lapsed | 1960-12-07 | 1965-08-10 | 0 | Details |
| US3197742A | Search apparatus | Expired / Lapsed | 1960-01-11 | 1965-07-27 | 2 | Details |
| US3193770A | Voltage and phase memory system | Expired / Lapsed | 1961-05-03 | 1965-07-06 | 2 | Details |
| US3191061A | Insulated gate field effect devices and electrical circuits… | Expired / Lapsed | 1962-05-31 | 1965-06-22 | 2 | Details |
| US3188251A | Method for making semiconductor junction devices | Expired / Lapsed | 1962-01-19 | 1965-06-08 | 2 | Details |
| US3179542A | Method of making semiconductor devices | Expired / Lapsed | 1961-10-24 | 1965-04-20 | 1 | Details |
| US3179854A | Modular structures and methods of making them | Expired / Lapsed | 1961-04-24 | 1965-04-20 | 2 | Details |
| US3177100A | Depositing epitaxial layer of silicon from a vapor mixture … | Expired / Lapsed | 1963-09-09 | 1965-04-06 | 2 | Details |
| US3177433A | Means for modifying the waveform of a pulse as it passes th… | Expired / Lapsed | 1961-08-15 | 1965-04-06 | 2 | Details |
| US3175198A | Superconductor films | Expired / Lapsed | 1962-10-02 | 1965-03-23 | 2 | Details |
| US3171100A | Punchable memory card having printed circuit thereon | Expired / Lapsed | 1962-03-21 | 1965-02-23 | 2 | Details |
| US3160766A | Switching circuit with a capacitor directly connected betwe… | Expired / Lapsed | 1962-11-28 | 1964-12-08 | 2 | Details |
| US3140464A | Central parity checker operating from and into a data trans… | Expired / Lapsed | 1961-05-31 | 1964-07-07 | 2 | Details |
| US3135913A | Apparatus for testing tubes for all possible short circuits… | Expired / Lapsed | 1959-12-30 | 1964-06-02 | 2 | Details |
| US3131312A | Circuit for linearizing resistance of a field-effect transi… | Expired / Lapsed | 1960-08-05 | 1964-04-28 | 2 | Details |
| US3130371A | Pulse amplitude slicing circuit | Expired / Lapsed | 1959-08-26 | 1964-04-21 | 2 | Details |
| US3122649A | Tunnel diode flip-flop with tunnel rectifier cross-coupling | Expired / Lapsed | 1960-09-20 | 1964-02-25 | 2 | Details |
| US3122647A | Pulse length discriminator utilizing two gating circuits | Expired / Lapsed | 1960-08-29 | 1964-02-25 | 2 | Details |
| FR1350949A | Control arrangement for simultaneously activating current o… | Expired / Lapsed | 1963-01-25 | 1964-01-31 | 0 | Details |
| US3119935A | Network employing reset means for bistable operating gating… | Expired / Lapsed | 1959-11-27 | 1964-01-28 | 2 | Details |
| US3118055A | Electronic digital information handling system with charact… | Expired / Lapsed | 1954-12-28 | 1964-01-14 | 2 | Details |
| US3115076A | Communication printer | Expired / Lapsed | 1961-10-30 | 1963-12-24 | 2 | Details |
| US3115585A | Logic circuit with inductive self-resetting of negative res… | Expired / Lapsed | 1961-03-08 | 1963-12-24 | 2 | Details |
| US3114882A | Thyristor receiver | Expired / Lapsed | 1960-11-01 | 1963-12-17 | 2 | Details |
| US3114663A | Method of providing semiconductor wafers with protective an… | Expired / Lapsed | 1960-03-29 | 1963-12-17 | 1 | Details |
| US3113206A | Binary adder | Expired / Lapsed | 1960-10-17 | 1963-12-03 | 2 | Details |
| US3107277A | Electrical devices | Expired / Lapsed | 1960-07-05 | 1963-10-15 | 1 | Details |
| US3100838A | Binary full adder utilizing integrated unipolar transistors | Expired / Lapsed | 1960-06-22 | 1963-08-13 | 2 | Details |
| US3097308A | Semiconductor device with surface electrode producing elect… | Expired / Lapsed | 1959-03-09 | 1963-07-09 | 2 | Details |
| US3092998A | Thermometers | Expired / Lapsed | 1960-08-08 | 1963-06-11 | 1 | Details |
| US3091392A | Binary magnitude comparator | Expired / Lapsed | 1960-06-20 | 1963-05-28 | 2 | Details |
| US3090956A | Steerable antenna | Expired / Lapsed | 1960-12-23 | 1963-05-21 | 2 | Details |
| US3088668A | Binary adder employing minority logic | Expired / Lapsed | 1960-09-14 | 1963-05-07 | 2 | Details |
| US3076339A | Thermometer | Expired / Lapsed | 1960-04-07 | 1963-02-05 | 1 | Details |
| US3076181A | Shifting apparatus | Expired / Lapsed | 1957-09-26 | 1963-01-29 | 2 | Details |
| US3075189A | Radar | Expired / Lapsed | 1958-09-08 | 1963-01-22 | 2 | Details |
| US3070711A | Shift register | Expired / Lapsed | 1958-12-16 | 1962-12-25 | 0 | Details |
| US3068338A | Thermostatically controlled circuits | Expired / Lapsed | 1960-12-22 | 1962-12-11 | 0 | Details |
| US3068405A | Pulse circuits | Expired / Lapsed | 1959-06-19 | 1962-12-11 | 0 | Details |
| US3068465A | High resolution recording and display | Expired / Lapsed | 1957-06-06 | 1962-12-11 | 0 | Details |
| US3060422A | Indicator and/or control system | Expired / Lapsed | 1941-11-29 | 1962-10-23 | 0 | Details |
| US3054958A | Pulse generating system | Expired / Lapsed | 1956-10-12 | 1962-09-18 | 0 | Details |
| US3054034A | Semiconductor devices and method of manufacture thereof | Expired / Lapsed | 1958-10-01 | 1962-09-11 | 0 | Details |
| US3050637A | Tunnel diode driver | Expired / Lapsed | 1961-01-05 | 1962-08-21 | 0 | Details |
| US3050700A | Phase shifting circuit | Expired / Lapsed | 1959-01-19 | 1962-08-21 | 0 | Details |
| US3048717A | Peak time detecting circuit | Expired / Lapsed | 1960-12-16 | 1962-08-07 | 0 | Details |
| US3048797A | Semiconductor modulator | Expired / Lapsed | 1957-04-30 | 1962-08-07 | 0 | Details |
| US3047843A | Monitoring circuits | Expired / Lapsed | 1957-02-15 | 1962-07-31 | 0 | Details |
| US3046176A | Fabricating semiconductor devices | Expired / Lapsed | 1958-07-25 | 1962-07-24 | 2 | Details |
| US3038085A | Shift-register utilizing unitary multielectrode semiconduct… | Expired / Lapsed | 1958-03-25 | 1962-06-05 | 0 | Details |
| US3037093A | Magnetic recording and reproducing apparatus | Expired / Lapsed | 1959-09-29 | 1962-05-29 | 0 | Details |
| US3037090A | System for duplicating magnetic tape records | Expired / Lapsed | 1957-01-25 | 1962-05-29 | 0 | Details |
| US3034356A | Balanced pressure transducers | Expired / Lapsed | 1958-05-06 | 1962-05-15 | 0 | Details |
| US3028500A | Photoelectric apparatus | Expired / Lapsed | 1956-08-24 | 1962-04-03 | 0 | Details |
| US3018391A | Semiconductor signal converter apparatus | Expired / Lapsed | 1959-04-29 | 1962-01-23 | 0 | Details |
| US3018389A | Delay circuit using magnetic cores and transistor storage d… | Expired / Lapsed | 1958-06-03 | 1962-01-23 | 0 | Details |
| US3018369A | Transistorized direction finder receiver having a local aud… | Expired / Lapsed | 1958-03-12 | 1962-01-23 | 0 | Details |
| CA634051A | Memory systems | Expired / Lapsed | — | 1962-01-02 | 0 | Details |
| US3009111A | Signal translating system | Expired / Lapsed | 1957-01-02 | 1961-11-14 | 0 | Details |
| US3008129A | Memory systems | Expired / Lapsed | 1956-07-18 | 1961-11-07 | 0 | Details |
| US3007137A | Information handling system | Expired / Lapsed | 1956-12-14 | 1961-10-31 | 0 | Details |
| US3005937A | Semiconductor signal translating devices | Expired / Lapsed | 1958-08-21 | 1961-10-24 | 0 | Details |
| US3002123A | Traveling wave tube structure | Expired / Lapsed | 1957-01-11 | 1961-09-26 | 0 | Details |
| US2992356A | Traveling wave amplifier tube | Expired / Lapsed | 1956-07-31 | 1961-07-11 | 0 | Details |
| US2991469A | Radar test set | Expired / Lapsed | 1955-10-31 | 1961-07-04 | 0 | Details |
| US2985805A | Semiconductor devices | Expired / Lapsed | 1958-03-05 | 1961-05-23 | 0 | Details |
| US2980808A | Switching circuit comprising temperature controlled semicon… | Expired / Lapsed | 1957-11-20 | 1961-04-18 | 0 | Details |
| US2975291A | Electroluminescent storage device | Expired / Lapsed | 1957-10-17 | 1961-03-14 | 0 | Details |
| US2975299A | Time discriminator | Expired / Lapsed | 1957-01-02 | 1961-03-14 | 0 | Details |
| US2975231A | Delayed action color killer and automatic chroma control ci… | Expired / Lapsed | 1956-06-01 | 1961-03-14 | 0 | Details |
| US2974236A | Multi-electrode semiconductor devices | Expired / Lapsed | 1953-03-11 | 1961-03-07 | 0 | Details |
| US2972092A | Semiconductor devices | Expired / Lapsed | 1959-08-11 | 1961-02-14 | 0 | Details |
| US2967988A | Battery charging system | Expired / Lapsed | 1958-03-25 | 1961-01-10 | 0 | Details |
| US2967344A | Semiconductor devices | Expired / Lapsed | 1958-02-14 | 1961-01-10 | 0 | Details |
| US2967991A | Power supply | Expired / Lapsed | 1957-01-08 | 1961-01-10 | 0 | Details |
| US2967248A | Electroluminescent device | Expired / Lapsed | 1956-09-06 | 1961-01-03 | 0 | Details |
| US2965898A | Antenna | Expired / Lapsed | 1958-05-26 | 1960-12-20 | 0 | Details |
| US2965770A | Linear wave generator | Expired / Lapsed | 1957-03-29 | 1960-12-20 | 0 | Details |
| US2962639A | Semiconductor devices and mounting means therefor | Expired / Lapsed | 1955-07-25 | 1960-11-29 | 0 | Details |
| US2961643A | Information handling system | Expired / Lapsed | 1954-07-01 | 1960-11-22 | 0 | Details |
| US2957941A | System for narrow-band transmission of pictorial information | Expired / Lapsed | 1954-10-01 | 1960-10-25 | 0 | Details |
| US2953529A | Semiconductive radiation-sensitive device | Expired / Lapsed | 1957-04-01 | 1960-09-20 | 2 | Details |
| US2951234A | Storage interrogation system | Expired / Lapsed | 1956-10-31 | 1960-08-30 | 0 | Details |
| US2948884A | Gating pulse generator | Expired / Lapsed | 1956-06-01 | 1960-08-09 | 0 | Details |
| US2944202A | Multi-phase servo system | Expired / Lapsed | 1959-01-22 | 1960-07-05 | 0 | Details |
| US2942229A | Multiple contact connector | Expired / Lapsed | 1956-01-31 | 1960-06-21 | 0 | Details |
| US2941188A | Printer control system | Expired / Lapsed | 1954-07-01 | 1960-06-14 | 0 | Details |
| US2939332A | Mechanical movement | Expired / Lapsed | 1955-05-31 | 1960-06-07 | 0 | Details |
| US2940006A | Magnetron-traveling wave tube amplifier | Expired / Lapsed | 1954-10-22 | 1960-06-07 | 0 | Details |
| US2935732A | Sorting apparatus | Expired / Lapsed | 1954-05-03 | 1960-05-03 | 0 | Details |
| US2933720A | Magnetic memory systems | Expired / Lapsed | 1956-12-31 | 1960-04-19 | 0 | Details |
| US2933254A | Computing device | Expired / Lapsed | 1954-05-03 | 1960-04-19 | 0 | Details |
| US2929859A | Semiconductor devices | Expired / Lapsed | 1957-03-12 | 1960-03-22 | 1 | Details |
| US2929885A | Semiconductor transducers | Expired / Lapsed | 1953-05-20 | 1960-03-22 | 0 | Details |
| US2928667A | Gravitational or accelerational responsive device | Expired / Lapsed | 1953-08-24 | 1960-03-15 | 0 | Details |
| US2926284A | Sawtooth wave generator | Expired / Lapsed | 1957-02-25 | 1960-02-23 | 0 | Details |
| US2925588A | Memory reading system | Expired / Lapsed | 1954-12-31 | 1960-02-16 | 0 | Details |
| US2925220A | Function generator | Expired / Lapsed | 1954-09-30 | 1960-02-16 | 0 | Details |
| US2922142A | Remote control system | Expired / Lapsed | 1957-05-29 | 1960-01-19 | 0 | Details |
| US2921231A | Television deflection circuits | Expired / Lapsed | 1958-03-24 | 1960-01-12 | 0 | Details |
| US2921121A | Notch filter in brightness channel of color television tran… | Expired / Lapsed | 1955-04-01 | 1960-01-12 | 0 | Details |
| US2921128A | Picture signal compensation by change of beam size | Expired / Lapsed | 1955-02-01 | 1960-01-12 | 0 | Details |
| US2920215A | Switching circuit | Expired / Lapsed | 1956-10-31 | 1960-01-05 | 0 | Details |
| US2918600A | Storage tube | Expired / Lapsed | 1957-07-29 | 1959-12-22 | 0 | Details |
| US2918216A | Particle counting apparatus | Expired / Lapsed | 1956-08-31 | 1959-12-22 | 0 | Details |
| US2915812A | Method of constructing magnetic heads | Expired / Lapsed | 1956-03-09 | 1959-12-08 | 0 | Details |
| US2915582A | Dynamic control circuit for cathode ray tubes | Expired / Lapsed | 1956-03-27 | 1959-12-01 | 0 | Details |
| US2914403A | Electrostatic printing | Expired / Lapsed | 1955-05-17 | 1959-11-24 | 2 | Details |
| US2913676A | Semiconductor devices and systems | Expired / Lapsed | 1955-04-18 | 1959-11-17 | 0 | Details |
| US2912574A | Power saving and decoding circuit for radio receiver | Expired / Lapsed | 1957-08-19 | 1959-11-10 | 0 | Details |
| US2911631A | Magnetic memory systems | Expired / Lapsed | 1958-06-27 | 1959-11-03 | 0 | Details |
| US2911628A | Magnetic systems | Expired / Lapsed | 1957-05-01 | 1959-11-03 | 0 | Details |
| US2911622A | Serial memory | Expired / Lapsed | 1954-07-01 | 1959-11-03 | 0 | Details |
| US2911621A | Bidirectional static magnetic storage | Expired / Lapsed | 1952-06-02 | 1959-11-03 | 0 | Details |
| US2908835A | Pickup tube and target therefor | Expired / Lapsed | 1954-10-04 | 1959-10-13 | 0 | Details |
| US2906200A | Indexing device | Expired / Lapsed | 1957-03-14 | 1959-09-29 | 0 | Details |
| US2907021A | Digital-to-analogue converter | Expired / Lapsed | 1956-12-31 | 1959-09-29 | 0 | Details |
| US2907001A | Information handling systems | Expired / Lapsed | 1956-12-31 | 1959-09-29 | 0 | Details |
| US2907010A | System to control inter-message spacing | Expired / Lapsed | 1956-07-30 | 1959-09-29 | 0 | Details |
| US2907004A | Serial memory | Expired / Lapsed | 1954-10-29 | 1959-09-29 | 0 | Details |
| US2907005A | Serial memory | Expired / Lapsed | 1954-10-29 | 1959-09-29 | 0 | Details |
| US2907003A | Information handling system | Expired / Lapsed | 1954-07-01 | 1959-09-29 | 0 | Details |
| US2907002A | Message spacing control system | Expired / Lapsed | 1954-03-29 | 1959-09-29 | 0 | Details |
| US2905836A | Semiconductor devices and systems | Expired / Lapsed | 1955-07-27 | 1959-09-22 | 0 | Details |
| US2904781A | Monitoring circuits | Expired / Lapsed | 1957-02-15 | 1959-09-15 | 0 | Details |
| US2904626A | Electrical display device | Expired / Lapsed | 1955-05-31 | 1959-09-15 | 0 | Details |
| US2903513A | Storage and switching apparatus for automatic telegraph sig… | Expired / Lapsed | 1953-09-14 | 1959-09-08 | 0 | Details |
| US2901639A | Semi-conductor multivibrator circuit | Expired / Lapsed | 1954-12-31 | 1959-08-25 | 0 | Details |
| US2900531A | Field-effect transistor | Expired / Lapsed | 1957-02-28 | 1959-08-18 | 0 | Details |
| US2898509A | Static magnetic field means for color television receivers | Expired / Lapsed | 1958-06-26 | 1959-08-04 | 0 | Details |
| US2898455A | Diversity receiver having individually controlled channel t… | Expired / Lapsed | 1957-10-30 | 1959-08-04 | 0 | Details |
| US2898399A | Color television receivers | Expired / Lapsed | 1954-09-14 | 1959-08-04 | 0 | Details |
| US2897377A | Semiconductor surface treatments and devices made thereby | Expired / Lapsed | 1955-06-20 | 1959-07-28 | 0 | Details |
| US2896114A | Television deflection and power supply circuits | Expired / Lapsed | 1957-04-18 | 1959-07-21 | 0 | Details |
| US2894684A | Parity generator | Expired / Lapsed | 1956-09-28 | 1959-07-14 | 0 | Details |
| US2895127A | Directive diplex antenna | Expired / Lapsed | 1954-07-20 | 1959-07-14 | 0 | Details |
| US2895004A | Color television | Expired / Lapsed | 1954-04-28 | 1959-07-14 | 0 | Details |
| US2892165A | Temperature stabilized two-terminal semi-conductor filter c… | Expired / Lapsed | 1954-10-27 | 1959-06-23 | 0 | Details |
| US2890352A | Amplitude discriminatory system | Expired / Lapsed | 1953-08-24 | 1959-06-09 | 0 | Details |
| US2888562A | Frequency control system | Expired / Lapsed | 1956-05-10 | 1959-05-26 | 0 | Details |
| US2885659A | Electronic library system | Expired / Lapsed | 1954-09-22 | 1959-05-05 | 0 | Details |
| US2885495A | Emitter coupled transistor amplifier | Expired / Lapsed | 1954-03-24 | 1959-05-05 | 0 | Details |
| US2885488A | Magnetic record transducer | Expired / Lapsed | 1952-09-30 | 1959-05-05 | 0 | Details |
| US2885665A | Pulse echo recognition systems | Expired / Lapsed | 1941-05-29 | 1959-05-05 | 0 | Details |
| US2884587A | Variable voltage switching device | Expired / Lapsed | 1957-06-26 | 1959-04-28 | 0 | Details |
| US2884622A | Magnetic switching systems | Expired / Lapsed | 1956-06-27 | 1959-04-28 | 0 | Details |
| US2884616A | Multiple character comparator | Expired / Lapsed | 1954-04-30 | 1959-04-28 | 0 | Details |
| US2883638A | Pneumatic electrical connector | Expired / Lapsed | 1957-08-22 | 1959-04-21 | 0 | Details |
| US2883313A | Semiconductor devices | Expired / Lapsed | 1954-08-16 | 1959-04-21 | 2 | Details |
| US2881255A | Magnetic recording system | Expired / Lapsed | 1954-10-25 | 1959-04-07 | 0 | Details |
| US2881388A | Television test signal generator and method of use | Expired / Lapsed | 1954-07-01 | 1959-04-07 | 0 | Details |
| US2880268A | Light filter | Expired / Lapsed | 1954-11-10 | 1959-03-31 | 0 | Details |
| US2878380A | Push-pull signal amplifier | Expired / Lapsed | 1956-11-30 | 1959-03-17 | 0 | Details |
| US2878298A | Ignition system | Expired / Lapsed | 1953-12-30 | 1959-03-17 | 0 | Details |
| US2877446A | Information handling device | Expired / Lapsed | 1954-12-28 | 1959-03-10 | 0 | Details |
| US2877284A | Photovoltaic apparatus | Expired / Lapsed | 1950-05-23 | 1959-03-10 | 2 | Details |
| US2876349A | Signal processing circuits | Expired / Lapsed | 1954-07-30 | 1959-03-03 | 0 | Details |
| US2874278A | Tuning mechanism | Expired / Lapsed | 1956-10-23 | 1959-02-17 | 0 | Details |
| US2874213A | Multiplex transmission | Expired / Lapsed | 1954-06-29 | 1959-02-17 | 0 | Details |
| US2873367A | Angle modulation detector | Expired / Lapsed | 1953-11-19 | 1959-02-10 | 0 | Details |
| US2870050A | Semiconductor devices and methods of making same | Expired / Lapsed | 1957-06-25 | 1959-01-20 | 2 | Details |
| US2866857A | Phonograph pickup | Expired / Lapsed | 1955-12-20 | 1958-12-30 | 0 | Details |
| US2866858A | Wide band signal amplifier circuit | Expired / Lapsed | 1954-11-08 | 1958-12-30 | 0 | Details |
| US2864961A | Transistor electronic switch | Expired / Lapsed | 1954-09-03 | 1958-12-16 | 0 | Details |
| US2863069A | Transistor sweep circuit | Expired / Lapsed | 1954-11-26 | 1958-12-02 | 0 | Details |
| US2863123A | Transistor control circuit | Expired / Lapsed | 1954-11-08 | 1958-12-02 | 0 | Details |
| US2863056A | Semiconductor devices | Expired / Lapsed | 1954-02-01 | 1958-12-02 | 0 | Details |
| US2861909A | Semiconductor devices | Expired / Lapsed | 1955-04-25 | 1958-11-25 | 2 | Details |
| US2861262A | Photoelectric coding device | Expired / Lapsed | 1955-08-23 | 1958-11-18 | 0 | Details |
| US2860196A | Transistor amplifier with overload protection | Expired / Lapsed | 1956-07-02 | 1958-11-11 | 0 | Details |
| US2860193A | Stabilized transistor amplifier | Expired / Lapsed | 1954-04-01 | 1958-11-11 | 0 | Details |
| US2858531A | Radar systems | Expired / Lapsed | 1955-12-16 | 1958-10-28 | 0 | Details |
| US2858379A | High input impedance transistor amplifier circuits | Expired / Lapsed | 1954-10-01 | 1958-10-28 | 0 | Details |
| US2858363A | Electroluminescent image reproduction | Expired / Lapsed | 1952-10-20 | 1958-10-28 | 0 | Details |
| US2857462A | Transistor amplifier circuit | Expired / Lapsed | 1956-07-12 | 1958-10-21 | 0 | Details |
| US2857455A | Subscription color television system | Expired / Lapsed | 1953-12-01 | 1958-10-21 | 0 | Details |
| US2857573A | Frequency modulated transistor oscillator | Expired / Lapsed | 1953-05-22 | 1958-10-21 | 0 | Details |
| US2856589A | Light-controlled waveguide attenuator | Expired / Lapsed | 1954-04-20 | 1958-10-14 | 0 | Details |
| US2854652A | Information selecting circuit | Expired / Lapsed | 1954-03-25 | 1958-09-30 | 0 | Details |
| US2853698A | Compression system | Expired / Lapsed | 1955-09-23 | 1958-09-23 | 0 | Details |
| US2853693A | Switching devices | Expired / Lapsed | 1950-12-28 | 1958-09-23 | 0 | Details |
| US2851592A | Carrier wave powered radio transceiver circuits | Expired / Lapsed | 1952-12-03 | 1958-09-09 | 0 | Details |
| US2848607A | Information handling system | Expired / Lapsed | 1954-11-22 | 1958-08-19 | 0 | Details |
| US2847569A | Relaxation oscillator circuit | Expired / Lapsed | 1955-03-30 | 1958-08-12 | 0 | Details |
| US2847583A | Semiconductor devices and stabilization thereof | Expired / Lapsed | 1954-12-13 | 1958-08-12 | 0 | Details |
| US2846340A | Semiconductor devices and method of making same | Expired / Lapsed | 1956-06-18 | 1958-08-05 | 2 | Details |
| US2846502A | Automatic phasing for synchronous radio telegraph systems | Expired / Lapsed | 1955-09-29 | 1958-08-05 | 0 | Details |
| US2844638A | Heat pump | Expired / Lapsed | 1954-01-04 | 1958-07-22 | 0 | Details |
| US2844309A | Comparing system | Expired / Lapsed | 1952-11-20 | 1958-07-22 | 0 | Details |
| US2844434A | Magnetic recording | Expired / Lapsed | 1952-07-31 | 1958-07-22 | 0 | Details |
| US2841746A | Protective circuit | Expired / Lapsed | 1955-05-19 | 1958-07-01 | 0 | Details |
| US2841711A | Oscillation generator | Expired / Lapsed | 1953-09-23 | 1958-07-01 | 0 | Details |
| US2839936A | Uni-control tuning mechanism for multi-band signal receiver… | Expired / Lapsed | 1952-02-27 | 1958-06-24 | 0 | Details |
| US2838663A | Signal-amplitude responsive circuit | Expired / Lapsed | 1953-12-31 | 1958-06-10 | 0 | Details |
| US2836713A | Transistor radio receiver tuning indicator | Expired / Lapsed | 1956-08-17 | 1958-05-27 | 0 | Details |
| US2835804A | Wave generating systems | Expired / Lapsed | 1953-11-16 | 1958-05-20 | 0 | Details |
| US2832898A | Time delay transistor trigger circuit | Expired / Lapsed | 1954-07-12 | 1958-04-29 | 0 | Details |
| US2830177A | Signal receiver muting circuits | Expired / Lapsed | 1955-04-28 | 1958-04-08 | 0 | Details |
| US2829075A | Field controlled semiconductor devices and methods of makin… | Expired / Lapsed | 1954-09-09 | 1958-04-01 | 1 | Details |
| US2821571A | Communication system | Expired / Lapsed | 1956-03-30 | 1958-01-28 | 0 | Details |
| US2820844A | Color television systems | Expired / Lapsed | 1952-03-01 | 1958-01-21 | 0 | Details |
| US2820154A | Semiconductor devices | Expired / Lapsed | 1954-11-15 | 1958-01-14 | 0 | Details |
| US2819449A | Magnetron | Expired / Lapsed | 1954-01-21 | 1958-01-07 | 0 | Details |
| US2819456A | Memory system | Expired / Lapsed | 1953-03-26 | 1958-01-07 | 0 | Details |
| US2818532A | Single action timing circuit | Expired / Lapsed | 1955-11-01 | 1957-12-31 | 0 | Details |
| US2818555A | Magnetic control systems | Expired / Lapsed | 1955-07-27 | 1957-12-31 | 0 | Details |
| US2818523A | Storage tube | Expired / Lapsed | 1954-02-03 | 1957-12-31 | 0 | Details |
| US2817782A | Cathode ray tube deflection apparatus | Expired / Lapsed | 1954-07-09 | 1957-12-24 | 0 | Details |
| US2817265A | Light dividing apparatus | Expired / Lapsed | 1953-11-25 | 1957-12-24 | 0 | Details |
| US2817799A | Semi-conductor devices employing cadmium telluride | Expired / Lapsed | 1953-11-25 | 1957-12-24 | 2 | Details |
| US2816964A | Stabilizing means for semi-conductor circuits | Expired / Lapsed | 1954-10-27 | 1957-12-17 | 0 | Details |
| US2817072A | Serial memory system | Expired / Lapsed | 1954-08-02 | 1957-12-17 | 0 | Details |
| US2816283A | Semiconductor null detector | Expired / Lapsed | 1956-03-30 | 1957-12-10 | 0 | Details |
| US2816228A | Semiconductor phase shift oscillator and device | Expired / Lapsed | 1953-05-21 | 1957-12-10 | 0 | Details |
| US2813221A | Electron beam traveling-wave tube | Expired / Lapsed | 1950-10-02 | 1957-11-12 | 0 | Details |
| US2811647A | Oscillator frequency drift compensation arrangement | Expired / Lapsed | 1956-04-09 | 1957-10-29 | 0 | Details |
| US2811708A | Selective calling system | Expired / Lapsed | 1955-02-25 | 1957-10-29 | 0 | Details |
| US2811653A | Semiconductor devices | Expired / Lapsed | 1953-05-22 | 1957-10-29 | 2 | Details |
| US2810901A | Magnetic logic systems | Expired / Lapsed | 1956-02-29 | 1957-10-22 | 0 | Details |
| US2810888A | Electromechanical filter | Expired / Lapsed | 1954-08-03 | 1957-10-22 | 0 | Details |
| US2809332A | Power semiconductor devices | Expired / Lapsed | 1953-07-29 | 1957-10-08 | 2 | Details |
| US2808510A | Apparatus utilizing atomic or molecular beams | Expired / Lapsed | 1955-01-26 | 1957-10-01 | 0 | Details |
| US2808471A | Temperature-compensated semi-conductor signal amplifier cir… | Expired / Lapsed | 1954-05-25 | 1957-10-01 | 0 | Details |
| US2807664A | Information translating system | Expired / Lapsed | 1953-12-31 | 1957-09-24 | 0 | Details |
| US2807663A | Electronic character selecting and/or printing apparatus | Expired / Lapsed | 1950-10-02 | 1957-09-24 | 0 | Details |
| US2806963A | Regulated power supplies | Expired / Lapsed | 1955-06-24 | 1957-09-17 | 0 | Details |
| US2806944A | Switching system for standby receiver and transmitter | Expired / Lapsed | 1955-04-20 | 1957-09-17 | 0 | Details |
| US2806651A | Pulse amplitude analyzer | Expired / Lapsed | 1954-02-01 | 1957-09-17 | 0 | Details |
| US2806163A | Triple gun for color television | Expired / Lapsed | 1954-08-18 | 1957-09-10 | 0 | Details |
| US2805279A | Telegraph receiving station | Expired / Lapsed | 1955-06-21 | 1957-09-03 | 0 | Details |
| US2804500A | Color interpretation system | Expired / Lapsed | 1953-10-01 | 1957-08-27 | 0 | Details |
| US2802071A | Stabilizing means for semi-conductor circuits | Expired / Lapsed | 1954-03-31 | 1957-08-06 | 0 | Details |
| US2802067A | Symmetrical direct current stabilization in semiconductor a… | Expired / Lapsed | 1953-09-30 | 1957-08-06 | 0 | Details |
| US2802065A | Cascade connected common base transistor amplifier using co… | Expired / Lapsed | 1953-02-13 | 1957-08-06 | 0 | Details |
| US2802135A | Traveling wave electron tube | Expired / Lapsed | 1952-08-22 | 1957-08-06 | 0 | Details |
| US2801348A | Semiconductor devices | Expired / Lapsed | 1954-05-03 | 1957-07-30 | 2 | Details |
| US2800617A | Semiconductor devices | Expired / Lapsed | 1954-06-01 | 1957-07-23 | 0 | Details |
| US2800448A | Cataphoretic coating machine | Expired / Lapsed | 1954-04-30 | 1957-07-23 | 2 | Details |
| US2798960A | Photoconductive thermography | Expired / Lapsed | 1956-12-24 | 1957-07-09 | 0 | Details |
| US2798667A | Code converter system | Expired / Lapsed | 1953-02-18 | 1957-07-09 | 0 | Details |
| US2797327A | Semi-conductor sawtooth wave generator | Expired / Lapsed | 1954-11-17 | 1957-06-25 | 0 | Details |
| US2797256A | Dichroic reflector optical system | Expired / Lapsed | 1951-09-25 | 1957-06-25 | 0 | Details |
| US2796597A | Switching system | Expired / Lapsed | 1955-07-15 | 1957-06-18 | 0 | Details |
| US2796533A | Logarithmic count rate or frequency meter | Expired / Lapsed | 1953-04-27 | 1957-06-18 | 0 | Details |
| US2792989A | Means for locating the position of a mobile craft | Expired / Lapsed | 1953-06-30 | 1957-05-21 | 0 | Details |
| US2792447A | Electroluminescent color image reproduction | Expired / Lapsed | 1955-04-21 | 1957-05-14 | 0 | Details |
| US2792563A | Magnetic system | Expired / Lapsed | 1954-02-01 | 1957-05-14 | 0 | Details |
| US2792548A | Systems and methods of gas analysis | Expired / Lapsed | 1945-05-28 | 1957-05-14 | 0 | Details |
| US2791644A | Push-pull amplifier with complementary type transistors | Expired / Lapsed | 1952-11-07 | 1957-05-07 | 0 | Details |
| US2790896A | Radio receiving system | Expired / Lapsed | 1955-07-01 | 1957-04-30 | 0 | Details |
| US2788493A | Modulated semi-conductor oscillator circuit | Expired / Lapsed | 1953-10-28 | 1957-04-09 | 0 | Details |
| US2785389A | Magnetic switching system | Expired / Lapsed | 1955-04-29 | 1957-03-12 | 0 | Details |
| US2784390A | Static magnetic memory | Expired / Lapsed | 1953-11-27 | 1957-03-05 | 0 | Details |
| US2784391A | Memory system | Expired / Lapsed | 1953-08-20 | 1957-03-05 | 0 | Details |
| US2784256A | Bandwidth reduction system | Expired / Lapsed | 1951-01-25 | 1957-03-05 | 0 | Details |
| US2782263A | Magnetic recording and reproducing apparatus | Expired / Lapsed | 1955-10-31 | 1957-02-19 | 0 | Details |
| US2782355A | Web feeding means | Expired / Lapsed | 1955-09-30 | 1957-02-19 | 0 | Details |
| US2782399A | Magnetic switching device | Expired / Lapsed | 1953-03-02 | 1957-02-19 | 0 | Details |
| US2782303A | Switching system | Expired / Lapsed | 1952-04-30 | 1957-02-19 | 0 | Details |
| US2782043A | Magnetic tape | Expired / Lapsed | 1950-08-22 | 1957-02-19 | 0 | Details |
| US2781445A | Circuit for continuously corrected storage | Expired / Lapsed | 1953-05-20 | 1957-02-12 | 0 | Details |
| US2777057A | Radiation powered transistor circuits | Expired / Lapsed | 1952-12-16 | 1957-01-08 | 0 | Details |
| US2776420A | Transistor indicator circuits | Expired / Lapsed | 1954-11-01 | 1957-01-01 | 0 | Details |
| US2776419A | Magnetic memory system | Expired / Lapsed | 1953-05-08 | 1957-01-01 | 0 | Details |
| US2774067A | Microwave scanning antenna system | Expired / Lapsed | 1949-08-17 | 1956-12-11 | 0 | Details |
| US2772387A | Power supply with regulated positive and negative output vo… | Expired / Lapsed | 1953-10-29 | 1956-11-27 | 0 | Details |
| US2770732A | Transistor multivibrator circuit | Expired / Lapsed | 1955-07-08 | 1956-11-13 | 0 | Details |
| US2770722A | Time shift re-entrant amplifier system for carrier pulses | Expired / Lapsed | 1955-06-30 | 1956-11-13 | 0 | Details |
| US2770728A | Semi-conductor frequency multiplier circuit | Expired / Lapsed | 1954-07-26 | 1956-11-13 | 0 | Details |
| US2769907A | Semi-conductor relaxation oscillator circuits | Expired / Lapsed | 1954-06-29 | 1956-11-06 | 0 | Details |
| US2769857A | Automatic phasing of synchronous multiplex telegraph systems | Expired / Lapsed | 1954-02-01 | 1956-11-06 | 0 | Details |
| US2768475A | Method of making glass-to-metal seal | Expired / Lapsed | 1952-11-28 | 1956-10-30 | 0 | Details |
| US2768367A | Magnetic memory and magnetic switch systems | Expired / Lapsed | 1954-12-30 | 1956-10-23 | 0 | Details |
| US2768310A | Distributed gap electroluminescent device | Expired / Lapsed | 1954-12-28 | 1956-10-23 | 0 | Details |
| US2768296A | Semi-conductor phase controlled oscillator circuits | Expired / Lapsed | 1954-08-23 | 1956-10-23 | 0 | Details |
| US2768290A | Telegraph phase shifting equipment | Expired / Lapsed | 1953-04-23 | 1956-10-23 | 0 | Details |
| US2768372A | Randomly pulsed radio ranging system | Expired / Lapsed | 1952-12-30 | 1956-10-23 | 0 | Details |
| US2764697A | Image scanning system | Expired / Lapsed | 1950-11-02 | 1956-09-25 | 0 | Details |
| US2762873A | Transistor bias circuit with stabilization | Expired / Lapsed | 1953-06-30 | 1956-09-11 | 0 | Details |
| US2762870A | Push-pull complementary type transistor amplifier | Expired / Lapsed | 1953-05-28 | 1956-09-11 | 0 | Details |
| US2762875A | Stabilized cascade-connected semi-conductor amplifier circu… | Expired / Lapsed | 1952-11-15 | 1956-09-11 | 0 | Details |
| US2762862A | Electronic character selecting and/or printing apparatus | Expired / Lapsed | 1951-03-01 | 1956-09-11 | 0 | Details |
| US2762013A | Flutter measurement | Expired / Lapsed | 1954-11-01 | 1956-09-04 | 0 | Details |
| US2761916A | Self-biasing semi-conductor amplifier circuits and the like | Expired / Lapsed | 1952-11-15 | 1956-09-04 | 0 | Details |
| US2761060A | Auto alarm systems | Expired / Lapsed | 1952-08-01 | 1956-08-28 | 0 | Details |
| US2760137A | Motor control for synchronizing web feed | Expired / Lapsed | 1952-08-30 | 1956-08-21 | 0 | Details |
| US2760008A | Amplifier having controllable signal expansion and compress… | Expired / Lapsed | 1950-08-30 | 1956-08-21 | 0 | Details |
| US2759133A | Semiconductor devices | Expired / Lapsed | 1952-10-22 | 1956-08-14 | 4 | Details |
| US2758146A | Thermoelectric elements and materials | Expired / Lapsed | 1954-10-01 | 1956-08-07 | 2 | Details |
| US2758221A | Magnetic switching device | Expired / Lapsed | 1952-11-05 | 1956-08-07 | 0 | Details |
| US2757236A | Vertical aperture compensation for cathode ray apparatus | Expired / Lapsed | 1955-08-01 | 1956-07-31 | 0 | Details |
| US2756741A | Apparatus for obtaining systolic information | Expired / Lapsed | 1954-04-29 | 1956-07-31 | 0 | Details |
| US2757144A | Fluoride phosphors | Expired / Lapsed | 1954-02-24 | 1956-07-31 | 1 | Details |
| US2757226A | Secret television systems | Expired / Lapsed | 1950-10-23 | 1956-07-31 | 0 | Details |
| US2756378A | Protective circuit | Expired / Lapsed | 1953-05-27 | 1956-07-24 | 0 | Details |
| US2756278A | Magnetic film erasing method and system | Expired / Lapsed | 1950-05-13 | 1956-07-24 | 0 | Details |
| US2754455A | Power Transistors | Expired / Lapsed | 1952-11-29 | 1956-07-10 | 0 | Details |
| US2753280A | Method and apparatus for growing crystalline material | Expired / Lapsed | 1952-05-01 | 1956-07-03 | 2 | Details |
| US2751433A | Character analyzing systems | Expired / Lapsed | 1952-07-28 | 1956-06-19 | 0 | Details |
| US2750496A | V. h. f.-u. h. f. receiver having local oscillator converti… | Expired / Lapsed | 1955-03-31 | 1956-06-12 | 0 | Details |
| US2750534A | Television receiver | Expired / Lapsed | 1952-08-16 | 1956-06-12 | 0 | Details |
| US2750510A | Free-running square wave generator | Expired / Lapsed | 1952-01-16 | 1956-06-12 | 0 | Details |
| US2750452A | Selectivity control circuit | Expired / Lapsed | 1951-03-21 | 1956-06-12 | 0 | Details |
| US2750502A | Cathode-controlled wave generators | Expired / Lapsed | 1950-12-29 | 1956-06-12 | 0 | Details |
| US2748325A | Semi-conductor devices and methods for treating same | Expired / Lapsed | 1953-04-16 | 1956-05-29 | 1 | Details |
| US2747111A | Coupling circuit for semi-conductor devices | Expired / Lapsed | 1953-07-02 | 1956-05-22 | 0 | Details |
| US2745038A | Semiconductor signal translating circuit | Expired / Lapsed | 1954-10-26 | 1956-05-08 | 0 | Details |
| US2744955A | Reversible electronic code translators | Expired / Lapsed | 1953-08-24 | 1956-05-08 | 0 | Details |
| US2745021A | Photo device amplifier circuit | Expired / Lapsed | 1951-11-23 | 1956-05-08 | 0 | Details |
| US2745032A | Photo-conductive targets for cathode ray devices | Expired / Lapsed | 1951-06-01 | 1956-05-08 | 0 | Details |
| US2744155A | Color or monochrome television receiving system | Expired / Lapsed | 1950-05-01 | 1956-05-01 | 0 | Details |
| US2743430A | Information storage devices | Expired / Lapsed | 1952-03-01 | 1956-04-24 | 0 | Details |
| US2743369A | Oscillation control circuits | Expired / Lapsed | 1952-01-30 | 1956-04-24 | 0 | Details |
| US2743354A | Frequency shift signalling | Expired / Lapsed | 1951-07-27 | 1956-04-24 | 0 | Details |
| US2743366A | Frequency-stabilization by particle beams | Expired / Lapsed | 1949-07-22 | 1956-04-24 | 0 | Details |
| US2742632A | Magnetic switching circuit | Expired / Lapsed | 1954-12-30 | 1956-04-17 | 0 | Details |
| US2742631A | Method and apparatus for recording and transmitting informa… | Expired / Lapsed | 1954-05-27 | 1956-04-17 | 2 | Details |
| US2742571A | Junction transistor oscillator circuit | Expired / Lapsed | 1953-12-31 | 1956-04-17 | 0 | Details |
| US2741756A | Electrical data storage device | Expired / Lapsed | 1953-07-16 | 1956-04-10 | 0 | Details |
| US2740889A | Stable ultra-high frequency oscillation generator | Expired / Lapsed | 1951-07-31 | 1956-04-03 | 0 | Details |
| US2739234A | Step wave generators | Expired / Lapsed | 1951-02-27 | 1956-03-20 | 0 | Details |
| US2731609A | Sliding connector for printed circuit boards | Expired / Lapsed | 1954-09-29 | 1956-01-17 | 0 | Details |
| US2731631A | Code converter circuit | Expired / Lapsed | 1952-10-31 | 1956-01-17 | 0 | Details |
| US2730683A | Sliding connector | Expired / Lapsed | 1954-09-29 | 1956-01-10 | 0 | Details |
| US2730700A | Error avoidance system for information handling machines | Expired / Lapsed | 1950-11-24 | 1956-01-10 | 0 | Details |
| US2729698A | Electrical filters | Expired / Lapsed | 1954-09-22 | 1956-01-03 | 0 | Details |
| US2729816A | Lens antenna | Expired / Lapsed | 1954-08-30 | 1956-01-03 | 0 | Details |
| US2729708A | Band-pass amplifier systems | Expired / Lapsed | 1951-02-02 | 1956-01-03 | 0 | Details |
| US2728857A | Electronic switching | Expired / Lapsed | 1952-09-09 | 1955-12-27 | 0 | Details |
| US2725505A | Semiconductor power devices | Expired / Lapsed | 1953-11-30 | 1955-11-29 | 2 | Details |
| US2725530A | Quantizing apparatus | Expired / Lapsed | 1950-10-12 | 1955-11-29 | 0 | Details |
| US2724739A | Code conversion system | Expired / Lapsed | 1953-06-16 | 1955-11-22 | 0 | Details |
| FR1103565A | Method and apparatus for manufacturing semiconductor devices | Expired / Lapsed | 1954-04-22 | 1955-11-04 | 0 | Details |
| US2720090A | Air conditioning control | Expired / Lapsed | 1954-04-23 | 1955-10-11 | 0 | Details |
| US2719965A | Magnetic memory matrix writing system | Expired / Lapsed | 1954-06-15 | 1955-10-04 | 0 | Details |
| US2719799A | Zone melting furnace and method of zone melting | Expired / Lapsed | 1952-11-13 | 1955-10-04 | 1 | Details |
| US2719959A | Parity check system | Expired / Lapsed | 1952-10-31 | 1955-10-04 | 0 | Details |
| US2718552A | Noise cancellation circuit | Expired / Lapsed | 1951-05-26 | 1955-09-20 | 0 | Details |
| US2717276A | Color television system | Expired / Lapsed | 1953-08-11 | 1955-09-06 | 0 | Details |
| US2716189A | Frequency selective circuit | Expired / Lapsed | 1952-09-30 | 1955-08-23 | 0 | Details |
| US2715211A | Ultra high frequency tuning systems | Expired / Lapsed | 1950-02-02 | 1955-08-09 | 0 | Details |
| US2709229A | Radioactive monokinetic charged particle generators | Expired / Lapsed | 1950-06-01 | 1955-05-24 | 2 | Details |
| US2707899A | Low-reflecting glass | Expired / Lapsed | 1951-08-28 | 1955-05-10 | 4 | Details |
| US2708249A | Ultra high frequency electron tube | Expired / Lapsed | 1950-12-05 | 1955-05-10 | 0 | Details |
| US2707233A | Frequency stabilization | Expired / Lapsed | 1951-07-16 | 1955-04-26 | 0 | Details |
| US2707249A | Discharge gage control of vacuum systems | Expired / Lapsed | 1951-02-02 | 1955-04-26 | 0 | Details |
| US2707208A | Secrecy facsimile system | Expired / Lapsed | 1945-03-31 | 1955-04-26 | 0 | Details |
| US2706286A | Fault locating and indicating system | Expired / Lapsed | 1951-09-04 | 1955-04-12 | 0 | Details |
| US2705261A | Electronic telegraph signal redistributors | Expired / Lapsed | 1954-03-15 | 1955-03-29 | 0 | Details |
| US2705287A | Pulse controlled oscillator systems | Expired / Lapsed | 1954-03-01 | 1955-03-29 | 0 | Details |
| US2705284A | Frequency stabilization system | Expired / Lapsed | 1948-11-04 | 1955-03-29 | 0 | Details |
| US2704829A | Delay line | Expired / Lapsed | 1951-10-01 | 1955-03-22 | 0 | Details |
| US2704340A | Semiconductor devices and their manufacture | Expired / Lapsed | 1953-06-05 | 1955-03-15 | 0 | Details |
| US2702380A | Data translating system | Expired / Lapsed | 1953-12-24 | 1955-02-15 | 0 | Details |
| US2702315A | Sound record transfer method and system | Expired / Lapsed | 1951-05-01 | 1955-02-15 | 0 | Details |
| US2702274A | Method of making an electrode screen by cathode sputtering | Expired / Lapsed | 1951-04-02 | 1955-02-15 | 2 | Details |
| US2702316A | Signal modulation system | Expired / Lapsed | 1951-02-28 | 1955-02-15 | 0 | Details |
| US2702367A | Electronic counter | Expired / Lapsed | 1947-12-30 | 1955-02-15 | 0 | Details |
| US2702382A | Radio pulse-echo locator system for detecting moving objects | Expired / Lapsed | 1944-04-10 | 1955-02-15 | 0 | Details |
| US2701302A | Semiconductor frequency converter | Expired / Lapsed | 1951-03-29 | 1955-02-01 | 0 | Details |
| US2698386A | Push-pull sine wave oscillator | Expired / Lapsed | 1950-11-21 | 1954-12-28 | 0 | Details |
| US2696739A | Temperature responsive semiconductor circuits | Expired / Lapsed | 1951-07-05 | 1954-12-14 | 0 | Details |
| US2696347A | Magnetic switching circuit | Expired / Lapsed | 1953-06-19 | 1954-12-07 | 0 | Details |
| US2696600A | Combinatorial information-storage network | Expired / Lapsed | 1950-11-30 | 1954-12-07 | 0 | Details |
| FR1080034A | Semiconductor device enhancements | Expired / Lapsed | 1953-05-05 | 1954-12-06 | 0 | Details |
| US2695357A | Frequency conversion apparatus | Expired / Lapsed | 1951-04-19 | 1954-11-23 | 0 | Details |
| US2692333A | Wave shaping circuit | Expired / Lapsed | 1951-08-02 | 1954-10-19 | 0 | Details |
| US2692077A | Package for radio tubes and the like | Expired / Lapsed | 1948-12-11 | 1954-10-19 | 0 | Details |
| US2691157A | Magnetic memory switching system | Expired / Lapsed | 1953-06-26 | 1954-10-05 | 0 | Details |
| US2691156A | Magnetic memory reading system | Expired / Lapsed | 1953-05-29 | 1954-10-05 | 0 | Details |
| US2691116A | Color-kinescopes, etc. | Expired / Lapsed | 1953-03-31 | 1954-10-05 | 0 | Details |
| US2691155A | Memory system | Expired / Lapsed | 1953-02-20 | 1954-10-05 | 0 | Details |
| US2691152A | Magnetic switching system | Expired / Lapsed | 1953-01-13 | 1954-10-05 | 0 | Details |
| US2691153A | Magnetic swtiching system | Expired / Lapsed | 1953-01-13 | 1954-10-05 | 0 | Details |
| US2691154A | Magnetic information handling system | Expired / Lapsed | 1952-03-08 | 1954-10-05 | 0 | Details |
| US2691077A | Transistor power amplifier | Expired / Lapsed | 1951-03-31 | 1954-10-05 | 0 | Details |
| US2691076A | Semiconductor signal translating system | Expired / Lapsed | 1951-01-18 | 1954-10-05 | 0 | Details |
| US2691065A | Multiplex relay system | Expired / Lapsed | 1951-01-12 | 1954-10-05 | 0 | Details |
| US2691075A | Transistor amplifier with high undistorted output | Expired / Lapsed | 1950-06-27 | 1954-10-05 | 0 | Details |
| US2691074A | Amplifier having frequency responsive variable gain | Expired / Lapsed | 1949-08-31 | 1954-10-05 | 0 | Details |
| US2689271A | Color television camera | Expired / Lapsed | 1952-04-05 | 1954-09-14 | 0 | Details |
| US2688897A | Testing motion-picture cameras | Expired / Lapsed | 1949-12-30 | 1954-09-14 | 0 | Details |
| US2688742A | Smooth tracking of input voltage | Expired / Lapsed | 1951-07-31 | 1954-09-07 | 0 | Details |
| US2688564A | Method of forming cadmium sulfide photoconductive cells | Expired / Lapsed | 1950-11-22 | 1954-09-07 | 2 | Details |
| US2687484A | Photoconductive target | Expired / Lapsed | 1951-02-24 | 1954-08-24 | 0 | Details |
| US2686879A | Wide range ultrahigh-frequency oscillator | Expired / Lapsed | 1951-10-29 | 1954-08-17 | 0 | Details |
| US2686276A | Wave generating system | Expired / Lapsed | 1950-08-25 | 1954-08-10 | 0 | Details |
| US2686229A | Magnetic record copying | Expired / Lapsed | 1949-04-16 | 1954-08-10 | 0 | Details |
| US2686220A | Conveyeance of auxiliary information in a television system | Expired / Lapsed | 1948-05-28 | 1954-08-10 | 0 | Details |
| US2685618A | Wide range magnetic recording system and method | Expired / Lapsed | 1951-12-29 | 1954-08-03 | 0 | Details |
| US2685000A | Stabilized direct current amplifier | Expired / Lapsed | 1949-04-29 | 1954-07-27 | 0 | Details |
| US2684999A | Stabilized direct current amplifier | Expired / Lapsed | 1949-04-28 | 1954-07-27 | 0 | Details |
| US2684442A | Multivibrator | Expired / Lapsed | 1951-07-31 | 1954-07-20 | 0 | Details |
| US2682574A | Electronic diplex transmitting distributor | Expired / Lapsed | 1952-03-29 | 1954-06-29 | 0 | Details |
| US2679187A | Synchronization of separate picture and sound films | Expired / Lapsed | 1951-01-16 | 1954-05-25 | 0 | Details |
| US2677721A | Color television system | Expired / Lapsed | 1949-09-24 | 1954-05-04 | 0 | Details |
| US2677059A | Signal generator | Expired / Lapsed | 1951-03-06 | 1954-04-27 | 0 | Details |
| US2677128A | System for improving the signal-tonoise ratio in repetitive… | Expired / Lapsed | 1950-12-29 | 1954-04-27 | 0 | Details |
| US2677119A | Ground controlled aircraft communication system | Expired / Lapsed | 1950-07-24 | 1954-04-27 | 0 | Details |
| US2677071A | Voltage reference tube | Expired / Lapsed | 1948-06-30 | 1954-04-27 | 0 | Details |
| US2676275A | Piezoelectric crystal apparatus | Expired / Lapsed | 1953-02-02 | 1954-04-20 | 0 | Details |
| US2676253A | Electronic comparing circuit | Expired / Lapsed | 1952-01-30 | 1954-04-20 | 0 | Details |
| US2676200A | Television scanning system | Expired / Lapsed | 1950-11-09 | 1954-04-20 | 0 | Details |
| US2676317A | Pulse echo radar system employing a double channel | Expired / Lapsed | 1945-01-12 | 1954-04-20 | 0 | Details |
| US2675433A | Degenerative amplifier | Expired / Lapsed | 1950-04-27 | 1954-04-13 | 0 | Details |
| US2674660A | Artificial reverberation | Expired / Lapsed | 1952-12-10 | 1954-04-06 | 0 | Details |
| US2674727A | Parity generator | Expired / Lapsed | 1952-10-14 | 1954-04-06 | 0 | Details |
| US2673896A | Magnetic record erasing transducer | Expired / Lapsed | 1951-12-29 | 1954-03-30 | 0 | Details |
| US2673956A | Time interval measurement | Expired / Lapsed | 1949-09-22 | 1954-03-30 | 0 | Details |
| US2673236A | Signaling code converter | Expired / Lapsed | 1951-12-19 | 1954-03-23 | 0 | Details |
| US2671275A | Magnetometer | Expired / Lapsed | 1949-03-31 | 1954-03-09 | 0 | Details |
| US2669663A | Semiconductor photoconducting device | Expired / Lapsed | 1951-11-30 | 1954-02-16 | 2 | Details |
| US2668869A | Radio viewing system | Expired / Lapsed | 1945-02-26 | 1954-02-09 | 0 | Details |
| US2668190A | Television image pickup system | Expired / Lapsed | 1947-07-05 | 1954-02-02 | 0 | Details |
| US2667621A | Torsional filter | Expired / Lapsed | 1950-06-07 | 1954-01-26 | 0 | Details |
| US2666902A | Frequency modulator transistor circuits | Expired / Lapsed | 1950-06-30 | 1954-01-19 | 0 | Details |
| US2666151A | Magnetic switching device | Expired / Lapsed | 1952-11-28 | 1954-01-12 | 0 | Details |
| US2664462A | Multiplexed signal transmission | Expired / Lapsed | 1949-08-31 | 1953-12-29 | 0 | Details |
| US2663800A | Frequency controlled oscillator system | Expired / Lapsed | 1952-11-15 | 1953-12-22 | 0 | Details |
| US2662976A | Semiconductor amplifier and rectifier | Expired / Lapsed | 1949-03-31 | 1953-12-15 | 0 | Details |
| US2662938A | Coupling circuit for use in cathode coupled circuits | Expired / Lapsed | 1949-03-29 | 1953-12-15 | 0 | Details |
| US2661391A | Mechanical color filter device for use in sequential televi… | Expired / Lapsed | 1950-12-22 | 1953-12-01 | 0 | Details |
| US2660624A | High input impedance semiconductor amplifier | Expired / Lapsed | 1949-02-24 | 1953-11-24 | 0 | Details |
| US2658670A | Rate determining device | Expired / Lapsed | 1949-08-31 | 1953-11-10 | 0 | Details |
| US2657870A | Motor drive system for motionpicture equipment | Expired / Lapsed | 1950-10-31 | 1953-11-03 | 0 | Details |
| US2657932A | Combination photographic and magnetic sound record and meth… | Expired / Lapsed | 1949-04-16 | 1953-11-03 | 0 | Details |
| US2655650A | Radar ground approach system | Expired / Lapsed | 1951-03-19 | 1953-10-13 | 0 | Details |
| US2655556A | Synchronizing system | Expired / Lapsed | 1949-12-30 | 1953-10-13 | 0 | Details |
| US2654852A | Photoconductive target for cathode-ray devices | Expired / Lapsed | 1951-06-01 | 1953-10-06 | 1 | Details |
| US2654841A | Frequency discriminator | Expired / Lapsed | 1950-10-20 | 1953-10-06 | 0 | Details |
| US2654853A | Photoelectric apparatus | Expired / Lapsed | 1949-02-28 | 1953-10-06 | 0 | Details |
| US2651673A | Frequency discriminatory system | Expired / Lapsed | 1949-09-20 | 1953-09-08 | 0 | Details |
| US2646545A | Amplitude linearity measurement | Expired / Lapsed | 1951-06-26 | 1953-07-21 | 0 | Details |
| US2646542A | High-voltage system | Expired / Lapsed | 1951-03-22 | 1953-07-21 | 0 | Details |
| US2645971A | Surface contour measurement | Expired / Lapsed | 1949-06-28 | 1953-07-21 | 0 | Details |
| US2645712A | Reading circuit for storage tubes | Expired / Lapsed | 1949-12-01 | 1953-07-14 | 0 | Details |
| US2644897A | Transistor ring counter | Expired / Lapsed | 1952-08-09 | 1953-07-07 | 0 | Details |
| US2644896A | Transistor bistable circuit | Expired / Lapsed | 1952-07-29 | 1953-07-07 | 0 | Details |
| US2644892A | Transistor pulse memory circuits | Expired / Lapsed | 1952-06-02 | 1953-07-07 | 0 | Details |
| US2644893A | Semiconductor pulse memory circuits | Expired / Lapsed | 1952-06-02 | 1953-07-07 | 0 | Details |
| US2644885A | Diversity gating system | Expired / Lapsed | 1951-02-27 | 1953-07-07 | 0 | Details |
| US2644933A | Multichannel telemetering apparatus | Expired / Lapsed | 1949-12-28 | 1953-07-07 | 0 | Details |
| US2643368A | Pulse signal decoding system | Expired / Lapsed | 1951-02-02 | 1953-06-23 | 0 | Details |
| US2641642A | Color television camera | Expired / Lapsed | 1951-12-29 | 1953-06-09 | 0 | Details |
| US2641643A | Color television camera | Expired / Lapsed | 1950-12-01 | 1953-06-09 | 0 | Details |
| US2639859A | Transitory memory circuits | Expired / Lapsed | 1950-11-29 | 1953-05-26 | 0 | Details |
| US2639322A | Facsimile scanner | Expired / Lapsed | 1948-10-30 | 1953-05-19 | 0 | Details |
| US2639324A | Tuned inductive coupling system | Expired / Lapsed | 1948-04-29 | 1953-05-19 | 0 | Details |
| US2638499A | Color television system | Expired / Lapsed | 1950-01-24 | 1953-05-12 | 0 | Details |
| US2638538A | Automatic gain control system | Expired / Lapsed | 1949-05-27 | 1953-05-12 | 0 | Details |
| US2638587A | Pulse echo altimeter with mechanically driven indicator | Expired / Lapsed | 1949-02-18 | 1953-05-12 | 0 | Details |
| US2637767A | Wide band microwave spectroscopy | Expired / Lapsed | 1949-07-16 | 1953-05-05 | 0 | Details |
| US2636936A | Television secrecy system | Expired / Lapsed | 1946-09-10 | 1953-04-28 | 0 | Details |
| US2636166A | Bearing deviation indication system | Expired / Lapsed | 1947-09-10 | 1953-04-21 | 0 | Details |
| US2634323A | High gain semiconductor amplifier | Expired / Lapsed | 1949-12-28 | 1953-04-07 | 0 | Details |
| US2634322A | Contact for semiconductor devices | Expired / Lapsed | 1949-07-16 | 1953-04-07 | 0 | Details |
| US2634324A | Color television | Expired / Lapsed | 1948-12-01 | 1953-04-07 | 0 | Details |
| US2632845A | Coincidence indicator | Expired / Lapsed | 1950-12-22 | 1953-03-24 | 0 | Details |
| US2632157A | Radio navigation system | Expired / Lapsed | 1945-07-31 | 1953-03-17 | 0 | Details |
| US2631259A | Color television | Expired / Lapsed | 1950-07-12 | 1953-03-10 | 0 | Details |
| US2629858A | Transistor amplitude modulator | Expired / Lapsed | 1950-12-29 | 1953-02-24 | 0 | Details |
| US2629767A | Semiconductor amplifier or oscillator device | Expired / Lapsed | 1949-08-31 | 1953-02-24 | 0 | Details |
| US2629000A | Distortion analyzing apparatus | Expired / Lapsed | 1950-05-26 | 1953-02-17 | 0 | Details |
| US2629026A | Muting system for signal amplifiers | Expired / Lapsed | 1949-05-28 | 1953-02-17 | 0 | Details |
| US2628104A | Induction heating of recording styli | Expired / Lapsed | 1950-03-31 | 1953-02-10 | 0 | Details |
| US2628277A | Relay type selecting circuit arrangement | Expired / Lapsed | 1949-12-21 | 1953-02-10 | 0 | Details |
| US2628284A | Magnetic transducer | Expired / Lapsed | 1949-10-31 | 1953-02-10 | 0 | Details |
| US2628279A | Automatic phase control circuit | Expired / Lapsed | 1949-03-31 | 1953-02-10 | 0 | Details |
| US2627596A | Driving apparatus | Expired / Lapsed | 1950-05-31 | 1953-02-03 | 0 | Details |
| US2627576A | Saw-tooth wave generator | Expired / Lapsed | 1949-02-01 | 1953-02-03 | 0 | Details |
| US2627547A | Gamma control | Expired / Lapsed | 1948-04-29 | 1953-02-03 | 0 | Details |
| US2625734A | Art of making color-kinescopes, etc. | Expired / Lapsed | 1950-04-28 | 1953-01-20 | 0 | Details |
| US2625602A | Film pulldown mechanism for television | Expired / Lapsed | 1947-06-26 | 1953-01-13 | 0 | Details |
| US2621244A | Color television registration system | Expired / Lapsed | 1950-11-29 | 1952-12-09 | 0 | Details |
| US2621250A | Relay storage and switching arrangement | Expired / Lapsed | 1949-12-10 | 1952-12-09 | 0 | Details |
| US2621245A | Color scanning system | Expired / Lapsed | 1947-09-09 | 1952-12-09 | 0 | Details |
| US2619608A | Post-deflected color kinescope | Expired / Lapsed | 1950-09-14 | 1952-11-25 | 0 | Details |
| US2619618A | Energy storage counter | Expired / Lapsed | 1950-01-07 | 1952-11-25 | 0 | Details |
| US2619587A | Diversity receiving system | Expired / Lapsed | 1949-07-23 | 1952-11-25 | 0 | Details |
| US2617882A | Maximal flatness filter | Expired / Lapsed | 1950-05-29 | 1952-11-11 | 0 | Details |
| US2617879A | Signal quantizer | Expired / Lapsed | 1948-06-18 | 1952-11-11 | 0 | Details |
| US2616983A | Apparatus for indicia recognition | Expired / Lapsed | 1949-01-03 | 1952-11-04 | 0 | Details |
| US2615990A | Magnetic recording and reproduction | Expired / Lapsed | 1949-06-18 | 1952-10-28 | 0 | Details |
| US2615976A | Color television system | Expired / Lapsed | 1947-11-20 | 1952-10-28 | 0 | Details |
| US2615147A | Electron tube protective system | Expired / Lapsed | 1951-04-10 | 1952-10-21 | 0 | Details |
| US2612632A | Regulated power supply | Expired / Lapsed | 1949-08-30 | 1952-09-30 | 0 | Details |
| US2611828A | Magnetic record editing device | Expired / Lapsed | 1950-05-31 | 1952-09-23 | 0 | Details |
| US2611010A | Printed circuit structure for highfrequency apparatus | Expired / Lapsed | 1949-07-30 | 1952-09-16 | 0 | Details |
| US2609688A | Humidity sensitive device | Expired / Lapsed | 1949-11-30 | 1952-09-09 | 2 | Details |
| US2610252A | Audio limiter circuits | Expired / Lapsed | 1948-12-15 | 1952-09-09 | 0 | Details |
| US2610292A | Fading compensation radio signaling system | Expired / Lapsed | 1946-03-12 | 1952-09-09 | 0 | Details |
| US2609441A | Combination radio television receiving system | Expired / Lapsed | 1949-12-01 | 1952-09-02 | 0 | Details |
| US2609428A | Base electrodes for semiconductor devices | Expired / Lapsed | 1949-08-31 | 1952-09-02 | 0 | Details |
| US2608656A | Microwave antenna | Expired / Lapsed | 1950-02-17 | 1952-08-26 | 0 | Details |
| US2607018A | Means and method for protecting kinescope screens | Expired / Lapsed | 1949-11-29 | 1952-08-12 | 0 | Details |
| US2605364A | Combination photographic and magnetic sound film picture pr… | Expired / Lapsed | 1949-10-29 | 1952-07-29 | 0 | Details |
| US2605306A | Semiconductor multivibrator circuit | Expired / Lapsed | 1949-10-15 | 1952-07-29 | 0 | Details |
| US2604533A | Amplitude modulation | Expired / Lapsed | 1949-03-08 | 1952-07-22 | 0 | Details |
| US2604263A | Variable frequency counter | Expired / Lapsed | 1947-05-22 | 1952-07-22 | 0 | Details |
| US2602835A | Microwave spectroscopy | Expired / Lapsed | 1949-03-30 | 1952-07-08 | 0 | Details |
| US2602920A | Radio location and detection arrangement | Expired / Lapsed | 1947-07-10 | 1952-07-08 | 0 | Details |
| US2600373A | Semiconductor translating device | Expired / Lapsed | 1951-01-18 | 1952-06-10 | 0 | Details |
| US2599643A | Radio transmission system | Expired / Lapsed | 1949-01-24 | 1952-06-10 | 0 | Details |
| US2600159A | Course interception navigational computer | Expired / Lapsed | 1948-08-13 | 1952-06-10 | 0 | Details |
| US2598925A | Method and means for generating electrical energy from a ra… | Expired / Lapsed | 1946-06-25 | 1952-06-03 | 0 | Details |
| US2598090A | Moistureproof protective membrane material and method of ma… | Expired / Lapsed | 1950-01-31 | 1952-05-27 | 4 | Details |
| US2598252A | Balance control for metal detection and inspection equipment | Expired / Lapsed | 1948-02-03 | 1952-05-27 | 0 | Details |
| US2595496A | Cascade-connected semiconductor amplifier | Expired / Lapsed | 1949-01-22 | 1952-05-06 | 0 | Details |
| US2595497A | Semiconductor device for two-stage amplifiers | Expired / Lapsed | 1949-01-22 | 1952-05-06 | 0 | Details |
| US2595553A | Color television system | Expired / Lapsed | 1947-10-30 | 1952-05-06 | 0 | Details |
| US2595548A | Picture reproducing apparatus | Expired / Lapsed | 1947-02-24 | 1952-05-06 | 0 | Details |
| US2595078A | Dielectric wave guide | Expired / Lapsed | 1948-05-28 | 1952-04-29 | 0 | Details |
| US2593616A | Electronic spectroscope | Expired / Lapsed | 1949-12-16 | 1952-04-22 | 0 | Details |
| US2593066A | Regulated power supply | Expired / Lapsed | 1947-09-23 | 1952-04-15 | 0 | Details |
| US2591961A | Transistor ring counter | Expired / Lapsed | 1950-11-28 | 1952-04-08 | 0 | Details |
| US2591792A | Frequency stabilization of radio frequency generators | Expired / Lapsed | 1947-07-31 | 1952-04-08 | 0 | Details |
| US2590281A | Television film scanner | Expired / Lapsed | 1948-08-13 | 1952-03-25 | 0 | Details |
| US2589494A | Stabilizing method and system utilizing nuclear precession | Expired / Lapsed | 1948-07-20 | 1952-03-18 | 0 | Details |
| US2589930A | Color television light divider | Expired / Lapsed | 1948-03-17 | 1952-03-18 | 0 | Details |
| US2588832A | Transmission line coupling | Expired / Lapsed | 1949-12-01 | 1952-03-11 | 0 | Details |
| US2587074A | Color television image reproducing system | Expired / Lapsed | 1948-09-29 | 1952-02-26 | 0 | Details |
| US2586482A | Pickup tube for color television | Expired / Lapsed | 1947-11-20 | 1952-02-19 | 0 | Details |
| US2584324A | Ceramic dielectric materials and method of making | Expired / Lapsed | 1950-12-30 | 1952-02-05 | 2 | Details |
| US2584600A | Radio-frequency phase shift network | Expired / Lapsed | 1948-06-29 | 1952-02-05 | 0 | Details |
| US2582850A | Photocell | Expired / Lapsed | 1949-03-03 | 1952-01-15 | 2 | Details |
| US2581487A | Color television reproduction tube | Expired / Lapsed | 1950-03-01 | 1952-01-08 | 0 | Details |
| US2581594A | Wide-range high stability frequency generating system | Expired / Lapsed | 1948-12-30 | 1952-01-08 | 0 | Details |
| US2580921A | Radio reflector | Expired / Lapsed | 1947-10-01 | 1952-01-01 | 0 | Details |
| US2580903A | Color television system | Expired / Lapsed | 1947-06-02 | 1952-01-01 | 0 | Details |
| US2579627A | Deflection system | Expired / Lapsed | 1950-06-22 | 1951-12-25 | 0 | Details |
| US2579705A | Color television system | Expired / Lapsed | 1950-01-27 | 1951-12-25 | 0 | Details |
| US2579996A | Frequency selective signal amplifying system | Expired / Lapsed | 1949-07-28 | 1951-12-25 | 0 | Details |
| US2580051A | Frequency converter and oscillator circuit | Expired / Lapsed | 1948-03-26 | 1951-12-25 | 0 | Details |
| US2579971A | Color television system | Expired / Lapsed | 1947-11-26 | 1951-12-25 | 0 | Details |
| US2579816A | Voltage regulator | Expired / Lapsed | 1947-04-05 | 1951-12-25 | 0 | Details |
| US2579163A | Electronic timing device | Expired / Lapsed | 1947-12-26 | 1951-12-18 | 0 | Details |
| US2578434A | High-frequency electron discharge device of the traveling w… | Expired / Lapsed | 1947-06-25 | 1951-12-11 | 0 | Details |
| US2575987A | Conducting rubber heating element | Expired / Lapsed | 1947-08-29 | 1951-11-20 | 0 | Details |
| US2575232A | Electron tube protective system | Expired / Lapsed | 1950-03-09 | 1951-11-13 | 0 | Details |
| US2574603A | Automatic selector mechanism | Expired / Lapsed | 1945-06-15 | 1951-11-13 | 0 | Details |
| US2573813A | Sequential pulse generator | Expired / Lapsed | 1948-09-30 | 1951-11-06 | 0 | Details |
| US2573777A | Television system | Expired / Lapsed | 1947-04-24 | 1951-11-06 | 0 | Details |
| US2572912A | Diversity system | Expired / Lapsed | 1948-03-01 | 1951-10-30 | 0 | Details |
| US2572497A | Making fine mesh silica screens | Expired / Lapsed | 1948-11-30 | 1951-10-23 | 1 | Details |
| US2571027A | Electron tube protective system | Expired / Lapsed | 1950-03-09 | 1951-10-09 | 0 | Details |
| US2570858A | Frequency analyzer | Expired / Lapsed | 1949-02-26 | 1951-10-09 | 0 | Details |
| US2570775A | Electrical timing comparator circuit | Expired / Lapsed | 1948-12-30 | 1951-10-09 | 0 | Details |
| US2570442A | Production of sharp pulses | Expired / Lapsed | 1948-05-21 | 1951-10-09 | 0 | Details |
| US2569691A | Impedance measuring | Expired / Lapsed | 1948-07-27 | 1951-10-02 | 0 | Details |
| US2569667A | Electrical filter unit | Expired / Lapsed | 1946-07-18 | 1951-10-02 | 0 | Details |
| US2568932A | Electronic cumulative adder | Expired / Lapsed | 1947-09-27 | 1951-09-25 | 0 | Details |
| US2568927A | Computing device | Expired / Lapsed | 1946-06-05 | 1951-09-25 | 0 | Details |
| US2566831A | Electronic counter | Expired / Lapsed | 1949-02-01 | 1951-09-04 | 0 | Details |
| US2567040A | Color television | Expired / Lapsed | 1947-12-26 | 1951-09-04 | 0 | Details |
| US2566085A | Electronic interval timing method and system | Expired / Lapsed | 1949-02-26 | 1951-08-28 | 0 | Details |
| US2566078A | Time-measuring and recording device | Expired / Lapsed | 1947-03-27 | 1951-08-28 | 0 | Details |
| US2564059A | Frequency control system for receivers | Expired / Lapsed | 1948-01-29 | 1951-08-14 | 0 | Details |
| US2562228A | Frequency divider | Expired / Lapsed | 1947-12-12 | 1951-07-31 | 0 | Details |
| US2560968A | Variable frequency counter | Expired / Lapsed | 1948-03-24 | 1951-07-17 | 0 | Details |
| US2560946A | Metal slug resonator | Expired / Lapsed | 1948-02-03 | 1951-07-17 | 0 | Details |
| US2560430A | Magneto-optical transducer system | Expired / Lapsed | 1949-08-27 | 1951-07-10 | 0 | Details |
| US2560234A | Mass production method of and apparatus for, making reelabl… | Expired / Lapsed | 1949-02-26 | 1951-07-10 | 0 | Details |
| US2559719A | Frequency-stabilizing method and system | Expired / Lapsed | 1948-09-25 | 1951-07-10 | 0 | Details |
| US2560351A | Simultaneous color television | Expired / Lapsed | 1946-12-14 | 1951-07-10 | 0 | Details |
| US2559505A | Art of making duplicate magnetic phonograph records | Expired / Lapsed | 1948-02-03 | 1951-07-03 | 0 | Details |
| US2558447A | High-speed frequency divider | Expired / Lapsed | 1948-12-30 | 1951-06-26 | 0 | Details |
| US2558532A | Cathode-ray screen coated with zinc or magnesium fluoride p… | Expired / Lapsed | 1945-04-19 | 1951-06-26 | 2 | Details |
| US2555829A | Television deflection power recovery circuit | Expired / Lapsed | 1949-04-30 | 1951-06-05 | 0 | Details |
| US2555475A | Radio receiver tuning mechanism | Expired / Lapsed | 1948-04-30 | 1951-06-05 | 0 | Details |
| US2555557A | Diversity receiver | Expired / Lapsed | 1947-02-25 | 1951-06-05 | 0 | Details |
| US2554693A | Simultaneous multicolor television | Expired / Lapsed | 1946-12-07 | 1951-05-29 | 0 | Details |
| US2554317A | Clamp circuit | Expired / Lapsed | 1946-12-18 | 1951-05-22 | 0 | Details |
| FR980661A | Electro-mechanical translator | Expired / Lapsed | 1949-02-12 | 1951-05-16 | 0 | Details |
| US2553165A | Relaxation oscillator | Expired / Lapsed | 1946-02-28 | 1951-05-15 | 0 | Details |
| US2551681A | Direct reading loran navigation system | Expired / Lapsed | 1949-02-26 | 1951-05-08 | 0 | Details |
| US2552386A | Color television camera | Expired / Lapsed | 1947-06-27 | 1951-05-08 | 0 | Details |
| US2552070A | Color television camera | Expired / Lapsed | 1947-06-02 | 1951-05-08 | 0 | Details |
| US2550753A | Erasing head for magnetic recorders | Expired / Lapsed | 1949-06-22 | 1951-05-01 | 0 | Details |
| US2551337A | Impedance measuring | Expired / Lapsed | 1948-07-29 | 1951-05-01 | 0 | Details |
| US2551228A | Tuning means for resonant transmission lines | Expired / Lapsed | 1946-05-31 | 1951-05-01 | 0 | Details |
| US2549641A | Display of three-dimensional information | Expired / Lapsed | 1947-10-31 | 1951-04-17 | 0 | Details |
| US2549585A | Multiple television projector | Expired / Lapsed | 1947-04-29 | 1951-04-17 | 0 | Details |
| US2549022A | Integrating counter circuit | Expired / Lapsed | 1945-10-27 | 1951-04-17 | 0 | Details |
| US2548118A | Art of analyzing optical images | Expired / Lapsed | 1950-05-01 | 1951-04-10 | 0 | Details |
| US2546926A | Electrical regulation system | Expired / Lapsed | 1948-12-30 | 1951-03-27 | 0 | Details |
| US2546837A | Paralleled amplifier circuits | Expired / Lapsed | 1947-08-21 | 1951-03-27 | 0 | Details |
| US2545957A | Color television pickup system | Expired / Lapsed | 1948-02-27 | 1951-03-20 | 0 | Details |
| US2545123A | Computing device | Expired / Lapsed | 1948-12-22 | 1951-03-13 | 0 | Details |
| US2545214A | Locking circuit and control | Expired / Lapsed | 1948-04-16 | 1951-03-13 | 0 | Details |
| US2545325A | Color television receiver | Expired / Lapsed | 1948-01-30 | 1951-03-13 | 0 | Details |
| US2545082A | Electronic switching device | Expired / Lapsed | 1946-05-28 | 1951-03-13 | 0 | Details |
| US2544211A | Variable impedance device | Expired / Lapsed | 1949-05-18 | 1951-03-06 | 0 | Details |
| US2543874A | Electronic distributor | Expired / Lapsed | 1946-09-25 | 1951-03-06 | 0 | Details |
| US2543719A | Deflection circuit | Expired / Lapsed | 1949-07-29 | 1951-02-27 | 0 | Details |
| US2543256A | Diversity receiver for multiplex frequency shift tones | Expired / Lapsed | 1948-05-20 | 1951-02-27 | 0 | Details |
| US2543738A | Time division pulse multiplex system | Expired / Lapsed | 1947-11-15 | 1951-02-27 | 0 | Details |
| US2543736A | Pulse multiplex system employing step-wave commutation | Expired / Lapsed | 1946-06-28 | 1951-02-27 | 0 | Details |
| US2542702A | Dielectric heat sealer | Expired / Lapsed | 1947-05-29 | 1951-02-20 | 0 | Details |
| US2542700A | Pulse modulation system | Expired / Lapsed | 1945-04-18 | 1951-02-20 | 0 | Details |
| US2541374A | Velocity-selection-type pickup tube | Expired / Lapsed | 1946-06-28 | 1951-02-13 | 0 | Details |
| US2540442A | Electronic counter | Expired / Lapsed | 1948-08-11 | 1951-02-06 | 0 | Details |
| US2540167A | Synchronizing system | Expired / Lapsed | 1948-04-21 | 1951-02-06 | 0 | Details |
| US2540623A | Method of forming dielectric coatings | Expired / Lapsed | 1947-03-12 | 1951-02-06 | 2 | Details |
| US2540551A | Electron trigger circuits | Expired / Lapsed | 1947-01-04 | 1951-02-06 | 0 | Details |
| US2540505A | Electronic frequency meter | Expired / Lapsed | 1946-04-18 | 1951-02-06 | 0 | Details |
| US2540524A | Electrical counter circuit | Expired / Lapsed | 1945-07-27 | 1951-02-06 | 0 | Details |
| US2539905A | Air navigation | Expired / Lapsed | 1946-12-21 | 1951-01-30 | 0 | Details |
| US2539673A | Frequency measuring system | Expired / Lapsed | 1944-04-20 | 1951-01-30 | 0 | Details |
| US2538547A | Facsimile synchronizing system | Expired / Lapsed | 1948-10-30 | 1951-01-16 | 0 | Details |
| US2538539A | Automatic tuning system | Expired / Lapsed | 1946-12-12 | 1951-01-16 | 0 | Details |
| US2538494A | Servo control amplifier | Expired / Lapsed | 1946-01-15 | 1951-01-16 | 0 | Details |
| US2537593A | Frequency modulation altimeter and range finder | Expired / Lapsed | 1947-02-26 | 1951-01-09 | 0 | Details |
| US2537569A | Time interval indicating system | Expired / Lapsed | 1947-02-15 | 1951-01-09 | 0 | Details |
| US2536838A | High-efficiency cathode-ray beam deflection system | Expired / Lapsed | 1949-05-24 | 1951-01-02 | 0 | Details |
| US2536255A | Radio carrier synchronization system | Expired / Lapsed | 1949-01-29 | 1951-01-02 | 0 | Details |
| US2536260A | Device for reproducing magnetic records | Expired / Lapsed | 1948-12-30 | 1951-01-02 | 0 | Details |
| US2536664A | Stereophonic sound system for recordings | Expired / Lapsed | 1945-09-10 | 1951-01-02 | 0 | Details |
| US2534387A | Morse code printing system | Expired / Lapsed | 1946-11-15 | 1950-12-19 | 0 | Details |
| US2534535A | Secrecy system | Expired / Lapsed | 1942-12-07 | 1950-12-19 | 0 | Details |
| US2533871A | Radio distance measuring system | Expired / Lapsed | 1944-06-16 | 1950-12-12 | 0 | Details |
| US2532843A | Pulse selective system | Expired / Lapsed | 1945-09-10 | 1950-12-05 | 0 | Details |
| US2531529A | Inspection apparatus and method | Expired / Lapsed | 1949-09-30 | 1950-11-28 | 0 | Details |
| US2532157A | Variable reactive microwave device | Expired / Lapsed | 1944-10-31 | 1950-11-28 | 0 | Details |
| US2531076A | Bistable semiconductor multivibrator circuit | Expired / Lapsed | 1949-10-22 | 1950-11-21 | 0 | Details |
| US2528512A | Energizing circuit for servo systems | Expired / Lapsed | 1945-09-29 | 1950-11-07 | 0 | Details |
| US2527967A | Multiplex transmission of television signals | Expired / Lapsed | 1947-11-12 | 1950-10-31 | 0 | Details |
| US2528119A | Frequency modulation range finder | Expired / Lapsed | 1947-04-25 | 1950-10-31 | 0 | Details |
| US2528202A | Radio navigation system | Expired / Lapsed | 1945-08-30 | 1950-10-31 | 0 | Details |
| US2527222A | Scanning antenna | Expired / Lapsed | 1947-10-30 | 1950-10-24 | 0 | Details |
| US2526353A | Stabilized low-frequency oscillator | Expired / Lapsed | 1946-11-15 | 1950-10-17 | 0 | Details |
| US2526207A | Capacitor for frequency modulation | Expired / Lapsed | 1946-04-27 | 1950-10-17 | 0 | Details |
| US2526000A | Frequency divider | Expired / Lapsed | 1945-05-26 | 1950-10-17 | 0 | Details |
| US2525102A | Television synchronizing signal generator | Expired / Lapsed | 1947-07-01 | 1950-10-10 | 0 | Details |
| US2525106A | Electronic keyer for direct current restoration | Expired / Lapsed | 1946-11-21 | 1950-10-10 | 0 | Details |
| US2525634A | Pulse communication system | Expired / Lapsed | 1945-12-07 | 1950-10-10 | 0 | Details |
| US2525356A | Apparatus for bonding material electrically | Expired / Lapsed | 1944-06-12 | 1950-10-10 | 0 | Details |
| US2524296A | Pulse-echo radio locator system | Expired / Lapsed | 1945-09-24 | 1950-10-03 | 0 | Details |
| US2524295A | Pulse-echo radio locator system | Expired / Lapsed | 1945-09-24 | 1950-10-03 | 0 | Details |
| US2524292A | Radio vision system with high-speed scanner for short radio… | Expired / Lapsed | 1944-04-18 | 1950-10-03 | 0 | Details |
| US2523363A | Method and apparatus for filling containers with a predeter… | Expired / Lapsed | 1945-01-26 | 1950-09-26 | 0 | Details |
| US2523244A | Navigation system with counter circuits for pulse timing an… | Expired / Lapsed | 1948-06-18 | 1950-09-19 | 0 | Details |
| US2522919A | Facsimile phasing system | Expired / Lapsed | 1948-01-27 | 1950-09-19 | 0 | Details |
| US2522969A | Automatic vacuum system | Expired / Lapsed | 1947-11-28 | 1950-09-19 | 0 | Details |
| US2522562A | Antenna system | Expired / Lapsed | 1945-04-21 | 1950-09-19 | 0 | Details |
| US2521774A | Predetermined counter | Expired / Lapsed | 1947-03-21 | 1950-09-12 | 0 | Details |
| US2521787A | Computing system | Expired / Lapsed | 1944-03-30 | 1950-09-12 | 0 | Details |
| US2520600A | Air traffic control | Expired / Lapsed | 1948-03-13 | 1950-08-29 | 0 | Details |
| US2520240A | Cathode-ray tube | Expired / Lapsed | 1946-09-05 | 1950-08-29 | 0 | Details |
| US2518843A | Aircraft antenna | Expired / Lapsed | 1947-04-25 | 1950-08-15 | 0 | Details |
| US2519172A | Control of electron discharge device of area selection type | Expired / Lapsed | 1946-08-30 | 1950-08-15 | 0 | Details |
| US2519173A | Regulating device | Expired / Lapsed | 1946-06-12 | 1950-08-15 | 0 | Details |
| US2517808A | Image recording and reproducing apparatus | Expired / Lapsed | 1948-12-22 | 1950-08-08 | 0 | Details |
| US2518200A | Television system | Expired / Lapsed | 1947-10-03 | 1950-08-08 | 0 | Details |
| US2517807A | Neutralization of deflection field between photocathode and… | Expired / Lapsed | 1945-05-30 | 1950-08-08 | 0 | Details |
| US2517404A | Scintillation type radiation detector and coincidence circu… | Expired / Lapsed | 1949-04-01 | 1950-08-01 | 0 | Details |
| US2517102A | Reading aid for the blind | Expired / Lapsed | 1946-11-29 | 1950-08-01 | 0 | Details |
| US2516324A | Constant potential gradient dielectric heating device | Expired / Lapsed | 1946-02-15 | 1950-07-25 | 0 | Details |
| US2516314A | Color television apparatus | Expired / Lapsed | 1945-07-07 | 1950-07-25 | 0 | Details |
| US2515677A | Direct current limiter and counter circuit | Expired / Lapsed | 1947-05-23 | 1950-07-18 | 0 | Details |
| US2515613A | Timer and synchronizing signal generator | Expired / Lapsed | 1946-07-11 | 1950-07-18 | 0 | Details |
| US2515668A | Gating circuit for diversity receivers | Expired / Lapsed | 1945-12-05 | 1950-07-18 | 0 | Details |
| US2515225A | Transceiver having switch controlled frequency compensator | Expired / Lapsed | 1944-12-30 | 1950-07-18 | 0 | Details |
| US2514367A | Fault locating for radio relay systems | Expired / Lapsed | 1946-09-12 | 1950-07-11 | 0 | Details |
| US2515055A | Diversity receiver | Expired / Lapsed | 1946-05-31 | 1950-07-11 | 0 | Details |
| US2515052A | Restoring device for locking circuits | Expired / Lapsed | 1946-04-04 | 1950-07-11 | 0 | Details |
| US2515030A | Wave generation and control | Expired / Lapsed | 1945-10-31 | 1950-07-11 | 0 | Details |
| US2514425A | Radio relaying | Expired / Lapsed | 1945-02-06 | 1950-07-11 | 0 | Details |
| US2513988A | Pulse echo altimeter with mechanically driven indicator | Expired / Lapsed | 1948-07-22 | 1950-07-04 | 0 | Details |
| US2514246A | Radio chassis of the plug-in type | Expired / Lapsed | 1947-09-30 | 1950-07-04 | 0 | Details |
| US2513490A | Selective communication system between ground station and a… | Expired / Lapsed | 1947-02-28 | 1950-07-04 | 0 | Details |
| US2513477A | Omnidirectional radio range | Expired / Lapsed | 1946-02-14 | 1950-07-04 | 0 | Details |
| US2512743A | Jet sprayer actuated by supersonic waves | Expired / Lapsed | 1946-04-01 | 1950-06-27 | 0 | Details |
| US2511981A | Electronic thermostat | Expired / Lapsed | 1947-09-26 | 1950-06-20 | 0 | Details |
| US2511216A | Process of making electrical resistors | Expired / Lapsed | 1946-08-01 | 1950-06-13 | 2 | Details |
| US2510397A | Heat-to-electrical energy converter | Expired / Lapsed | 1946-10-02 | 1950-06-06 | 0 | Details |
| US2510020A | Reflector for radar navigation | Expired / Lapsed | 1947-10-28 | 1950-05-30 | 0 | Details |
| US2509066A | Overmodulation communication system | Expired / Lapsed | 1948-05-28 | 1950-05-23 | 0 | Details |
| US2508853A | Radio relaying | Expired / Lapsed | 1945-04-12 | 1950-05-23 | 0 | Details |
| US2508082A | Remote control system for directcurrent motors | Expired / Lapsed | 1947-12-11 | 1950-05-16 | 0 | Details |
| US2507739A | Radio relaying | Expired / Lapsed | 1946-01-18 | 1950-05-16 | 0 | Details |
| US2507374A | Piezoelectric crystal holder | Expired / Lapsed | 1947-11-26 | 1950-05-09 | 0 | Details |
| US2506818A | Radio altimeter utilizing phase comparison | Expired / Lapsed | 1947-10-10 | 1950-05-09 | 0 | Details |
| US2507145A | Peak limiting expanding amplifier | Expired / Lapsed | 1947-07-02 | 1950-05-09 | 0 | Details |
| US2506770A | Wave shape correction circuit | Expired / Lapsed | 1946-01-30 | 1950-05-09 | 0 | Details |
| US2506741A | Television transmitting tube | Expired / Lapsed | 1945-11-28 | 1950-05-09 | 0 | Details |
| US2506127A | Optical mixing of plan position indication and graphical in… | Expired / Lapsed | 1948-04-30 | 1950-05-02 | 0 | Details |
| US2505629A | Method of depositing silica films and preparation of soluti… | Expired / Lapsed | 1949-06-30 | 1950-04-25 | 2 | Details |
| US2503700A | Phase detector | Expired / Lapsed | 1947-09-30 | 1950-04-11 | 0 | Details |
| US2503957A | Diversity receiver system | Expired / Lapsed | 1945-02-20 | 1950-04-11 | 0 | Details |
| US2501327A | Noise operated automatic volume control | Expired / Lapsed | 1946-12-06 | 1950-03-21 | 0 | Details |
| US2501120A | Frequency modulation receiver tuning aid | Expired / Lapsed | 1945-04-26 | 1950-03-21 | 0 | Details |
| US2500545A | Air traffic control | Expired / Lapsed | 1947-11-20 | 1950-03-14 | 0 | Details |
| US2500581A | Frequency divider | Expired / Lapsed | 1945-10-25 | 1950-03-14 | 0 | Details |
| US2499484A | Voltage rectifying circuit | Expired / Lapsed | 1945-11-28 | 1950-03-07 | 0 | Details |
| US2499603A | Rerecording method and system | Expired / Lapsed | 1945-10-23 | 1950-03-07 | 0 | Details |
| US2499225A | Data transmission system | Expired / Lapsed | 1947-11-26 | 1950-02-28 | 0 | Details |
| US2499234A | Pulse forming circuit | Expired / Lapsed | 1944-12-28 | 1950-02-28 | 0 | Details |
| US2497936A | Code printer | Expired / Lapsed | 1946-10-18 | 1950-02-21 | 0 | Details |
| US2496912A | Device for integrating a variable quantity | Expired / Lapsed | 1946-05-09 | 1950-02-07 | 0 | Details |
| US2496994A | Frequency dividing network | Expired / Lapsed | 1945-12-22 | 1950-02-07 | 0 | Details |
| US2496063A | Automatic tuning circuit for radio receivers | Expired / Lapsed | 1948-07-23 | 1950-01-31 | 0 | Details |
| US2496047A | Art of recording and reproducing two-sided magnetic records | Expired / Lapsed | 1947-06-18 | 1950-01-31 | 0 | Details |
| US2494441A | Method and apparatus for electronically determining particl… | Expired / Lapsed | 1948-07-28 | 1950-01-10 | 0 | Details |
| US2494309A | Diversity receiver | Expired / Lapsed | 1945-11-17 | 1950-01-10 | 0 | Details |
| US2493627A | Electronic time measuring device | Expired / Lapsed | 1946-05-01 | 1950-01-03 | 0 | Details |
| US2493446A | Radio receiver noise muting circuit | Expired / Lapsed | 1946-01-23 | 1950-01-03 | 0 | Details |
| US2492779A | Servo controller | Expired / Lapsed | 1946-03-26 | 1949-12-27 | 0 | Details |
| US2491387A | Frequency shift keying | Expired / Lapsed | 1945-05-03 | 1949-12-13 | 0 | Details |
| US2491450A | Radio pulse-echo locator system to distinguish between movi… | Expired / Lapsed | 1944-02-24 | 1949-12-13 | 0 | Details |
| US2490499A | Variable frequency oscillation generator | Expired / Lapsed | 1947-04-23 | 1949-12-06 | 0 | Details |
| US2490404A | Stabilized oscillation generator | Expired / Lapsed | 1947-01-07 | 1949-12-06 | 0 | Details |
| US2490500A | Stabilized oscillator generator | Expired / Lapsed | 1946-12-28 | 1949-12-06 | 0 | Details |
| US2490662A | Skeletonizing glass | Expired / Lapsed | 1946-09-21 | 1949-12-06 | 0 | Details |
| US2490627A | Photoelectric liquid level indicator | Expired / Lapsed | 1945-06-30 | 1949-12-06 | 0 | Details |
| US2489689A | Servo system with eddy current brake controlled by error vo… | Expired / Lapsed | 1946-12-14 | 1949-11-29 | 0 | Details |
| US2489813A | Transmitter apparatus | Expired / Lapsed | 1945-07-26 | 1949-11-29 | 0 | Details |
| US2489824A | Square wave generator with impulse counter timing control f… | Expired / Lapsed | 1943-12-24 | 1949-11-29 | 0 | Details |
| US2489127A | High capacitance target | Expired / Lapsed | 1947-06-14 | 1949-11-22 | 0 | Details |
| US2488927A | Variable bridge transducer and its combination with a radio… | Expired / Lapsed | 1945-03-10 | 1949-11-22 | 0 | Details |
| US2488022A | Radio receiving and indicating system | Expired / Lapsed | 1945-02-01 | 1949-11-15 | 0 | Details |
| US2488419A | Antenna and lobe switcher | Expired / Lapsed | 1943-06-30 | 1949-11-15 | 0 | Details |
| US2487656A | Electron discharge device of the beam deflection type | Expired / Lapsed | 1943-11-22 | 1949-11-08 | 0 | Details |
| US2487513A | Radio relaying system | Expired / Lapsed | 1943-10-26 | 1949-11-08 | 0 | Details |
| US2485825A | Computing circuits | Expired / Lapsed | 1944-01-18 | 1949-10-25 | 0 | Details |
| US2485045A | Piezoelectric oscillator | Expired / Lapsed | 1947-05-29 | 1949-10-18 | 0 | Details |
| US2482329A | Apparatus for selective vapor coating | Expired / Lapsed | 1946-05-27 | 1949-09-20 | 0 | Details |
| US2481839A | Color television | Expired / Lapsed | 1944-08-05 | 1949-09-13 | 0 | Details |
| US2481410A | Radio guiding system | Expired / Lapsed | 1942-12-29 | 1949-09-06 | 0 | Details |
| US2480386A | Transcriber for ink recorder tape | Expired / Lapsed | 1947-04-09 | 1949-08-30 | 0 | Details |
| US2480511A | Scanning circuit | Expired / Lapsed | 1944-09-29 | 1949-08-30 | 0 | Details |
| US2480068A | Radio navigation aid | Expired / Lapsed | 1946-08-09 | 1949-08-23 | 0 | Details |
| US2479673A | Directional microwave transmission system having dielectric… | Expired / Lapsed | 1945-08-20 | 1949-08-23 | 0 | Details |
| US2479548A | Control circuit | Expired / Lapsed | 1945-03-15 | 1949-08-16 | 0 | Details |
| US2478920A | Pulse system | Expired / Lapsed | 1943-08-04 | 1949-08-16 | 0 | Details |
| US2478919A | Pulse type multiplex communication system | Expired / Lapsed | 1943-07-17 | 1949-08-16 | 0 | Details |
| US2478857A | Radio-frequency heating | Expired / Lapsed | 1945-12-22 | 1949-08-09 | 0 | Details |
| US2478679A | Projector drive mechanism | Expired / Lapsed | 1945-10-23 | 1949-08-09 | 0 | Details |
| US2477475A | Adjustable coupling transformer | Expired / Lapsed | 1949-04-01 | 1949-07-26 | 0 | Details |
| US2477214A | Electrode structure for high-frequency sealing of thin ther… | Expired / Lapsed | 1948-01-31 | 1949-07-26 | 0 | Details |
| US2477050A | Submarine attacking device | Expired / Lapsed | 1946-03-06 | 1949-07-26 | 0 | Details |
| US2477040A | Sewing machine for thermoplastic materials | Expired / Lapsed | 1945-03-13 | 1949-07-26 | 0 | Details |
| US2477122A | Electron discharge device | Expired / Lapsed | 1942-05-30 | 1949-07-26 | 0 | Details |
| US2476167A | Electrical protection of cathoderay tube screens | Expired / Lapsed | 1948-05-01 | 1949-07-12 | 0 | Details |
| US2475212A | Aircraft instrument indicator | Expired / Lapsed | 1947-05-23 | 1949-07-05 | 0 | Details |
| US2475200A | Signal recording apparatus | Expired / Lapsed | 1945-06-28 | 1949-07-05 | 0 | Details |
| US2475050A | Constant current circuit | Expired / Lapsed | 1945-06-20 | 1949-07-05 | 0 | Details |
| US2474098A | Photometric measurement of light values using automatic gai… | Expired / Lapsed | 1946-03-29 | 1949-06-21 | 0 | Details |
| US2474040A | Pulse integrating circuits | Expired / Lapsed | 1945-11-16 | 1949-06-21 | 0 | Details |
| US2473344A | Overload protection system | Expired / Lapsed | 1945-01-26 | 1949-06-14 | 0 | Details |
| US2473188A | Radio-frequency dielectric heater with constant heating rat… | Expired / Lapsed | 1944-06-17 | 1949-06-14 | 0 | Details |
| US2473444A | Computing system | Expired / Lapsed | 1944-02-29 | 1949-06-14 | 0 | Details |
| US2472167A | Frequency sensitive circuit | Expired / Lapsed | 1945-03-13 | 1949-06-07 | 0 | Details |
| US2472301A | Frequency modulated-amplitude modulated receiver | Expired / Lapsed | 1945-03-02 | 1949-06-07 | 0 | Details |
| US2471788A | Electronic computer | Expired / Lapsed | 1947-02-15 | 1949-05-31 | 0 | Details |
| US2470912A | Navigation aiding apparatus | Expired / Lapsed | 1947-11-28 | 1949-05-24 | 0 | Details |
| US2470875A | Storage tube | Expired / Lapsed | 1946-04-12 | 1949-05-24 | 0 | Details |
| US2470939A | Radio detection and location system indicating azimuth and … | Expired / Lapsed | 1943-09-03 | 1949-05-24 | 0 | Details |
| US2470240A | Limiting detector circuits | Expired / Lapsed | 1945-07-31 | 1949-05-17 | 0 | Details |
| US2470303A | Computer | Expired / Lapsed | 1944-03-30 | 1949-05-17 | 0 | Details |
| US2469444A | Magnetic sound recording and reproducing transducer | Expired / Lapsed | 1945-04-30 | 1949-05-10 | 0 | Details |
| US2469227A | Electronic wave generating method and means | Expired / Lapsed | 1946-01-30 | 1949-05-03 | 0 | Details |
| US2468197A | Transmitter tuning indicator | Expired / Lapsed | 1946-12-12 | 1949-04-26 | 0 | Details |
| US2467777A | Frequency measuring circuit | Expired / Lapsed | 1942-04-01 | 1949-04-19 | 0 | Details |
| US2467670A | Radio pulse echo system using doppler effect | Expired / Lapsed | 1939-07-28 | 1949-04-19 | 0 | Details |
| US2466784A | Cathode-ray beam deflecting circuit | Expired / Lapsed | 1945-01-13 | 1949-04-12 | 0 | Details |
| US2466534A | Radar glide path control system | Expired / Lapsed | 1945-07-30 | 1949-04-05 | 0 | Details |
| US2465925A | Radio control system | Expired / Lapsed | 1944-05-18 | 1949-03-29 | 0 | Details |
| US2464848A | Fuse indicating system | Expired / Lapsed | 1947-01-03 | 1949-03-22 | 0 | Details |
| US2465102A | Radio-frequency heating apparatus | Expired / Lapsed | 1943-10-04 | 1949-03-22 | 0 | Details |
| US2464404A | Apparatus for heating dielectric materials electronically | Expired / Lapsed | 1945-09-28 | 1949-03-15 | 0 | Details |
| US2464353A | Electronic switching system | Expired / Lapsed | 1943-09-16 | 1949-03-15 | 0 | Details |
| US2463685A | Automatic frequency control system | Expired / Lapsed | 1944-07-31 | 1949-03-08 | 0 | Details |
| US2463073A | Oscillator | Expired / Lapsed | 1945-01-26 | 1949-03-01 | 0 | Details |
| US2462569A | Television receiving tube with storage properties | Expired / Lapsed | 1946-09-11 | 1949-02-22 | 0 | Details |
| US2462294A | Automatic frequency control | Expired / Lapsed | 1946-05-22 | 1949-02-22 | 0 | Details |
| US2462555A | Copolymers of styrene and 4,4'-divinyl-biphenyl | Expired / Lapsed | 1945-11-24 | 1949-02-22 | 0 | Details |
| US2462456A | Antihunt servomotor control system | Expired / Lapsed | 1945-04-14 | 1949-02-22 | 0 | Details |
| US2462263A | Reproduction of sound | Expired / Lapsed | 1945-02-02 | 1949-02-22 | 0 | Details |
| US2462292A | Light interference distance measuring device having photoel… | Expired / Lapsed | 1943-08-13 | 1949-02-22 | 0 | Details |
| US2460869A | Antenna | Expired / Lapsed | 1946-03-14 | 1949-02-08 | 0 | Details |
| US2460789A | Fault indicator for radio relaying systems | Expired / Lapsed | 1946-03-15 | 1949-02-01 | 0 | Details |
| US2460471A | Method and apparatus for measuring persistence screen chara… | Expired / Lapsed | 1945-12-07 | 1949-02-01 | 0 | Details |
| US2460781A | Circuit for stabilizing frequencies of transmitter-receiver… | Expired / Lapsed | 1945-02-27 | 1949-02-01 | 0 | Details |
| US2459632A | Comparison control system | Expired / Lapsed | 1947-12-26 | 1949-01-18 | 0 | Details |
| US2459481A | Instrument landing system | Expired / Lapsed | 1945-10-18 | 1949-01-18 | 0 | Details |
| US2459461A | Frequency modulation distance indicator | Expired / Lapsed | 1945-06-23 | 1949-01-18 | 0 | Details |
| US2459457A | Comparator circuits for radio locators | Expired / Lapsed | 1944-03-20 | 1949-01-18 | 0 | Details |
| US2459131A | Electronic distributor for multiplex pulse communication sy… | Expired / Lapsed | 1946-09-24 | 1949-01-11 | 0 | Details |
| US2458641A | Method and apparatus for controlling frequency characterist… | Expired / Lapsed | 1945-05-08 | 1949-01-11 | 0 | Details |
| US2458649A | Color television | Expired / Lapsed | 1941-01-31 | 1949-01-11 | 0 | Details |
| US2457974A | Pulse type telegraph receiver | Expired / Lapsed | 1943-06-17 | 1949-01-04 | 0 | Details |
| US2457456A | Reading aid for the blind | Expired / Lapsed | 1946-05-14 | 1948-12-28 | 0 | Details |
| US2457288A | Frequency shift keying | Expired / Lapsed | 1946-02-07 | 1948-12-28 | 0 | Details |
| US2457013A | Angle modulated wave discriminator | Expired / Lapsed | 1944-07-28 | 1948-12-21 | 0 | Details |
| US2456026A | Modulator employing trigger circuit | Expired / Lapsed | 1947-06-14 | 1948-12-14 | 0 | Details |
| US2455974A | Automatic solution of linear simultaneous equations | Expired / Lapsed | 1946-11-15 | 1948-12-14 | 0 | Details |
| US2456089A | Wide band frequency modulator | Expired / Lapsed | 1946-06-26 | 1948-12-14 | 0 | Details |
| US2455456A | Three-dimensional oscillograph system | Expired / Lapsed | 1948-02-20 | 1948-12-07 | 0 | Details |
| US2455443A | Secret radio signaling system | Expired / Lapsed | 1945-10-12 | 1948-12-07 | 0 | Details |
| US2455693A | Distance determining system | Expired / Lapsed | 1945-07-26 | 1948-12-07 | 0 | Details |
| US2455476A | Mounting system for elements of television projectors | Expired / Lapsed | 1945-07-20 | 1948-12-07 | 0 | Details |
| US2455646A | Phase responsive control circuit | Expired / Lapsed | 1944-12-30 | 1948-12-07 | 0 | Details |
| US2455711A | Bidirectional high gain amplifier | Expired / Lapsed | 1944-12-23 | 1948-12-07 | 0 | Details |
| US2455639A | Ground speed indicator utilizing doppler effect | Expired / Lapsed | 1943-10-26 | 1948-12-07 | 0 | Details |
| US2455673A | Distance selective system | Expired / Lapsed | 1942-01-19 | 1948-12-07 | 0 | Details |
| US2455323A | Phasing system | Expired / Lapsed | 1946-06-22 | 1948-11-30 | 0 | Details |
| US2455136A | Method of securing leads to electrical capacitors | Expired / Lapsed | 1943-12-31 | 1948-11-30 | 0 | Details |
| US2454673A | Radio bomb release system | Expired / Lapsed | 1944-03-02 | 1948-11-23 | 0 | Details |
| US2454652A | Cathode-ray storage tube | Expired / Lapsed | 1943-06-26 | 1948-11-23 | 0 | Details |
| US2453970A | Recognition system for pulse echo radio locators | Expired / Lapsed | 1941-05-31 | 1948-11-16 | 0 | Details |
| US2453532A | Electrostatic microwave energy measuring apparatus | Expired / Lapsed | 1945-06-11 | 1948-11-09 | 0 | Details |
| US2453414A | System for directing radio waves | Expired / Lapsed | 1944-06-09 | 1948-11-09 | 0 | Details |
| US2452620A | Electrode support in television tubes | Expired / Lapsed | 1946-11-14 | 1948-11-02 | 0 | Details |
| US2452619A | Cathode-ray tube | Expired / Lapsed | 1946-02-07 | 1948-11-02 | 0 | Details |
| US2452013A | Power supply | Expired / Lapsed | 1945-11-29 | 1948-10-19 | 0 | Details |
| US2449969A | Compensating device | Expired / Lapsed | 1945-05-29 | 1948-09-28 | 0 | Details |
| US2450360A | Timing marker and station selection apparatus | Expired / Lapsed | 1944-08-31 | 1948-09-28 | 0 | Details |
| US2449819A | Multiplex radio communication | Expired / Lapsed | 1944-05-29 | 1948-09-21 | 0 | Details |
| US2449923A | Timing modulation system | Expired / Lapsed | 1943-03-19 | 1948-09-21 | 0 | Details |
| US2449339A | Cathode-ray tube | Expired / Lapsed | 1945-11-13 | 1948-09-14 | 0 | Details |
| US2449078A | Commutator apparatus | Expired / Lapsed | 1943-03-15 | 1948-09-14 | 0 | Details |
| US2448527A | Cold cathode electron discharge device and circuits therefor | Expired / Lapsed | 1944-09-08 | 1948-09-07 | 0 | Details |
| US2447057A | Diversity receiving system | Expired / Lapsed | 1943-05-06 | 1948-08-17 | 0 | Details |
| US2446791A | Color television tube | Expired / Lapsed | 1946-06-11 | 1948-08-10 | 0 | Details |
| US2446440A | Color television tube | Expired / Lapsed | 1947-01-28 | 1948-08-03 | 0 | Details |
| US2446249A | Pickup tube for color television | Expired / Lapsed | 1946-05-04 | 1948-08-03 | 0 | Details |
| US2446244A | Pulse-echo system | Expired / Lapsed | 1943-05-22 | 1948-08-03 | 0 | Details |
| US2446279A | Aerial bomb control system | Expired / Lapsed | 1942-09-19 | 1948-08-03 | 0 | Details |
| US2445962A | Method of forming silver sulfide coatings | Expired / Lapsed | 1944-08-24 | 1948-07-27 | 0 | Details |
| US2445361A | Radio navigation system | Expired / Lapsed | 1945-04-20 | 1948-07-20 | 0 | Details |
| US2445448A | Electron discharge device trigger circuit | Expired / Lapsed | 1944-07-27 | 1948-07-20 | 0 | Details |
| US2445215A | Electronic computer | Expired / Lapsed | 1943-10-21 | 1948-07-13 | 0 | Details |
| US2445040A | Dark spot corrector | Expired / Lapsed | 1943-05-13 | 1948-07-13 | 0 | Details |
| US2445213A | Obstacle detector | Expired / Lapsed | 1941-04-30 | 1948-07-13 | 0 | Details |
| US2444479A | Frequency-modulated pulse generator | Expired / Lapsed | 1944-01-08 | 1948-07-06 | 0 | Details |
| US2444312A | Art of sealing metal casings enclosing vibratile elements | Expired / Lapsed | 1945-05-01 | 1948-06-29 | 0 | Details |
| US2444171A | Aircraft navigation | Expired / Lapsed | 1944-07-26 | 1948-06-29 | 0 | Details |
| US2444084A | Resistance-capacitance oscillator | Expired / Lapsed | 1943-06-21 | 1948-06-29 | 0 | Details |
| US2443718A | Direction finder | Expired / Lapsed | 1945-03-28 | 1948-06-22 | 0 | Details |
| US2443746A | Tube reactance and modulator | Expired / Lapsed | 1943-12-01 | 1948-06-22 | 0 | Details |
| US2443258A | Optical signaling system, including means for dispersing an… | Expired / Lapsed | 1942-04-30 | 1948-06-15 | 0 | Details |
| US2443094A | Frequency multiplier network | Expired / Lapsed | 1946-12-18 | 1948-06-08 | 0 | Details |
| US2442951A | System for focusing and for directing radio-frequency energy | Expired / Lapsed | 1944-05-27 | 1948-06-08 | 0 | Details |
| US2443098A | Apparatus for determining the weight and center of gravity … | Expired / Lapsed | 1944-02-28 | 1948-06-08 | 0 | Details |
| US2442968A | Apparatus for simultaneously induction heating a plurality … | Expired / Lapsed | 1943-06-30 | 1948-06-08 | 0 | Details |
| US2442692A | Radio navigation system | Expired / Lapsed | 1946-07-10 | 1948-06-01 | 0 | Details |
| US2442606A | Phase indicating reflectometer | Expired / Lapsed | 1945-12-28 | 1948-06-01 | 0 | Details |
| US2442451A | High-frequency dielectric heating apparatus | Expired / Lapsed | 1944-10-26 | 1948-06-01 | 0 | Details |
| US2442583A | Scanning receiving system | Expired / Lapsed | 1942-10-10 | 1948-06-01 | 0 | Details |
| US2442403A | Electronic switching and computing device | Expired / Lapsed | 1942-09-23 | 1948-06-01 | 0 | Details |
| US2441661A | Diversity combiner | Expired / Lapsed | 1943-04-20 | 1948-05-18 | 0 | Details |
| US2441296A | Computer system | Expired / Lapsed | 1943-12-27 | 1948-05-11 | 0 | Details |
| US2441006A | Electronic locking circuit | Expired / Lapsed | 1945-06-28 | 1948-05-04 | 0 | Details |
| US2440600A | Electric motor control | Expired / Lapsed | 1942-11-18 | 1948-04-27 | 0 | Details |
| US2440118A | Indicator control mechanism | Expired / Lapsed | 1946-01-12 | 1948-04-20 | 0 | Details |
| US2440189A | Convection current responsive instrument | Expired / Lapsed | 1945-04-13 | 1948-04-20 | 0 | Details |
| US2439665A | Sound reproducing device | Expired / Lapsed | 1944-01-31 | 1948-04-13 | 0 | Details |
| US2439223A | Rectifier system | Expired / Lapsed | 1945-02-19 | 1948-04-06 | 0 | Details |
| US2438588A | System for comparison or analysis of information | Expired / Lapsed | 1946-09-14 | 1948-03-30 | 0 | Details |
| US2437313A | Electrical servo system | Expired / Lapsed | 1944-12-30 | 1948-03-09 | 0 | Details |
| US2436963A | Electronic counting chain with decimal indicators | Expired / Lapsed | 1944-02-26 | 1948-03-02 | 0 | Details |
| US2437085A | Heat detection device | Expired / Lapsed | 1943-03-12 | 1948-03-02 | 0 | Details |
| US2436178A | Electronic computer for transforming polar into rectilinear… | Expired / Lapsed | 1943-10-21 | 1948-02-17 | 0 | Details |
| US2435841A | Computing device | Expired / Lapsed | 1944-01-05 | 1948-02-10 | 0 | Details |
| US2435804A | Cavity resonator magnetron device | Expired / Lapsed | 1944-01-01 | 1948-02-10 | 0 | Details |
| US2435840A | Computing device | Expired / Lapsed | 1943-12-28 | 1948-02-10 | 0 | Details |
| US2435519A | Image-forming heat detector | Expired / Lapsed | 1944-02-14 | 1948-02-03 | 0 | Details |
| US2435170A | Apparatus for molding plastic articles | Expired / Lapsed | 1946-04-01 | 1948-01-27 | 0 | Details |
| US2434813A | Aircraft navigation | Expired / Lapsed | 1944-07-29 | 1948-01-20 | 0 | Details |
| US2433941A | Television transmitting tube | Expired / Lapsed | 1944-09-16 | 1948-01-06 | 0 | Details |
| US2434155A | Electronically controlled variable gain amplifier | Expired / Lapsed | 1943-09-27 | 1948-01-06 | 0 | Details |
| US2433804A | Frequency-modulated pulse radio locating system | Expired / Lapsed | 1943-04-23 | 1947-12-30 | 0 | Details |
| US2433290A | Two-way radio communication system | Expired / Lapsed | 1945-03-23 | 1947-12-23 | 0 | Details |
| US2433284A | Radio bomb release system | Expired / Lapsed | 1944-10-02 | 1947-12-23 | 0 | Details |
| US2432939A | Radio navigation system | Expired / Lapsed | 1944-05-04 | 1947-12-16 | 0 | Details |
| US2432908A | Cathode-ray target and method of manufacture | Expired / Lapsed | 1942-07-22 | 1947-12-16 | 0 | Details |
| US2432158A | Radio navigation system | Expired / Lapsed | 1944-12-14 | 1947-12-09 | 0 | Details |
| US2432188A | Telegraph secrecy system | Expired / Lapsed | 1944-06-22 | 1947-12-09 | 0 | Details |
| US2432173A | Radar direction indicator | Expired / Lapsed | 1944-05-20 | 1947-12-09 | 0 | Details |
| US2432204A | Pulse modulation system | Expired / Lapsed | 1944-01-05 | 1947-12-09 | 0 | Details |
| US2432214A | Electrical wave analyzer | Expired / Lapsed | 1943-09-25 | 1947-12-09 | 0 | Details |
| US2432292A | Electronic counter circuit | Expired / Lapsed | 1943-05-29 | 1947-12-09 | 0 | Details |
| US2431766A | Modified sweep circuit for cathode-ray tubes | Expired / Lapsed | 1943-09-10 | 1947-12-02 | 0 | Details |
| US2431923A | Photographic record and method of forming same | Expired / Lapsed | 1943-08-23 | 1947-12-02 | 0 | Details |
| US2431651A | Tape printer | Expired / Lapsed | 1943-08-28 | 1947-11-25 | 0 | Details |
| US2431591A | Electronic computer | Expired / Lapsed | 1942-03-31 | 1947-11-25 | 0 | Details |
| US2430994A | Method of coating lenses | Expired / Lapsed | 1944-07-29 | 1947-11-18 | 0 | Details |
| US2431167A | Radio alarm and two-way telephone system | Expired / Lapsed | 1944-02-03 | 1947-11-18 | 0 | Details |
| US2430725A | Triggering system for obtaining a sharp-sided output pulse … | Expired / Lapsed | 1943-11-12 | 1947-11-11 | 0 | Details |
| US2430547A | Start-stop electronic regenerative telegraph signal repeater | Expired / Lapsed | 1943-10-28 | 1947-11-11 | 0 | Details |
| US2430283A | Radio distance and direction recorder | Expired / Lapsed | 1945-04-13 | 1947-11-04 | 0 | Details |
| US2430139A | Pulse number modulation system | Expired / Lapsed | 1944-01-08 | 1947-11-04 | 0 | Details |
| US2430307A | Recorder for radar systems | Expired / Lapsed | 1943-08-30 | 1947-11-04 | 0 | Details |
| US2430154A | Oscillograph timing circuit | Expired / Lapsed | 1943-06-26 | 1947-11-04 | 0 | Details |
| US2430292A | Radio air navigation indicator | Expired / Lapsed | 1942-11-02 | 1947-11-04 | 0 | Details |
| US2430013A | Impedance matching means for mechanical waves | Expired / Lapsed | 1942-06-10 | 1947-11-04 | 0 | Details |
| US2429849A | Color television system | Expired / Lapsed | 1945-09-15 | 1947-10-28 | 0 | Details |
| US2429747A | Combined frequency divider and detector | Expired / Lapsed | 1945-01-19 | 1947-10-28 | 0 | Details |
| US2429771A | Frequency responsive remotecontrol system | Expired / Lapsed | 1942-09-26 | 1947-10-28 | 0 | Details |
| US2429228A | Electronic computer | Expired / Lapsed | 1945-06-11 | 1947-10-21 | 0 | Details |
| US2429227A | Electronic computing system | Expired / Lapsed | 1945-06-11 | 1947-10-21 | 0 | Details |
| US2428946A | Synchronizing in color television | Expired / Lapsed | 1944-10-19 | 1947-10-14 | 0 | Details |
| US2428868A | Apparatus for producing hardened optical coatings by electr… | Expired / Lapsed | 1944-05-01 | 1947-10-14 | 0 | Details |
| US2428913A | Count selector | Expired / Lapsed | 1943-12-10 | 1947-10-14 | 0 | Details |
| US2428812A | Electronic computing device | Expired / Lapsed | 1943-11-25 | 1947-10-14 | 0 | Details |
| US2428811A | Electronic computing device | Expired / Lapsed | 1943-10-30 | 1947-10-14 | 0 | Details |
| US2428990A | Electronic computer | Expired / Lapsed | 1943-01-22 | 1947-10-14 | 0 | Details |
| US2428424A | Pulse-echo altimeter | Expired / Lapsed | 1945-05-30 | 1947-10-07 | 0 | Details |
| US2428272A | Transmission line transducer | Expired / Lapsed | 1944-11-08 | 1947-09-30 | 0 | Details |
| US2427850A | Switching method and system | Expired / Lapsed | 1945-03-17 | 1947-09-23 | 0 | Details |
| US2427872A | Tapered magnetic core | Expired / Lapsed | 1943-03-24 | 1947-09-23 | 0 | Details |
| US2427597A | Method of exhausting and cold weld sealing | Expired / Lapsed | 1941-11-01 | 1947-09-16 | 0 | Details |
| US2427319A | Beverage inspection machine | Expired / Lapsed | 1945-01-12 | 1947-09-09 | 0 | Details |
| US2427100A | Microwave variable reactances | Expired / Lapsed | 1943-10-26 | 1947-09-09 | 0 | Details |
| US2427094A | Super-high-frequency wattmeter | Expired / Lapsed | 1943-08-31 | 1947-09-09 | 0 | Details |
| US2427220A | Radio position indicating system | Expired / Lapsed | 1942-11-14 | 1947-09-09 | 0 | Details |
| US2426910A | Measurement of time between pulses | Expired / Lapsed | 1944-01-27 | 1947-09-02 | 0 | Details |
| US2426355A | Bottle inspection apparatus | Expired / Lapsed | 1944-09-27 | 1947-08-26 | 0 | Details |
| US2426494A | Heat detection device | Expired / Lapsed | 1943-12-20 | 1947-08-26 | 0 | Details |
| US2426193A | Radio transmitter automatic volume control | Expired / Lapsed | 1943-06-17 | 1947-08-26 | 0 | Details |
| US2425924A | Phase modulation detector | Expired / Lapsed | 1945-03-19 | 1947-08-19 | 0 | Details |
| US2425315A | Pulse communication system | Expired / Lapsed | 1944-02-17 | 1947-08-12 | 0 | Details |
| US2425495A | Two-way telephone system | Expired / Lapsed | 1943-10-30 | 1947-08-12 | 0 | Details |
| US2425379A | Transmission line circuit | Expired / Lapsed | 1943-09-04 | 1947-08-12 | 0 | Details |
| US2425488A | Horn antenna | Expired / Lapsed | 1943-07-03 | 1947-08-12 | 0 | Details |
| US2425405A | Electronic computing circuit | Expired / Lapsed | 1942-08-29 | 1947-08-12 | 0 | Details |
| US2425063A | Telegraphic keying bias adjuster | Expired / Lapsed | 1945-02-10 | 1947-08-05 | 0 | Details |
| US2425131A | Electronic computing circuit | Expired / Lapsed | 1945-01-29 | 1947-08-05 | 0 | Details |
| US2424833A | Frequency comparison and control circuit | Expired / Lapsed | 1944-10-18 | 1947-07-29 | 0 | Details |
| US2424905A | Automatic amplitude control for variable frequency oscillat… | Expired / Lapsed | 1943-08-10 | 1947-07-29 | 0 | Details |
| US2424886A | Magnetron | Expired / Lapsed | 1942-12-29 | 1947-07-29 | 0 | Details |
| US2424854A | Pulsed frequency modulated altimeter | Expired / Lapsed | 1942-08-29 | 1947-07-29 | 0 | Details |
| US2424312A | Average value voltage measuring device | Expired / Lapsed | 1946-04-25 | 1947-07-22 | 0 | Details |
| US2424274A | Pulse receiving system | Expired / Lapsed | 1945-08-30 | 1947-07-22 | 0 | Details |
| US2423870A | Composite sheet metal structure | Expired / Lapsed | 1941-03-26 | 1947-07-15 | 0 | Details |
| US2423770A | Color television system | Expired / Lapsed | 1945-04-07 | 1947-07-08 | 0 | Details |
| US2423523A | Pulse direction finder system | Expired / Lapsed | 1943-12-30 | 1947-07-08 | 0 | Details |
| US2423648A | Antenna | Expired / Lapsed | 1943-01-27 | 1947-07-08 | 0 | Details |
| US2423769A | Color television system | Expired / Lapsed | 1942-08-21 | 1947-07-08 | 0 | Details |
| US2423671A | Apparatus for and method of pulse limitation and amplificat… | Expired / Lapsed | 1940-01-29 | 1947-07-08 | 0 | Details |
| US2423644A | Range finder | Expired / Lapsed | 1939-05-19 | 1947-07-08 | 0 | Details |
| US2423383A | Absorptive gas microwave measuring system | Expired / Lapsed | 1945-02-13 | 1947-07-01 | 0 | Details |
| US2423254A | Frequency modulation light beam transmission | Expired / Lapsed | 1944-08-25 | 1947-07-01 | 0 | Details |
| US2423339A | Reproducing head for magnetic telegraphones | Expired / Lapsed | 1944-07-29 | 1947-07-01 | 0 | Details |
| US2423416A | Nonfrequency-selective reflectometer | Expired / Lapsed | 1944-03-30 | 1947-07-01 | 0 | Details |
| US2422971A | Heat responsive indicator | Expired / Lapsed | 1942-12-29 | 1947-06-24 | 0 | Details |
| US2423023A | Obstacle detection by radio waves | Expired / Lapsed | 1938-09-30 | 1947-06-24 | 0 | Details |
| US2422386A | Frequency measurement | Expired / Lapsed | 1943-11-22 | 1947-06-17 | 0 | Details |
| US2422295A | Recorder for radio locators | Expired / Lapsed | 1943-08-30 | 1947-06-17 | 0 | Details |
| US2422361A | Electronic indicator system | Expired / Lapsed | 1943-01-28 | 1947-06-17 | 0 | Details |
| US2422334A | Automatic gain control for pulseecho systems | Expired / Lapsed | 1943-01-23 | 1947-06-17 | 0 | Details |
| US2422333A | Pulse-echo control system | Expired / Lapsed | 1942-10-19 | 1947-06-17 | 0 | Details |
| US2422088A | Electronic discriminator | Expired / Lapsed | 1944-04-03 | 1947-06-10 | 0 | Details |
| US2422064A | Ground speed indicator | Expired / Lapsed | 1943-10-26 | 1947-06-10 | 0 | Details |
| US2422076A | Antenna system | Expired / Lapsed | 1943-07-28 | 1947-06-10 | 0 | Details |
| US2422135A | Frequency modulated distance indicator | Expired / Lapsed | 1943-06-26 | 1947-06-10 | 0 | Details |
| US2422140A | Frequency modulated recording and reproducing system | Expired / Lapsed | 1943-05-15 | 1947-06-10 | 0 | Details |
| US2422134A | Distance indicator | Expired / Lapsed | 1943-03-29 | 1947-06-10 | 0 | Details |
| US2422072A | Radio compass | Expired / Lapsed | 1943-02-15 | 1947-06-10 | 0 | Details |
| US2422100A | Position determining system | Expired / Lapsed | 1943-01-06 | 1947-06-10 | 0 | Details |
| US2422133A | Frequency modulated altimeter or distance indicator | Expired / Lapsed | 1942-12-30 | 1947-06-10 | 0 | Details |
| US2422025A | Navigational position plotting | Expired / Lapsed | 1942-11-30 | 1947-06-10 | 0 | Details |
| US2422096A | Direction finding system | Expired / Lapsed | 1942-09-30 | 1947-06-10 | 0 | Details |
| US2422110A | Omnidirectional radio range | Expired / Lapsed | 1942-09-30 | 1947-06-10 | 0 | Details |
| US2422074A | Radio pulse transmission system | Expired / Lapsed | 1942-09-25 | 1947-06-10 | 0 | Details |
| US2421785A | Electric altimeter | Expired / Lapsed | 1939-02-28 | 1947-06-10 | 0 | Details |
| US2421521A | Interlacing system | Expired / Lapsed | 1945-07-26 | 1947-06-03 | 0 | Details |
| US2421727A | Multiplex system having channels added at a relay station | Expired / Lapsed | 1945-04-09 | 1947-06-03 | 0 | Details |
| US2421560A | Differential voltage control system | Expired / Lapsed | 1943-09-03 | 1947-06-03 | 0 | Details |
| US2420868A | Diversity combining circuit | Expired / Lapsed | 1943-04-22 | 1947-05-20 | 0 | Details |
| US2420374A | Pulse multiplex transmission system | Expired / Lapsed | 1944-07-01 | 1947-05-13 | 0 | Details |
| US2420509A | Electron computing device | Expired / Lapsed | 1943-07-28 | 1947-05-13 | 0 | Details |
| US2420200A | Deflecting circuit | Expired / Lapsed | 1944-07-25 | 1947-05-06 | 0 | Details |
| US2420211A | Pulse-echo radio system testing means | Expired / Lapsed | 1944-06-12 | 1947-05-06 | 0 | Details |
| US2420016A | Reflected wave navigation device | Expired / Lapsed | 1944-05-23 | 1947-05-06 | 0 | Details |
| US2420013A | Electron computing device | Expired / Lapsed | 1944-02-19 | 1947-05-06 | 0 | Details |
| US2419994A | Direction finding | Expired / Lapsed | 1942-08-01 | 1947-05-06 | 0 | Details |
| US2419999A | Orienting mechanism for pulse echo systems | Expired / Lapsed | 1942-07-27 | 1947-05-06 | 0 | Details |
| US2419772A | Pulse generator system | Expired / Lapsed | 1944-06-30 | 1947-04-29 | 0 | Details |
| US2419593A | Two-way radio communication system | Expired / Lapsed | 1944-06-29 | 1947-04-29 | 0 | Details |
| US2419793A | Ultra high frequency electron discharge device circuit | Expired / Lapsed | 1944-03-08 | 1947-04-29 | 0 | Details |
| US2419024A | Radio viewing system | Expired / Lapsed | 1945-02-21 | 1947-04-15 | 0 | Details |
| US2419025A | Comparator circuits for radio locators | Expired / Lapsed | 1944-05-30 | 1947-04-15 | 0 | Details |
| US2418780A | Alkali halide target with contrasting colors | Expired / Lapsed | 1942-11-28 | 1947-04-08 | 0 | Details |
| US2418750A | Signal detection system | Expired / Lapsed | 1942-09-04 | 1947-04-08 | 0 | Details |
| US2418779A | Alkali metal halide and luminescent screens of substantiall… | Expired / Lapsed | 1942-07-22 | 1947-04-08 | 0 | Details |
| US2417110A | Electron microscope specimen | Expired / Lapsed | 1943-12-24 | 1947-03-11 | 0 | Details |
| US2417136A | Radio pulse echo system | Expired / Lapsed | 1940-03-18 | 1947-03-11 | 0 | Details |
| US2416914A | Electron discharge device | Expired / Lapsed | 1943-07-30 | 1947-03-04 | 0 | Details |
| US2416794A | Transceiver system | Expired / Lapsed | 1943-02-15 | 1947-03-04 | 0 | Details |
| US2416595A | Photoelectric relay | Expired / Lapsed | 1944-03-15 | 1947-02-25 | 0 | Details |
| US2415918A | Multiple pulse characteristic communication system | Expired / Lapsed | 1945-05-30 | 1947-02-18 | 0 | Details |
| US2416223A | Radio bomb release system | Expired / Lapsed | 1944-04-20 | 1947-02-18 | 0 | Details |
| US2415874A | Stabilized oscillatory system | Expired / Lapsed | 1944-03-27 | 1947-02-18 | 0 | Details |
| US2415981A | Recorder for radio locators | Expired / Lapsed | 1943-08-30 | 1947-02-18 | 0 | Details |
| US2415870A | System for producing a single nonrepetitive scanning trace | Expired / Lapsed | 1942-05-30 | 1947-02-18 | 0 | Details |
| US2415567A | Frequency counter circuit | Expired / Lapsed | 1944-12-02 | 1947-02-11 | 0 | Details |
| US2415566A | Cathode-ray indicator | Expired / Lapsed | 1942-02-21 | 1947-02-11 | 0 | Details |
| US2415352A | Lens for radio-frequency waves | Expired / Lapsed | 1944-04-22 | 1947-02-04 | 0 | Details |
| US2415226A | Method of and apparatus for producing luminous images | Expired / Lapsed | 1943-11-29 | 1947-02-04 | 0 | Details |
| US2415242A | Switching in wave guide transmission system | Expired / Lapsed | 1943-02-25 | 1947-02-04 | 0 | Details |
| US2415211A | Image projection system | Expired / Lapsed | 1943-02-19 | 1947-02-04 | 0 | Details |
| US2415190A | Electronic computer | Expired / Lapsed | 1942-04-30 | 1947-02-04 | 0 | Details |
| US2415191A | Electronic computer | Expired / Lapsed | 1942-04-30 | 1947-02-04 | 0 | Details |
| US2415059A | Television system | Expired / Lapsed | 1944-10-13 | 1947-01-28 | 0 | Details |
| US2414991A | Oscillation generator | Expired / Lapsed | 1944-04-07 | 1947-01-28 | 0 | Details |
| US2414111A | Diversity receiving system | Expired / Lapsed | 1944-03-22 | 1947-01-14 | 0 | Details |
| US2414266A | Antenna | Expired / Lapsed | 1942-06-27 | 1947-01-14 | 0 | Details |
| US2413913A | Frequency discriminator circuit | Expired / Lapsed | 1942-10-29 | 1947-01-07 | 0 | Details |
| US2413348A | Signaling system | Expired / Lapsed | 1942-11-12 | 1946-12-31 | 0 | Details |
| US2413400A | Facsimile apparatus | Expired / Lapsed | 1942-07-14 | 1946-12-31 | 0 | Details |
| US2413063A | Measuring system and triangular wave generator for use ther… | Expired / Lapsed | 1942-06-27 | 1946-12-24 | 0 | Details |
| US2412836A | Electron discharge device | Expired / Lapsed | 1943-08-05 | 1946-12-17 | 0 | Details |
| US2412772A | Electron discharge device generator | Expired / Lapsed | 1943-02-06 | 1946-12-17 | 0 | Details |
| US2412670A | Pulse-echo position indicator | Expired / Lapsed | 1942-06-26 | 1946-12-17 | 0 | Details |
| US2412669A | Pulse-echo position indicator | Expired / Lapsed | 1942-06-19 | 1946-12-17 | 0 | Details |
| US2412822A | Photoelectric device | Expired / Lapsed | 1942-03-26 | 1946-12-17 | 0 | Details |
| US2412702A | Object detection and location | Expired / Lapsed | 1939-02-28 | 1946-12-17 | 0 | Details |
| US2412482A | Discriminator-rectifier circuits | Expired / Lapsed | 1944-08-10 | 1946-12-10 | 0 | Details |
| US2412542A | Deflection circuits | Expired / Lapsed | 1944-05-25 | 1946-12-10 | 0 | Details |
| US2412520A | Television projector tube | Expired / Lapsed | 1943-08-26 | 1946-12-10 | 0 | Details |
| US2412423A | Automatic gain control circuit | Expired / Lapsed | 1943-04-29 | 1946-12-10 | 0 | Details |
| US2412345A | Voltage transformer | Expired / Lapsed | 1943-02-03 | 1946-12-10 | 0 | Details |
| US2412310A | Signal recording system | Expired / Lapsed | 1942-07-31 | 1946-12-10 | 0 | Details |
| US2412291A | Electron discharge device | Expired / Lapsed | 1942-05-30 | 1946-12-10 | 0 | Details |
| US2412249A | Antenna | Expired / Lapsed | 1942-04-23 | 1946-12-10 | 0 | Details |
| US2412111A | Measurement of time between pulses | Expired / Lapsed | 1943-12-30 | 1946-12-03 | 0 | Details |
| US2411853A | Photo radio signaling by frequency modulation | Expired / Lapsed | 1941-07-24 | 1946-12-03 | 0 | Details |
| US2411573A | Frequency counter circuit | Expired / Lapsed | 1944-11-30 | 1946-11-26 | 0 | Details |
| US2411494A | Radio receiver | Expired / Lapsed | 1942-08-18 | 1946-11-19 | 0 | Details |
| US2411034A | Lobe switching antenna | Expired / Lapsed | 1943-02-24 | 1946-11-12 | 0 | Details |
| US2410981A | Superregenerative receiver circuits | Expired / Lapsed | 1942-06-25 | 1946-11-12 | 0 | Details |
| US2410656A | Tuned ultra high frequency transformer | Expired / Lapsed | 1943-06-24 | 1946-11-05 | 0 | Details |
| US2410669A | Program change indicator | Expired / Lapsed | 1943-02-13 | 1946-11-05 | 0 | Details |
| US2410424A | Obstacle detection system | Expired / Lapsed | 1942-08-18 | 1946-11-05 | 0 | Details |
| US2409689A | Electronic computing device | Expired / Lapsed | 1942-11-02 | 1946-10-22 | 0 | Details |
| US2409456A | Radiant energy locating system | Expired / Lapsed | 1944-01-29 | 1946-10-15 | 0 | Details |
| US2409449A | Phase modulator | Expired / Lapsed | 1943-12-30 | 1946-10-15 | 0 | Details |
| US2408727A | Means for circuit time constant measurement | Expired / Lapsed | 1944-07-11 | 1946-10-08 | 0 | Details |
| US2408858A | Adjustment and testing of crystal rectifiers | Expired / Lapsed | 1943-11-29 | 1946-10-08 | 0 | Details |
| US2408848A | Navigational guide system | Expired / Lapsed | 1943-02-05 | 1946-10-08 | 0 | Details |
| US2409038A | Magnetron and circuit therefor | Expired / Lapsed | 1942-12-31 | 1946-10-08 | 0 | Details |
| US2408614A | Surface coating apparatus | Expired / Lapsed | 1944-07-18 | 1946-10-01 | 0 | Details |
| US2408692A | Signaling system | Expired / Lapsed | 1942-04-29 | 1946-10-01 | 0 | Details |
| US2408261A | Pulse generator | Expired / Lapsed | 1944-01-21 | 1946-09-24 | 0 | Details |
| US2407424A | Electron capacity and electron capacity modulator | Expired / Lapsed | 1943-12-08 | 1946-09-10 | 0 | Details |
| US2406978A | Square coding wave generator for secret telecommunication s… | Expired / Lapsed | 1944-08-12 | 1946-09-03 | 0 | Details |
| US2407213A | Radio relaying | Expired / Lapsed | 1944-06-13 | 1946-09-03 | 0 | Details |
| US2407000A | Radio device for indicating doppler effect | Expired / Lapsed | 1941-10-31 | 1946-09-03 | 0 | Details |
| US2407199A | Communication and distance determining system | Expired / Lapsed | 1940-06-29 | 1946-09-03 | 0 | Details |
| US2407198A | Distance and direction determination system | Expired / Lapsed | 1938-03-19 | 1946-09-03 | 0 | Details |
| US2406165A | Communication system | Expired / Lapsed | 1944-07-01 | 1946-08-20 | 0 | Details |
| US2406044A | Selecting mechanism | Expired / Lapsed | 1944-06-30 | 1946-08-20 | 0 | Details |
| US2405991A | Secrecy system | Expired / Lapsed | 1940-07-31 | 1946-08-20 | 0 | Details |
| US2405252A | Secret communication system | Expired / Lapsed | 1942-07-22 | 1946-08-06 | 0 | Details |
| US2405239A | Position determining system | Expired / Lapsed | 1941-02-28 | 1946-08-06 | 0 | Details |
| US2404814A | Selector | Expired / Lapsed | 1945-01-24 | 1946-07-30 | 0 | Details |
| US2404943A | Viewing device | Expired / Lapsed | 1944-10-18 | 1946-07-30 | 0 | Details |
| US2404852A | Automatic frequency control | Expired / Lapsed | 1942-11-07 | 1946-07-30 | 0 | Details |
| US2404942A | Steering device | Expired / Lapsed | 1940-11-06 | 1946-07-30 | 0 | Details |
| US2404712A | Gain control circuit for radiotelegraph | Expired / Lapsed | 1943-12-30 | 1946-07-23 | 0 | Details |
| US2404568A | Automatic frequency control | Expired / Lapsed | 1942-07-21 | 1946-07-23 | 0 | Details |
| US2404026A | Method of and system for translating signals | Expired / Lapsed | 1944-03-29 | 1946-07-16 | 0 | Details |
| US2404250A | Computing system | Expired / Lapsed | 1944-01-22 | 1946-07-16 | 0 | Details |
| US2403918A | Method of operating the electronic chronographs | Expired / Lapsed | 1943-12-29 | 1946-07-16 | 0 | Details |
| US2404343A | Phototube and method of manufacture | Expired / Lapsed | 1943-10-14 | 1946-07-16 | 0 | Details |
| US2403921A | Synchronizing device | Expired / Lapsed | 1943-06-19 | 1946-07-16 | 0 | Details |
| US2403955A | Electron tube circuit | Expired / Lapsed | 1943-05-11 | 1946-07-16 | 0 | Details |
| US2404047A | Electronic computing device | Expired / Lapsed | 1943-01-21 | 1946-07-16 | 0 | Details |
| US2403958A | Wave producing and wave frequency measuring device | Expired / Lapsed | 1942-11-13 | 1946-07-16 | 0 | Details |
| US2404001A | Periodic momentary switch | Expired / Lapsed | 1942-09-10 | 1946-07-16 | 0 | Details |
| US2404093A | Antenna | Expired / Lapsed | 1941-06-28 | 1946-07-16 | 0 | Details |
| US2404046A | Television transmitting apparatus | Expired / Lapsed | 1941-06-21 | 1946-07-16 | 0 | Details |
| US2404306A | Communication system | Expired / Lapsed | 1941-04-01 | 1946-07-16 | 0 | Details |
| US2403628A | Television pickup control system | Expired / Lapsed | 1944-04-25 | 1946-07-09 | 0 | Details |
| US2403725A | High-frequency vacuum tube circuit | Expired / Lapsed | 1943-10-28 | 1946-07-09 | 0 | Details |
| US2403527A | Pulse-echo distance indicator | Expired / Lapsed | 1943-01-30 | 1946-07-09 | 0 | Details |
| US2403657A | Insulating and dielectric material | Expired / Lapsed | 1943-01-29 | 1946-07-09 | 0 | Details |
| US2403609A | Photoelectric system | Expired / Lapsed | 1942-12-19 | 1946-07-09 | 0 | Details |
| US2403615A | Frequency responsive circuit | Expired / Lapsed | 1942-11-30 | 1946-07-09 | 0 | Details |
| US2403561A | Multiplex control system | Expired / Lapsed | 1942-11-28 | 1946-07-09 | 0 | Details |
| US2403429A | Radio beacon system | Expired / Lapsed | 1942-11-02 | 1946-07-09 | 0 | Details |
| US2403800A | Method of and apparatus for drying moisture laden articles | Expired / Lapsed | 1941-12-31 | 1946-07-09 | 0 | Details |
| US2403600A | Receiver for pulse position indicating systems | Expired / Lapsed | 1941-11-29 | 1946-07-09 | 0 | Details |
| US2403626A | Radio pulse position indicating system | Expired / Lapsed | 1941-11-29 | 1946-07-09 | 0 | Details |
| US2403557A | Frequency determining device | Expired / Lapsed | 1941-02-27 | 1946-07-09 | 0 | Details |
| US2403625A | Drift indicator | Expired / Lapsed | 1940-08-16 | 1946-07-09 | 0 | Details |
| US2403622A | Obstacle detecting system | Expired / Lapsed | 1938-07-30 | 1946-07-09 | 0 | Details |
| US2403303A | Ultra high frequency apparatus | Expired / Lapsed | 1943-10-30 | 1946-07-02 | 0 | Details |
| US2403302A | Ultra high frequency apparatus | Expired / Lapsed | 1943-02-25 | 1946-07-02 | 0 | Details |
| US2403289A | Standing wave detector for centimeter waves | Expired / Lapsed | 1942-12-26 | 1946-07-02 | 0 | Details |
| US2403239A | Target electrode for electron discharge tubes | Expired / Lapsed | 1941-08-16 | 1946-07-02 | 0 | Details |
| US2402762A | Method and apparatus for portraying intelligence | Expired / Lapsed | 1942-11-20 | 1946-06-25 | 0 | Details |
| US2402443A | Resonant line and associated circuits | Expired / Lapsed | 1941-08-26 | 1946-06-18 | 0 | Details |
| US2402096A | Control circuit | Expired / Lapsed | 1943-11-20 | 1946-06-11 | 0 | Details |
| US2401855A | Enciphering and deciphering system | Expired / Lapsed | 1942-05-27 | 1946-06-11 | 0 | Details |
| US2402091A | Television system | Expired / Lapsed | 1941-12-31 | 1946-06-11 | 0 | Details |
| US2402067A | Device for secret communication | Expired / Lapsed | 1941-10-30 | 1946-06-11 | 0 | Details |
| US2402083A | Frequency responsive control system | Expired / Lapsed | 1941-09-30 | 1946-06-11 | 0 | Details |
| US2401425A | Light valve | Expired / Lapsed | 1945-02-13 | 1946-06-04 | 0 | Details |
| US2401619A | Pulse signaling system | Expired / Lapsed | 1944-08-19 | 1946-06-04 | 0 | Details |
| US2401404A | Electrical multiplying circuit | Expired / Lapsed | 1944-01-12 | 1946-06-04 | 0 | Details |
| US2401432A | Radio position locator | Expired / Lapsed | 1943-09-29 | 1946-06-04 | 0 | Details |
| US2401527A | Electromechanical multiplying device | Expired / Lapsed | 1943-03-30 | 1946-06-04 | 0 | Details |
| US2401406A | Reciprocal circuit for secret communication | Expired / Lapsed | 1943-03-26 | 1946-06-04 | 0 | Details |
| US2401416A | Amplifier for pulses | Expired / Lapsed | 1942-09-11 | 1946-06-04 | 0 | Details |
| US2401424A | Impulse generator | Expired / Lapsed | 1942-03-27 | 1946-06-04 | 0 | Details |
| US2401441A | Television system | Expired / Lapsed | 1941-03-01 | 1946-06-04 | 0 | Details |
| US2400948A | Noise squelch system | Expired / Lapsed | 1943-03-19 | 1946-05-28 | 0 | Details |
| US2400648A | Timing modulation | Expired / Lapsed | 1943-06-30 | 1946-05-21 | 0 | Details |
| US2400753A | Electron discharge device and associated circuit | Expired / Lapsed | 1942-07-25 | 1946-05-21 | 0 | Details |
| US2400822A | Pulse generator | Expired / Lapsed | 1938-03-16 | 1946-05-21 | 0 | Details |
| US2400066A | Television apparatus | Expired / Lapsed | 1945-03-22 | 1946-05-14 | 0 | Details |
| US2400189A | Measuring the velocity of bullets | Expired / Lapsed | 1944-05-25 | 1946-05-14 | 0 | Details |
| US2400190A | Multirange meter | Expired / Lapsed | 1944-01-12 | 1946-05-14 | 0 | Details |
| US2399481A | Ultra high frequency system | Expired / Lapsed | 1941-08-28 | 1946-04-30 | 0 | Details |
| US2399135A | Frequency divider | Expired / Lapsed | 1943-10-05 | 1946-04-23 | 0 | Details |
| US2398490A | Circuit for removing noise | Expired / Lapsed | 1944-03-01 | 1946-04-16 | 0 | Details |
| US2398596A | Limiter circuit | Expired / Lapsed | 1943-03-24 | 1946-04-16 | 0 | Details |
| US2398551A | Direction finder | Expired / Lapsed | 1942-12-31 | 1946-04-16 | 0 | Details |
| US2398552A | Direction finder | Expired / Lapsed | 1942-12-31 | 1946-04-16 | 0 | Details |
| US2397929A | Reduction in reflection from glass | Expired / Lapsed | 1942-12-30 | 1946-04-09 | 0 | Details |
| US2398095A | Electromagnetic horn radiator | Expired / Lapsed | 1940-08-31 | 1946-04-09 | 0 | Details |
| US2397844A | Signaling apparatus | Expired / Lapsed | 1942-10-01 | 1946-04-02 | 0 | Details |
| US2397207A | Lens coating apparatus | Expired / Lapsed | 1943-10-29 | 1946-03-26 | 0 | Details |
| US2396395A | Electronic switch | Expired / Lapsed | 1942-09-18 | 1946-03-12 | 0 | Details |
| US2396439A | Electron tube circuits | Expired / Lapsed | 1942-03-16 | 1946-03-12 | 0 | Details |
| US2395725A | Frequency modulation receiver tuning indicator | Expired / Lapsed | 1943-03-27 | 1946-02-26 | 0 | Details |
| US2394573A | Keying monitor | Expired / Lapsed | 1943-12-09 | 1946-02-12 | 0 | Details |
| US2394649A | Scanning apparatus | Expired / Lapsed | 1942-04-29 | 1946-02-12 | 0 | Details |
| US2394455A | Method of and means for measuring mechanical impedance | Expired / Lapsed | 1943-12-28 | 1946-02-05 | 0 | Details |
| US2393284A | Ultra short wave system | Expired / Lapsed | 1941-04-30 | 1946-01-22 | 0 | Details |
| US2392978A | Light divider | Expired / Lapsed | 1942-07-27 | 1946-01-15 | 0 | Details |
| US2392586A | Radio communication system | Expired / Lapsed | 1943-11-11 | 1946-01-08 | 0 | Details |
| US2392672A | Program control receiver | Expired / Lapsed | 1942-07-24 | 1946-01-08 | 0 | Details |
| US2391780A | Electron discharge device | Expired / Lapsed | 1943-10-13 | 1945-12-25 | 0 | Details |
| US2391776A | Intelligence transmission system | Expired / Lapsed | 1943-05-29 | 1945-12-25 | 0 | Details |
| US2391765A | Facsimile apparatus | Expired / Lapsed | 1942-09-21 | 1945-12-25 | 0 | Details |
| US2389986A | Permeability tuning system | Expired / Lapsed | 1943-06-11 | 1945-11-27 | 0 | Details |
| US2389356A | Method of reduction of selective fading | Expired / Lapsed | 1942-11-24 | 1945-11-20 | 0 | Details |
| US2388812A | Electronic trigger method and circuit | Expired / Lapsed | 1943-12-27 | 1945-11-13 | 0 | Details |
| US2388824A | Method of and apparatus for heattreating dielectric materia… | Expired / Lapsed | 1943-03-09 | 1945-11-13 | 0 | Details |
| US2389004A | Keyed multifrequency negative resistance apparatus | Expired / Lapsed | 1942-06-26 | 1945-11-13 | 0 | Details |
| US2388531A | Low-frequency signaling | Expired / Lapsed | 1942-12-05 | 1945-11-06 | 0 | Details |
| US2388576A | Radio signaling system | Expired / Lapsed | 1942-09-05 | 1945-11-06 | 0 | Details |
| US2388530A | Power line signaling system | Expired / Lapsed | 1942-04-01 | 1945-11-06 | 0 | Details |
| US2387852A | Precision measuring apparatus | Expired / Lapsed | 1943-10-25 | 1945-10-30 | 0 | Details |
| US2388052A | Signaling | Expired / Lapsed | 1941-04-18 | 1945-10-30 | 0 | Details |
| US2387544A | Frequency and phase comparison detection and control system | Expired / Lapsed | 1943-08-27 | 1945-10-23 | 0 | Details |
| US2387472A | Square-law detector | Expired / Lapsed | 1943-08-17 | 1945-10-23 | 0 | Details |
| US2387158A | Coaxial load resistor for ultra high frequency measurements | Expired / Lapsed | 1942-02-25 | 1945-10-16 | 0 | Details |
| US2386074A | Color television | Expired / Lapsed | 1943-11-29 | 1945-10-02 | 0 | Details |
| US2385563A | Deflection control system | Expired / Lapsed | 1943-01-30 | 1945-09-25 | 0 | Details |
| US2385641A | Automatic recording system | Expired / Lapsed | 1942-02-11 | 1945-09-25 | 0 | Details |
| US2384722A | Facsimile recorder | Expired / Lapsed | 1942-10-24 | 1945-09-11 | 0 | Details |
| US2384260A | Television apparatus | Expired / Lapsed | 1944-09-21 | 1945-09-04 | 0 | Details |
| US2383822A | Oscillation generator | Expired / Lapsed | 1942-03-04 | 1945-08-28 | 0 | Details |
| US2383126A | Spaced wave keying | Expired / Lapsed | 1943-07-08 | 1945-08-21 | 0 | Details |
| US2383322A | Multiband receiver with band spread | Expired / Lapsed | 1942-07-25 | 1945-08-21 | 0 | Details |
| US2382822A | Cathode ray beam deflecting circuits | Expired / Lapsed | 1942-06-30 | 1945-08-14 | 0 | Details |
| US2382615A | Oscillator tuning system | Expired / Lapsed | 1942-05-16 | 1945-08-14 | 0 | Details |
| US2381928A | Frequency modulated pulse signaling | Expired / Lapsed | 1942-03-05 | 1945-08-14 | 0 | Details |
| US2381496A | Method of generating currents for nonsignaling purposes | Expired / Lapsed | 1942-10-10 | 1945-08-07 | 0 | Details |
| US2380947A | Wave length modulator and control means | Expired / Lapsed | 1941-05-14 | 1945-08-07 | 0 | Details |
| US2380868A | Frequency measuring system | Expired / Lapsed | 1943-05-29 | 1945-07-31 | 0 | Details |
| US2380791A | Resonance indicating apparatus | Expired / Lapsed | 1942-05-28 | 1945-07-31 | 0 | Details |
| US2379899A | Radio communication system | Expired / Lapsed | 1940-11-29 | 1945-07-10 | 0 | Details |
| US2379484A | Variable gain audio amplifier system and method | Expired / Lapsed | 1943-09-27 | 1945-07-03 | 0 | Details |
| US2379689A | Frequency control circuit | Expired / Lapsed | 1943-01-27 | 1945-07-03 | 0 | Details |
| US2379664A | Electrical connector for loudspeakers and the like | Expired / Lapsed | 1942-08-29 | 1945-07-03 | 0 | Details |
| US2379739A | Range quadrant identification circuit | Expired / Lapsed | 1942-03-31 | 1945-07-03 | 0 | Details |
| US2379790A | Dichroic reflector | Expired / Lapsed | 1942-03-31 | 1945-07-03 | 0 | Details |
| US2377327A | Automatic frequency control system | Expired / Lapsed | 1942-09-29 | 1945-06-05 | 0 | Details |
| US2377326A | Automatic frequency control system | Expired / Lapsed | 1942-04-06 | 1945-06-05 | 0 | Details |
| US2376438A | Voltage regulator circuit | Expired / Lapsed | 1943-06-18 | 1945-05-22 | 0 | Details |
| US2376034A | Facsimile apparatus | Expired / Lapsed | 1942-11-30 | 1945-05-15 | 0 | Details |
| US2375950A | Frequency divider | Expired / Lapsed | 1942-03-04 | 1945-05-15 | 0 | Details |
| US2374735A | Combined discriminator and carrier filter circuits | Expired / Lapsed | 1943-03-31 | 1945-05-01 | 0 | Details |
| US2374746A | Frequency modulation receiver | Expired / Lapsed | 1942-09-21 | 1945-05-01 | 0 | Details |
| US2373616A | Frequency modulation detector | Expired / Lapsed | 1942-12-15 | 1945-04-10 | 0 | Details |
| US2372929A | Composite structure | Expired / Lapsed | 1941-04-01 | 1945-04-03 | 0 | Details |
| US2371905A | Phase shifting system | Expired / Lapsed | 1941-01-31 | 1945-03-20 | 0 | Details |
| US2371373A | Balanced frequency modulation system | Expired / Lapsed | 1943-06-12 | 1945-03-13 | 0 | Details |
| US2371415A | Remote control circuit | Expired / Lapsed | 1942-11-30 | 1945-03-13 | 0 | Details |
| US2370426A | Electron tube circuit | Expired / Lapsed | 1943-03-29 | 1945-02-27 | 0 | Details |
| US2370423A | High frequency tank circuit | Expired / Lapsed | 1941-10-31 | 1945-02-27 | 0 | Details |
| US2370160A | Electrical transmission of messages | Expired / Lapsed | 1940-12-18 | 1945-02-27 | 0 | Details |
| US2370053A | Directive antenna system | Expired / Lapsed | 1940-12-31 | 1945-02-20 | 0 | Details |
| US2369268A | Radio repeater | Expired / Lapsed | 1942-05-27 | 1945-02-13 | 0 | Details |
| US2369230A | Energy conservation in radio systems | Expired / Lapsed | 1942-03-23 | 1945-02-13 | 0 | Details |
| US2368884A | Television transmitting apparatus | Expired / Lapsed | 1942-08-21 | 1945-02-06 | 0 | Details |
| US2368761A | Means for registering radio listening habits | Expired / Lapsed | 1942-07-30 | 1945-02-06 | 0 | Details |
| US2368778A | Automatic program selector | Expired / Lapsed | 1942-06-16 | 1945-02-06 | 0 | Details |
| US2368643A | Variable reactance and control circuit therefor | Expired / Lapsed | 1941-12-31 | 1945-02-06 | 0 | Details |
| US2368328A | High frequency generator | Expired / Lapsed | 1940-03-30 | 1945-01-30 | 0 | Details |
| US2367378A | Radio alarm system | Expired / Lapsed | 1942-08-26 | 1945-01-16 | 0 | Details |
| US2367293A | Method of preparing control track records | Expired / Lapsed | 1942-06-01 | 1945-01-16 | 0 | Details |
| US2367576A | Ultra-high-frequency tuning apparatus | Expired / Lapsed | 1942-04-01 | 1945-01-16 | 0 | Details |
| US2367327A | Radio warning system | Expired / Lapsed | 1942-02-27 | 1945-01-16 | 0 | Details |
| US2367116A | Wave control circuit | Expired / Lapsed | 1942-01-31 | 1945-01-09 | 0 | Details |
| US2366358A | Television amplifier circuit | Expired / Lapsed | 1943-05-07 | 1945-01-02 | 0 | Details |
| US2366355A | Indicating device | Expired / Lapsed | 1942-12-22 | 1945-01-02 | 0 | Details |
| US2366307A | Television apparatus | Expired / Lapsed | 1942-10-29 | 1945-01-02 | 0 | Details |
| US2366614A | Resistance having a low temperature coefficient | Expired / Lapsed | 1942-10-10 | 1945-01-02 | 0 | Details |
| US2366357A | Electronic relay | Expired / Lapsed | 1942-05-30 | 1945-01-02 | 0 | Details |
| US2366434A | Error detector for telegraph printers | Expired / Lapsed | 1942-04-07 | 1945-01-02 | 0 | Details |
| US2365450A | Radio telegraph multiplex system | Expired / Lapsed | 1942-04-29 | 1944-12-19 | 0 | Details |
| US2364952A | Diversity receiving system | Expired / Lapsed | 1942-03-13 | 1944-12-12 | 0 | Details |
| US2364291A | Intermediate frequency transformer | Expired / Lapsed | 1940-10-30 | 1944-12-05 | 0 | Details |
| US2363652A | Frequency modulation discriminator circuit | Expired / Lapsed | 1943-04-29 | 1944-11-28 | 0 | Details |
| US2363651A | Superregenerative receiver system | Expired / Lapsed | 1943-03-06 | 1944-11-28 | 0 | Details |
| US2363813A | Electrical control circuit | Expired / Lapsed | 1941-12-27 | 1944-11-28 | 0 | Details |
| US2363822A | Saw-tooth deflection | Expired / Lapsed | 1941-01-02 | 1944-11-28 | 0 | Details |
| US2363342A | Servo system | Expired / Lapsed | 1942-07-29 | 1944-11-21 | 0 | Details |
| US2362561A | Horn radiator | Expired / Lapsed | 1940-12-12 | 1944-11-14 | 0 | Details |
| US2362000A | Reception of frequency modulated waves | Expired / Lapsed | 1941-12-20 | 1944-11-07 | 0 | Details |
| US2361634A | Record reproduction circuit | Expired / Lapsed | 1942-10-06 | 1944-10-31 | 0 | Details |
| US2361625A | Frequency and phase modulation receiver | Expired / Lapsed | 1941-12-22 | 1944-10-31 | 0 | Details |
| US2361437A | Pulse signaling system | Expired / Lapsed | 1940-12-24 | 1944-10-31 | 0 | Details |
| US2360663A | Electrical biasing means | Expired / Lapsed | 1941-02-28 | 1944-10-17 | 0 | Details |
| US2358454A | Automatic circuit tuning | Expired / Lapsed | 1942-04-29 | 1944-09-19 | 0 | Details |
| US2358382A | Frequency modulation signal system | Expired / Lapsed | 1941-08-29 | 1944-09-19 | 0 | Details |
| US2358545A | Television system | Expired / Lapsed | 1941-07-31 | 1944-09-19 | 0 | Details |
| US2358297A | Blocking oscillator | Expired / Lapsed | 1940-07-31 | 1944-09-19 | 0 | Details |
| US2357925A | Combined reed and relay device | Expired / Lapsed | 1942-08-07 | 1944-09-12 | 0 | Details |
| US2357984A | Automatic frequency control system | Expired / Lapsed | 1935-05-03 | 1944-09-12 | 0 | Details |
| US2357706A | Heating and cooling system | Expired / Lapsed | 1942-06-29 | 1944-09-05 | 0 | Details |
| US2357652A | Rectifier timing circuit | Expired / Lapsed | 1942-05-25 | 1944-09-05 | 0 | Details |
| US2357314A | Cavity resonator circuit | Expired / Lapsed | 1941-01-04 | 1944-09-05 | 0 | Details |
| US2357313A | High frequency resonator and circuit therefor | Expired / Lapsed | 1940-10-01 | 1944-09-05 | 0 | Details |
| US2356414A | Tunable resonant cavity device | Expired / Lapsed | 1941-02-26 | 1944-08-22 | 0 | Details |
| US2355194A | Mechanical impedance measuring device | Expired / Lapsed | 1943-03-30 | 1944-08-08 | 0 | Details |
| US2355502A | Signal indicator and recorder | Expired / Lapsed | 1941-02-27 | 1944-08-08 | 0 | Details |
| US2354827A | Frequency control | Expired / Lapsed | 1941-05-23 | 1944-08-01 | 0 | Details |
| US2354295A | Sound recording system | Expired / Lapsed | 1942-06-20 | 1944-07-25 | 0 | Details |
| US2354148A | Push-button tuner for radio receivers | Expired / Lapsed | 1942-09-15 | 1944-07-18 | 0 | Details |
| US2354141A | Universal resistance capacitance filter | Expired / Lapsed | 1942-08-26 | 1944-07-18 | 0 | Details |
| US2353499A | Radio alarm system | Expired / Lapsed | 1942-07-04 | 1944-07-11 | 0 | Details |
| US2353162A | Frequency modulation | Expired / Lapsed | 1942-05-29 | 1944-07-11 | 0 | Details |
| US2353203A | Frequency modulator | Expired / Lapsed | 1942-04-27 | 1944-07-11 | 0 | Details |
| US2352777A | Range finder | Expired / Lapsed | 1942-04-30 | 1944-07-04 | 0 | Details |
| US2352541A | Electronic synchronization system | Expired / Lapsed | 1942-04-20 | 1944-06-27 | 0 | Details |
| US2352305A | Microphone | Expired / Lapsed | 1941-01-02 | 1944-06-27 | 0 | Details |
| US2351760A | Color television system | Expired / Lapsed | 1941-08-29 | 1944-06-20 | 0 | Details |
| US2351193A | Frequency modulation detector circuit | Expired / Lapsed | 1942-06-13 | 1944-06-13 | 0 | Details |
| US2351368A | Reactance tube | Expired / Lapsed | 1942-06-03 | 1944-06-13 | 0 | Details |
| US2351192A | Frequency modulation receiver | Expired / Lapsed | 1942-03-13 | 1944-06-13 | 0 | Details |
| US2351212A | Convertible demodulator circuit | Expired / Lapsed | 1942-02-10 | 1944-06-13 | 0 | Details |
| US2351221A | Superregenerative receiver circuit | Expired / Lapsed | 1941-11-08 | 1944-06-13 | 0 | Details |
| US2351185A | Wireless transmitting or receiving set | Expired / Lapsed | 1940-06-17 | 1944-06-13 | 0 | Details |
| US2350820A | Aircraft altitude determining system | Expired / Lapsed | 1942-08-10 | 1944-06-06 | 0 | Details |
| US2350536A | Synchronizing signal generator | Expired / Lapsed | 1942-07-30 | 1944-06-06 | 0 | Details |
| US2350008A | Facsimile apparatus | Expired / Lapsed | 1942-07-30 | 1944-05-30 | 0 | Details |
| US2350171A | Reactance controlled generator | Expired / Lapsed | 1942-06-19 | 1944-05-30 | 0 | Details |
| US2349849A | Gas tube relay circuits | Expired / Lapsed | 1942-03-13 | 1944-05-30 | 0 | Details |
| US2350069A | Oscillograph sweep circuit | Expired / Lapsed | 1942-02-20 | 1944-05-30 | 0 | Details |
| US2349881A | Frequency modulation receiver | Expired / Lapsed | 1941-11-27 | 1944-05-30 | 0 | Details |
| US2349885A | Oscillation generator | Expired / Lapsed | 1941-10-25 | 1944-05-30 | 0 | Details |
| US2348986A | Resonant cavity magnetron | Expired / Lapsed | 1940-10-24 | 1944-05-16 | 0 | Details |
| US2348133A | Method and apparatus for developing electron beams | Expired / Lapsed | 1942-09-29 | 1944-05-02 | 0 | Details |
| US2347084A | Noiseless sound system | Expired / Lapsed | 1942-09-15 | 1944-04-18 | 0 | Details |
| US2345951A | Radio relay control system | Expired / Lapsed | 1942-03-19 | 1944-04-04 | 0 | Details |
| US2346020A | Modulation amplifier and modulator | Expired / Lapsed | 1942-02-05 | 1944-04-04 | 0 | Details |
| US2345762A | Noise limiter circuit | Expired / Lapsed | 1941-05-27 | 1944-04-04 | 0 | Details |
| US2345101A | Frequency modulator | Expired / Lapsed | 1942-03-27 | 1944-03-28 | 0 | Details |
| US2345472A | Remote control system | Expired / Lapsed | 1939-10-20 | 1944-03-28 | 0 | Details |
| US2344813A | Radio repeater | Expired / Lapsed | 1941-09-26 | 1944-03-21 | 0 | Details |
| US2344745A | Electrical circuit | Expired / Lapsed | 1941-09-26 | 1944-03-21 | 0 | Details |
| US2344618A | Radio air raid warning system | Expired / Lapsed | 1941-07-31 | 1944-03-21 | 0 | Details |
| US2344678A | Frequency divider network | Expired / Lapsed | 1941-03-29 | 1944-03-21 | 0 | Details |
| US2343453A | Electrical heating apparatus | Expired / Lapsed | 1942-05-30 | 1944-03-07 | 0 | Details |
| US2343471A | Binaural translating system | Expired / Lapsed | 1941-03-29 | 1944-03-07 | 0 | Details |
| US2343099A | Frequency modulation system | Expired / Lapsed | 1942-09-09 | 1944-02-29 | 0 | Details |
| US2342897A | Electron discharge device system | Expired / Lapsed | 1941-07-01 | 1944-02-29 | 0 | Details |
| US2342943A | Television transmitting system | Expired / Lapsed | 1940-12-24 | 1944-02-29 | 0 | Details |
| US2341649A | Frequency control | Expired / Lapsed | 1941-05-23 | 1944-02-15 | 0 | Details |
| US2341232A | Ninety degree phase shifter | Expired / Lapsed | 1942-09-30 | 1944-02-08 | 0 | Details |
| US2341040A | Frequency modulator | Expired / Lapsed | 1940-11-22 | 1944-02-08 | 0 | Details |
| US2340364A | Audio transmission circuit | Expired / Lapsed | 1942-08-22 | 1944-02-01 | 0 | Details |
| US2340432A | Phase modulation receiver | Expired / Lapsed | 1942-05-23 | 1944-02-01 | 0 | Details |
| US2340798A | Remote control system | Expired / Lapsed | 1941-07-23 | 1944-02-01 | 0 | Details |
| US2340429A | Amplitude modulation limiter circuit | Expired / Lapsed | 1941-07-10 | 1944-02-01 | 0 | Details |
| US2340749A | Variable permeability tuning system | Expired / Lapsed | 1941-04-16 | 1944-02-01 | 0 | Details |
| US2340443A | Controlled degenerative feedback circuits | Expired / Lapsed | 1938-12-13 | 1944-02-01 | 0 | Details |
| US2339851A | Automatic tuning control | Expired / Lapsed | 1941-05-28 | 1944-01-25 | 0 | Details |
| US2339392A | Cathode | Expired / Lapsed | 1942-10-06 | 1944-01-18 | 0 | Details |
| US2338234A | Evaporation of transparent material on glass | Expired / Lapsed | 1941-01-02 | 1944-01-04 | 0 | Details |
| US2338497A | Lens coating | Expired / Lapsed | 1940-07-31 | 1944-01-04 | 0 | Details |
| US2337710A | Antenna | Expired / Lapsed | 1941-11-01 | 1943-12-28 | 0 | Details |
| US2337132A | Electronic control | Expired / Lapsed | 1942-08-31 | 1943-12-21 | 0 | Details |
| US2337196A | Signal and noise control system | Expired / Lapsed | 1942-03-27 | 1943-12-21 | 0 | Details |
| US2337328A | Electrical measuring circuit | Expired / Lapsed | 1941-12-30 | 1943-12-21 | 0 | Details |
| US2337392A | Frequency modulated carrier wave receiver circuit | Expired / Lapsed | 1941-06-19 | 1943-12-21 | 0 | Details |
| US2337214A | Ultra short wave apparatus | Expired / Lapsed | 1941-04-17 | 1943-12-21 | 0 | Details |
| US2335934A | Phase modulation | Expired / Lapsed | 1942-06-10 | 1943-12-07 | 0 | Details |
| US2334356A | Vacuum gauge | Expired / Lapsed | 1941-05-28 | 1943-11-16 | 0 | Details |
| US2334189A | Relay system and associated circuits therefor | Expired / Lapsed | 1940-06-05 | 1943-11-16 | 0 | Details |
| US2334020A | Glass-to-metal seal | Expired / Lapsed | 1941-10-08 | 1943-11-09 | 0 | Details |
| US2333688A | Distance measuring system | Expired / Lapsed | 1937-10-29 | 1943-11-09 | 0 | Details |
| US2333335A | Diversity receiving system | Expired / Lapsed | 1941-08-12 | 1943-11-02 | 0 | Details |
| US2332681A | Synchronizing of deflecting circuits | Expired / Lapsed | 1941-11-29 | 1943-10-26 | 0 | Details |
| US2333001A | Automatic lighter and display device | Expired / Lapsed | 1941-06-25 | 1943-10-26 | 0 | Details |
| US2333005A | Method for retaining insulators within tubes | Expired / Lapsed | 1941-05-15 | 1943-10-26 | 0 | Details |
| US2332253A | Combining unit | Expired / Lapsed | 1942-01-21 | 1943-10-19 | 0 | Details |
| US2331136A | Transmission line seal and insulator | Expired / Lapsed | 1939-12-23 | 1943-10-05 | 0 | Details |
| US2329777A | Electron discharge device | Expired / Lapsed | 1941-10-30 | 1943-09-21 | 0 | Details |
| US2329339A | Electrical circuit | Expired / Lapsed | 1942-03-07 | 1943-09-14 | 0 | Details |
| US2329624A | Television recording apparatus | Expired / Lapsed | 1941-01-31 | 1943-09-14 | 0 | Details |
| US2328985A | Phase indicating apparatus | Expired / Lapsed | 1941-10-31 | 1943-09-07 | 0 | Details |
| US2329137A | Deflection generator | Expired / Lapsed | 1941-05-23 | 1943-09-07 | 0 | Details |
| US2328292A | Method of depositing phosphor materials | Expired / Lapsed | 1941-12-19 | 1943-08-31 | 0 | Details |
| US2326314A | Frequency modulation | Expired / Lapsed | 1941-08-30 | 1943-08-10 | 0 | Details |
| US2325652A | Drying method | Expired / Lapsed | 1941-08-20 | 1943-08-03 | 0 | Details |
| US2324504A | Television transmitting system | Expired / Lapsed | 1940-11-28 | 1943-07-20 | 0 | Details |
| US2324279A | Amplifier | Expired / Lapsed | 1941-11-29 | 1943-07-13 | 0 | Details |
| US2323966A | Amplifier | Expired / Lapsed | 1938-10-07 | 1943-07-13 | 0 | Details |
| US2323534A | Short dot test equipment | Expired / Lapsed | 1941-12-12 | 1943-07-06 | 0 | Details |
| US2323596A | Frequency modulation receiver | Expired / Lapsed | 1941-06-17 | 1943-07-06 | 0 | Details |
| US2323598A | Variable signal response network | Expired / Lapsed | 1941-01-07 | 1943-07-06 | 0 | Details |
| US2323376A | Variable permeability tuning system | Expired / Lapsed | 1940-04-27 | 1943-07-06 | 0 | Details |
| US2323634A | Low frequency amplifier | Expired / Lapsed | 1937-08-07 | 1943-07-06 | 0 | Details |
| US2323148A | Electrical contact assembly for use in electron discharge d… | Expired / Lapsed | 1942-01-16 | 1943-06-29 | 0 | Details |
| US2323126A | Multithrow relay | Expired / Lapsed | 1941-12-20 | 1943-06-29 | 0 | Details |
| US2322807A | Electron discharge device and system | Expired / Lapsed | 1940-12-28 | 1943-06-29 | 0 | Details |
| US2323201A | Tuned circuit and associated devices therefor | Expired / Lapsed | 1939-01-07 | 1943-06-29 | 0 | Details |
| US2322588A | Transmitting system and apparatus | Expired / Lapsed | 1941-03-22 | 1943-06-22 | 0 | Details |
| US2322361A | Electronic device | Expired / Lapsed | 1937-12-14 | 1943-06-22 | 0 | Details |
| US2321269A | Frequency modulation | Expired / Lapsed | 1941-11-21 | 1943-06-08 | 0 | Details |
| US2321315A | Frequency measuring system | Expired / Lapsed | 1941-05-09 | 1943-06-08 | 0 | Details |
| US2321343A | Television system | Expired / Lapsed | 1940-10-23 | 1943-06-08 | 0 | Details |
| US2320476A | Phase measurement | Expired / Lapsed | 1941-09-30 | 1943-06-01 | 0 | Details |
| US2320428A | Oscillating amplifier and detecting system | Expired / Lapsed | 1941-04-30 | 1943-06-01 | 0 | Details |
| US2320808A | Wireless receiving set | Expired / Lapsed | 1940-06-22 | 1943-06-01 | 0 | Details |
| US2318237A | Antenna feed system | Expired / Lapsed | 1940-06-08 | 1943-05-04 | 0 | Details |
| US2317503A | Transmission line | Expired / Lapsed | 1939-08-16 | 1943-04-27 | 0 | Details |
| US2316902A | Noise control circuit | Expired / Lapsed | 1941-10-22 | 1943-04-20 | 0 | Details |
| US2315784A | Electrical circuit | Expired / Lapsed | 1941-11-25 | 1943-04-06 | 0 | Details |
| US2315296A | High frequency amplifier circuits | Expired / Lapsed | 1940-05-03 | 1943-03-30 | 0 | Details |
| US2314707A | Signaling system | Expired / Lapsed | 1941-03-07 | 1943-03-23 | 0 | Details |
| US2313966A | Cathode ray tube system | Expired / Lapsed | 1941-03-31 | 1943-03-16 | 0 | Details |
| US2313967A | Cathode ray oscillograph for recording transients | Expired / Lapsed | 1939-10-18 | 1943-03-16 | 0 | Details |
| US2313129A | Art of mounting piezoelectric crystals | Expired / Lapsed | 1941-01-31 | 1943-03-09 | 0 | Details |
| US2313699A | Power measuring device | Expired / Lapsed | 1940-04-27 | 1943-03-09 | 0 | Details |
| US2313666A | Logarithmic instrument circuit | Expired / Lapsed | 1940-01-26 | 1943-03-09 | 0 | Details |
| US2313071A | Oscillation generator and modulator | Expired / Lapsed | 1931-10-10 | 1943-03-09 | 0 | Details |
| US2312783A | Frequency variation response circuit | Expired / Lapsed | 1941-10-25 | 1943-03-02 | 0 | Details |
| US2312792A | Color television system | Expired / Lapsed | 1941-08-14 | 1943-03-02 | 0 | Details |
| US2312761A | Sweep circuit generator for cathode ray tubes | Expired / Lapsed | 1940-09-26 | 1943-03-02 | 0 | Details |
| US2312748A | Volume control circuit | Expired / Lapsed | 1939-06-22 | 1943-03-02 | 0 | Details |
| US2312070A | Frequency discriminator circuit | Expired / Lapsed | 1940-12-07 | 1943-02-23 | 0 | Details |
| US2312079A | Frequency control | Expired / Lapsed | 1940-09-06 | 1943-02-23 | 0 | Details |
| US2312127A | Photoelectric controlled oscillator device | Expired / Lapsed | 1939-11-07 | 1943-02-23 | 0 | Details |
| US2311522A | High frequency receiver | Expired / Lapsed | 1941-08-29 | 1943-02-16 | 0 | Details |
| US2311159A | Production of sound records | Expired / Lapsed | 1940-06-01 | 1943-02-16 | 0 | Details |
| US2311445A | Sound operated control system | Expired / Lapsed | 1939-05-31 | 1943-02-16 | 0 | Details |
| US2310294A | Electromagnetic horn antenna | Expired / Lapsed | 1941-03-01 | 1943-02-09 | 0 | Details |
| US2310863A | Luminescent screen | Expired / Lapsed | 1941-01-25 | 1943-02-09 | 0 | Details |
| US2310342A | Balanced direct and alternating current amplifiers | Expired / Lapsed | 1940-11-29 | 1943-02-09 | 0 | Details |
| US2310260A | Wave length modulation | Expired / Lapsed | 1940-07-18 | 1943-02-09 | 0 | Details |
| US2310692A | Method of and means for reducing multiple signals | Expired / Lapsed | 1939-06-16 | 1943-02-09 | 0 | Details |
| US2310328A | Square wave generator | Expired / Lapsed | 1938-05-25 | 1943-02-09 | 0 | Details |
| US2309678A | Frequency modulation system | Expired / Lapsed | 1940-08-31 | 1943-02-02 | 0 | Details |
| US2309672A | Cathode ray beam deflecting circuit | Expired / Lapsed | 1940-03-21 | 1943-02-02 | 0 | Details |
| US2309222A | Telegraph code converter | Expired / Lapsed | 1941-03-22 | 1943-01-26 | 0 | Details |
| US2307693A | Frequency multiplier | Expired / Lapsed | 1941-04-30 | 1943-01-05 | 0 | Details |
| US2307316A | Frequency meter | Expired / Lapsed | 1941-02-13 | 1943-01-05 | 0 | Details |
| US2307188A | Television system | Expired / Lapsed | 1940-11-30 | 1943-01-05 | 0 | Details |
| US2307438A | Piezoelectric device | Expired / Lapsed | 1940-09-04 | 1943-01-05 | 0 | Details |
| US2307099A | High speed telegraph system | Expired / Lapsed | 1939-09-27 | 1943-01-05 | 0 | Details |
| US2306687A | Means for improving reception during selective fading | Expired / Lapsed | 1941-10-21 | 1942-12-29 | 0 | Details |
| US2305930A | Television system | Expired / Lapsed | 1940-12-31 | 1942-12-22 | 0 | Details |
| US2306052A | Phase modulation circuit | Expired / Lapsed | 1940-12-21 | 1942-12-22 | 0 | Details |
| US2306291A | Method of assembling the magnet system for acoustic devices | Expired / Lapsed | 1940-06-25 | 1942-12-22 | 0 | Details |
| US2305617A | Cathode ray tube and circuit | Expired / Lapsed | 1940-03-15 | 1942-12-22 | 0 | Details |
| US2304377A | Automatic frequency control system | Expired / Lapsed | 1941-02-11 | 1942-12-08 | 0 | Details |
| US2304755A | Telelectroscope | Expired / Lapsed | 1940-10-11 | 1942-12-08 | 0 | Details |
| US2303444A | Modulation system | Expired / Lapsed | 1941-05-27 | 1942-12-01 | 0 | Details |
| US2303644A | Antenna system | Expired / Lapsed | 1941-03-12 | 1942-12-01 | 0 | Details |
| US2303862A | Oscillation generator and amplifier | Expired / Lapsed | 1940-06-01 | 1942-12-01 | 0 | Details |
| US2304057A | Keystone correction circuit | Expired / Lapsed | 1939-12-15 | 1942-12-01 | 0 | Details |
| US2303960A | Motion picture projector for television use | Expired / Lapsed | 1939-08-22 | 1942-12-01 | 0 | Details |
| US2302852A | Wide band transmitting and receiving system | Expired / Lapsed | 1941-03-07 | 1942-11-24 | 0 | Details |
| US2302951A | Diversity receiving system | Expired / Lapsed | 1940-08-27 | 1942-11-24 | 0 | Details |
| US2301649A | Signal receiving system | Expired / Lapsed | 1941-06-26 | 1942-11-10 | 0 | Details |
| US2300632A | Oscillation generator | Expired / Lapsed | 1940-06-22 | 1942-11-03 | 0 | Details |
| US2299945A | Direct current reinserting circuit | Expired / Lapsed | 1940-11-27 | 1942-10-27 | 0 | Details |
| US2300052A | Electron discharge device system | Expired / Lapsed | 1940-05-04 | 1942-10-27 | 0 | Details |
| US2299942A | Power converter and regulator | Expired / Lapsed | 1939-11-07 | 1942-10-27 | 0 | Details |
| US2300189A | Cathode ray deflection apparatus | Expired / Lapsed | 1939-04-26 | 1942-10-27 | 0 | Details |
| US2299391A | Radio receiver | Expired / Lapsed | 1941-05-27 | 1942-10-20 | 0 | Details |
| US2299292A | Automatic volume control system | Expired / Lapsed | 1939-12-28 | 1942-10-20 | 0 | Details |
| US2298911A | Optical system for facsimile transmitters | Expired / Lapsed | 1941-04-01 | 1942-10-13 | 0 | Details |
| US2298908A | Powdered metal | Expired / Lapsed | 1940-12-31 | 1942-10-13 | 0 | Details |
| US2298435A | Radio relaying | Expired / Lapsed | 1940-11-26 | 1942-10-13 | 0 | Details |
| US2298438A | Frequency modulation system | Expired / Lapsed | 1940-10-17 | 1942-10-13 | 0 | Details |
| US2298409A | Multiplexing | Expired / Lapsed | 1940-06-19 | 1942-10-13 | 0 | Details |
| US2298437A | Frequency modulation | Expired / Lapsed | 1940-06-05 | 1942-10-13 | 0 | Details |
| US2298436A | Frequency modulation | Expired / Lapsed | 1940-06-05 | 1942-10-13 | 0 | Details |
| US2298974A | Glass-to-metal seal | Expired / Lapsed | 1939-11-30 | 1942-10-13 | 0 | Details |
| US2298476A | Televisible guiding system | Expired / Lapsed | 1939-07-19 | 1942-10-13 | 0 | Details |
| US2298220A | Telegraph signal regenerator | Expired / Lapsed | 1940-12-28 | 1942-10-06 | 0 | Details |
| US2297926A | Frequency modulated transmitter | Expired / Lapsed | 1940-10-30 | 1942-10-06 | 0 | Details |
| US2296919A | Direct-current insertion | Expired / Lapsed | 1940-07-17 | 1942-09-29 | 0 | Details |
| US2296920A | Signal transmission circuit | Expired / Lapsed | 1940-01-24 | 1942-09-29 | 0 | Details |
| US2296962A | Frequency modulation | Expired / Lapsed | 1939-12-22 | 1942-09-29 | 0 | Details |
| US2296384A | Relay system monitor | Expired / Lapsed | 1940-04-11 | 1942-09-22 | 0 | Details |
| US2296393A | Noise limiter | Expired / Lapsed | 1940-03-16 | 1942-09-22 | 0 | Details |
| US2296092A | Differential detector circuits | Expired / Lapsed | 1941-07-17 | 1942-09-15 | 0 | Details |
| US2295802A | Reflective optical system | Expired / Lapsed | 1941-07-01 | 1942-09-15 | 0 | Details |
| US2296091A | Frequency modulation detector circuits | Expired / Lapsed | 1941-06-25 | 1942-09-15 | 0 | Details |
| US2296107A | Ultra high frequency converter | Expired / Lapsed | 1941-05-09 | 1942-09-15 | 0 | Details |
| US2296101A | Frequency modulation receiver tuning indicator | Expired / Lapsed | 1940-10-25 | 1942-09-15 | 0 | Details |
| US2296100A | Frequency modulated wave receiver | Expired / Lapsed | 1940-08-20 | 1942-09-15 | 0 | Details |
| US2295779A | Projection apparatus | Expired / Lapsed | 1940-08-17 | 1942-09-15 | 0 | Details |
| US2296089A | Frequency modulation receiver tuning indicator | Expired / Lapsed | 1940-02-20 | 1942-09-15 | 0 | Details |
| US2295759A | Capacitor | Expired / Lapsed | 1939-06-30 | 1942-09-15 | 0 | Details |
| US2296050A | Television circuit | Expired / Lapsed | 1938-12-30 | 1942-09-15 | 0 | Details |
| US2294372A | Phase modulation | Expired / Lapsed | 1941-10-31 | 1942-09-01 | 0 | Details |
| US2294411A | Electrical oscillator apparatus for medical purposes | Expired / Lapsed | 1938-09-21 | 1942-09-01 | 0 | Details |
| US2293835A | Noise limiter | Expired / Lapsed | 1941-04-30 | 1942-08-25 | 0 | Details |
| US2293899A | Television system | Expired / Lapsed | 1940-08-23 | 1942-08-25 | 0 | Details |
| US2294171A | Oscillation generator | Expired / Lapsed | 1940-07-12 | 1942-08-25 | 0 | Details |
| US2293839A | Centimeter wave absorber | Expired / Lapsed | 1940-06-25 | 1942-08-25 | 0 | Details |
| US2293739A | Radio direction finder | Expired / Lapsed | 1938-11-26 | 1942-08-25 | 0 | Details |
| US2293565A | Diversity receiving system | Expired / Lapsed | 1941-04-30 | 1942-08-18 | 0 | Details |
| US2293418A | Electron discharge device | Expired / Lapsed | 1940-09-27 | 1942-08-18 | 0 | Details |
| US2293528A | Separating circuit | Expired / Lapsed | 1940-05-31 | 1942-08-18 | 0 | Details |
| US2293501A | Method of and means for reducing the effects of multipath p… | Expired / Lapsed | 1940-03-15 | 1942-08-18 | 0 | Details |
| US2293166A | Radio remote control system | Expired / Lapsed | 1939-01-31 | 1942-08-18 | 0 | Details |
| US2293135A | Electronic shorting device | Expired / Lapsed | 1938-11-28 | 1942-08-18 | 0 | Details |
| US2292817A | Television system | Expired / Lapsed | 1940-07-31 | 1942-08-11 | 0 | Details |
| US2292798A | Oscillator circuit | Expired / Lapsed | 1939-07-13 | 1942-08-11 | 0 | Details |
| US2292100A | Square wave generator | Expired / Lapsed | 1940-08-30 | 1942-08-04 | 0 | Details |
| US2290992A | Diversity receiving system | Expired / Lapsed | 1940-07-27 | 1942-07-28 | 0 | Details |
| US2290775A | Stabilization of photoelectric electron multipliers | Expired / Lapsed | 1940-05-01 | 1942-07-21 | 0 | Details |
| US2290582A | Cathode ray tube | Expired / Lapsed | 1939-10-28 | 1942-07-21 | 0 | Details |
| US2289987A | Electronic keying device | Expired / Lapsed | 1940-12-28 | 1942-07-14 | 0 | Details |
| US2289988A | Electronic keying device | Expired / Lapsed | 1940-12-28 | 1942-07-14 | 0 | Details |
| US2289794A | Circuit arrangement for two-way radio telephone systems | Expired / Lapsed | 1940-11-30 | 1942-07-14 | 0 | Details |
| US2289978A | Television picture tube screen | Expired / Lapsed | 1940-11-30 | 1942-07-14 | 0 | Details |
| US2289952A | Electron gun | Expired / Lapsed | 1940-11-28 | 1942-07-14 | 0 | Details |
| US2289921A | Photosensitive electrode | Expired / Lapsed | 1940-06-01 | 1942-07-14 | 0 | Details |
| US2288766A | Radiant energy receiving device | Expired / Lapsed | 1940-07-27 | 1942-07-07 | 0 | Details |
| US2289220A | Electron discharge device | Expired / Lapsed | 1940-05-08 | 1942-07-07 | 0 | Details |
| US2289157A | Facsimile system | Expired / Lapsed | 1939-12-29 | 1942-07-07 | 0 | Details |
| US2288740A | Phase adjuster | Expired / Lapsed | 1938-10-20 | 1942-07-07 | 0 | Details |
| US2288832A | Fibrous acoustic diaphragm | Expired / Lapsed | 1937-08-31 | 1942-07-07 | 0 | Details |
| US2288402A | Television transmitting tube | Expired / Lapsed | 1941-01-29 | 1942-06-30 | 0 | Details |
| US2287862A | Transmitting system | Expired / Lapsed | 1940-12-24 | 1942-06-30 | 0 | Details |
| US2288575A | Frequency modulation | Expired / Lapsed | 1940-05-31 | 1942-06-30 | 0 | Details |
| US2287460A | Insulated heater and method of manufacture | Expired / Lapsed | 1940-11-29 | 1942-06-23 | 0 | Details |
| US2287533A | Ultra high frequency antenna feedback balancer | Expired / Lapsed | 1939-03-10 | 1942-06-23 | 0 | Details |
| US2286410A | Frequency modulation receiver tuning indicator | Expired / Lapsed | 1941-04-09 | 1942-06-16 | 0 | Details |
| US2286442A | Amplitude limiter circuit | Expired / Lapsed | 1940-12-06 | 1942-06-16 | 0 | Details |
| US2286377A | Frequency modulation receiver | Expired / Lapsed | 1940-08-31 | 1942-06-16 | 0 | Details |
| US2286280A | Electronic device | Expired / Lapsed | 1937-12-14 | 1942-06-16 | 0 | Details |
| US2286179A | Wide band antenna | Expired / Lapsed | 1940-07-10 | 1942-06-09 | 0 | Details |
| US2285684A | Remote control system | Expired / Lapsed | 1938-09-10 | 1942-06-09 | 0 | Details |
| US2285211A | Radio frequency wattmeter | Expired / Lapsed | 1940-09-28 | 1942-06-02 | 0 | Details |
| US2284873A | Navigation aiding radio beacon system | Expired / Lapsed | 1940-04-19 | 1942-06-02 | 0 | Details |
| US2284423A | Measuring instrument | Expired / Lapsed | 1940-06-01 | 1942-05-26 | 0 | Details |
| US2284101A | Impulse generator | Expired / Lapsed | 1940-02-29 | 1942-05-26 | 0 | Details |
| US2284102A | Inverse feedback amplifier | Expired / Lapsed | 1939-12-29 | 1942-05-26 | 0 | Details |
| US2284088A | Mounting piezoelectric elements | Expired / Lapsed | 1939-12-29 | 1942-05-26 | 0 | Details |
| US2284379A | Ultra high frequency voltmeter | Expired / Lapsed | 1939-12-29 | 1942-05-26 | 0 | Details |
| US2283924A | Magnetically tuned high frequency circuits | Expired / Lapsed | 1935-12-31 | 1942-05-26 | 0 | Details |
| US2282910A | Variable frequency detector system | Expired / Lapsed | 1940-10-31 | 1942-05-12 | 0 | Details |
| US2282526A | Selector for diversity receiving systems | Expired / Lapsed | 1940-06-29 | 1942-05-12 | 0 | Details |
| US2282834A | Double heterodyne receiving system | Expired / Lapsed | 1940-06-29 | 1942-05-12 | 0 | Details |
| US2282971A | Signal detecting system | Expired / Lapsed | 1939-11-30 | 1942-05-12 | 0 | Details |
| US2282092A | Frequency modulation receiver | Expired / Lapsed | 1941-03-26 | 1942-05-05 | 0 | Details |
| US2282102A | Signaling | Expired / Lapsed | 1940-12-12 | 1942-05-05 | 0 | Details |
| US2282101A | Detection of frequency modulated waves | Expired / Lapsed | 1940-10-16 | 1942-05-05 | 0 | Details |
| US2281995A | Phase comparing system | Expired / Lapsed | 1939-04-27 | 1942-05-05 | 0 | Details |
| US2280978A | Negative transconductance device | Expired / Lapsed | 1939-12-20 | 1942-04-28 | 0 | Details |
| US2281468A | Wireless receiver | Expired / Lapsed | 1939-07-22 | 1942-04-28 | 0 | Details |
| US2281196A | Radio relay repeater | Expired / Lapsed | 1939-06-30 | 1942-04-28 | 0 | Details |
| US2280282A | Electrical coupling circuits | Expired / Lapsed | 1940-11-05 | 1942-04-21 | 0 | Details |
| US2280527A | Oscillator drift compensation device | Expired / Lapsed | 1940-09-07 | 1942-04-21 | 0 | Details |
| US2280530A | Frequency modulated wave detector | Expired / Lapsed | 1940-07-17 | 1942-04-21 | 0 | Details |
| US2280525A | Frequency modulated wave detector | Expired / Lapsed | 1940-07-02 | 1942-04-21 | 0 | Details |
| US2280707A | Apparatus for and method of frequency modulating | Expired / Lapsed | 1940-05-31 | 1942-04-21 | 0 | Details |
| US2280569A | Frequency modulation receiver | Expired / Lapsed | 1940-05-04 | 1942-04-21 | 0 | Details |
| US2280733A | Deflecting circuits | Expired / Lapsed | 1939-06-30 | 1942-04-21 | 0 | Details |
| US2279506A | Frequency modulation signal detector | Expired / Lapsed | 1940-10-26 | 1942-04-14 | 0 | Details |
| US2279660A | Wave length modulation system | Expired / Lapsed | 1940-01-05 | 1942-04-14 | 0 | Details |
| US2280026A | Ultra short wave system | Expired / Lapsed | 1939-09-01 | 1942-04-14 | 0 | Details |
| US2279930A | Electronic modulator for constant frequency variable dot tr… | Expired / Lapsed | 1939-07-28 | 1942-04-14 | 0 | Details |
| US2279030A | Frequency modulation | Expired / Lapsed | 1940-05-31 | 1942-04-07 | 0 | Details |
| US2279007A | Time delay circuit and relaxation oscillator | Expired / Lapsed | 1940-03-01 | 1942-04-07 | 0 | Details |
| US2279018A | Sound recording method and system | Expired / Lapsed | 1939-12-29 | 1942-04-07 | 0 | Details |
| US2278641A | Electronic commutator | Expired / Lapsed | 1939-03-31 | 1942-04-07 | 0 | Details |
| US2276672A | Frequency modulation indicator | Expired / Lapsed | 1940-10-26 | 1942-03-17 | 0 | Details |
| US2276565A | Limiting amplifier | Expired / Lapsed | 1939-05-23 | 1942-03-17 | 0 | Details |
| US2275898A | Microfacsimile system | Expired / Lapsed | 1939-08-22 | 1942-03-10 | 0 | Details |
| US2275940A | Alarm system | Expired / Lapsed | 1939-04-22 | 1942-03-10 | 0 | Details |
| US2275974A | Sweep circuit for cathode ray tube distributors | Expired / Lapsed | 1939-02-28 | 1942-03-10 | 0 | Details |
| US2275256A | Piezometer | Expired / Lapsed | 1939-11-30 | 1942-03-03 | 0 | Details |
| US2275026A | Television system | Expired / Lapsed | 1939-10-27 | 1942-03-03 | 0 | Details |
| US2275027A | Electron discharge tubes and circuits therefor | Expired / Lapsed | 1939-07-08 | 1942-03-03 | 0 | Details |
| US2275016A | Control system | Expired / Lapsed | 1939-05-27 | 1942-03-03 | 0 | Details |
| US2274486A | Piezoelectric resonator circuit | Expired / Lapsed | 1940-05-18 | 1942-02-24 | 0 | Details |
| US2274546A | Radio compass | Expired / Lapsed | 1939-11-13 | 1942-02-24 | 0 | Details |
| US2274262A | Air speed indicator | Expired / Lapsed | 1939-05-31 | 1942-02-24 | 0 | Details |
| US2273771A | Frequency modulated carrier detector | Expired / Lapsed | 1941-04-10 | 1942-02-17 | 0 | Details |
| US2273143A | Audio volume control circuit | Expired / Lapsed | 1940-07-05 | 1942-02-17 | 0 | Details |
| US2273110A | Frequency modulated wave receiver | Expired / Lapsed | 1940-06-14 | 1942-02-17 | 0 | Details |
| US2273172A | Television system | Expired / Lapsed | 1940-02-23 | 1942-02-17 | 0 | Details |
| US2273522A | Adjustable slidable-electrode condenser | Expired / Lapsed | 1939-09-30 | 1942-02-17 | 0 | Details |
| US2273639A | Selectivity control circuit | Expired / Lapsed | 1939-06-22 | 1942-02-17 | 0 | Details |
| US2272821A | Telegraphone | Expired / Lapsed | 1939-07-28 | 1942-02-10 | 0 | Details |
| US2272431A | Directional antenna orientation control | Expired / Lapsed | 1939-06-17 | 1942-02-10 | 0 | Details |
| US2272052A | Tuning indicator system | Expired / Lapsed | 1940-10-26 | 1942-02-03 | 0 | Details |
| US2271980A | Recording of alternating current impulses | Expired / Lapsed | 1939-11-08 | 1942-02-03 | 0 | Details |
| US2271721A | Method and means for transmitting a plurality of signals ov… | Expired / Lapsed | 1939-05-03 | 1942-02-03 | 0 | Details |
| US2272062A | Coaxial line ultra high frequency amplifier | Expired / Lapsed | 1939-03-01 | 1942-02-03 | 0 | Details |
| US2271534A | Radio receiver for direction finding or course indicating s… | Expired / Lapsed | 1938-01-29 | 1942-02-03 | 0 | Details |
| US2271300A | Directive antenna | Expired / Lapsed | 1939-11-22 | 1942-01-27 | 0 | Details |
| US2270260A | Production and reproduction of sound records | Expired / Lapsed | 1937-12-24 | 1942-01-20 | 0 | Details |
| US2269599A | Telautograph system | Expired / Lapsed | 1940-12-27 | 1942-01-13 | 0 | Details |
| US2269654A | Video amplifier | Expired / Lapsed | 1940-05-22 | 1942-01-13 | 0 | Details |
| US2270012A | Distortion reducing circuits | Expired / Lapsed | 1940-03-27 | 1942-01-13 | 0 | Details |
| US2269694A | Uniform response wide band amplifier | Expired / Lapsed | 1939-10-26 | 1942-01-13 | 0 | Details |
| US2270166A | Method of making electrical connections | Expired / Lapsed | 1939-07-26 | 1942-01-13 | 0 | Details |
| US2269594A | Modulation of wire and radio transmission by frequency vari… | Expired / Lapsed | 1939-03-18 | 1942-01-13 | 0 | Details |
| US2270023A | Superheterodyne receiver | Expired / Lapsed | 1939-03-01 | 1942-01-13 | 0 | Details |
| US2268643A | Frequency modulation distance finder | Expired / Lapsed | 1939-10-25 | 1942-01-06 | 0 | Details |
| US2268792A | Radio receiver | Expired / Lapsed | 1939-01-09 | 1942-01-06 | 0 | Details |
| US2268812A | Program distribution system | Expired / Lapsed | 1939-01-04 | 1942-01-06 | 0 | Details |
| US2268085A | Radio direction finder | Expired / Lapsed | 1939-10-12 | 1941-12-30 | 0 | Details |
| US2268222A | Telegraph circuit monitoring device | Expired / Lapsed | 1938-01-28 | 1941-12-30 | 0 | Details |
| US2266517A | Automatic frequency control circuit | Expired / Lapsed | 1940-01-06 | 1941-12-16 | 0 | Details |
| US2266516A | Saw-tooth wave generator | Expired / Lapsed | 1939-03-29 | 1941-12-16 | 0 | Details |
| US2264850A | Receiving system | Expired / Lapsed | 1939-09-29 | 1941-12-02 | 0 | Details |
| US2264269A | Electron multiplier discharge device | Expired / Lapsed | 1938-07-13 | 1941-12-02 | 0 | Details |
| US2263634A | Ultra high frequency receiver | Expired / Lapsed | 1940-03-30 | 1941-11-25 | 0 | Details |
| US2263633A | Signal detecting system | Expired / Lapsed | 1940-01-31 | 1941-11-25 | 0 | Details |
| US2263669A | Radio tuning control circuits | Expired / Lapsed | 1939-04-29 | 1941-11-25 | 0 | Details |
| US2262841A | Automatic gain expansion circuit | Expired / Lapsed | 1939-10-31 | 1941-11-18 | 0 | Details |
| US2263269A | Rectifier circuit | Expired / Lapsed | 1938-05-04 | 1941-11-18 | 0 | Details |
| US2261286A | Frequency modulation detector | Expired / Lapsed | 1940-07-13 | 1941-11-04 | 0 | Details |
| US2261618A | Blocking-layer electrode system | Expired / Lapsed | 1940-01-12 | 1941-11-04 | 0 | Details |
| US2261776A | Cathode ray tube apparatus | Expired / Lapsed | 1938-12-30 | 1941-11-04 | 0 | Details |
| US2261787A | Amplifier | Expired / Lapsed | 1938-12-30 | 1941-11-04 | 0 | Details |
| US2260933A | Frequency meter | Expired / Lapsed | 1939-06-30 | 1941-10-28 | 0 | Details |
| US2260702A | Illumination determining system | Expired / Lapsed | 1939-04-14 | 1941-10-28 | 0 | Details |
| US2259511A | Microphone | Expired / Lapsed | 1938-09-30 | 1941-10-21 | 0 | Details |
| US2259395A | Lens coating | Expired / Lapsed | 1940-07-31 | 1941-10-14 | 0 | Details |
| US2259292A | Ultra short wave apparatus | Expired / Lapsed | 1939-11-17 | 1941-10-14 | 0 | Details |
| US2258752A | Saw-tooth wave generator circuit arrangement | Expired / Lapsed | 1939-10-03 | 1941-10-14 | 0 | Details |
| US2259392A | Phase modulation | Expired / Lapsed | 1939-03-18 | 1941-10-14 | 0 | Details |
| US2258943A | Synchronizing signal generator | Expired / Lapsed | 1938-11-30 | 1941-10-14 | 0 | Details |
| US2259104A | Air flow interlock | Expired / Lapsed | 1938-10-22 | 1941-10-14 | 0 | Details |
| US2258223A | Mounting of cylindrical lenses | Expired / Lapsed | 1939-11-30 | 1941-10-07 | 0 | Details |
| US2257830A | Frequency-modulated radio altimeter | Expired / Lapsed | 1939-09-01 | 1941-10-07 | 0 | Details |
| US2257094A | High frequency radio relay system | Expired / Lapsed | 1939-08-01 | 1941-09-30 | 0 | Details |
| US2257562A | Intelligence transmission system | Expired / Lapsed | 1937-03-08 | 1941-09-30 | 0 | Details |
| US2256529A | Synchronizing signal separator circuit | Expired / Lapsed | 1938-10-06 | 1941-09-23 | 0 | Details |
| US2256512A | Dual channel amplifier | Expired / Lapsed | 1937-10-22 | 1941-09-23 | 0 | Details |
| US2255757A | Audio frequency amplifier | Expired / Lapsed | 1939-07-29 | 1941-09-16 | 0 | Details |
| US2255882A | Radio frequency amplifier | Expired / Lapsed | 1938-03-30 | 1941-09-16 | 0 | Details |
| US2256462A | Television transmitting device | Expired / Lapsed | 1940-05-15 | 1941-09-09 | 0 | Details |
| US2255374A | System for noise reduction in amplifiers | Expired / Lapsed | 1939-01-27 | 1941-09-09 | 0 | Details |
| US2253867A | Diversity receiving system | Expired / Lapsed | 1940-08-23 | 1941-08-26 | 0 | Details |
| US2253832A | Signaling | Expired / Lapsed | 1939-10-14 | 1941-08-26 | 0 | Details |
| US2254022A | Electrical wave generator | Expired / Lapsed | 1939-02-24 | 1941-08-26 | 0 | Details |
| US2252770A | Light sensitive electrode and method of manufacture | Expired / Lapsed | 1940-04-30 | 1941-08-19 | 0 | Details |
| US2252058A | Method and means for testing resonant circuits | Expired / Lapsed | 1940-04-27 | 1941-08-12 | 0 | Details |
| US2252565A | Electron discharge device | Expired / Lapsed | 1940-03-09 | 1941-08-12 | 0 | Details |
| US2251992A | Picture transmitter tube | Expired / Lapsed | 1938-06-15 | 1941-08-12 | 0 | Details |
| US2252083A | Radio traffic control | Expired / Lapsed | 1938-04-23 | 1941-08-12 | 0 | Details |
| US2251786A | Television recording apparatus | Expired / Lapsed | 1938-09-30 | 1941-08-05 | 0 | Details |
| US2250578A | Transmitter control circuit | Expired / Lapsed | 1939-11-18 | 1941-07-29 | 0 | Details |
| US2250596A | Receiver output control circuit | Expired / Lapsed | 1939-07-21 | 1941-07-29 | 0 | Details |
| US2250598A | Negative feedback amplifier | Expired / Lapsed | 1939-06-22 | 1941-07-29 | 0 | Details |
| US2250819A | Variable wave generator | Expired / Lapsed | 1939-05-26 | 1941-07-29 | 0 | Details |
| US2250532A | Radio relaying system | Expired / Lapsed | 1938-10-29 | 1941-07-29 | 0 | Details |
| US2249425A | Phase and frequency modulation diversity receiving system | Expired / Lapsed | 1940-03-27 | 1941-07-15 | 0 | Details |
| US2249416A | Antenna system | Expired / Lapsed | 1939-07-29 | 1941-07-15 | 0 | Details |
| US2248442A | Frequency generator | Expired / Lapsed | 1939-06-16 | 1941-07-08 | 0 | Details |
| US2247684A | Photoelectric sorting apparatus | Expired / Lapsed | 1940-10-31 | 1941-07-01 | 0 | Details |
| US2247213A | Ultra short wave receiver | Expired / Lapsed | 1940-03-13 | 1941-06-24 | 0 | Details |
| US2246928A | Tuned circuit | Expired / Lapsed | 1939-03-22 | 1941-06-24 | 0 | Details |
| US2246696A | Oscillator system | Expired / Lapsed | 1939-01-31 | 1941-06-24 | 0 | Details |
| US2245685A | Automatic frequency control system | Expired / Lapsed | 1940-02-06 | 1941-06-17 | 0 | Details |
| US2246164A | Frequency modulator | Expired / Lapsed | 1940-01-31 | 1941-06-17 | 0 | Details |
| US2245718A | Oscillation generation | Expired / Lapsed | 1939-01-07 | 1941-06-17 | 0 | Details |
| US2245385A | Double heterodyne signal receiving system | Expired / Lapsed | 1940-02-29 | 1941-06-10 | 0 | Details |
| US2245347A | Radio remote control system | Expired / Lapsed | 1938-11-15 | 1941-06-10 | 0 | Details |
| US2244695A | Unsymmetric gain control device | Expired / Lapsed | 1938-09-29 | 1941-06-10 | 0 | Details |
| US2245353A | Gain control circuits | Expired / Lapsed | 1938-06-14 | 1941-06-10 | 0 | Details |
| US2243921A | Variable capacity device and circuit | Expired / Lapsed | 1940-01-09 | 1941-06-03 | 0 | Details |
| US2244369A | Electrical measuring and calculating device | Expired / Lapsed | 1938-10-31 | 1941-06-03 | 0 | Details |
| US2243141A | Radio receiver circuits | Expired / Lapsed | 1940-05-18 | 1941-05-27 | 0 | Details |
| US2243417A | Frequency modulation receiver | Expired / Lapsed | 1939-06-01 | 1941-05-27 | 0 | Details |
| US2243702A | Frequency monitor and detector | Expired / Lapsed | 1939-05-19 | 1941-05-27 | 0 | Details |
| US2243118A | Automatic antenna switching diversity system | Expired / Lapsed | 1939-03-15 | 1941-05-27 | 0 | Details |
| US2243414A | Frequency modulating receiver | Expired / Lapsed | 1939-02-01 | 1941-05-27 | 0 | Details |
| US2243828A | Luminescent screen | Expired / Lapsed | 1938-10-25 | 1941-05-27 | 0 | Details |
| US2242633A | Synchronizing system, particularly for television purposes | Expired / Lapsed | 1936-11-25 | 1941-05-20 | 0 | Details |
| US2241533A | Electronic circuit | Expired / Lapsed | 1938-08-31 | 1941-05-13 | 0 | Details |
| US2241544A | Visual signal recorder | Expired / Lapsed | 1938-05-18 | 1941-05-13 | 0 | Details |
| US2241027A | Electronic musical instrument | Expired / Lapsed | 1939-11-30 | 1941-05-06 | 0 | Details |
| US2239724A | Wide band antenna | Expired / Lapsed | 1938-05-18 | 1941-04-29 | 0 | Details |
| US2238117A | Ultra high frequency modulator | Expired / Lapsed | 1940-01-31 | 1941-04-15 | 0 | Details |
| US2238249A | Phase modulator | Expired / Lapsed | 1938-10-27 | 1941-04-15 | 0 | Details |
| US2238136A | Auxiliary telegraph signal transmitter | Expired / Lapsed | 1938-05-28 | 1941-04-15 | 0 | Details |
| US2237522A | Frequency modulation | Expired / Lapsed | 1939-05-12 | 1941-04-08 | 0 | Details |
| US2237896A | Electronic device | Expired / Lapsed | 1936-02-29 | 1941-04-08 | 0 | Details |
| US2236195A | Automatic cathode voltage adjusting device | Expired / Lapsed | 1938-12-15 | 1941-03-25 | 0 | Details |
| US2235565A | Tuned circuit system | Expired / Lapsed | 1939-01-07 | 1941-03-18 | 0 | Details |
| US2235755A | Error checking telegraph system | Expired / Lapsed | 1937-10-01 | 1941-03-18 | 0 | Details |
| US2235169A | Remote control system | Expired / Lapsed | 1937-05-07 | 1941-03-18 | 0 | Details |
| US2234329A | Distance determining device | Expired / Lapsed | 1939-09-29 | 1941-03-11 | 0 | Details |
| US2234293A | Antenna system | Expired / Lapsed | 1939-09-19 | 1941-03-11 | 0 | Details |
| US2234830A | Cathode ray modulator | Expired / Lapsed | 1938-05-28 | 1941-03-11 | 0 | Details |
| US2234328A | Radiant energy receiving device | Expired / Lapsed | 1937-09-24 | 1941-03-11 | 0 | Details |
| US2233786A | Fluorescent screen assembly and method of manufacture | Expired / Lapsed | 1939-11-29 | 1941-03-04 | 0 | Details |
| US2233763A | Tuning structure | Expired / Lapsed | 1939-05-27 | 1941-03-04 | 0 | Details |
| US2233778A | Automatic frequency control circuit | Expired / Lapsed | 1938-07-15 | 1941-03-04 | 0 | Details |
| US2233777A | Automatic frequency control circuit | Expired / Lapsed | 1938-07-07 | 1941-03-04 | 0 | Details |
| US2233751A | Frequency variation indicator circuit | Expired / Lapsed | 1938-01-14 | 1941-03-04 | 0 | Details |
| US2233199A | Signal detecting system | Expired / Lapsed | 1940-01-02 | 1941-02-25 | 0 | Details |
| US2233275A | Navigational instrument | Expired / Lapsed | 1939-01-31 | 1941-02-25 | 0 | Details |
| US2232900A | Electron multiplying device | Expired / Lapsed | 1938-02-15 | 1941-02-25 | 0 | Details |
| US2233126A | Device for and method of controlling high frequency currents | Expired / Lapsed | 1936-05-14 | 1941-02-25 | 0 | Details |
| US2232082A | Cable-code-to-morse-code converter | Expired / Lapsed | 1939-06-10 | 1941-02-18 | 0 | Details |
| US2232390A | Automatic frequency control | Expired / Lapsed | 1938-04-27 | 1941-02-18 | 0 | Details |
| US2231955A | Phase shifting device | Expired / Lapsed | 1938-02-25 | 1941-02-18 | 0 | Details |
| US2232044A | Television system | Expired / Lapsed | 1936-11-28 | 1941-02-18 | 0 | Details |
| US2231371A | Noise suppression circuit | Expired / Lapsed | 1939-01-04 | 1941-02-11 | 0 | Details |
| US2231697A | Electron multiplier | Expired / Lapsed | 1938-01-29 | 1941-02-11 | 0 | Details |
| US2230232A | Phase and frequency modulation | Expired / Lapsed | 1940-02-07 | 1941-02-04 | 0 | Details |
| US2230295A | Television receiver | Expired / Lapsed | 1938-08-31 | 1941-02-04 | 0 | Details |
| US2230820A | Synchronizing apparatus | Expired / Lapsed | 1938-07-26 | 1941-02-04 | 0 | Details |
| US2230231A | Phase and frequency modulation | Expired / Lapsed | 1936-10-24 | 1941-02-04 | 0 | Details |
| US2230212A | Signal receiver | Expired / Lapsed | 1940-03-09 | 1941-01-28 | 0 | Details |
| US2229752A | Electron discharge device | Expired / Lapsed | 1938-07-30 | 1941-01-28 | 0 | Details |
| US2229172A | Method of and apparatus for mounting piezoelectric crystals | Expired / Lapsed | 1938-11-28 | 1941-01-21 | 0 | Details |
| US2228883A | High speed logarithmic voltage recorder | Expired / Lapsed | 1938-03-19 | 1941-01-14 | 0 | Details |
| US2228112A | Cathode return bias circuit | Expired / Lapsed | 1938-05-07 | 1941-01-07 | 0 | Details |
| US2227054A | Film projector for television | Expired / Lapsed | 1938-10-20 | 1940-12-31 | 0 | Details |
| US2226745A | Radio frame and the like | Expired / Lapsed | 1938-10-04 | 1940-12-31 | 0 | Details |
| US2226720A | Reduction of undesired emissions of electronic discharge de… | Expired / Lapsed | 1937-05-21 | 1940-12-31 | 0 | Details |
| US2227062A | Electron discharge device | Expired / Lapsed | 1937-02-08 | 1940-12-31 | 0 | Details |
| US2226366A | Automatic volume control | Expired / Lapsed | 1938-12-30 | 1940-12-24 | 0 | Details |
| US2226214A | Transmitter | Expired / Lapsed | 1938-10-29 | 1940-12-24 | 0 | Details |
| US2226259A | Amplifier | Expired / Lapsed | 1938-08-03 | 1940-12-24 | 0 | Details |
| US2224909A | Acoustic device | Expired / Lapsed | 1939-07-27 | 1940-12-17 | 0 | Details |
| US2225044A | Method and means for reproducing infrared images | Expired / Lapsed | 1938-06-16 | 1940-12-17 | 0 | Details |
| US2223862A | Cathode alloy | Expired / Lapsed | 1939-10-31 | 1940-12-03 | 0 | Details |
| US2223431A | Means for touching up radio photographs | Expired / Lapsed | 1939-04-20 | 1940-12-03 | 0 | Details |
| US2223950A | Polarized wave transmitting system | Expired / Lapsed | 1938-09-16 | 1940-12-03 | 0 | Details |
| US2223840A | Means for indicating phase | Expired / Lapsed | 1938-04-21 | 1940-12-03 | 0 | Details |
| US2223982A | Radio system | Expired / Lapsed | 1937-01-29 | 1940-12-03 | 0 | Details |
| US2223447A | Short-wave radiotherapy system | Expired / Lapsed | 1936-07-23 | 1940-12-03 | 0 | Details |
| US2223990A | Cathode ray tube apparatus | Expired / Lapsed | 1936-03-28 | 1940-12-03 | 0 | Details |
| US2222943A | Electron switching circuit | Expired / Lapsed | 1938-04-21 | 1940-11-26 | 0 | Details |
| US2222937A | Scanning device | Expired / Lapsed | 1937-09-21 | 1940-11-26 | 0 | Details |
| US2222759A | Voltage doubling signal rectifier circuit | Expired / Lapsed | 1934-05-18 | 1940-11-26 | 0 | Details |
| US2222172A | Envelope current system | Expired / Lapsed | 1939-05-19 | 1940-11-19 | 0 | Details |
| US2222586A | Radio altimeter | Expired / Lapsed | 1939-01-28 | 1940-11-19 | 0 | Details |
| US2221115A | Multiple trace oscillograph system | Expired / Lapsed | 1937-06-30 | 1940-11-12 | 0 | Details |
| US2221541A | Gain control device | Expired / Lapsed | 1936-01-22 | 1940-11-12 | 0 | Details |
| US2220452A | Electronic device | Expired / Lapsed | 1936-12-24 | 1940-11-05 | 0 | Details |
| US2220087A | Direction finding | Expired / Lapsed | 1936-07-07 | 1940-11-05 | 0 | Details |
| US2219902A | Cathode ray tube oscillograph apparatus | Expired / Lapsed | 1935-12-19 | 1940-10-29 | 0 | Details |
| US2218914A | Multiplex receiving circuit arrangement | Expired / Lapsed | 1938-11-30 | 1940-10-22 | 0 | Details |
| US2217911A | Radio communication | Expired / Lapsed | 1938-08-12 | 1940-10-15 | 0 | Details |
| US2217279A | Acoustic apparatus | Expired / Lapsed | 1938-07-23 | 1940-10-08 | 0 | Details |
| US2216949A | Sound collecting system | Expired / Lapsed | 1937-12-31 | 1940-10-08 | 0 | Details |
| US2216232A | Over-modulation alarm device | Expired / Lapsed | 1937-11-30 | 1940-10-01 | 0 | Details |
| US2216582A | Automatic volume control with noise suppression | Expired / Lapsed | 1932-11-03 | 1940-10-01 | 0 | Details |
| US2215796A | High frequency circuit arrangement | Expired / Lapsed | 1937-04-26 | 1940-09-24 | 0 | Details |
| US2214729A | Magnetic field neutralizing system | Expired / Lapsed | 1939-08-31 | 1940-09-17 | 0 | Details |
| US2215197A | Measuring system | Expired / Lapsed | 1939-04-08 | 1940-09-17 | 0 | Details |
| US2215175A | Television synchronizing impulse separator circuit | Expired / Lapsed | 1939-02-28 | 1940-09-17 | 0 | Details |
| US2213543A | Electron discharge device | Expired / Lapsed | 1938-07-13 | 1940-09-03 | 0 | Details |
| US2212648A | Synchronizing pulse generator | Expired / Lapsed | 1939-01-28 | 1940-08-27 | 0 | Details |
| US2212206A | Electron device | Expired / Lapsed | 1937-10-21 | 1940-08-20 | 0 | Details |
| US2212447A | Synchronism correction for telegraph systems | Expired / Lapsed | 1937-10-16 | 1940-08-20 | 0 | Details |
| US2211091A | Superregenerative magnetron receiver | Expired / Lapsed | 1938-01-31 | 1940-08-13 | 0 | Details |
| US2211003A | Radio signaling system | Expired / Lapsed | 1938-01-29 | 1940-08-13 | 0 | Details |
| US2211325A | Oscillograph | Expired / Lapsed | 1935-11-26 | 1940-08-13 | 0 | Details |
| US2210394A | Regulating system | Expired / Lapsed | 1938-05-28 | 1940-08-06 | 0 | Details |
| US2209959A | Radio receiving system | Expired / Lapsed | 1938-03-31 | 1940-08-06 | 0 | Details |
| US2210487A | Wire terminal connector and block | Expired / Lapsed | 1937-10-27 | 1940-08-06 | 0 | Details |
| US2208648A | Device for measuring torsional vibration | Expired / Lapsed | 1939-05-11 | 1940-07-23 | 0 | Details |
| US2208623A | Electromechanical servo device | Expired / Lapsed | 1939-03-31 | 1940-07-23 | 0 | Details |
| US2209191A | Radio navigation device | Expired / Lapsed | 1937-10-12 | 1940-07-23 | 0 | Details |
| US2208378A | Continuously indicating radio compass | Expired / Lapsed | 1938-06-30 | 1940-07-16 | 0 | Details |
| US2207845A | Propagation of waves in a wave guide | Expired / Lapsed | 1938-05-28 | 1940-07-16 | 0 | Details |
| US2208376A | Rotating radio beacon | Expired / Lapsed | 1937-07-28 | 1940-07-16 | 0 | Details |
| US2207267A | Radio apparatus for detecting aircraft | Expired / Lapsed | 1938-07-11 | 1940-07-09 | 0 | Details |
| US2207244A | Direction finder correcting loop | Expired / Lapsed | 1937-07-29 | 1940-07-09 | 0 | Details |
| US2207540A | Method of and means for frequency comparison and measurement | Expired / Lapsed | 1937-02-01 | 1940-07-09 | 0 | Details |
| US2207249A | Recording and reproducing of sound | Expired / Lapsed | 1935-07-27 | 1940-07-09 | 0 | Details |
| US2206427A | Sound reproducing apparatus | Expired / Lapsed | 1937-03-31 | 1940-07-02 | 0 | Details |
| US2206683A | Ultra short wave attenuator and directive device | Expired / Lapsed | 1936-05-16 | 1940-07-02 | 0 | Details |
| US2205847A | Crystal filter | Expired / Lapsed | 1938-02-24 | 1940-06-25 | 0 | Details |
| US2205233A | Oscillation generation | Expired / Lapsed | 1938-06-25 | 1940-06-18 | 0 | Details |
| US2205250A | Radio and other high frequency feeder arrangements | Expired / Lapsed | 1937-04-19 | 1940-06-18 | 0 | Details |
| US2203882A | Photoamplifier system | Expired / Lapsed | 1934-12-28 | 1940-06-11 | 0 | Details |
| US2202400A | Directive signaling | Expired / Lapsed | 1937-05-06 | 1940-05-28 | 0 | Details |
| US2202390A | Television receiver | Expired / Lapsed | 1936-05-16 | 1940-05-28 | 0 | Details |
| US2201323A | Electronic modulator and method of modulation | Expired / Lapsed | 1936-04-06 | 1940-05-21 | 0 | Details |
| US2201215A | Picture transmitter tube | Expired / Lapsed | 1934-06-28 | 1940-05-21 | 0 | Details |
| US2201199A | Ultra short wave apparatus | Expired / Lapsed | 1934-04-02 | 1940-05-21 | 0 | Details |
| US2201020A | Electric indicator | Expired / Lapsed | 1937-06-30 | 1940-05-14 | 0 | Details |
| US2199634A | Secret communication system | Expired / Lapsed | 1938-06-21 | 1940-05-07 | 0 | Details |
| US2200049A | Delayed automatic volume control circuits | Expired / Lapsed | 1938-03-10 | 1940-05-07 | 0 | Details |
| US2200055A | High impedance attenuator | Expired / Lapsed | 1938-02-23 | 1940-05-07 | 0 | Details |
| US2200037A | Automatic volume control circuit | Expired / Lapsed | 1937-11-05 | 1940-05-07 | 0 | Details |
| US2200036A | Noise limiting circuit | Expired / Lapsed | 1937-11-02 | 1940-05-07 | 0 | Details |
| US2200073A | Electrical transmission system | Expired / Lapsed | 1937-09-30 | 1940-05-07 | 0 | Details |
| US2200097A | Signal translating apparatus | Expired / Lapsed | 1937-01-14 | 1940-05-07 | 0 | Details |
| US2199179A | Single channel two-way communication system | Expired / Lapsed | 1936-11-27 | 1940-04-30 | 0 | Details |
| US2198329A | Electric discharge tube | Expired / Lapsed | 1938-03-12 | 1940-04-23 | 0 | Details |
| US2198226A | Balanced diode circuit | Expired / Lapsed | 1938-02-24 | 1940-04-23 | 0 | Details |
| US2197863A | Distortion correction for television systems | Expired / Lapsed | 1937-05-29 | 1940-04-23 | 0 | Details |
| US2198445A | Device for visually indicating the deviation from a course | Expired / Lapsed | 1937-03-27 | 1940-04-23 | 0 | Details |
| US2198248A | Method of and means for communication | Expired / Lapsed | 1936-09-01 | 1940-04-23 | 0 | Details |
| US2197028A | Protective device | Expired / Lapsed | 1936-10-28 | 1940-04-16 | 0 | Details |
| US2196381A | Electrical phase reversal device | Expired / Lapsed | 1938-11-29 | 1940-04-09 | 0 | Details |
| US2196583A | Unitary optical assembly | Expired / Lapsed | 1938-05-28 | 1940-04-09 | 0 | Details |
| US2195489A | Television transmitting tube | Expired / Lapsed | 1937-10-26 | 1940-04-02 | 0 | Details |
| US2194559A | Frequency responsive relay | Expired / Lapsed | 1937-04-28 | 1940-03-26 | 0 | Details |
| US2194499A | Noise reduction system | Expired / Lapsed | 1936-07-25 | 1940-03-26 | 0 | Details |
| US2194555A | Electron discharge device amplifier | Expired / Lapsed | 1936-06-06 | 1940-03-26 | 0 | Details |
| US2193875A | System for multiplex transmission | Expired / Lapsed | 1937-08-10 | 1940-03-19 | 0 | Details |
| US2193102A | Dictograph | Expired / Lapsed | 1938-03-19 | 1940-03-12 | 0 | Details |
| US2192959A | Tone control system | Expired / Lapsed | 1937-04-30 | 1940-03-12 | 0 | Details |
| US2193079A | Method of and apparatus for measuring torsional movements | Expired / Lapsed | 1936-04-25 | 1940-03-12 | 0 | Details |
| US2192987A | Motion picture framing device | Expired / Lapsed | 1935-11-12 | 1940-03-12 | 0 | Details |
| US2192205A | Oscillation generator circuit | Expired / Lapsed | 1937-03-30 | 1940-03-05 | 0 | Details |
| US2192532A | Directive antenna | Expired / Lapsed | 1936-02-03 | 1940-03-05 | 0 | Details |
| US2192121A | Television system and the method of operation thereof | Expired / Lapsed | 1934-05-29 | 1940-02-27 | 0 | Details |
| US2191271A | Means for making impedance measurements at high radio frequ… | Expired / Lapsed | 1938-03-26 | 1940-02-20 | 0 | Details |
| US2190743A | Measuring system | Expired / Lapsed | 1936-04-07 | 1940-02-20 | 0 | Details |
| US2189988A | Photoelectric device | Expired / Lapsed | 1937-09-28 | 1940-02-13 | 0 | Details |
| US2189402A | Vacuum tube oscillator | Expired / Lapsed | 1938-06-03 | 1940-02-06 | 0 | Details |
| US2189549A | Antenna switching system | Expired / Lapsed | 1938-03-18 | 1940-02-06 | 0 | Details |
| US2189321A | Electro-optical device | Expired / Lapsed | 1937-03-04 | 1940-02-06 | 0 | Details |
| US2188611A | Impulse generator | Expired / Lapsed | 1938-06-18 | 1940-01-30 | 0 | Details |
| US2188650A | Magnetic recording | Expired / Lapsed | 1938-04-23 | 1940-01-30 | 0 | Details |
| US2188649A | Antenna | Expired / Lapsed | 1936-03-09 | 1940-01-30 | 0 | Details |
| US2188647A | Cathode ray apparatus | Expired / Lapsed | 1936-02-15 | 1940-01-30 | 0 | Details |
| US2188165A | Radio system | Expired / Lapsed | 1937-05-14 | 1940-01-23 | 0 | Details |
| US2185199A | Keying system | Expired / Lapsed | 1938-04-19 | 1940-01-02 | 0 | Details |
| US2185192A | Keying system | Expired / Lapsed | 1937-10-09 | 1940-01-02 | 0 | Details |
| US2185252A | Device for viewing photographic film | Expired / Lapsed | 1937-03-18 | 1940-01-02 | 0 | Details |
| US2185379A | Electrically controlled light valve apparatus | Expired / Lapsed | 1936-11-18 | 1940-01-02 | 0 | Details |
| US2183725A | Remote control system | Expired / Lapsed | 1937-10-23 | 1939-12-19 | 0 | Details |
| US2183147A | Printing telegraph system | Expired / Lapsed | 1936-05-07 | 1939-12-12 | 0 | Details |
| US2181871A | Concentric line tuned circuits | Expired / Lapsed | 1937-01-30 | 1939-12-05 | 0 | Details |
| US2180413A | Magnetically tuned high frequency circuits | Expired / Lapsed | 1936-11-30 | 1939-11-21 | 0 | Details |
| US2179607A | Cathode ray deflecting circuits | Expired / Lapsed | 1936-09-22 | 1939-11-14 | 0 | Details |
| US2179097A | Cathode ray tube electrode structures | Expired / Lapsed | 1938-02-10 | 1939-11-07 | 0 | Details |
| US2179277A | Modulated carrier wave receiving system | Expired / Lapsed | 1937-11-30 | 1939-11-07 | 0 | Details |
| US2179105A | Current impulse generating circuit | Expired / Lapsed | 1937-06-25 | 1939-11-07 | 0 | Details |
| US2179182A | Frequency modulation circuits | Expired / Lapsed | 1936-11-27 | 1939-11-07 | 0 | Details |
| US2179101A | Indicator | Expired / Lapsed | 1936-09-26 | 1939-11-07 | 0 | Details |
| US2178736A | Television apparatus | Expired / Lapsed | 1935-07-27 | 1939-11-07 | 0 | Details |
| US2177843A | Remote control system over power lines | Expired / Lapsed | 1937-10-09 | 1939-10-31 | 0 | Details |
| US2178237A | Aircraft landing system | Expired / Lapsed | 1937-08-18 | 1939-10-31 | 0 | Details |
| US2178244A | Optical system for sound reproducers | Expired / Lapsed | 1937-01-30 | 1939-10-31 | 0 | Details |
| US2178216A | Electroacoustical apparatus | Expired / Lapsed | 1936-06-30 | 1939-10-31 | 0 | Details |
| US2177272A | Short wave electron discharge system | Expired / Lapsed | 1936-04-22 | 1939-10-24 | 0 | Details |
| US2176653A | Two-frequency piezoelectric element | Expired / Lapsed | 1935-10-31 | 1939-10-17 | 0 | Details |
| US2176225A | Picture transmission apparatus | Expired / Lapsed | 1935-09-28 | 1939-10-17 | 0 | Details |
| US2176447A | Current supply system for radio receivers | Expired / Lapsed | 1931-11-19 | 1939-10-17 | 0 | Details |
| US2175694A | Oscillator | Expired / Lapsed | 1938-07-30 | 1939-10-10 | 0 | Details |
| US2175690A | Electron-ray tube indicating instrument | Expired / Lapsed | 1938-05-27 | 1939-10-10 | 0 | Details |
| US2175252A | Short wave antenna | Expired / Lapsed | 1937-06-12 | 1939-10-10 | 0 | Details |
| US2175270A | Reduction of noise | Expired / Lapsed | 1937-03-31 | 1939-10-10 | 0 | Details |
| US2175697A | Electron discharge amplifier | Expired / Lapsed | 1937-02-26 | 1939-10-10 | 0 | Details |
| US2175689A | Enameled mesh base electrode | Expired / Lapsed | 1936-12-10 | 1939-10-10 | 0 | Details |
| US2174701A | Ultra high frequency modulator | Expired / Lapsed | 1937-07-28 | 1939-10-03 | 0 | Details |
| US2173231A | Measuring instrument | Expired / Lapsed | 1937-06-22 | 1939-09-19 | 0 | Details |
| US2173232A | High frequency amplifier | Expired / Lapsed | 1936-12-15 | 1939-09-19 | 0 | Details |
| US2173223A | Phonograph | Expired / Lapsed | 1936-07-30 | 1939-09-19 | 0 | Details |
| US2171614A | Electrical regulating system | Expired / Lapsed | 1938-07-30 | 1939-09-05 | 0 | Details |
| US2171970A | Cathode ray tube | Expired / Lapsed | 1937-01-07 | 1939-09-05 | 0 | Details |
| US2171216A | Cathode ray electrical measuring device | Expired / Lapsed | 1938-07-01 | 1939-08-29 | 0 | Details |
| US2171219A | High frequency condenser | Expired / Lapsed | 1937-12-30 | 1939-08-29 | 0 | Details |
| US2171213A | Television transmitting tube and electrode structure | Expired / Lapsed | 1937-11-30 | 1939-08-29 | 0 | Details |
| US2171145A | Luminescent material | Expired / Lapsed | 1937-03-19 | 1939-08-29 | 0 | Details |
| US2169859A | Carrier reduced modulator | Expired / Lapsed | 1937-06-26 | 1939-08-15 | 0 | Details |
| US2169374A | Oscillation generation system | Expired / Lapsed | 1937-01-04 | 1939-08-15 | 0 | Details |
| US2168351A | Adjustable magnetic-core inductor | Expired / Lapsed | 1936-08-31 | 1939-08-08 | 0 | Details |
| US2167460A | Facsimile reproducing device | Expired / Lapsed | 1938-02-17 | 1939-07-25 | 0 | Details |
| US2166744A | Electron discharge device | Expired / Lapsed | 1938-05-28 | 1939-07-18 | 0 | Details |
| US2166688A | Television apparatus | Expired / Lapsed | 1937-12-18 | 1939-07-18 | 0 | Details |
| US2166712A | Television system | Expired / Lapsed | 1934-10-26 | 1939-07-18 | 0 | Details |
| US2165779A | Cathode ray tube support | Expired / Lapsed | 1937-06-30 | 1939-07-11 | 0 | Details |
| US2165800A | Direction control device | Expired / Lapsed | 1937-06-22 | 1939-07-11 | 0 | Details |
| US2165252A | Phase modulation receiver | Expired / Lapsed | 1937-02-10 | 1939-07-11 | 0 | Details |
| US2165256A | Radio beacon | Expired / Lapsed | 1935-03-30 | 1939-07-11 | 0 | Details |
| US2164745A | Intermediate frequency amplifier | Expired / Lapsed | 1934-10-31 | 1939-07-04 | 0 | Details |
| US2163775A | Radio frequency filter | Expired / Lapsed | 1937-04-19 | 1939-06-27 | 0 | Details |
| US2164297A | Television system | Expired / Lapsed | 1935-12-31 | 1939-06-27 | 0 | Details |
| US2163411A | Remote control system | Expired / Lapsed | 1937-10-28 | 1939-06-20 | 0 | Details |
| US2162878A | Automatic gain control circuits | Expired / Lapsed | 1937-01-26 | 1939-06-20 | 0 | Details |
| US2162827A | Oscillograph apparatus | Expired / Lapsed | 1934-12-28 | 1939-06-20 | 0 | Details |
| US2159105A | Oscillator for multiple wave band receivers | Expired / Lapsed | 1937-04-30 | 1939-05-23 | 0 | Details |
| US2159802A | Tuning indicator circuit | Expired / Lapsed | 1936-11-24 | 1939-05-23 | 0 | Details |
| US2159493A | Modulated carrier wave receiver | Expired / Lapsed | 1936-03-18 | 1939-05-23 | 0 | Details |
| US2158285A | Impulse measuring circuit | Expired / Lapsed | 1937-06-22 | 1939-05-16 | 0 | Details |
| US2157166A | Optical system | Expired / Lapsed | 1936-12-31 | 1939-05-09 | 0 | Details |
| US2157534A | Power supply system | Expired / Lapsed | 1935-09-30 | 1939-05-09 | 0 | Details |
| US2156661A | Wireless aerial | Expired / Lapsed | 1937-04-19 | 1939-05-02 | 0 | Details |
| US2156769A | Cathode ray device | Expired / Lapsed | 1935-02-28 | 1939-05-02 | 0 | Details |
| US2155492A | Radio direction finder | Expired / Lapsed | 1936-03-27 | 1939-04-25 | 0 | Details |
| US2155210A | Electrical time circuit arrangement and oscillation generat… | Expired / Lapsed | 1936-02-03 | 1939-04-18 | 0 | Details |
| US2153737A | Error detecting device for printing telegraph receivers | Expired / Lapsed | 1937-06-10 | 1939-04-11 | 0 | Details |
| US2153589A | Antenna | Expired / Lapsed | 1936-05-19 | 1939-04-11 | 0 | Details |
| US2153140A | Oscillograph | Expired / Lapsed | 1934-12-28 | 1939-04-04 | 0 | Details |
| US2150572A | Synchronous motor speed control means | Expired / Lapsed | 1936-11-28 | 1939-03-14 | 0 | Details |
| US2150573A | Electric discharge device | Expired / Lapsed | 1936-01-31 | 1939-03-14 | 0 | Details |
| US2150551A | Direction finding system | Expired / Lapsed | 1936-01-21 | 1939-03-14 | 0 | Details |
| US2149727A | Volume control system | Expired / Lapsed | 1935-03-01 | 1939-03-07 | 0 | Details |
| US2149471A | Saw-tooth wave generator | Expired / Lapsed | 1934-05-26 | 1939-03-07 | 0 | Details |
| US2148976A | Indicator and scale arrangement | Expired / Lapsed | 1938-02-15 | 1939-02-28 | 0 | Details |
| US2149080A | Current or voltage regulator | Expired / Lapsed | 1936-11-28 | 1939-02-28 | 0 | Details |
| US2149077A | Deflecting circuits | Expired / Lapsed | 1936-09-26 | 1939-02-28 | 0 | Details |
| US2146876A | Intelligence transmission system | Expired / Lapsed | 1937-01-04 | 1939-02-14 | 0 | Details |
| US2147454A | Electronic oscillator | Expired / Lapsed | 1936-12-24 | 1939-02-14 | 0 | Details |
| US2146822A | Television | Expired / Lapsed | 1932-12-15 | 1939-02-14 | 0 | Details |
| US2145372A | Detector for radio receiving systems | Expired / Lapsed | 1937-06-30 | 1939-01-31 | 0 | Details |
| US2145332A | Television system | Expired / Lapsed | 1936-01-31 | 1939-01-31 | 0 | Details |
| US2144605A | Automatic selective fading control circuit | Expired / Lapsed | 1936-12-18 | 1939-01-24 | 0 | Details |
| US2144606A | Constant bias diode detector circuit | Expired / Lapsed | 1936-12-10 | 1939-01-24 | 0 | Details |
| US2144351A | Deflecting circuit | Expired / Lapsed | 1934-10-31 | 1939-01-17 | 0 | Details |
| US2144215A | Electrical energy measuring circuit | Expired / Lapsed | 1934-04-28 | 1939-01-17 | 0 | Details |
| US2143094A | Electrical testing instrument | Expired / Lapsed | 1937-05-29 | 1939-01-10 | 0 | Details |
| US2143376A | Recording system | Expired / Lapsed | 1935-01-02 | 1939-01-10 | 0 | Details |
| US2141426A | High fidelity receiving system | Expired / Lapsed | 1936-08-29 | 1938-12-27 | 0 | Details |
| US2141756A | Multirange receiver | Expired / Lapsed | 1936-04-13 | 1938-12-27 | 0 | Details |
| US2141322A | Cascaded secondary electron emitter amplifier | Expired / Lapsed | 1935-06-25 | 1938-12-27 | 0 | Details |
| US2140004A | Electrical oscillation generator | Expired / Lapsed | 1937-01-13 | 1938-12-13 | 0 | Details |
| US2139716A | Cathode heating circuits | Expired / Lapsed | 1936-09-11 | 1938-12-13 | 0 | Details |
| US2139474A | Integration indicating circuit | Expired / Lapsed | 1936-12-23 | 1938-12-06 | 0 | Details |
| US2137304A | Piezoelectric crystal holder | Expired / Lapsed | 1936-06-19 | 1938-11-22 | 0 | Details |
| US2135028A | Recording device | Expired / Lapsed | 1936-08-29 | 1938-11-01 | 0 | Details |
| US2134562A | Signature keying device | Expired / Lapsed | 1937-04-03 | 1938-10-25 | 0 | Details |
| US2133123A | Television apparatus | Expired / Lapsed | 1935-03-08 | 1938-10-11 | 0 | Details |
| US2132655A | System for producing electrical impulses | Expired / Lapsed | 1935-02-28 | 1938-10-11 | 0 | Details |
| US2132654A | Electrical apparatus | Expired / Lapsed | 1934-10-18 | 1938-10-11 | 0 | Details |
| US2131109A | Radio telegraph receiving system | Expired / Lapsed | 1933-07-25 | 1938-09-27 | 0 | Details |
| US2130162A | Tuning indicator tube | Expired / Lapsed | 1936-05-19 | 1938-09-13 | 0 | Details |
| US2128422A | Ultrashort wave circuit | Expired / Lapsed | 1935-01-04 | 1938-08-30 | 0 | Details |
| US2125977A | Ultrahigh frequency radio system | Expired / Lapsed | 1936-07-18 | 1938-08-09 | 0 | Details |
| US2124023A | Tuning indicator and dial | Expired / Lapsed | 1936-03-28 | 1938-07-19 | 0 | Details |
| US2124029A | Frequency control line and circuit | Expired / Lapsed | 1935-06-08 | 1938-07-19 | 0 | Details |
| US2123716A | Automatic tuning control | Expired / Lapsed | 1935-04-16 | 1938-07-12 | 0 | Details |
| US2122499A | Switching device | Expired / Lapsed | 1934-09-27 | 1938-07-05 | 0 | Details |
| US2122267A | Tuning indicator circuits | Expired / Lapsed | 1937-04-30 | 1938-06-28 | 0 | Details |
| US2121877A | Ultrahigh frequency electron discharge modulator | Expired / Lapsed | 1935-12-09 | 1938-06-28 | 0 | Details |
| US2122193A | Recording and reproduction of sound | Expired / Lapsed | 1935-02-26 | 1938-06-28 | 0 | Details |
| US2121427A | Sensitivity control system for automobile radio receivers | Expired / Lapsed | 1937-04-30 | 1938-06-21 | 0 | Details |
| US2121359A | Apparatus for timing of periodic events | Expired / Lapsed | 1937-03-31 | 1938-06-21 | 0 | Details |
| US2121434A | Amplifier with oscillation producing adjustment | Expired / Lapsed | 1936-03-18 | 1938-06-21 | 0 | Details |
| US2121103A | Frequency variation response circuits | Expired / Lapsed | 1935-10-17 | 1938-06-21 | 0 | Details |
| US2119576A | Indicating dial | Expired / Lapsed | 1937-04-06 | 1938-06-07 | 0 | Details |
| US2119848A | Quartz piezoelectric element | Expired / Lapsed | 1937-02-27 | 1938-06-07 | 0 | Details |
| US2120099A | Mosaic screen structure | Expired / Lapsed | 1933-03-30 | 1938-06-07 | 0 | Details |
| US2118626A | Method and apparatus for delaying electrical impulses | Expired / Lapsed | 1936-01-28 | 1938-05-24 | 0 | Details |
| US2117664A | Automatic volume control system | Expired / Lapsed | 1935-06-29 | 1938-05-17 | 0 | Details |
| US2115858A | Harmonic reduction circuits | Expired / Lapsed | 1935-10-05 | 1938-05-03 | 0 | Details |
| US2114333A | Phase modulation | Expired / Lapsed | 1935-01-10 | 1938-04-19 | 0 | Details |
| US2114335A | Reception of phase modulated waves | Expired / Lapsed | 1931-09-25 | 1938-04-19 | 0 | Details |
| US2113212A | Reduction of noise | Expired / Lapsed | 1937-04-14 | 1938-04-05 | 0 | Details |
| US2113214A | Method of frequency or phase modulation | Expired / Lapsed | 1936-10-29 | 1938-04-05 | 0 | Details |
| US2113136A | Antenna | Expired / Lapsed | 1936-02-03 | 1938-04-05 | 0 | Details |
| US2112824A | Radio transmitter for direction finding devices | Expired / Lapsed | 1935-10-23 | 1938-04-05 | 0 | Details |
| US2113395A | Automatic fidelity control circuits | Expired / Lapsed | 1935-05-25 | 1938-04-05 | 0 | Details |
| US2113226A | Sound recording and reproducing system | Expired / Lapsed | 1935-05-08 | 1938-04-05 | 0 | Details |
| US2112826A | Alarm system | Expired / Lapsed | 1934-01-31 | 1938-04-05 | 0 | Details |
| US2113260A | Receiver | Expired / Lapsed | 1933-06-13 | 1938-04-05 | 0 | Details |
| US2112968A | Process and device for making cathodes | Expired / Lapsed | 1926-10-11 | 1938-04-05 | 0 | Details |
| US2112686A | Radio receiver | Expired / Lapsed | 1933-12-01 | 1938-03-29 | 0 | Details |
| US2112037A | Vacuum diffusion pump | Expired / Lapsed | 1937-03-27 | 1938-03-22 | 0 | Details |
| US2111710A | Filter unit | Expired / Lapsed | 1934-09-22 | 1938-03-22 | 0 | Details |
| US2111381A | Radio receiver apparatus | Expired / Lapsed | 1936-04-25 | 1938-03-15 | 0 | Details |
| US2110746A | Telemetering system | Expired / Lapsed | 1934-03-30 | 1938-03-08 | 0 | Details |
| US2110172A | Method and means for reproducing optical images at a distan… | Expired / Lapsed | 1928-02-29 | 1938-03-08 | 0 | Details |
| US2109874A | Crystal heater and regulator | Expired / Lapsed | 1936-02-01 | 1938-03-01 | 0 | Details |
| US2108152A | Electrical control apparatus | Expired / Lapsed | 1934-06-26 | 1938-02-15 | 0 | Details |
| US2108683A | Method of making fluorescent screens | Expired / Lapsed | 1934-05-23 | 1938-02-15 | 0 | Details |
| US2104075A | Radio direction finder | Expired / Lapsed | 1935-01-16 | 1938-01-04 | 0 | Details |
| US2103507A | Direction indicator | Expired / Lapsed | 1936-03-31 | 1937-12-28 | 0 | Details |
| US2103865A | Superheterodyne automatic gain control system | Expired / Lapsed | 1934-06-27 | 1937-12-28 | 0 | Details |
| US2102783A | Constant temperature apparatus | Expired / Lapsed | 1936-01-31 | 1937-12-21 | 0 | Details |
| US2102212A | Sound reproducing apparatus | Expired / Lapsed | 1935-09-30 | 1937-12-14 | 0 | Details |
| US2102166A | Velocity measuring device | Expired / Lapsed | 1933-02-25 | 1937-12-14 | 0 | Details |
| US2101135A | Temperature control container | Expired / Lapsed | 1935-08-15 | 1937-12-07 | 0 | Details |
| US2101440A | Short wave radio transmitting apparatus | Expired / Lapsed | 1935-04-09 | 1937-12-07 | 0 | Details |
| US2101520A | Oscillator for use with kinescope deflecting circuits | Expired / Lapsed | 1932-02-27 | 1937-12-07 | 0 | Details |
| US2100756A | Alternating current control | Expired / Lapsed | 1935-11-29 | 1937-11-30 | 0 | Details |
| US2100204A | Facsimile system | Expired / Lapsed | 1933-06-03 | 1937-11-23 | 0 | Details |
| US2099980A | Method and apparatus for television transmission | Expired / Lapsed | 1933-03-30 | 1937-11-23 | 0 | Details |
| US2098390A | Television transmitting apparatus | Expired / Lapsed | 1934-05-26 | 1937-11-09 | 0 | Details |
| US2098384A | Protective system | Expired / Lapsed | 1934-05-19 | 1937-11-09 | 0 | Details |
| US2097896A | Amplifying arrangement | Expired / Lapsed | 1933-11-13 | 1937-11-02 | 0 | Details |
| US2097874A | Radio receiver | Expired / Lapsed | 1933-05-18 | 1937-11-02 | 0 | Details |
| US2094733A | Automatic alarm selector | Expired / Lapsed | 1933-05-25 | 1937-10-05 | 0 | Details |
| US2095050A | Signaling | Expired / Lapsed | 1933-04-26 | 1937-10-05 | 0 | Details |
| US2093665A | Star and delta connection of impedances | Expired / Lapsed | 1934-01-27 | 1937-09-21 | 0 | Details |
| US2093095A | Automatic volume control | Expired / Lapsed | 1935-02-09 | 1937-09-14 | 0 | Details |
| US2092081A | Indicator | Expired / Lapsed | 1934-10-26 | 1937-09-07 | 0 | Details |
| US2091271A | Receiver | Expired / Lapsed | 1933-01-17 | 1937-08-31 | 0 | Details |
| US2091031A | Method of manufacturing phototubes | Expired / Lapsed | 1935-02-28 | 1937-08-24 | 0 | Details |
| US2089044A | Electron discharge tube | Expired / Lapsed | 1936-05-16 | 1937-08-03 | 0 | Details |
| US2088210A | Interstation noise suppressor circuits | Expired / Lapsed | 1933-12-16 | 1937-07-27 | 0 | Details |
| US2088198A | Electrical system | Expired / Lapsed | 1933-06-21 | 1937-07-27 | 0 | Details |
| US2087429A | Phase and frequency modulation wave receiving system | Expired / Lapsed | 1935-06-06 | 1937-07-20 | 0 | Details |
| US2087428A | Phase modulator | Expired / Lapsed | 1933-12-11 | 1937-07-20 | 0 | Details |
| US2086615A | High frequency wave meter | Expired / Lapsed | 1936-04-09 | 1937-07-13 | 0 | Details |
| US2086966A | Heat regulator | Expired / Lapsed | 1935-11-21 | 1937-07-13 | 0 | Details |
| US2086918A | Method of frequency or phase modulation | Expired / Lapsed | 1935-08-22 | 1937-07-13 | 0 | Details |
| US2086910A | Voltage regulator | Expired / Lapsed | 1934-02-08 | 1937-07-13 | 0 | Details |
| US2085418A | Variable terminal impedance signaling system | Expired / Lapsed | 1933-12-27 | 1937-06-29 | 0 | Details |
| US2085406A | Electrical device | Expired / Lapsed | 1933-08-31 | 1937-06-29 | 0 | Details |
| US2084760A | System for radio spectrography | Expired / Lapsed | 1934-04-10 | 1937-06-22 | 0 | Details |
| US2084186A | Photocell amplifier | Expired / Lapsed | 1934-02-01 | 1937-06-15 | 0 | Details |
| US2082517A | Thermionic valve amplifier | Expired / Lapsed | 1935-06-07 | 1937-06-01 | 0 | Details |
| US2082042A | Radio system | Expired / Lapsed | 1934-04-26 | 1937-06-01 | 0 | Details |
| US2081690A | Device for the measuring and comparing of electrical impeda… | Expired / Lapsed | 1933-07-22 | 1937-05-25 | 0 | Details |
| US2081577A | Phase modulation | Expired / Lapsed | 1932-01-23 | 1937-05-25 | 0 | Details |
| US2078908A | Combined multiband electrical structure and switching mecha… | Expired / Lapsed | 1934-03-28 | 1937-04-27 | 0 | Details |
| US2078302A | Modulating system for short waves | Expired / Lapsed | 1933-08-31 | 1937-04-27 | 0 | Details |
| US2077401A | Directive control system | Expired / Lapsed | 1936-04-30 | 1937-04-20 | 0 | Details |
| US2077223A | Modulation system | Expired / Lapsed | 1935-05-14 | 1937-04-13 | 0 | Details |
| US2076168A | Quenching oscillator for superregenerative receivers | Expired / Lapsed | 1935-10-31 | 1937-04-06 | 0 | Details |
| US2074496A | Television deflecting circuits | Expired / Lapsed | 1934-08-24 | 1937-03-23 | 0 | Details |
| US2073643A | Ultrashort wave modulated carrier wave radio communication … | Expired / Lapsed | 1935-12-31 | 1937-03-16 | 0 | Details |
| US2073933A | Radio frequency distribution system | Expired / Lapsed | 1931-04-04 | 1937-03-16 | 0 | Details |
| US2073409A | Signaling system | Expired / Lapsed | 1934-07-18 | 1937-03-09 | 0 | Details |
| US2073370A | Television system | Expired / Lapsed | 1932-11-01 | 1937-03-09 | 0 | Details |
| US2072278A | Voltage multiplier circuit | Expired / Lapsed | 1933-05-09 | 1937-03-02 | 0 | Details |
| US2071933A | Alarm system | Expired / Lapsed | 1931-02-28 | 1937-02-23 | 0 | Details |
| US2071113A | Detection of frequency modulated signals | Expired / Lapsed | 1935-10-17 | 1937-02-16 | 0 | Details |
| US2069813A | Fading elimination | Expired / Lapsed | 1936-02-10 | 1937-02-09 | 0 | Details |
| US2069809A | Automatic volume control circuit | Expired / Lapsed | 1932-11-10 | 1937-02-09 | 0 | Details |
| US2069631A | Apparatus for recording and reproducing sound | Expired / Lapsed | 1929-10-10 | 1937-02-02 | 0 | Details |
| US2068112A | Amplification and selectivity control circuit | Expired / Lapsed | 1935-08-20 | 1937-01-19 | 0 | Details |
| US2067432A | Radio communication | Expired / Lapsed | 1928-12-05 | 1937-01-12 | 0 | Details |
| US2065758A | Light responsive device | Expired / Lapsed | 1935-03-08 | 1936-12-29 | 0 | Details |
| US2066027A | Constant frequency generator | Expired / Lapsed | 1933-04-18 | 1936-12-29 | 0 | Details |
| US2065565A | Automatic frequency control system | Expired / Lapsed | 1932-06-13 | 1936-12-29 | 0 | Details |
| US2066048A | Television system | Expired / Lapsed | 1931-09-24 | 1936-12-29 | 0 | Details |
| US2066284A | Variable mu amplifier circuit | Expired / Lapsed | 1931-07-18 | 1936-12-29 | 0 | Details |
| US2064582A | Radio apparatus | Expired / Lapsed | 1934-10-31 | 1936-12-15 | 0 | Details |
| US2064469A | Device for and method of controlling high frequency currents | Expired / Lapsed | 1933-10-23 | 1936-12-15 | 0 | Details |
| US2064289A | Frequency control system | Expired / Lapsed | 1930-09-22 | 1936-12-15 | 0 | Details |
| US2063588A | Phase or amplitude modulated wave demodulator | Expired / Lapsed | 1934-03-20 | 1936-12-08 | 0 | Details |
| US2063248A | Frequency changer | Expired / Lapsed | 1927-05-05 | 1936-12-08 | 0 | Details |
| US2061734A | Signaling system | Expired / Lapsed | 1934-09-29 | 1936-11-24 | 0 | Details |
| US2060977A | Photoelectric device | Expired / Lapsed | 1931-10-28 | 1936-11-17 | 0 | Details |
| US2060025A | Vibrator power supply system | Expired / Lapsed | 1935-02-01 | 1936-11-10 | 0 | Details |
| US2060611A | Receiving system | Expired / Lapsed | 1933-12-23 | 1936-11-10 | 0 | Details |
| US2060592A | Oscillation generator | Expired / Lapsed | 1933-09-27 | 1936-11-10 | 0 | Details |
| US2058512A | Radio receiver | Expired / Lapsed | 1935-05-11 | 1936-10-27 | 0 | Details |
| US2056607A | Sound and television receiver | Expired / Lapsed | 1934-06-28 | 1936-10-06 | 0 | Details |
| US2056392A | Photoelectric apparatus and method of operating the same | Expired / Lapsed | 1932-11-19 | 1936-10-06 | 0 | Details |
| US2055513A | Facsimile system | Expired / Lapsed | 1932-03-24 | 1936-09-29 | 0 | Details |
| US2055883A | Aircraft altimeter | Expired / Lapsed | 1932-01-18 | 1936-09-29 | 0 | Details |
| US2055090A | Electrical oscillation generator | Expired / Lapsed | 1934-02-17 | 1936-09-22 | 0 | Details |
| US2053787A | Thermionic oscillation generator | Expired / Lapsed | 1934-02-21 | 1936-09-08 | 0 | Details |
| US2052700A | Terminal construction | Expired / Lapsed | 1932-02-04 | 1936-09-01 | 0 | Details |
| US2050059A | Relay system | Expired / Lapsed | 1934-03-01 | 1936-08-04 | 0 | Details |
| US2049647A | Gas discharge relay | Expired / Lapsed | 1932-10-15 | 1936-08-04 | 0 | Details |
| US2045542A | Combined noise suppresser and tuning indicator | Expired / Lapsed | 1933-08-05 | 1936-06-23 | 0 | Details |
| US2045107A | Phase modulation | Expired / Lapsed | 1932-12-02 | 1936-06-23 | 0 | Details |
| US2043997A | Television system | Expired / Lapsed | 1930-08-14 | 1936-06-16 | 0 | Details |
| US2043582A | Radio receiver | Expired / Lapsed | 1934-01-30 | 1936-06-09 | 0 | Details |
| US2042302A | Radio relaying system | Expired / Lapsed | 1935-01-10 | 1936-05-26 | 0 | Details |
| US2040530A | Electron discharge device | Expired / Lapsed | 1933-11-04 | 1936-05-12 | 0 | Details |
| US2040813A | Television system | Expired / Lapsed | 1932-09-30 | 1936-05-12 | 0 | Details |
| US2039923A | Superheterodyne receiver | Expired / Lapsed | 1934-12-04 | 1936-05-05 | 0 | Details |
| US2038539A | Antenna | Expired / Lapsed | 1933-12-16 | 1936-04-28 | 0 | Details |
| US2037799A | Ultrahigh frequency device | Expired / Lapsed | 1934-02-28 | 1936-04-21 | 0 | Details |
| US2034738A | Radio telegraph repeater | Expired / Lapsed | 1932-10-31 | 1936-03-24 | 0 | Details |
| US2034565A | Cathode ray tube noise gate system | Expired / Lapsed | 1934-09-25 | 1936-03-17 | 0 | Details |
| US2033231A | Modulation system | Expired / Lapsed | 1931-09-19 | 1936-03-10 | 0 | Details |
| US2032199A | Energizing circuits for space discharge devices | Expired / Lapsed | 1933-06-19 | 1936-02-25 | 0 | Details |
| US2031100A | Oscillation generator | Expired / Lapsed | 1934-09-10 | 1936-02-18 | 0 | Details |
| US2031224A | Thermionic oscillation generator | Expired / Lapsed | 1933-11-17 | 1936-02-18 | 0 | Details |
| US2031198A | Photophone | Expired / Lapsed | 1933-04-22 | 1936-02-18 | 0 | Details |
| US2030120A | Superregenerative receiving system | Expired / Lapsed | 1933-04-19 | 1936-02-11 | 0 | Details |
| US2028857A | Electrical communication system | Expired / Lapsed | 1932-02-27 | 1936-01-28 | 0 | Details |
| US2027530A | Navigational guide system | Expired / Lapsed | 1932-11-15 | 1936-01-14 | 0 | Details |
| US2027975A | Frequency modulation | Expired / Lapsed | 1930-06-25 | 1936-01-14 | 0 | Details |
| US2026758A | Secret signaling | Expired / Lapsed | 1932-12-21 | 1936-01-07 | 0 | Details |
| US2026944A | Means for receiving and amplifying electric signals | Expired / Lapsed | 1929-10-01 | 1936-01-07 | 0 | Details |
| US2024489A | Circuit arrangement for generating or amplifying electric o… | Expired / Lapsed | 1933-01-14 | 1935-12-17 | 0 | Details |
| US2022805A | Radio receiver | Expired / Lapsed | 1933-11-13 | 1935-12-03 | 0 | Details |
| US2021907A | Method of and apparatus for producing images of objects | Expired / Lapsed | 1931-11-13 | 1935-11-26 | 0 | Details |
| US2022406A | Protective device in amplifier circuit | Expired / Lapsed | 1931-07-07 | 1935-11-26 | 0 | Details |
| US2020813A | Centralized radio system | Expired / Lapsed | 1933-07-17 | 1935-11-12 | 0 | Details |
| US2020377A | Band pass circuit | Expired / Lapsed | 1930-10-17 | 1935-11-12 | 0 | Details |
| US2019446A | Phase and amplitude modulation receiver | Expired / Lapsed | 1934-04-09 | 1935-10-29 | 0 | Details |
| US2017897A | Luminescent tube for wave indication | Expired / Lapsed | 1932-03-31 | 1935-10-22 | 0 | Details |
| US2017886A | Duo-signaling system | Expired / Lapsed | 1932-03-21 | 1935-10-22 | 0 | Details |
| US2018314A | Multiple discharge tube | Expired / Lapsed | 1929-12-07 | 1935-10-22 | 0 | Details |
| US2018348A | Means for controlling the terminal pressure of an electric … | Expired / Lapsed | 1929-06-20 | 1935-10-22 | 0 | Details |
| US2017153A | Sound reproducing system | Expired / Lapsed | 1932-11-10 | 1935-10-15 | 0 | Details |
| US2017192A | Electrical network | Expired / Lapsed | 1932-10-29 | 1935-10-15 | 0 | Details |
| US2017278A | Glow discharge device | Expired / Lapsed | 1930-08-23 | 1935-10-15 | 0 | Details |
| US2014518A | Remote control system | Expired / Lapsed | 1933-06-23 | 1935-09-17 | 0 | Details |
| US2014102A | Direct reading vacuum tube meter | Expired / Lapsed | 1934-05-29 | 1935-09-10 | 0 | Details |
| US2013594A | Indicating device | Expired / Lapsed | 1930-07-16 | 1935-09-03 | 0 | Details |
| US2012410A | Head rest reproducer | Expired / Lapsed | 1932-06-17 | 1935-08-27 | 0 | Details |
| US2012710A | Variable condenser | Expired / Lapsed | 1931-10-16 | 1935-08-27 | 0 | Details |
| US2011942A | Ultra short wave receiver | Expired / Lapsed | 1932-01-16 | 1935-08-20 | 0 | Details |
| US2007099A | Modulation | Expired / Lapsed | 1932-09-16 | 1935-07-02 | 0 | Details |
| US2006052A | Amplifier | Expired / Lapsed | 1933-09-30 | 1935-06-25 | 0 | Details |
| US2005111A | Amplifier | Expired / Lapsed | 1931-04-09 | 1935-06-18 | 0 | Details |
| US2004126A | Antenna selector | Expired / Lapsed | 1928-11-16 | 1935-06-11 | 0 | Details |
| US2004107A | Radio receiving system | Expired / Lapsed | 1928-02-20 | 1935-06-11 | 0 | Details |
| US2003329A | High speed keying | Expired / Lapsed | 1931-11-05 | 1935-06-04 | 0 | Details |
| US2002151A | Photographic printing apparatus and method for endless soun… | Expired / Lapsed | 1932-02-19 | 1935-05-21 | 0 | Details |
| US2001217A | Means for compensating for temperature changes in piezo-ele… | Expired / Lapsed | 1933-07-21 | 1935-05-14 | 0 | Details |
| US1999721A | Method of and means for recording sound | Expired / Lapsed | 1931-06-04 | 1935-04-30 | 0 | Details |
| US1999884A | Frequency multiplication | Expired / Lapsed | 1930-12-26 | 1935-04-30 | 0 | Details |
| US1999176A | Method and means for signaling by frequency fluctuation | Expired / Lapsed | 1928-01-28 | 1935-04-30 | 0 | Details |
| US1994534A | Inductance coil and method of manufacture thereof | Expired / Lapsed | 1933-04-19 | 1935-03-19 | 0 | Details |
| US1993395A | Signal generator | Expired / Lapsed | 1932-03-10 | 1935-03-05 | 0 | Details |
| US1992625A | Frequency controlling system | Expired / Lapsed | 1933-09-29 | 1935-02-26 | 0 | Details |
| US1989954A | Electric discharge tube | Expired / Lapsed | 1931-11-09 | 1935-02-05 | 0 | Details |
| US1989965A | Method of testing recorded sound | Expired / Lapsed | 1931-08-05 | 1935-02-05 | 0 | Details |
| US1988090A | Thermionic modulation system | Expired / Lapsed | 1932-09-26 | 1935-01-15 | 0 | Details |
| US1987969A | Process for the manufacture of high resistances | Expired / Lapsed | 1928-05-05 | 1935-01-15 | 0 | Details |
| US1987406A | Talking motion picture projector | Expired / Lapsed | 1929-09-12 | 1935-01-08 | 0 | Details |
| US1987587A | Electrical device and method of determining distances | Expired / Lapsed | 1928-01-16 | 1935-01-08 | 0 | Details |
| US1984545A | Method of and means for comparing alternating current volta… | Expired / Lapsed | 1932-12-30 | 1934-12-18 | 0 | Details |
| US1983715A | Modulation | Expired / Lapsed | 1931-10-22 | 1934-12-11 | 0 | Details |
| US1979484A | Communication system | Expired / Lapsed | 1932-04-13 | 1934-11-06 | 0 | Details |
| US1977997A | Control system | Expired / Lapsed | 1931-04-25 | 1934-10-23 | 0 | Details |
| US1975928A | Method and means for making sound records | Expired / Lapsed | 1929-09-28 | 1934-10-09 | 0 | Details |
| US1975929A | Sound record and method of making the same | Expired / Lapsed | 1929-09-28 | 1934-10-09 | 0 | Details |
| US1974184A | Radio apparatus | Expired / Lapsed | 1931-03-04 | 1934-09-18 | 0 | Details |
| US1973303A | Oscillation generator | Expired / Lapsed | 1932-05-25 | 1934-09-11 | 0 | Details |
| US1968104A | Amplifying system | Expired / Lapsed | 1929-07-08 | 1934-07-31 | 0 | Details |
| US1964189A | Directive antenna | Expired / Lapsed | 1928-09-11 | 1934-06-26 | 0 | Details |
| US1961170A | Recording the wave-length to which a radio set is tuned | Expired / Lapsed | 1929-11-07 | 1934-06-05 | 0 | Details |
| US1960090A | Light controlling apparatus | Expired / Lapsed | 1930-05-15 | 1934-05-22 | 0 | Details |
| US1958994A | High frequency transmitter | Expired / Lapsed | 1931-12-01 | 1934-05-15 | 0 | Details |
| US1958996A | Optical system for sound reproducers | Expired / Lapsed | 1931-11-28 | 1934-05-15 | 0 | Details |
| US1959010A | Screen grid tube circuit | Expired / Lapsed | 1930-06-28 | 1934-05-15 | 0 | Details |
| US1959044A | Electrooptical system | Expired / Lapsed | 1930-01-03 | 1934-05-15 | 0 | Details |
| US1957949A | Antenna | Expired / Lapsed | 1929-07-11 | 1934-05-08 | 0 | Details |
| US1955899A | Method and system for communication by television | Expired / Lapsed | 1930-09-25 | 1934-04-24 | 0 | Details |
| US1954947A | Electrooptical method and apparatus | Expired / Lapsed | 1931-03-04 | 1934-04-17 | 0 | Details |
| US1955558A | Time alarm | Expired / Lapsed | 1930-07-23 | 1934-04-17 | 0 | Details |
| US1949840A | Sound reproducing method | Expired / Lapsed | 1930-02-17 | 1934-03-06 | 0 | Details |
| US1946088A | Condensing lens system for motion picture projection | Expired / Lapsed | 1930-07-24 | 1934-02-06 | 0 | Details |
| US1944119A | Convertible band pass receiver | Expired / Lapsed | 1930-05-27 | 1934-01-16 | 0 | Details |
| US1941001A | Recorder | Expired / Lapsed | 1929-01-19 | 1933-12-26 | 0 | Details |
| US1937754A | Telephony | Expired / Lapsed | 1929-11-18 | 1933-12-05 | 0 | Details |
| US1932232A | Radio receiving set | Expired / Lapsed | 1931-04-23 | 1933-10-24 | 0 | Details |
| US1926807A | Impedance transformer | Expired / Lapsed | 1928-04-14 | 1933-09-12 | 0 | Details |
| US1922674A | Insulation in electric discharge tubes | Expired / Lapsed | 1928-04-24 | 1933-08-15 | 0 | Details |
| US1921852A | Light controlling method and means | Expired / Lapsed | 1928-10-25 | 1933-08-08 | 0 | Details |
| US1917291A | Method and means for eliminating fading | Expired / Lapsed | 1928-05-02 | 1933-07-11 | 0 | Details |
| US1915934A | Glow discharge tube | Expired / Lapsed | 1930-04-16 | 1933-06-27 | 0 | Details |
| US1909940A | Dynatron receiver | Expired / Lapsed | 1931-10-17 | 1933-05-23 | 0 | Details |
| US1908320A | Piezo-electric crystal holder | Expired / Lapsed | 1929-12-09 | 1933-05-09 | 0 | Details |
| US1907965A | Automatic tuning | Expired / Lapsed | 1927-11-01 | 1933-05-09 | 0 | Details |
| US1901642A | Signaling | Expired / Lapsed | 1929-12-23 | 1933-03-14 | 0 | Details |
| US1901033A | Method of recording and reproducing phonofilms | Expired / Lapsed | 1929-04-24 | 1933-03-14 | 0 | Details |
| US1899684A | Radio apparatus | Expired / Lapsed | 1931-01-16 | 1933-02-28 | 0 | Details |
| US1899021A | Glow lamp circuit | Expired / Lapsed | 1929-12-21 | 1933-02-28 | 0 | Details |
| US1899503A | Electromechanical vibrator | Expired / Lapsed | 1927-05-05 | 1933-02-28 | 0 | Details |
| US1898040A | Production of sound and sound picture record | Expired / Lapsed | 1931-09-15 | 1933-02-21 | 0 | Details |
| US1898180A | Coupling arrangement | Expired / Lapsed | 1927-09-21 | 1933-02-21 | 0 | Details |
| US1897204A | Means for the remote reading of instruments | Expired / Lapsed | 1927-02-26 | 1933-02-14 | 0 | Details |
| US1895902A | Screen-grid amplifier | Expired / Lapsed | 1929-08-29 | 1933-01-31 | 0 | Details |
| US1885604A | Instantaneous control of light | Expired / Lapsed | 1925-06-02 | 1932-11-01 | 0 | Details |
| US1879138A | Method of and means for controlling light | Expired / Lapsed | 1928-10-25 | 1932-09-27 | 0 | Details |
| US1876109A | Device for modulating the frequency of electric oscillations | Expired / Lapsed | 1929-11-20 | 1932-09-06 | 0 | Details |
| US1873786A | Selective channeling system | Expired / Lapsed | 1928-09-29 | 1932-08-23 | 0 | Details |
| US1873785A | Tube commutator | Expired / Lapsed | 1928-04-11 | 1932-08-23 | 0 | Details |
| US1869556A | Method and means for vibrating crystals | Expired / Lapsed | 1928-01-20 | 1932-08-02 | 0 | Details |
| US1867177A | Loud speaker | Expired / Lapsed | 1930-01-03 | 1932-07-12 | 0 | Details |
| US1867171A | Tone stabilizing | Expired / Lapsed | 1929-02-26 | 1932-07-12 | 0 | Details |
| US1867139A | Radioreceiving apparatus | Expired / Lapsed | 1927-03-30 | 1932-07-12 | 0 | Details |
| US1860529A | Electromechanical system | Expired / Lapsed | 1930-04-12 | 1932-05-31 | 0 | Details |
| US1859782A | Acoustic diaphragm | Expired / Lapsed | 1929-06-11 | 1932-05-24 | 0 | Details |
| US1853678A | Method of and means for separating desired from undesired e… | Expired / Lapsed | 1926-06-05 | 1932-04-12 | 0 | Details |
| US1849884A | Side band selector receiver | Expired / Lapsed | 1928-11-19 | 1932-03-15 | 0 | Details |
| US1844950A | Automatic transmitter | Expired / Lapsed | 1929-05-21 | 1932-02-16 | 0 | Details |
| US1844199A | Pyro-recording paper | Expired / Lapsed | 1928-08-30 | 1932-02-09 | 0 | Details |
| US1844014A | Acoustic instrument | Expired / Lapsed | 1928-07-13 | 1932-02-09 | 0 | Details |
| US1831640A | Tuned radio frequency coupling device | Expired / Lapsed | 1928-02-13 | 1931-11-10 | 0 | Details |
| US1825441A | Sound recording process and apparatus | Expired / Lapsed | 1921-01-08 | 1931-09-29 | 0 | Details |
| US1822000A | Automatic tape transmitter | Expired / Lapsed | 1929-03-27 | 1931-09-08 | 0 | Details |
| US1819692A | Variable condenser | Expired / Lapsed | 1923-01-09 | 1931-08-18 | 0 | Details |
| US1811895A | Light control system | Expired / Lapsed | 1928-10-31 | 1931-06-30 | 0 | Details |
| US1802745A | Dot multiplex | Expired / Lapsed | 1928-09-29 | 1931-04-28 | 0 | Details |
| US1784150A | Amplifier of electrical currents | Expired / Lapsed | 1923-06-22 | 1930-12-09 | 0 | Details |
| US1771700A | Method of and apparatus for multiplex signaling | Expired / Lapsed | 1925-01-08 | 1930-07-29 | 0 | Details |
| US1761118A | Radio signaling system | Expired / Lapsed | 1924-11-06 | 1930-06-03 | 0 | Details |
| US1757333A | Frequency trap for radio signaling apparatus | Expired / Lapsed | 1922-08-31 | 1930-05-06 | 0 | Details |
| US1754293A | Phonograph adjunct for radio sets | Expired / Lapsed | 1925-06-02 | 1930-04-15 | 0 | Details |
| US1751584A | Picture transmission | Expired / Lapsed | 1927-08-13 | 1930-03-25 | 0 | Details |
| US1748386A | Electric discharge tube | Expired / Lapsed | 1926-11-04 | 1930-02-25 | 0 | Details |
| US1745342A | Directive-projecting system of electric waves | Expired / Lapsed | 1926-09-03 | 1930-01-28 | 0 | Details |
| US1742773A | Radio signaling system | Expired / Lapsed | 1928-01-05 | 1930-01-07 | 0 | Details |
| US1737277A | Variable-capacity apparatus | Expired / Lapsed | 1925-02-28 | 1929-11-26 | 0 | Details |
| US1732029A | Acoustic instrument | Expired / Lapsed | 1925-07-01 | 1929-10-15 | 0 | Details |
| US1717712A | Resistor and method of making same | Expired / Lapsed | 1927-01-17 | 1929-06-18 | 0 | Details |
| US1694646A | Wireless telegraph receiver | Expired / Lapsed | 1919-06-25 | 1928-12-11 | 0 | Details |
| US1693806A | Electromechanical system | Expired / Lapsed | 1925-02-28 | 1928-12-04 | 0 | Details |
| US1678973A | Signal-monitoring system | Expired / Lapsed | 1926-01-25 | 1928-07-31 | 0 | Details |
| US1677806A | Electric phonograph circuit | Expired / Lapsed | 1925-07-21 | 1928-07-17 | 0 | Details |
| US1675334A | Electron device | Expired / Lapsed | 1922-06-09 | 1928-07-03 | 0 | Details |
| US1667497A | Phase shifter | Expired / Lapsed | 1923-08-27 | 1928-04-24 | 0 | Details |
| US1642526A | Means for supplying power to thermionic valves | Expired / Lapsed | 1926-08-17 | 1927-09-13 | 0 | Details |
| US1629685A | Wireless telephony | Expired / Lapsed | 1920-12-18 | 1927-05-24 | 0 | Details |
| US1615098A | Arrangement for feeding vacuum tubes | Expired / Lapsed | 1922-09-30 | 1927-01-18 | 0 | Details |
| US1571405A | Apparatus for wave changing in radiosignaling | Expired / Lapsed | 1919-07-31 | 1926-02-02 | 0 | Details |
| US1564627A | Wireless telegraph and telephone transmission | Expired / Lapsed | 1920-03-31 | 1925-12-08 | 0 | Details |
| US1550571A | Receiving system for wireless telegraphy and telephony | Expired / Lapsed | 1920-03-31 | 1925-08-18 | 0 | Details |
| US1517654A | Wireless signaling system | Expired / Lapsed | 1921-03-30 | 1924-12-02 | 0 | Details |
| US1441029A | Transmitter for telephony | Expired / Lapsed | 1920-03-31 | 1923-01-02 | 0 | Details |
| US1432354A | Radiosignaling apparatus | Expired / Lapsed | 1921-03-30 | 1922-10-17 | 0 | Details |