Patent US2868511A successfully refreshed from Google Patents.
Patent US3513343A successfully refreshed from Google Patents.
US3129288A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency modulation receiver
Assignee: Zenith Electronics LLC
•
Filing: 1962-09-10
•
Granted: 1964-04-14
•
Expires: 1982-09-10
Abstract
No abstract record available.
Inventors
- 👤 Vries Adrian J De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:11
CPC Classifications
H; H03; H03D; H03D1/00; H03D1/22; H03D1/2209; H03D1/2227; H03D3/00; H03D3/02; H03D3/06; H03D3/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
179 words
A RECEIVER FOR USING A STEREOPHONIC PROGRAM COMPRISING A CARRIER FREQUENCY-MODULATED IN ACCORDANCE WITH THE SUM OF TWO AUDIO SIGNALS AND ALSO IN ACCORDANCE WITH A SUBCARRIER SIGNAL WHICH HAS BEEN SUPPRESSED-CARRIER AMPLITUDE-MODULATED WITH THE DIFFERENCE OF SAID TWO AUDIO SIGNALS, SAID RECEIVER COMPRISING: A FREQUENCY-MODULATION DETECTOR RESPONSIVE TO SAID CARRIER FOR DERIVING A COMPOSITE SIGNAL REPRESENTING THE MODULATION OF SAID CARRIER; AN AMPLITUDE-MODULATION DETECTOR INCLUDING AT LEAST ONE TRANSISTOR HAVING THREE ELECTRODES, A DECTING CIRCUIT COMPRISING ONE PAIR OF SAID ELECTRODES, AND A PHASE-REVERSING CIRCUIT COUPLED TO SAID DETECTING CIRCUIT AND COMPRISING ANOTHER PAIR OF SAID ELECTRODES FOR REVERSING THE POLARITY OF THE DETECTED SIGNAL DEVELOPED IN SAID DETECTING CIRCUIT; MEANS FOR APPLYING TO SAID AMPLITUDE-MODULATION DETECTOR A DEMODULATION SIGNAL CORRESPONDING TO THE CARRIER COMPONENT OF SAID SUBCARRIER SIGNAL AND SAID COMPOSITE SIGNAL TO DEVELOP IN SAID PHASE-REVERSING CIRCUIT A COMBINATION OF SAID AUDIO SIGNALS; AND MEANS FOR APPLYING SAID COMPOSITE SIGNAL TO SAID PHASE-REVERSING CIRCUIT TO MATRIX WITH SAID COMBINATION OF SAID AUDIO SIGNALS AND DERIVE A PARTICULAR ONE OF SAID AUDIO SIGNALS SEPARATED FROM THE OTHER.
Claim 2
Dependent Claim
179 words
A RECEIVER FOR USING A STEREOPHONIC PROGRAM COMPRISING A CARRIER FREQUENCY-MODULATED IN ACCORDANCE WITH THE SUM OF TWO AUDIO SIGNALS AND ALSO IN ACCORDANCE WITH A SUBCARRIER SIGNAL WHICH HAS BEEN SUPPRESSED-CARRIER AMPLITUDE-MODULATED WITH THE DIFFERENCE OF SAID TWO AUDIO SIGNALS, SAID RECEIVER COMPRISING: A FREQUENCY-MODULATION DETECTOR RESPONSIVE TO SAID CARRIER FOR DERIVING A COMPOSITE SIGNAL REPRESENTING THE MODULATION OF SAID CARRIER; AN AMPLITUDE-MODULATION DETECTOR INCLUDING AT LEAST ONE TRANSISTOR HAVING THREE ELECTRODES, A DECTING CIRCUIT COMPRISING ONE PAIR OF SAID ELECTRODES, AND A PHASE-REVERSING CIRCUIT COUPLED TO SAID DETECTING CIRCUIT AND COMPRISING ANOTHER PAIR OF SAID ELECTRODES FOR REVERSING THE POLARITY OF THE DETECTED SIGNAL DEVELOPED IN SAID DETECTING CIRCUIT; MEANS FOR APPLYING TO SAID AMPLITUDE-MODULATION DETECTOR A DEMODULATION SIGNAL CORRESPONDING TO THE CARRIER COMPONENT OF SAID SUBCARRIER SIGNAL AND SAID COMPOSITE SIGNAL TO DEVELOP IN SAID PHASE-REVERSING CIRCUIT A COMBINATION OF SAID AUDIO SIGNALS; AND MEANS FOR APPLYING SAID COMPOSITE SIGNAL TO SAID PHASE-REVERSING CIRCUIT TO MATRIX WITH SAID COMBINATION OF SAID AUDIO SIGNALS AND DERIVE A PARTICULAR ONE OF SAID AUDIO SIGNALS SEPARATED FROM THE OTHER.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-04-14 | 1967-10-14 | 1968-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-04-14 | 1971-10-14 | 1972-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-04-14 | 1975-10-14 | 1976-04-14 | $7700.00 | Window Closed / Lapsed |