Patent US3619486A successfully refreshed from Google Patents.
US3619486A
Expired / Lapsed
US
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Matrix amplifier for developing push-pull color control signals
Assignee: Zenith Electronics LLC
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Filing: 1969-08-26
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Granted: 1971-11-09
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Expires: 1989-08-26
Abstract
Abstract A monolithic structure includes three transistorized differential amplifiers having a common bias network so that they all conduct the same amount of current. An additional pair of transistors connects with each of those amplifiers in cascode fashion and a color-difference signal is applied to one side of each differential amplifier while the luminance signal is applied to the opposite side with such polarity that push-pull primary color signals are developed at the outputs of the cascode circuits for application to a color picture tube. Retrace blanking pulses are applied along with the luminance signal to accomplish retrace blockout.
Inventors
- 👤 George J Tzakis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:26
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/67
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
231 words
A matrix amplifier for developing push-pull color control signals from the luminance and three color-difference signals collectively representing a color image which comprises: three differential amplifiers individually including a pair of transistor devices having collector, base and emitter electrodes, and a constant current source arranged in a Y-type circuit configuration with said current source included in the collector-emitter paths of both of said transistor devices; common bias means for establishing the same current flow in said current source of each of said amplifiers; means for applying said luminance signal to said base electrode of one of said pair of transistor devices of each of said amplifiers; means for applying said color-difference signals to the other of said pair of transistor devices of said amplifiers, respectively, the polarities of said signals, as applied to said devices, being related to develop at said collectors of said pair of transistor devices of said amplifiers push-pull control signals representing the three color fields, respectively, of the image being translated; and two additional transistors included in each of said differential amplifiers having base, collector and emitter electrodes with their collector-emitter paths connected in series with the collector-emitter paths of said pair of transistor devices, respectively, and with their base electrodes maintained at a fixed reference potential to define with said transistor devices cascode amplifiers for deriving said push-pull control signals for application to a color-image reproducer.
Claim 2
Dependent Claim
231 words
A matrix amplifier for developing push-pull color control signals from the luminance and three color-difference signals collectively representing a color image which comprises: three differential amplifiers individually including a pair of transistor devices having collector, base and emitter electrodes, and a constant current source arranged in a Y-type circuit configuration with said current source included in the collector-emitter paths of both of said transistor devices; common bias means for establishing the same current flow in said current source of each of said amplifiers; means for applying said luminance signal to said base electrode of one of said pair of transistor devices of each of said amplifiers; means for applying said color-difference signals to the other of said pair of transistor devices of said amplifiers, respectively, the polarities of said signals, as applied to said devices, being related to develop at said collectors of said pair of transistor devices of said amplifiers push-pull control signals representing the three color fields, respectively, of the image being translated; and two additional transistors included in each of said differential amplifiers having base, collector and emitter electrodes with their collector-emitter paths connected in series with the collector-emitter paths of said pair of transistor devices, respectively, and with their base electrodes maintained at a fixed reference potential to define with said transistor devices cascode amplifiers for deriving said push-pull control signals for application to a color-image reproducer.
Claim 3
Dependent Claim
69 words
A matrix amplifier in accordance with claim 1 in which at least one of said cascode amplifiers includes a collector load across which one of said control signals is developed, and in which a pair of unidirectionally conductive control devices are connected in parallel across said collector load with such polarity that a given signal variation developed in said load affects the conductivity of said devices in opposite senses.
Claim 4
Dependent Claim
33 words
A matrix amplifier in accordance with claim 2 in which said conductive control devices comprise a pair of transistors connected to define complementary symmetry type of emitter followers coupled to said collector load.
Claim 5
Dependent Claim
61 words
A matrix amplifier in accordance with claim 3 which is a monolithic structure; in which said means for deriving said push-pull control signals comprises a pair of output connections in each of said amplifiers; and in which said monolithic structure further comprises means for establishing a substantially constant predetermined DC potential difference between said output connections of each of said amplifiers.
Claim 6
Dependent Claim
37 words
A matrix amplifier in accordance with claim 4 in which said means for establishing a DC potential difference comprises in each amplifier a Zener diode connected to one of the complementary symmetry types of emitter followers thereof.
Claim 7
Dependent Claim
56 words
A matrix amplifier in accordance with claim 4 which further comprises means for applying to at least one of said pair of transistor devices of each of said amplifiers a periodically recurring retrace signal of such polarity as to introduce retrace blanking components into said push-pull control signals to blank said image reproducer during retrace intervals.
Claim 8
Dependent Claim
29 words
A matrix amplifier in accordance with claim 6 in which said retrace signal is applied to the one of said pair of transistor devices that receives said luminance signal.
Claim 9
Dependent Claim
56 words
A matrix amplifier in accordance with claim 3 in which the base electrodes of the transistors constituting each complementary symmetry emitter follower are connected together by a biasing network including a pair of diodes for biasing said transistors to incipient conduction; and in which the emitters of said transistors are interconnected by a current limiting impedance.
Claim 10
Dependent Claim
49 words
A matrix amplifier in accordance with claim 7 in which said means for applying said luminance signal to said differential amplifiers comprises three voltage dividers connected to said amplifiers, respectively, and relatively adjustable for tracking purposes, and in which said retrace signal is also applied through said voltage dividers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |