Patent US3588341A successfully refreshed from Google Patents.
US3588341A
Expired / Lapsed
US
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Automatic brightness control circuit for establishing the black level of signals in a television reciver
Assignee: Motorola Solutions Inc
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Filing: 1969-04-01
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Granted: 1971-06-28
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Expires: 1989-04-01
Abstract
Abstract IN AN AUTOMATIC BRIGHTNESS CONTROL CIRCUIT FOR A COLOR TELEVISION RECEIVER USING DIRECT DEMODULATION OF THE COLOR AND BRIGHTNESS SIGNALS, THE SIGNALS PRESENT ON THE BASE AND EMITTER OF THE GREEN NPN OUTPUT TRANSISTOR AMPLIFIER ARE COMPARED BY CONNECTING THEM ACROSS THE BASE-EMITTER PATH OF A PNP TRANSISTOR, AND WHENEVER THE NPN TRAMSISTOR IS CUT OFF, INDICATIVE OF A BLACK LEVEL SIGNALS, THE PNP COMPARISON TRAMSISTOR IS RENDERED CONDUCTIVE. THE COLLECTOR OF THE COMPARISON TRANSISTOR IS CONNECTED THROUGH AN INTEGRATING CIRCUIT, THE OUTPUT OF WHICH IS USED TO VARY THE DC OPERATING LEVELS OF THE THREE DRIVER AMPLIFIERS IN A CLOSED LOOP CONTROL SYSTEM.
Inventors
- 👤 Robert B Hansen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:39
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/44; H04N5/57
Claims Analysis
Total Claims: 0
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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) | 1974-06-27 | 1974-12-27 | 1975-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-27 | 1978-12-27 | 1979-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-27 | 1982-12-27 | 1983-06-28 | $7700.00 | Window Closed / Lapsed |