US4264918A
Expired / Lapsed
US
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Automatic chroma gain control circuits useful in secam coders
Assignee: RCA Licensing Corp
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Filing: 1979-11-19
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Granted: 1981-04-28
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Expires: 1999-11-19
Abstract
Abstract A method and circuit for controlling the gain of a SECAM camera inserts a test signal into a channel. The resulting deviation is measured and used to control the gain of the channel.
Inventors
- 👤 Felix Aschwanden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:38
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/68; H04N11/00; H04N11/06; H04N11/18; H04N11/183
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
48 words
A method of controlling the gain of SECAM chroma channel having a frequency modulator, said method comprising inserting a test signal into said channel, measuring the resulting frequency deviation due to said test signal, and automatically controlling the gain of said channel in accordance with the resulting deviation.
Claim 2
Independent Claim
48 words
A method of controlling the gain of SECAM chroma channel having a frequency modulator, said method comprising inserting a test signal into said channel, measuring the resulting frequency deviation due to said test signal, and automatically controlling the gain of said channel in accordance with the resulting deviation.
Claim 3
Dependent Claim
18 words
A method as claimed in claim 1, wherein said test signal is inserted during the vertical blanking interval.
Claim 4
Dependent Claim
48 words
A method as claimed in claim 1, wherein said measuring step comprises frequency dividing the deviated signal to provide a signal to be measured, providing time reference pulses, coincidence detecting said signal to be measured and said time reference pulses, and integrating resultant signal of said detecting step.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 1, wherein said controlling step comprises applying a control signal to a multiplier.
Claim 6
Dependent Claim
15 words
A method as claimed in claim 1 wherein said controlling step comprises shunting said channel.
Claim 7
Independent Claim
48 words
A device comprising a SECAM chroma channel having a frequency modulator, means for inserting a test signal into said channel, means for measuring the resulting frequency deviation due to said test signal, and means for automatically controlling the gain of said channel in accordance with the resulting deviation.
Claim 8
Independent Claim
48 words
A device comprising a SECAM chroma channel having a frequency modulator, means for inserting a test signal into said channel, means for measuring the resulting frequency deviation due to said test signal, and means for automatically controlling the gain of said channel in accordance with the resulting deviation.
Claim 9
Dependent Claim
20 words
A device as claimed in claim 6, wherein said inserting means inserts said test signal during the vertical blanking time.
Claim 10
Dependent Claim
62 words
A device as claimed in claim 6, wherein measuring means comprises a divider-decoder for dividing the deviated signal to produce a signal to be measured, a reference divider for dividing a reference signal to produce time reference pulses, a coincidence detector coupled to receive said time reference pulses and said signal to be measured, and an integrator coupled to the coincidence detector.
Claim 11
Dependent Claim
20 words
A device as claimed in claim 6, wherein said gain control means comprises a linear multiplier disposed in said channel.
Claim 12
Dependent Claim
16 words
A device as claimed in claim 6, wherein said gain control means comprises a shunting element.
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) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |