Patent US4170023A successfully refreshed from Google Patents.
US4170023A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carrier agc circuit, especially burst acc and apc
Assignee: Sony Corp
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Filing: 1978-06-13
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Granted: 1979-10-02
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Expires: 1998-06-13
Abstract
Abstract A burst signal level detecting circuit for an automatic color control (ACC) circuit of a television receiver includes a band pass amplifier through which an input chrominance signal is supplied to a first and a second phase comparator via a burst gate. A subtracted output of the first and second phase comparators is supplied to a voltage controlled oscillator (VCO) and, the output of the VCO is supplied to the first phase comparator and through a phase shifter to the second phase comparator. An added output of the first and second phase comparators is supplied to the band pass amplifier as an ACC signal for controlling the gain of the band pass amplifier.
Inventors
- 👤 Akira Yamakoshi
- 👤 Takao Tsuchiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:16
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3036; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/085; H03L7/087; H04; H04N; H04N9/00; H04N9/44; H04N9/455; H04N9/64; H04N9/68
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
203 words
A burst signal level detecting circuit for an automatic color control circuit of a television receiver, comprising: a first phase comparator having an output; a second phase comparator having output; means for supplying an input signal to said first and second comparators; subtracting means receiving said output of said first phase comparator and said output of said second phase comparator for producing an output corresponding to the difference between said outputs from said respective comparators; a variable frequency oscillator controlled by said output of said subtracting means and supplying an output thereof to said first phase comparator, so that said output of said first phase comparator corresponds to the phase relation of said output of said oscillator and said input signal; a phase shifter supplied with the output of said variable frequency oscillator and having a phase-shifted output signal thereof supplied to said second phase comparator, so that said output of said second phase comparator corresponds to the phase relation of said phase-shifted output signal and said input signal; and adding means supplied with the output of said first phase comparator and the output of said second phase comparator to produce an added output signal proportional to the level of said input signal.
Claim 2
Dependent Claim
203 words
A burst signal level detecting circuit for an automatic color control circuit of a television receiver, comprising: a first phase comparator having an output; a second phase comparator having output; means for supplying an input signal to said first and second comparators; subtracting means receiving said output of said first phase comparator and said output of said second phase comparator for producing an output corresponding to the difference between said outputs from said respective comparators; a variable frequency oscillator controlled by said output of said subtracting means and supplying an output thereof to said first phase comparator, so that said output of said first phase comparator corresponds to the phase relation of said output of said oscillator and said input signal; a phase shifter supplied with the output of said variable frequency oscillator and having a phase-shifted output signal thereof supplied to said second phase comparator, so that said output of said second phase comparator corresponds to the phase relation of said phase-shifted output signal and said input signal; and adding means supplied with the output of said first phase comparator and the output of said second phase comparator to produce an added output signal proportional to the level of said input signal.
Claim 3
Dependent Claim
27 words
A burst signal level detecting circuit according to claim 1; wherein said phase-shifted output signal is phase-shifted by π12 from said output of said variable frequency oscillator.
Claim 4
Dependent Claim
35 words
A burst signal level detecting circuit according to claim 1; wherein said means for supplying an input signal to said comparators includes a burst gate circuit for providing a burst signal as said input signal.
Claim 5
Dependent Claim
58 words
A burst signal level detecting circuit according to claim 3; including a band pass amplifier connected to the input of said burst gate circuit for supplying an amplified chrominance signal thereto, and wherein the level of said amplified chrominance signal does not substantially change due to variations in the phase of said output signal from said variable oscillator.
Claim 6
Dependent Claim
36 words
A burst signal level detecting circuit according to claim 4; wherein said output signal from said adding means is a voltage signal which is supplied to said band pass amplifier as a gain control signal therefor.
Claim 7
Dependent Claim
258 words
An automatic gain control circuit comprising: a gain controlled amplifier supplied with an input signal having a predetermined carrier frequency and producing an amplified output signal corresponding to said input signal; a first and a second phase comparator, each having a first and second input terminal and an output terminal having an output thereat; means for supplying said amplified output signal from said gain controlled amplifier to the first terminals of said first and second phase comparators; subtracting means connected to the output terminals of said first and second phase comparators for producing an output corresponding to the difference between said outputs from said respective comparators; a variable oscillator controlled by said output of said subtracting means and having an output signal thereof supplied to the second input terminal of said first phase comparator, so that said first phase comparator provides said output thereof in correspondence to the phase relation of said output signal of said oscillator and said amplified output signal; a phase shifter supplied with the output of said oscillator and having a phase-shifted output signal thereof supplied to the second input terminal of said second phase comparator, so that said second phase comparator provides said output thereof in correspondence to the phase relation of said phase-shifted output signal and said amplified output signal; and adding means connected to the output terminals of said first and second phase comparators and having an added output which is supplied as a gain control signal to said gain controlled amplifier for producing a stable output signal of said amplifier.
Claim 8
Dependent Claim
258 words
An automatic gain control circuit comprising: a gain controlled amplifier supplied with an input signal having a predetermined carrier frequency and producing an amplified output signal corresponding to said input signal; a first and a second phase comparator, each having a first and second input terminal and an output terminal having an output thereat; means for supplying said amplified output signal from said gain controlled amplifier to the first terminals of said first and second phase comparators; subtracting means connected to the output terminals of said first and second phase comparators for producing an output corresponding to the difference between said outputs from said respective comparators; a variable oscillator controlled by said output of said subtracting means and having an output signal thereof supplied to the second input terminal of said first phase comparator, so that said first phase comparator provides said output thereof in correspondence to the phase relation of said output signal of said oscillator and said amplified output signal; a phase shifter supplied with the output of said oscillator and having a phase-shifted output signal thereof supplied to the second input terminal of said second phase comparator, so that said second phase comparator provides said output thereof in correspondence to the phase relation of said phase-shifted output signal and said amplified output signal; and adding means connected to the output terminals of said first and second phase comparators and having an added output which is supplied as a gain control signal to said gain controlled amplifier for producing a stable output signal of said amplifier.
Claim 9
Dependent Claim
27 words
An automatic gain control circuit according to claim 6; wherein said input signal is a chrominance signal and said gain controlled amplifier is a band pass amplifier.
Claim 10
Dependent Claim
18 words
An automatic gain control circuit according to claim 6; wherein said variable oscillator is a variable frequency oscillator.
Claim 11
Dependent Claim
18 words
An automatic gain control circuit according to claim 6; wherein said variable oscillator is a variable phase oscillator.
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) | 1982-10-01 | 1983-04-02 | 1983-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-01 | 1987-04-02 | 1987-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-01 | 1991-04-02 | 1991-10-02 | $7700.00 | Window Closed / Lapsed |