US3702374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color video signal recording and reproducing apparatus with pilot signal for automatic color control
Assignee: Sony Corp
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Filing: 1970-04-13
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Granted: 1972-11-07
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Expires: 1990-04-13
Abstract
Abstract In a color video signal recording and reproducing apparatus that records and reproduces a pilot signal along with the color video signal, so that any amplitude fluctuating component of the reproduced chrominance signal resulting from the recording and reproducing operations has its counterpart or corresponding variation in the pilot signal, the reproduced modulated chrominance signal and pilot signal are mixed to provide a mixed signal which is subjected to amplitude control, the pilot signal is separated from the amplitude-controlled mixed signal, variations in the pilot signal thus separated are detected, and such detected variations are employed for determining the amplitude control exerted on the mixed signal, whereby to diminish undesired variations in the chrominance signal derived from the amplitude-controlled mixed signal.
Inventors
- 👤 Toshihiko Numakura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:23
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/793; H04N9/80; H04N9/82; H04N9/83
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
189 words
In a color video signal recording and reproducing apparatus; the combination of means for reproducing a recorded combined signal constituted by a carrier frequency-modulated with a luminance signal to form a luminance component, carriers amplitude-modulated with a chrominance signal and frequencyconverted to a band substantially below that of said frequencymodulated luminance signal to form a chrominance component and a continuous pilot signal having a frequency adjacent that of the frequency-converted carriers of the chrominance signal so as to be similarly subjected to level variations during the recording and reproducing of said combined signal, means providing a mixed signal of the chrominance component and pilot signal separated from the reproduced combined signal, amplitude control means receiving said mixed signal for controlling the amplitude of said mixed signal, means for separating the pilot signal from the amplitude-controlled mixed signal, means for detecting the separated pilot signal and producing a control signal in dependence on variations thereof, and means applying said control signal to said amplitude control means so as to cause the latter to diminish undesirable variations in said chrominance component resulting from the recording and reproducing of said combined signal.
Claim 2
Dependent Claim
189 words
In a color video signal recording and reproducing apparatus; the combination of means for reproducing a recorded combined signal constituted by a carrier frequency-modulated with a luminance signal to form a luminance component, carriers amplitude-modulated with a chrominance signal and frequencyconverted to a band substantially below that of said frequencymodulated luminance signal to form a chrominance component and a continuous pilot signal having a frequency adjacent that of the frequency-converted carriers of the chrominance signal so as to be similarly subjected to level variations during the recording and reproducing of said combined signal, means providing a mixed signal of the chrominance component and pilot signal separated from the reproduced combined signal, amplitude control means receiving said mixed signal for controlling the amplitude of said mixed signal, means for separating the pilot signal from the amplitude-controlled mixed signal, means for detecting the separated pilot signal and producing a control signal in dependence on variations thereof, and means applying said control signal to said amplitude control means so as to cause the latter to diminish undesirable variations in said chrominance component resulting from the recording and reproducing of said combined signal.
Claim 3
Dependent Claim
52 words
A color video signal and recording apparatus according to claim 1, in which said means providing said mixed signal includes means separately extracting said chrominance component and said pilot signal from said reproduced combined signal, and mixer circuit means receiving the extracted chrominance component and pilot signal at respective input terminals thereof.
Claim 4
Dependent Claim
28 words
A color video signal recording and reproducing apparatus according to claim 1, in which filter means are provided for separating said chrominance component from the amplitude-controlled mixed signal.
Claim 5
Dependent Claim
28 words
A color video signal recording and reproducing apparatus according to claim 1, in whicH filter means are provided for separating said control signal from the detected pilot signal.
Claim 6
Dependent Claim
56 words
A color video signal and recording apparatus according to claim 1, in which filter means are provided to extract said luminance component from the reproduced combined signal, and limiting means receive the extracted luminance component for eliminating excessive fluctuations in the level of said luminance component resulting from the recording and reproducing of said combined signal.
Claim 7
Dependent Claim
94 words
A color video signal recording and reproducing apparatus according to claim 5, further comprising demodulating means demodulating the limited luminance component from said limiting means to provide said luminance signal, filter means to extract the amplitude-controlled chrominance component from the amplitude-controlled mixed signal, frequency converting means to return the frequency of said carriers of the chrominance component to that of said chrominance signal, and synthesizer circuit means to combine the demodulated luminance component with the frequency-converted, amplitude-controlled chrominance component and thereby to reconstitute the color video signal comprised of said luminance and chrominance signals.
Claim 8
Dependent Claim
85 words
A color video signal recording and reproducing apparatus according to claim 6, in which said frequency converting means includes means to frequency multiply said pilot signal extracted from the reproduced combined signal, oscillator means having an output at the frequency of said carriers of the chrominance signal prior to the frequency conversion thereof, and means to beat up the frequency of said amplitude-controlled chrominance component with said multiplied pilot signal and the output of said oscillator means to avoid phase variations in said chrominance signals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-07 | 1976-05-08 | 1976-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-07 | 1980-05-08 | 1980-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-07 | 1984-05-08 | 1984-11-07 | $7700.00 | Window Closed / Lapsed |