Patent US4379999A successfully refreshed from Google Patents.
Patent US3660596A successfully refreshed from Google Patents.
US3660596A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recording and reproducing system for color video signal
Assignee: Sony Corp
•
Filing: 1970-05-15
•
Granted: 1972-05-02
•
Expires: 1990-05-15
Abstract
Abstract A composite color video signal may be magnetically recorded by separating the luminance and chrominance signals, frequencymodulating the luminance signal on a carrier, and frequencyshifting the chrominance signal such that the bands of the frequency-modulated luminance signal and the frequency-converted chrominance signal do not overlap. The two signals are then combined and magnetically recorded with the frequency-converted chrominance signal amplitude modulating the frequency-modulated luminance signal. To avoid a beat interference between a harmonic, particularly the second harmonic of the carrier of the frequency-converted chrominance signal and the luminance signal, there is provided a compensation signal which is an integral multiple of the frequency of the carrier of the frequencyconverted chrominance signal, and which is phase-shifted with respect to said carrier so that, when the compensation signal is added to the luminance signal either before frequency-modulation in the recording operation, or after demodulation of the frequency-modulated luminance signal in the reproducing operation, the described beat interference is avoided. By avoiding the beat interference the amplitude of the frequencyconverted chrominance signal relative to the amplitude of the frequency-modulated luminance signal, as recorded, can be made large with resulting good signal-to-noise ratio of the reproduced chrominance signal.
Inventors
- 👤 Toshihiko Numakura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:45
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/7908; H04N9/7912
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
183 words
In a system for recording and reproducing a composite color video signal consisting of a luminance signal and a chrominance signal and which comprises recording and reproducing portions: said recording portion having means for frequency-modulating the luminance signal, means for frequency-converting the chrominance signal, means for combining the frequency-modulated luminance signal and the frequency-converted chrominance signal, and means for recording the combined signal on a magnetic media; said reproducing portion having means for reproducing said combined signal from the magnetic media, means for extracting the frequency-modulated luminance signal and the frequencyconverted chrominance signal from the reproduced combined signal, means for demodulating the frequency-modulated luminance signal, and means for reconverting said frequencyconverted chrominance signal; one of said portions of said system further having means producing a compensation signal at a frequency which is an integral multiple of the carrier frequency of the frequencyconverted chrominance signal and with said compensation signal having a predetermined phase with respect to said carrier; and means for combining said compensation signal with the luminance signal in the respective portion of said system so as to avoid a beat interference.
Claim 2
Dependent Claim
183 words
In a system for recording and reproducing a composite color video signal consisting of a luminance signal and a chrominance signal and which comprises recording and reproducing portions: said recording portion having means for frequency-modulating the luminance signal, means for frequency-converting the chrominance signal, means for combining the frequency-modulated luminance signal and the frequency-converted chrominance signal, and means for recording the combined signal on a magnetic media; said reproducing portion having means for reproducing said combined signal from the magnetic media, means for extracting the frequency-modulated luminance signal and the frequencyconverted chrominance signal from the reproduced combined signal, means for demodulating the frequency-modulated luminance signal, and means for reconverting said frequencyconverted chrominance signal; one of said portions of said system further having means producing a compensation signal at a frequency which is an integral multiple of the carrier frequency of the frequencyconverted chrominance signal and with said compensation signal having a predetermined phase with respect to said carrier; and means for combining said compensation signal with the luminance signal in the respective portion of said system so as to avoid a beat interference.
Claim 3
Dependent Claim
28 words
A system according to claim 1, wherein said frequency of the compensation signal is the same as the second harmonic of said carrier of the frequency-converted chrominance signal.
Claim 4
Dependent Claim
16 words
A system according to claim 1, wherein said compensation signal is produced in the recording portion.
Claim 5
Dependent Claim
22 words
A system according to claim 3, wherein said compensation signal has the same frequency as said carrier of the frequency-converted chromiNance signal.
Claim 6
Dependent Claim
19 words
A system according to claim 1, wherein said compensation signal is produced in said reproducing portion of the system.
Claim 7
Independent Claim
125 words
A system for recording a composite color video signal consisting of a luminance signal and a chrominance signal, and which comprises means for extracting said luminance signal and said chrominance signal from said composite signal, means for frequency-modulating said luminance signal, means for frequency-converting said chrominance signal, means for producing a compensation signal at a frequency which is an integral multiple of the carrier frequency of the frequency-converted chrominance signal and with said compensation signal having a predetermined phase with respect to said carrier, means for combining said compensation signal with said luminance signal in advance of the frequency-modulation thereof, means for combining said frequency-modulated luminance signal having the compensation signal with said frequency-converted chrominance signal, and means for magnetically recording the resulting combined signal.
Claim 8
Independent Claim
125 words
A system for recording a composite color video signal consisting of a luminance signal and a chrominance signal, and which comprises means for extracting said luminance signal and said chrominance signal from said composite signal, means for frequency-modulating said luminance signal, means for frequency-converting said chrominance signal, means for producing a compensation signal at a frequency which is an integral multiple of the carrier frequency of the frequency-converted chrominance signal and with said compensation signal having a predetermined phase with respect to said carrier, means for combining said compensation signal with said luminance signal in advance of the frequency-modulation thereof, means for combining said frequency-modulated luminance signal having the compensation signal with said frequency-converted chrominance signal, and means for magnetically recording the resulting combined signal.
Claim 9
Dependent Claim
26 words
A system according to claim 6, wherein the frequency of said compensation signal is the second harmonic of the carrier frequency of said frequency-converted chrominance signal.
Claim 10
Dependent Claim
25 words
A system according to claim 7, in which said frequency-modulated luminance signal is utilized as a bias signal for said frequency-converted chrominance signal during recording.
Claim 11
Dependent Claim
27 words
A system according to claim 7, in which the level of said compensation signal is proportional to the square of the level of said frequency-converted chrominance signal.
Claim 12
Dependent Claim
23 words
A system according to claim 6, in which said compensation signal has the same frequency as said carrier of the frequency-converted chrominance signal.
Claim 13
Independent Claim
163 words
A system for reproducing a color video signal from a magnetically recorded combined signal containing a frequency-modulated luminance signal and a frequency-converted chrominance signal, and which comprises: means for magnetically reproducing said combined signal, means for extracting said frequency-modulated luminance signal and frequency-converted chrominance signal from the reproduced combined signal, means for demodulating the luminance signal, means for reconverting the chrominance signal, means for producing a compensation signal from the frequency-converted chrominance signal with the frequency thereof being an integral multiple of carrier frequency of the frequency-converted chrominance signal and with the phase of said compensation signal being predetermined with respect to said carrier, means for combining said compensation signal with the demodulated luminance signal so as to avoid beat interference by cancelling an harmonic of the carrier of said frequency-converted chrominance signal which appears in the demodulated luminance signal, and means for combining said demodulated luminance signal with said reconverted chrominance signal so as to substantially reconstitute the composite color video signal.
Claim 14
Independent Claim
163 words
A system for reproducing a color video signal from a magnetically recorded combined signal containing a frequency-modulated luminance signal and a frequency-converted chrominance signal, and which comprises: means for magnetically reproducing said combined signal, means for extracting said frequency-modulated luminance signal and frequency-converted chrominance signal from the reproduced combined signal, means for demodulating the luminance signal, means for reconverting the chrominance signal, means for producing a compensation signal from the frequency-converted chrominance signal with the frequency thereof being an integral multiple of carrier frequency of the frequency-converted chrominance signal and with the phase of said compensation signal being predetermined with respect to said carrier, means for combining said compensation signal with the demodulated luminance signal so as to avoid beat interference by cancelling an harmonic of the carrier of said frequency-converted chrominance signal which appears in the demodulated luminance signal, and means for combining said demodulated luminance signal with said reconverted chrominance signal so as to substantially reconstitute the composite color video signal.
Claim 15
Dependent Claim
26 words
A system according to claim 11, in which said frequency of the compensation signal is the second harmonic of said carrier of the frequency-converted chrominance signal.
Claim 16
Dependent Claim
26 words
A system according to claim 12, in which said compensation signal has a level proportional to the square of the level of the frequency-converted chrominance signal.
Claim 17
Dependent Claim
131 words
In the recording and reproducing of a combined signal derived from a color video signal composed of a luminance signal and a chrominance signal, and in which said luminance signal is frequency-modulated and said chrominance signal is frequency-converted and combined with said frequency-modulated luminance signal to provide said combined signal which is recorded and reproduced; the method of avoiding beat interference of a harmonic of the carrier of said frequency-converted chrominance signal with said luminance signal comprising producing a compensation signal at a frequency which is an integral multiple of thE frequency of said carrier of the frequency-converted chrominance signal and with the phase of said compensation signal being predetermined with respect to said carrier, and combining said compensation signal with said luminance signal so as to avoid said heat interference.
Claim 18
Dependent Claim
131 words
In the recording and reproducing of a combined signal derived from a color video signal composed of a luminance signal and a chrominance signal, and in which said luminance signal is frequency-modulated and said chrominance signal is frequency-converted and combined with said frequency-modulated luminance signal to provide said combined signal which is recorded and reproduced; the method of avoiding beat interference of a harmonic of the carrier of said frequency-converted chrominance signal with said luminance signal comprising producing a compensation signal at a frequency which is an integral multiple of thE frequency of said carrier of the frequency-converted chrominance signal and with the phase of said compensation signal being predetermined with respect to said carrier, and combining said compensation signal with said luminance signal so as to avoid said heat interference.
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) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |