US3820154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phased color under video recording and playback method and apparatus
Assignee: INT VIDEO CORP
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Filing: 1972-08-25
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Granted: 1974-06-25
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Expires: 1992-08-25
Abstract
Abstract An improved ''''color under'''' video recording and playback system which provides a phased color composite video signal having a wide band luminance component. In playback, the long term time base variations experienced by the lower frequency luminance information are introduced into the frequency shifted chroma and high frequency luminance information, which frequency shifted chroma and high frequency luminance information experiences less phase variations due to its lower recording frequency. The output signal has stable chroma for excellent color fidelity and stable high frequency luminance for excellent edge definition. Low frequency luminance information contains some uncorrected time base error which is not visible if the tape transport is within certain practical limits of stability relative to short term TBE''s. A cancellation or interlace technique reduces synchronous distortion from the shifted color subcarrier.
Inventors
- 👤 Y Faroudja
- 👤 L Kowal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:00
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/87; H04N9/898; H04N9/80; H04N9/82; H04N9/83
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
131 words
A method of recovering a composite color video signal from a reproduced color under type video signal comprising filtering out the shifted chroma spectrum and demodulating the modulated carrier component of the color under type video signal in a first channel, filtering out the modulated carrier component of the color under type video signal to provide the shifted chroma spectrum in a second channel, generating a mixing signal containing time base errors of the reproduced color under type video signal, mixing said mixing signal and said shifted chroma spectrum to heterodyne said shifted chroma spectrum to its original frequency, and adding said demodulated carrier component and said heterodyned chroma spectrum to provide a composite color video signal, whereby the added demodulated carrier component and heterodyned chroma spectrum are substantially in phase.
Claim 2
Independent Claim
131 words
A method of recovering a composite color video signal from a reproduced color under type video signal comprising filtering out the shifted chroma spectrum and demodulating the modulated carrier component of the color under type video signal in a first channel, filtering out the modulated carrier component of the color under type video signal to provide the shifted chroma spectrum in a second channel, generating a mixing signal containing time base errors of the reproduced color under type video signal, mixing said mixing signal and said shifted chroma spectrum to heterodyne said shifted chroma spectrum to its original frequency, and adding said demodulated carrier component and said heterodyned chroma spectrum to provide a composite color video signal, whereby the added demodulated carrier component and heterodyned chroma spectrum are substantially in phase.
Claim 3
Dependent Claim
45 words
The method of claim 1 wherein said mixing signal contains only the long term time base errors of the reproduced color under type video signal, whereby the added demodulated carrier component and heterodyned chroma spectrum are substantially in phase for long term time base errors.
Claim 4
Dependent Claim
141 words
Apparatus for recovering a composite color video signal from a reproduced color under type video signal comprising means in a first channel for filtering out the shifted chroma spectrum and for demodulating the modulated carrier component of the color under type video signal, means in a second channel for filtering out the modulated carrier component of the color under type video signal to provide the shifted chroma spectrum, means for generating a mixing signal containing time base errors of the reproduced color under type video signal, means for mixing said mixing signal and said shifted chroma spectrum to heterodyne said shifted chroma spectrum to its original frequency, and means for adding said demodulated carrier component and said heterodyned chroma spectrum to provide a composite color video signal, whereby the added demodulated carrier component and heterodyned chroma spectrum are substantially in phase.
Claim 5
Dependent Claim
141 words
Apparatus for recovering a composite color video signal from a reproduced color under type video signal comprising means in a first channel for filtering out the shifted chroma spectrum and for demodulating the modulated carrier component of the color under type video signal, means in a second channel for filtering out the modulated carrier component of the color under type video signal to provide the shifted chroma spectrum, means for generating a mixing signal containing time base errors of the reproduced color under type video signal, means for mixing said mixing signal and said shifted chroma spectrum to heterodyne said shifted chroma spectrum to its original frequency, and means for adding said demodulated carrier component and said heterodyned chroma spectrum to provide a composite color video signal, whereby the added demodulated carrier component and heterodyned chroma spectrum are substantially in phase.
Claim 6
Dependent Claim
45 words
The combination of claim 3 wherein said mixing signal contains only the long term time base errors of the reproduced color under type video signal, whereby the added demodulated carrier component and heterodyned chroma spectrum are substantially in phase for long term time base errors.
Claim 7
Dependent Claim
55 words
The combination of claim 4 further comprising means receiving said demodulated carrier component for generating a horizontal sync signal, time base corrector means adapted to receive horizontal sync and color burst reference signals and receiving said horizontal sync signal and composite color video signal for stabilizing time base errors in said composite color video signal.
Claim 8
Dependent Claim
45 words
The combination of claim 5 wherein said horizontal sync signal has only the long term time base errors of the color under type video signal, whereby said time base corrector means stabilizes only the long term time base errors in said composite color video signal.
Claim 9
Dependent Claim
38 words
The combination of claim 6 wherein said means for generating a mixing signal comprises phase locked loop means having a bandwidth capable of following only long term time base errors in the reproduced color under type video signal.
Claim 10
Dependent Claim
49 words
The combination of claim 7 wherein said means for generating a mixing signal further comprises sync stripper means receiving the demodulated carrier component of the color under type video signal for applying the horizontal sync signal of said color under type video signal to said phase locked loop means.
Claim 11
Dependent Claim
137 words
The combination of claim 8 wherein said phase locked loop means comprises phase comparator means for providing a DC error voltage in response to the phase difference between said horizontal sync signal and a feedback signal, voltage controlled oscillator means for providing an output signal at a frequency multiple of said horizontal sync signal having a frequency responsive to said DC error voltage, wherein said output signal is taken as said mixing signal, and frequency divider means receiving said output signal for dividing down said output signal frequency to the horizontal sync signal frequency and for applying said divided down output signal to said phase comparator means as said feedback signal, wherein said feedback signal is taken as said horizontal sync signal having only the long term time base errors of the color under type video signal.
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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |