US3711635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means and method for modifying the flesh-tone response of a color television receiver
Assignee: RCA Licensing Corp
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Filing: 1970-10-26
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Granted: 1973-01-16
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Expires: 1990-10-26
Abstract
Abstract Sensitivity to aberrations in signals carrying flesh-tone color information is reduced by asymmetrically increasing the chroma signal demodulation angle. A phase shifting circuit is placed in series with each of a pair of synchronous demodulators, and means are provided for simultaneously adjusting the circuits to shift the phase of the chroma signals applied to the demodulators. The chroma signals thus applied are phase-shifted to opposite directions, one being shifted approximately three times as much as the other. The relative amplitudes of the chroma signals outputted by the phase shift circuits to the chroma signals outputted by the phase shift circuits to the chroma signals outputted by the phase circuits to the demodulators are also progressively modified, the difference in relative amplitude increasing as the demodulation angle increases.
Inventors
- 👤 R Worden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:32
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/643
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
103 words
In a color television receiver including means for deriving a chroma signal and first and second demodulator means, the method of rendering the flesh tones of an image being displayed by said receiver less sensitive to aberrations in said chroma signal comprising the steps of: inducing a phase lag in said chroma signal to create a lagging phase-shifted signal; applying said lagging phase-shifted signal to said first demodulator means; inducing a phase lead in said chroma signal to create a leading phase-shifted signal; and applying said leading phase-shifted signal to said second demodulator means; said phase lead being larger than said phase lag.
Claim 2
Dependent Claim
103 words
In a color television receiver including means for deriving a chroma signal and first and second demodulator means, the method of rendering the flesh tones of an image being displayed by said receiver less sensitive to aberrations in said chroma signal comprising the steps of: inducing a phase lag in said chroma signal to create a lagging phase-shifted signal; applying said lagging phase-shifted signal to said first demodulator means; inducing a phase lead in said chroma signal to create a leading phase-shifted signal; and applying said leading phase-shifted signal to said second demodulator means; said phase lead being larger than said phase lag.
Claim 3
Dependent Claim
21 words
The method as defined in claim 1, wherein said phase lead is substantially three times as large as said phase lag.
Claim 4
Dependent Claim
51 words
The method as defined in claim 2, further including the steps of: increasing the amplitude of the chroma signals applied to said first demodulator means as said phase lag is increased; and decreasing the amplitude of the chroma signals applied to said second demodulator means as said phase lead is increased.
Claim 5
Dependent Claim
57 words
The method as defined in claim 3 wherein the amplitude of the chroma signal applied to said first demodulator means is increased by substantially 2.5 per cent per degree of phase lag, and the amplitude of the chroma signal applied to said second demodulator means is decreased by substantially 1.7 per cent per degree of phase lead.
Claim 6
Dependent Claim
154 words
In a color television receiver including first and second demodulator means, means for producing a reference signal and means for deriving a chroma signal, said chroma signal having a predetermined phase relationship to said reference signal, means for rendering flesh tone portions of images displayed by said television receiver less sensitive to aberrations in said chroma signal comprising: first phase shifting means to receive said chroma signal and to cause the phase of said chroma signal to lag the received chroma signal by a first angle, said first phase shifting means applying the phase shifted chroma signal to said first demodulator means; second phase shifting means to receive said chroma signal and to cause the phase of said chroma signal to lead the received chroma signal by a second angle, said second phase shifting means applying the phase-shifted chroma signal to said second demodulator means, said second angle being larger than said first angle.
Claim 7
Dependent Claim
154 words
In a color television receiver including first and second demodulator means, means for producing a reference signal and means for deriving a chroma signal, said chroma signal having a predetermined phase relationship to said reference signal, means for rendering flesh tone portions of images displayed by said television receiver less sensitive to aberrations in said chroma signal comprising: first phase shifting means to receive said chroma signal and to cause the phase of said chroma signal to lag the received chroma signal by a first angle, said first phase shifting means applying the phase shifted chroma signal to said first demodulator means; second phase shifting means to receive said chroma signal and to cause the phase of said chroma signal to lead the received chroma signal by a second angle, said second phase shifting means applying the phase-shifted chroma signal to said second demodulator means, said second angle being larger than said first angle.
Claim 8
Dependent Claim
20 words
The invention defined in claim 5, wherein said second angle is substantially three times as large as said first angle.
Claim 9
Dependent Claim
44 words
The invention defined in claim 6, further including: means for simultaneously operating said first and said second phase shifting means to cause first angle and second angle to vary, the relative size of said angles being maintained in the ratio of one to three.
Claim 10
Dependent Claim
55 words
The invention defined in claim 7, further including means for increasing the amplitude of the phase-shifted chroma signal applied to said first demodulator means, and means for decreasing the amplitude of the phase-shifted chroma signal applied by second phase shifting means to said second demodulator means as said first and said second angles are increased.
Claim 11
Dependent Claim
57 words
The invention defined in claim 8, wherein the amplitude of said chroma signal applied to said first demodulator means increases substantially 2.5 per cent for each additional degree of phase lag, and the amplitude of said chroma signal applied to said second demodulator means decreases by substantially 1.7 per cent for each additional degree of phase lead.
Claim 12
Dependent Claim
126 words
The invention defined in claim 9, wherein said first phase-shifting means is operable to cause said chroma signal to be deModulated at an angle which leads said reference signal by substantially 100* , 105*, or 110*, said amplitude increasing means being operable to increase the amplitude of said chroma signal applied to said first demodulator means in the ratio of 1, 1.12, or 1.23 respectively, and said second phase shifting means is simultaneously operable to cause said chroma signal to be demodulated at an angle which lags said reference signal by substantially 10* , 25* or 40*, said amplitude decreasing means being operable to decrease the amplitude of the chroma signal applied to said second demodulator means in the ratios of 1, 0.75 or 0.50 respectively.
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) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |