US4435725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color signal processing circuit to reduce cross-color disturbance and color fringing
Assignee: Toshiba Corp
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Filing: 1981-10-13
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Granted: 1984-03-06
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Expires: 2001-10-13
Abstract
Abstract A composite color video signal including a luminance signal and a carrier chrominance signal multiplexed with the luminance signal is separated by a signal separating circuit to the luminance signal and the carrier chrominance signal. The luminance signal is clipped by a clipping circuit at levels approximating to its black and white peak levels and an output signal of the clipping circuit is shaped to control pulses corresponding to level transitions of the output signal by a wave shaping circuit. A signal attenuating circuit for attenuating the carrier chrominance signals or demodulated color signals in response to color pulses applied thereto is connected in a signal transmission path for receiving the carrier chrominance signal from the signal separating circuit to thereby reduce cross-color and color-fringing components caused at level transitions of the luminance signal.
Inventors
- 👤 Nobuya Nagao
- 👤 Teturou Sakai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:10
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/77; H04N9/64; H04N9/66
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
150 words
A color signal processing circuit comprising: a signal separating circuit means for separating a composite video signal including a luminance signal and a carrier chrominance signal multiplexed with the luminance signal to the carrier chrominance signal and the luminance signal; a clipping circuit means coupled to receive the luminance signal from said signal separating circuit means for clipping the luminance signal at levels near its black and white peak levels to produce a signal containing level transitions indicative of large luminance signal transitions; a control pulse generating circuit means coupled to said clipping circuit means for generating control pulses corresponding to said level transitions; a signal transmission path coupled to receive the carrier chrominance signal from said signal separating circuit means, and including a signal attentuating circuit means for attenuating the carrier chrominance signal applied thereto in response to application of control pulses from said control pulse generating circuit means.
Claim 2
Dependent Claim
150 words
A color signal processing circuit comprising: a signal separating circuit means for separating a composite video signal including a luminance signal and a carrier chrominance signal multiplexed with the luminance signal to the carrier chrominance signal and the luminance signal; a clipping circuit means coupled to receive the luminance signal from said signal separating circuit means for clipping the luminance signal at levels near its black and white peak levels to produce a signal containing level transitions indicative of large luminance signal transitions; a control pulse generating circuit means coupled to said clipping circuit means for generating control pulses corresponding to said level transitions; a signal transmission path coupled to receive the carrier chrominance signal from said signal separating circuit means, and including a signal attentuating circuit means for attenuating the carrier chrominance signal applied thereto in response to application of control pulses from said control pulse generating circuit means.
Claim 3
Dependent Claim
32 words
A color signal processing circuit according to claim 1 wherein said signal attenuating circuit means is coupled to receive output signals of a color demodulation circuit which demodulates the carrier chrominance signal.
Claim 4
Dependent Claim
39 words
A color signal processing circuit according to claim 1 further including a circuit means coupled to the output of said signal attenuating circuit means for eliminating changes in direct-current level of output signal of said signal attenuating circuit means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-06 | 1987-09-05 | 1988-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-06 | 1991-09-05 | 1992-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-06 | 1995-09-05 | 1996-03-06 | $7700.00 | Window Closed / Lapsed |