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公开(公告)号：FR2523793B1
公开(公告)日：1989-08-18
申请号：FR8304395
申请日：1983-03-17
Applicant: RCA CORP
Inventor： LEWIS HENRY GARTON JR , ELISCU ET STEVEN MICHAEL
Abstract: The gain of the chroma signal in a digital television receiver is controlled in accordance with the value of a composite gain factor which is an accumulation of gain control factors provided by a user color control, automatic chroma control, and chroma overload. Gain control according to the composite gain factor is realized by a coarse gain block, which increments or decrements the chroma signal gain in increments of six dB, and a fine gain control over a range of six dB or less, in finely controlled increments. In a preferred embodiment, the digital chroma gain system is operated under control of a microprocessor, which receives signals representative of chroma overload, user control settings, and chroma burst amplitude. The microprocessor then calculates the composite chroma signal gain and apportions the gain between the coarse and fine gain control blocks. In the preferred embodiment of the invention, the coarse gain block comprises controlled shift registers for controlling the chroma signal gain over a range of 18 dB in 6 dB increments. The fine gain block comprises an adder and a random access memory (RAM), addressed by the chroma signal, which contains a data table computed by the microprocessor.
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公开(公告)号：FR2531294B1
公开(公告)日：1988-11-25
申请号：FR8312493
申请日：1983-07-28
Applicant: RCA CORP
Inventor： LEWIS HENRY GARTON JR
Abstract: In a television receiver with digital signal processing circuitry, a composite video signal is sampled by an analog-to-digital converter. A luminance processor responsive to the digital samples of the composite video signal develops digital luminance signals and a chrominance processor develops digital chrominance signals. A digital-to-analog converter coupled to the luminance and chrominance processors develops a plurality of analog output voltages representative of the luminance and chrominance information. A driver circuit converts the analog output voltages to drive signals that are applied to the cathode electrodes of a color picture tube to produce a display of the picture information contained in the composite video signal. A signal generator develops a control signal that is applied to a reset line of the digital-to-analog converter to establish the analog output voltages at predetermined levels. If the control signal, for example, is indicative of the blanking interval within the composite video signal, the predetermined levels established are ones that will produce a blank display.
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Patent Agency Ranking
公开(公告)号：IT1159089B
公开(公告)日：1987-02-25
申请号：IT2305082
申请日：1982-08-30
Applicant: RCA CORP
Inventor： LEWIS HENRY GARTON JR
Abstract: An arrangement is provided for developing timed clock signals for a digital baseband television signal processing system. An AFPC loop circuit is responsive to the color burst signal component of a received analog video signal for producing a continuous wave signal which is aligned in frequency and phase with the color burst signal. The continuous wave signal is applied to a tint control circuit, which is responsive to a control signal, for variably shifting the phase of the continuous wave signal. The phase-shifted continuous wave signal is then applied to a phase-locked loop circuit, which produces a sampling signal for an analog-to-digital converter at a frequency which is a multiple of the color subcarrier frequency and with a phase which will result in a reproduced image of a desired tint or hue. In one embodiment of the present invention, the continuous wave signal is phase-shifted by a series of logic gates having a plurality of output taps. A multiplexer selects a signal of a desired phase shift from one of the output taps, which signal is then applied to the phase-locked loop circuit for generation of the sampling signal.
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公开(公告)号：AT23414T
公开(公告)日：1986-11-15
申请号：AT83306277
申请日：1983-10-17
Applicant: RCA CORP
Inventor： LEWIS HENRY GARTON JR
Abstract: A digital television processing system is provided which contains error correction capability, A digital processing section (23, 26, 31, 36, 37, 38, 45, 46, 51, 52) accepts first digital samples as input and produces modified digital samples (Yc) as output. These respective digital samples each contain picture information. A processing stage (23, 45, 46) in the digital processing section, however, when supplied with selected input digital samples, produces digital output samples (Yp) subject to error. The modified picture information, derived from the output samples subject to error possibly contains erroneously modified picture information. A digital-to-analog converter (49, 50) accepts the modified (possibly erroneous) digital samples and produces an analog signal (Y min ) containing picture information subject to error. An error detector (70) is coupled to the digital processing stage for detecting the presence of the error. Correction means (48) are coupled to the digital-to-analog converter to change the analog signal upon detection of an error to a different analog signal such that the picture information is corrected for the effects of the error.
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公开(公告)号：ZA846798B
公开(公告)日：1985-04-24
申请号：ZA846798
申请日：1984-08-30
Applicant: RCA CORP
Inventor： LEWIS HENRY GARTON JR
Abstract: A deghosting system incorporated in a digital television signal processing system includes a number of channels for producing digital samples of psuedo ghost signals for cancelling digital samples of respective ghost components of a contaminated video signal. Each channel includes a random access memory into which digital video samples are read and later read out of at a time corresponding to the delay between the respective ghost component and the main (desired) component of the ghost contaminated video signal. The resulting delayed digital samples are multiplied with an appropriate coefficient to generate the digital samples of the psuedo ghost signal.
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公开(公告)号：DE3328018A1
公开(公告)日：1984-02-09
申请号：DE3328018
申请日：1983-08-03
Applicant: RCA CORP
Inventor： LEWIS HENRY GARTON JR
Abstract: A sampled data filter operates on sampled data signal sequences composed of regularly occurring interleaved sample sequences to produce filtered replicas of particular ones of the regularly occurring samples of each sequence. The filter comprises a plurality of shift registers (A, B, C) between which all of the interleaved input samples (ABC DATA) are distributed by a demodulating circuit (DEMUX). Weighting circuits (K1-K8) are coupled by respective means to output taps on the registers for weighting samples at the respective taps. The weighted samples are summed in an adder circuit (+, +....) to produced filtered output samples (Bi').
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公开(公告)号：ZA826358B
公开(公告)日：1983-07-27
申请号：ZA826358
申请日：1982-08-31
Applicant: RCA CORP
Inventor： LEWIS HENRY GARTON JR
Abstract: A digital filter arrangement is provided which both demodulates and filters the color mixture signals in a television receiver. Samples of a digital chrominance signal are clocked into first and second registers such that the first register is loaded with samples of a first color mixture signal and the second register contains samples of a second color mixture signal. Output taps are connected between various ones of the stages of the first and second registers and weighting function circuits. The weighting function circuits associated with each register are in turn coupled to respective ladder networks of adders, which combine the weighted signals samples so as to exhibit, at an output stage adder, a lowpass response characteristic which is appropriate for the respective color mixture signal. The two digital registers are aligned in time in accordance with their respective peak impulse response characteristic to product filtered color mixture signals in a proper timed relationship.
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