CHROMINANCE/LUMINANCE DIGITAL TO ANALOG SIGNAL CONVERSION

    公开(公告)号:AU1262088A

    公开(公告)日:1988-06-02

    申请号:AU1262088

    申请日:1988-03-01

    Applicant: RCA CORP

    Abstract: In a color television receiver with a digital signal processing system, a chroma processor operates on digital samples containing color picture information to develop first and second binary coded digital signals containing two color mixture signal information such as I color mixture information and Q color mixture information. A luminance processor operates on the digital samples to develop a third digital signal containing Y or luminance information. R, G and B digital signals are related to the developed I, Q and Y digital signals by a set of coefficient multipliers. To obtain the R, G and B digital signals, the I, Q and Y digital signals are applied to a digital decoder that includes a ROM look-up table multiplier for multiplying each of the I, Q and Y signals by the appropriate coefficient multiplier. The products thus generated are summed in an adder to obtain each of the R, G and B signals. A digital-to-analog converter develops analog R, G and B voltages for driving the cathode electrodes of the television receiver color picture tube.

    22.
    发明专利
    未知

    公开(公告)号:FR2599574A1

    公开(公告)日:1987-12-04

    申请号:FR8707518

    申请日:1987-05-27

    Applicant: RCA CORP

    Abstract: In a television receiver including an automatic deghosting system 24, Fig. 1 (634, Fig. 6) means 18, 22 are provided for synchronously demodulating IF television signals to generate baseband signals representing the in phase (I) and quadrature phase (Q) modulation components of the IF signals. A carrier signal extractor circuit 14 extracts the received carrier signal from the radio frequency television signal. A phase locked loop 16 coupled to the carrier signal extracting circuit generates a phase difference signal representing the difference in phase between the oscillatory and the extracted carrier signals. A demodulation phase error detector 26, (630) coupled to the synchronous demodulation means generates a phase control signal proportional to the difference in phase between the direct carrier signal as broadcast and the received carrier signal which may include ghosts. A phase correction circuit 312, 316, 318, Fig. 3 or a ROM (632, Fig. 6) responds to the phase control signal and modifies the phase difference signal (or the first baseband signal) to generate a modified first baseband signal with substantially reduced crosstalk distortion components.

    25.
    发明专利
    未知

    公开(公告)号:FR2536940A1

    公开(公告)日:1984-06-01

    申请号:FR8318862

    申请日:1983-11-25

    Applicant: RCA CORP

    Abstract: In a color television receiver with a digital signal processing system, a chroma processor operates on digital samples containing color picture information to develop first and second binary coded digital signals containing two color mixture signal information such as I color mixture information and Q color mixture information. A luminance processor operates on the digital samples to develop a third digital signal containing Y or luminance information. R, G and B digital signals are related to the developed I, Q and Y digital signals by a set of coefficient multipliers. To obtain the R, G and B digital signals, the I, Q and Y digital signals are applied to a digital decoder that includes a ROM look-up table multiplier for multiplying each of the I, Q and Y signals by the appropriate coefficient multiplier. The products thus generated are summed in an adder to obtain each of the R, G and B signals. A digital-to-analog converter develops analog R, G and B voltages for driving the cathode electrodes of the television receiver color picture tube.

    27.
    发明专利
    未知

    公开(公告)号:FR2512305A1

    公开(公告)日:1983-03-04

    申请号:FR8214804

    申请日:1982-08-30

    Applicant: RCA CORP

    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.

    28.
    发明专利
    未知

    公开(公告)号:IT8223050D0

    公开(公告)日:1982-08-30

    申请号:IT2305082

    申请日:1982-08-30

    Applicant: RCA CORP

    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.

    29.
    发明专利
    未知

    公开(公告)号:FR2551605B1

    公开(公告)日:1988-11-10

    申请号:FR8413464

    申请日:1984-08-30

    Applicant: RCA CORP

    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.

    30.
    发明专利
    未知

    公开(公告)号:FR2512304B1

    公开(公告)日:1988-02-12

    申请号:FR8214803

    申请日:1982-08-30

    Applicant: RCA CORP

    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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