Burst phase correcting circuit
AssigneeSanyo Electric Co., Ltd.
InventorsNobukazu Hosoya, Yoshichika Hirao
Life of this patent
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Abstract
A burst phase correcting circuit includes a first all-pass filter which receives a chrominance sign inputted from a terminal. A phase reference signal from an oscillator is applied to a first phase-comparator together with an output signal from the first all-pass filter, after the same is phase-shifted by 90 degrees by a first phase-shifter. A signal according to a phase difference of the both signals is outputted from the first phase-comparator and applied to the first all-pass filter via a first low-pass filter and a capacitor. Therefore, in the first all-pass filter, a delay time is varied in accordance with the phase difference between the chrominance signal and the phase reference signal. Therefore, a jitter component of the chrominance signal can be removed.
Claims13
A burst phase correcting circuit, comprising:
- first variable delay means which receives a chrominance signal, and delays said chrominance signal with a delay time according to a control signal, and outputs the chrominance signal;
- reference signal generating means for generating a reference signal;
- first phase-shifting means for phase-shifting said reference signal by 90 degrees;
- timing signal applying means for applying a timing signal;
- first phase-comparing means for comparing a phase of an output of said first variable delay means with a phase of an output of said first phase-shifting means in response to said timing signal to output a signal according to a difference between the both phases;
- a first low-pass filter for receiving said signal from said first phase-comparing means;
- and
- a capacitor for applying only an alternating current component included in an output of said first low-pass filter to said first variable delay means as said control signal;
- wherein said timing signal applying means includes burst signal demodulating means for applying a burst gate signal which is obtained by demodulating a burst signal included in the output of said first variable delay means to said first phase-comparing means.
A burst phase correcting circuit, comprising:
- first variable delay means which receives a chrominance signal, and delays said chrominance signal with a delay time according to a control signal, and outputs the chrominance signal;
- reference signal generating means for generating a reference signal;
- first phase-shifting means for phase-shifting said reference signal by 90 degrees;
- timing signal applying means for applying a timing signal;
- first phase-comparing means for comparing a phase of an output of said first variable delay means with a phase of an output of said first phase-shifting means in response to said timing signal to output a signal according to a difference between the both phases;
- a first low-pass filter for receiving said signal from said first phase-comparing means;
- a capacitor for applying only an alternating current component included in an output of said first low-pass filter to said first variable delay means as said control signal;
- and
- second variable delay means for receiving a luminance signal, said second variable delay means being controlled by said control signal from said capacitor;
- wherein said timing signal applying means includes bursts signal demodulating means for applying a burst gate signal which is obtained by demodulating a burst signal included in the output of said first variable delay means to said first phase comparing means.
A television signal processing apparatus, comprising:
- first variable delay means which receives a chrominance signal, and delays said chrominance signal with a delay time according to a control signal, and outputs the chrominance signal;
- reference signal generating means for generating a reference signal;
- first phase-shifting means for phase-shifting said reference signal by 90 degrees;
- timing signal applying means for applying a timing signal;
- first phase-comparing means for comparing a phase of an output of said first variable delay means with a phase of an output of said first phase-shifting means in response to said timing signal to output a signal according to a difference between the both phases;
- a first low-pass filter for receiving said signal from said first phase-comparing means;
- and
- a capacitor for applying only an alternating current component included in an output of said first low-pass filter to said first variable delay means as said control signal;
- wherein said timing signal applying means includes burst signal demodulating means for applying a burst gate signal which is obtained by demodulating a burst signal included in the output of said first variable delay means to said first phase-comparing means.
Dependencies are inferred from the claim text.