| 摘要 |
<p>PURPOSE:To simplify a circuit constitution by supplying the output of a clock generating means to a clock synchronizing processing circuit, supplying the output of a frequency dividing means to at least a color killer detecting circuit and supplying the output of a phase shifting means to a color demodulation circuit. CONSTITUTION:The titled circuit is provided with the clock generating means for generating the clock of the frequency (n) times as long as a color burst signal 101, the frequency dividing circuit 106 for frequency dividing the clock into (n), a phase detecting circuit 102 for detecting the phase of the color burst signal 101 and the output of the frequency dividing circuit, a low pass filter means for taking out the low frequency component of the output of the phase detecting circuit, a control means for controlling the oscillating frequency of the clock generating means according to the output of the low pass filter means and the phase shifting circuit 109 for shifting the phase of the output of the frequency dividing circuit. The output of the clock generating means is supplied to the clock synchronizing processing circuit 110 operated synchronously with the clock, the output of the frequency dividing circuit is supplied to a chrominance signal processing circuit and the output of the phase shifting means is supplied to the color demodulation circuit. Thereby, the clock generating circuit small in a circuit scale and good in following to the fluctuation of an input signal.</p> |
