| 摘要 |
<p>A Y/C separation circuit includes a glass delay line for delaying an input composite video signal. A luminance signal and a chrominance signal are separated from each other by an adding circuit and a subtracting circuit each of which receives the input signal and an output signal from the glass delay line. The output signal from the glass delay line is phase-shifted by a 90 DEG phase shifting circuit and then inputted to a multiplier which further receives the input signal. The multiplier outputs an error signal according to a phase difference between color burst signals included in the both signals, and a control voltage according to the error signal is outputted from a low-pass filter. The control voltage is applied to gyrators which terminate an input and an output of the glass delay line, respectively, whereby an inductance value of each of the gyrators is controlled by the control voltage such that a delay time of the glass delay line can be exactly adjusted at one horizontal period. <IMAGE></p> |
