Luminance signal and chrominance signal separating circuit

摘要

In a signal processing circuit for separating a color video signal into a luminance signal and a chrominance signal, whether the correlation relating to the high frequency component of luminance signal and chrominance signal of color video input signal is high or low before and after one horizontal scanning period is detected by a vertical correlation detecting circuit, and the presence or absence of correlation of the detected output signal in the horizontal scanning line is detected by a horizontal correlation detecting circuit. The output signal of the horizontal correlation detecting circuit before and after one horizontal scanning period is supplied into a logic circuit, and depending on the gate output signal obtained therein, the high frequency component of luminance signal and chrominance signal before and after one horizontal scanning period are processed in an operation processing circuit, and a chrominance signal is delivered. Furthermore, this chrominance signal can be obtained through a variable filter circuit capable of changing over the band pass characteristic depending on the output signal of the logic circuit. <IMAGE>