COMB FILTER CHROMINANCE AND LUMINANCE SIGNAL SEPARATING CIRCUIT FOR MODIFYING THE LEVEL-FREQUENCY CHARACTERISTIC OF THE LUMINANCE SIGNAL

摘要

A color video signal processing circuit comprising an input terminal through which a color video signal including chrominance and luminance signals is supplied, a signal separating portion which includes both a subtraction-type comb-filter by which a first signal is derived from the color video signal and an addition-type comb-filter by which a second signal is derived from the color video signal, a level modifying portion for emphasizing the level of a first segment of the first signal residing in a predetermined frequency band lower than the frequency band of the chrominance signal and attenuating the level of a second segment of the first signal residing in the frequency band of the chrominance signal, an adder for adding an output of the level modifying portion to the second signal, a first output portion connected to the signal separating portion, and a second output portion connected to the adder. The chrominance signal separated from the color video signal is obtained through the first output portion and the luminance signal separated from the color video signal and modified to have a predetermined level-frequency characteristic is obtained through the second output portion.