CIRCUIT FOR DETECTING CLEAR RED COLOR AND CIRCUIT FOR COLOR COMPENSATION EMPLOYING THE CIRCUIT FOR DETECTING THE CLEAR RED COLOR

摘要

The present invention relates to a color compensation circuit comprising a red color detection circuit (1) for detecting a red color signal having higher purity, whereby the detection is carried out by inputting color differential signals R-Y and B-Y modulated by a color subcarrier, subtracting the absolute value of the B-Y signal from the positive polarity component of the R-Y signal and removing the negative polarity part of the subtracted signal; Y luminance signal compensation block including: first gain controller (50b) for controlling the output signal amplitude of the red color detection circuit (1) and a subtracter (50a) for subtracting the output signal of first gain controller (50b) from a luminance signal Y; an R-Y signal compensation block including: a second gain controller (51b) for controlling the output signal amplitude of red color detection circuit (1) and an adder (51a) for adding the output signal of second gain controller (51b) and the input R-Y signal; and a B-Y signal compensation block including: a third gain controller (52b) for controlling the output signal amplitude of the red color detection circuit (1), a polarity inverter (52c) for inverting the output signal polarity of the third gain controller (52b), a switch circuit (52d) for selecting either input signal or output signal of the polarity inverter 52c, a polarity discriminator (52e) for discriminating the polarity of the input B-Y signal and an adder (52a) for adding the output signal of switch circuit (52d) and the input B-Y signal.