Pure red color detection circuit and color compensation circuit using the same

A color compensation circuit comprising:

• red color detection means for detecting a red component, using color difference signals (R-Y) and (B-Y);
• and
• Y signal compensation means for compensating a Y signal, using the which receives an output signal of said red color detection means;
• and wherein
• said Y signal compensation means comprises:
• first gain control means for decreasing the an output signal amplitude of said red color detection means;
• and
• second subtraction means for subtracting the an output signal of said first gain control means from the Y signal.

A color compensation circuit comprising:

• red color detection means for detecting a red component, using color difference signals (R-Y) and (B-Y);
• and
• (R-Y) signal compensation means for compensating said (R-Y) signal, using the which receives an output signal of said red color detection means;
• and wherein
• said (R-Y) signal compensation means comprises:
• second gain control means for controlling the an output signal amplitude of said red color detection means;
• and
• first addition means for adding said (R-Y) signal and the an output signal of said second gain control means.

A color compensation circuit comprising:

• pure red color detection means for inputting receiving color demodulated (R-Y) and (B-Y) signal signals and detecting a red color from the (R-Y) and (B-Y) signals;
• gain control means for controlling gain of a red detecting detection signal detected as at said pure red color detection means and outputted from said pure red color detection means;
• and
• addition means inputting for receiving an output signal from said gain control means and the (B-Y) signal, and outputting a compensated (B-Y) signal as a (B-Y)′ signal.

A color compensation circuit comprising:

• pure red color detection means for inputting receiving color demodulated (R-Y) and (B-Y) signals and for detecting a red color from the (R-Y) and (B-Y) signals;
• first and second gain control means for controlling gain of a red detecting detection signal detected at said pure red color detection means and outputted from said pure red color detection means;
• first addition means for inputting the receiving an output signal from said first a third gain control means and the (B-Y) signal, and for outputting a compensated (B-Y) signal as a (B-Y)′ signal;
• and
• second addition means for inputting the receiving an output signal from said second gain control means and the (R-Y) signal, and for outputting a compensated (R-Y) signal as a (R-Y)′ signal.

A color compensation circuit comprising:

• pure red color detecting detection means for detecting a red color component, using color-difference signals (R-Y) and (B-Y);
• first, second and third gain control means for independently controlling gain of a signal detected at said pure red color detection means;
• second first subtraction means for inputting the receiving a signal output from said first gain control means and a Y signal, and for subtracting the signal output from said second first gain control means from said Y signal;
• first addition means inputting the for receiving a signal output from said second gain control means and the (R-Y) signal;
• and
• second addition means inputting the for receiving a signal output from said third gain control means and the (B-Y) signal;
• and wherein
• said pure red color detection means includes:
• slice means for inputting receiving a color demodulated color-difference signal (R-Y) and for extracting outputting an (R-Y) signal component at a slice level;
• absolute value means for inputting a color demodulated color-difference signal (B-Y) and for outputting an absolute value component of said inputted color-difference signal (B-Y);
• first second subtraction means for subtracting the absolute value component of the (B-Y) signal output from said absolute value means, from the (R-Y) signal at said slide level and output from said slice means ;
• and
• limiter means for removing a negative component of the a signal output from said second subtraction means and for outputting a red color component having an (R-Y) signal component in first and second quadrants.

A color compensation circuit comprising:

• red color detection means for detecting a red component, using color differential signals (R-Y) and (B-Y);
• and
• (B-Y) signal compensation means for decreasing an absolute value of said color differential signal (B-Y), using the an output signal of said red color detection means, ;
• wherein said (B-Y) signal compensation means includes:
• third gain control means for decreasing the amplitude of the an output signal of said red color detection means;
• polarity discrimination means for judging an output signal polarity of said color difference signal (B-Y);
• polarity inverting means for inverting the output a signal polarity of an output signal from said third gain control means;
• signal selection means for outputting an output signal of said polarity inverting means if said color differential signal (B-Y) has a positive polarity and outputting an output signal of said third gain control means if said color difference signal (B-Y) has a negative polarity;
• and
• third addition means for adding the an output signal of said signal selection means and said color difference signal (B-Y).

A color compensation circuit comprising:

• red color detection means for detecting a red component, using color differential signals (R-Y) and (B-Y);
• and
• (B-Y) signal compensation means for decreasing an absolute value of said color differential signal (B-Y), using the an output signal of said red color detection means, ;
• wherein said (B-Y) signal compensation means comprises:
• third gain control means for decreasing the an amplitude of the output signal of said red color detection means;
• polarity discrimination means for judging the a polarity of said color difference signal (B-Y) and outputting a +1 if said color difference signal (B-Y) has a negative polarity or a −1 signal if said color difference signal (B-Y) has a positive polarity;
• multiplication means for multiplying the an output signal of said third gain control means by the an output signal of said polarity discrimination means;
• and
• third addition means for adding the an output signal of said multiplication means and said (B-Y) signal.