| 摘要 |
PROBLEM TO BE SOLVED: To obtain a luminance signal and a chrominance signal separator in which occurrence of cross color is suppressed only with a change in a simple circuit configuration. SOLUTION: A signal delayed from an input sampling video signal by (1 line -1 clock) and (1 line + 1 clock) respectively are subtracted by an addition and subtraction circuits 12, 13 and a smaller value of absolute values of output difference signal D1, D2 is extracted from a minimum value circuit 16 and given to a comparator circuit 18, where the signal is compared with a small constantα. If a luminance of a picture element of the signal is equal to the luminance of a picture element in an oblique upper direction to the pixel of the signal like a black-and-white slanted line pattern, an output of the minimum value circuit 16 is smaller than the constantα, '0' is selected as a coefficient of a 1/2.0 coefficient circuit 11 with an output from the comparator circuit 18 to suppress the chrominance signal and to block an output of a mis-chrominance signal due to cross color. In the case of a usual color video signal, the absolute values of the output difference signal D1, D2 are bigger than the constantα, '1/2' is selected as a coefficient of the 1/2.0 coefficient circuit 11 and the luminance signal and the chrominance signal are separated and outputted as usual.
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