| 摘要 |
PURPOSE:To contrive to improve the S/N by using a correlation detection signal, an emphasis circuit and a level comparator circuit so as to detect a longitudinal edge, increasing the attenuation of a comb-line filter for a Y signal in this case thereby eliminating a high frequency noise of the edge and decreasing the attenuation of the comb-line filter for the Y signal. CONSTITUTION:A correlation detection pulse is generated from a difference component obtained from an output of a subtractor 2 by a correlation detector 7 and it outputs a correlation detection pulse in the presence of the longitudinal correlation. Moreover, an emphasis circuit 8 emphasizes an input signal and the edge of the leading and trailing of a signal is detected through a waveform shaping circuit 10 so that detection pulse is given at a prescribed white level or over and at a prescribed black level or below by a level comparator circuit 9. Then a longitudinal edge detection pulse is inputted to a switch 12, the attenuation of the comb-line filter for the Y signal is increased for the longitudinal edge part thereby eliminating a high frequency noise, and the attenuation is reduced in the other part to improve the S/N without losing the details of the signal.
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