| 摘要 |
PURPOSE:To obtain a delayed luminance signal with a good SN ratio by obtaining the difference signal Y-Yd/2 between a luminance signal Y and a delayed luminance signal Yd from a C type comb line filter which uses a CCD and subtracting this difference signal from the luminance signal through a nonlinear circuit. CONSTITUTION:The difference signal Y-Yd is led out of an amplifier 49 and supplied to the nonlinear circuit 52 through a trap circuit 51 which removes the band of a chrominance signal C. This nonlinear circuit 52 is so constituted that its output is cut off when the level of the signal Y-Yd is lower than a prescribed level ¦Vth¦ and its input signal Y-Yd is outputted as it is when the level of the signal Y-Yd is higher than the level ¦Vth¦. Then the output signal of this nonlinear circuit 52 is supplied to a subtracting circuit 34 and subtracted from the original brightness signal Y and the subtraction output is led out as a delay output. Consequently, the luminance signal which has the excellent SN ratio and is delayed by one horizontal period is obtained.
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