| 摘要 |
PURPOSE:To make the black level of a reproduced picture stable, by setting a level of the video signal at the blanking period to a prescribed level and performing the DC component regeneration after eliminating effect of black level deviation of a video signal and processing the waveform so as to reduce the black level to a peak of the black side. CONSTITUTION:A positive video signal is inputted to a video signal input terminal 1, and a switch signal is applied to a switch signal input terminal 20. A transistor (TR) 2 is conductive at the scanning period and outputs the video signal at a video signal output terminal 19. On the other hand, TRs 3 and 4 are conductive only during the blanking period. The inputted video signal is outputted to the video signal output terminal 19 in the waveform replacing the level at the blanking period into a collector voltage of a TR6, i.e., an output Q at the correction level generating section. Peak values at the black side in the video output signals can be arranged to a prescribed value by supplying this video output signal to the DC regenerating circuit. |
