| 摘要 |
PURPOSE:To obtain a processing circuit reducing noise and correcting vertical shift in a chroma signal on a screen, by switching a compensation signal of dropout period around the horizontal synchronizing signal, in a VTR. CONSTITUTION:A signal reproduced at a video head 1 is amplified at a preamplifier 2, a luminance FM signal is obtained through a high pass filter 3 and a chroma signal is obtained through a low pass filter 4. At the period without dropout, a switch 5 is selected to the down-position, a luminance FM signal is inputted to a 1H dela line 6, the delayed output is demodulated into a video signal at a demodulator 7 and led to a mixing circuit 8, mixed with a chroma signal from a comb-type filter 11 and a reproduced video signal is outputted. If dropout takes place, the switch 5 is selected to the inverted position, an input signal is changed over to an output signal of the delay line 6, the input and output of the delay line 6 are the same information signal, and a video signal prior to 1H is demodulated at the output of the demodulator 7, allowing to compensate any long dropout. |
