| 摘要 |
PURPOSE:To improve the SN ratio of a synchronizing signal part at the time of descrambling a video signal scrambled by the compression of a synchronizing signal. CONSTITUTION:A synchronizing signal is separated from a descrambled signal by a synchronizing separator circuit 5. The descrambled signal is applied to a sink chip clamping circuit 2 and a sink chip is clamped on DC voltage applied from a DC voltage generating circuit 3. A switching circuit 4 switches so as to select the DC voltage only in the synchronizing part and select the signal clamped at its sink chip in the other part. Consequently the SN ratio of the synchronizing signal part can be improved. |
