| 摘要 |
PURPOSE:To provide a reproduction circuit for detecting a vertical synchronizing signal oscillating or moving the display picture of a video signal for a non-standard television signal vertically on a display. CONSTITUTION:A V jitter in a V synchronizing signal separated by an NTSC decoder 2 is removed so that the more stable V synchronization is obtained by a V jitter removing circuit 5. In the output of the V jitter removing circuit 5 and a countdown circuit 6 to which a double-speed 2HCLK is supplied, the counted number of horizontal lines of each field is delayed by one frame and is loaded on a line counter. With the line counter, a V synchronizing signal is formed at the same position with the V synchronizing signal of an original signal. Further, the V synchronization is shifted so that the display picture is scrolled freely with a V synchronizing shift circuit 7. |
