| 摘要 |
PURPOSE:To protect horizontal synchronizing signals from skew and noise, by providing two types or more of time gate circuits different from time gate time, for a PCM tape recorder and the like. CONSTITUTION:The 1st time gate circuit is formed with a gate 9 and a time counter 11, and it is set to a time gate time having high noise proof characteristics, e.g. 61.5musec. The 2nd time gate circuit is formed with the gate 9 and a time counter 12, and it is set to a time gate time in which sufficient fetch can be made even with skew, e.g. 41.5musec. If no skew is present, noise is rejected at the 1st time gate circuit for the detected synchronizing signal. if any skew is present, since the horizontal synchronizing signal is gated, the compensation in done with the output horizontal synchronizing signal is gated, the compensation is done with the output of a 1H delay 10. At the same time, the next horizontal synchronizing signal is fetched through switching to the 2nd time gate circuit. Thus, the horizontal synchronizing signal can be protected from skew and noise. |
