| 摘要 |
PROBLEM TO BE SOLVED: To provide a superimpose pulse automatic setting circuit for an external synchronizing system in which synchronism can be easily established without necessity of manual switching setting corresponding to an apparatus such as a camera. SOLUTION: If a video signal is inputted or a power source is turned on, a superimpose pulse which becomes a reference of external synchronism is superimposed on the video signal for a fixed period of time for each signal channel for which a video signal input can be confirmed, and a synchronous state is automatically judged from the relationship of synchronizing signal phases of the superimpose pulse and the video signal. Furthermore, the state of confirming the video signal input is maintained and as long as the synchronous state is judged, timing pulses are continuously superimposed. COPYRIGHT: (C)2006,JPO&NCIPI
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