| 摘要 |
PURPOSE:To automatically switch a synchronizing signal used for driving an equipment at the time of reproducing by providing a synchronizing signal separating circuit, a synchronizing signal generating circuit, and a synchronizing switching circuit. CONSTITUTION:At the time of reproducing, the phase of a horizontal synchronizing signal separated by the synchronizing separator circuit 24 and that of a horizontal synchronizing signal outputted from a synchronizing separation generating circuit 18 are compared with each other in a phase comparator circuit 20, and the rotation of a motor 4 is controlled so that said phases agree with each other. To an AND circuit 26, an output signal from a phase adjusting pulse generating circuit 28 which outputs a low-level signal corresponding to the phase difference between a vertical synchronizing signal from the circuit 24 and that from the circuit 18 is inputted. Horizontal synchronizing signals outputted from the synchronizing separator circuit 24 are thinned corresponding to said phase difference between the vertical synchronizing signals from the respective circuits 24, 18, and the rotation of the motor 4 is controlled so that the phases of the respective vertical synchronizing signals are made coincident with each other. As a result, even during the reproduction operation, an optical disk 2 can be rotated in synchronism with video signals inputted to a terminal 6.
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