| 摘要 |
PURPOSE:To prevent the wow deterioration at a normal operation, to shift smoothly the operation to a tracking scan, to shorten an acting time and to improve the enclosing accuracy and performance by regulating the trucking scan to a short period such as the driving of a motor. CONSTITUTION:A completion detecting circuit 51 is provided to stop an automatic tracking action at the peak of a reproduction video signal 43. Namely, a counter counts the number of inverting times of a signal 62, and when the counted value exceeds a specified value, it is considered to be the completion of the automatic tracking. Receiving a completion detecting signal 60, a start-up and stop circuit 50 operates an ON/OFF switch 51, turns on it and stops the automatic tracking action. Thus the tracking delay quantity is held always at the time of the variable speed reproduction, or before the automatic tracking is started, and therefore the tracking scan in an unnecessary mode or the destruction of data can be prevented, and a smooth action shift can be attained.
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