| 摘要 |
A motor servo circuit is used in a recording and reproducing apparatus which comprises a loop including a comparator for comparing the phases of a signal which is responsive to the rotation of a motor and a reference signal and for controlling the rotation of the motor responsive to an output error signal. The circuit comprises an oscillator for producing a signal having a frequency which is higher than a frequency of the reference signal, a counter for counting the output of the oscillator, which counter resets itself when a full count ff is reached and is reset when a reset signal is applied thereto before the full count ff is reached, a circuit for detecting that the count has reached a first value C1 (C1<ff), and for supplying the reference signal to the comparator, a circuit for detecting that the count has reached a second value C2 (C1<C2<ff) and a third value C3 (C3<C1), and for producing a gate signal during a time period it takes for the count to reach the third value C3 from the second value C2, and a gate circuit responsive to the gate signal, for supplying a vertical synchronizing signal within an input video signal which is to be recorded on a recording medium by the apparatus to the counter as the reset signal.
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