| 摘要 |
PURPOSE:To reduce an error signal by continuously changing the oscillation frequency of a voltage controlled oscillator in accordance with the speed and the direction of transportation of a magnetic tape in case of quick search even if relative speeds of the tape and a magnetic head are changed. CONSTITUTION:In case that the rotative speed of a capstan 20 is increased in the reproducing and fast-forwarding direction for the purpose of performing quick search, a control circuit 23 reduces the frequency division ratio sent from a programmable frequency divider 22 to a synchronous comparator 17. Then, the rotation number of the capstan 20 is increased through a compensating circuit 30 and a motor driving circuit 18. Simultaneously, the output voltage of a frequency-voltage (F/V) converter 24 is increased, and the control voltage of a voltage controlled oscillator 8 is increased through changeover switches 26 and 27, a compensating circuit 31, and an adder 28. In case of quick rewind ing, the output side of an inverting circuit 25 is selected by the switch 26. Thus, the error signal from a comparator is not greatly changed even if the relative speeds of a magnetic tape 29 and magnetic heads 2a and 2b are increased, and mislocking is prevented.
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