| 摘要 |
<p>PURPOSE:To make excellent drive control with simple constitution, by preventing the count down of the output signals of a monostable multivibrator. CONSTITUTION:When the clock signal of a clock oscillator 11 is supplied to a digital type internal synchronizing signal generator 12 composed of a counter, a synchronizing signal Sa is formed and, when the clock signal is supplied to a monostable multivibrator 20, a delay signal Sb is usually formed. The delay signal Sb is supplied to a gate pulse generating circuit 3 and the operation of capstan servo is performed. The count value just before the end of the one frame of the synchronizing signal generator 12 is detected and an edge pulse Sg is generated by an edge pulse generator 13 during the period from the detection to the end of one frame. The edge pulse Sg is supplied to the reset terminal of the multivibrator 20. Therefore, the monostable multivibrator 20 is surely reset just before the end of one frame and no count-down phenomena occur with this monostable multivibrator 20. As a result, excellent drive control can be performed.</p> |
