| 摘要 |
<p>PURPOSE:To make it possible to obtain stable pictures by reducing noises in high- speed reproduction by feeding a reproduced control signal back to a tape driving motor and by locking the phase so that the tape speed will be equal to a normal speed increased by an even number. CONSTITUTION:A tape run speed in high-speed reproduction is equalized to a normal speed increased by even number 2n and a reproduced control CTL signal that corresponds to it is detected and supplied to input terminal 4. Then, it is amplified and counted down to 1/2n by counting-down counter 6 to generate a trapezoid-wave signal. This trapezoid signal is sampled by phase comparing circuit 3 with switching pulses from input terminal 1 and according to the phase error, the rotational frequency of tape driving motor 9 is controlled to hold the tape run speed in high-speed reproduction 2n times the normal speed.</p> |
