| 摘要 |
<p>PURPOSE:To make it possible to prevent disturbance of horizontal synchronization in the cue or review reproducing time of a helical scan-type VTR, by using a prescribed rotation control signal. CONSTITUTION:In the cue reproducing time, CTL (control) pulses of a frequency corresponding to the tape running speed are supplied to control voltage supply circuit 22, and DC voltage corresponding to the tape running speed is obtained from the output. This output is supplied to the inversion terminal of operational amplifier 16. Meanwhile, a speed error signal is applied from speed servo circuit 8 to the noninversion terminal of amplifier 16. Consequently, if drum motor 3 is controlled through motor driving circuit 21 by the output of amplifier 16, stable rotation corresponding to the tape running speed can be obtained. In the review reproducing time, CTL pulses are supplied to control voltage supply circuit 23, and motor 3 is controlled similarly. Thus, disturbance of horizontal synchronization in the cue and review reproducing time can be prevented.</p> |
