| 摘要 |
<p>PURPOSE:To enable a suppression of disorder of the synchronization in the servo- system even when in an absence of vertical synchronizing signals in VTR or in a noise mixing, by means of obtaining a reference signal in the method of combination between three monostable multivibrators and an AND gate. CONSTITUTION:A vertically synchronizing signal A to be the reference signal separated from the video signal is applied to a first monostable multivibrator (MV) 36, with its output B used for triggering a second MV19. An output C of the second MV19 is applied to a control head 20 and used as a control recording signal, simultaneously applied to a drive motor control circuit 37 at the time of record reproduction and used as a reference signal. And the output C of the second MV19 is applied to a differentiating circuit 38, with its output F and an output B of the first MV36 used for energizing a gate circuit 39. In this way, the gate circuit is also energized when in an absence of the vertically synchronizing signal, with a mixing of noise inhibited, thus capable of eliminating a disorder of synchronization in the servo- system even at the time of lack of the reference signal and mixing of the noise.</p> |
