| 摘要 |
<p>PURPOSE:To reduce the control pull-in time to ensure the stable tracking control and to improve both functions and performance of a magnetic video recording/ reproducing device, by distinguishing stably and accurately a desired track when the tracking control starts. CONSTITUTION:A control signal Y is inverted to ''L'' from ''H'' at a circuit 42 and synchronously with the fall of a pulse I supplied from a circuit 41. The pulse I is gated with the signal Y to deliver a pulse T. When a track is discriminated by the pulse T, the local pilot signal P1 is immediately produced successively and circularly from the pilot signal equal to that recorded on the track that is scanned at that time point. Thus it is possible to obtain an instantaneous coincidence between the time series of the pilot signal which is reproduced after the track is distinguished and the time series of the local pilot signal. This ensures quick control for subsequent tracks, therefore the pull-in time is reduced.</p> |
