| 摘要 |
<p>PURPOSE:To reproduce faithfully a signal which is recorded in a video track, by bringing a BPF and a smoothing circuit to AC coupling and inserting them into a variable gain amplifying circuit. CONSTITUTION:A reproducing signal 1a is fetched as a signal 1b related to tracking, for instance, in a shape which has mixed a cross modulation component of 16KHz and 46KHz. This output is made to pass through BPFs 2, 3 and frequencies of 16KHz and 46KHz are fetched, and a 16KHz signal is sent to a smoothing circuit 7 through a capacitor 13 from a variable gain amplifying circuit through a capacitor 12, and a 46KHz signal is sent to a smoothing circuit 8 through a capacitor 14, a fixed gain amplifying circuit 6 and a capacitor 15. Outputs of these circuits 7, 8 are supplied to a differential amplifying circuit 9, and a signal for showing a tracking error is applied to an actuator 11 through a power amplifying circuit 10. In such a way, a reproducing head which is attached to a rotary drum of a video tape recorder is controlled dynamically, and a signal of a video track is reproduced faithfully.</p> |
