| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform tracking control with only an envelope mountaineering control by detecting an envelope level of a regenerative video signal, comparing the levels before/after a phase shift is performed, keeping an applied phase shift direction when the level is increased and reversing the phase shift direction when the level is decreased. SOLUTION: A signal for accelerating or decelerating a capstan motor 1 for a prescribed period and displacing a rotary phase is generated by a speed deviation generator 57 to be added to a rotary control signal by an adder 58. The envelope levels before/after this deviation is added to are compared with each other by an increase/decrease detection circuit 25, and a speed deviation in the same direction is added again when the level is increased, and a speed deviation in the reverse direction is added when the level is decreased. Then, a correction signal is generated by a steady speed deviation correction circuit 72 based on steady speed deviations of a recorder and a reproducing device, and the rotary control signal is added by the adder 58. The speed deviation added by the mountaineering control is reduced sufficiently by correcting the steady speed deviation.</p> |
