| 摘要 |
<p>PROBLEM TO BE SOLVED: To accumulate speed error signals from tracking control signal and to reduce the disturbance of a phase control signal by negative-return controlling a driver with a phase control signal formed by accumulating error signals between a take-up speed and a target speed and shortening phase pulling-in. SOLUTION: A winding quantity detector 20 calculates a total tape projection area and a reel radius by the output signals of the rotational speed detectors 8 and 9 of supply S and take-up T reel motors. Then, a T reel speed calculator 21 calculates a take-up speed and an adder 17 calculates a speed error by the target speed of a target speed generator 25. Simultaneously, speed error signals are sequentially accumulated by an integrator 26, a phase control signal is produced, speed error signals are added by an adder 18 via a switch circuit 32, a motor driver 14 is negative-return controlled and a phase pulling-in time is shortened. Then, in a recording state, a switch is changed by the integrator 26, speed error signals are sequentially accumulated by tracking control signal values from a PG generation circuit 10 and a synchronizing signal extracting circuit 19 and thus the disturbance of the phase control signal is reduced.</p> |
