| 摘要 |
PURPOSE:To complete a seek action and to stably position on head on a target track by switching the rough control of speed control to the accurate control of position control through a timer started by a prescribed target track front detection signal. CONSTITUTION:When the head is moved to the neighborhood of the target track by the seek action and the target track front detection signal at a least a half track before is outputted, a timer circuit 18 is started by this output. When a prescribed time passes and after that, the output of the circuit 18 becomes H, by an inverter 44, an AND gate 42 and OR gate 46, a change-over switch 30 is turned off, a change-over switch 34 is turned on and the seek action of the rough control through a speed control part 10 is switched to the track action of the accurate control through a position control part 12. Consequently, even when a disturbance such as oscillation occurs just before the target track, the seek action is not kept stopping, completed substantially, the seek action is switched to the track action and the head is stably positioned on the target track. |
