| 摘要 |
PURPOSE:To stably control a head positioning by driving an actuator based on an external force compensating value and cancelling an external force applied to this actuator. CONSTITUTION:A track cross pulse S2 is up counted or down counted by an up/down counter 23b according to a seek direction to detect the track position of a head, the counted value X is instructed to a ROM 23a as a ROM address according to the track position and the external compensating value V previously written in the ROM address is read. This external compensating value is D/A converted and applied to a driving voltage according to the difference between a speed reference and a current speed is an external compensating voltage S3. This operation is successively carried out until the head is settled to a target track, after the settling, the up/down counter 23b is disabled to prohibit this counting. In such a way, the external force, namely a torque disturbance applied to the actuator 7 can be cancelled by the external force compensating voltage S3 to attain the stable head positioning control.
|
