Head-positioning control method and device for a disk device
AssigneeFujitsu Limited
InventorsKazuhiko Takaishi, Shunji Saito
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Abstract
This invention relates to a head-positioning method and device for positioning the head, that reads a disk medium, to a specified position. A disk device having a head, actuator and control circuit comprises: a demodulation unit for demodulating the demodulated position from the head output, a calculation unit for calculating the error between the demodulated position and target position, and a gain-correction unit for correcting the error with a gain. Since a relative position is used, it is possible to accurately detect the position error, for which the non-linear characteristics of the head sensitivity distribution have been corrected, at each offset position.
Claims12
A head-positioning control method for a disk device for positioning a head at a specified position on a disk and comprising:
- a step of demodulating a position information on said disk that is read by the head;
- a step of calculating a position error between said demodulated position and a target position;
- a step of correcting said position error using a set position gain according to an offset from a center of a track of the target position;
- a step of calculating the amount of control for the actuator that drives said head according to said corrected position error;
- and
- a step of driving said actuator with said control amount,
- wherein said demodulation step comprises a step of correcting the offset signal of the position information by a sensitivity gain that is set for a track number in the position information.
A head-positioning control device for a disk device for driving an actuator and positioning a head at a specified position on a disk comprising:
- a demodulation circuit for demodulating the position information on said disk that is read by the head;
- and
- a control circuit for calculating the amount of control for said actuator according to a position error between said demodulated position and a target position;
- wherein said control circuit corrects said position error by a set position gain according to the offset from the center of the track of the target position, then calculates the amount of control for the actuator, that drives said head, according to said corrected position error,
- wherein said demodulation circuit corrects the offset signal of the position information by a sensitivity gain that is set for a track number in the position information.
A disk device comprising;
- a head for at least reading a disk;
- an actuator for positioning said head at a specified position on said disk:
- a demodulation circuit for demodulating the position information on said disk that is read by the head;
- and
- a control circuit for calculating the amount of control for said actuator according to a position error between said demodulated position and a target position;
- wherein said control circuit corrects said position error by a set position gain according to the offset from the center of the track of the target position, then calculates the amount of control for the actuator, that drives said head, according to said corrected position error,
- wherein said demodulation circuit corrects the offset signal of the position information by a sensitivity gain that is set for a track number in the position information.
Dependencies are inferred from the claim text.