US 7,564,641 B2
Controller-characteristic changing apparatus, storage device, controller-characteristic changing method, and computer product
Mitsuo Kamimura, Kawasaki (Japan); Fumiya Kudo, Kawasaki (Japan); Yukio Abe, Kawasaki (Japan); Atsushi Suzuki, Kawasaki (Japan); and Takeshi Hara, Kawasaki (Japan)
Assigned to Fujitsu Limited, Kawasaki (Japan)
Filed on Oct. 31, 2006, as Appl. No. 11/590,725.
Claims priority of application No. 2006-166610 (JP), filed on Jun. 15, 2006.
Prior Publication US 2007/0291399 A1, Dec. 20, 2007
Int. Cl. G11B 21/02 (2006.01); G11B 5/596 (2006.01)
U.S. Cl. 360—75  [360/77.02] 16 Claims
OG exemplary drawing
 
1. A controller-characteristic changing apparatus that changes a controller characteristic of a controller that controls positioning of a head that performs at least one of data writing and data reading with respect to a storage medium, the controller-characteristic changing apparatus comprising:
an vibration detector that detects whether the head is subjected to external vibration due to an external factor;
a first changing unit that, when the vibration detector detects the external vibration while the controller is controlling the positioning of the head according to a positioning-oriented controller characteristic that takes an accuracy of positioning the head into account, changes the positioning-oriented controller characteristic to a vibration-reducing controller characteristic that improves a reduction effect of vibration of a first frequency band; and
a second changing unit that, when the vibration detector detects absence of the external vibration while the controller is controlling the positioning of the head according to the vibration-reducing controller characteristic, changes the vibration-reducing controller characteristic to the positioning-oriented controller characteristic, wherein
a reduction rate of the vibration of the head for the vibration-reducing controller characteristic is higher than a reduction rate of the vibration of the head for the positioning-oriented controller characteristic in the first frequency band, and
the reduction rate of the vibration of the head for vibration-reducing controller characteristic is lower than the reduction rate of the vibration of the head for positioning-oriented controller characteristic in a second frequency band that is higher than the first frequency band.