Patent Number: 6,166,875

Title: Method of positionally controlling a recording/reproducing head so as to follow a rotational frequency component of a disk while eliminating a high order frequency component

Abstract: A disk device includes a magnetic disk carrying servo information and rotatable about a rotational axis, a magnetic head for reading information from the magnetic disk, a positioning unit for positioning the magnetic head radially over the magnetic disk, and a control unit for controlling the positioning unit according to the servo information. The control unit separately measures a rotational frequency component of the magnetic disk and a high-order frequency component which has frequencies higher than the rotational frequency component, and thereafter controls the positioning unit so as to follow the rotational frequency component while eliminating the high-order frequency component. When the magnetic head is positioned along a circular pattern about the rotational axis of the magnetic disk, the magnetic head is prevented from vibrating while compensating for an eccentricity of the magnetic disk.

Inventors: Ueno; Takahisa (Kawasaki, JP), Takaishi; Kazuhiko (Kawasaki, JP)

Assignee: Fujitsu Limited

International Classification: G11B 21/10 (20060101); G11B 5/596 (20060101); G11B 005/596 ()

Expiration Date: 12/26/2017