International Business Machines Corporation

Yoshihiko Aoki

Isao Yoneda

Fuminori Sai

Hiroshi Uchiike

Kenji Ogasawara

Shinji Ueno

The present invention provides a disk drive, a loading/unloading apparatus, and a method for controlling the apparatus, capable of improving the reliability of data by performing stable speed control. A disk drive comprises a VCM spindle driver for rotating a disk, a magnetic head, an actuator mechanism for moving a head slider having the magnetic head to a position above the surface of the magnetic disk and an unloaded position, a ramp block, and a CPU/HDC for performing the speed control of an actuator and the calibration control for detecting the offset and dynamic range of an AD converter before the speed control and controlling the operation for reading or writing data from or into the disk, which increases a rectangular current value to be applied to a voice coil while successively changing codes, measures an offset in accordance with the AD converter value for each current value, and moreover measures a dynamic range by deciding a nonlinear area when the difference between the expected value and measured value of the AD converter becomes a predetermined value or more.

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Ebina, Japan

Yoshihiko Aoki