公开(公告)号：JPH1125626A

公开(公告)日：1999-01-29

申请号：JP17184997

申请日：1997-06-27

Applicant: IBM

Inventor： YONEDA ISAO ,  UCHIIKE HIROSHI ,  UENO SHINJI ,  OGASAWARA KENJI ,  AOKI YOSHIHIKO ,  SAI FUMINORI

IPC: G11B21/02 ,  G11B5/54 ,  G11B19/04 ,  G11B19/28 ,  G11B21/12 ,  G11B19/12

Abstract: PROBLEM TO BE SOLVED: To provide a disk drive device, a load/unload device and its control method performing stable speed control and improving reliability in data. SOLUTION: The disk drive device 10 is provided with a VCM(voice coil motor) spindle driver 12 rotation driving a disk 11, a magnetic head 13, an actuator mechanism 14 moving a head slider having the magnetic head 13 over the magnetic disk 11 surface and to a retreat position, a lamp block 15 and a CPU/HDC (hard disk controller) 16 controlling a speed of an actuator, controlling calibration detecting offset and dynamic range of an AD(analog/digital) converter prior to this speed control and controlling operation such as read-out/ write-in, etc., of data for the disk 11. Then, the device 10 increases a rectangular current value applied to a voice coil while successively changing a code, and measures the offset from the value of the AD converter at every current value, and decides it is a nonlinear area when a difference between the expected value and the measured value of the AD converter becomes a prescribed value or above to measure the dynamic range.