公开(公告)号：JP2000339821A

公开(公告)日：2000-12-08

申请号：JP2000122996

申请日：2000-04-24

Applicant: IBM

Inventor： JEFFREY JOSEPH DOBEC ,  ROWAN BRYAN SCOTT ,  LEWIS JOSEPH SERRANO ,  MANTORU MAN HON YUU

IPC: G11B19/20 ,  G11B19/28 ,  G11B21/02 ,  G11B21/21 ,  H02P29/00 ,  G11B19/02 ,  H02P5/00

Abstract: PROBLEM TO BE SOLVED: To reduce latent possibility of delay in a servo control loop at the time of achieving an appropriate spindle speed by compensating previously drag effect in head loading from a lamp position of a disk drive. SOLUTION: A feed forward control device 30 including a control loop is provided in a form of firmware, drag variation during head loading operation is decided, appropriate control is applied to a spindle motor 16 using expected drag variation, and drag variation is previously compensated. That is, expected drag variation follows the prescribed variation generated by the prescribed servo mechanism system. The control device 30 compensates previously expected drag variation, and provides a feed forward control signal generating a control output signal converted by a D/A 12 to a motor pre-driver 14 by combining with an output signal of a control device of a digital control device 32. Therefore, control in which the speed of the spindle motor 16 is limited in a specified tolerable range is performed during head load process.