公开(公告)号：JP2000102285A

公开(公告)日：2000-04-07

申请号：JP26739999

申请日：1999-09-21

Applicant: ST MICROELECTRONICS INC

Inventor： SCHLAGER KARL MICHAEL

IPC: G11B21/02 ,  G11B21/08 ,  G11B21/12 ,  H02K33/18 ,  H02P25/02 ,  H02P25/06 ,  H02P7/00

Abstract: PROBLEM TO BE SOLVED: To monitor and correct the speed of a voice coil motor by an arrangement, wherein a feedback circuit delivers a feedback signal from the motion of a head to a voice coil motor control circuit during unloading period from a lamp from a containing position to the vicinity of a disc. SOLUTION: During the unloading period from a lamp from a containing position to the vicinity of a disc, a feedback circuit 18 adds a feedback signal at an input terminal 20 to an analog control signal VIN and compares a resulting voltage with a reference voltage VREF through an amplifier 55, having a gain which is set by the ratio of resistances 57, 59. A controller generates a large drive signal for increasing the speed of a voice coil motor in response to the output signal from the feedback circuit 18 if the comparison results represent a significantly too slow a moving speed of head, otherwise generates a small drive signal.