公开(公告)号：JPH06103587A

公开(公告)日：1994-04-15

申请号：JP4457591

申请日：1991-01-17

Applicant: IBM

Inventor： KAGAMI NAOYUKI ,  KUBO HIROAKI ,  NAKASE KOJI

IPC: G11B7/085 ,  G11B7/095

Abstract: PURPOSE: To maintain a still state by operating a controlled variable for moving an optical disk in the radius direction of the optical disk at equal speed on the optical head which is once stopped. CONSTITUTION: A tracking error signal(TES) showing relative displacement quantity against the track of a spot on the optical disk of a laser beam which an object lens 16 emits is transmitted from the optical head 10 to a track counter 26, and a generated number is given to a micro processor 30. The processor 30 has a timer 32 and an analog value by the D/A converter 34 of the digital value of the controlled variable for controlling the head 10 is given to a VCM (voice coil motor) driver 38 through a switch 36. The driver 38 gives driving voltage or driving current based on the analog value to VCM 24. A servo control part 42 controls VCM 24 so that a relative rotary angle against the linear actuator 14 of a rotary actuator 12 becomes zero. Thus, the still state can be maintained.