公开(公告)号：JP2001250311A

公开(公告)日：2001-09-14

申请号：JP2000063806

申请日：2000-03-08

Applicant: SONY CORP

Inventor： OSADA ATSUSHI ,  SHIOZAWA MASAZUMI

IPC: G11B17/022 ,  G11B19/02 ,  G11B19/20

Abstract: PROBLEM TO BE SOLVED: To provide an optical disk device in which rechucking is automatically conducted so that the amount of eccentricity becomes not larger than a prescribed threshold value by using a simple constitution. SOLUTION: An amount of eccentricity x of a disk 20 mounted on a turntable 7 is computed by a system controller 10. When the amount x approaches a threshold value A, a focus servo is turned OFF, either one of a first mode, in which a spindle motor 6 is stopped and chucking is released, or a second mode, in which the motor 6 is set to run at a low speed and a soft chucking state is set, is set. Then, rechucking is automatically repeated from the first or the second mode until the amount x becomes not larger than the value A. Thus, especially during a writing in a high speed rotation/chucking of a reproducing operation, no frequent retry of error processing is conducted by the generation of an error due to improper follow-up of a tracking servo caused by the eccentricity by employing a simple constitution. Moreover, reduction in the efficiency of reproducing/writing is prevented and highly precise recording/reproducing operations are made possible.