Patent ID: 8325574
Filing Date: 2012-12-04
Classification: G11B

Abstract:
1. An optical disc device for reproducing or recording information on an optical disc by using laser light, comprising: an objective lens configured to condense the laser light; an actuator configured to drive the objective lens; a detector configured to detect a reflected light from the optical disc; a focus error signal generating unit configured to generate a focus error signal from the reflected light detected by the detector; a tracking error signal generating unit configured to generate a tracking error signal from the reflected light detected by the detector; a control unit configured to generate and output a focus drive signal and a tracking drive signal generated by using the focus error signal and the tracking error signal to control the actuator; and a signal variation amount measuring unit configured to measure amounts of variation in the focus drive signal and the tracking drive signal, wherein the control unit is configured to control in such a manner as to change characteristics of at least one of a focus servo control system and a tracking servo control system to suppress the amounts of variation, when the amounts of variation in at least one of the focus drive signal and in the tracking drive signal is equal to or greater than a predetermined amount when the optical disc has been rotated a desired number of rotations.