OPTICAL DISK DEVICE AND ITS CONTROL METHOD

PROBLEM TO BE SOLVED: To solve the problem that in the case of the optical disk having a large eccentricity, tracking control is disabled because of impossibility of following the information track of an optical disk unless going beyond the movable area of an objective lens. SOLUTION: The optical disk device is provided with a motor driving part 10 for driving an objective lens 4a in the predetermined movable area of a tracking direction, an analog signal processing part 8 for generating a tracking error signal 102 based on a reflected light from an optical disk, and a controller 12 for driving the motor driving part 10 based on the tracking error signal 102 to perform tracking control. The controller 12 allows the objective lens 4a to be arranged at the end of the predetermined movable area, detects the waveform cycle of the tracking error signal 102, and starts the tracking control when the cycle reaches a predetermined value or more. COPYRIGHT: (C)2008,JPO&INPIT