Patent ID: 7593293
Filing Date: 2009-09-22
Classification: G11B

Abstract:
1. An optical disk drive comprising: a main body; a pickup head for radiating a laser beam to a beam position on an optical disk set on the main body, the disk having a plurality of tracks; a controller for performing tracking servo control and causing the beam position to follow the tracks; a disk discriminating means for determining whether the optical disk has areas of a first area and a second area for which the tracking servo control is to be performed by a first method and a second method respectively, some of the tracks being formed in the first area, the other tracks being formed in the second area; a seeking means for causing the pickup head to perform seek operations; an estimating means for estimating the beam position where a laser beam is radiated from the pickup head stopping after the head is moved to make a first seek by the seeking means; and the seeking means being adapted to cause the pickup head to make a second seek by a specified number of addresses toward an opposite direction from the first seek, on the area including a target of the first seek, under all the conditions of the following (a)-(d), after the first seek is made; wherein the controller is adapted to perform the tracking servo control after the second seek made, and wherein, the conditions are as follows: (a) the controller cannot perform the tracking servo control at the beam position after the first seek is made; (b) the discriminating means determines that the optical disk has the first and second areas; (c) the first seek is made toward the direction of moving near a boundary between the areas, and (d) the beam position estimated after the first seek is made is inside a specified critical region including a boundary between the areas.