| 摘要 |
<p>A disc device identifies, based on the amount of eccentricity at each predetermined rotation phase of one revolution of an optical disc (1), the rotation phase range at which the lens shift amount after pulling in of tracking of an objective lens of an optical pickup (3) does not exceed the movement range of a preset tracking direction of the objective lens, sets the rotation shift range as a tracking pull-in range, and executes tracking pull-in of the optical pickup (3) when the rotation shift of the optical disc (1) is within the tracking pull-in range.</p> |
