| 摘要 |
<p>Search time increases if spherical aberration has to be varied for each radial location due to the influence of a disk or lens tilt. An optical disk device includes a spherical aberration search unit (spherical aberration setter 52) for varying an amount of spherical aberration applied to a light beam, a focus search unit (focus movement calculator 47 and focus search drive generator 49) for movi ng the focal point of the light beam from a current information plane to a target information plane, a track search unit (track movement calculator 48 and track search drive generator 50) for moving the focal point of the light beam from a current track to a target track, and a search procedure indication unit (search procedure indicator 41) for actuating the spherical aberration search unit, the focus search unit, and the track search unit, in that order, at the time of a search. The search time is reduce d by changing the spherical aberration all at once, both for movement in the layer direction and for movement in the radial direction.</p> |
