| 摘要 |
PROBLEM TO BE SOLVED: To shorten a time taken until focus control is performed.SOLUTION: Focus control is performed by: detecting an initial in-focus position PF1 by bringing an objective lens from a first separated position PS1 farther than an in-focus position closer to an optical disk in a state where a rotation of the optical disk is stopped; and following the in-focus position PF1 of a data recording layer by bringing the objective lens closer to the optical disk in a state where the optical disk is rotated after returning to a second separated position PS2 nearer than the first separated position PS1. The initial in-focus position PF1 may be the in-focus position of the data recording layer, and the second separated position PS2 may be a distant position by a prescribed distance E from the initial in-focus position PF1 with respect to the optical disk. |
