| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the possibility of damaging of a condensing element or a recording medium caused by collision of the condensing element with the recording medium. <P>SOLUTION: The target value of a gap in a near field is set at a plurality of stages (52 and 53), and the gap is controlled at stages according to the target value. In other words, the gap is controlled to be larger before a change to a final gap where the possibility of an objective lens being brought into contact with dusts on a disk to collide with the disk via the dusts is relatively high. Thus, the possibility of collision of the objective lens with the disk is reduced, and it is safely shifted to the final gap. <P>COPYRIGHT: (C)2007,JPO&INPIT |
