| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively prevent a disk from being damaged caused by lens collision when a near-field beam is used. <P>SOLUTION: A total reflection returned light quantity detected by irradiating a signal recording surface of a rotationally driven optical disk with a laser beam and a near-field beam is differentiated to calculate a movement speed of a lens in an optical pickup. Driving control of the optical pickup or the lens in the optical pickup is performed based on the calculated movement speed. For example, when the calculated movement speed exceeds a predetermined permissible speed, a retreat processing for making the lens apart from the surface of the optical disk is performed. <P>COPYRIGHT: (C)2010,JPO&INPIT |
