| 摘要 |
<P>PROBLEM TO BE SOLVED: To stabilize tracking control when there is a relatively large damage or stain caused by fingerprint sticking on an optical disk surface. <P>SOLUTION: The photodetector 5 of the optical integrated unit is provided with light receiving parts 11 to 14 for receiving ± 1st-order diffracted lights, and a light receiving part 15 for receiving a 0-order diffracted transmitted light. Tracking control is executed based on the information of all reflected lights. Thus, the instability of tracking caused by stains or the like on the optical disk surface is prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
