| 摘要 |
<P>PROBLEM TO BE SOLVED: To stabilize a tracking signal and a focusing signal by removing multi-layer cross talk, and to prevent deterioration of quality of a data signal. <P>SOLUTION: In reflected light from a multi-layer disk 501, reflected light from the layer 511 is bisected by a luminous flux dividing optical system 107 so as to spread to two parts at a center line and condensed. At this time, reflected light from the other layer is not made incident on the condensing position of the reflected light from the layer 511, and since only the reflected light from the layer 511 can be detected by a detector 52, cross talk from the other layer is not caused. <P>COPYRIGHT: (C)2011,JPO&INPIT |
