| 摘要 |
<P>PROBLEM TO BE SOLVED: To appropriately detect various signals by reducing adverse effects of the reflected light beams from a far side recording layer, i.e., flare, made on the signals while focusing is made onto a recording layer near the objective lens. <P>SOLUTION: In the optical pickup apparatus, an optical disk having two recording layers is irradiated with a light flux from a semiconductor laser through the objective lens, the reflected light beams from the disk are guided onto a light receiving element through the objective lens, a hologram 20 and a grating and information on the disk is reproduced. As a light receiving region of the hologram 20, two regions C and D which are used to detect the push-pull signals and one region AB which is used to detect focus error signals, total of three regions are formed and an optical axis is set within the region AB. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
