| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem due to stray light, which occurs in an optical pickup device for performing reading operation of a signal recorded in an optical disk with a plurality of signal recording layers provided. <P>SOLUTION: An optical pickup device includes an objective lens 9 for focusing laser beams on a signal recording layer, a diffraction grating 2 to be made incident on by laser beams and for generating a main beam being 0-order light and a sub-beam being +1-order light and -1-order light, and a photodetector 11 comprising first and second light receiving parts for sub-beams to be irradiated with a sub-beam reflected from the signal recording layer to generate a tracking error signal and composed of four divided sensors and a light receiving part for a main beam to be irradiated with a main beam reflected from the signal recording layer to generate a reproduction signal and a focus error signal and composed of four divided sensors. The first and second light receiving parts for sub-beams and the light receiving part for a main beam are octagonal in shape. <P>COPYRIGHT: (C)2013,JPO&INPIT |
