| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem caused by stray light occurring in an optical pickup device that performs read-out operation of a signal recorded on an optical disc in which a plurality of signal recording layers are provided. <P>SOLUTION: An optical pickup device includes: a diffraction grating 2 on which a laser beam is incident and that generates a main beam and a sub beam; a photodetector 10 that consists of first and second sub beam receiving units that are irradiated with a sub beam being return light reflected from a signal recording layer and generate a tracking error signal, and a main beam receiving unit that is irradiated with a main beam being return light and generates a reproduction signal and a focus error signal; and a polarization beam splitter that guides the laser beam transmitted through the diffraction grating 2 toward an objective lens 8 and guides the return light reflected from the signal recording layer toward the photodetector 10. An intensity distribution of the return light made incident on the photodetector 10 is made flat. <P>COPYRIGHT: (C)2013,JPO&INPIT |
