| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical head device in which stable tracking servo operation can be achieved while suppressing complexity of constitution and rise of a device price and obtaining a reproduction signal with high quality. <P>SOLUTION: The optical head device has a semiconductor laser 1 emitting a light beam L<SB>1</SB>, an objective lens 7 converging the light beam on an information recording layer of an optical disk 8, a photodetector 12 having a plurality of divided light receiving planes receiving return light beam L<SB>2</SB>reflected by the optical disk 8, and a polarization rotary element 9 arranged in an optical path from the optical disk 8 to the photodetector 12 and giving change to polarization relation of a part L<SB>R2</SB>of the return light beam reflected by the optical disk 8 and a part L<SB>R1</SB>other than the part. <P>COPYRIGHT: (C)2009,JPO&INPIT |
