| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup capable of performing accurate tracking control even when an unnecessary light is received in the light receiving area of a photodetector. <P>SOLUTION: A main beam applied to an optical disk D, and reflected beams of succeeding and preceding subbeams reflected in a direction around the main beam diagonal to the track direction of the optical disk are received by a PDI having a plurality of light receiving areas A<SB>1</SB>to L<SB>2</SB>by generating ±primary diffracted lights by a hologram element 3 to be subjected to photoelectric conversion, and then an arithmetic operation is carried out to obtain a push-pull signal. The plurality of light receiving areas A<SB>1</SB>to L<SB>2</SB>include light receiving areas A<SB>2</SB>, B<SB>2</SB>, C<SB>2</SB>, D<SB>2</SB>, I<SB>2</SB>, J<SB>2</SB>, K<SB>2</SB>and L<SB>2</SB>for detecting ±primary diffracted lights, and adjacent light receiving areas A<SB>1</SB>, B<SB>1</SB>, C<SB>1</SB>, D<SB>1</SB>, I<SB>1</SB>, J<SB>1</SB>, K<SB>1</SB>and L<SB>1</SB>adjacent thereto to detect unnecessary lights other than ±primary diffracted lights. <P>COPYRIGHT: (C)2007,JPO&INPIT |
