| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a compatible optical pickup device capable of smoothly restricting influence by stray light and simplifying constitution of a photodetector, while using an existing three-beam system technique. <P>SOLUTION: A BD sensor group B1 to B8 is disposed in a signal light area formed on a photodetector 120 by a spectral element 118. CD sensor groups C01 to C04, C11 to C14, and C21 to C24 are disposed in positions irradiated with zero-th order diffraction light of a main beam and two sub beams of CD light that has been transmitted through the spectral element 118 without being diffracted. The CD sensor group includes a four-divided sensors C01 to C04 which receive the main beam of the CD light. The four-divided sensors C01 to C04 are disposed in an area surrounded by the BD sensor group. Zero-th order diffraction light of the BD light that has been transmitted through the spectral element 118 without being diffracted is radiated onto the four-divided sensors C01 to C04 in a state of being matched with an optical axis of the CD light main beam. <P>COPYRIGHT: (C)2012,JPO&INPIT |
