| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device that reduces interlayer crosstalk without changing the configuration of an optical system or excessively increasing the overall size of the optical system. <P>SOLUTION: The optical pickup device reproduces a signal from a multilayer optical information recording medium 6 having a plurality of information recording layers 6a, 6b, and 6c. As a collimating optical system for collimating light from a light source 1, a collimating lens unit 3 is used, which includes first and second lens groups 8 and 9 arranged at predetermined intervals therein to form a converged light spot, and an optical element 10 disposed between the first and second lens groups 8 and 9 and configured to reduce the amount of light transmitted through the collimating lens unit 3 by forming a light spot at a position shifted from the position of the converged light spot. <P>COPYRIGHT: (C)2011,JPO&INPIT |
