| 摘要 |
<P>PROBLEM TO BE SOLVED: To make laser beams as much as possible incident on a aberration compensating element assembly object in a state of parallel light when first to third laser beams corresponding to three kinds of optical recording media are made incident on the a aberration compensating element assembly object. <P>SOLUTION: To compensate spherical aberration caused by difference of thickness of each substrate of the first to the third optical recording media, the aberration compensating element assembly object 21 is provided between first to third laser light sources 11, 31, 41 and an objective lens 26, first, second, and third laser beams L1, L2, L3 emitted from the first to the third laser beam light sources 11, 31, 41 are made incident on the aberration compensating element assembly object 21 in a state of parallel light. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
