| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup which can reduce man-hour for initial adjustment in the manufacturing step thereof to be reduced and does not increase the number of components included in the optical pickup. <P>SOLUTION: A dichroic prism is disclosed which includes at least a first reflection film, a second reflection film and a transparent member. The transparent member causes a light beam passing through the inner part thereof to generate astigmatism having a prescribed direction and a prescribed magnitude. Thereby, the astigmatism in a direction reverse to the direction of astigmatism generated by the other optical members e.g. a rising mirror and an objective lens which constitute the optical pickup is caused to generate to cancel them. Thus, astigmatism generated in the whole optical pickup can be reduced by adjusting the material of the transparent member. <P>COPYRIGHT: (C)2009,JPO&INPIT |
