| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical element which can maintain high transmission efficiency even if a film thickness of a coating layer is increased and an optical pickup device using the same. <P>SOLUTION: The optical pickup device is so constituted that, when the luminous fluxes L parallel to an optical axis are made incident on the optical element OE, the luminous flux L (aligned to a virtual straight line) made incident on an antireflection film RM takes an optical path arriving at the optical element OE by passing the interior of air without returning therein. As a result, the luminous fluxes that can be contributed to beam condensing can be increased and the transmittance can be thereby increased. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
