| 摘要 |
<P>PROBLEM TO BE SOLVED: To manufacture an optical element made of plastic having very accurate optical characteristics and to provide an optical pickup device having excellent pickup characteristics. <P>SOLUTION: The optical element made of plastic used for the optical pickup device to reproduce and record information from/on an optical information recording medium is molded from cyclic olefin resin containing cyclic olefinic polymer obtained by hydrogenating the copolymer of 2 to 20C α-olefin with cyclic olefin expressed by a prescribed expression, and a specific antioxidant, and has an optical path difference imparting structure to impart a fixed optical path difference to prescribed wavelength light passing through an optical surface on the optical surface. The cyclic olefin resin has light transmittance of ≥85% at 400 nm wavelength, and a melt index of 30 to 60 g/10 min at 260°C temperature and 2.16 kg load in the case of a 3 mm thick molded product. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
