| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the degree of double refraction of an optical disk formed by injection molding and to provide an optical disk device capable of obtaining a reproducing signal having a high C/N ratio from the optical disk containing double refraction. <P>SOLUTION: In the optical disk 1, the level of the double refraction is set within 60 nm, 60 nm and 40 nm for a read only disk, a WORM type disk and a rewriting type disk, respectively, in the state where two substrates 1a and 1b are stuck to each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
