| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk which is compatible with a DVD and can perform higher density recording than the DVD. <P>SOLUTION: In the optical disk 1, wherein at least a first reflection layer 3, a separation layer 4, a second reflection layer 5 and a second substrate 6 having second pits or second guide grooves 6A are sequentially laminated on a first light transmission substrate 2 having first pits or first guide grooves 2A, the pitch of the first pits or the first guide grooves 2A is 0.6 to 0.8 μm, the pitch of second pits or second guide grooves 6A is 0.3 to 0.4 μm, in the first reflection layer 3, reflectance is ≥18% with respect to laser beams of wavelength of 650 nm, the second reflection layer 5 is ≥10 nm in thickness, and the first light transmission substrate 2 and the second substrate 6 are both 0.55 to 0.65 mm in thickness. <P>COPYRIGHT: (C)2007,JPO&INPIT |
