| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical information recording medium in which good read-out signals can be obtained from both of a reproduction-only region and a recording and reproduction region. SOLUTION: The medium has at least an organic dye film 2 and a reflection film 3 laminated on a card type substrate in which a ROM region and a RAM region are concentrically formed. In the medium, the film thickness d0 of the dye film 2 on the land formed in the ROM and RAM regions is specified to (λ/2)×(1/n1), wherein λ is the wavelength of the laser beam and n1 is the refractive index of the dye film 2. The film thickness dp of the dye film 2 on the pit P formed in the ROM region is controlled to generate almost π rad (inversed phase) phase difference Δθ, while the film thickness d of the dye film 2 on the groove G formed in the RAM region is controlled to generate almost 0 rad (same phase) phase difference Δθ. |
