| 摘要 |
This optical disk is two-substrates bonding type. In the optical disk, from the first transparent substrate side toward the second substrate side, at least following layers are laminated in that order; (1) the first transparent substrate, (2) the first optical film, (3) the intermediate layer, (4) the second optical film, and (5) the second substrate. The intermediate layer is formed of a dry photohardenable film of light transmissive type, which has a viscosity of 3,500 to 400,000 poises at a room temperature and in a non-hardened condition and has a thickness of 5 to 200 mu m in the non-hardened condition. The shapes of pits or grooves and the extent of light transmissive property are set so that both of the first pit-groove surface on the first transparent substrate and the second pit-groove surface on the second substrate can be read by irradiating the optical disk with the beam for reproduction from the first transparent substrate side of the optical disk. According to this optical disk, it is possible to improve the recording or reproducing density, transmission rate, and reproducing time while no reading obstruction is caused.
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