| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multi-layered phase-change optical recording medium, wherein each of information layers other than an information layer disposed at the innermost side has a high light transmittance to allow recording and reproduction of information in the respective information layers under stable tracking accuracy and which is superior in storage stability. <P>SOLUTION: The multi-layered phase-change optical recording medium has a plurality of information layers, layered in between first and second substrates having groove guides via an intermediate layer; each information layer other than an information layer disposed at the innermost side, as viewed from the first substrate side, comprises a lower protective layer, a phase-change recording layer, an upper protective layer, a translucent reflection layer and a thermal diffusion layer (light transmitting layer). The information layer on the innermost side comprises a lower protective layer, a phase-change recording layer, an upper protective layer and a reflecting layer; and each of thermal diffusion layers (light transmitting layers) of the information layers, other than the information layer on the innermost side, has In oxide, Zn oxide, Sn oxide and Si oxide. If the contents thereof are represented by "a", "b", "c" and "d" [mol%], respectively, the following requirements are satisfied; and if the refractive index of the first and second substrates is represented by "n", the laser light wavelength is represented by "λ" and the depth of the groove guides of the first and second substrates is represented by H, the requirements 3≤a≤50, 0≤d≤30, a+b+c+d=100 and λ/17n≤H≤λ/11.5n are satisfied. <P>COPYRIGHT: (C)2008,JPO&INPIT |
