| 摘要 |
<P>PROBLEM TO BE SOLVED: To keep a warpage angle in a usage environmental temperature range within a permissible range, in an optical recording medium. <P>SOLUTION: In the optical recording medium, a light transmission layer 4 is formed so as to cover a recording film 3 formed on one surface of a base material 2 and an adjustment layer 5 is formed on the other surface of the base material 2. The adjustment layer 5 is formed by using a resin material whose value obtained by multiplying the linear expansion coefficient and the Young's modulus of the adjustment layer 5 together is greater than the value obtained by multiplying the linear expansion coefficient and the the Young's modulus of the light transmission layer 4 together thinner than the light transmission layer 4. The adjustment layer 5 is formed in a prescribed thickness T3 by using the material having a prescribed linear expansion coefficient and a prescribed Young's modulus so that the difference between the internal stress generated when a half body 1b on the adjustment layer 5 side in the thickness direction of the optical recording medium works on a half body 1a on the light transmission layer 4 side in the direction parallel to one surface of the base material 2 associating with expansion or shrinkage of the optical recording medium 1 and the internal stress generated when the half body 1a on the light transmission layer 4 side works on the half body 1b on the adjustment layer 5 side associated with expansion or shrinkage satisfies the conditions of 3.3 MPa or lower in the temperature range of -10°C to 55°C. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
