| 摘要 |
PURPOSE:To attain writing which obtains an output signal conforming to a CD format by providing a specific rigid layer which is more difficult to thermally deform than a substrate between a light absorbing layer accompanied by local thermal deformation due to the radiation of laser light and a light reflecting layer to reflect the laser light behind the absorbing layer. CONSTITUTION:A rigid layer 6 is interposed between a light absorbing layer 2 and a light reflecting layer 3. The rigid layer 6 is formed by the material which is more difficult to thermally deform than a substrate 1, and it provides at least one of characteristics of >=M100 in Rockwell hardness ASTM 785, and >=100 deg.C (4.6kg/cm<2>) in a thermal deformation temperature ASTM 648. Consequently, when the light absorbing layer 2 absorbs the laser light, radiates heat, and the local thermal deformation is generated, the surface of the substrate 1 absorbs the thermal deformation of the light absorbing layer 2, the substrate 1 surface is locally thermally deformed, and a pit 5 is formed. Thus, the recording conforming to the CD format is attained. |
