| 摘要 |
PURPOSE:To improve the number of rewriting times while maintaining an excellent recording sensitivity by constituting this optical recording medium of a protective layer formed of a low-thermal expansion type material having a low coefft. of thermal expansion and an antireflection layer formed of a high-refractive index type material having a high refractive index. CONSTITUTION:This optical recording medium is constituted of the low-thermal expansion type protective layer 21 which is formed of the low-thermal expansion type material having the low coefft. of thermal expansion and in which the light incident side protective layer 2 exists on a recording layer 3 side and the antireflection layer which exists on the substrate 1 side and is formed of the high-refractive index type material having the higher refractive index than the refractive index of the above- mentioned low-thermal expansion type protective layer 21. The coefft. of thermal expansion of the low-thermal expansion type protective layer in direct contact with the recording layer is small and, therefore, the thermal deformation quantity of the protective layer at the time of rewriting can be decreased in such a case, by which the phenomenon of the movement of the molten recording material in the recording layer is prevented as far as possible Since the antireflection layer having the high refractive index is used, the surface reflection is prevented and the light absorbance of the recording layer is improved. |
