| 摘要 |
PURPOSE:To improve repetitive durability of recording and erasing and to upgrade reliability such as weatherability by providing heat-resistant protective layers consisting of silicon carbide on both sides of a recording layer. CONSTITUTION:The protective layers 2, 4 consisting of the same kind of the compsn. having the refractive index smaller than the refractive index of the recording layer are provided on both sides of the thin film-like recording layer 3 which is heated up and is changed in the optical constant thereof by irradiation of light; further, base materials 1, 5 consisting of the same kind of the compsn. having the refractive index smaller than the refractive index of the protective layers on the outside surfaces of both protective layers. The entire part or essential component of the protective layers is constituted of silicon carbide. The counter diffusion of atoms between the protective layers and the recording layer is thereby eliminated and the recording layer is stabilized, by which the durability for repeating the recording and erasing by irradiation of layer light is remarkably improved and the damage of the base materials is prevented during the repeated use of recording and erasing by the irradiation of laser, by which the increase of a noise level is suppressed. The deterioration of C/N is thus decreased. The penetration of the moisture in the atm. into the recording layer is shut off, the deterioration in the film quality of the recording layer is suppressed, the moisture resistant characteristic is remarkably improved and the longer life is made possible. |
