| 摘要 |
PROBLEM TO BE SOLVED: To obtain a medium capable of recording and erasure repeated many times by forming a dielectric layer contg. at least lanthanum and boron. SOLUTION: This optical recording medium has at least a phase transition type optical recording layer and a dielectric layer on the substrate. A transparent resin such as polycarbonate or acrylic resin or glass may be used as the material of the substrate. A protective layer made of an optically transparent dielectric layer having a high m.p., a high softening point and a high decomposition temp., easy to form and having moderate heat conductivity is disposed in a prescribed thickness on the surface of the substrate. This dielectric layer contains at least lanthanum (La) and boron (B). Since LaB6 has great dependency of its absorption factor and extinction coefft. on wavelength, it is effective in controlling the absorption factor and reflectance of a multilayered film at the time of designing the thickness structure of the film by utilizing the interference effect of light. |
