| 摘要 |
PURPOSE:To form good pits in a short time or with low recording power by providing a recording layer on a transparent substrate, covering the recording layer with a thin layer and then heating the recording layer by irradiating with a radiation beam so as to deform the thin layer to the opposite side of the substrate and to record informations. CONSTITUTION:The recording layer 2 consists of water-insoluble material, for example, such as cyanine color, and the thin layer 3 consists of water-soluble resin such as polyvinyl alcohol formed thereon and is subjected to polymerization treatment to be water resistant. By this constitution, the recording layer 2 is locally molten thermally by the radiation beam to form vacancies 19 for signals. During this process, vaporized matter can not escape from the vacancy because of the thin layer 3, and consequently, it swells the thin layer toward outside a little and maintains proper inner pressure of the vacancy. Diffusion of molten matter is promoted, and pits are formed rapidly and preferably. Thus, recording sensitivity can be improved. |
