| 摘要 |
PURPOSE:To obtain the titled optical memory medium capable of performing multiple recording and reproduction with high sensitivity and high density by dispersing >=2 kinds of fine metallic blocks having different wavelength showing a light absorption maximum into a hold-back body (a binder) reacting with the metallic block by the irradiation of the light having specified wavelength. CONSTITUTION:A block of a single fine particle or aggregated fine particles of Ag having the high absorption maximum at 430nm and Au having the maximum at 560nm and having respectively 10-1,000Angstrom diameter, for example, is dispersed in a reactive binder such as an ethylene-acrylic acid copolymer and an epoxy resin wherein the light absorption maximum is vanished by the reaction of the metallic fine particle with the binder under the irradiation of an excimer laser beam 1 of 350nm wavelength to obtain a recording layer 8 which is formed on a substrate 7. When the excimer laser beam 8 is irradiated on the memory medium thus obtained, the respective absorption maxima of the respective metals are vanished at the irradiated part 91, whereas the absorption maximum at the unirradiated part 92 is not vanished. When an XeF laser is irradiated, only the absorption maximum of Au remains at the irradiated part, and only the absorption maximum of Ag remains, when a KrF laser is irradiated. By utilizing the phenomenon and selecting the wavelength of the recording and reproducing light, a memory medium 6 capable of recording and reproducing in three ways is obtained. |
