| 摘要 |
PURPOSE:To obtain an optical recording medium possible for repeated use with a heat mode, by providing an optical recording layer including light absorbing coloring matter or pigment on a polystyrene base having an average molecular weight within a specific range. CONSTITUTION:An optical recording medium is formed by coating and drying a coating liquid with 0.002-10wt% of a light absorbing coloring matter or pigment (to 1pt.wt polystyrene) to the polystyrene with 350-10,000 average molecular weight on a substrate such as glass and plastic. Pits, 1mu diameter, projected at the circumference, 0.2mu width and recessed at the center are formed at the recording layer by irradiating a He-Ne laser beam on the medium. The bottom of the pits does not reach the bottom of the layer, then the polystyrene and the coloring matter remain, the circumference is smoothed and reading can be made through transmitted or reflected rays through the irradiation of a weak laser beam. Since the uneven pints are molten again through reheating of the medium, erasing is made easy and the use of rewriting can repetitively be made possible. |
