| 摘要 |
PURPOSE:To obtain an optical memory medium easy for tracking and excellent in the S/N, by burrying information track guide grooves formed on a transparent base with a material different from refractive index of the base to obtain a flat plane, and providing an optical recording layer on it. CONSTITUTION:On a transparent plastic base 1 (refractive index, n1) providing guide grooves 2 at the location of information track, a coating layer 3 (refractive index, n2) formed by burrying the grooves 2 with plastic different in the refractive index from the base 1, is provided, and an optical memory medium is made by forming a recording layer 4 on it. As said plastic material, it is preferable to use polymethyl methacrylate (n1=1.49) for the base 1, vinyl acetate (n2=1.45) and polyester resin (n2=1.54) for the coating layer 3. |
