| 摘要 |
PURPOSE: To obtain an optical recording medium capable of recording and reproducing four values at the same position as an optical recording medium used in an external recorder. CONSTITUTION: This optical recording medium has at least a magnetooptical recording film and a phase change type recording film on the substrate. The phase change type recording film has the practically same reflectance and mutually different apparent angles of Kerr rotation when the film has a crystal phase and when it has an amorphous phase. |
