| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical recording medium suitable to multi-level recording. SOLUTION: In the optical recording medium on which information is recorded by irradiating laser beams, plural virtual recording cells having the prescribed length are continuously defined in the relative moving direction of the optical recording medium. When recording power required for changing 20% of the reflectivity variation width X-Y defined from the initial reflectivity X and the limit minimum reflectivity Y of the virtual recording cell from the initial reflectivity X by irradiating the laser beams is expressed by A and moreover the recording power required for changing 80% of the reflectivity variation width X-Y from the initial reflectivity X by irradiating the laser beams is expressed by B, the recording layer is set so as to become 1.8<(B-A)/A<11. Thus, irradiating power of the laser beams is switched into five stages or more to perform multi-level recording. |
