| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical information recording medium having a protrusion for protecting a transparent protective layer and reducing a load on a motor during disk rotation, and obtaining higher disk holding force.SOLUTION: The optical information recording medium includes a signal substrate, a signal recording layer, and a transparent protective layer disposed over the signal recording layer, and includes a center hole, wherein recording and reproducing of information is conducted by irradiating the signal recording layer with light through the transparent protective layer. The optical information recording medium includes a holding area in an area between a signal area corresponding to the area on which the signal recording layer is formed and the center hole, and includes the protrusion projecting from a surface of the transparent protective layer on the light-incidence surface side in an area between the center hole and the holding area. |
