| 摘要 |
PROBLEM TO BE SOLVED: To prevent idle running when an optical recording medium having a clamp reference surface set in a part on one main surface of a light transmissive layer is clamped and rotated. SOLUTION: An optical disk is provided with an information signal part 1c for recording and/or reproducing an information signal on one main surface of a disk substrate 1, and a light transmissive layer 2 for transmitting a laser beam used for recording and/or reproducing the information signal on the side of the information signal part. A clamp reference surface 3a is set on the clamp area 3 of the light transmissive layer 2, and at least a part of the clamp reference surface 3a is formed to have a rough surface. Surface roughness Ra on the clamp reference surface 3a is set to 120 nm or higher, and its dynamic friction coefficient is set to 0.5 or higher. |
