OPTICAL DISK, ITS SUBSTRATE AND ITS MOLDING DIE

摘要

PROBLEM TO BE SOLVED: To make thin the thickness of an optical disk on which a clamp plate is disposed and make its outside diameter small. SOLUTION: A clamp holding face 14, a handling face 12 on the outer peripheral side of the face 14 and an information face 13 on the outer peripheral side of the face 14 are formed on a substrate 11. The face 12 is formed to have an inclined plane by inclining its outer peripheral side toward the face 13. The resin at the end of the face 12 on the inner peripheral side is melted/ deformed to form a projecting part 43 so that the clamp plate 41 can be held. Since the top of the inclined plane is deformed, the lager projecting part 43 can be formed. As a result, the optical disk and the substrate having thinner thickness and smaller outside diameter can be obtained.