OPTICAL DISK, OPTICAL DISK MANUFACTURING METHOD, OPTICAL DISK RECORDING/REPRODUCING APPARATUS, AND OPTICAL DISK RECORDING/REPRODUCING METHOD

摘要

PROBLEM TO BE SOLVED: To make it difficult to forge an optical disk and to make it substantially impossible to forge the optical disk by making the burden for forgery imposed on a forger side tremendous even if forgery is possible.

SOLUTION: When silica fine particles are disposed on a signal surface 1 of the optical disk to form a photonic crystal layer 2, distribution spots of the silica fine particles are formed at random. The distribution spots can be used as an intrinsic information for identifying every one optical disk since the distribution spots are different at random in every optical disk. Thereby, it can be made substantially impossible to forge the optical disk since it is impossible to manufacture the optical disk having the same distribution spots by controlling the disposition of the silica fine particles and even if it can be made possible, the tremendous burden is unprofitably imposed on the forger side.

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