FORMATION OF INTRINSIC ID IN DISK-SHAPED OPTICAL RECORDING MEDIUM AND DISK-SHAPED OPTICAL RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To make it possible to improve security with a simple method by bonding a first substrate recorded with first pattern information and a second substrate recorded with second pattern information to each other and forming the intrinsic ID of a recording medium in accordance with the pattern information by the combination. SOLUTION: The pattern information of a slit structure utilizing light transparency is formed at 90 deg. intervals in an inner peripheral part 12 separately from a recordable region 11. The slits are aluminum reflection films having opacity and high reflectivity and may be detected by a prescribed optical read- out device. The pattern information of the slit structure is formed at similar 90 deg. intervals and the two layers are bonded to each other. When bonding phase angle offsets random in a circumferential direction are generated in the two layers in a bonding stage and the detection of the reflected light is executed by the aluminum reflection films, the combination of the pattern information (1) and the pattern information (2) is obtained and is utilized as the intrinsic ID by using the pulse spacing.