Abstract:
Disclosed are techniques and systems for manufacturing an optical disc having a stochastic (i.e., non-deterministic) anti-piracy feature in the form of a multi-spiral structure, and for verifying the feature on the optical disc to authenticate the disc for playback. The multi-spiral structure may be comprised of multiple partially interleaved, and partially overlapping, spiral data tracks formed in a designated area of the optical disc. A process of forming the multi-spiral structure may include forming, in the designated area, a first spiral data track with first track pitch and a second spiral data track with second track pitch that is different than the first track pitch. The multi-spiral structure may be analyzed to determine verification parameters for verifying the multi-spiral structure, and those verification parameters may be encrypted so that they may be subsequently decrypted and used to verify the multi-spiral structure on a disc reading device.
Abstract:
An optical disk (10A) includes a substrate (18) comprising a recording layer (28) and a pregroove (16), which are formed in this order as viewed in a direction in which a recording and/or reproducing laser beam (32) is radiated, wherein the pregroove (16) includes a plurality of meandering portions (40). Each of the meandering portions (40) includes a first curved portion (44), which is curved toward a first groove (42a) disposed adjacently on one side of a land (36), and a second curved portion (46), which is curved toward the land (36) from a second groove (42b) disposed adjacently on the other side of the land (36). An expression, 0.8
Abstract:
An optical disc having a region with pre-recorded data and a recordable region, a method of fabricating the disc, a stamper for forming a disc master, and a recording device for use with the disc are disclosed. Data recorded in the recordable region may be used for activation of the disc, providing unique identification or enhancing program content on the disc.
Abstract:
The optical storage medium (1) comprises a substrate layer (2) and a data layer (3) with a mark/space structure arranged in tracks (T1-T6), wherein a sequence (Z1) of marks of a first track (T1) have a first width (w1), and a sequence (Z2) of marks of a neighboring track (T2) have a second width (w2) being different from the first width. The optical storage medium is in particular an optical disc (1), on which the tracks (T1-T6) are arranged as spirals, circular rings or segmented circular rings.