IMPROVED MULTI-LAYER OPTICAL DISC FORMAT

摘要

An optical disc (102) and method for forming the same. The optical disc preferably includes a first substrate (15 0) comprising a pre-recorded, first data storage layer (152) and a second substrate (156) comprising a recordable, second data storage layer (158). The second substrate is affixed to the first substrate such that a data transducing beam (16 1) passes through a common exterior boundary surface (162) of the disc to access the respective first and second layers. Preferably, the pre-recorded layer comprises a sequence of pits and lands (218). Addresses of blocks in the respective layers preferably successively increment (220) so that a readback system (100) interprets the respective layers as a common recording layer within the disc. One of the layers can store disc authentication data zone, a patch which updates a version of user data stored in the remaining layer, etc. A content supplier can supply specially configured substrates with pre-recorded control data to control disc manufacture.