Patent ID: 8593919

Claim:
In an recording medium provided with a plurality of recording layers having areas where a plurality of clusters for recording data are recorded, the recording medium comprising: an address, which is recorded by being wobbling-superimposed on a track on which data is recorded in synchronization with the cluster, and configured to indicate information including identification of clusters and an intra-cluster position, wherein the address is configured to indicate physical recording position on the recording medium, and includes: a layer number address indicating numbers of the plurality of recording layers, a cluster number address indicating data positions of the plurality of clusters, and an intra-cluster count value for specifying a physical position of the cluster; a data structure, including twelve (12) bits of data including disc information, and being configured by dividing a block to which a first error correction code is added into a plurality of parts, and the address; a code string, generated by adding a second error correction code to the data structure, and recorded on the recording medium with the code string modulated; a virtual bit, configured to indicate whether or not the regularity of low-order 2 bits of the address is switched, and used as an expansion bit of the cluster number address, and is not recorded on the recording medium is virtually imbedded in the address, and whether or not the regularity of low-order 2 bits is a repetition of increments.