Patent ID: 8159906

Claim:
An address generating method for a recording medium having an area for recording data regarding structure of recording layers and clusters, and addresses indicating physical recording positions on the recording medium, the addresses including layer number addresses indicating numbers of the recording layers, cluster number addresses indicating data positions of the clusters, and in-cluster count values for counting inside of each of the clusters, the method comprising the steps of: generating the addresses based on either of a first bit allocation and a second bit allocation; forming the first bit allocation from a layer number address of h bits (h: natural number), a cluster number address of i bits (i: natural number) and a count value of j bits (j: natural number); arranging the first bit allocation to an address bit of (h+i+j) bits on the recording medium; and forming the second bit allocation from a layer number address of h bits, a cluster number address of (i+k) bits (k: natural number) and a count value of j bits, the second bit allocation having a virtual bit which is not recorded in the recording medium, wherein the virtual bit indicates whether a regularity of lower two bits is a repetition of an increment, are used as extended bits of the cluster number addresses, and are arranged to an address bit of (h+i+j) bits on the recording medium by virtually embedding the virtual bit.