Patent ID: 7120105

Claim:
A recording medium in which a synchronous pattern is attached to each of divided data having a predetermined length to form a frame, a data part is constituted by 31 frames, a preamble part including a plurality of synchronous patterns is attached to a start portion of said data part and a postamble part including a plurality of synchronous patterns is attached to an end portion of said data part to form a cluster, and information is recorded to said recording medium in units of said cluster; wherein at least one of said plurality of synchronous patterns attached to said preamble part and said postamble part is different from those attached to said data part, and a plurality of synchronous patterns are attached to said data part, said plurality of synchronous patterns attached to said data part are arranged such that at least three of the following four criteria are satisfied, a sequenced arrangementof synchronous patterns attached to frames (n- 1 ) and n does not occur at two or more positions, a sequenced arrangement of synchronous patterns attached to frames (n- 2 ) and n does not occur at two or more positions, a sequenced arrangement of synchronous patterns attached to frames (n- 3 ) and n does not occur at two or more positions, and a sequenced arrangement of synchronous patterns attached to frames (n- 4 ) and n does not occur at two or more positions, wherein n is an integer that ranges from 0 through 31.