An optical disk and an optical disk recording/reproduction device

摘要

An optical disk (1) of a land (111) groove (110,112) recording/reproduction type comprising a plurality of sectors having a sector address region (5) and a data region (6,7) wherein
   the sector address region (5) includes a plurality of address blocks (114-120), at least two (117,118,119,120) of the plurality of address blocks that adjoin each other along a circumference direction being disposed so as to be shifted toward opposite sides with respect to a track centre, and
   each of the plurality of address blocks (114-120) includes within the sector address region (5) a portion (302,307) indicating an address number for identifying the plurality of sectors from one another and a portion indicating an ID number for identifying the plurality of address blocks (114-120) from one another, and
   the first one (117) of the plurality of address blocks includes a reproduction clock synchronization signal portion (VFO) which is longer than or equal to a reproduction clock synchronization signal portion (VFO) of any other address block (118-120).