Data recording media and recording/reproduction thereof

摘要

High-speed access to a multi-layered disk is to be realized. Each layer on a multi-layered disk may include an inside guard area 2, program area 3, and outer guard area 5 which are located in uniform radial positions in all layers. The uppermost layer has the recording direction from the inner side to the outer side of the disk, and the next layer has the recording direction from the outer side to the inner side of the disk such that opposite recording directions appear alternately. The radial position of the recording terminal end on the uppermost first layer may coincide with the radial position of the start of record on the next second layer. Recording and/or playback apparatus for such recording media is also provided.