Patent ID: 7626909
Filing Date: 2009-12-01
Classification: G11B

Abstract:
1. An optical recording medium in which a write-once or rewrite operation of data can be performed with a block including a group of data as a unit, wherein buffer areas having a fixed length for random access are respectively disposed before and after respective blocks, whereby when a new block is recorded a start point for the fixed length buffer area before the new block is not fixed relative to an existing block preceding the new block, and the new block is recorded in a state that the fixed length buffer area provided with respect to the new block and the fixed length buffer area provided with respect to the existing block adjacent to the new block overlap with each other, wherein the fixed length buffer area disposed immediately before a respective of the blocks includes a preamble for signal processing, and plural synchronization patterns having distances and identification information that are different from each other are recorded at the preamble.