OPTICAL DISK, OPTICAL REPRODUCING DEVICE, AND OPTICAL RECORDING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a high-reliability optical disk which can be recorded and reproduced even if a clock mark is destroyed owing to a defect. SOLUTION: The optical disk has a recording track formed of multiple sectors formed concentrically or spirally. A sector is divided into segments, which each have a data area where data is recorded and a clock mark having a different light reflection factor from the data area. Then multiple synchronous patterns S are formed in the data area in the sector.