OPTICAL DISK, OPTICAL DISK DEVICE, ERROR CORRECTION FORMAT AND DATA RECORDING/REPRODUCING METHOD

摘要

PROBLEM TO BE SOLVED: To solve the problem that a lost flag can not be obtained when the state of no error apparently occurs in a 2nd error correction code in the occurrence of media defect, in the case the loss correction of a 1st error correction code is made by using the correction positional information of the 2nd error correction code. SOLUTION: Data different from data outputted by a demodulator when the amplitude of reproduction signal is lost, are arranged on the unused part of data of the 2nd error correction code, and the constitution is made so that the unused data part of the 2nd error correction code surely becomes error in the occurrence of the defect.