US Patent 7475327 Optical disc recording and reproducing apparatus

When an ECC error correction fails in both VMGI and VMGI_BUP, when the ECC error correction failed due to damage of PI in VMGI and PI for the same portion in VMGI_BUP is intact, in a case where the ECC error correction succeeds by using PI in VMGI_BUP as PI in VMGI, the ECC error correction succeeds by merging with a portion where the ECC error correction succeeded, or the ECC error correction succeeds by estimation based on the file size for the portion where the ECC error correction failed even by the merging and in a case where a re-writable optical disc is used, a correct management information file is newly written at an address different from the originally assigned address.