Patent ID: 7656778

Claim:
A read-only recording medium comprising a plurality of predetermined data units, wherein one of the plurality of predetermined data units comprises a first data type and a second data type, the first data type including user data, and the second data type linking the first data type and not containing the user data, wherein the first data type comprises at least one error correcting code (ECC) data unit on which error correction is performed, the at least one ECC data unit comprises a plurality of sub-units, and a size of the second data type is the same as a size of each of the plurality of sub-units, wherein the second data type comprises identification information for detecting the second data type when the plurality of predetermined data units are reproduced, and wherein a total size of the first data type and the second data type is equal to a size of a predetermined data unit to be used in a writable recording medium, which is a counterpart of the read-only recording medium, the predetermined data unit comprising the user data and invalid data.