Patent ID: 8250415

Claim:
An optical disk reproduction apparatus for reproducing main information and sub information recorded on an optical disk, comprising: an optical head for reading a reproduction signal including the main information and the sub information based on a recording mark formed on the optical disk; a main information extraction unit for extracting the main information from the reproduction signal read with the optical head; and a sub information extraction unit for extracting the sub information from the reproduction signal read with the optical head, wherein the sub information extraction unit includes: a reproduction accuracy determination unit for determining a reproduction accuracy of the sub information; an error correction timing control unit for deciding a timing of starting error correction of the sub information according to the reproduction accuracy determined with the reproduction accuracy determination unit; and an error correction unit for starting the error correction of the sub information according to the timing decided with the error correction timing control unit, and wherein the sub information is repeatedly recorded a plurality of times in predetermined recording area units of the optical disk, the sub information extraction unit extracts the sub information based on an integral value obtained by integrating a detection signal detected for each of the predetermined recording areas, and the error correction timing control unit determines whether to start the error correction for each of the predetermined recording area units.