Optical disk reproduction apparatus, optical disk reproduction method, reproduction processing device and reproduction processing method

An optical disk reproduction method for reproducing main information and sub information recorded on an optical disk, comprising:

• a reproduction signal reading step of 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 step of extracting the main information from the reproduction signal read in the reproduction signal reading step;
• and
• a sub information extraction step of extracting the sub information from the reproduction signal read in the reproduction signal reading step,
• wherein the sub information extraction step includes:
• a reproduction accuracy determination step of determining a reproduction accuracy of the sub information;
• an error correction timing control step of deciding a timing of starting error correction of the sub information according to the reproduction accuracy determined in the reproduction accuracy determination step;
• and
• an error correction step of starting the error correction of the sub information according to the timing decided in the error correction timing control step, 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 step 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 step determines whether to start the error correction for each of the predetermined recording area units.

A reproduction processing device for processing a reproduction signal including main information and sub information read based on a recording mark formed on an optical disk, comprising:

• a main information extraction unit for extracting the main information from the reproduction signal;
• and
• a sub information extraction unit for extracting the sub information from the reproduction signal,
• 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.

A reproduction processing method for processing a reproduction signal including main information and sub information read based on a recording mark formed on an optical disk, comprising:

• a main information extraction step of extracting the main information from the reproduction signal;
• and
• a sub information extraction step of extracting the sub information from the reproduction signal,
• wherein the sub information extraction step includes:
• a reproduction accuracy determination step of determining a reproduction accuracy of the sub information;
• an error correction timing control step of deciding a timing of starting error correction of the sub information according to the reproduction accuracy determined in the reproduction accuracy determination step;
• and
• an error correction step of starting the error correction of the sub information according to the timing decided in the error correction timing control step, 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 step 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 step determines whether to start the error correction for each of the predetermined recording area units.