Error correction device of optical disk unit

An error correction device of an optical disk reproduction unit for reproducing recorded information from an optical disk recorded with a first code row data added with an error code in the same direction as a sequence of recorded information in a recording portion of the optical disk and with recorded guide information recorded in advance in an inerasable state before said first code row is recorded as a recorded guide for recording said first code row data in said optical disk, comprising:

• a first position detection portion configured to detect a physical configurational singular point in said recorded guide information as a first position;
• a second position generating portion configured to generate a second position replacing said first position detected by said first position detection portion with said first code row data position;
• an error detection portion configured to detect a data error of said second position;
• and
• an error measurement portion configured to measure the number of errors detected by said error detection portion,
• wherein, when the number of errors measured for a predetermined period by said error measurement portion satisfies a predetermined value, errors of said first code row data are erasure-corrected by using said second position.