OPTICAL DISK DRIVE, TILT CORRECTION METHOD, AND PROGRAM

• Main Author: SAGARA SEIICHI
• Format: Patent
• Language: English
• Published: 07.01.2013
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

PROBLEM TO BE SOLVED: To improve the accuracy of tilt correction performed in an unrecorded area.SOLUTION: Difference information (for example, ratio information) between a tilt adjustment value for making an evaluation value based on a playback signal the best and a tilt adjustment value for making a push-pull signal the maximum is calculated in advance, the tilt adjustment value for making the push-pull signal the maximum is retrieved in the unrecorded area, and the tilt adjustment value is corrected by the difference information to perform tilt correction. In such a case, if focus bias values respectively set between when the difference information is calculated and during tilt retrieval in the unrecorded are different, accurate tilt correction cannot be performed. Therefore, the difference information is calculated under a setting condition of a focus bias value calculated by the same method as a retrieval setting method of a focus bias value during actual tilt retrieval in the unrecorded area. Consequently, tilt correction using the difference information can be performed with higher accuracy.