DEVICE AND METHOD FOR CORRECTING AF OFFSET VALUE IN OPTICAL DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain an optimum AF(autofocus) offset value from a pre-pit mark regenerative signal even when a disk cartridge is write-protected. ;SOLUTION: In an optical disk device provided with the disk cartridge capable of on/off setting 103 of write-protecting, this correcting device is provided with first means 107 and second means 109 correcting a target offset value of an AF servo, and the first means 107 is provided with a function recording the correcting pattern of the target offset value and setting the optimum AF offset value from the data of the regenerative output of the recorded pattern, and the second means 109 is provided with the function setting the optimum AF offset value from the data of the regenerative output of a pre-pit pattern. Then, the correcting device detects the off setting of the write-protecting, and switches to the first means 107, and detects the on setting of the write- protecting, and switches to the second means 109 to correct the AF offset value.;COPYRIGHT: (C)1998,JPO