Patent attributes
A disk inspection apparatus for discriminating disks. The disk inspection apparatus has an ECC control section and a comparison section. The ECC control section measures the number of error corrections PIE and the number of error correction failures PIF in a predetermined section of the disk. The comparison section discriminates the disk as a disk with a deterioration in jitter characteristic when the minimum or the average of the PIE exceeds a first threshold value; discriminates the disk as a normal disk when the maximum of the PIF is equal to or smaller than a second threshold and the minimum or the average of the PIE is equal to or smaller than the first threshold value; and discriminates the disk as a scratched disk when the minimum or the average of the PIE is equal to or smaller than the first threshold value and the maximum of the PIF exceeds the second threshold value.