Patent ID: 7936654

Claim:
An optical disk device comprising: an optical pickup configured to selectively emit a plurality of laser beams of different wavelengths to an optical disk mounted in the optical disk device; a focus drive section configured to drive the optical pickup to move a focus position of the optical pickup in a direction perpendicular to the optical disk; a detection section configured to detect reflected light reflected from the optical disk while the focus drive section moves the focus position of the optical pickup; a time measurement section configured to measure a focus search time while the focus drive section moves the focus position of the optical pickup with the focus search time being a period between when the reflected light reflected from a disk surface of the optical disk is detected and when the reflected light reflected from an information recording layer of the optical disk is detected, and the time measurement section further configured to measure a false reflection search time while the focus drive section moves the focus position of the optical pickup with the false reflection search time being a period between when the reflected light reflected from the disk surface of the optical disk is detected and when false reflection light is detected, the false reflection light being detected when the focus position of the optical pickup is located at a position other than the disk surface and the information recording layer of the optical disk; and a disk identification section configured to calculate a ratio of the focus search time to the false reflection search time, and identify a type of the optical disk based on the ratio.