Patent ID: RE43179

Claim:
An optical disk drive for reading and writing data from/on multiple types of optical disks, the drive comprising: a motor to rotate one of the optical disks thereon; an optical head including a light source for radiating a plurality of light beams with mutually different wavelengths and a photodetector for generating an electrical signal based on at least a part of the light beam that has been reflected from the optical disk; and a control section for performing an operation of recognizing the type of the optical disk, a focus control operation and a tracking control operation by controlling the operations of the optical head and the motor, wherein the control section performs the steps of: (A) after the optical disk drive has been loaded with the optical disk and before the operation of recognizing the type of the optical disk is finished, presuming one of the multiple types of candidate optical disks, from/on which data is readable and writable using a light beam with the shortest wavelength among the candidate disks, to be the optical disk being driven by the motor now and radiating the light beam for the presumed type of optical disk from the light source; (B) rotating the optical disk at a rotational velocity that realizes a linear velocity that is higher than a standardized normal velocity when data is read from the presumed type of optical disk prior to a focus control; (C) starting the focus control in a situation where the spot of the light beam being formed on the optical disk is moving on the optical disk at the linear velocity that is higher than the normal velocity; and (D) performing the operation of recognizing the type of the optical disk by the light beam that has been reflected from the optical disk under the focus control.