Patent ID: 7869321

Claim:
An optical disk device capable of loading a plurality of different kinds of optical disks for use with different laser wavelengths, comprising: a first laser source configured to emit laser light of a first wavelength, said first laser source suitable for operation with optical disks of a first kind; at least a second laser source configured to emit laser light of a second wavelength longer than said first wavelength, said second laser source suitable for operation with optical disks of a second kind; an objective lens arranged to receive laser light from either said first laser source or said second laser source; an actuator to adjust said objective lens; a spherical aberration corrector to correct spherical aberration of an incident laser beam; and means for determining, for an optical disk loaded in the optical disk device, whether said loaded optical disk is an optical disk of the first kind or an optical disk of the second, wherein: said spherical aberration corrector is set to a value which is appropriate for an optical disk of the first kind, and said objective lens is adjusted by said actuator to determine if said loaded optical disk is an optical disk of the first kind; and if said loaded optical disk is not an optical disk of the first kind, then said spherical aberration corrector is set to a value which is appropriate for an optical disk of the second kind, and said objective lens is adjusted by said actuator to determine if said loaded optical disk is an optical disk of the second kind