Patent ID: 7342867

Claim:
An optical head device for use with an optical recording medium having multiple data layers, said optical head device comprising: a light source operable to output light; focusing means for focusing light outputted from the light source onto a desired data layer of the optical recording medium having multiple data layers; a wavefront converter provided between the light source and the focusing means; driving means for driving the wavefront converter; aberration detecting means for detecting an aberration amount of a spot of the light focused on the desired data layer and sending a driving amount to the driving means for driving the wavefront converter to reduce the detected aberration amount; the driving means performing the driving of the wavefront converter according to the driving amount sent by the aberration detecting means in such a manner as to reduce the aberration amount detected by the aberration detecting means; and output controlling means for storing learned data indicating correlation between driving amounts of the wavefront converter and outputs of light of the light source, and controlling the light source so as to set the output of light outputted by the light source to an output of light indicated in the learned data as correlating to the driving amount sent by the aberration detecting means.