Patent ID: 7680004

Claim:
A method of performing an inverse non-linearity compensation, comprising: providing a plurality of photodetectors, each photodetector configured to provide a photodetector signal in response to receiving reflected light from an optical disk, the plurality of photodetectors thereby providing a plurality of photodetector signals; receiving at a digital signal processor a digitized version of each of the photodetector signals in the plurality of photodetector signals; in the digital signal processor, forming a digital focus error signal and a tracking error signal from the digitized versions; adjusting the digital focus error signal with an offset value to form a digital offset focus error signal; providing a gain to amplify the digital offset focus error signal so as to produce an amplified digital offset focus error signal, wherein the gain is based on the offset value such that the amplified digital offset focus error signal is substantially linear; and amplifying the digital offset focus error signal with the gain to produce the amplified digital offset focus error signal.