Patent ID: 7304918

Claim:
A servo error signal generation circuit for generating a servo error signal using reflected light from an optical disc, which is detected by plural photoreceptors, said circuit comprising: a first sampling unit for sampling, at first sampling timings, first detection signals which are outputted from the plural photoreceptors; a sub sampling timing generator for periodically thinning out the first sampling timings to generate second sampling timings having a reduced sampling frequency; a second sampling unit for sampling, at the second sampling timings, second detection signals which are outputted from plural photoreceptors and assist or correct the first detection signals; an AD converter for analog-to-digital converting the data which have been sampled by the first sampling unit and the second sampling unit; and a completion unit for completing the data of the timings which have been thinned out by the sub sampling timing generator, among the data which have been sampled by the second sampling unit and outputted from the AD converter.