Patent ID: 6137758
Filing Date: 2000-10-24
Classification: G11B

Abstract:
An optical disc discriminating apparatus comprising:optical means for irradiating a main beam and a pair of sub-beams onto an optical disc to read a signal recorded thereon, the optical means having a pair of sub-beam detectors for detecting the sub-beams reflected from the optical disc to generate detection signals;a first detector to detect a phase difference between the detection signals;judging means for judging a type of the optical disc on the basis of comparison at least between the phase difference and a reference phase difference, the optical means conducting tracking servo control on the basis of the detection signals after the judgement is made;an adjuster to adjust gains and offset levels of the detection signals; andmeans for binarizing the detection signals the gains and offset levels of which have been adjusted, the first detector detecting the phase difference between the binarized detection signals.