| 摘要 |
An optical disc discriminating apparatus has an optical pickup that irradiates a main beam and a pair of sub-beams onto an optical disc to read a signal recorded thereon. The optical pickup has a pair of sub-beam detectors for detecting the sub-beams reflected from the optical disc to generate detection signals. A tracking error signal is produced on the basis of a differential of the detection signals. A type of the optical disc is judged on the basis of comparison between an amplitude of the tracking error signal and a reference amplitude. Or, it is judged on the basis of comparison between an phase difference between the detection signals and a reference phase difference. The judgement under both amplitude and phase comparison is also preferable. The optical pickup conducts tracking servo control on the basis of the detection signals after the judgement is made. <IMAGE> |
