Patent ID: 7760603
Filing Date: 2010-07-20
Classification: G11B

Abstract:
1. A method to discriminate an optical disc type in an optical disc system which records and/or reproduces data to and/or from a plurality of optical discs having different recording capacities, the method comprising: radiating a laser beam onto a given one of the optical discs and measuring a track error signal obtained from light reflected by the given optical disc, the track error signal comprising a track error signal component, PP actual, generated by a push-pull (PP) method, and a track error signal component, DPD actual, generated by a differential phase detection (DPD) method; comparing the measured track error signal with a predetermined reference value, PP reference, corresponding to the PP actual, and a predetermined reference value, DPD reference, corresponding to the DPD actual; and discriminating a type of the given optical disc according to the comparison, such that if both the PP actual and the DPD actual are respectively less than the PP reference and the DPD reference, the optical disc is determined to be a high-density digital versatile disc (HD-DVD).