Patent ID: 6829208
Filing Date: 2004-12-07
Classification: G11B

Abstract:
A reproduction method of an optical disc, comprising: a step of scanning a pit sequence recorded on the optical disc with a laser beam and detecting an intensity of reflected light from the optical disc by detectors formed by a plurality of light-detecting elements so as to generate detection signals; and a step of generating reproduction data based on the detection signals, whereinthe detectors are grouped into a first light-detecting element group and a second light-detecting element group with respect to a scanning direction of the laser beam, and the reproduction method includes steps of: performing an addition operation on a detection signal obtained by the first light-detecting element group and a detection signal obtained by the second light-detecting element group so as to generate a summation signal and outputting the summation signal to a signal processing section; performing a difference operation on a detection signal obtained by the first light-detecting element group and a detection signal obtained by the second light-detecting element group so as to generate a differential signal and outputting the differential signal to the signal processing section; digitalizing the summation signal by the signal processing section so as to generate a binary signal, and generating a binary signal edge pulse which corresponds to a rising edge or a falling edge of the binary signal; only when an amplitude which is equal to or greater than a predetermined value of the differential signal is detected, outputting the binary signal edge pulse as a reproduction edge pulse which corresponds to an edge of the pit from the signal processing section; and generating the reproduction data based on the reproduction edge pulse.