Patent ID: 6922387
Filing Date: 2005-07-26
Classification: G11B

Abstract:
1. A recording/reproducing method for an optical information recording medium for recording, reproducing or erasing information by irradiating an optical information recording medium with laser light, the optical information recording medium comprising a disk-shaped transparent substrate and a recording layer for recording, reproducing or erasing information by irradiation of laser light, the recording layer being formed over the substrate, wherein the recording layer comprises information tracks, the information tracks comprise information recording regions and address regions interposed between the information recording regions, the information recording regions and the address regions being arranged along the tracking direction of the laser light, prepit addresses for providing information on a position on the recording medium are formed on the address regions, and no pair of adjacent address regions in the radial direction of the disk are arranged so as to be aligned on a straight line passing through a center of the disk, the method comprising: detecting reflected light obtained by irradiating the recording medium with the laser light by a photodetector including two light-receiving portions divided in a direction corresponding to a tracking direction of the laser light; generating a sum signal and a difference signal of electrical signals output from the two light-receiving portions; generating a corrected sum signal obtained by correcting an amplitude variation of the sum signal with the difference signal; and generating data information from the corrected sum signal, thereby reproducing the information.