Split photo detector for detecting a central portion and a peripheral portion of a reflected light beam

摘要

An optical information reproducing method, for optically reproducing information recorded on a recording medium, irradiates the recording medium with a laser beam and detects the light returning from the recording medium. When the diffracted light returning from the recording medium is detected, the optical intensity distribution of the diffracted light is detected by a plurality of detectors to produce a plurality of signals, and the signals are calculated to produce a reproduced signal for detecting the information.