Optical recording/reproducing apparatus

摘要

An optical information recording/reproducing apparatus records information on and/or reproduces information from an optical recording medium and detects a focal error based on a reflected light beam from the optical recording medium. The apparatus includes an optical element which deflects a part of the reflected light beam to at least two positions excluding a central part of the reflected light beam, and a photodetector device having a plurality of photodetectors which respectively detect the deflected parts of the reflected light beam and output detection outputs. The focal error is detected based on the detection outputs of the photodetector device.