Optical pickup for adjusting focus error signal offset and having widely separated photodetector elements

摘要

An optical pickup which include a light source; an optical path changing portion to change a path of light emitted from the light source; an objective lens to converge the light from the optical path changing portion to form a light spot on a recording surface of a disk; and a photodetector having at least two light-receiving regions, preferably four light-receiving regions in a 22 matrix, which separately perform photo-electric conversion, for receiving the light which has passed through the optical path changing portion and the objective lens and been reflected from the disk. The light-receiving regions are separated by a predetermined distance, such that a center region of the light is not received by the light-receiving regions.