Patent ID: 6023449
Filing Date: 2000-02-08
Classification: G11B

Abstract:
An optical pickup to access a disk having a recording surface, comprising:a light source to generate light;optical path changing means for changing the path of the light emitted from the light source;an objective lens to converge the light from the optical path changing means to form a light spot on the recording surface of the disk; anda photodetector having at least two light-receiving regions, wherein the light-receiving regions separately perform photo-electric conversion and receive the light which has passed through the optical path changing means and the objective lens and been reflected from the disk;wherein the light-receiving regions are separated from adjacent ones of the light-receiving regions by a predetermined distance so that a focus error signal offset due to spherical aberration caused by the optical pickup accessing the disk when the disk has a first thickness and when the disk has a second thickness greater than the first thickness is not greater than 10%, such that a center region of the light incident on the photodetector between the light-receiving regions is not received by the light-receiving regions.