Optical pickup apparatus having a bisected optical receiving element for tracking control

摘要

An optical pickup apparatus including: an irradiation optical system for irradiating a light beam to at least one track of a recording medium carrying a recorded signal to be read, an image formation device for preforming an image formation of a real image for the recorded signal or track of the recording medium to make an image surface by using a reflected light from an irradiated portion of the light beam, and a photodetector for detecting the reflected light and having an optical receiving element disposed on the image surface. The optical receiving element has at least one first optical receiving element for tracking control which is bisected in a track image direction formed on the image surface such that the first optical receiving element has a width in a perpendicular direction to the track direction smaller than a distance represented by twice a track pitch in a track image formed on the first optical receiving element less a width of the track image. The optical receiving element further includes at least one second optical receiving element of signal-reading disposed adjacent to the first optical receiving element in the track image direction. The optical pickup apparatus is thus capable of stably reading a recorded signal from the optical disk and of stably performing a tracking operation by its simple construction.