Optical pickup device and optical disc apparatus

摘要

An optical pickup device includes a semiconductor laser for emitting laser light, an objective lens for irradiating luminous flux emitted from the semiconductor laser to an optical disc, a branching element having a plurality of regions for branching luminous flux reflected from the optical disc to a plurality of fluxes, and a photodetector having a plurality of light receiving parts which receive luminous flux branched by said branching element. Luminous flux which enters at least two regions arrayed along a direction which is made substantially coincident with a tangential direction of the optical disc in regard to substantially a center of the branching element is arranged along a direction which is made substantially coincident with a radial direction of the optical disc on the photodetector.