Patent ID: 8295144
Filing Date: 2012-10-23
Classification: G11B

Abstract:
1. An optical pickup device comprising: 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; wherein along a direction substantially coincident with a radial direction of said optical disc in relation to a substantial center of the branching element are arrayed at least two regions that do not include an area on a direction substantially coincident with a tangential direction of said optical disc in relation to the substantial center of the branching element; and wherein luminous flux which enters the at least two regions is arranged onto the photodetector, along a direction substantially coincident with the tangential direction of the optical disc.