Patent ID: 8023387

Claim:
An optical pickup device for recording and/or reproducing information onto and/or from a disc having a plurality of recording layers in a direction of lamination, comprising: a laser light source; an objective lens for allowing light emitted from the laser light source to converge onto the disc; an astigmatic element for allowing the laser light reflected by the disc to converge in a first direction and form a first focal line at a first position and allowing the laser light to converge in a second direction and form a second focal line at a second position closer to the disc than the first position; a spectral element for splitting a flux of the laser light having passed through the astigmatic element in two along a straight line parallel to the first direction and separating traveling directions of split light fluxes from each other; and a photodetector for receiving the laser light having passed through the spectral element, wherein the spectral element is interposed between the second focal line of the laser light reflected from a target recording layer in the disc and the second focal line of the laser light reflected from a deeper recording layer than the target recording layer, and the photodetector is interposed between the first and second focal lines of the laser light reflected from the target recording layer.