Patent ID: 8102748

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 angle adjustment element moving in a direction of an optical axis to change a spread angle of laser light emitted from the laser light source; and a converging lens part for converging the laser light having passed through the angle adjustment element onto the disc, wherein with the laser light in a parallel state having passed through the angle adjustment element, if a distance L 1 between the laser light source and the angle adjustment element and a distance L 2 between the angle adjustment element and the converging lens are in a relation of L 1 <L 2 , the converging lens part is configured to bring the incident parallel laser light into focus with minimum spherical aberration at a designed focal position on the inner side of an intermediate position between the foremost and innermost recording layers; and if the distances L 1 and L 2 are in a relation of L 1 >L 2 , the converging lens is configured to bring the incident parallel laser light into focus with minimum spherical aberration at a designed focal position on the front side of the intermediate position.