Optical pickup device

摘要

An optical pickup device has a variable-shape mirror (6) that reflects a light beam emitted from a light source and that, by use of piezoelectric elements (13) sandwiched between a support substrate (11) and a mirror portion (12) arranged to face the support substrate, corrects for wavefront aberrations in the light beam by deforming a mirror surface of the mirror portion, and converging means for directing, while condensing, the light beam reflected from the variableshape mirror to a recording surface of an optical recording medium. Let a direction perpendicular to the travel direction of the light beam emitted from the light source be the X direction on the mirror surface and let the direction perpendicular to the X direction be the Y direction on the mirror surface, the mirror surface is inclined about the X direction such that the mirror surface forms a predetermined angle relative to the travel direction of the light beam emitted from the light source. The piezoelectric elements are arranged symmetrically about the center axis of the mirror surface, with two of them arranged in the X direction and another two in the Y direction. The piezoelectric elements are arranged on the support substrate such that, when all of them are driven with equal voltages, the curvature of the mirror surface in the X direction relative to the curvature of the mirror surface in the Y direction fulfills a predetermined curvature ratio.