OPTICAL PICKUP DEVICE HAVING SPHERICAL ABERRATION CORRECTING APPARATUS, AND ITS SPHERICAL ABERRATION CORRECTING METHOD

PROBLEM TO BE SOLVED: To provide an optical pickup device provided with a spherical aberration correcting apparatus which can correct spherical aberration caused in a process, in which a laser beam emitted from a light source is made incident on an optical recording medium and in a process in which the laser beam is reflected by the optical recording medium, and to provide its spherical aberration correcting method. SOLUTION: Spherical aberration of the laser beam, emitted from the light source and made incident on the optical recording medium and the laser beam reflected by the optical recording medium and made incident again can be corrected, by adopting a spherical aberration correcting apparatus, constituted of a wave plate which converts the phase of beams entering the wave plate and outputting it and a liquid crystal panel having a liquid crystal molecular structure for adjusting the phase of circularly-polarized beams. Thereby, jitter characteristic of the optical pickup device can be improved. COPYRIGHT: (C)2005,JPO&NCIPI