| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device having a large chromatic aberration correction function achieve stable tracking, and to provide an optical system. <P>SOLUTION: A flux of rays from a light source is converted onto an information recording medium to form a spot, to perform at least one of information reading, writing and erasure and is used by an optical pickup device. The optical pickup lens device includes, in the order from the light source side, a collimating lens for converting a flux of rays into parallel rays or convergent or divergent rays, the collimating lens being movably held along a direction of an optical axis of a flux of rays emitted from a light source; an aberration correcting element for allowing a flux of rays emitted from the collimating lens to be transmitted therethrough; and an objective lens element having a numerical aperture of 0.8 or more, and converging a flux of rays coming from the aberration correcting element onto the information recording medium to form a spot. The aberration correcting element has a diffraction face having power which deflects a flux of rays by diffraction, and the aberration correcting element and the objective lens element are integrally held together in a direction orthogonal to the optical axis so as to perform tracking on the information recording medium. <P>COPYRIGHT: (C)2009,JPO&INPIT |
