| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a spherical aberration correction plate capable of preventing the occurrence of undesirable optical axis shift when correcting spherical aberration, and an optical pickup device provided with the spherical aberration correction plate. <P>SOLUTION: The spherical aberration correction plate 19 has a first correction plate 31, a second correction plate 32 and a third correction plate 33, and the second correction plate 32 is movable in a direction orthogonal to an optical axis by a driving means. Regardless of the movement of the second correction plate 32, distances between an inclined surface 31b and an inclined surface 32a and between an inclined surface 32b and an inclined surface 33b are kept the same and the extending directions of the inclined surface 31b and the inclined surface 32a and the inclined surface 32b and the inclined surface 33b are maintained in parallel respectively. Thus, the occurrence of the optical axis shift is prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT |
