| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress aberration even when an optical axis of an objective lens deviated from that of a color correction element. <P>SOLUTION: An information signal is recorded or reproduced by irradiating a light along a track of a rotating optical disk. The objective lens 25 which controls a movement in the radial direction of the optical disk so that a condensing light may be irradiated along the track of the optical disk, a fixed triplet 24 which makes compensation for chromatic aberration of the objective lens 25, and a fixed expander which makes compensation for spherical aberration of the objective lens 25 are provided. The triplet 24 compensates an error component of the focal direction caused by the chromatic aberration. <P>COPYRIGHT: (C)2003,JPO |
