| 摘要 |
PROBLEM TO BE SOLVED: To suitably correct the influence of aberration owing to an information recording medium. SOLUTION: An aberration correcting optical element 4 for correcting aberration is arranged in an optical path between a light source emitting information recording or information reproducing light and an objective lens. Electrode parts 12, 13 holding a liquid crystal element 14 are provided in the aberration correcting optical element 4, and mutually facing relational transparent electrode layers A1-Ai, B1-Bj, C1-Ci, D1-Dj are formed in these electrode parts 12, 13. Further, these transparent electrode layers A1-Ai, B1-Bj, C1-Ci, D1-Dj are formed with a multilayerd structure along the liquid crystal element 14 side. Owing to such a multilayerd structure, the transparent electrodes B1-Bj are faced to gaps W1 formed among the transparent electrode layers A1-Ai, and the transparent electrodes D1-Dj are faced to gaps W2 formed among the transparent electrode layers C1-Ci. Thus, all transparent electrodes are faced to the liquid crystal 14 without any gaps, the change of oriented stats is caused within the liquid crystal 14 without any gaps, and whereby aberration correcting precision is improved. |
