| 摘要 |
PROBLEM TO BE SOLVED: To obtain a liquid crystal panel capable of effectively compensating wave front aberration on information recording surface even in the case of causing positional deviation between an objective lens and a liquid crystal panel. SOLUTION: This liquid crystal panel is arranged on the optical path of the light beams for a recording and a reproducing and the wave front aberration caused within the irradiation range of the light beams on the surface caused by the tilt between the optical axis of the beams and the information recording surface of a DVD is compensated by giving a phase difference to the beams. A transparent electrode 10c applies voltages to liquid crystals included in the panel. The electrode 10c is constituted of plural pattern electrodes 30a, 30b, 31a, 31b and 32 corresponding to the shapes of the distribution of the wave front aberration to be compensated. The shapes of the electrodes are formed to compensate the wave front aberration caused within the irradiation range when the preset radial direction positional deviation exists between the central axis of an objective lens and the central axis of the panel. |
