| 摘要 |
A first electrode of a liquid crystal cell (21) is composed of a plurality of concentric electrodes (31 to 34) of a concentrically circular shape, the plurality of concentric electrodes are divided into a first group of concentric electrodes (44) near the center and a second group of concentric electrodes (45) near the periphery, and a concentric electrode between the two groups is an independent single electrode (36). A first correction unit that corrects spherical aberration of a high density DVD is composed of the two groups and a second correction unit that corrects aberration of a conventional DVD is composed of the first group of concentric electrodes (44). In the case of correcting the aberration of the conventional DVD, the independent concentric electrode (36) is supplied with a voltage between the voltages respectively supplied to adjacent concentric electrodes (35), (37). In the case of correcting the aberration of the high density DVD, the independent concentric electrode (36) is supplied with a voltage equal to the voltage supplied to the concentric electrode immediately lateral thereto (37).
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