| 摘要 |
PROBLEM TO BE SOLVED: To effectively correct aberration caused by changes in the depth from the surface of the optical recording medium to the point where light is to be condensed even when the depth varies, by disposing a device comprising two liquid crystal layers having stripe electrodes stacked with the electrodes perpendicular to each other on the way of the optical path of an illuminating optical system. SOLUTION: A liquid crystal device 10 is disposed at the back of an objective lens 15. The liquid crystal device 10 has a structure of a first liquid crystal layer 102 interposed between glass substrates 101, 103 and a second liquid crystal layer 104 interposed between glass substrates 103, 105. Each of the first and second liquid crystal layers 102, 104 is interposed between transparent plural first and second electrodes which are extended in the X or Y direction and arranged in the Y or X direction, respectively, and a transparent solid electrode. The driving circuit 50 is used to apply controlled voltage on each between the plural first or second electrodes and the solid electrodes of the liquid crystal device 10 to correct the aberration of the condensed light on an optical disk. |
