| 摘要 |
PURPOSE:To dissolve deviation of image forming points relying on the polarizing direction, by variably controlling the length of an optical path by combining two optical elements whose molecule oriented directions become opposite to each other on a plane vertical to the optical axis and changing an applied voltage. CONSTITUTION:Liquid crystal lenses 12a and 12b are formed by enclosing liquid crystal 16 in the hollow cells between one surfaces of adjacent transparent plates 13 and a concave lens 15 and an AC voltage is applied across a pair of transparent electrodes 17 and 18. When the orienting directions of liquid crystal molecules 21a and 21b are made opposite the each other about a plane intersecting the optical axis at right angles and the sizes of the orienting directions are made equal to each other by applying the same voltage across the liquid crystal lenses 12. The molecules 21a and 21b are oriented in a rightward-descending and rightward-descending conditions, respectively. There fore, deviation of image forming positions can be dissolved and, at the same time, the focal distance can be changed by changing the applied voltage, since the advancing course of the abnormal light Le of rays made incident along the optical axis is deviated upwar and then returned to the original condition.
|
