| 摘要 |
PURPOSE:To vary the refractive index of a liquid-crystal lens cotinuously by applying an external electric field or magnetic field to a cyanobiphenyl liquid- crystal cell which is in the shape of a lens and has liquid-crystal molecules oriented in one direction, and controlling the orientation state of the liquid- crystal molecules. CONSTITUTION:When an AC voltage is applied to the liquid-crystal cell wherein field-effect liquid crystal with positive dielectric anisotropy is charged between two transparent electrode substrates and liquid-crystal molecules are oriented in parallel to the substrates, the liquid-crystal molecules change direction continuously at right angles to the substrates at an applied voltage higher than a threshold value, and the apparent refractive index of the liquid-crystal cell varies from a value for abnormal light to a value for normal light with incident light polarized in the orientation direction of the liquid-crystal molecules. For the purpose, the lens 3 is formed by using the field-effect liquid crystal which is oriented in parallel and has positive dielectic anisotropy, and liquid-crystal molecules are slanted with the applied voltage 5 to vary the apparent refractive index of the liquid-crystal cell, varying the focal length of the lens 3 continuously. |
