| 摘要 |
PURPOSE: A liquid crystal optical shutter is to lower a driving voltage, to enhance a high-speed response properties and maximum contrast ratio, and to simultaneously increase a shock resistance. CONSTITUTION: The liquid crystal optical shutter comprises a light control layer between two sheets of transparent conductive substrates. The light control layer is formed by covering a cholesteric liquid crystal, a chiral smectic C liquid crystal or a mixture thereof with a polymer coating. The polymer coating is prepared from a photo-polymerization of a prepolymer containing urethane acrylate. The prepolymer comprises 20 to 60 wt% of urethane acrylate relative to its total weight. Further, 3 to 30 wt% of prepolymer, with respect to the total weight of the light control layer, is included in the layer. The shutter shows a driving voltage of 4 to 8V, a rising time of 4 to 10 ms, a decaying time of 4 to 13 ms, a transmittance of more than 90%, and a maximum contrast ratio of more than 120. |
