| 摘要 |
<p>An inverse twisted or super-twisted nematic liquid crystal device in which the alignment layers (22, 24) on the two sides are homeotropic so as to regularly cause the associated linear liquid-crystal molecules (16) to be, in the absence of an applied field, perpendicular to the alignement layers. Nonetheless, the alignment layers are rubbed or otherwise conditioned, preferably in relatively perpendicular directions, and the gap is filled with a liquid crystal (38) having a negative dielectric anisotropy so that in the presence of a normally applied electric field the liquid crystals align perpendicularly to the applied field and are at their boundaries in parallel with the two perpendicularly aligned alignment layers, thereby forming a twisting structure within the cell gap. Thereby, in the absence of an applied voltage, light traverses the cell without effect upon its polarization. However, in the presence of an applied voltage (40), the light is waveguided by the liquid crystal having relatively displaced directors at the two alignment layers. Thereby, in the presence of perpendicularly aligned polarizers on the exteriors of the cell, the cell is dark in the absence of an applied voltage and becomes bright when a voltage is applied.</p> |
