| 20110249226 | SELF-COMPENSATING, QUASI-HOMEOTROPIC LIQUID CRYSTAL DEVICE WITH HIGH CONTRAST RATIO - Self-compensating, quasi-homeotropic liquid crystal devices overcome the contrast reducing effects of smaller pretilt angles. The devices exhibit extremely high contrast ratio but at the same time suppress fringe field-induced disclination lines in high pixel density and small pixel size quasi-homeotropic displays. The surface pretilt and cell twist angles are set at values that, in combination, contribute to establishing a cuspate singularity in the contrast ratio for normally incident light in response to a drive signal switching the liquid crystal device to the OFF director field state that provides nearly 0% optical efficiency. The OFF director field state corresponds to a subthreshold drive level that provides for the liquid crystal device self-compensation for in-plane optical retardation. Setting the cell gap (“d”) to provide substantially 100% optical efficiency in response to a value of the drive signal switching the liquid crystal device to the ON director field state achieves optimal dynamic range for the liquid crystal device. | 10-13-2011 |
