| Thin Film Transistor Liquid Crystal Display (TFT‐LCD) is widely applied in TV, PC and mobile phone, etc.,for high‐quality display. It is very costly and wasteful to product TFT, and, becomes worse with the expansion of substrate size and production. it's essential to develop an alternative technology in industry of ebook,billboard needn't high refresh rate. Bistable technology gradually emerges with the enhancement of people's awareness of environmental protection and energy conservation. In terms of display technology, bistable state can own both bright and dark states in one display pixel without being charged. This display technology can save lots of electrical energy in application. In ideal circumstances, traditional LCD use up hundreds of times the electrical energy than bistable technology device. It is very suitable for application in screens needn't to be frequently updated, for example, commodity signs, e‐books, and, even large electronic billboards, etc,.The spectral characteristics and optical bistable characteristics of liquid crystal light valve (LCLV) driven by voltage were measured. The physical mechanism of nonlinear effect on the production of optical bistability are discussed, and the reason of LCLV's unconspicuous bistable state characteristics is analyzed. The results show that the twisted angle of liquid crystal light valve influence the optical bistable characteristics strongly, and the bistable state characteristics are found to be not obvious because the distortion angle of TN‐type liquid crystal light valve is only 90o. The optical bistable characteristic was found in a certain voltage range.The mechanism of the nonlinear effects of cholesteric liquid crystal in generating optical bistability and various factors in its display are analyzed. The optical bistability characteristics of the cholesteric liquid crystal drived by a pulse voltage were measured using an UV‐Vis 8500 double beam spectrophotometer. The spectrograms for different textured liquid crystals over a range in wavelength of visible light were obtainded. The results show that the energy of the focal cones pattern is lower than that of the planar pattern, moreover, with the increase of thickness of the liquid crystal, the transmittance and the contrast of various textured liquid crystal decreases. A reflective display device can be attained, if an absorption layer is added on the back side of the cholesteric liquid crystal bistable display device. As the thickness of the box increases, the reflectivity of the planar pattern enlarges, while that of the focal cones pattern almost keeps unchanged, thereby improve its display effect.A new type of liquid crystal grating, bistable liquid crystal grating,was designed in consideration of the optical properties of cholesteric liquid crystal. According to the bistable characteristic of cholesteric liquid crystal, this type of grating filled with cholesteric liquid crystal not only can work at zero‐field state by a series of surface treatment, but also can achieve tunable diffraction intensity under different pulse voltages. It is potentially applied in optical diffraction, optical switches and many other fields with simple production process, adjustable diffraction efficiency by electric field and polarizers saving.In addition to the applications in e‐books, billboards and mobile phones, bi‐stable can also be used in the currently popular flexible display technology with flexible substrate. With its intrinsic virtues of high contrast, wide viewing angle, etc., it will be one of the best choices in environmental protection display for electricity and pulp saving. |
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