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We propose methods to obtain multi-domains with different threshold voltages for vertically aligned liquid crystal displays without additional transistors or capacitors. We exposed an ultraviolet light through a photomask and spatially varied the surface anchoring energy by partially decomposing the polyimide or inducing the adsorption of reactive monomers. The threshold voltage was reduced with smaller surface anchoring, and the reduction of the threshold could be qualitatively interpreted using a model describing a weak anchoring condition. [ABSTRACT FROM AUTHOR]

We propose a method for vertical alignment (VA) of liquid crystals (LCs) without alignment layers by mixing only a very low concentration (0.05 wt%) of an organic compound with LCs. The electro-optic characteristics of a VA cell fabricated by the proposed method were almost the same as those of a conventional VA cell with VA layers. Moreover, we used the proposed method to realise a polymer-stabilised VA device with a rapid response time without alignment layers. The proposed method can simplify the fabrication process and reduce the manufacturing cost of LC display devices by removing the need for alignment layers and the alignment process such as coating of polyimide layers and the UV exposure for the photo-alignment. We believe that the proposed method can play an essential role in the fabrication of plastic flexible LC display devices requiring the low-temperature process. [ABSTRACT FROM AUTHOR]

A transflective liquid crystal display using polymer-stabilised vertical alignment mode with fishbone-shaped electrode structure is proposed. Using the polymer stabilisation technique and patterned direction of pixel electrode structure, initial surface tilt angle and azimuthal angle can be well defined such that the liquid crystal is almost vertically aligned in the transmissive part while it has a certain pretilt angle that satisfies effective retardation of λ/4 with azimuthal direction of 45o with respect to the analyser in the reflective part. With optimisation of cell structures and surface tilt angles in the transmissive and reflective parts, a high performance transflective display showing excellent readability in any environment light conditions and single-gamma characteristic without using any retardation film or in-cell retarder can be achieved. [ABSTRACT FROM AUTHOR]

This paper reports surface treatment effect on liquid crystalline blue phase morphology and electro-optical performances at various temperatures. We have succeeded to achieve homogeneous monodomain blue phase morphology by surface treatment. Operating voltage and hysteresis of the proposed device is greatly reduced compared to the non surface treated cell, owing to dramatic increase in Kerr constant. Uniform mono domain morphology has better electric field withstand capability so that its original texture restored after electric field addressing. [ABSTRACT FROM AUTHOR]

- Three different blue-phase I liquid-crystal samples with different grain-size distribution were studied. Polycrystalline platelet grains reflects light in the visible region and have been observed under a polarizing optical microscope. Green and blue grain areas have been measured and then the statistical histogram by the Gaussian distribution function was fitted and the mean grain size was calculated. The effect of hysteresis on grain size has been compared for the three samples. Hysteresis depends explicitly on the grain-size distribution. Large grain size has revealed less hysteresis, while small grain size depicted pronounced hysteresis. [ABSTRACT FROM AUTHOR]

For the fabrication of protrusions in multi-domain vertical alignment liquid crystal displays (MVA-LCDs), a series of complicated and expensive photolithographic processes has to be gone through for the wide viewing angles. In this research, we proposed and demonstrated a new manufacturing approach of the protrusion utilising ink-jet printing technology. Parallel lines were ink-jet printed on the substrates and solidified by a subsequent baking process, and then used as the protrusions of MVA-LCDs. The geometric dimensions of the protrusion patterns were optimised by the comparison of experimental observations and computer simulation results. The MVA-LCD cell was fabricated by arranging the protrusion lines forming right angles between the top and the bottom lines, which resulted in cross-line protrusions. Due to the square-shaped geometric arrangement of the protrusions, the vertically aligned LCs formed the symmetric four-domains in the MVA-LCD cell. With the help of a surface polymer-stabilisation technique, the response time of the LC molecules under the electric field was significantly improved. Therefore, we can conclude that, without sacrificing the viewing angle and response time of MVA-LCD, the printing technique for the formation of the protrusions can give us a new fabrication opportunity with low cost in contrast to the conventional photolithography process. [ABSTRACT FROM PUBLISHER]

In this paper, we have reported a novel method for reducing hysteresis and operating voltage by stabilizing the disclination lines as well as double twist cylinders (DTCs). We have stabilized DTCs by incorporating photo reactive chiral monomer (SRM3) into the monomer mixed host blue phase liquid crystal (BPLC). Hysteresis and operating voltage of the proposed stabilized BPLC is reduced compared to the only disclination line stabilized BPLC. [ABSTRACT FROM AUTHOR]

A nano-material called POSS (Phenethyl-Poly Oligomeric Silsesquioxane) provides vertical alignment of LC on substrate without using conventional polymer type of vertical alignment layer. However, it still has many problems like aggregation because of high concentration doping. We synthesise new type of POSS which shows good dispersion with LC and found out that even very low 0.1 wt % into LC, uniform vertical alignment is achieved through diffusuion process from bulk LC to surface of the substrates. [ABSTRACT FROM AUTHOR]

Surface pinning effect of the optically isotropic, blue phase liquid crystal (BPLC) has been studied. Polycrystalline, platelet, multi-domain topological defects without surface treatment have been transformed to uniform monodomain in rubbed surfaces of the cell. The operating voltage was reduced by 27%, owing to a dramatic increase in the Kerr constant. Hysteresis was reduced by 63%, whereas the transmission efficiency gets doubled. The surface anchoring effect on the blue phase plays a significant role in the elastic free energy, coherence length and topological defects. BPLC displays with a low operating voltage, and reduced hysteresis can be realized with surface treatment. [ABSTRACT FROM AUTHOR]

We propose a pixel electrode structure for the multi-domain vertical alignment liquid crystal mode with high optical efficiency. We form a micro-slit electrode structure on the top substrate to reduce the width of disclination lines at domain boundaries. We insert additional electrodes on the bottom substrate to improve the transmittance at the edges of each pixel. We confirm that using both structures, the transmittance can be increased from 22.9% to 27.3% with no change in the operating voltage. [ABSTRACT FROM AUTHOR]