A new bright single-panel LC-projection system without a mosaic color filter have been developed using a planar microlens array and a special configuration of dichroic mirrors. The dichroic mirrors, which is stacked in nonparallel arrangement, split a white light beam into three primary color (RGB) beams. Then three beems are projected upon single monochrome TFT-LCD from different incident angle respectively. Each microlens, which is associated with every three subpixels (RGB), distributes RGB beams just like a shadow mask of a color CRT. and converges RGB beams into corresponding subpixel apertures. The screen brightness of this newly developed system is improved more than three times compared with previously developed single panel LC-projector using a microlens array with a mosaic color filter.

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We are studying holographic display system using liquid crystal display. The influence of the defect in LCD panel on the holographic reconstructed images are experimentally studied. As a result, we found the tolerable maximum numbers of defect pixel in use for hologram was much more than in use for display.

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Generally, Frame response causes decreasing contrast ratio on fast responding STN-LCDs. We have evaluated three kinds of new driving methods that can solve this problem. At first we have measured contrast ratio of fast responding STN-LCDs under changing parameters on each driving method, and got conditions to minimize frame response. Then we studied configuration of these display systems, driving voltage, Power Consumption and display quality under those conditions.

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Driving techniques of antiferroelectric liquid crystals focused on phase transition from ferroelectric state to antiferroelectric state have been described. Electro-optic response under reverse pulse voltage depends on the viscosity and the products of pulse voltage and pulse width. Under low pulse voltage, anomalous behavior of mixed light through uniform, domain inversion regions and the mutual coupling is observed. New gray level control technique in which transmittance is controlled after writing to ferroelectric state is also investigated. The correlation between transmittance and electric charge, the technique to shorten the response time and the mechanism of gray level stabilization are clarified.

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In recent years, compact portable OA and AV equipments attract many interest, and accordingly bright and high resolution reflective LCDs without backlight are strongly required. As a reply to this requirement, we have proposed a reflective STNLCD with one polarizer and one retardation film. In this paper, the effect of the dispersion of birefringence of liquid crystal △n_<LC> (λ) and that of retardation film △n_R (λ) on the electro-optical properties of the STNLCD have been investigated, and the optimal combination of △n_<LC> (λ) and △n_R (λ) is clarified. In addition, the allowable deviations of cell-gap and the thickness of retardation film are clarified.

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Polymer dispersed liquid crystal (PDLC) cells with LC droplet type and polymer ball type morphologies are prepared using cyano end LC materials with different core parts and chlorine or fluorine end LC materials. In both type of PDLC cells, it was clarified that the end part of LC material bring on a change of morphology. A solubility of the LC in the polymer depends on each core part in the LC droplet type PDLC cells. Eelectro-optical properties, rise and decay times and memory effects of PDLC cells are also discussed in relation to LC properties.

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Liquid crystal displays (LCDs) have-been widely used, because of their advantages of low power consumption, compactness, and flatness. Above all, A/M LCDs, which supply excellent pictures, are expected to replace the conventional CRTs in near future. The controlling of pretilt angle of LC molecules in this A/M LCD is one of the most important technology to realize the large scale and fine pitch LCD. In this report, studies on the pretilt angles on the organic-solvent-soluble polyimides synthesized in our laboratory were reported.

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We present the results of the photo-alignment control of a nematic liquid crystal (NLC) by using poly vinyl cinnamate (PVC) films, which show a photopolymerizing process of 2+2 cycloaddition by exposing to UV light. We recogmize that the NLC is aligned homogeneously on the PVC films that are exposed by the linearly polarized UV light. We observe Characteristic disclinations in the photo-aligned LC cell when the NLC is injected into the cell in the isotropic phase. The creation of the disclination is proved to be due to the weak anchorage of LC molecules at an LC/PVC interface, and we achieve the reduction of the disclination density by using a high temperatur annealing method. This photo-alignment technique is applied to fabricate super-multidomain TN-LCDs, and successful results are obtained.

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