The present status of liquid-crystal material development for the low driving voltage AM-LCD and the high definition AM-LCD is presented. Influence of fluorination on physical properties of liquid-crystal substances is presented and an approach to find effective fluorinated substances to lower the threshold voltage is given. These substances enable us to develop a mixture having very low threshold voltage, which can be addressed by 3V-drivers.

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We have synthesized new polymeric ferroelectric liquid crystals (PFLCs) with an alkanoyl group. The feature of these PFLCs is large spontaneous polarization (Ps), which leads to a high switching speed. The highest Ps of over 500 nC/cm^2 was attained with the PFLC with two chiral groups. Copolymers and mixtures containing these mesogenic components were also prepared in order to optimize the switching and thermal properties. In preparing these composites, the alignment of liquid crystal molecules was a determining factor for improving the properties. A liquid crystal film cell using the polymeric liquid crystal composite was fabricated, and this thin and light-weight cell was found to be mechanically stable.

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The semi-empiribal AM1-MNDO-molecular orital calculation have been applied to investigation of the dielectric anisotropy (Δε) of liquid crystal compounds. At first, dipole moment (μ) and anisotropy of polarizability (Δα) are calculated by molecular orital calculation. Then, Δε is obtained by substituted the μ and Δαin the Maeir-Meaier eqution. The method is applicable to many liquid crystal compounds with various polarized groups and skeltons. The results are in close agreement with experimental data.

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The influence of the constituent elements of Liquid Crystal Display and Liquid Crystal mixtures on the performance of Liquid Crystal Display is examined. Especially the congeniality between Liquid Crystal mixtures and the sealant is examined. The current and holding ratio is changed by the kind of ions and liquid crystals, and the dielectric constant of liquid crystal. Fluoride components used in AM-LCD are tolerant of ion.

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Color filters (CFs) for liquid crystal displays (LCDs) are divided into two types dye and pigment. Recently, the pigment type has been expanding rapidly, due to its higher stability. Several CF manufacturing methods are established, and CFs productivity is dramatically increasing. Important future issues are cost reduction, larger size improvement and higher resolution. LCD manufacturers also strongly demand CFs with higher contrast and lower reflection Black Matrix. In addition to these improvements, the coating and inspection systems are also being reviewed.

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Organic thin film EL devices have been extensively investigated in recent year. We synthesized N, N'-diphenyl-N, N'-(3-methyl phenyl) 1,1'biphenyl-4,4'-diamine (TPD) and two diamine derivatives synthesized in the same way, and exmined these thermal stabilities by measuring these glass transition temperature(Tg). We fabricated thin film double-layer structure utilizing these diamine derivatives as a hole transport layer and measured luminescent properteis and deterioration characte ristics of these devices.

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Polymer stabilized liquid crystal cells using a mixture of a nematic liquid crystal (NLC) and photocurable liquid crystalline monomer have been successfully fabricated. The conformation of the photo-cured polymer network is determined by applying external orientation forces (electric or magnetic field) in the monomer state and successive photo-curing. The resulting conformation of a NLC media is determined through the interaction with the formed network. We study on the LC molecular alignment effect by means of the observation of the Nematic-Isotropic phase transition behavior. From the results, we find that the behavior of the phase transition is different comparing with a conventional system without a polymer network. Furthermore, it is clarified that the interaction between a polymer network and LC molecules is strong.

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A TN-LCD that features a wide and homogeneous viewing angle characteristics and an excellent grayscale capability with a high legibility has been fabricated and demonstrated by dividing a pixel into four subpixels(quartered subpixels ; QSP). LC alignment method is achieved by using polarized UV light irradiated photopolymer polyvinyl cinnamate (PVCi) films. A mechanism of LC alignment by using PVCi is clarified and a good unidirectional LC alignment accomparying pretilt angle is attained by adopting a special photo-irradiation method that features an appropriate combination of double exposure and slanted irradiation. As a result we succeeded in fabricating reverse tilt disclination free mono-domain TN-LCD and also in demonstrating a matrix TN-LCD having QSP in which the position and shape of reverse tilt disclinations are completely controlled.

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A polarizer free reflective spiral polymer aligned nematic (SPAN) guest host LCD exhibiting low operation voltage, a high luminance, a good contrast ratio, and good viewing angle characteristics has been fabricated by photo-polymerization of a chiral acrylate monomer in a nematic liquid crystalline host including a black dichroic dye.

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