In this study, we have proposed a new type of an optical depolarizer made from UV-curable liquid crystalline (LC) polymer. Local optical axes in a LC polymer film are randomly distributed by using an amorphous LC alignment structure. We theoretically and experimentally investigate depolarization characteristics of the proposed depolarizer, and the results are proved to be usefulness for an optical depolarizer.

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We achieved surface relief formation in the film of photo-cross-linkable polymer with alkenyl and benzophenone (BP) side group by holographic exposure to 325-nm He-Cd laser beams. Under holographic exposure, BP side groups induced photo-cross-linking of the film, which generated molecular motion, resulting in surface relief formation. The height of the surface relief depended on the composition and film thickness of the copolymer.

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To develop a novel photomobile material, films composed of crosslinked azobenzene liquid-crystalline (LC) polymer layers as photoactive layers and a polymer film as a substrate were prepared by atom transfer radical polymerization, followed a crosslinking reaction. Photoisomerizaiton of azobenzene mesogens and photomechanical properties of these compounds were investigated.

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The effect of doping gold nanoparticles on the refractive indices of liquid crystals was investigated. Gold Nanoparticle Doped Liquid Crystals (Au-NDLCs) were fabricated by sputter doping, and the absorbance spectra of the resultant samples showed a peak at 540 nm attributed to the localized surface plasmon resonance of gold nanoparticles. The refractive indices of pure-LCs and Au-NDLCs were evaluated by spectroscopic ellipsometry. The real part of refractive indices increased with a sputtering time due to the polarization of gold nanoparticles.

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The photo-cross-linkable hydrogen-bonded liquid crystalline copolymers (PLCs) contained cinnamic acid side groups and benzoic acid side groups were synthesized by radical copolymerization. The PLC revealed nematic LC characteristics due to hydrogen-bonded dimmer. Surface relief gratings (SRG) in PLC films were fabricated by using intensity modulated holographic exposing of 325nm He-Cd laser with various polarization. The fabricated SR gratings showed incident polarization dependency of the diffraction efficiencies, which indicates the molecular reorientaion in addition to the SR formation.

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Color tuning of FL derivatives with pyridine end groups was achiveded by doping in random and block copolymers containing carboxy acid side groups. The PL wavelength were gradually changed when doped in random copolymers , while changes were similar when doped in block copolymers.

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Laser amplifies light and generates an almost completely coherent light wave. Laser beam has excellent directivity and is a monochromatic light with extremely narrow spectrum width. Therefore, the strong interference (specle noise) occurs by the high coherence light and the surface topography of screen. In order to reduce the specle noise, we try to control the specle patterm by using liquid crystals which have electrically controllable optical characteristics such as optical phase defference, rotation of polarization plane, light. In this paper, we report the results of the specle noise reduction in utilization of FLC cells and/or wedge cells.

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We demonstrated polarization-independent refractive index modulation using cholesteric blue phase (BP) liquid crystal. BPs possess a three-dimensional periodic structure which is optically isotropic. Applying external electric field induces the distortion of the ChBP lattices, resulting in the polarization-independent refractive index modulation. As an example of device application and to confirm refractive index modulation, we fabricated an etalon containing ChBP liquid crystal. Upon applying electric field between 2 dielectric mirrors, transmission wavelengths were blue-shifted, and the transmission spectra did not change regardless of polarization states of the incident light.

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For a liquid-crystal (LC) lens, switching time of about 33 ms can be achieved by using a over-drive method. Recently, we have developed a low-driving-voltage type LC lens which needs only 3 Vrms in normal driving state. In this report, effects of the pulse voltage and the pulse width on switching properties of the low-driving-voltage type LC lens applying the over-drive method are studied. As a result, slope of the focus change is steep with the large pulse voltage and the switching time of 30 ms can be obtained. Clear images also can be observed in the transient state as well as images in the stable state.

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Liquid crystal microwave and millimeter wave phase shifter has been investigated by using the CPW substrate which is planar type of excellent circuit in the super high frequency region. However, there is a problem of reducing the effective LC permittivity change which controls the propagation of microwave and MMWs. In this work, a new device structure based on the microstrip line (MSL) is proposed, and fundamental characteristics of the device are investigated by FDTD analysis. Here, some investigation results are reported in detail about the influence of cell structural parameters to the propagation of MMWs, such as cell thickness, electrode width, substrate permittivity and etc.

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Recently, LCD monitors and TV's have grown a lot and mother glasses are getting larger. The application of Ink-jet technology has been expending to various new fields. PI inkjet system applies coating PI-fluid onto substrate surface as stream of droplets through minute nozzles, through pumping action utilizing expansion and contraction of selectively controllable piezo-electric devices, whereas in the conventional printing system, PI-layer is coated on the pattern-mask prepared for each pattern, then to be transferred onto substrate surface. The new method provides high-precision, high-speed, and reliable coating, and eliminates pattern-mask, cutting cost.

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Merck has been contributing for improvement of performance of AM-LCD with distinguished LC materials from the beginning stage. We would like to continue our LC mixture development not only for conventional LC modes, TN, IPS and VA, but also advanced technologies, PS-VA and blue phase, for realization of high performance LCDs.

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We developed a low-haze VA compensation TAC film for high contrast ratio VA-LCDs, by reducing micro anisotropic nonuniform structure inside the stretched TAC film. Moreover, we found that the arrangement of the compensation film as a single compensator on the front side of VA-LCDs with color filter on TFT arrays realizes more than 10 % higher on-axis contrast ratio than that of conventional compensation films as double compensation films.

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To improve quality of images of liquid crystal displays (LCDs) such as their viewing angle performance and coloration, we have developed liquid crystalline retardation film technology by using rod-like liquid crystalline polymer. Comparing with the conventional stretched retardation film, the liquid crystalline film has advantages in its unique orientation form and small thickness. Well-controlled structures such as twisted nematic, hybrid nematic and homeotropic structure enable ideal compensation of STN, TN, ECB, VA and IPS LCDs.

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Developments of thinner LED backlights for mobile display are described. The thickness of the backlight depends on the number of prism sheets and the slope height between LED and the illumination area of the light guide. In order to eliminate the prism sheets, Vector Radiation Coupling method was proposed, in which the light emitted from the light guide is condensed toward the upward direction without any prism sheets.

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TFT-LCD panels have been widely used for LCD-TV and high-end information display devices. However, there are sudden defects such as image sticking in TFT-LCD panels, so that we have made the equipment to measure mobile ions in TFT-LCD panels and obtained helpful data for an analysis of image sticking phenomena. In this paper, I propose how to avoid the influence of image sticking in TFT-LCD panels.

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Large quantities of obsolete electronic devices are currently being generated. Concerning metal recycling process of Liquid Crystal Display(LCD) , the following topics were introduced . New process to recycle indium from indium tin oxide (ITO) in the transparent conducive film used in LCD panels was developed. Recovery of Indium is achieved to 93-98% with very easy process. LCD devices are known to contain some potentially toxic or hazardous constituents. Proper classification for risk control is important in recycling of end-of-life(EOL) LCDs. Some of rare metals are produced by DOWA-group (Cupper,Lead,Zinc smelters and refineries) .

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