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We propose a novel method to fabricate a uniaxially homogeneous alignment of liquid crystal (LC) molecules without using a conventional alignment layer such as polyimide film. The method produces the polymer alignment layer (PAL) by polymerisation of the monomer including in the LC layer above the TNI of the LC material. The fringe-field switching (FFS) mode LC cell with the PAL (FFS-PAL-LC cell) produced from the monomer 4,4ʹ-di-mehacryloyl-oxy chalcone (4,4ʹ-DMOCh) exhibited enough level of alignment state and electro-optical property compared with the FFS-LC cell having the conventional polyimide-type alignment layer. We can expect that the FFS-PAL-LC cell is useful for next-generation displays such as flexible liquid crystal displays (LCDs) because the method does not need high-temperature process of over 200°C.

We have developed a novel bright reflective color display, which combines the polymer network liquid crystal (PNLC) containing dichroic fluorescent dyes and the ultra-low-power driving technology. The high reflectance, 60% at the maximum, was achieved by enhancement of the external light emission from the dyes due to the light-scattering effect of PNLC.

A novel reflective color LCD without polarizer has been developed with using PDLC and retro-reflector. Bright color images including moving images are available with utilizing ambient light. Our novel LCD will create a new application area such as electronic paper.

We have investigated the dynamics of the process of annihilation of a wedge disclination pair generated in a nematic cell with hybrid alignment, by quenching it from its isotropic phase. The time evolution of the separation between the defect pair can be classified into two stages: the early stage, with a stringlike pattern of schlieren texture immediately after a defect pair is generated; and the late stage, with a round pattern before the defect pair is annihilated. The experimental results show that the separation between the defect pair decreases linearly with time in the early stage, and then diminishes to zero in proportion to the square root of the time to coalesce the defect pair in the late stage; these are easily explained with a two-dimensional phenomenological model by including an additional field with an ordering effect. By numerical simulation, we have also studied the annihilation dynamics of a three-dimensional equation of motion based on the Frank elastic energy without a phenomenological ordering field. The simulation results are in good agreement with the experimental ones, which indicates that the defect pair behavior in the early stage is attributed to the hybrid alignment, with a coupling energy between the tilt angle and the azimuthal angle. From a comparison between the phenomenological model with the ordering field and the numerical simulation, we can clarify the molecular origin of the ordering field, which has been introduced to explain the unusual annihilation process in the early stage.

We investigated the dynamics of annihilation process of a defect pair in the nematic phase which were generated as type-1 wedge disclinations by quenching the isotropic phase. We measured the time dependence of the distance between a defect pair with or without external electric field. The distance decreased linearly with time immediately after the defect pair was generated (the early stage) and then decreased to zero in proportion to the square root of the time to elapse before the defect pair was annihilated (the late stage). We also treated the annihilation dynamics by numerical simulation with a two-dimensional phenomenological equation of motion, and the simulation results were in good agreement with the experimental ones. The ratio of the coefficient of viscosity to that of elasticity and the strength of ordering field were evaluated from the comparison between the simulation and experimental results.

Ogi H., Hirao M., Minoura K. "Noncontact measurement of ultrasonic attenuation during rotating fatigue test of steel", Journal of Applied Physics, 81(8), 3677-3684 (1997) https://doi.org/10.1063/1.365489., Acoustic resonance technique has been applied to monitor the fatigue damage process of steel pipes exposed to rotating bending fatigue. The technique incorporates a superheterodyne spectrometer and an electromagnetic acoustic transducer (EMAT). The EMAT was newly developed for this purpose, and uses the magnetostrictive mechanism of ferromagnetic metals and excites and detects axial shear waves traveling around the sample pipe with axial polarization. Noncontact ultrasonic spectroscopy permits the accurate determination of the resonant frequency and the attenuation coefficient throughout the fatigue life. The attenuation coefficient shows a sharp peak around 80-90% of the life. The evolution is interpreted as reflecting dislocation multiplication, depinning, and formation of cell structures, which is supported by transmission electron microscopy observations. © 1997 American Institute of Physics.

For the first time, we have developed a 60-inch diagonal size see- through display using polymer network liquid crystal (PNLC) technology. The color display system by combination of the see- through display and a projector enables distinguishing eye-catch effect. It creates new application of displays, such as information display, digital signage and substitution of window.

We have developed an over 60-inch size Moth-eye anti-reflection surface, which has original shaped nanostructures. The minimum reflectance was 0.02% and the average was less than 0.04% with little wavelength dependence. Moreover an anti-glare function was added. The 60-inch LCD applied AG Moth-eye surface had an excellent visibility in bright environments.

It is possible to control the alignment of columnar liquid crystalline π-conjugated systems by controlling photoluminescence (PL) properties to yield a polarized PL effect by shear stress. A polarization ratio of 11.2 at the fluorescence peak was obtained using columnar liquid crystalline π-conjugated oligothiophenes [T. Yasuda et al., Adv. Funct. Mater. 19, 411 (2009)]. We have therefore revealed the directional distribution of oligothiophene molecules inside the columns, which is the origin of a highly polarized PL emission, through detailed analysis of the dependence of PL polarization ratio on the detection polar angle, assuming that such PL emission is due to the summation of all dipole radiations from oligothiophene molecules in the measured area of the sample.

We have developed a novel reflective LCD without polarizers, which is sure to provide excellent visibility (reflectance = 50%, CR = 10:1). Moreover, we have also achieved extremely low power consumption of 10 microwatts to introduce low frequency driving (less than 1Hz) without flicker and image sticking. These characteristics were realized to combine pixel memory circuit and new PNLC material.

— A novel reflective color LCD without polarizers has been developed using a PDLC film and a retro-reflector. Bright color images including moving images are achievable with ambient light. This novel LCD will enable the new application area of electronic paper.

Novel reflective color LCDs without polarizers have been developed with using PDLCs and retro-reflectors. By eliminating polarizers, brightness of our newly developed LCDs has been increased by 51% compared to conventional reflective LCDs, and there still is much room to be improved. What's more, our LCDs can be displayed not only bright text images but also color moving images on, since their response time and driving voltage are significantly fast (63ms) and low (5.5 volts).