Spatio‐temporal scanning backlight mode for field‐sequential‐color optically‐compensated‐bend liquid‐crystal display

Abstract— A spatially and temporally scanning backlight consisting of ten isolated micro‐structured light guides has been developed to be combined with a fast‐response optically‐compensated‐bend‐mode field‐sequential‐color LCD in which the liquid‐crystal cell does not contain color filters. The sequential fields of three primary colors are generated by illumination of the red‐, green‐, and blue‐light‐emitting diodes, each illuminating for one‐half of the field, resulting in a luminance of 200 cd/m² for the LCD. The effect of light leakage between the blocks in the scanning backlight in field‐sequential‐color applications was measured and will be described.     

Flexible LCDs fabricated with a slit coater: Not requiring an alignment film

A homogeneously aligned liquid crystal layer on a substrate film on which it is not necessary to form a liquid crystal alignment film can be assembled by a slit coater. Types of twisted nematic and in‐plane switching flexible liquid crystal displays were demonstrated. The production time can be considerably shortened because of the lack of need for an alignment film. The slit coater method is also applicable to the roll‐to‐roll process.     

High‐mobility solution‐processed organic thin‐film transistor array for active‐matrix color liquid‐crystal displays

Abstract— A solution‐processed organic thin‐film‐transistor array to drive a 5‐in.‐diagonal liquid‐crystal display has been fabricated, where semiconductor films, a gate dielectric film, and passivation films have all been formed using solution processes. A field‐effect mobility of 1.6 cm²/V‐sec, which is among the highest for solution‐processed organic thin‐film transistors ever reported, was obtained. This result is due to semiconductor material with large‐grain‐sized pentacene crystals formed from a solution and adoption of three‐layered passivation films that minimize the performance degradation of organic thin‐film transistors.     

Revised GMDH-type neural network algorithm self-selecting optimum neural network architecture

In this study, the revised group method of data handling (GMDH)-type neural network (NN) algorithm self-selecting the optimum neural network architecture is applied to the identification of a nonlinear system. In this algorithm, the optimum neural network architecture is automatically organized using two kinds of neuron architecture, such as the polynomial- and sigmoid function-type neurons. Many combinations of the input variables, in which the high order effects of the input variables are contained, are generated using the polynomial-type neurons, and useful combinations are selected using the prediction sum of squares (PSS) criterion. These calculations are iterated, and the multilayered architecture is organized. Furthermore, the structural parameters, such as the number of layers, the number of neurons in the hidden layers, and the useful input variables, are automatically selected in order to minimize the prediction error criterion defined as PSS.     

Resin micromachining by roller hot embossing

The roller hot embossing is an efficient process of manufacture in which patterns are continuously transcribed on film, etc. Recently, the application of the embossing roll to the manufacturing processes of micro parts is paid attention. In this paper, we examined the development of the embossing roll with patterns of micron level and we tried to make the embossing roll mold by using the LIGA process. In this study, instead of producing embossing patterns directly on the roll surface, we fabricated a flexible thin mold with micro-patterns, which was then wrapped onto a cylinder to form an embossing roll, and tested the soft-mold roller hot embossing method. First, by optimizing UV exposure conditions of UV lithography, we prepared a resist pattern of numerous dots with a diameter of 10 μm, a sag height of 8 μm and a pitch of 20 μm. By Ni-electroforming this pattern, a 50 μm-thick thin mold was successfully fabricated. The 50 μm-thick mold was then wrapped onto a cylinder to form an embossing roll. In the roller hot embossing process, the 10 μm-diameter dot shape was successfully replicated on PET sheets.     

Estimation of formation mechanism of spherical fine ZrO2-SiO2 particles by ultrasonic spray pyrolysis

Spherical fine ZrO₂-SiO₂ (11) particles were synthesized from a hydrolysed mix-solution of Si(OC₂H₅)₄ and ZrOCI₂ · 8H₂O by ultrasonic spray pyrolysis, and the formation mechanism of the particles discussed. All of the resultant particles identified as t-ZrO₂ and amorphous SiO₂ with an atomic order dispersion were spherical, and mainly of diameter 0.8 to 1.0m. It was estimated that the three-dimensional ladder siloxane chains containing an equimolar Zr⁴⁺ homogeneously dispersed were formed by hydrolysis, and an atomized droplet itself converted into an isolated ZrO₂-SiO₂ (11) particle without aggregation.     

Humidity-sensitive electrical properties and switching characteristics of BN films

This paper reports on the electrical properties of polycrystalline boron nitride (BN) films deposited on silicon substrates in a B₂H₆---NH₃---H₂ system. Virgin (unformed) samples exhibit humidity-sensitive electrical resistances. A current obeying Ohm's law at low humidities and low fields becomes space-charge-limited at high humidities and high fields. Some of the properties fundamental to their use as humidity sensors are also examined. After electroforming, BN films in the form of Ag/BN/Si/Al sandwiches begin to exhibit threshold switching only in atmospheres containing moisture. This switching behavior depends not only on the humidity but also on the sweep speed, the frequency of oscillation and the polarity of the applied sawtooth voltage pulse trains. A revised form Dearnaley's filamentary model is proposed.     

Pulsed NMR study of submonolayer and multilayer 3He films adsorbed on Grafoil

The nuclear spin relaxation times T ₁ and T ₂ of submonolayer and multilayer ³He films adsorbed on Grafoil have been measured at temperatures between 1.2 and 4.2 K by a pulsed NMR technique. The T ₁ data for high-coverage films (solid and dense fluid phases) and the substrate registered phase are interpreted in terms of thermally activated vacancies. In solids the quantum exchange inherent in ³He is shown to be important at low temperatures. The data for multilayer films are discussed in the light of the particle exchange between layers and the relaxation time of each layer. The dynamical behavior of adatoms in the solid, fluid, and substrate registered phases as well as the nature of phase transitions between them are discussed on the basis of information obtained from the analysis of T ₁ and T ₂ data. The present results as a whole seem to support the phase diagram determined by specific heat measurements. In addition, the nuclear susceptibility in submonolayer films has been measured by the same technique. The effect of Fermi degeneracy was not seen in the temperature range between 1.2 and 4.2 K.