A novel active matrix display using newly developed monostable FLC is presented. FLC mixtures and alignment layers have been improved in order to obtain fast response times and a high contrast ratio of 100 : 1 at 25℃. Each gray level is almost constant in the range of viewing angle between -50 and 50 degrees without the reversal of images. Both rise and fall times below 200μs are regardless of the initial gray level. Moreover, the response times below 1 ms are achieved even at -5℃. A video-rate analog gray-scale display with the significantly wide viewing angles has been obtained by incorporating the monostable FLCs onto TFT active matrix devices.
A new LC panel structure which enables a really practical ferroelectric LCD is proposed by introducing a thermosetting epoxy"spacer". The new concept of the thermosetting epoxy spacer provides a honeycomb structure in the LC panel, resulting in a tenacious LC panel against mechanical shocks. Thanks to the tenacious panel structure, an FLC display is got rid of the vulnerability in a portable use.
Evaluation of voltage holding ratio of LC materials with negative dielectric anisotropy is performed. From the result, it was found that ion density and ion mobility is increased in materials which has poor voltage holding ratio property. Calculation of energy of dissociation was also performed on each materials with temperature dependency of ion density. From this calculation, it was assumed that different ionizable organic is existing in the each materials.
We have proposed a new brighter LCD backlight using highly scattering optical-transmission (HSOT) polymer. This polymer material consists of specified microscopic heterogeneous structures inside the polymer. The high-order scattering phenomenon in the HSOT polymer was exactly investigated by Monte Carlo simulation based on Mie scattering theory. We obtained a good agreement between the calculated and the experimental results. The scattering property inside the HSOT polymer can be optimized for the LCD backlight by using this simulation program. As the result, our back-light system consisting of the HSOT polymer plate has simpler system, brighter luminance, and better luminance profile. The property of our backlight system which was actually applied to the LCD is shown.
We have synthesized novel hole and electron transporting materials with a high glass transition temperature (Tg), based on the triphenylamine and the oxadiazole moieties, respectively, to improve the thermal stability of the organic electroluminescent (EL) device. For the hole transporting material, the Tg significantly increased by oligomerization of the triphenylamine ; the Tg of the pentamer was 145℃. The novel electron transporting materials were also found to have the high Tg above 120℃. Highly thermal stability has been achieved in the organic EL devices fabricated using such high Tg materials.
We found that the silole derivatives are useful as charge transporting and emissive materials for the organic EL devices. The silole derivatives with pyridine rings are the electron transporting material and those with thiophen rings are the bipolar charge carrier. The device with the dimer of phenyl derivatives shows high luminous efficiency.
To realize the next generation DVD having a 13〜15 Gbyte recording capacity, we studied mastering processes to extend a resolution limit of the Laser Beam Recorder (LBR) and devised a new mastering process. It uses photobleachable dye which is coated over the photoresist layer. Approximately 20% improvement resulted in a line recording density resolution in the case where the photobleachable dye, having large A parameter and small B parameter, is used together with a photoresist, whose sensitivity was adjusted to that of the photobleachable dye. By this process, a glass master was made having a 0.175 μm pit-length and a 0.4μm track-pitch. These figures show that this new technology can be applied to make a 15 Gbyte glass master still leaving some margin.
Nanometer-scale metal/Langmuir-Blodgett (LB) film/metal structure is realized with a scanning probe microscope (SPM). In this configuration, increase in conductance can be induced in the LB film by application of a voltage pulse. Atomic force microscopy combined with scanning tunneling microscopy (AFM/STM) shows that the conductance of the LB film changes without pit formation in the LB film or metal cluster deposition from the tip of the probe. The transition speed is faster than 1μs, and the transition can be induced at several thousand points, at least, without tip degradation. These facts demonstrate the feasibility of information storage devices with high density.
Systemic properties of ionic channels on the biological membrane were investigated by engineering linear system analysis. Calcium ionic channel on the biological membrane was expressed by four identical allosteric units which are voltage sensitive. Five open and closed states respectively, thus totally 10 states model were expressed by 10 linear state equations with conservation law. Linear system analysis disclosed that these mutual transitional states were stable but uncontrollable. There were six singular values which were relatively insensitive to frequency. The present linear system approach is useful to estimate an integrated properties of transient behaviors of the multiple states ionic channels.