We have studied the electro-optical properties in Polymer Network Liquid Crystal Displays which are composed of a three-dimensional polymer network formed in continuous liquid crystal layers prepared by photo-polymerization induced phase separation processes. In view of the behavior in the orientation of the liquid crystal molecule at the polymers surface, it can be clarified that the electro-optical properties are strongly governed by the polymer. By a combination of two different characteristics of the polymers with respect to a temperature dependence, a variation in the driving voltage for a temperature change can be improved.

A homeotropic liquid crystal display utilizing a liquid crystal with positive dielectric anisotropy, 13. 3" XGA TFT-LCD, has been fabricated. The rubbing-free device, appears black in the absence of electric field. When an electric field generated by interdigital electrodes is applied, a bend deformation of molecular director to the direction of the field occurs and thus the cell transmits light, showing brightness uniformity in all directions owing to the dual domainlike director configuration. With an addition of negative-birefringent film, this device shows excellent viewing angle characteristics.

A method to improve the reflection efficiency of holographic polymer dispersed liquid crystal (HPDLC) is proposed and its effectiveness is confirmed. Controlling the alignment of liquid crystal (LC) in tiny droplets of HPDLC can increase the refractive-index difference between the LC droplet layer and the polymer layer, causing the peak reflectance and reflective spectral width to expand. We observed experimentally that 96% of the light components excluding the scattering loss can be diffracted in a transmission HPDLC device by ordering the LC. In a reflection HPDLC, we found that reflection could be improved by ordering through an applied shear force. Our findings should lead to an improvement in the quality of reflective display devices.

We have analyzed a displayed image of TFT-LCD three-dimensionally in case of low power drive using Multi-Field Driving Method (MFD). We have also proposed a concept of multi-media driving method using MFD in which a displayed image was divided into some interlaced subfield images and the number of interlaced subfields can be changed depending on the moving quantities of displayed images. This method made it possible not only to reduce a driving power consumption in case of still images to less than half, compared to that with conventional methods, but also to maintain high moving image quality.

We have proposed a highly scattering optical transmission (HSOT) polymer for use as a high efficiency light source medium. This polymer contains specified internal microscopic heterogeneous structures for controlling light-transmission properties. An LCD backlighting system having a new light pipe made of this polymer has twice the brightness of the conventional one. A light scattering phenomenon inside the HSOT polymer was quantitatively analyzed by a ray tracing simulation based on the Mie scattering theory and the Monte Carlo method. The illumination of the backlight which is optimized by using the simulation program has enough uniformity of intensity and color because of specified multiple light scattering phenomena inside the HSOT polymer. We propose the new backlighting system having fewer components and twice efficiency of the conventional one.

Differences in the behavior of dispenser cathodes and oxide cathodes in laminar-flow type and crossover type electron guns were investigated by experiments and simulations under high-current-density conditions. When an oxide cathode is operated under such conditions, the heating effect due to Joule heat in the oxide layer exceeds the cooling effect, depending on the product of the work function and the cathode current, resulting in a rise in the cathode temperature. This rise in cathode temperature aggravates deterioration of emission characteristics during the life of an oxide cathode. In the case of the dispenser cathode, however, the cathode temperature decreases under high-current-density conditions. When an oxide cathode in a crossover type electron gun is operated, equipotential surfaces are formed in the curved surface in the oxide layer. The formation of an equipotential surface leads to relaxation of the loading. It is considered that this is the reason for the longer life of an oxide cathode in a crossover type electron gun than that of an oxide cathode in a laminar-flow type electron gun.

To improve the resolution of the color CRTs, we propose a new electrostatic lens system which has two additional electrodes between the focus electrode and the anode electrode. The anode voltage and focus voltage are supplied on these additional electrodes. The numerical simulation shows that the system can reduce the third order aberration coefficients almost up to 31% of the conventional system. And the experiments show that the typical beam spot diameter is improved by nearly 20% of the conventional system.

Ion beam irradiation effects on a novolac positive-tone photoresist and its application to micron-size field emitters have been investigated. Irradiation of Ar and P ions was examined. The electrical resistivity of the photoresist film is found to decrease after Ar ion implantation at doses on the order of 10¹⁶ cm^-2. Baking of the photoresist prior to irradiation at a high temperature is preferred to produce electrical conductivity. P ions show weaker effects than Ar ions. Raman spectroscopy shows that carbon-carbon bonds such as the graphite bond are produced due to ion bombardment. The field emission of electrons is observed from emitters made of the ion-irradiated photoresist. The emission current is shown to be fairly stable when it is compared with an emission characteristic of synthesized diamond. Fabrication of field emitter arrays using a mold technique is demonstrated. The field emitter array shows emission at a current level of about 40 µA.

Gd₂O₂S:Tb phosphor thin films have been prepared using the simple technique of electron beam evaporation for large area display applications. The photoluminescence and excitation spectra measurement of Gd₂O₂S:Tb phosphor thin films suggest that Tb³⁺ is incorporated into the Gd₂O₂S lattice at gadolinium sites. Relatively efficient electroluminescence is observed from a ZnS/Gd₂O₂S:Tb/ZnS sandwich cell.

A 14. 4-in. diagonal EL display with 640128 pixels has been developed in red/green multicolor structures by using a new phosphor layer consisting of Zn_1-xMg_xS:Mn and ZnS:Mn. The display is designed for 240 Hz-frame rate, enabling the luminance to be improved by a factor of two. In addition, the contrast ratio is strongly enhanced by optimizing the black background structure and color filters. Improved characteristics make it possible for the EL panel to meet the requirements for the public information display taking advantages of high-reliability, crisp image and wide-viewing angle. Furthermore, the possibility of full-color EL displays will be described on the basis of "color by white" approach.

The performance of AC plasma displays has been improved in the area of brightness and contrast, while significant advances in image quality are still required for the HDTV quality. In particular, in full color motion video, motion artifacts and lack of color depth are still visible in some situations. These motional artifacts are mitigated as the number of the subfields increases, usually at the cost of losing brightness or increasing driving circuitry. Therefore, it is still one of our great concerns to find out the optimized subfield configuration through weighting and order of each subfield, and their coding of combination. For evaluation and improvement of motion picture disturbance, we have established a procedure that fully simulates the image quality of displays which utilize the subfield driving scheme. The simulation features virtually located sensor pixels on human retina, eye-tracking sensor windows, and a built-in spatial low pass filter. The model pixelizes the observers retina like a sensor chip in a CCD camera. An eye-tracking sensor window is assigned to every light emission from the display, to calculate the emissions from one to four adjoining pixels along the trajectory of motion. Through this model, a scene from original motion picture without disturbance is transformed into the still image with simulated disturbance. The integration of the light emission from adjoining pixels through the window, also functions as a built-in spatial low pass filter to secure the robust output, considering the MTF of the human eye. Both simulation and actual 42-in-diagonal PDPs showed close results under various conditions, showing that the model is simple, but reasonable. Through the simulation, general properties of the subfield driving scheme for gray scale have been elucidated. For example, a PWM-like coding offers a better performance than an MSB-split coding in many cases. The simulation also exemplifies the motion picture disturbance as a non-linear filter process caused by the dislocation of bit weightings, suggesting that tradeoffs between disturbance and resolution in motion area are mandatory.

In this paper, a novel pass-transistor logic with an efficient level restoration circuit, named Power Saved Pass-transistor Logic (PSPL), is proposed. It is shown how, through the use of regenerative feedback with pMOS switches, we reduce the power consumption and propagation delay compared to conventional pass-transistor logic. To demonstrate the performance of PSPL, a 5454-bit multiplier is designed. For speed and power optimization, the multiplier uses high compression-rate compressors without Booth Encoding, and a 108-bit conditional sum adder with separated carry generation block. The measured multiplication time was 13. 5 ns in a 0. 6 µm single-poly triple-metal 3. 3 V CMOS process. Furthermore, a sequential circuit of a low power 7-bit serial counter is designed and fabricated in a 0. 6 µm single-poly triple-metal 3. 3 V CMOS process. The measured operating speed was 250 MHz.

Cursor RAMs have been composed of two memory planes. A cursor pattern is stored in these planes with 2-bit data depth. While the pixel port requires data from both planes at the same time, the MPU port accesses either one of the planes at a time. Since the address space is defined differently between the ports, conventional cursor RAMs could not have dealt with these different access ways at real time. This paper proposes a dual port cursor RAM with a dynamic data alignment architecture. The architecture processes the different access ways at real time, and reduces a large amount of control circuitry. Conventional cursor RAMs have been organized with a single port memory because dual port memory cells have been large. We have applied the port swap architecture which has reduced the cell size. The control block is further simplified because the controller no longer emulate a dual port memory. The cursor RAM with these architectures is fabricated with a double metal 0. 5 µm CMOS process technology. The active area is 1. 51. 6 mm² including a couple of shift registers and a control block. It operates up to 263 MHz at the supply voltage of 3. 3 V.

A unified theory for the characteristics of dual modes in a circular resonator is elucidated in simple analytical expressions. First, a circular resonator is considered as a ring transmission line which allows two oppositely traveling waves. The essential quantities that characterize a transmission line, i. e. , the propagation constant and characteristic impedance are obtained theoretically and/or experimentally. Secondly, any circular resonator is described by a ring resonator model which can be treated analytically, and the resonant frequencies are obtained when perturbations are added along the periphery of a circular resonator. A two stage BPF is created by adding I/O ports to the perturbed circular resonator. Its center frequency and bandwidth is calculated based on the ring resonator model. The circuit condition for obtaining two attenuation poles at both sides of the passband is given together with the method for their control.

In order to enhance the energy transfer efficiency in a Cherenkov laser, we propose to use a tapered waveguide with a dielectric thickness properly varied stepwise in the longitudinal direction. With the aid of particle simulation, we investigate the nonlinear characteristics of the Cherenkov laser with the tapered waveguide, demonstrating the effectiveness of our proposal for efficiency enhancement.