This paper reviews the development of low temperature poly Si TFT, scattering light valves addressed by TFTs and a brighter video projection system using them, with the attensin of their optical aspects. The first includes main feature which are laser induced crystallization of PECVD a-Si in almost entirely solid phase by high speed scanning CW Ar laser beam. The second includes photo-polymerization induced phase separation method for the preparation of liquid crystal polymer composite (LCPC) material and scattering light valve with low driving voltage of 6 Vrms. The last gives a brighter video screen image with high contrast ratio and includes higher light efficiency through LCPC light valves and projection lens unit by about four times than that of conventional LC light valves with polarizers.

Existing solid models often contain redundant primitives and null blocks, which both slows down the rendering process and makes the process complex. There has been recent progress toward solving this problem, but existing modeling schemes cannot support eliminating all the redundancies, especially the null blocks, from the solid models. This paper proposed a technique that can eliminate redundancies. By dividing a primitive into some surface dispersed points, a new primitive representation is obtained. The sample segments of the primitive or the object are used to locate composition position to prevent the null primitives from being generated. By drawing out the geometric shape points set corresponding to a common acting area, the volume boundary of a primitive or an object is evaluated by only the Boolean set operations. The null blocks can be picked out in terms of the volume boundary. The resulting solid model generated in this way has no redundancies and is suitable for fast rendering of the image.

A new set of self-consistent linear equations is presented for the analysis of the startup characteristics of gyrotron oscillators with an open cavity consisting of weakly irregular waveguides. Numerical results on frequency detuning and oscillation starting current for a whispering-gallery-mode gyrotron are described in which these equations were utilized. Experiments for making a check on the effectiveness of the derived equations showed that they well express the operation of gyrotrons in comparison with the linear theory using an empty cavity field as the wave field.

A yellow light emitting display using neon-hydrogen-argon mixture as filling gas is presented. Strong "monochromatisation" of the emitted light is reported for the first time on the wavelength λ585.3 nm. Experimental results on the dependence of the "monochromatisation effect" is given for various pressure values and filling gas composition. It is underlined the existence of a process of selective population of the upper level 3p[1/2]0 of the transition corressponding to the wavelength 585.3 nm. The obtained results are discussed in relation with the reported results on yellow light laser in which a discharge in neon-hydrogen mixture is used for laser radiation generation at λ585.3 nm. The proposed explanation of different authors on the upper level population through radiative or dissociative recombination of neon ions is discussed and a new hypothesis is advanced for the strong monochromatisation observed in neon-hydrogen or neon-hydrogen-argon filled displays. According to this hypothesis, in the feeding process of the upper level 3p[1/2]0 are taking part the neon metastable states too. If such an assumption will come true, cyclic processes in yellow light generation might appear.

Transmittance distribution along a horizontal line in LCDs addressed by amorphous silicon TFTs was investigated using measurements and calculations. Nonuniformity of the distribution, in which the transmittance increased with increasing distance from the left edge of the LCD, was observed in a 10 inch diagonal TFT-LCD. The cause of the nonuniformity was attributed to the decrease in voltage drop due to the gate source parasitic capacitance and the increase in gate voltage fall time due to large line resistance, based on the measurements of voltage drops in TFT test elements and calculations considering the decrease in voltage drop. The distribution could be improved by reducing the line resistance and parasitic capacitance in the actual LCD.