Liquid Crystal Light Valve Color Projection System
The trend of research and development of liquid crystal light valve color projection system is presented, firstly. Then, the two types of projection systems developed in our laboratory are given. One of the systems is based on a high-brightness, highresolution, electrically addressed, reflectively reading CR.T-LCLV spatial light modulators (SLMs). The other employs three transmitting-readout si-TFTLCLVs. The design features of the two types of the projection systems are demonstrated and the performance of the systems are given. applications. A variety of liquid crystal color projection systems [11--[51 have been produced. In this paper, we demonstrate the main design features of the two 111 color projection systems developed in our laboratory. Firstly, the color projection system is based on three electrically addressed, reflectively readout cathode-ray tube-liquid crystal light valve(CRT-LCLV) made in our laboratory. Secondly, the color projection system employs a long lifetime xenon arc lamp to photoactivate three highbrightness, high-resolution, transmissively readout liquid crystal light valves(LCLVs). The main design features and the performance characteristics are presented.
Full Color Projector With Single Liquid Crystal Light Valve
The projection system of the liquid crystal light valve (LCLV) coupled to Xenon arc source and high resolution CRT gives the advantage of high brightness and excellent resolution. The single light valve color projector concept lessens the cost at a slight sacrifice in resolution compared to a three light valve projector. The novel features and typical performance parameters for a new color graphics projector are: 1) use of miniature CRT's coupled to a single LCLV; 2) a color filter set to achieve color bands with minimum loss of light; 3) imaging and converging the color information by use of offset projection lenses; and 4) fine convergence of the information by digitally stored deflection correction signals. A prototype brassboard system was designed and constructed to evaluate the requirements for convergence, effect of the LCLV characteristics on uniformity of displayed hues, and the general performance parameters obtainable from a single LCLV color projector. Measurements to date shows modulated output of approx. 550 lumens (open gate of 800 lumens), limiting resolution for a primary color of 950 TVL, and contrast ratio of >50:1 for any of the colors. This paper describes the design and performance measurements in more detail.
An analytical approach to the design of electrodes in high-power, fast-transverse-flow CO2 lasers
Abstract Usually, the design of the electrodes of fast-transverse-flow CO 2 lasers relies more on experimental data than on theoretical analysis. Traditional systems sustain a stable, high-power discharge but the current distribution generates a peaked, non-uniform small-signal-gain pattern. We present a theoretical model suitable for the design of electrodes that achieves a quasi uniform gain distribution. The analysis, based on a two-temperature model and the gas-transport equations, computes the electron density that supports a flat gain pattern. Combining the desired electron density with the electron-balance equations, the model determines the required electric field. The results were used to design a new set of electrodes for a home-made fast transverse flow CO 2 laser. A stable, large volume discharge ( 4 × 8 × 90 cm 3 ) with very good uniformity was obtained. The resulting gain distribution was registered in a bi-dimensional map. The peak gain rose from 1.2 m - 1 , attained with the old electrode set, to 1.6 m - 1 with the new one and the gain showed a homogeneous profile.