Liquid Crystal Displays with high brightness of visualization versus active displays

摘要

Nowadays Liquid Crystal Displays (LCD) takes the very important place among different visualization devices. It's are used in many standard applications such as computer or video screens. In May 2006, 100" LCD TV monitor had been shown by LG. But beside of this main direction of display development, very interesting - because of insignificant electro-magnetic disturbances - is the possibility of it's applications in motorization and aviation. An example of it can be a glass cockpit of U2 , Boeing 777 or many different car dashboards. On this field beside LCD we have now many another display technologies, but interesting for us are 3 of them: FEDs (Field Emission Displays), OLEDs (Organic Light Emitting Diode), PLEDs (Polymer Light Emitting Diode). The leading position of LCD is a result of LCD unique advantages of flat form, weight, power consumption, and reliability, higher (than CRT) luminance, luminance uniformity, sunlight readability, wide dimming range, fault tolerance and a large active display area with a small border. The basis of starting our investigation was the comparison of passive LCD and the other technology, which can be theoretically used on motorization and aviation field. The following parameters are compared: contrast ratio, luminance level, temperature stability, life-time, operating temperature range, color performance, and depth, viewing cone, technology maturity, availability and cost. In our work an analysis of Liquid Crystal Displays used in specific applications is done. The possibilities of the applications such a display under high lighting level are presented. The presented results of this analysis are obtained from computer program worked by authors, which makes it possible to calculate the optical parameters of transmissive and reflective LCD working in quasi-real conditions. The base assumption of this program are shown. This program calculate the transmission and reflection coefficient of a display taking into account the interference phenomena occurring into the display, different direction of ordinary and extraordinary wave vectors and its polarization vector, dispersion phenomena of refractive indices and absorption coefficient of the display layers.