Nematic liquid crystals and twisted-nematic LCDs

Since 1970, scientific and technological progress of the twisted-nematic liquid crystal display (TN-LCD) technology and subsequent polarisation-controlled field-effect LCDs strongly depended on the discovery, development and manufacturing of novel nematic liquid crystals. New experimental techniques had to be developed for determining all display-relevant LC-material parameters and correlating them with molecular structural elements and display performance. TN-LCDs with low operating voltage and power consumption, faster response, broader operating temperature range, multiplexability and, last but not least, long lifetime were some of the goals. Progress in LC-material R&D, device physics and display manufacturing broadened the range of TN-LCD applications from seven-segment, directly addressed displays in the early 1970s to increasingly more complex LCDs with higher information content. Examples include super-twisted nematic-LCDs in the 1980s and thin-film transistor-addressed TN-LCD monitors in the 1990s and beyond.