Twisted nematic cell type LCD - has greater view angle in larger operating temp. range with less background noise

摘要

An LCD device has a TN cell (1) between polar filters. They (3, 4) are linear and are either parallel or crossed depending on whether positive or negative depiction is intended. Each filter (3, 4) has a degree of polarisation between 85 percent and 98.6 percent. The cell (1) has a nematic, twisted layer (2). The twist angle between the two layer surfaces is between 70 and 100 deg. Transparent electrode films are arranged on both sides of the liquid crystal layer (2) and a drive voltage is applied through which the optical transmission characteristics of the layer (2) are varied. The path difference d x deltan of the cell (1) is relatively small, preferably 0.4 to 0.6. USE/ADVANTAGE - Reflective, transmissive or transreflective devices, for positive or negative depiction. Increased angle of view with reduced amplification of background noise over larger operating temp. range. Better contrast. Reduced change in background noise with large temp. changes.