TFT‐addressed full‐color reflective‐type display using mixed‐mode twisted‐nematic LCD

Abstract

Abstract— A high‐performance reflective‐type TFT‐LCD with full‐color and video‐rate capabilities has been developed. This display utilizes a single‐polarizer geometry associated with a mixed‐mode twisted‐nematic (MTN) effect. The twist angle of the liquid‐crystal cell is optimized by evaluating the light efficiency, contrast ratio, chromaticity, and gray‐shading reproducibility with respect to the variation of cell‐gap uniformity. Attractive features of this display such as low driving voltage, fast response, wide viewing angle, rich gray scales with superior color reproducibility, and clear image with no parallax are demonstrated.

P‐84: Optimization of Reflective Liquid Crystal Display with a Holographic Slanted Reflector Using the Berreman 4×4 Method

“…Figure 3. When this plot is compared with previous published data [4], it is found that LCDs which have twists of 70°, 80°, and 90° and ∆nd values of 0.275, 0.26, and 0.24 µm, respectively, have decreasing brightness which is seen above, marked by dots. LCD is not nearly as good as that of the 70°, 80°, or 90°, therefore the 100° twist cell is not normally used for displays.…”

“…Enlarged region of interest for the reflectance contour plot fromFigure 5. When this plot is compared with previous published data[4], it is found that LC cells which have twists of 70°, 80°, and 90° and ∆nd values of 0.275, 0.26, and 0.24 µm, respectively, have decreasing darkness which is seen above, marked by dots.…”

“…This situation is fundamentally different from crossed or parallel polarizers because after the light goes through the polarizer and quarterwave plate it reaches the LC as circularly not linearly polarized light. This situation was not analyzed by Kwok but was reviewed by Kuo [4]. We compare our simulated data below with Kuo's even though the two sets of data were calculated using different LCs.…”