ABSTRACT
The outdoor readability of the most popular portable liquid crystal display (LCDs) viz. fringe field switching has been addressed both in single and dual cell gap transflective devices. The devices use dual orientation, such as, homogeneous alignment in transmissive (T) part and 64° twisted alignment in reflective (R) part. The dark states of the proposed devices are achieved by controlling phase retardation in T part and polarization rotation in R part and the white state is realized by rotating optic axis of liquid crystal and removing phase retardation in T and R parts, respectively. The devices show high light efficiency without requiring any optical compensation films, exhibiting strong potential for portable display applications.
Subject(s)
Data Display , Liquid Crystals/chemistry , Refractometry/instrumentation , Electromagnetic Fields , Equipment Design , Equipment Failure Analysis , Liquid Crystals/radiation effectsABSTRACT
Conventional transflective liquid crystal displays (LCDs) with single cell-gap requires optical compensation films or patterned retarders to balance the optical path-length difference between transmissive and reflective regions. In this paper, novel single cell-gap transflective LCDs driven by fringe electric field without using the compensation film or in-cell retarder have been proposed. The liquid crystal director is aligned parallel to analyzer but makes an angle of 45° with respect to analyzer in reflective region. In addition, the surface pretilt angle in the reflective region is controlled by vertical field and polymerization of an UV curable reactive mesogen at the same time and thus, the effective cell retardation in the reflective region becomes smaller than that in transmissive region. Consequently, without using any compensation film or in-cell retarder, the single cell-gap and single-gamma transflective LCD with high performance is realized.
