In-plane switching of a twisted-nematic liquid crystal cell for single-cellgap transflective display

We propose an optical configuration of a twisted-nematic liquid crystal (TNLC) device driven by an in-plane electric field for a single-cellgap transflective display. The dark state of the reflective part is realized by a nematic liquid crystal layer with the twisted angle of 63.6° and the retardation of 194 nm, while a quarter-wave plate is inserted for the dark state of the transmissive part. Wavelength dispersion of the TNLC layer is suppressed by introducing a half-wave plate, whose optimum angle is found by using the Muller matrix method. Different directions of electric fields rotate liquid crystals to 15° for the bright state of the reflective part, but to -30° for that of the transmissive part. With the proposed configuration, we can realize a single-gamma transflective display in single cellgap structure without any in-cell retardation layers. By fabricating a 2.0" qCIF+ (176×RGB×220) prototype panel, we demonstrated both high reflection/transmission and single gamma of the proposed configuration.