A single-cell-gap transflective liquid-crystal display using different pretilt angles in transmissive and reflective regions

A single-cell-gap transflective liquid-crystal display with two types of liquid-crystal alignment based on an in-plane-switching structure is proposed. The transmissive region is almost homeotropically aligned with the rubbed surfaces at parallel directions while the reflective region has a homeotropic liquid-crystal alignment. For every driving voltage for a positive-dielectric- anisotropy nematic liquid crystal, the effective cell-retardation value in the transmissive region becomes larger than that in the reflective region because of optical compensation film which is generated by lowpretilt-angle liquid crystal in the transmissive region. Under the optimization of the liquid-crystal cell and alignment used in the transmissive and reflective areas, the transmissive and reflective parts have similar gamma curves. An identical response time in both the transmissive and reflective regions and a desirable viewing angle for personal portable displays can also be obtained.