Electro-optic characteristics of 4-domain vertical alignment nematic liquid crystal display with interdigital electrode

Abstract

We have fabricated a vertically aligned 4-domain nematic liquid crystal display cell with thin film transistor. Unlike the conventional method constructing 4-domain, i.e., protrusion and surrounding electrode which needs additional processes, in this study the pixel design forming 4-domain with interdigital electrodes is suggested. In the device, one pixel is divided into two parts. One part has a horizontal electric field in the vertical direction and the other part has a horizontal one in the horizontal direction. Such fields in the horizontal and vertical direction drive the liquid crystal director to tilt down in four directions. In this article, the electro-optic characteristics of cells with 2 and 4 domain have been studied. The device with 4 domain shows faster response time than normal twisted-nematic and in-plane switching cells, wide viewing angle with optical compensation film, and more stable color characteristics than 2-domain vertical alignment cell with similar structure.

Vertical alignment nematic liquid crystal cell controlled by double-side in-plane switching with positive dielectric anisotropy liquid crystal

“…As the result, in DSIPS cell, maximum transmittance is obtained when the phase retardations are simultaneously optimized on the electrode and in the gap between the electrodes. Hence, total transmittance decreases when the retardation is higher than 0.42 m. This behavior is similar to VA-IPS mode, 12 whereas operating voltage decreases due to the expansion of the bulk region, which is not influenced by the surface. As d increases, therefore, LC directors of the bulk region easily tilt down at the same voltage.…”

“…Moreover, negative dielectric anisotropy ͑⌬͒ LCs usually have higher viscosity, smaller ⌬ value, and are more expensive than positive ⌬ LCs. Previously, in order to overcome these drawbacks, VA mode driven by in-plane field ͑VA-IPS͒ was suggested, 11,12 where positive ⌬ LCs were used and two domain structure was obtained without additional processes. VA-IPS cell structure is the same as IPS mode, where positive ⌬ LCs are vertically aligned under the crossed polarizers.…”

Surfactant-doped reverse-mode polymer-dispersed liquid crystal display with enhanced properties

“…In the recent years, homeotropic alignment of liquid crystals or vertical orientation has got worldwide applications in liquid crystal displays. [3][4][5] Mainly, the vertical orientation of liquid crystals is used in reverse-mode polymer-dispersed liquid crystal (R-PDLC) displays. This particular kind of PDLC device becomes transparent during OFF state and light scattering during ON state; thus operating opposite to the normal-mode PDLCs.…”

Light Leakage of Multidomain Vertical Alignment LCDs Using a Colorimetric Model in the Dark State

“…In-Plane Switching (IPS) [1,2] and Multidomain Vertical Alignment (MVA) [3][4][5] are widely used for highend LCD products. The MVA LCD has a superior contrast ratio at normal viewing directions, wide viewing angle, and poor color dispersion.…”