Single Cell Gap Transflective TFT-LCDs based on Homogeneous LC Alignment

Abstract

In this thesis, we propose and demonstrate the simulations results obtained for three new designs of single cell gap transflective TFT-LCDs (TR-LCDs) that are based on homogeneously aligned (or Parallel Aligned, PA) liquid crystal (LC) layers. Our simulation results are obtained through the use of a professional and reliable 2D-LCD simulation software “2DimMos” purchased from Germany. Due to the double-path experienced by the reflected light, a single cell gap TR-LCD usually has the problem such that its voltage-dependent transmittance and reflectance curves (V-T & V-R) do not match each other very well, which often leads to very poor optical efficiency. This problem is, in general, overcome by the use of a rather complicated double cell gap design. In our studies, we propose and explore the potential possibility of three new designs of single cell gap TR-LCD such that they can achieve much better matched V-T and V-R curves and hence higher optical efficiency. These three designs are named as follows: i) Bottom-mode PA-FFS TR-LCD, ii) Top-mode PA-FFS TR-LCD, iii) Dual PA mode TR-LCD. The simulation results obtained so far demonstrate that these three designs can indeed, in principle, achieve much better matched Electro-Optic curves for both transmitted and reflected lights and hence result in improved optical efficiency. Simpler device structure and fabrication process are possible by further developments and optimizations.