High-Contrast and Scattering-Type Transflective Liquid Crystal Displays Based on Polymer-Network Liquid Crystals

Abstract

The methods to enhance contrast ratios (CRs) in scattering-type transflective liquid crystal displays (ST-TRLCDs) based on polymer-network liquid crystal (PNLC) cells are investigated. Two configurations of ST-TRLCDs are studied and are compared with the common ST-TRLCDs. According to the comparisons, CRs are effectively enhanced by assembling a linear polarizer at the suitable position to achieve better dark states in the transmissive and reflective modes of the reported ST-TRLCDs with the optimized configuration, and its main trade-off is the loss of brightness in the reflective modes. The PNLC cell, which works as an electrically switchable polarizer herein, can be a PN-90° twisted nematic LC (PN-90° TNLC) cell or a homogeneous PNLC (H-PNLC) cell. The optoelectric properties of PN-90° TNLC and those of H-PNLC cells are compared in detail, and the results determine that the ST-TRLCD with the optimized configuration using an H-PNLC cell can achieve the highest CR. Moreover, no quarter-wave plate is used in the ST-TRLCD with the optimized configuration, so a parallax problem caused by QWPs can be solved. Other methods for enhancing the CRs of the ST-TRLCDs are also discussed.

Dielectric Meta-lattices with Tunable Reflectivity

“…A more popular way to develop a display panel that uses ambient light is by embedding a transflector in a liquidcrystal-display (LCD) system [7]. However, the working principle of the transflector is somewhat similar to that of a half-mirror, which results in a contrast ratio problem [1,8,9].…”

DFT Studies of Selected Epoxies with Mesogenic Units–Impact of Molecular Structure on Electro-Optical Response

“…Liquid crystal (LC) materials have found many applications in electrooptical devices [ 1 , 2 ]. In particular, they are still widely used in traditional LC displays [ 3 , 4 ]. In addition to standard LC properties, liquid crystals epoxies (LCE) also possess the ability to form liquid crystal polymer networks (LCPN) with well-defined structure and controllable molecular alignment [ 5 , 6 ].…”