Thermal-Mechanical Effects of Rugged Liquid Crystal Displays on Optical Performance

The indium-tin oxides (ITO) glasses coating with anti-reflective (AR) films are usually bonding with commercial off-the-shelf LCDs for ruggedization. The rugged LCDs have higher contrast ratio. The display mura also easily happen on the rugged LCDs as the fact that the thermal and mechanical properties of optical adhesive, LC plate, and ITO glass are different. This paper focuses on the stress-induced birefringence of LC cell and try to analyze the possible reasons of the display mura. As the properties of optical adhesive have direct effects on the simulation results, both the practical measurement and the simulation are done for parameter optimization. The simulation model of the rugged LCD with a bubble in the middle of the optical adhesive is established. The simulation results show that the stress happens on the LC plate when the temperature changes. Even only 5.6% stress changes can lead to the light transmittance decreases from 99% to 5.7%, which should try best to avoid.