Effect of atmospheric plasma and rubbing coprocessing on liquid crystal alignment on a polyimide layer

Abstract We investigated the effect of combining a rubbing process with an atmospheric plasma process on liquid crystal (LC) alignment on a polyimide layer. When the two processes were used together, the pretilt angles of 2.150° and 2.601° were excellent than when the rubbing-only process was performed. Concerning electro-optical characteristics, the low-power driving voltage was less than 2.5 V and the effective switching voltage was more than 20% lower than for the conventional rubbing-only process. In addition, the thermal stability and alignment characteristics after treatment at 150 °C were superior to those obtained when the atmospheric plasma-only process was used. This study suggests a route to the manufacture of LC displays having better performance and efficiency than achievable with current LC alignment methods.