Study on decrease of the twist angle in TN cells

Abstract

In the twisted nematic liquid-crystal (TN-LC) cells with rubbed alignment films of relatively weak anchoring strength, the twist angles decrease after the LC material was injected into the empty cells. We have measured the time dependence of the twist angle in the TN-LC cells. The twist angle rapidly decreases in the TN-LC cells using polyvinyl alcohol (PVA) film with lower saponification degree. However, the same twist angle can be retained before and after the voltage of 15V was applied for 12h and removed.