Alignment Technique for Thin-Film-Transistor Liquid-Crystal Displays

In high-definition thin-film-transistor liquid-crystal displays (TFT-LCDs), it is important to establish the stability of liquid-crystal molecule alignment. In this paper, we describe the relation between pretilt angle and reverse tilt disclination in the high-definition TFT-LCD at 60°C. We conclude that a pretilt angle of more than 3° is required to prevent the occurrence of the reverse tilt disclination. Next, we consider this result, using a brief computer simulation on the electric field distribution in the TFT-LCD. Then, we describe the temperature dependence of the pretilt angle. We conclude that we can control the magnitude of pretilt angle by changing liquid crystal, polyimide material and process conditions, but the pretilt angle decreases at the same rate as the temperature becomes higher, without dependence on these parameters.