Misalignment failure mechanisms which are a problem in twisted nematic liquid-crystal display devices were investigated. A life test which changes the driving conditions of the applied multiplexing voltage was implemented for devices which use estercy-clohexane liquid crystals. The life tests showed that misalignment life is longer with a lower voltage, a smaller duty ratio, and a higher frequency. These results are highly appropriate for models with alternating current electrolysis of the liquid-crystal material. In addition, electrostatic capacity and applied voltage properties were used to study the relationship of liquid-crystal dielectric anisotropy and the coupling coefficient with temporal misalignment changes. The coupling coefficient decreases along with misalignment failure
Published in:
Reliability, IEEE Transactions on
(Volume:40
,
Issue:
3
)
Date of Publication: Aug 1991