INITIATION OF OPERATING DEFECTS IN TWISTED NEMATIC LIQUID-CRYSTAL DISPLAYS

Twisted nematic liquid crystal displays are shown to fail in several unique ways; redox reactions damage electrode and liquid crystal material as a result of rectification produced because of polarity dependent electrosorption; hydrodynamic instabilities under certain conditions of conductance and electrode spacing result in disclinations which when anchored reduced contrast on the active areas; flow across edges produces disclination loops at certain edges determined by the fringing fields and the tilt and twist symmetry of the liquid orientation; flow combined with redox reactions yield changes in alignment at certain edges of the electrode pattern. The roll of individual fluid and package parameters and their interaction in producing these defects is indicated. © 1979, The Electrochemical Society, Inc. All rights reserved.