Use of PTFE alignment layers in passive addressed SSFLC displays

Polytetrafluoroethylene (PTFE or Teflon®) layers have been developed as orientation films in order to produce ferroelectric liquid crystals displays with improved addressing behaviour. PTFE layers have been friction deposited on glass substrate with ITO electrodes at various temperatures in the range 130°C-200°C. The PTFE layers have been used to assemble displays which were addressed and showed no hysteresis, reduced image sticking and reduced switching time with respect to standard test cells employing rubbed polymers as alignment layers. In order to assure the best electro-optical performance, PTFE films have been characterized from the point of view of uniformity and thickness as function of deposition parameters.