LATERAL ION PUMPING IN LIQUID CRYSTAL DISPLAYS

• Main Authors: VERSCHUEREN ALWIN R. M, NEYTS KRISTIAAN, STOJMENOVIK GORAN
• Format: Patent
• Language: English
• Published: 24.11.2006
• Subjects: DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

The present invention relates to the removal of ion (42, 44, 902) contaminations from liquid crystal layers (901) in liquid crystal display devices (900). The ions (42, 44, 902) are removed by means of so called ion pumping, which utilizes the anisotropic viscosity of liquid crystals. The ions (42, 44, 902) are pumped up and down in the liquid crystal layer by means of an alternating electric filed. The alternating electric field simultaneously alters the alignment of directors (41) in the liquid crystal. The viscosity in the liquid crystal is related to the director directions, and the ions (42, 44, 902) are thereby moved in non-closed trajectories (43, 45). The inventive ion pumping can be further improved using an asymmetric or biased alternating electric field.