Title :
Simultaneous measurement of twist angle and cell gap of a twisted nematic cell by an optical method
Author_Institution :
IBM Thomas J. Watson Res. Center, Yorktown Heights, NY, USA
Abstract :
An optical method is presented which makes it possible to measure simultaneously the twist angle and the cell gap of a filled twisted nematic liquid crystal display that has an arbitrary unknown twist angle between 0 degrees and 360 degrees . It can also determine the sense of handedness of the twist and the two rubbing directions of an unknown panel. Using this method, the measurement uncertainty of the cell gap is within 1% and measurement uncertainties of the twist angle and rubbing directions are within 1 degrees .<>
Keywords :
liquid crystal displays; nematic liquid crystals; cell gap; liquid crystal display; measurement uncertainty; optical method; rubbing directions; twist angle; twisted nematic cell; Computer displays; Goniometers; Liquid crystal displays; Optical feedback; Optical films; Optical filters; Optical polarization; Optical refraction; Optical sensors; Phase measurement;
Conference_Titel :
Display Research Conference, 1991., Conference Record of the 1991 International
Conference_Location :
San Diego, CA, USA
Print_ISBN :
0-7803-0213-3
DOI :
10.1109/DISPL.1991.167467
