Method for measuring the cell gap in liquid-crystal displays

Filip Bruyneel; Herbert De Smet; Jan M.A. Vanfleteren; Andre Van Calster

doi:10.1117/1.1337036

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1 February 2001 Method for measuring the cell gap in liquid-crystal displays

Filip Bruyneel, Herbert De Smet, Jan M.A. Vanfleteren, Andre Van Calster

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Optical Engineering, 40(2), (2001). https://doi.org/10.1117/1.1337036

A method for measuring the cell gap of liquid-crystal displays (LCDs) is presented. It is based on analyzing the interference spectrum of white light reflected by the LCD. It can be used before or after filling the LCD. The method is applicable for LCDs whose operation is based on the polarization or the scattering of light. Four methods for the calculation of the cell gap are presented. The first method is based on the wavelengths corresponding with the peaks in the interference spectrum. Two other methods use analog and digital filtering techniques to filter out all the irrelevant information in the interference spectrum; the cell gap is then calculated with fast Fourier transform (FFT) or the inverse FFT. In the fourth method an empirical model is fitted to the measured interference spectrum.

©(2001) Society of Photo-Optical Instrumentation Engineers (SPIE)

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Filip Bruyneel, Herbert De Smet, Jan M.A. Vanfleteren, and Andre Van Calster "Method for measuring the cell gap in liquid-crystal displays," Optical Engineering 40(2), (1 February 2001). https://doi.org/10.1117/1.1337036

Published: 1 February 2001

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