Viewing Angle and Voltage Dependence of the Visibility of Cell Gap Defects in LCD Panels

Perception of visible defects induced by local cell gap variations in liquid crystal display (LCD) panels is studied as a function of the viewing direction and applied voltage. Our results are reported in terms of the LCD sensitivity parameter defined in our previous publication and can be readily used in conjunction with the psycho-physical models of Mura perception. We apply our methods to a particular example of a normally white TN LCD and show that the Mura visibility depends strongly on the viewing angle as well as the applied voltage. We conclude that a complete study of the -parameter as a function of the viewing angle and applied voltage is crucial in the correct assessment of the sensitivity of an LCD panel to cell gap variation.