A temperature compensated overdrive scheme for vertically aligned liquid crystal displays
Pieter J. M. Vanbrabant, Nathalie Velthoven-Dessaud, Jan F. Strömer, Kristiaan Neyts · Ghent University Academic Bibliography (Ghent University) · 2009
Vertically aligned liquid crystal displays (VA-LCDs) are very attractive for information displays because of their excellent contrast ratio, low power consumption and wide viewing angle. However, the strong influence of backflow on the dynamic behaviour of VA-LCDs has been demonstrated. To optimize the switching performance of VA-LCDs, the limitations due to this complex flow phenomenon should be considered because backflow inhibits application of conventional overdrive techniques to achieve fast switching. Based on accurate simulation of the (hydro)dynamic switching behaviour of VA-LCDs, we designed improved overdrive schemes taking into account the limitations due to backflow as a special case. The temperature sensitivity of a fixed overdrive table is eliminated by adapting the scheme to the simulated temperature variations of the dynamic behaviour. Experimental verification in the 25-75ºC range shows that this temperature compensating overdrive extends the optimized switching performance of today's LCDs to a much wider temperature range.