Fast Responding Supertwisted Nematic Liquid Crystal Displays

8 Fast Responding Supertwisted Nematic Liquid Crystal Displays 

N scanning lines are divided into N/L subgroups, where each subgroup contains L scanning lines. For Alt-Pleshko addressing 

for active addressing L=A, while typically for multiline addressing the value of 2v=4... 7. AA and MLA require a different set of row and column signals from Alt-Pleshko addressing. These will be considered in the following  

The signal for row i and column j at time t are described by functions F,(0 and Gj(t). The voltage across pixel ij is given by 

A detailed mathematical analysis shows that the row functions Fi(t) must be a set of orthonormal functions to obtain an optimum selection ratio. The time dependent column signals Gj(t) must be calculated by summation of the product of a matix element and the row functions F, (t) over the number of scanning lines L per subgroup N/L  

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It can be safely predicted that applications of liquid crystals will expand in the future to more and more sophisticated areas of electronics. Potential applications of ferroelectric liquid crystals (e.g. fast shutters, complex multiplexed displays) are particularly exciting. The only LC that can show ferroelectric property is the chiral smectic C. Viable ferroelectric displays have however not yet materialized. Antifer-roelectric phases may also have good potential in display applications. Supertwisted nematic displays of twist artgles of around 240° and materials with low viscosity which respond relatively fast, have found considerable application. Another development is the polymer dispersed liquid crystal display in which small nematic droplets ( 2 gm in diameter) are formed in a polymer matrix. Liquid crystalline elastomers with novel physical properties would have many applications. 

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