Alignment and Bistability of Ferroelectric Liquid Crystals

For the alignment of SSFLCs, four aspects were considered to be of major importance [1]  

Of these four parameters, the second and the fourth are related to the bistability. In this section, the alignment phenomena or the problems related to bistability will be mainly discussed, together with the control of defects. 

Consider the SXGA display for monitor usage (see Fig. 5.2.1). In the case of the SXGA display, the number of scamiing electrodes is 1024, or the duty ratio is 1/1024. Fbr the usual line-sequential scheme, the fi-ame frequency of the LCD is 60 Hz, or 60 pictures are formed every second. So, the period of one frame (frame rate) or 

16-l-16nth) scanning line. In the case of SXGA displays in which 400 ps is 

If a perfect memory property could be realized, the refreshing process would not be necessary. Only by a partial access scheme could a higji contrast ratio be obtained. On the other hand, in the case of SSFLCs with a poor memory property, the refreshing process must be carried out frequently, and the number of scanning lines would be limited. For SSFLCs, memory property determines both the number of scanning lines and the contrast ratio. 

2 1/3 Bias Driving Wave Fbrm Signal (1) is applied to the selected scanning lines. Signals (3), (4) or (5) are applied to the signal lines (6). 

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Palto, S.P., Geivandov, A.R., Bamik, M.I., Blinov, L.M. The new role of alignment layers in bistable switching of ferroelectric liquid crystals. Numerical simulations and experimental results. Ferroelectrics 310, 95-109 (2004)... 

In the sections on smectic liquid crystals, first the alignment and molecular orientation of surface stabilized ferroelectric liquid crystals (SSFLCs) are treated in detail. Next, the alignment technologies needed for the occurrence of bistability are detailed. Furthermore, liquid crystalline devices made of AFLC materials and the applications of FLC and AFLC materials to active matrix devices are discussed. 

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