We have made a new type of cholesteric liquid‐crystal display device that is bistable in the absence of an applied field. One of the two stable states has 360° of twist between the two surfaces. The other is an untwisted state, like an unstrained nematic with all directors parallel. One method of switching is to apply a pulse of about 3 V or more between the cell surfaces, to obtain the twisted state or a pulse of about 1.5–2 V to obtain the untwisted state. Lesser pulses have no lasting effect. These switching characteristics have promise for displays with large numbers of characters.

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© 1980 American Institute of Physics.
1980
American Institute of Physics
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