Multistable cholesteric liquid crystal devices driven by width-d

Details Multistable cholesteric liquid crystal devices driven by width-d Multistable cholesteric liquid crystal devices driven by width-d

1997-04-17

1999-03-30

Sikes, William L.

Liquid crystal cells, elements and systems

Particular excitation of liquid crystal

Electrical excitation of liquid crystal

349175, 349 33, 345 98, G07F 11343

Patent

active

058895663

ABSTRACT:
A light modulating apparatus containing cholesteric liquid crystals capable of indefinite zero field retention of optical images, including full color and complete gray scale capability, is described. This invention is predicated on establishment of zero field multistable liquid crystal domains representing a continuous distribution of states ranging from the highly reflective planar to the light-scattering focal-conic structures. The zero field multistable domain structure stability is achieved by controlling solid surface-liquid crystal boundary interactions to provide essential equalization of the total system energy of each of the domain structures. This is the first time this equalization, and thus zero field multistability, has been achieved without the use of a polymer gel addition to create rigid polydomains in the liquid crystal mix. The establishment of a particular domain structure, and thus the degree of light reflection or scattering by individual display pixels, is controlled using either a single relatively long voltage pulse or a number of shorter duration successive voltage pulses. The zero field multistability achieved is remarkably stable against both mechanical shocks and thermal variations. Because these displays eliminate the need for backlighting and image refreshing energy input, they represent ultra low power consumption devices ideal for use with portable display systems. Because these displays also eliminate the need for polarizers, analyzers, retarder and color filters, they are ultra thin and particularly well suited for use in ultra large (i.e., billboard) displays using a building block approach which retains total spatial integrity. These displays can also be fabricated as flexible all-plastic units again utilizing the overall thinness of these devices.

REFERENCES:
patent: 3703331 (1972-11-01), Goldmacher et al.
patent: 3730607 (1973-05-01), Grabmaier et al.
patent: 3806230 (1974-04-01), Haas
patent: 4333708 (1982-06-01), Boyd et al.
patent: 4505548 (1985-03-01), Berreman et al.
patent: 5046830 (1991-09-01), Nakanowatari
patent: 5251048 (1993-10-01), Doane et al.
patent: 5272552 (1993-12-01), Yoshinaga et al.
D.K. Yang and J.W. Doane, "Cholesteric Liquid Crystal/Polymer Gel Dispersions: Reflective Display Applications," SID 92 Digest, pp. 759-761.
J.W. Doane, D.K. Yang and Z. Yaniv, "Front-Lit Flat Panel Display from Polymer Stabilized Cholesteric Textures," Japan Display '92, pp. 73-76.
Y.K. Fung, D.K. Yang, J.W. Doane and Z. Yaniv, "Projection Display from Polymer Stabilized Cholesteric Textures," The 13th International Display Research Conference (Aug. 31-Sep. 3, 1993), SID France.
D.K. Yang, L.C. Chien and J.W. Doane, "Cholesteric Liquid Crystal/Polymer Gel Dispersion Bistable at Zero Field," Conference Record, International Display Research Conference (Oct. 1993), p. 44, SID.
J.W. Doane, D.K. Yang and L.C. Chien, "Current Trends in Polymer Dispersed Liquid Crystals," 1991 IEEE, pp. 175-178.

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