Reflective display based on liquid crystal materials

1 . A high contrast reflective display comprising at least one substrate, at least one electrically conductive layer and at least one electronically modulated imaging layer, wherein said electronically modulated imaging layer comprises a close-packed, ordered monolayer of domains of electrically modulated material in a fixed polymer matrix.

2 . The high contrast reflective display of claim 1 wherein said substrate is flexible.

3 . The high contrast reflective display of claim 1 wherein said substrate is transparent.

4 . The high contrast reflective display of claim 3 further comprising a second substrate.

5 . The high contrast reflective display of claim 1 wherein said electrically conductive layer a surface conductivity of less than 10 4 ohms/sq.

6 . The high contrast reflective display of claim 1 wherein said electrically conductive conductive layer comprises ITO.

7 . The display of claim 1 wherein said electrically conductive layer comprises polythiophene.

8 . The high contrast reflective display of claim 1 further comprising at least a second electrically conductive layer, wherein said at least one close-packed, ordered monolayer of electrically modulated material in a crosslinked polymer matrix is between said at least one electrically conductive layer and said second conductive layer.

9 . The high contrast reflective display of claim 1 wherein at least one electrically conductive layer is patterned.

10 . The high contrast reflective display of claim 1 further comprising a means for applying electrical field across said at least one close-packed, ordered monolayer of electrically modulated material in a fixed polymer matrix.

11 . The high contrast reflective display of claim 1 wherein said electrically modulating material is a liquid crystalline material.

12 . The high contrast reflective display of claim 1 wherein said electrically modulated material comprises a bistable liquid crystalline material.

13 . The high contrast reflective display of claim 12 wherein said bistable liquid crystalline material comprises a chiral nematic liquid crystal layer.

14 . The high contrast reflective display of claim 1 wherein said at least one close-packed, ordered monolayer of electrically modulated material is a hexagonally closest packed monolayer of light modulating material.

15 . The high contrast reflective display of claim 1 wherein said at least one close-packed, ordered monolayer of electrically modulated material has a repeat pattern or periodicity with a repeat distance of the order of the wavelength of visible light.

16 . The high contrast reflective display of claim 1 wherein said fixed polymer matrix is a crosslinked polymer matrix.

17 . The high contrast reflective display of claim 1 wherein said fixed polymer matrix is not rigid prior to drying.

18 . The high contrast reflective display of claim 1 wherein said fixed polymer matrix is in a random configuration if the coating is dried at a temperature that is above the sol-gel transition temperature.

19 . The high contrast reflective display of claim 1 wherein said fixed polymer matrix prior to crosslinking has a sol-gel transition temperature or thermal gelation temperature or chill set temperature below 23° C.

20 . The high contrast reflective display of claim 1 wherein said fixed polymer matrix prior to crosslinking has a sol-gel transition temperature or thermal gelation temperature or chill set temperature below 10° C.

21 . The high contrast reflective display of claim 1 wherein said electrically modulated material to said fixed polymer matrix ratio is from 6:1 to 0.5:1

22 . The high contrast reflective display of claim 1 wherein said electrically modulated material to said fixed polymer matrix ratio is 3:1.

23 . The high contrast reflective display of claim 1 wherein said fixed polymer matrix comprises gelatin.

24 . The high contrast reflective display of claim 23 wherein said gelatin is in a random coil configuration if the coating is dried at a temperature that is above the sol-gel transition temperature of gelatin.

25 . The high contrast reflective display of claim 23 wherein said gelatin is fish gelatin.

26 . The high contrast reflective display of claim 25 wherein said fish gelatin is deep water fish gelatin.

27 . The high contrast reflective display of claim 23 wherein said gelatin has lower imino acid content than bovine gelatin.

28 . The high contrast reflective display of claim 1 wherein said fixed polymer matrix further comprises a hardening agent.

29 . The high contrast reflective display of claim 1 further comprising a protective layer.

30 . The high contrast reflective display of claim 29 wherein said protective layer comprises gelatin.

31 . The high contrast reflective display of claim 30 wherein said gelatin contains molecules in a helix configuration.

32 . The high contrast reflective display of claim 1 wherein said electrically modulated imaging layer further comprises polyvinylalcohol (PVA).

33 . The high contrast reflective display of claim 1 wherein said at least one electronically modulated imaging layer has a RMS surface roughness of less than 1.5 microns

34 . The high contrast reflective display of claim 1 comprising a stack of at least two of said high contrast reflective displays, wherein a stack comprises at least one substrate, at least one electrically conductive layer and at least one close-packed, ordered monolayer of domains of electrically modulated material in a fixed polymer matrix.

35 . A method of making a high contrast reflective display comprising:

providing a substrate;

applying a conductive layer;

applying at least one layer of domains of electrically modulated material in a polymer matrix;

drying the at least one applied layer of said domains of electrically modulated material in a polymer matrix at a temperature above the chill set temperature or sol-gel transition temperature of said polymer matrix to permit self-assembly of said domains of electrically modulated material into a close-packed monolayer of said domains of electrically modulated material; and fixing said polymer matrix to preserve said close-packed monolayer of domains of electrically modulated material.

36 . The method of claim 35 further comprising:

applying a second aqueous layer containing gelatin;

chill setting said second aqueous layer containing gelatin; and

drying said second aqueous layer.