Process and structures for selective deposition of liquid-crystal emulsion

1. A method of forming a display element comprising:

a) providing a flexible web;

b) forming a plurality of first conductors over said flexible web;

c) depositing a layer of cholesteric liquid-crystal material, in the form of droplets of liquid crystal in a liquid carrier, over a preselected area of each of said first conductors so that a preselected portion of each of said first conductors is uncoated, wherein, the layer of cholesteric liquid-crystal material is simultaneously deposited on a plurality of display elements on the flexible web;

d) drying said liquid carrier to form a layer comprising domains of polymer-dispersed cholesteric liquid-crystal in a continuous matrix;

e) forming a plurality of second conductors, electrically isolated from the first conductors, over said layer of polymer-dispersed liquid-crystal domains so that an electric field between the second conductors and said uncoated portions of the first conductors is capable of changing the optical state of the polymer-dispersed cholesteric liquid-crystal.

2. A method of forming a display element comprising:

a) providing a substrate;

b) forming first conductors over said substrate;

c) masking portions of said first conductors;

d) depositing a layer of cholesteric liquid-crystal material, in the form of droplets of liquid crystal in a liquid carrier, over a preselected area of each of said first conductors so that a preselected portion of each of said first conductors is uncoated;

e) drying said liquid carrier to form a layer comprising domains of polymer-dispersed cholesteric liquid-crystal in a continuous matrix;

f) forming a plurality of second conductors, electrically isolated from the first conductors, over said layer of polymer-dispersed liquid-crystal so that an electric field between the second conductors and said uncoated portions of the first conductors is capable of changing the optical state of the polymer dispersed cholesteric liquid crystal material.

3. The method of claim 2 wherein the mask is removed prior to forming a plurality of second conductors.

4. The method of claim 2 wherein the mask is not removed prior to forming a plurality of second conductors, but is maintained as integral to the completed display element.

5. The method of claim 2 wherein, in step (d), the cholesteric liquid-crystal material is spread over the mask by a doctor blade.

6. The method of claim 1 wherein the substrate is one of multiple substrates on a common web.

7. The method of claim 1 wherein the liquid carrier comprises gelatin in solution.

8. The method of claim 1 wherein the first conductors are transparent.

9. The method of claim 8 wherein the first conductors are made from a vacuum deposited transparent conductor.

10. The method of claim 1 wherein the first conductors are laser etched.

11. The method of claim 1 wherein the second conductors are vacuum deposited or solvent coated.

12. A display element comprising:

a) a substrate;

b) a plurality of first conductors formed over said substrate;

c) a layer comprising polymer-dispersed liquid-crystal in the form of domains of liquid crystal in a continuous matrix, which layer is formed over said first conductors so as to leave a portion of each of said first conductors uncoated; and

d) between the first conductors and the substrate, a spacer element that has openings that are aligned with the areas covered by the layer of polymer-dispersed liquid-crystal;

e) a plurality of second conductors, electrically isolated from the first conductors, over said layer of polymer-dispersed liquid-crystal so that an electric field to the second conductors and said uncoated portions of the first conductors is capable of changing the optical state of the polymer dispersed liquid crystal.

13. An array of display elements, each display element comprising:

a) a common substrate which is a continuous web;

b) two or more sets of first conductors, each set comprising a plurality of first conductors forming a single display element, formed over said common substrate;

c) over each set of first conductors, a layer of polymer-dispersed liquid-crystal material deposited in a manner that leaves a portion of the first conductors in each set uncoated, wherein the layer of polymer-dispersed cholesteric liquid-crystal material in each display element is non-contiguous and separate from the layer of polymer-dispersed cholesteric liquid-crystal material in every other display element on the common substrate;

d) a corresponding number of sets of second conductors, each set of second conductors comprising a plurality of second conductors forming a single display element with a corresponding set of first conductors, which sets of second conductors are each formed over each layer of polymer-dispersed liquid-crystal material, such that, for each set, an electric field applied to said second conductors and said uncoated portions of said first conductors is capable of changing the optical state of the polymer-dispersed cholesteric-liquid crystal material in a preselected portion of the layer of polymer-dispersed cholesteric liquid-crystal material.

14. The array of display elements in claim 13 wherein the common substrate is a non-continuous sheet.

15. The array of display elements in claim 13 wherein the preselected portion of the layer of polymer-dispersed cholesteric liquid-crystal material covers the overlapping portions of the first and second conductors.

16. The array of display elements in claim 13 wherein the sets of first conductors, each set in combination with the corresponding set of second conductors, are arrayed in a plurality of columns and rows.