Process and structures for selective deposition of liquid-crystal emulsion

Abstract

The invention relates to a method of forming a display comprising the steps of (a) providing a substrate; (b) forming a plurality of first conductors over the substrate, and optionally one or more circuits; (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; (d) drying the liquid carrier to form a layer of polymer-dispersed cholesteric-liquid-crystal domains in a continuous matrix; and (e) forming a plurality of second conductors, electrically isolated from the first conductors, over the layer of polymer-dispersed liquid-crystal domains so that an electric field between the second conductors and the uncoated portions of the first conductors is capable of changing the optical state of the polymer-dispersed cholesteric liquid-crystal material. The absence of a coating over the second conductors permits connection to the first conductors without additional processing steps. The invention is also directed to a display element made by the method and to an array of display elements that represent an intermediate in the production of the final form of the display elements.

1 . A method of making a bistable display, comprising: 
 obtaining a substrate;    applying a first conductive layer on the substrate;    masking at least a portion of the first conductive layer with a mask, leaving at least one exposed portion of the first conductive layer;    applying a second conductive layer over the mask and at least one exposed portion of the first conductive layer, wherein one of the first or second conductive layer comprises a circuit;    applying a bistable display material over the second conductive layer;    applying a third conductive layer over the bistable display material; and    connecting traces from the third conductive layer to at least a portion of the circuit.    
   
   
       2 . The method of  claim 1 , wherein the mask is removable, permanent, or has both removable and permanent portions.  
   
   
       3 . The method of  claim 1 , further comprising removing at least a portion of the mask after applying the bistable display material.  
   
   
       4 . The method of  claim 1 , wherein applying at least one of the first conductive layer, second conductive layer, bistable display material, or third conductive layer is done by printing.  
   
   
       5 . The method of  claim 1 , wherein applying at least one of the first conductive layer, second conductive layer, bistable display material, or third conductive layer is done by coating.  
   
   
       6 . The method of  claim 1 , further comprising removing at least a portion of the mask after applying the bistable display material and before connecting the second conductive layer to at least a portion of the circuit.  
   
   
       7 . The method of  claim 1 , wherein the bistable display material is cholesteric liquid crystal.  
   
   
       8 . The method of  claim 1 , further comprising masking at least a portion of the second conductive layer with a second mask.  
   
   
       9 . The method of  claim 8 , wherein the second mask can be removable, permanent, or have both removable and permanent portions.  
   
   
       10 . The method of  claim 1 , wherein the substrate is a continuous web.  
   
   
       11 . A continuously coated display formed by the method of  claim 1 .  
   
   
       12 . A printed display formed by the method of  claim 1 .  
   
   
       13 . A display element comprising: 
 a) a substrate;    b) a first conductive layer on the substrate;    c) a spacer element on the first conductive layer;    d) a second conductive layer on the spacer element;    e) a bistable material layer on the second conductive layer, wherein one of the first or second conductive layer comprises a circuit;    f) a third conductive layer on the bistable material, electrically connected to the circuit.    
   
   
       14 . The display element of  claim 13 , further comprising a second spacer element between the second conductive layer and the bistable material layer.  
   
   
       15 . The display of  claim 13 , wherein the bistable display material is cholesteric liquid crystal.