Processes for the production of electro-optic displays, and color filters for use therein

Abstract

Processes are provided for depositing multiple color filter materials on a substrate to form color filters. In a first process, the surface characteristic of a substrate is modified by radiation so that a flowable form of a first color filter material will be deposited on a first area, and converted to a non-flowable form. A second color filter material can then be deposited on a second area of the substrate. In a second process, first and second color filter materials are deposited on separate donor sheets and transferred by radiation to separate areas of the substrate. A third process uses flexographic printing to transfer the first and second color filter materials to the substrate.

1 . A color electrophoretic display comprising:
 an electrophoretic medium;   a front electrode; and   an opaque backplane comprising first and second color filter materials.   
     
     
         2 . The color electrophoretic display of  claim 1 , wherein the electrophoretic display is produced by laminating the electrophoretic medium and the front electrode to the backplane. 
     
     
         3 . The color electrophoretic display of  claim 1 , wherein the opaque backplane is produced by:
 providing an opaque backplane comprising first and second sets of electrodes;   depositing on the backplane a coating of a material having a surface characteristic capable of being modified by radiation;   applying radiation to a first area of the coating aligned with the first set of electrodes but not to a second area of the coating, said second area of the coating being aligned with the second set of electrodes;   depositing a flowable form of a first color filter material on to the first area of the coating;   converting the flowable form of the first color filter material on the first area of the coating to a non-flowable form;   applying radiation to the second area of the coating; and   depositing a second color filter material on to the second area of the coating.   
     
     
         4 . The color electrophoretic display of  claim 1 , wherein the electrophoretic medium comprises a plurality of electrically charged particles disposed in a fluid and capable of moving through the fluid under the influence of an electric field. 
     
     
         5 . The color electrophoretic display of  claim 4 , wherein the electrically charged particles and the fluid are confined within a plurality of capsules or microcells. 
     
     
         6 . The color electrophoretic display of  claim 4 , wherein the electrically charged particles and the fluid are present as a plurality of discrete droplets surrounded by a continuous phase comprising a polymeric material. 
     
     
         7 . The color electrophoretic display of  claim 4 , wherein the fluid is gaseous. 
     
     
         8 . The color electrophoretic display of  claim 1 , further comprising a protective layer. 
     
     
         9 . An electronic book reader, portable computer, tablet computer, cellular telephone, smart card, sign, watch, shelf label or flash drive comprising a color electrophoretic display according to  claim 1 . 
     
     
         10 . A color electro-optic display comprising a layer of electro-optic medium and a color filter produced by a process comprising:
 depositing on a substrate a coating of a material having a surface characteristic capable of being modified by radiation;   applying radiation to a first area of the coating but not to a second area thereof;   depositing a flowable form of a first color filter material on to the first area of the coating;   converting the flowable form of the first color filter material on the first area of the coating to a non-flowable form;   applying radiation to a second area of the coating; and   depositing a second color filter material on to the second area of the coating.   
     
     
         11 . The color electro-optic display according to  claim 10 , wherein the electro-optic material comprises a rotating bichromal member or electrochromic material. 
     
     
         12 . The color electro-optic display according to  claim 10 , wherein the electro-optic material comprises an electrophoretic material comprising a plurality of electrically charged particles disposed in a fluid and capable of moving through the fluid under the influence of an electric field. 
     
     
         13 . The color electro-optic display according to  claim 12 , wherein the electrically charged particles and the fluid are confined within a plurality of capsules or microcells. 
     
     
         14 . The color electro-optic display according to  claim 12 , wherein the electrically charged particles and the fluid are present as a plurality of discrete droplets surrounded by a continuous phase comprising a polymeric material. 
     
     
         15 . The color electro-optic display according to  claim 12 , wherein the fluid is gaseous. 
     
     
         16 . An electronic book reader, portable computer, tablet computer, cellular telephone, smart card, sign, watch, shelf label or flash drive comprising a color display according to  claim 10 .