Flexible Electrophoretic-Type Display

Abstract

An electrophoretic-type display device including an array of microcells, where each microcell is formed by a microwell containing a quantity of ink and a polymer-based membrane connected to upper edges of the microwell. The membrane is formed by curing an aqueous or hydroalcoholic sealing solution that is overcoated on the ink-filled microwells. The ink includes an isoparaffinic-based or oil-based suspension fluid, and the peripheral side walls of the microwell have a surface energy in the range of 20 to 30 mN/m. The microwell material serves two purposes: to prevent displacement (floating) of the relatively light ink solution above the relatively heavy sealing solution, and to facilitate reliable attachment between the polymer membrane and microwell walls during subsequent curing.

1 . A display device including a plurality of microcells, each microcell comprising:
 a microwell including a lower wall and one or more peripheral side walls extending upward from the lower wall;   an ink solution contained within the microwell, the ink solution including a suspension fluid; and   a membrane attached to upper edges of the peripheral side walls such that the ink solution is sealed inside of a chamber defined by the membrane and the lower wall and peripheral side walls of the microwell,   wherein the membrane comprises at least one of an alkylester of PVM/MA copolymer, a PVP/VA copolymer, and a silicone copolyol.   
   
   
       2 . The display device according to  claim 1 , wherein the peripheral side walls of the microwell comprise a surface energy in the range of 20 to 30 mN/m. 
   
   
       3 . The display device according to  claim 1 , wherein the microwell has a width in the range of 10 2  to 10 3  microns, and a height in the range of 5 to 1000 microns. 
   
   
       4 . The display device according to  claim 1 , wherein the wall material comprises one of a curable polymer and an epoxy-type, near-UV photoresist. 
   
   
       5 . The display device according to  claim 1 , wherein the suspension fluid comprises one of a silicone-based oil and ISOPAR. 
   
   
       6 . The display device according to  claim 1 , wherein the ink solution comprises one of an electrophoretic ink and a magnetophoretic ink. 
   
   
       7 . A display device including a plurality of microcells, each microcell comprising:
 a microwell including a lower wall and one or more peripheral side walls extending upward from the lower wall;   an ink solution contained within the microwell, the ink solution including a plurality of particles in a suspension fluid; and   a polymer-based membrane attached to upper edges of the peripheral side walls such that the ink solution is sealed inside of a chamber defined by the membrane and the lower wall and peripheral side walls of the microwell,   wherein the suspension fluid comprises one of an isoparaffinic-based solvent and a silicone oil-based solvent, and   wherein the membrane comprises at least one of an alkylester of PVM/MA copolymer, a PVP/VA copolymer, and a silicone copolyol.   
   
   
       8 . The display device according to  claim 7 , wherein the peripheral side walls of the microwell comprise a surface energy in the range of 20 to 30 mN/m. 
   
   
       9 . The display device according to  claim 7 , wherein the microwell has a width in the range of 10 2  to 10 3  microns, and a height in the range of 5 to 1000 microns. 
   
   
       10 . The display device according to  claim 7 , wherein the wall material comprises one of a curable polymer and an epoxy-type, near-UV photoresist. 
   
   
       11 . The display device according to  claim 7 , wherein the suspension fluid comprises one of a silicone-based oil and ISOPAR. 
   
   
       12 . The display device according to  claim 7 , wherein the ink solution comprises one of an electrophoretic ink and a magnetophoretic ink. 
   
   
       13 . A display device including a plurality of microcells, each microcell comprising:
 a microwell including a lower wall and one or more peripheral side walls extending upward from the lower wall;   one of an electrophoretic ink and a magnetophoretic ink contained within the microwell; and   a membrane attached to upper edges of the peripheral side walls such that said one of said electrophoretic ink and a magnetophoretic ink is sealed inside of a chamber defined by the membrane and the lower wall and peripheral side walls of the microwell,   wherein the membrane comprises at least one of an alkylester of PVM/MA copolymer, a PVP/VA copolymer, and a silicone copolyol.   
   
   
       14 . The display device according to  claim 13 , wherein the peripheral side walls of the microwell comprise a surface energy in the range of 20 to 30 mN/m. 
   
   
       15 . The display device according to  claim 13 , wherein the microwell has a width in the range of 10 2  to 10 3  microns, and a height in the range of 5 to 1000 microns. 
   
   
       16 . The display device according to  claim 13 , wherein the wall material comprises one of a curable polymer and an epoxy-type, near-UV photoresist. 
   
   
       17 . The display device according to  claim 13 , wherein said one of said electrophoretic ink and a magnetophoretic ink comprises one of a silicone-based oil and ISOPAR.