Patent ID: 7572394
Filing Date: 2009-08-11
Classification: G02F

Abstract:
1. A method for inducing or enhancing the threshold voltage of an electrophoretic displays comprising the steps of: (i) forming an electrophoretic dispersion comprising electrophoretic pigment particles dispersed in a fluorinated dielectric solvent or solvent mixture selected from the group consisting of perfluoroalkanes, perfluorocycloalkanes, perfluoroarylalkanes, perfluoro-tert-amines, perfluoropolyethers, hydrofluoropolyethers, poly(chlorotrifluoroethylene), and trifluoro(trifluoromethyl)-oxirane homopolymers, wherein said fluorinated dielectric solvent or solvent mixture comprises a dye or pigment in addition to the electrophoretic pigments particles; (ii) adding a fluorinated threshold agent of fluorinated dyes or fluorinated pigments selected from the group consisting of phthalocyanine, naphthalocyanine, anthraquinone, perylene, quinacridone, diketopyrrolopyrrole, naphthalimide, diazine, polyaniline and porphyrin to the electrophoretic dispersion, (iii) filling the resulting electrophoretic dispersion of (ii) into display cells of the electrophoretic display.