Abstract: A forward osmosis system is disclosed which use a polymer switchable between a neutral form and an ionized form. The switchable polymer has a higher osmotic pressure at the ionized form than the neutral form, the ratio between the former and the latter is ?2. There is also disclosed a method for treating the polymer such that the ratio is improved. Use of polymers for forward osmosis is also disclosed.

Abstract: A color filter array is provided in an electro-optic display by ink jet printing a plurality of colored areas (22R, 22G, 22B) on one surface of a layer of electro-optic material (12), an adhesive layer or a protective layer. Alternatively, the ink jet printing may be effected on the same layers in various sub-assemblies used to produce electro-optic displays.

Abstract: A coating of an encapsulated electrophoretic medium is formed on a substrate (106) by dispersing in a fluid (104) a plurality of electrophoretic capsules (102), contacting at least a portion of a substrate (106) with the fluid (104); and applying a potential difference between at least a part of the portion of the substrate (106) contacting the fluid (104) and a counter-electrode (110) in electrical contact with the fluid (104), thereby causing capsules (102) to be deposited upon at least part of the portion of the substrate (106) contacting the fluid (102). Patterned coatings of capsules containing different colors may be deposited in registration with electrodes using multiple capsule deposition steps. Alternatively, patterned coatings of capsules may be formed by applying a fluid form of an electrophoretic medium to a substrate, and applying a temporally varying voltage between an electrode and the substrate. The process may be repeated to allow for deposition of full color displays.

Abstract: A first electrophoretic medium comprises an electrically charged particle suspended in a suspending fluid, the particle having a polymeric shell having repeating units derived from at least one monomer the homopolymer of which is incompatible with the suspending fluid. A second, similar electrophoretic medium comprises a suspending fluid, and first and second types of electrically charged particle suspended in the suspending fluid, the two types of particle having differing optical characteristics but both having polymeric shells. The polymeric shells are arranged such that homoaggregation of the two types of particles is thermodynamically favored over heteroaggregation.

Abstract: A first electrophoretic medium comprises an electrically charged particle suspended in a suspending fluid, the particle having a polymeric shell having repeating units derived from at least one monomer the homopolymer of which is incompatible with the suspending fluid. A second, similar electrophoretic medium comprises a suspending fluid, and first and second types of electrically charged particle suspended in the suspending fluid, the two types of particle having differing optical characteristics but both having polymeric shells. The polymeric shells are arranged such that homoaggregation of the two types of particles is thermodynamically favored over heteroaggregation.

Abstract: Various types of edge seals for protecting electro-optic displays against environmental contaminants are described. In one type of seal, the electro-optic layer is sandwiched between a backplane and a protective sheet and a sealing material extends between the backplane and the protective sheet. In other seals, the protective sheet is secured to the backplane or to a second protective sheet adjacent the backplane. The electro-optic layer can also be sealed between two layers of adhesive or between one layer of adhesive and the backplane. Other seals make use of flexible tapes extending around the periphery of the display.

Abstract: The image stability of electrophoretic media, comprising a plurality of particles disposed in a fluid and capable of moving through the fluid upon application of an electric field to the medium, can be improved by including in the fluid either a polystyrene or an aggregating diblock copolymer which forms micelle-like structures in the fluid, the diblock copolymer having a first block soluble in the fluid and a second block not swellable by the fluid. In variable transmission electrophoretic media, haze can be reduced by using as the fluid a mixture of a partially hydrogenated aromatic hydrocarbon and a terpene.

Abstract: In electrophoretic media, it is advantageous to use pigment particles having about 1 to 15 per cent by weight of a polymer chemically bonded to, or cross-linked around, the pigment particles. The polymer desirably has a branched chain structure with side chains extending from a main chain. Charged or chargeable groups can be incorporated into the polymer or can be bonded to the particles separately from the polymer. The polymer-coated particles can be prepared by first attaching a polymerizable or polymerization-initiating group to the particle and then reacting the particle with one or more polymerizable monomers or oligomers.

Abstract: An electro-optic display comprises, in order, a backplane comprising a plurality of pixel electrodes; a layer of a solid electro-optic medium; a main adhesive layer; and at least one of a light-transmissive protective layer and a light-transmissive electrically-conductive layer. The electro-optic layer may be in direct contact with the backplane or separated therefrom by a thin auxiliary layer of adhesive. The main adhesive layer may be colored to provide a color filter array. An inverted front plane laminate useful in forming such a display comprises the same layers except that the backplane is replaced by a release sheet. The display combines good low temperature performance and good resolution at higher temperatures.

Abstract: A first electro-optic display comprises first and second substrates, and an adhesive layer and a layer of electro-optic material disposed between the first and second substrates, the adhesive layer comprising a mixture of a polymeric adhesive material and a hydroxyl containing polymer having a number average molecular weight not greater than about 5000. A second electro-optic display is similar to the first but has an adhesive layer comprising a thermally-activated cross-linking agent to reduce void growth when the display is subjected to temperature changes.

Abstract: An electrophoretic display comprises an electrophoretic medium having a plurality of charged particles suspended in a suspending fluid, and two electrodes disposed on opposed sides of the electrophoretic medium. At least one of the electrodes is light-transmissive and forming a viewing surface. The display has a closed optical state in which the charged particles are spread over substantially the entire viewing surface so that light cannot pass through the medium, and an open optical state in which the electrophoretic particles form chains extending between the electrodes so that light can pass through the electrophoretic medium. Insulating layers are disposed between the electrodes and the electrophoretic medium. Similarly electrophoretic displays are provided equipped with color filter arrays or reflectors.

Abstract: Various improvements are provided in gas-based electrophoretic displays, including (a) the use of water getters to remove water from the gas; (b) the use of electron accepting or donating gases; (c) the use of electrophoretic polymer particles having high glass transition temperatures; (d) lateral movement of electrophoretic particles within the display; and (e) the use of variable thickness coatings on electrodes to provide for gray scale.

Abstract: An encapsulation material, intended for use in encapsulated electrophoretic displays, comprises the coacervation product of a polyanionic polymer having a vinyl main chain and a plurality of anionic groups bonded to the main chain, with a cationic or zwitterionic water-soluble polymer capable of forming an immiscible second phase on contact with the polyanionic polymer.

Abstract: An electro-optic display comprises first and second substrates and a lamination adhesive layer and a layer of an electro-optic material disposed between the first and second substrates, the lamination adhesive layer having a thickness of from about 14 to about 25 ?m.

Abstract: An electrophoretic display comprises an electrophoretic medium having a plurality of charged particles suspended in a suspending fluid, and two electrodes disposed on opposed sides of the electrophoretic medium. At least one of the electrodes is light-transmissive and forming a viewing surface. The display has a closed optical state in which the charged particles are spread over substantially the entire viewing surface so that light cannot pass through the medium, and an open optical state in which the electrophoretic particles form chains extending between the electrodes so that light can pass through the electrophoretic medium. Insulating layers are disposed between the electrodes and the electrophoretic medium. Similarly electrophoretic displays are provided equipped with color filter arrays or reflectors.

Abstract: Copper chromite particles can advantageously be used as black particles in electrophoretic media and displays. Preferably, the copper chromite particles are coated with a silica coating and a polymer coating.

Abstract: A two-phase electrophoretic medium comprises a continuous phase and a discontinuous phase. The discontinuous phase comprises a plurality of droplets, each of which comprises a suspending fluid and at least one particle disposed within the suspending fluid and capable of moving through the fluid upon application of an electric field to the electrophoretic medium. The continuous phase surrounds and encapsulates the discontinuous phase. To reduce the humidity sensitivity of the medium, a non-ionizable or crystalline polymer may be used as the continuous phase.

Abstract: An encapsulation material, intended for use in encapsulated electrophoretic displays, comprises the coacervation product of a polyanionic polymer having a vinyl main chain and a plurality of anionic groups bonded to the main chain, with a cationic or zwitterionic water-soluble polymer capable of forming an immiscible second phase on contact with the polyanionic polymer.

Abstract: The invention provides materials and methods (including driving methods) for reducing the effects of remnant voltages in electro-optic displays.

Abstract: A first electrophoretic medium comprises an electrically charged particle suspended in a suspending fluid, the particle having a polymeric shell having repeating units derived from at least one monomer the homopolymer of which is incompatible with the suspending fluid. A second, similar electrophoretic medium comprises a suspending fluid, and first and second types of electrically charged particle suspended in the suspending fluid, the two types of particle having differing optical characteristics but both having polymeric shells. The polymeric shells are arranged such that homoaggregation of the two types of particles is thermodynamically favored over heteroaggregation.