Abstract: A method and an apparatus for measuring reflectivity, charge and/or particle mobility of electrophoretic display mediums and particles are described. The apparatus for evaluating characteristics of an electrophoretic display medium, comprising a cell for containing the electrophoretic display medium, located between conductive substrates, a voltage application unit associated with the cell, an electrometer to measure transient current, and a densitometer to measure reflectance.

Abstract: A method of making a gyricon display device, and a method of determining a monopole charge and a dipole charge of beads in a gyricon display device, is set forth. In the methods, a rectangular waveform switching voltage is applied to the gyricon display device and the reflectance of the display device is measured in order to determine the dipole charge based upon the measured reflectance, and a triangular waveform switching voltage is applied to the gyricon display device and current of the display device is measured to determine the monopole charge based upon the measured current.

Abstract: A method of displaying an image in an electrophoretic display device having at least one display layer including a multiplicity of individual reservoirs containing a display fluid between conductive substrates, wherein the display fluid comprises at least two sets of particles in a liquid medium, the at two sets of particles each exhibiting a different color, wherein a first set of particles and a second set of particles have a same charge polarity and the first set of particles has a higher average charge than the second set of particles, includes applying an electric field to selected ones of the multiplicity of reservoirs to effect movement of one or more of the differently colored sets of particles in the display fluid therein to display a desired color derived from among the sets of differently colored particles, wherein the applying to display a color of the second set of particles involves pulsing an electric field through the conductive substrates for a time sufficient to attract the first set of part

Abstract: Toner particles and a dry-powder electrophoretic display employing such particles are disclosed herein. The toner particles adapted for a dry-powder electrophoretic display comprise emulsion/aggregation particles having a negative charge. At least a portion of the toner particles include a surface coating, comprising a methacrylate polymer, disposed on the surface of the toner particles to impart a positive charge to a set of toner particles. The emulsion/aggregation toner particles have a particle size generally less than about 10 micrometers that allows for improved image quality as compared to conventional toners utilized in dry-powder electrophoretic displays.

Abstract: Exemplary electrophoretic ink capsules for electrophoretic displays, and methods for making the exemplary electrophoretic ink capsules are disclosed. In various embodiments, the electrophoretic ink capsules can include triboelectrically charged electrophoretic particles having higher electrical conductivity than conventionally charged electrophoretic particles allowing fabrication of electrophoretic displays with lower switching fields and faster response times.

Abstract: Toner particles and a dry-powder electrophoretic display employing such particles are disclosed herein. The toner particles adapted for a dry-powder electrophoretic display comprise emulsion/aggregation particles having a negative charge. At least a portion of the toner particles include a surface coating, comprising a methacrylate polymer, disposed on the surface of the toner particles to impart a positive charge to a set of toner particles. The emulsion/aggregation toner particles have a particle size generally less than about 10 micrometers that allows for improved image quality as compared to conventional toners utilized in dry-powder electrophoretic displays.

Abstract: Disclosed is a technique for producing bichromal balls that are adapted for use in high temperature applications. The bichromal balls find particular application in signs and display devices that can be used in environments in which the temperature exceeds 40° C.

Abstract: An electrophoretic display medium includes at least one set of colored particles in a dielectric fluid, wherein the dielectric fluid is a silicone fluid, and wherein the display medium has an electrical conductivity of about 10?11 to about 10?15 S/m. The display medium is included in an electrophoretic display device by including the medium in a multiplicity of individual reservoirs of a display layer or layers that is located between conductive substrates.

Abstract: Toner particles and a dry-powder electrophoretic display employing such particles are disclosed herein. The toner particles adapted for a dry-powder electrophoretic display comprise emulsion/aggregation particles having a negative charge. At least a portion of the toner particles include a surface coating, comprising a methacrylate polymer, disposed on the surface of the toner particles to impart a positive charge to a set of toner particles. The emulsion/aggregation toner particles have a particle size generally less than about 10 micrometers that allows for improved image quality as compared to conventional toners utilized in dry-powder electrophoretic displays.

Abstract: An electrophoretic display medium includes one or more set of colored particles in a dielectric fluid, wherein the display medium has an electrical conductivity of about 10?11 to about 10?15 S/m, and wherein at least one of the one or more set of particles include crosslinked emulsion aggregation polymer particles. The display medium is included in an electrophoretic display device by including the medium in a multiplicity of individual reservoirs of a display layer or layers that is located between conductive substrates.

Abstract: An electrophoretic display includes one or more set of colored particles in a dielectric fluid, wherein at least one of the one or more set of particles comprise particles having a cationic coating thereon imparting a substantially uniform positive charge to the particles. The display medium is included in an electrophoretic display device by including the medium in a multiplicity of individual reservoirs of a display layer or layers that is located between conductive substrates.

Abstract: An electrophoretic display medium includes one or more set of colored particles in a dielectric fluid, and wherein at least one of the one or more set of particles are particles having thereon at least one polyelectrolyte coating. The display medium is included in an electrophoretic display device by including the medium in a multiplicity of individual reservoirs of a display layer or layers that is located between conductive substrates.

Abstract: An electrophoretic display medium includes one or more set of colored particles in a dielectric fluid, wherein at least one of the one or more set of particles are particles having acid functionality imparting a substantially uniform negative charge to the particles. The display medium is included in an electrophoretic display device by including the medium in a multiplicity of individual reservoirs of a display layer or layers that is located between conductive substrates.

Abstract: Compositions of encapsulated triboelectrically charged particles and methods for making them using a spinning disc process are disclosed. The methods can be used to make charged pigment particles embedded in a neutral polymer matrix. The polymer matrix keeps oppositely charged pigment particle from agglomerating. The particles can be used for electrophoretic displays.

Abstract: An electrophoretic display device includes a display layer comprised of a multiplicity of individual reservoirs containing a display medium over a conductive substrate, wherein the display medium comprises one or more set of colored particles dispersed in a dielectric fluid, the display medium having an electrical conductivity of about 1031 11 to about 10?15 S/m. The device further includes either or both a color filter layer over the display layer, wherein the color filter layer comprises each of a red tinted transparent portion, a blue tinted transparent portion and a green tinted transparent portion, and a dark colored light absorptive backplane under the display layer.

Abstract: An electrophoretic display medium includes one or more set of colored particles in a dielectric fluid, wherein at least one of the one or more set of particles comprise colored particles having attached to an external surface thereof surface treated additive particles. The display medium is included in an electrophoretic display device by including the medium in a multiplicity of individual reservoirs of a display layer or layers that is located between conductive substrates.

Abstract: Compositions of encapsulated triboelectrically charged particles and methods for making them using a spinning disc process are disclosed. The methods can be used to make charged pigment particles embedded in a neutral polymer matrix. The polymer matrix keeps oppositely charged pigment particle from agglomerating. The particles can be used for electrophoretic displays.

Abstract: An electrophoretic display device includes a display layer of a multiplicity of individual microcapsules containing a display medium therein and conductive substrates, at least one of the conductive substrates being transparent, wherein the display layer is located in between the conductive substrates, and wherein the display medium includes one or more set of colored particles in a dielectric fluid and has an electric conductivity of about 10?11 to about 10?15 S/m. The microcapsules may be made by encapsulating the display medium in the wall forming material of the microcapsules, and for example a complex coacervation process may be used.

Abstract: A display medium for an electrophoretic display device includes a liquid system, at least one thermally reversible gelling agent, and at least one set of particles exhibiting a color. Inclusion of the gelling agent enables an image formed in the display device at an elevated temperature of about or above the melting point of the gelling agent to be fixed in a gel state, e.g., at temperature of about or below a gel point of the gelling agent. The image thus has stability, even in the absence of an applied electrophoretic field.

Abstract: An electrophoretic display device includes a multiplicity of individual reservoirs containing a display medium between conductive substrates, at least one of which is transparent, wherein the display medium includes one or more set of colored particles in a dielectric fluid, and wherein the multiplicity of individual reservoirs are mesh openings in a fabric mesh whose fibers or filaments segregate the reservoirs.