Abstract: The present invention provides an image display medium comprising a pair of substrates facing each other; and a particle group comprising two or more types of particles sealed in a space between the substrates, at least one of the two or more types of particles being positively chargeable by an external stimulus and at least one other of the two or more types of particles being negatively chargeable by an external stimulus, and the positively chargeable and negatively chargeable particles having, respectively, colors different from each other, wherein the positively chargeable and negatively chargeable particles have particle size distributions satisfying 0.4<Ds/Dl<0.9. Ds represents the particle size distribution of at least one type of particles charged with one polarity and Dl represents that of at least one other type of particles charged with the other polarity.

Abstract: The present invention provides display device particles that have positive or negative chargeability and have color and are produced using at least a calcium compound, in which a concentration of the calcium compound in the display device particle is 0.05% by weight or less in terms of a calcium element content, a process for producing the display device particles, as well as an image-display medium and an image-forming device each using the display device particles.

Abstract: The present invention provides display device particles that have positive or negative chargeability and have color and are produced using at least a calcium compound, in which a concentration of the calcium compound in the display device particle is 0.05% by weight or less in terms of a calcium element content, a process for producing the display device particles, as well as an image-display medium and an image-forming device each using the display device particles.

Abstract: The present invention provides display device particles that have positive or negative chargeability and have color and are produced using at least a calcium compound, in which a concentration of the calcium compound in the display device particle is 0.05% by weight or less in terms of a calcium element content, a process for producing the display device particles, as well as an image-display medium and an image-forming device each using the display device particles.

Abstract: An image forming method, including forming an unfixed toner image on the surface of paper by an electrophotographic process using a developer containing a toner, and fixing the toner image on the paper, wherein a toner amount of the unfixed toner image is in the range of about 2.0 to 4.5 g/m2 for a toner image formed using a toner of one color, and in the range of about 8.0 to 18 g/m2 for a toner image formed by layering toners of four or more colors, and a bulk density of the toner is in the range of about 0.2 to 0.5 g/cm3.

Abstract: The invention provides particles for a display device having a positively or negatively chargeable property and color, and the particles have an abundance ratio of amorphous particles with a major axis to minor axis length ratio of approximately 1.2 or greater is approximately 5% or less by number.

Abstract: The present invention provides an image display medium including a pair of substrates disposed so as to face each other and first and second particles contained in space between the pair of substrates, wherein the first particles can be positively or negatively charged due to external stimulus and have one color and a particle size distribution in which at least one peak is present on a coarse side of the most frequent particle diameter of the first particles, and the second particles are not charged or can be charged due to the external stimulus to have polarity opposite to that of the first particles and have another color: and an image formation device comprising the image display medium and a generator for generating an electric field between the pair of substrates in accordance with an image to be displayed.

Abstract: A particle for a display device having a positively or negatively chargeable property and a color, the particle for a display device comprising nitrogen atoms in an amount of 0.03 mmol/g to 0.2 mmol/g. This particle for a display device can avoid reduction in image density and density contrast even after repeated rewriting, and thus prevent decrease in uniformity of an image and unevenness in image from occurring.

Abstract: An image forming method, including forming an unfixed toner image on the surface of paper by an electrophotographic process using a developer containing a toner, and fixing the toner image on the paper, wherein a toner amount of the unfixed toner image is in the range of about 2.0 to 4.5 g/m2 for a toner image formed using a toner of one color, and in the range of about 8.0 to 18 g/m2 for a toner image formed by layering toners of four or more colors, and a bulk density of the toner is in the range of about 0.2 to 0.5 g/cm3.

Abstract: The invention provides particles for a display device having a positively or negatively chargeable property and color, and the particles have an abundance ratio of amorphous particles with a major axis to minor axis length ratio of approximately 1.2 or greater is approximately 5% or less by number.

Abstract: The present invention provides an image display medium including a pair of substrates disposed so as to face each other and first and second particles contained in space between the pair of substrates, wherein the first particles can be positively or negatively charged due to external stimulus and have one color and a particle size distribution in which at least one peak is present on a coarse side of the most frequent particle diameter of the first particles, and the second particles are not charged or can be charged due to the external stimulus to have polarity opposite to that of the first particles and have another color: and an image formation device comprising the image display medium and a generator for generating an electric field between the pair of substrates in accordance with an image to be displayed.

Abstract: Particles for a display device including carbon black having a pH of 3.5 or less and having a property of being able to be charged positively or negatively. The particles are produced by at least mixing and stirring an oil phase solution including the carbon black and a compound containing a nitrogen atom, and an aqueous phase solution.

Abstract: The present invention provides an image display medium comprising a pair of substrates facing each other; and a particle group comprising two or more types of particles sealed in a space between the substrates, at least one of the two or more types of particles being positively chargeable by an external stimulus and at least one other of the two or more types of particles being negatively chargeable by an external stimulus, and the positively chargeable and negatively chargeable particles having, respectively, colors different from each other, wherein the positively chargeable and negatively chargeable particles have particle size distributions satisfying 0.4<Ds/Dl<0.9. Ds represents the particle size distribution of at least one type of particles charged with one polarity and Dl represents that of at least one other type of particles charged with the other polarity.

Abstract: The present invention provides display device particles that have positive or negative chargeability and have color and are produced using at least a calcium compound, in which a concentration of the calcium compound in the display device particle is 0.05% by weight or less in terms of a calcium element content, a process for producing the display device particles, as well as an image-display medium and an image-forming device each using the display device particles.

Abstract: An image display medium comprises a display substrate on which an image is displayed and a non-displaying substrate opposing to the substrate, wherein a spacer and black particles and white particles are enclosed between these substrates. The display substrate and non-display substrate each have a transparent electrode, wherein the transparent electrode for the non-display substrate is grounded and the transparent electrode for the display substrate is connected to voltage applying means. As these black particles and white particles, particles for a display device having a weight reduction rate of not more than 0.3% at 100° C. to 240° C. are respectively used.

Abstract: The present invention provides a process for producing display device particles having positive or negative chargeability and having color, including: at least an emulsification step in which calcium carbonate is added as an emulsifying auxiliary to a display device particle-forming composition that contains a colorant and a polymerizable monomer or a resin, wherein the emulsifying auxiliary is calcium carbonate coated with a hydrophilic organic material, an average dispersed particle size of the emulsifying auxiliary present in an aqueous medium ranges from 0.05 to 1 ?m, a variation coefficient of the dispersed particle sizes is 60% or less, and an electric field generating unit is provided to generate an electric field corresponding to the image.

Abstract: An image display medium comprises a display substrate on which an image is displayed and a non-displaying substrate opposing to the substrate, wherein a spacer and black particles and white particles are enclosed between these substrates. The display substrate and non-display substrate each have a transparent electrode, wherein the transparent electrode for the non-display substrate is grounded and the transparent electrode for the display substrate is connected to voltage applying means. As these black particles and white particles, particles for a display device having a weight reduction rate of not more than 0.3% at 100° C. to 240° C. are respectively used.

Abstract: A particle for a display device having a positively or negatively chargeable property and a color, the particle for a display device comprising nitrogen atoms in an amount of 0.03 mmol/g to 0.2 mmol/g. This particle for a display device can avoid reduction in image density and density contrast even after repeated rewriting, and thus prevent decrease in uniformity of an image and unevenness in image from occurring.

Abstract: The present invention discloses an ink composition which includes (1) the first ink containing the first solvent and the first colored particles having an affinity for the first solvent and dispersed in the first solvent and (2) the second ink containing the second solvent and the second colored particles having a color different from that of the first colored particles and having an affinity for the second solvent and dispersed in the second solvent, and which separates into two phases, and a rewritable display medium and methods for displaying images utilizing the ink composition.The ink composition, the rewritable display medium and methods for displaying images provide sharp images with high resolution over time.

Abstract: An optical element comprises a molded body of a composition of a cross-linked macromolecular liquid crystal and a resin. An optical element composed of a macromolecular liquid crystal composition where the granules of the cross-linked macromolecular liquid crystal are dispersed into the resin as a binder is preferable. The element can be made by preparing in advance granules of the cross-linked macromolecular crystal liquid by a physical or chemical crushing manner, dispersing the granules in the binder, and then molding it.