Abstract: A image forming apparatus having a developer controlling apparatus for a developing roller is provided to uniformly control an amount of developer deposited on the developing roller and a developer controlling method thereof. The apparatus includes a sensing part having a first sensor which senses a conductivity of a liquid developer and a second sensor which senses a density of the liquid developer. A control part controls a voltage applied to the developing roller and/or a deposit roller according to the conductivity and the density sensed by the sensing part.

Abstract: A composition for an overcoat layer suitable for use in an organophotoreceptor for liquid toner, an organophotoreceptor manufactured by employing the composition and an electrophotographic imaging apparatus containing the organophotoreceptor. Since the organophotoreceptor can maintain higher charge potential and low residual or discharge potential, the lifetime of the organophotoreceptor can be extended. Also, since the organophotoreceptor has good solvent resistance and abrasion resistance, it can be advantageously used for liquid toner.

Abstract: A developer cartridge for a wet-type image forming apparatus comprises a cartridge body in which developer is stored. The cartridge body has a supply hole formed thereon to supply the developer in the cartridge to the image forming apparatus. A filter is disposed in the cartridge body to improve the dispersion of the developer, and to filter sludge of the developer before the developer flows into the supply hole.

Abstract: A test apparatus to evaluate the electrical properties of a liquid toner in which a printing quality of the liquid toner may be predicted by evaluating the electrical properties of the liquid toner without performing printing. The test apparatus to evaluate the electrical properties of a liquid toner includes a roller, a conductive flat panel positioned below the roller to move a predetermined distance in contact with the roller, a power supply device applying a voltage to the roller and the conductive flat panel, and a voltage tester provided at the rear of the roller to move together with the roller, testing a voltage of the liquid toner arranged on the conductive flat panel.

Abstract: A composition for a charge generating layer of a positively-charged electrophotographic organophotoreceptor and a method of manufacturing same. The charge generating layer composition for the positively-charged electrophotographic organophotoreceptor, which has a charge transport layer and a charge generating layer sequentially coated on a conductive support, includes a charge generating material, a binder, and an organic solvent containing an alcoholic solvent and an acetate solvent in a ratio from 1:9 to 5:5 by weight.

Abstract: A liquid toner composition and a preparation method utilize a colorant, an organosol, a charge control agent, a carrier liquid, a dispersion assistant agent, and a photoreactive catalyst, in which the dispersion assistant agent is a polymer including an unsaturated functional group to cause photopolymerization in a presence of the photoreactive catalyst, and the photoreactive catalyst produces a free radical through an irradiation of light, and initiates the photopolymerization of the dispersion assistant agent. According to embodiments of the present invention, the toner organosol rarely affects the physical properties required of the liquid toner, and an offset error in a fixing operation is removed, resulting in an improved quality of a printed image.

Abstract: A double-layered positively-charged organic photoreceptor has a charge transport layer with effective adhesion to an electroconductive support and effective resistance against dissolving when in contact with a hydrocarbon-based solvent of a wet developer. Therefore, the double-layered positively-charged organic photoreceptor requires neither anodizing on the electroconductive support nor an additional adhesive layer, and is compatible with wet developing methods. The double-layered positively-charged organic photoreceptor includes: an electroconductive support; a charge transport layer formed on a surface of the electroconductive support and including a charge transport material for transporting holes, a polycarbonate-based first binder resin, and a second binder resin of a polyester copolymer with a biphenylfluorene group; and a charge generating layer formed on the surface of the charge transport layer.

Abstract: A composition forms an overcoat layer of an organophotoreceptor, the composition including polyaminoether and a solvent, and an organophotoreceptor employing the overcoat layer formed from the composition. The polyaminoether is represented by Formula 1: wherein n is an integer from 10 to 400.

Abstract: A liquid ink composition includes a colorant, a charge control agent, an organosol, a carrier liquid, and a storage stabilizer. The storage stabilizer is a metal salt of a metal cation and an organic anion having 15 to 30 carbon atoms. The liquid ink composition is produced by a method of adding the storage stabilizer in an effective amount to improve the dispersibility and storage stability at high temperatures without deteriorating the electrical property and the optical density of the liquid ink composition. The storage stabilizer can be a metal salt of C15 to C30 alkyl carboxylate or a metal salt of a C15 to C30 alkyl sulfonate.

Abstract: A liquid ink composition and a method for producing the same, wherein the liquid ink composition includes a colorant, a charge control agent to regulate electrostatic properties of the colorant, and an organosol to disperse and bind the colorant and the charge control agent. The colorant may be coated with a thermoplastic resin to improve binding with the organosol. By coating the colorant with the thermoplastic resin, the affinity of the colorant for the organosol is facilitated, increasing a size of particles in the liquid ink composition, so that the control of the particles improves the image quality, and micro particles of the carbon black pigment alone do not substantially exist in the printer to prevent printing on a non-image area, thus producing a clear printed image and preventing contamination of other parts in the printer during printing.

Abstract: An overcoat layer composition for an organic photoreceptor and an organic photoreceptor using the overcoat layer composition. The overcoat layer composition has improved electric and mechanical properties to be suitably used for an electrophotographic development system. The overcoat layer composition includes anionic aqueous polyurethane dispersion and a fluorine resin.

Abstract: A composition for an overcoat layer suitable for use in an organophotoreceptor for liquid toner, an organophotoreceptor manufactured by employing the composition and an electrophotographic imaging apparatus containing the organophotoreceptor. Since the organophotoreceptor can maintain higher charge potential and low residual or discharge potential, the lifetime of the organophotoreceptor can be extended. Also, since the organophotoreceptor has good solvent resistance and abrasion resistance, it can be advantageously used for liquid toner.

Abstract: An overcoating composition for an organic photoreceptor and an organic photoreceptor using the overcoating composition. The overcoating composition has improved electrostatic properties and abrasion resistance to be suitably used for an electrophotographic development system. The overcoating composition includes an anionic aqueous polyurethane dispersion.

Abstract: A positively-charged electrophotographic organic photoreceptor includes an electrically conductive support, and a charge transport layer and a charge generating layer sequentially stacked on the electrically conductive support. The charge generating layer is formed by coating a charge generating layer forming composition that includes a fluorene compound, a charge generating material, a binder resin and an organic solvent on the charge transport layer, and drying. The organic photoreceptor has high sensitivity, while suppressing contamination of a charge generating layer during coating, and thicknesses of a charge transport layer and a charge generating layer may be adjusted. Also, the electrostatic properties of the organic photoreceptor, including charge potential and exposure potential, may be easily adjusted.

Abstract: A multi-layered electrophotographic positively charged organic photoconductor includes a conductive substrate, a charge transport layer formed on the conductive substrate, and a charge generating layer formed on the charge transport layer. A composition to form the charge transport layer includes at least one hole transport material, a binder resin and an organic solvent, and a composition to form the charge generating layer includes a charge generating material, a binder resin, an organic solvent and a hole transport material. An organic photoconductor has improved static electrical properties by controlling interfacial conditions of the charge transport layer and the charge generating layer. The charge generating layer may be readily coated on the charge transport layer. In addition, the organic photoconductor has excellent electric properties such as an improved sensitivity and a low discharge voltage.

Abstract: A double-layered positively-charged organic photoreceptor has a charge transport layer with effective adhesion to an electroconductive support and effective resistance against dissolving when in contact with a hydrocarbon-based solvent of a wet developer. Therefore, the double-layered positively-charged organic photoreceptor requires neither anodizing on the electroconductive support nor an additional adhesive layer, and is compatible with wet developing methods. The double-layered positively-charged organic photoreceptor includes: an electroconductive support; a charge transport layer formed on a surface of the electroconductive support and including a charge transport material for transporting holes, a polycarbonate-based first binder resin, and a second binder resin of a polyester copolymer with a biphenylfluorene group; and a charge generating layer formed on the surface of the charge transport layer.

Abstract: An electrophotographic photoreceptor includes a support, an undercoating, and a photosensitive layer, wherein the undercoating includes a charge transport material which is soluble in an organic solvent and a binder resin.

Abstract: A double-layered positively-charged organic photoreceptor t does not suffer from contamination caused by charge transport compounds that dissolve out during coating of a charge generating layer, and in which the charge generating layer and a charge transport layer have suitable interfacial properties for effective charge transfer. The composition that forms a charge transport layer on an electroconductive support contains a first charge transport compound that is soluble in an acetate solvent, a second charge transport compound that is insoluble in an acetate solvent, a binder resin, and an organic solvent. The method of manufacturing the photoreceptor includes: coating a surface of an electroconductive support with the charge transport layer forming composition and drying the surface to form a charge transport layer; and coating a surface of the charge transport layer with a charge generating layer forming composition and drying the surface to form a charge generating layer.

Abstract: A single layered electrophotographic photoreceptor has a photoreceptor layer comprising polyester resin as a binder resin having biphenyl fluorene units in the main chain, and specific phenolic compounds as antioxidants. The electrophotographic photoreceptor according to the present invention enables obtaining a better image by suppressing a decrease in dark decay and charged electric potential due to repeated use and has an extended electrical lifetime.

Abstract: A composition forms an overcoat layer of an organophotoreceptor, the composition including polyaminoether and a solvent, and an organophotoreceptor employing the overcoat layer formed from the composition.