Abstract: An electrophotographic image forming apparatus and a developing method thereof are provided. The electrophotographic image forming apparatus includes an image carrier body on which an electrostatic latent image is formed, a developing roller which faces the image carrier body and supplies toner to the electrostatic latent image formed on the image carrier body, and an anti-toner-dispersion element which faces an outer circumferential surface of the image carrier body between an exposing section where the electrostatic latent image is formed and a developing section where the electrostatic latent image is developed by the developing roller. A collection bias is applied to the anti-toner-dispersion element to collect dispersed toner from the developing roller.

Abstract: An electrophotographic image forming device is provided which includes an image holder on which an electrostatic latent image is formed. A magnetic roller has a magnetic brush including nonmagnetic toner and a magnetic carrier using a magnetic force. Donor rollers are provided which have toner layers that are received from the magnetic roller on an outer circumference of each of the donor rollers. The donor rollers are located opposite to the image holder to develop the toner onto the electrostatic latent image.

Abstract: A hybrid type developing apparatus and method forms a magnetic brush of non-magnetic toner and a magnetic carrier on a circumference of a magnetic roller forms a uniform toner layer on the circumference of a donor roller using only toner from the magnetic roller, and develops an electrostatic latent image on an image receptor. The hybrid type developing apparatus includes: a plurality of electrodes on the circumference of the donor roller; first and second brush electrodes in an upstream area and a downstream area, respectively, of the donor roller facing the magnetic roller with respect to a direction of rotation; and a bias applying device for applying a recovery bias to the first brush electrode to remove toner from the donor roller and a supply bias to the second brush electrode to supply toner from the magnetic roller to the donor roller.

Abstract: An electrophotographic image forming apparatus and a developing method thereof are provided. The electrophotographic image forming apparatus includes an image carrier body on which an electrostatic latent image is formed, a developing roller which faces the image carrier body and supplies toner to the electrostatic latent image formed on the image carrier body, and an anti-toner-dispersion element which faces an outer circumferential surface of the image carrier body between an exposing section where the electrostatic latent image is formed and a developing section where the electrostatic latent image is developed by the developing roller. A collection bias is applied to the anti-toner-dispersion element to collect dispersed toner from the developing roller.

Abstract: There are provided a hybrid type developing apparatus and method.

Abstract: An electrophotographic image forming apparatus includes: an image receptor on which an electrostatic latent image is formed; a magnetic roller for forming a magnetic brush having a non-magnetic toner and a magnetic carrier by magnetic force; a donor roller facing the image receptor and receiving a toner from the magnetic roller to form a toner layer on an outer circumference thereof; bias applying device for applying a bias voltage to the donor roller to develop the electrostatic latent image by supplying the toner from the toner layer; and toner removing device which contacts the donor roller and removes at least a portion of the toner layer from a surface of the donor roller after developing. A method of developing the latent image on the image receptor is provided by the apparatus.

Abstract: A hybrid type developing apparatus of an electrophotographic image forming apparatus includes: an image receptor on which an electrostatic latent image is formed; a magnetic roller for forming a magnetic brush of non-magnetic toner and magnetic carrier by using magnetic force; a donor roller which faces the image receptor and has a circumference for supporting a toner layer formed by receiving toner from the magnetic roller; a bias voltage applying device for applying a development bias voltage to the donor roller to develop toner of the toner layer to the electrostatic latent image; an electrode positioned at an upstream side at a point closest and most adjacent position between the donor roller and the image receptor and at a downstream side at a point closest and most adjacent position between the donor roller and the magnetic roller and an applied bias voltage of weakening adhesive force of the toner layer to the donor roller and cohesive force of toner to each other.

Abstract: An electrophotographic image forming apparatus is provided which includes a first developing unit which forms a monochrome image in a two-component development method and includes a photosensitive medium on which an electrostatic latent image is formed by a first exposure unit. Additionally, a plurality of second developing units are provided which form a color image in a one-component development method and include a photosensitive medium on which an electrostatic latent image is formed by a second exposure unit. A control unit generates control signals to independently control the operations of the first and second exposure units and the first and second developing units.

Abstract: A liquid developer capable of preventing each of the disadvantages of uneven development density caused by uneven distribution of colored particles, poor transfer due to an insufficient amount of the liquid, and poor fixing due to an excess amount of the liquid, without complicating handling with the generation of volatile gas. Present on the surface of toner particles to be dispersed in a carrier liquid made of dimethyl silicone are a silicone group of one-end methacryloxy-modified silicone and a basic group. The silicone group prevents agglutination of the toner particles with each other. The silicone group functions as an affinity group and provides the toner particles with an affinity to the carrier liquid. Thus, it becomes possible to disperse the toner particles uniformly in the carrier liquid. Besides, the basic group on the surface of toner particles allows the toner particles to ensure the desired charge amount.

Abstract: Provided is an image forming device performing hybrid development that uses magnetic carriers and nonmagnetic carriers. An electrical potential of a non-image portion on an image holder and an electrical potential of a direct current component of a developing bias voltage applied to a developing roller are determined so that a difference between the electrical potentials are less than or equal to a value at which a developing rate of the non-image portion is saturated.

Abstract: An electrophotographic image forming device is provided which includes an image holder on which an electrostatic latent image is formed. A magnetic roller has a magnetic brush including nonmagnetic toner and a magnetic carrier using a magnetic force. Donor rollers are provided which have toner layers that are received from the magnetic roller on an outer circumference of each of the donor rollers. The donor rollers are located opposite to the image holder to develop the toner onto the electrostatic latent image.

Abstract: A developing device for developing a latent image formed on an image carrier with a developing liquid includes a liquid storing section for storing the liquid including a developing substance and a carrier liquid. A developer carrier deposits the liquid fed from the liquid storing section thereon. A float type liquid level sensor senses a liquid level in the liquid storing section. The liquid level sensor includes a magnetic force generating member for generating a magnetic force, a magnetic force sensing device for sensing the magnetic force, and floats movable up and down in accordance with the liquid level in the liquid storing section. A distance between the magnetic force generating member and the magnetic force sensing device varies in accordance with the movement of the floats, allowing the liquid level to be determined on the basis of the output of the magnetic force sensing device.

Abstract: A developing device for developing a latent image formed on an image carrier with a developing liquid includes a liquid storing section for storing the liquid consisting of a developing substance and a carrier liquid. A developer carrier deposits the liquid fed from the liquid storing section thereon. A float type liquid level sensor senses a liquid level in the liquid storing section. The liquid level sensor includes a magnetic force generating member for generating a magnetic force, a magnetic force sensing device for sensing the magnetic force, and floats movable up and down in accordance with the liquid level in the liquid storing section. A distance between the magnetic force generating member and the magnetic force sensing device varies in accordance with the movement of the floats, allowing the liquid level to be determined on the basis of the output of the magnetic force sensing device. An image forming apparatus including the developing device is also disclosed.

Abstract: A liquid developer which includes an insulating liquid, and toner fine particles containing a coloring agent and a toner resin. In the liquid developer, its electric capacitance does not significantly vary in an electric circuit where an electrical double-layer capacitor and an electronic resistance corresponding to a velocity of an electron exchange during an electrode reaction are connected in parallel, and a resistance corresponding to an electric conductivity of the insulating liquid is connected in series. The coloring agent has a coating layer so as to maintain distances between the toner fine particles. The insulating liquid has a viscosity of 0.5 mPa·s to 1000 mPa·s, a specific resistance of 1×1012 ?cm or more, and a surface tension of 30 dyn/cm or less, and may be a nonvolatile liquid having a boiling point of 100° C. or higher.

Abstract: A method for developing a latent image formed on an image carrier with a developing liquid includes storing a liquid consisting of a developing substance and a carrier liquid developing and sensing the liquid fed from the liquid storing section thereon and sensing a liquid level in the liquid storing section using a liquid level sensor. The liquid level sensor includes a magnetic force generating member for generating a magnetic force, a magnetic force sensing device for sensing the magnetic force, and floats movable up and down in accordance with the liquid level in the liquid storing section. A distance between the magnetic force generating member and the magnetic force sensing device varies in accordance with the movement of the floats, allowing the liquid level to be determined on the basis of the output of the magnetic force sensing device. An image forming method including a developing device is also disclosed.

Abstract: A liquid developer capable of preventing each of the disadvantages of uneven development density caused by uneven distribution of colored particles, poor transfer due to an insufficient amount of the liquid, and poor fixing due to an excess amount of the liquid, without complicating handling with the generation of volatile gas. Present on the surface of toner particles to be dispersed in a carrier liquid made of dimethyl silicone are a silicone group of one-end methacryloxy-modified silicone and a basic group. The silicone group prevents agglutination of the toner particles with each other. The silicone group functions as an affinity group and provides the toner particles with an affinity to the carrier liquid. Thus, it becomes possible to disperse the toner particles uniformly in the carrier liquid. Besides, the basic group on the surface of toner particles allows the toner particles to ensure the desired charge amount.

Abstract: A developing device for developing a latent image formed on an image carrier with a developing liquid includes a liquid storing section for storing the liquid consisting of a developing substance and a carrier liquid. A developer carrier deposits the liquid fed from the liquid storing section thereon. A float type liquid level sensor senses a liquid level in the liquid storing section. The liquid level sensor includes a magnetic force generating member for generating a magnetic force, a magnetic force sensing device for sensing the magnetic force, and floats movable up and down in accordance with the liquid level in the liquid storing section. A distance between the magnetic force generating member and the magnetic force sensing device varies in accordance with the movement of the floats, allowing the liquid level to be determined on the basis of the output of the magnetic force sensing device. An image forming apparatus including the developing device is also disclosed.

Abstract: A developing device for developing a latent image formed on an image carrier with a developing liquid includes a liquid storing section for storing the liquid including a developing substance and a carrier liquid. A developer carrier deposits the liquid fed from the liquid storing section thereon. A float type liquid level sensor senses a liquid level in the liquid storing section. The liquid level sensor includes a magnetic force generating member, a magnetic force sensing device, and floats movable up and down in accordance with the liquid level in the liquid storing section. A distance between the magnetic force generating member and the magnetic force sensing device varies in accordance with the movement of the floats, allowing the liquid level to be determined based on the output of the magnetic force sensing device. An image forming apparatus may include the developing device.

Abstract: A liquid developer which includes an insulating liquid, and toner fine particles containing a coloring agent and a toner resin. In the liquid developer, its electric capacitance does not significantly vary in an electric circuit where an electrical double-layer capacitor and an electronic resistance corresponding to a velocity of an electron exchange during an electrode reaction are connected in parallel, and a resistance corresponding to an electric conductivity of the insulating liquid is connected in series. The coloring agent has a coating layer so as to maintain distances between the toner fine particles. The insulating liquid has a viscosity of 0.5 mPa.s to 1000 mPa.s, a specific resistance of 1×1012 &OHgr;cm or more, and a surface tension of 30 dyn/cm or less, and may be a nonvolatile liquid having a boiling point of 100° C. or higher.

Abstract: A method and system for forming electrophotographic images by forming on a transfer belt color toner images of, e.g., the colors of transparent, yellow, magenta, cyan and black in that order from the side of the belt. When the toner images are brought into contact under pressure with, and then transferred to, a recording medium, e.g. a copy sheet, the image on the sheet is obtained with the order of the layers reversed with the transparent toner layer as the uppermost. With the use of transparent toners having relatively large particle size to cover a plurality of underlying color toner layers formed beforehand, the efficiency in image fixing is considerably improved. In addition, by using UV curing resin as the carrier and by forming a film from the carrier itself through the curing steps by UV beam irradiation, the image fixing and surface glossiness are much improved in the electrophotographic color image formation.