Abstract: The image forming apparatus includes a latent image bearing member; a charging device charging the surface of the latent image bearing member; a latent image forming device forming an electrostatic latent image on the surface of the latent image bearing member; a developing device supplying toner to the electrostatic latent image to form a toner image; a cover film supplying device supplying a cover film to the surface of the latent image bearing member at a cover film supplying position located on an upstream side from the development position so that the toner image is formed on the cover film covering the surface of the latent image bearing member; and a cover film separating device separating the cover film bearing the toner image thereon from the surface of the image bearing member before the cover film bearing the toner image thereon reaches the cover film supplying position.

Abstract: An image forming apparatus includes an image carrier, a charging unit including a charge member that is disposed facing the image carrier across a gap therebetween and charges the image carrier by using electrical discharge caused by applying thereto a voltage including an alternating current component superimposed on a direct current component, a latent image forming unit, a developing unit to supply toner for developing the latent image formed on the image carrier into a toner image and to collect residual toner remaining on the image carrier, a transfer unit, and a toner spreading member to spread toner on the image carrier and disposed upstream from the charging unit in a direction of movement of the image carrier and downstream from the transfer unit in the direction of movement of the image carrier.

Abstract: A transfer residual toner that has not been electrostatically transferred onto a transfer paper P at a transfer nip and remains on a surface of a photosensitive element is temporarily retained by an elastic blade of a toner retaining unit in a mechanical manner before reaching a latent image forming area. When passing through the latent image forming area, the transfer residual toner is returned onto the surface of the photosensitive member at such a timing that writing is not performed by an exposing unit on the surface of the photosensitive element.

Abstract: The image forming apparatus includes a latent image bearing member; a charging device charging the surface of the latent image bearing member; a latent image forming device forming an electrostatic latent image on the surface of the latent image bearing member; a developing device supplying toner to the electrostatic latent image to form a toner image; a cover film supplying device supplying a cover film to the surface of the latent image bearing member at a cover film supplying position located on an upstream side from the development position so that the toner image is formed on the cover film covering the surface of the latent image bearing member; and a cover film separating device separating the cover film bearing the toner image thereon from the surface of the image bearing member before the cover film bearing the toner image thereon reaches the cover film supplying position.

Abstract: An image forming apparatus includes an image carrier, a developing unit, a concentration sensor, a toner supplying unit, a developer supplying unit, an ejector, and a condition detector. The image carrier forms a latent image thereon. The developing unit develops the latent image formed on the image carrier with a two-component image developer including toner particles and carrier particles. The concentration sensor detects a toner ratio in the developing unit. The toner supplying unit supplies fresh toner particles to the developing unit. The developer supplying unit supplies fresh image developer to the developing unit. The ejector ejects the image developer to an outside of the developing unit. The condition detector detects a condition of the image developer used for an image forming operation to determine a supply amount of the image developer to supply to the developing unit. The condition includes a degradation level of the image developer.

Abstract: An image forming apparatus includes an image carrier, a charging unit including a charge member that is disposed facing the image carrier across a gap therebetween and charges the image carrier by using electrical discharge caused by applying thereto a voltage including an alternating current component superimposed on a direct current component, a latent image forming unit, a developing unit to supply toner for developing the latent image formed on the image carrier into a toner image and to collect residual toner remaining on the image carrier, a transfer unit, and a toner spreading member to spread toner on the image carrier and disposed upstream from the charging unit in a direction of movement of the image carrier and downstream from the transfer unit in the direction of movement of the image carrier.

Abstract: A transfer residual toner that has not been electrostatically transferred onto a transfer paper P at a transfer nip and remains on a surface of a photosensitive element is temporarily retained by an elastic blade of a toner retaining unit in a mechanical manner before reaching a latent image forming area. When passing through the latent image forming area, the transfer residual toner is returned onto the surface of the photosensitive member at such a timing that writing is not performed by an exposing unit on the surface of the photosensitive element.

Abstract: A transfer residual toner that has not been electrostatically transferred onto a transfer paper P at a transfer nip and remains on a surface of a photosensitive element is temporarily retained by an elastic blade of a toner retaining unit in a mechanical manner before reaching a latent image forming area. When passing through the latent image forming area, the transfer residual toner is returned onto the surface of the photosensitive member at such a timing that writing is not performed by an exposing unit on the surface of the photosensitive element.

Abstract: A bias voltage-applying unit applies a bias voltage to an insulating toner that includes an electric charge, by making a contact with the insulating toner. A light irradiating unit irradiates the insulating toner with a light. An electric-charge control unit controls an electric charge amount of the insulating toner by causing an optical switch phenomenon in which an electrostatic charge amount of the insulating toner changes, by irradiating the insulating toner with the light using the light irradiating unit while applying the bias voltage to the insulating toner using the bias voltage-applying unit.

Abstract: An image forming apparatus of includes a developing device bifunctioning as a cleaning device for collecting toner grains left on a photoconductive drum after the transfer of a toner image from the drum to a paper sheet or similar image transfer medium. In the event of toner collection, a DC voltage is applied that causes the residual toner to move from the drum toward a developing sleeve. A main-pole magnet generates, at a position where the developing sleeve faces the drum, a magnetic field of between 100 mT and 200 mT in a direction normal to the surface of the sleeve.

Abstract: An image forming apparatus includes an image carrier, a developing unit, a concentration sensor, a toner supplying unit, a developer supplying unit, an ejector, and a condition detector. The image carrier forms a latent image thereon. The developing unit develops the latent image formed on the image carrier with a two-component image developer including toner particles and carrier particles. The concentration sensor detects a toner ratio in the developing unit. The toner supplying unit supplies fresh toner particles to the developing unit. The developer supplying unit supplies fresh image developer to the developing unit. The ejector ejects the image developer to an outside of the developing unit. The condition detector detects a condition of the image developer used for an image forming operation to determine a supply amount of the image developer to supply to the developing unit. The condition includes a degradation level of the image developer.

Abstract: An image forming apparatus includes an image carrier, a charging device configured to uniformly charge a surface of the image carrier with a charging member applied with a bias of a first polarity (e.g. a negative polarity) for charging. A latent image forming device forms a latent image on the surface of the image carrier uniformly charged. A developing device develops a latent image by depositing toner grains of the first polarity on the latent image to thereby form a corresponding toner image. A transferring device forms an electric field between the image carrier and a moving member that serves as a movable contact with the image carrier to thereby transfer the toner image from the surface of the image carrier to the moving member or to a recording member nipped between the image carrier and the moving member. A polarity controlling device sets residual toner to a second polarity (e.g.

Abstract: A developing method of the present invention develops a latent image formed on an image carrier with a two-ingredient type developer, which consists of toner grains and carrier grains retaining the toner grains thereon, deposited on a developer carrier in the form of brush chains. Assume that the brush chains on the developer carrier has a height of h as measured at a zero field point where the magnetic field formed by a main magnet is zero, and that a gap for development that is the shortest distance between the developer carrier and the image carrier is a, then a and h are equal to each other. Image quality is estimated by varying the combination of an angle ? between the gap and the zero field point, the outside diameter of the image carrier and the outside diameter of the developer carrier and the height h. A desirable or an optimum range of the results of estimation are selected to set various conditions.

Abstract: A developing method and apparatus of the present invention develops a latent image formed on an image carrier with a two-ingredient type developer, which consists of toner grain and carrier grains, deposited on a developer carrier in the form of a brush. A distance L between a zero field point at which the magnetic field of a main magnet is zero and the image carrier is 4 mm or smaller.

Abstract: A two-component developer including toner and magnetic carriers is provided. The two-component developer is characterized in that when a development device including a developer bearing member bearing the two-component developer is operated under a development condition of an image forming apparatus using a quasi-photoconductor in which a 10 ?m thick layer of tetrafluoroethylene resin is provided to a conductive material, the number of times of light emission occurring in a magnetic brush formed on the developer bearing member due to partial conduction in the magnetic brush is 10 times or less per second at an observation cross section that is perpendicular relative to a rotation axis of the developer bearing member.

Abstract: An image forming apparatus of the present invention includes a developing device bifunctioning as a cleaning device for collecting toner grains left on a photoconductive drum after the transfer of a toner image from the drum to a paper sheet or similar image transfer medium. In the event of toner collection, a DC voltage is applied that causes the residual toner to move from the drum toward a developing sleeve. A main-pole magnet generates, at a position where the developing sleeve faces the drum, a magnetic field of between 100 mT and 200 mT in a direction normal to the surface of the sleeve.

Abstract: A developing method of the present invention develops a latent image formed on an image carrier with a two-ingredient type developer, which consists of toner grains and carrier grains retaining the toner grains thereon, deposited on a developer carrier in the form of brush chains. Assume that the brush chains on the developer carrier has a height of h as measured at a zero field point where the magnetic field formed by a main magnet is zero, and that a gap for development that is the shortest distance between the developer carrier and the image carrier is a, then a and h are equal to each other. Image quality is estimated by varying the combination of an angle e between the gap and the zero field point, the outside diameter of the image carrier and the outside diameter of the developer carrier and the height h. A desirable or an optimum range of the results of estimation are selected to set various conditions.

Abstract: A transfer residual toner that has not been electrostatically transferred onto a transfer paper P at a transfer nip and remains on a surface of a photosensitive element is temporarily retained by an elastic blade of a toner retaining unit in a mechanical manner before reaching a latent image forming area. When passing through the latent image forming area, the transfer residual toner is returned onto the surface of the photosensitive member at such a timing that writing is not performed by an exposing unit on the surface of the photosensitive element.

Abstract: An image forming apparatus includes an image carrier, a charging device configured to uniformly charge a surface of the image carrier with a charging member applied with a bias of a first polarity (e.g. a negative polarity) for charging. A latent image forming device forms a latent image on the surface of the image carrier uniformly charged. A developing device develops a latent image by depositing toner grains of the first polarity on the latent image to thereby form a corresponding toner image. A transferring device forms an electric field between the image carrier and a moving member that serves as a movable contact with the image carrier to thereby transfer the toner image from the surface of the image carrier to the moving member or to a recording member nipped between the image carrier and the moving member. A polarity controlling device sets residual toner to a second polarity (e.g.

Abstract: A two-component developer including toner and magnetic carriers is provided. The two-component developer is characterized in that when a development device including a developer bearing member bearing the two-component developer is operated under a development condition of an image forming apparatus using a quasi-photoconductor in which a 10 &mgr;m thick layer of tetrafluoroethylene resin is provided to a conductive material, the number of times of light emission occurring in a magnetic brush formed on the developer bearing member due to partial conduction in the magnetic brush is 10 times or less per second at an observation cross section that is perpendicular relative to a rotation axis of the developer bearing member.