Abstract: A developing device includes first and second magnet members respectively including first and second transfer magnetic poles that have different polarities, that generate a magnetic force for transferring a developer from a first developer-transporting member to a second developer-transporting member, and that are located at positions where the developer-transporting members come close to each other, wherein (B1×B2)/L2 is less than about 400 where L represents a distance (mm) between an outer peripheral surface portion of the first developer-transporting member, the portion facing the first transfer magnetic pole, and an outer peripheral surface portion of the second developer-transporting member, the portion facing the second transfer magnetic pole, and B1 and B2 (mT) respectively represent maximum magnetic flux densities of the first and second transfer magnetic poles in a normal line direction on outer peripheral surfaces of the first and second developer-transporting members.

Abstract: A developing device includes: a developing housing in which a developer is to be contained; a first developer carrier that is placed opposedly to an image carrier which is rotated while a latent image is formed on a surface of the image carrier, that is supported by the developing housing, and that is rotated while holding the developer on a surface of the first developer carrier; a second developer carrier that is supported movably with respect to the developing housing, that is opposed to the image carrier on an upstream or downstream side of the first developer carrier in a rotation direction of the image carrier, and that is rotated while holding the developer on a surface of the second developer carrier; and a coupling defined herein.

Abstract: An image forming apparatus includes a plurality of developing devices, a voltage generating part to generate a developing voltage, first switching parts to supply the voltage generated in the voltage generating part to a predetermined developing device out of the plurality of developing devices, a second switching part to selectively supply the developing voltage generated in the voltage generating part to the first switching parts, and a controller to control the first switching parts and the second switching part.

Abstract: A development device configured to develop a latent image with developer including toner and carrier includes a development roller configured to carry the developer. The development roller includes a stationary magnet-fixing member, a plurality of magnets fixed to an interior of the stationary magnet-fixing member to form a plurality of magnetic poles, and a cylindrical rotatable sleeve roller configured to revolve coaxially around the exterior of the magnet-fixing member. Magnetic force distribution of a portion of the plurality of magnetic poles is varied in an axial direction of the development roller at positions corresponding to an image forming area in the axial direction of the development roller, enabling the development device to transport and agitate the developer.

Abstract: A developing apparatus usable with an image forming apparatus includes a developer carrier includes a plurality of magnetic poles and a case to rotatably support the developer carrier, the case storing developer is supplied to the developer carrier, and a magnetic pole changing apparatus disposed at an end of the developer carrier to change a position of the plurality of magnetic poles with respect to the case.

Abstract: A developing device configured to form toner cloud without making toner particles adhere to the electrostatic transport substrate having electrodes. By applying periodical voltages to electrodes, electrically charged toner particles float on the electrostatic transport substrate. Also, a rotatable toner transporter designed to carry toner particles floating on the electrostatic transport substrate. Also, a two-component developer bearer including a sleeve with magnets on which the two-component developer is borne. The two-component developer borne on the sleeve is sent to the toner transporter by rotation of the sleeve. There, toner particles are transported to the toner transporter because of the electric bias applied between the two-component developer bearer and the toner transporter. Toner particles electrically floating on the toner transporter are sent to the photoconductor for development.

Abstract: A compact development apparatus using a two-component developer and an image forming apparatus wherein carrier deterioration is prevented to ensure formation of a high-quality image for a long time. The development apparatus uses the developer made up of a mixture of toner, carrier, and opposite polarity particles to be charged oppositely to the toner wherein the opposite polarity particles contain the particles having a relative dielectric constant of 6.7 or more.

Abstract: An image forming system includes an image forming apparatus with attach/detach sections to/from which a developer container is attachable/detachable and an image bearing body. A driver instructs the apparatus to execute single-color or color-image formation. When a developer container is attached to each attach/detach section, the apparatus is usable as a color image forming apparatus. When a developer container is attached to only one attach/detach section, the apparatus is usable as a single-color image forming apparatus. The apparatus forms an image when the driver instructs the apparatus that is being used as the color image forming apparatus to execute single-color-image formation. The apparatus does not form an image when the driver instructs the apparatus that is being used as the single-color image forming apparatus to execute color-image formation.

Abstract: A color image forming apparatus having a plurality of image forming units with each unit having a developing device and a photoconductive drum with a driven coupling device. A conveying device switches the plurality of image forming units by moving them successively between an image forming position and a waiting position. A photoconductive drum driving device removably engages the driven coupling device of the image forming unit that is positioned in the image forming position and having one driving coupling device for coaxially rotating the photoconductive drum of the image forming unit positioned in the image forming position together as one body. The photoconductive drum positioned in the image forming position is in contact with a transfer device wherein a peripheral velocity of either the photoconductive drum or the transfer device during use is higher than the a peripheral velocity of the other.

Abstract: A solid-state selectably switchable combination cascade/magnetic brush for use in toner deposition or removal devices used in imaging machines of the electrostatic or magnetic type having one or more electro-magnets with one or more electro-magnetic windings and transfer heads placed inside, as well as outside, a photoconductor. Imaging mixture is agitated and conveyed to a transfer head which is exposed and adjacent to a photoconductor thereby eliminating the need for a drum or sleeve as the carrier/deposition agent for the imaging mixture. Transfer heads deposit imaging mixture directly onto a primary development zone with the excess cascading and attracting to a residual development zone and/or reclamation structure.

Abstract: A magnetic toner for developing an electrostatic image has magnetic toner particles containing at least a binder resin and magnetic iron oxide particles. The magnetic iron oxide particles have been surface-treated with an aliphatic alcohol having carbon atoms of from 12 to 300 on the average. The magnetic toner has a weight average particle diameter of 13.5 .mu.m or smaller, and contains magnetic toner particles with particle diameters of 3.17 .mu.m or smaller in an amount not less than 1% by number as number-based percentage determined from number distribution.