Abstract: An apparatus for forming images on at least one surface of a sheet includes a reader for reading image information on documents, a memory for storing image signals output by the reader, and an image forming unit for selectively forming one of: (i) two page toner images corresponding to the image signals of two pages of the documents separately on two image carrying members, and (ii) a single toner image on one of the two image carrying members. A jam detector detects a jammed sheet, and a delivery detector detects delivery of a copied sheet to outside the apparatus. Image signals are eliminated from memory in accordance with a progression of image formation.

Abstract: An apparatus for forming toner images on both sides of a sheet includes a first transfer device which transfers a toner image from a rotatable image forming body onto a rotatable intermediate transfer member or onto the first side of a sheet; a second transfer device which transfers a toner image from the rotatable intermediate transfer member onto the second side of the sheet; and a fixing device which fixes the toner image on the first side of the sheet and the toner image on the second side of the sheet simultaneously. The sheet is conveyed to the first transfer device and to the second transfer device by the rotatable intermediate transfer member, is separated at a separating section from the rotatable intermediate transfer member, and is brought to the fixing device. The second transfer device is located between the first transfer device and the separating section, and a conductive member is located opposite the second transfer device.

Abstract: An apparatus for forming a toner image on both sides of a sheet, includes a photoreceptor on which a first toner image and a second toner image are formed by toner image forming devices; a second image carrying belt onto which the second toner image is transferred from the photoreceptor; a first transferring device to transfer the first toner image from the photoreceptor to a first side of the sheet; a second transferring device to transfer the second toner image from the second image carrying belt to a second side of the sheet; a fixing device having a first fixing roller for fixing the first toner image onto the first side of the sheet and a second fixing roller for fixing the second toner image onto the second side of the sheet, the first fixing roller coming in contact with the second fixing roller so as to form a nip section therebetween; the second image carrying belt having a flat belt surface on which the sheet is conveyed from the photoreceptor toward a separating section at which the sheet is separa

Abstract: An image forming apparatus includes a first image carrier on which a toner image forming device forms a toner image; a second image carrier provided opposite to the first image carrier, onto which the toner image on the first image carrier is transferred; first and second transfer devices for transferring the toner image on the first and second image carriers onto one side and the other side of a transfer material, respectively; and a fixing device for fixing the toner images on both sides of the transfer material transferred respectively by the first and second transfer devices. The fixing device includes first and second fixing members provided opposite to one side and the other side of the transfer material, respectively, wherein the transfer material passes between the first and second fixing members, and first and second sensors are provided for detecting temperature of the first and second fixing members respectively.

Abstract: An image forming apparatus for forming images corresponding to image data of plural pages.

Abstract: An apparatus for forming an image on a sheet member includes a photoreceptor drum on which a first toner image and a second toner image are separately formed; an image carrying belt on which the second toner image is transferred from the photoreceptor drum; a first transfer device to transfer the first toner image from the photoreceptor drum to a first side of the sheet member; a second transfer device to transfer the second toner image from the image carrying belt to the other side of the sheet member; and a cleaner capable of being brought in contact with anal separated from the image carrying belt. The cleaner is brought in contact with the image carrying belt after the first toner image is transferred from the photoreceptor drum to the first side of the sheet member.

Abstract: An image forming apparatus includes: a toner image forming device to form a toner image on a first image carrier; a first transfer device to transfer the toner image on the first image carrier onto a second image carrier provided opposite to the first image carrier to carry a transferred toner image, or to transfer the toner image on the first image carrier onto one side of a transfer material; a second transfer device to transfer the toner image carried on the second image carrier onto the other side of the material; a fixing device to fix at least one of the toner image on the one side of the transfer material and the toner image on the other side of the transfer material; and a control device to control the toner image forming device, the first transfer device and the second transfer device.

Abstract: In an image forming apparatus provided with a photoreceptor on which a obverse toner image is formed, a toner image receiving body on which a reverse toner image is transferred from the photoreceptor, and transfer devices to transfer the obverse image onto one side of a sheet and to transfer the reverse image onto the other side of the sheet. An image forming condition for the reverse image is changed to be different from that for the obverse image.

Abstract: An image forming apparatus has a photoreceptor drum and a toner image receptor for forming toner images on both sides of a transfer sheet.

Abstract: A development apparatus for developing a latent image formed on an image forming body with a developer so as to obtain a toner image. A developer conveyance unit conveys the developer, including a toner, to a development zone, between the developer conveyance unit and the image forming body, from an upstream side of the development zone in a conveyance direction to a downstream side thereof. A plate member having an electrode portion is positioned at the upstream side of the development zone, wherein a downstream end portion of the plate member is positioned in contact with the development zone. A power supply unit applies a first voltage, including a DC component and an AC component, to the developer conveyance unit so that an electric field is generated at the development zone. The power supply unit applies a second voltage, including a DC component, to the electrode portion of the plate member, and the plate member controls the electric field with the second voltage. The development apparatus satisfies: V.

Abstract: A non-contact type of developing device for use in an image forming apparatus having an image forming body, includes a developer conveying body facing the image forming body in which a magnet body having a plurality of magnet poles are attached therein, to convey two-component developer in the form of a developer layer onto a developing area and a control electrode provided at the developing area or upstream of the developing area. The control electrode has an electrically insulating member which is in contact with or close to the developing layer, and an electrode to which a voltage is applicable is attached to the insulating member. The following condition is satisfied: ##EQU1## where D.sub.T represents a number of toner layers on the assumption that the toner particles passing through the developing area are filled most densely, D.sub.WS represents a conveying amount (mg/cm.sup.2) of the developer layer at the developing area on the developer conveying body, T.sub.

Abstract: In an magnetic brush charging apparatus, a following relation is satisfied, .rho..ltoreq.M/H.ltoreq.1.6 .rho., wherein H is a minimum gap distance (cm) between a cylinder and an image carrying member, .rho. is a density (g/cm.sup.3) of magnetic particles and M is an amount (g/cm.sup.2) of magnetic particles existing in a nip region coming in contact with the image carrying member.

Abstract: An image forming apparatus uses a contact-type charger to charge a photoreceptor. The D.C. current supplied to the charger is measured while the output value of the A.C. voltage is changed within a predetermined range, and the output value of the A.C. voltage is set in accordance with the measurement result.

Abstract: An image forming apparatus such as an electrophotographic copier and an electrophotographic printer. The image forming apparatus includes: a photoreceptor for forming a toner image on its surface; a charger for charging the surface with a bias voltage, including a DC component and a AC component, through a magnetic brush member which is in contact with the surface; a driving unit for moving both of the surface of the photoreceptor and the magnetic brush member in synchronism; a laser unit for imagewisely exposing a predetermined image area of the surface, which is charged by the charger, so that a latent image is formed on the surface; and a discharge lamp for exposing the surface with light so that the surface is discharged.

Abstract: A device for charging a photoreceptor on which a toner image is formed, comprises a rotatable sleeve, at least two magnets disposed in the sleeve so as to attract magnetic particles in a form of magnetic brush, and a electric power source to provide the photoreceptor with an electric charge through the magnetic brush. One of the magnets is disposed upstream of the closest point between the photoreceptor and the sleeve, and the other magnet is disposed downstream of the closest point.

Abstract: An image forming machine has a charging roller on which magnetic particles are supplied to form a magnetic brush and an image forming body which is charged under the condition that the magnetic brush on the charging roller is in an alternating electric field. When the distance between a regulating member that regulates an amount of the magnetic particles passing through and the charging roller is defined to be DB and the distance between the image forming body and the charging roller is defined to be DI, an inequality of 0.7 DB.ltoreq.DI.ltoreq.1.0 DB is satisfied. More preferably, DB is in the relation of 0.2.ltoreq.DB.ltoreq.1.0 in mm.

Abstract: An image forming machine such as a copier or a printer for developing a latent image on a photoreceptor with toner. The image forming machine includes a sleeve for charging the photoreceptor; magnetic particles for forming a magnetic brush on a surface of the sleeve; a driver for driving the sleeve so that the magnetic brush is moved; and a power applying circuit for applying an alternating current between 20 and 500 .mu.A/cm on to a charging area between the sleeve and the photoreceptor; in which the sleeve is located in the vicinity of the photoreceptor so that the magnetic brush is in contact with the surface of the photoreceptor.

Abstract: A method of developing an electrostatic latent image wherein an electrostatic latent image with a negative polarity is formed on an organic photoreceptor and developed with a toner bearing a positive electric charge. The toner used to develop the latent image includes a binder resin, a coloring agent, silica, zinc stearate, and at least one oxide selected from hydrophobic aluminum oxide and hydrophobic titanium oxide. This method of developing the electrostatic latent image produces an image having a higher maximum image density.

Abstract: A carrier for developing electrostatic images is disclosed. The carrier comprises a core and a resin coating layer provided thereon. The coating layer comprises two kinds of polymer resin, one of them is a vinylidene fluoride/tetrafluoroethylene copolymer, and the other one is a polymer containing, as a monomer component, an acrylate which has a group substituted with at least one fluorine atom. The carrier is improved in its durability and electrostatic properties. A high density images without fog are obtained when electrophotographic images are developed with the developer containing this carrier.

Abstract: In a process for forming an image comprising;(i) forming a latent image on a latent image bearing member comprising an organic photoconductive photosensitive member;(ii) forming a magnetic brush with a two-component developer comprising a toner and a carrier on a developer carrying member arranged as opposed to said latent image bearing member; and(iii) developing said latent image by brushing it with said magnetic brush in developing region;the improvement wherein said latent image bearing member and said developer carrying member move in the same direction in the developing region, and the ratio V.sub.S /V.sub.P of the linear velocity of said developer carrying member V.sub.S to the linear velocity of said latent image bearing member V.sub.P is within the range of 1.9.ltoreq.V.sub.S /V.sub.P .ltoreq.4.According to this process, an image which is free from fog, yet high in image density and stable for repeated copying can be obtained.