Abstract: An apparatus for forming Y, M, C, and BK color toner images, includes a controller to control an exposure device to conduct a pre-transfer image exposure on the color toner images on the photoreceptor on the basis of recording signals after the final color toner image formation of the Y, M, C, and BK color toner images before transferring the color toner images.

Abstract: An image forming apparatus in which there are integrally provided a process cartridge, composed of an image carrying member in which a latent image is formed, and a developing device and/or a cleaning device. The process cartridge is detachably mountable on the apparatus. A moving device moves the process cartridge from a first position, allowing image forming, to a second position in which the process cartridge can be detached. The moving device outputs a signal indicating that the process cartridge is being moved. There is provided a device to output an instruction signal to a controller which, on receipt of the instruction signal, outputs a drive signal to the moving device to move the process cartridge provided that no signal is input from the moving device.

Abstract: In an image forming apparatus having a detachable process cartridge in which an image carrier on which an electrostatic latent image is formed, and a developing unit which develops the electrostatic latent image so that a toner image can be formed, both integrally formed into one unit. There is provided a developer container including a discharge section which can be inserted into a supply opening of the developing unit, and a container in which a predetermined amount of developer is contained, wherein the developer container is provided to the toner supply opening of the developing unit and the developer is supplied into the developing unit housing when a toner stirring screw of the developing unit is rotated.

Abstract: A method for forming a toner image on a photoreceptor includes charging a photoreceptor to a charged electric potential; exposing the photoreceptor so as to form a reference latent image for each of three colors with an exposure light having a reference image density; developing the three reference latent images with yellow, magenta and cyan developers each of the developers including a carrier and one of the yellow, magenta and cyan color developer so as to form a superimposed three color toner image; detecting a color balance between the superimposed three color toner images by separating reflected light from the superimposed images; and consuming at least one color developer of the yellow, magenta and cyan developers in accordance with a detection result of the color balance so that a new color balance of the superimposed three color toner images will have a desired color balance.

Abstract: A color image forming apparatus includes a housing and a cartridge adapted to be attached to or detached from the housing in a horizontal direction. The cartridge includes a photoreceptor and a plurality of developing devices vertically piled up. Each developing device has an opening to receive toner and a cover to open or close the opening. When the cartridge is detached from the housing in the horizontal direction and is placed in a laid down position thereof, toner can be supplied into the developing devices through the opening which is at the top portion of the laid-down cartridge.

Abstract: An image forming machine such as a copier and a printer for forming a color image on a recording sheet. The image forming machine includes: a photoreceptor for carrying the color image; an image writer such as a laser beam generator for forming a latent image of the color image on a surface of the photoreceptor; plural color developers for developing the latent image with color toners so that a developed color image is formed on the surface of the photoreceptor; a transferer for transferring the developed color image from the photoreceptor to the recording sheet; a cleaner for cleaning a residual portion of the developed color image on the photoreceptor; and a controller for controlling a cleaning operation of the cleaner which starts the cleaning operation after the transferring operation is completed.

Abstract: An image forming apparatus includes a process cartridge that incorporates a photoreceptor and a plurality of developing devices. The process cartridge is provided with a first driving shaft to drive the photoreceptor and a second driving shaft to independently drive the developing devices. When the process cartridge is mounted in the image forming apparatus which includes spaced apart first and second gears, the first and second driving shafts are coupled separately with the spaced apart first and second gears so that driving forces are separately transmitted to the first and second driving shafts. A flywheel is mounted on a third driving shaft that is coupled with the first driving shaft to drive the photoreceptor. Since the developing devices are constructed to receive a large number of different possible loads, the developers are placed in a condition where vibrations are created easily by the driving of the various possible loads.

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 printer or a copying machine for forming a toner image on a photoreceptor includes an image writer, such as a laser beam generator, for forming a latent image on the photoreceptor; a developer for developing the latent image with a developer, which includes a toner and a carrier; a controller for controlling a toner concentration of the developer so that the toner concentration is equalized; a circuit to automatically form a reference toner image on the photoreceptor; a detector for detecting a toner deposition amount of the reference toner image; and a controller circuit for decreasing a toner charge amount of the toner when the toner concentration is equalized and the toner deposition amount of the reference toner image is smaller than a predetermined value.

Abstract: In a color image forming machine including a belt-shaped photoreceptor stretched around a plurality of rollers, and a horizontal portion of the photoreceptor being disposed above and in parallel to face a plurality of developing devices, a charging device and a transfer device are disposed to face the photoreceptor at a common position where the photoreceptor is curved around one roller. A cleaning device is disposed to face the photoreceptor at a position where the photoreceptor is curved around the other roller. The charging device is used as a transfer device by changing supplied voltage or is interchangeable with the transfer device by being either slid or rotated between two positions. The photoreceptor, the developing devices and the cleaning device are integrally formed as a cartridge which is detachably mountable to the machine.

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: An image forming apparatus has a plurality of mixed input thereto including one-sided and two-sided documents, and then copied on sheets which are successively outputted in accordance with the supplied documents. The apparatus has a feeder to feed the documents to a reading station, and a discriminator to discriminate whether each of the documents is a one-sided or a two-sided document. Then the apparatus selectively outputs copied sheets in either a one-sided copy mode, a two-sided copy mode or a mixed copy mode in which one-sided and two-sided copy sheets are outputted in accordance with the mixed one-sided and two-sided documents.

Abstract: The invention provides a photoreceptor belt for forming a latent image on its imaging surface. The photoreceptor belt is stretched in the form of a loop around a plurality of rollers so as to be rotated for carrying a formed image. Both ends of the photoreceptor belt are bonded in the manner that the leading end in relation to the rotation direction is positioned inside than the trailing end in relation to the form of loop and the inner surface of the trailing end is superimposed on the outer surface of the leading end. Cleaning device for cleaning the imaging surface of the photoreceptor belt is disposed to have a cleaning direction opposite to the rotation direction of the photoreceptor belt. The photoreceptor belt is positioned to stop where the bonded ends of the belt are proximate to the corona charging device.

Abstract: An image forming apparatus is provided with a rotatable upper cover, one surface of which serves as a first exit tray on which recording sheets are discharged with image sides face downward, the other surface of which serves as a second exit tray on which recording sheets are discharged with image sides face upward. Guide members which are activated in accordance with the rotation of the rotatable upper cover are provided above delivering rollers, thereby the recording sheets delivered by the delivering rollers are selectively discharged with the image sides either face downward to the first exit tray or face upward to the second exit tray.

Abstract: A color image forming apparatus for forming a color image. An image retainer is provided for carrying the color image, and a charger charges a surface of the image retainer. A latent image former forms a latent image on the charged surface of the image retainer, and a multicolor developer develops the latent image. A black developer develops the latent image. A transfer sheet conveyer conveys a transfer sheet and transfers the developed latent image onto the transfer sheet. A cleaner cleans a residual developer on the surface of the image retainer. The image retainer, either one of the black developer or the multicolor developer, and the cleaner are formed as a detachable processing cartridge, and the rest of the black developer or the multicolor developer is detachable to the body of the color image forming apparatus.

Abstract: A color image forming machine such as a copier or a printer for producing a toner image, corresponding to an original image, on a recording sheet. The color image forming machine has a photoreceptor for forming the toner image on its surface; a transferrer for transferring the toner image from the photoreceptor to the recording sheet; and a fixer for fixing the toner image on the recording sheet. The fixer includes (1) an endless heat belt which is supported by a heat roller and a separation roller; and (2) an endless conveyance belt which is supported by a pressure roller and another separation roller; in which the endless heat belt and the endless conveyance belt are partially pressed together by the first pair which are inclined relative to one another, and the second pair so that a nip region is created between the first pair of rollers and the second pair of rollers. The endless heat belt and the endless conveyance belt have a glossy surface.

Abstract: An image forming apparatus in which a process cartridge, including an image carrying member and an operation member with respect to image forming, facing the image carrying member, is movably provided. An opening on the process cartridge in accordance with the operation member is covered by a shielding member in the main body of the apparatus when the process cartridge is moved from the apparatus in response to an opening movement of an external cover which provides access to the interior of the apparatus.

Abstract: In an apparatus for forming a color toner image, a photoreceptor is disposed at one side of a sheet passage so that a transfer sheet is conveyed through the sheet passage and is brought in contact with the photoreceptor on a transfer station and an exposure device is disposed at the other side of the sheet passage so that an image light irradiated from the exposure device crosses the sheet passage and proceeds to the photoreceptor.

Abstract: A method for determining toner adhesion amounts of plural color toners on a photoreceptor. The method includes the steps of: (1) forming plural reference latent images, each of which is corresponding to a respective component color image of a reference toner image; (2) developing the reference latent images, each of which is developed with a respective color toner of the plural color toners, so that developed reference latent images are superimposed, each at a time, on the photoreceptor to form the reference toner image; (3) detecting the toner adhesion amounts of the plural color toners by detecting the reference toner image every time when one of the developed reference latent images is superimposed on the same portion of the photoreceptor; and (4) determining whether the toner adhesion amounts of the plural color toners are normal or abnormal according to results of the detecting step.