Abstract: A color image forming apparatus such as a printer or a copier. The apparatus includes: a photoreceptor, having a transparent body, for forming a toner image; a charger for charging the photoreceptor; a LED array, accommodated inside the photoreceptor, for imagewisely exposing the photoreceptor with exposure light so as to form a latent image on the photoreceptor; a developer for developing the latent image with toner so as to form a toner image on the photoreceptor; in which a process of forming the toner image is repeated for plural times so that plural toner images are superimposed to from a composite toner image; a transferor for transferring the composite toner image onto a recording medium; and a photodetector, accommodated inside the photoreceptor, for detecting light from the photoreceptor in which the light has a high transmission factor for the photoreceptor.

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: A color image forming apparatus in which a charging, imagewise exposing and developing operations are repeated onto an image forming drum to register different colored toner images thereon and thereby to transfer simultaneously the toner images onto a recording sheet, includes four imagewise exposing units which are disposed inside the image forming drum and are fixed in a main body of the image forming apparatus. Two each of the exposing units and the developing units are disposed respectively on both sides with predetermined angles with respect to a vertical line passing through the center of the image forming drum. The apparatus further includes a transferring device and a cleaning device are disposed respectively with predetermined angles on different one side of the vertical line below a horizontal line intersecting with the center of the image forming drum.

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 electrophotographic color image forming machine registers which a second color toner image on a first color toner image which has been previously formed on an image carrier to form a color image. The registered images are then transferred onto a recording sheet. The machine includes control apparatus that includes first and second exposure control modulators which respectively control an exposure amount of at least one of the first color toner images and the second color toner image. A smoothing processor controls at least one of a size and a position of at least one of the first and second color toner dot images within each of a plurality of pixels and a discriminator determines whether one of the size and the position of the dot image should be controlled.

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: 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: The invention provides a method of forming an image on an imaging surface of a photoreceptor having a light decay characteristic so that the potential of the imaging surface is slowly decayed in an initial period of exposure and the potential of the imaging surface is sharply decayed in a middle period of exposure. The imaging surface is charged to an electric potential, exposed with a light beam, wherein the light beam has the maximum light amount I.sub.0 in the light amount distribution thereof on the imaging surface so as to satisfy following condition:1.2.times.P.sub.178 .ltoreq.I.sub.0 .ltoreq.2.5.times.P.sub.1/2,in which P.sub.1/2 is a half decay exposure light amount for decaying the potential of the imaging surface from an initial potential value before the exposure to the half of the initial potential value.

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: In an image forming machine in which a latent image is formed on an image carrier using an exposure device corresponding to an image forming signal, and a toner image is formed by a developing device using toners, there is provided with a first adjustment device by which an adhesion amount of toner is adjusted, a discriminator by which an isolated dot or an edge dot is discriminated, a second adjustment device by which an adhesion amount of toner is adjusted according to a discrimination result by the discriminator, and a controller by which the adjustment conditions of the adhesion amount of the second adjustment device differ corresponding to the discriminated isolation dot or edge dot, and areas other than the discriminated dots.

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: 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 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: In a toner image forming apparatus capable of changing the fixing condition of a fixing device to fix a toner image on a recording sheet, there is provided a control device to change at least one of the charging condition of a charging device, the exposure condition of the exposing device and the developing condition of the developing device to change the toner amount in the toner image in accordance with the change in the fixing condition.