Abstract: A color image forming apparatus having an image retainer, a cleaning device for removing residual toner particles on the image retainer, and a device for releasing the cleaning device from the image retainer, which are integrally constructed as a process unit and can be taken out from an apparatus body. The cleaning device is in pressure contact with the image retainer when the process unit has been taken away. The device for releasing the cleaning device is mounted on the apparatus body.

Abstract: A multicolor image forming apparatus includes an image input means for outputting at least a character, a character size, and character coordinate data on a screen as image code data on the basis of input image data, a font storage section for storing font data and outputting the font data in accordance with an input address signal, a font data conversion sectin having a function of converting the image code data into image data consisting of pixel data on the basis of the font data, and an image buffer memory for temporarily storing the image data output from the font data conversion section. Toner images are frame-sequentially formed in layers on an image forming body in units of color components on the basis of the obtained image data, thereby forming a multicolor toner image.

Abstract: The invention provides an apparatus for forming a latent image on a photoreceptor. In the apparatus, there are provided an image reader including a scanning device for performing a reciprocal movement along an original document, a reading device for reading an image on the original document and for outputting an image signal in the outward movement of the scanning device, and a memory for storing the image signal; and an image writing device for writing a latent image on the photoreceptor. The image writing device has a first writing mode in which a latent image corresponding to the image signal outputted from the reading device is written in synchronization with the outward movement of the scanning device, and a second writing mode in which a latent image corresponding to the image signal outputted from the memory is written. The scanning device is adapted to perform the backward movement in the second writing mode.

Abstract: A color image forming apparatus has a plurality of developing devices and an automatic paper feed unit and a manual paper feed unit, each paper feed unit having a paper feed cassette. The paper feed units are provided below a belt-shaped image retainer. Paper ejection ports are provided above the image retainer for ejecting transfer materials which are fed from a paper feed unit, one of the paper ejection ports being selected according to the thickness of the transfer material. A thermal fixing condition is varied according to the transfer material thickness.

Abstract: The invention provides an apparatus for forming a color toner image on a photoreceptor belt. The photoreceptor belt is stretched to form a loop around a plurality of rollers and installed in a cartridge which is made to be detachable from the apparatus. The cartridge is made to additionally house a container for collecting residual toner removed from the photoreceptor belt or a toner supply unit for supplying toner to a plurality of developing devices.

Abstract: The invention provides a color image forming apparatus with photoreceptor belt. In a roll of the photoreceptor belt provided two pieces of rotatable rollers and guide plate with a curved surface so that the photoreceptor belt is moved while slidably coming in contact with the curved surface of the guide plate. Along the outer surface of the roll of the photoreceptor belt provided a plurality of developing devices at the curved surface to form a color toner image on the photoreceptor belt.

Abstract: A method of cleaning an image retainer by removing remaining toner particles from the retainer after transferring a multi-color toner image which is obtained by a multi-color toner image forming process wherein charging, image writing-in, and developing steps are repeated at least twice, abutting a cleaning member against the retainer after a final image writing-in step of the image forming process has been completed, and releasing the cleaning member from abutment after the cleaning has been completed but not during the image writing-in step for forming a next multi-color toner image.

Abstract: An electrostatic image forming apparatus for forming a color image wherein plural developers are located substantially under the image retainer, at least two of the image retainer, the developer, and the cleaner being formed as a detachable unit.

Abstract: An image-forming apparatus of the electrophotographic type. Color images are made while also enabling formation of a sharp black image formed by utilizing a set of color toner development units, at least one of which is replaceable by a black toner development unit when black toner is required. This results in a simpler, more compact, and effective image-forming apparatus.

Abstract: A color image forming apparatus for forming a plurality of toner images on a rotating image retainer, wherein the image retainer, a group of developing devices disposed below the image retainer and a cleaning device disposed above the image retainer are integrated to constitute a process unit, toner recovered by the cleaning device is stored in the process unit, and the image retainer can be removed from the process unit.

Abstract: The invention provides an apparatus for forming a toner image by reversal development. In the apparatus, there are provided an electric charger for uniformly charging a photoreceptor to a given electrostatic potential; the photoreceptor discharging in response to an exposure light to form an electrostatic latent image, the photoreceptor having a predetermined light decay curve indicating a relation between an amount of the exposure light and a discharged potential on the exposed portion wherein an absolute value of the differential coefficient of the light decay curve is small when the amount of the exposure light is small and the value sharply becomes large when the amount of the exposure light increases; a laser beam exposure device for exposing the photoreceptor with a dot-shaped light beam; and a developing device for providing toner onto the exposed portion of the latent image, thereby forming a toner image.

Abstract: The invention provides a color image forming apparatus capable of forming a mono-color image and a multi-color image on a rotatable photoreceptor having a given circumferential length. In the apparatus, there are provided a selection switch for selecting either a mono-color mode for forming a mono-color image or a multi-color mode for forming a multi-color image, and a control circuit responsible to a selection signal of the selection switch so that, when the multi-color made is selected, an image size of a multi-color image is restricted within a maximum size corresponding to the circumferential length of the photoreceptor.

Abstract: A multicolor image forming apparatus having an apparatus body and plural kinds of processing devices such as a photoreceptor, an electric charger for providing electric charge on the photoreceptor, an image exposure device for performing image exposure corresponding to multicolor image information on the charged photoreceptor, a developing device including a plurality of developing sub-devices for developing a latent image formed on the exposed photoreceptor into a toner image, a cleaner for cleaning a toner remaining on the photoreceptor after the toner image has been transferred to a copy paper, a plurality of supply devices for supplying toner to each of the plurality of developing sub-devices, and a color process cartridge for accomodating at least the photoreceptor and the plurality of developing sub-devices among the plural kinds of processing devices.

Abstract: A color image recording apparatus capable of detachably accommodating an interchangeable process cartridge incorporating plural kinds of developing devices. A plurality of kinds of interchangeable process cartridges are provided differing in the kind of developing devices incorporated therein, and each of such process cartridges has a predetermined operation mode corresponding to the kind of developing devices incorporated therein. Each of the plural kinds of process cartridges is adapted to be associated with a card-shaped memory storing data representing the predetermined operation mode. In the apparatus is provided an electric connection for forming an electrical circuit between the card-shaped memory associated with the accommodated process cartridge and the control device. The control device receives data from the card-shaped memory through the electric connection, and based thereon performs the predetermined operation mode of the accommodated process cartridge.

Abstract: A developing apparatus including a developer housing for holding a two-component type developer including toner and a carrier, and a toner housing holding toner to be used to replenish the developer. The developer housing and toner housing are interconnected by a passageway shaped so that toner supplied to the developing housing and the developer contained therein form an interface adjacent to the passageway, in the developer housing. By so shaping the passageway, the amount of toner added to the developer can be adequately controlled, without the use of regulating devices.

Abstract: An apparatus having a plurality of developing devices for forming a multiple toner picture image composed of a plurality of layer toner picture images prepared from developed latent picture images formed on an image retainer by turning the image retainer a plurality of times. In the apparatus, latent reference images of different colors are formed on regions of the image retainer based on reference signals and the plurality of developing devices are used to develop the latent reference images to form a plurality of reference toner images. The data derived from the reference toner images is used to set up the image-forming conditions for forming a latent picture image on a common region of the image retainer, based on picture image signals received by the apparatus, when the toner picture image is formed on the image retainer.This application is a continuation of U.S. Ser. No. 849,709, filed Apr. 9, 1986, now abandoned, which in turn is a division of U.S. Ser. No. 757,519, filed July 19, 1984, now abandoned.

Abstract: A color image processing apparatus including an image-reading device for reading a color image on an original to obtain first color image data, an image memory which stores the first color image data, and a factor memory which stores a predetermined correction factor. A color correction system corrects the first color image data with the correction factor. An image-producing apparatus produces a color copy image on the basis of the corrected first color image data, where the image-reading device reads the color copy image to obtain second color image data. The image-processing apparatus further includes a processing member which performs a comparison between the first color image data stored and changes the correction factor on the basis of the comparison.

Abstract: The object of the present invention is to provide an image forming apparatus capable of enabling high-speed continuous copy of an same single-color image, wherein the apparatus is incorporated with a shift register between an image reader and a laser beam generated for performing imagewise exposure onto a photoreceptor. The shift register has a circulation circuit connecting between an output and an input side thereof. After an image data corresponding to a sheet of original document is inputted into the shift register, the circulation circuit is actuated and circulates the image data, thereby repeatedly outputting the image data to the laser beam generator by the number of required times.

Abstract: An image forming method wherein a latent image is formed by one of plurality of latent image forming devices and developed by one of plurality of developing devices. The above steps are repeated to form an image. An image forming apparatus having a first latent image forming device, a first developing device, a second latent image forming device, and a second developing device sequentially arranged in face of an image retainer in this order.

Abstract: The invention provides an electrostatic copier having a smoothing member at an upstream side in the developer conveying direction in the vicinity of a developing area between a developer conveyer and an image-forming member in order to smooth a developer layer on the conveyor prior to transfer of the image forming member. Further, one surface of the smoothing member is so arranged as to come in contact with the image-forming member and another surface smoothes the developer layer. The developer conveyer has a magnet member therein and the magnet member is positioned to face the smoothing portion of the smoothing member.