Abstract: In a color image forming apparatus has a interchangeable belt-shaped image forming body stretched between horizontally disposed rollers and a plurality of developing means located below the belt-shaped image forming body. A passage for the transfer paper conveyance unit preferably as well as a fixing unit can be opened so that a process unit comprising the above-mentioned belt-shaped image forming body can be attached to and detached from the apparatus in the same direction as the above-mentioned passage for the transfer paper conveyance unit.Furthermore, the feeding operation for a sheet by-pass or loading and unloading operation for the recording paper cassette can be also carried out in the same direction as the above-mentioned passage of the transfer paper conveyance unit.

Abstract: A color image reader for discriminating a color component of a light image, comprising a first photoelectric transfer device for transferring visible range light to an electric signal, a second photoelectric transfer device for transferring infrared range light to another electric signal, and a discriminator for discriminating between a chromatic portion of the light image and an achromatic portion of the light image according to the two different electric signals.

Abstract: An image forming apparatus wherein a recording paper receiving cassette can be moved to a first position where the cassette is stored in the apparatus body and a second position where one portion of the cassette is withdrawn from the apparatus body so that the paper feed can be carried out, wherein when the cassette is withdrawn further from the apparatus body the cassette can be removed from the apparatus body. A process cartridge including a photosensitive belt and a plurality of developing devices are arranged around the photosensitive belt. The process cartridge is disposed above the recording paper receiving cassette, wherein the process cartridge can be withdrawn in the same direction as that of the recording paper receiving cassette when the recording paper feed path is opened.

Abstract: The invention provides a color image forming apparatus provided with an image carrying unit including a rotatable photoreceptor, a developing unit including a plurality of developing devices, and a cleaning unit. The apparatus is formed with a lower casing and an upper casing. In the upper casing, the image carrying unit, the developing unit and the cleaning unit are accommodated, in which at least two kinds of the units are incorporated in a cartridge capable of being detachably installed in the upper casing. The upper casing is adapted pivotal between an open position and an operation position around an axis which is disposed parallel to the rotation axis of the photoreceptor. When the upper casing is pivotted to the open position, the developing unit is so disposed that a side of the developing unit facing the photoreceptor becomes higher than other side of the developing unit.

Abstract: A color image forming apparatus wherein a belt-shaped image retainer faces an image forming device. The image forming device includes a charging device, exposure device and a plurality of developing devices which are juxtaposed with each other. The belt-shaped image retainer is in the form of a cartridge which is mounted removably in the apparatus body. The cartridge has a closable cover divided into several sections which are arranged at the positions facing the image device. The belt-shaped image retainer has a transversely movable shutter member for protecting spaced apart surface portions of the image retainer which would be otherwise exposed when the upper casing of the apparatus body is opened or when the image retainer is removed from the upper casing, by moving the shutter member transversely to cover the spaced apart exposed surface portions of the image retainer.

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 camshell type photoelectric color image printer includes a photoreceptor for holding a latent image on its surface, a charger for charging the surface of the photoreceptor, a laser writer for forming a latent image on the charged surface of the photoreceptor, plural developers for developing the latent image with color toners, a transfer drum for holding a recording sheet on which the developed latent image is transferred, a cleaner for cleaning residual toner on the photoreceptor, and a cartridge which holds the photoreceptor, the developers, the cleaner and the transfer unit. The developers are located under the photoreceptor, and the cartridge is removable from the color image printer. An upper part of the color image printer is movable relative to the main body of the printer.

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: 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 including a double feeding preventing mechanism which is arranged at an outlet side of a sheet feeding unit so that only one transfer material is fed, a sheet-feed controller which is stopped immediately after a leading end of the transfer material fed from the sheet feeding unit abuts against a nip portion between a pair of registration rollers, and a conveying controller for controlling rotation of the registration rollers such that the registration rollers are rotated after a sheet feeding operation is stopped so as to convey the transfer material to a predetermined position at low speed and are then rotated to convey the transfer material from the predetermined position to a transfer position in synchronism with a latent image formation timing.

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 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: Disclosed is an apparatus for forming a color image on a photoreceptor, in which along the rotation direction of the photoreceptor there are provided an imagewise exposure process to form a latent image, a development process including a plurality of developing devices to form a color toner image, each of the plural developing devices having a toner hopper, and a transfer process to transfer the formed color toner image onto a copy paper. The apparatus comprises a housing for including at least the photoreceptor, the plural developing devices and the plural toner hopper as one unit, and a support guide for supporting the housing to be movable in the axial direction of the photoreceptor so that the unit is attached to and detached from the apparatus.

Abstract: A multicolor image forming apparatus wherein a plurality of developing devices for forming a multicolor image are integrally supported by a support member which can be inserted into and withdrawn from an apparatus body, and a plurality of resupply devices for replenishing toner particles are mounted on each of the developing devices. Each of the developing devices and each of the resupply devices corresponding to each of the developing devices are automatically connected to and disconnected from each other, when the support member is inserted into and withdrawn from the apparatus body. The support member further supports an image retainer and if necessary a cleaning member integrally.

Abstract: An image processing method and apparatus wherein document information is separated by using an optical device into two colors that are complementary to each other, converted photo-electrically and processed by using a photo-electric conversion device, and extracted on the basis of the result of processing by using a color extraction information generation device, and a color information designated by the color extraction information of the color extraction information generation device is stored in a color information storage device.

Abstract: A thermosetting powder coating composition having good handling characteristics and capable of being baked under relatively mild conditions and providing a coating having practically satisfactory properties. This coating composition is prepared by incorporating in 100 parts by weight of an epoxy group-containing acrylic or methacrylic copolymer having a glass transition point of 30.degree. to 90.degree. C. and a weight average molecular weight of 2,500 to 30,000, said copolymer consisting of 3 to 35% by weight of acrylate or methacrylate monomer units and 97 to 65% by weight of ethylenically unsaturated monomer units, 3 to 40 parts by weight of a specific diphenol having at its both terminals hydroxybenzoic acid ester structures as represented by the general formula: ##STR1## wherein R.sub.