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: An image forming apparatus includes a rotary image forming body; a charger provided around the image forming body for charging the image forming body; a plurality of imagewise exposure devices for imagewise exposing the charged image forming body to form respective latent images thereon; and a plurality of developing devices for developing the respective latent images formed on the image forming body to form respective toner images. A plurality of different color toner images thus formed by the respective chargers, the respective imagewise exposure devices and the respective developing devices are superimposed on the image forming body, thereby a color toner image is formed. The image forming apparatus further includes a transfer device for transferring the color toner image on the image forming body onto a transfer member; a cleaning device for removing a residual toner on the image forming body; a support member for supporting the plurality of exposure devices.

Abstract: An optical system assembling method in an image forming apparatus in which there are provided an image forming body around which a plurality of exposure device each having a linear exposure optical system to imagewise expose on the image forming body, and a plurality of developing device containing respective color toners different from each other which are superimposed on the image forming body to form a color toner image, the method further having the steps of: lighting the exposure optical system; forming an image emitted from the exposure optical system on a sensor which is disposed at a position corresponding to a photosensitive surface of the image forming body with respect to the exposure optical system; adjusting a position of the exposure optical system on the basis of a result of the image forming so that a focal point of the exposure optical system is coincident with a surface of the sensor; and fixing at the adjusted position the exposure optical system to an optical system supporting body provide

Abstract: A multi-color image forming apparatus includes a rotatable endless image forming member, plural exposure devices provided inside of the image forming member, and plural units each including a charger to electrically charge an outer surface of the image forming member and a developing device containing a color toner of plural different color toners to develop a latent image. Each of the plural units are disposed on the outer surface of the image forming member so as to be opposite to one of plural exposure devices so that multi-color toner images can be formed on the outer surface of the image forming member during a single rotation of the image forming member. in addition, each of the plural units is detachable from the apparatus independently of other units.

Abstract: An image forming apparatus includes: a photoreceptor drum; a charger for charging an outer surface of the photoreceptor drum; image exposure devices each for exposing the photoreceptor drum to form a latent image thereon, wherein the image exposure devices are provided inside the photoreceptor drum, and are detachably mountable with the photoreceptor drum to the image forming apparatus; a developing device for developing the latent image to form a toner image on the outer surface of the photoreceptor drum; and a supporting member on which the image exposure devices are mounted, wherein the supporting member and the photoreceptor drum are connected through bearing members on both ends of the photoreceptor drum, and the supporting member has an engaging portion for engaging with a part of the image forming apparatus to fix the image exposure devices through the supporting member, while the photoreceptor drum is rotated around the image exposure devices through the bearing members.

Abstract: A color image forming apparatus includes a drum type image forming body; four charging devices for charging the image forming body; four exposure devices fixed on the main body for imagewise exposing the charged image and forming body to form a latent image; four developing devices each for developing the latent image to form a different colored toner image. After operations by the charging devices, the exposure devices and the developing devices are repeated to superimpose the different colored toner images on the image forming body, the superimposed colored toner images are transferred by a transfer device including an intermediate transferring member and a transfer member in contact with the intermediate transferring member onto a recording material at one time.

Abstract: An apparatus for forming multi color toner images includes a photoreceptor drum which has an opening at a first end through which an inside of the photoreceptor drum is accessible, and which has an outer surface on which multi color toner images are formed. A supporting member is provided which is capable of being inserted into the inside of the photoreceptor drum through the opening thereof. A cover member is provided on a first end of the supporting member for covering the opening. A plurality of exposing devices are mounted on the supporting member so that the plurality of exposing devices and the supporting member are incorporated inside the photoreceptor drum when the cover member is fixed so as to cover the opening. A plurality of charging devices are provided around the outer surface of the photoreceptor drum for charging the outer surface of the photoreceptor drum.

Abstract: In a color image forming apparatus, plural different colored toner images are sequentially formed on an image forming body by repeating respective operations of plural chargers, plural imagewise exposure devices and plural developing devices so that a superimposed color image is formed on the image forming body. The color image forming apparatus further includes a detector provided inside and facing the image forming body, downstream of a developing device located in a most downstream position among the plural developing devices, for detecting the superimposed color image on the image forming body.

Abstract: A color image forming apparatus such as a copier or a printer for forming a multicolor toner image.

Abstract: An image forming apparatus such as a copier or a printer for forming a color image. The image forming apparatus includes: a transparent photoreceptor drum for retaining a multi-color toner image in which the wall-thickness and an inner diameter of the drum are respectively between 2.5 mm and 8 mm and between 60 mm and 200 mm; plural chargers, provided on the periphery of the photoreceptor drum, for charging the drum surface; plural imagewise exposure systems, provided inside of the photoreceptor drum, for forming latent images on the drum surface; and plural developers, provided on the periphery of the photoreceptor drum, for developing the latent images with different color toners so as to form a superimposed multi-color toner image on the drum surface while the photoreceptor drum is being rotated one time.

Abstract: A color image forming apparatus includes a plurality of chargers, imagewise exposure devices and developing devices. During a single rotation of an image forming body, a sequence of charging, exposing and developing is repeated to superimpose toner images, and then the toner images are transferred onto a recording medium. Each exposing position on a circumferential surface of the image forming body is arranged downstream of a developer casing and upstream of a line connecting the centers of the image forming body and developing sleeve. The following expression is satisfied:L.sub.1 >L.sub.2 >vT+wwhere L.sub.1 represents a circumferential distance along the periphery of the image forming body between the line connecting the rotational center of the image forming body and the tip end of the developing casing and a line connecting the rotational center of the image forming body and the rotational center of the developing sleeve; L.sub.

Abstract: A corona-discharging type charging device for charging a photoreceptor includes saw tooth-shaped electrodes facing the photoreceptor; side plates applied with a DC bias voltage Vs and provided on both sides of the saw tooth-shaped electrodes; and a control grid applied with a DC bias voltage Vg and provided between the saw tooth-shaped electrodes and the photoreceptor.

Abstract: A color image forming apparatus wherein an image forming body has a inner surface and a outer surface, a charging device electrically charges the outer surface, and an exposure device imagewise exposes the inner surface. A developing device is used to form a first toner image on the outer surface. A unit is detachablly mounted in a housing of the apparatus, wherein the image forming body and a plurality of the exposure devices are provided in the unit.

Abstract: A color image forming apparatus includes a plurality of chargers each provided in a periphery of an image forming body for charging the image forming body; at least two of a plurality of imagewise exposure devices each equally spaced with respect to the image forming body, for imagewise exposing a charged image forming body to form a latent image; and a plurality of developing devices each provided in the periphery of the image forming body to develop the latent image to form a toner image.

Abstract: An image forming apparatus for forming an image on an image forming body by scanning a plurality of modulated laser beams is disclosed. The apparatus is provided with a generator to generate a plurality of reference signals each with a differrent phase from other reference signals, a detector for detecting the difference of image density between two adjacent image pixels, combined modulator to generate a modulated laser beam by combining a selected laser beam, a selected reference signal and the image density. The detector classifies each pixel as one of an edge starting pixel, an edge ending pixel, and a non-edge pixel based on the value of image density difference relative to positive and negative threshold values. The selection of the laser beam and the reference signal is based on the image density difference detected by the detector and the class of the pixel.

Abstract: A color image forming apparatus provided with plural charging devices, plural image exposure devices, and plural developing devices which are arranged around the outer circumference of a photoreceptor so that a color image is formed during a single rotation of the photoreceptor. The apparatus comprises a supporting cylinder for enclosing the photoreceptor and for supporting the plural image exposure devices thereon.

Abstract: In an apparatus in which a yellow, magenta, and cyan toner images are superimposed on a photoreceptor drum made of a transparent material, an image exposure device is provided in the photoreceptor drum and emits exposure lights whose wavelength has a spectral reflective ratio lower than 30% for at least two of yellow, magenta, and cyan toners. The image forming processes is controlled so that a toner image for which the exposure lights have a spectral reflective ratio larger than 30% is formed after toner images for which the exposure lights have a spectral reflective ratio lower than 30% have been formed.

Abstract: In a color image forming apparatus in which each of charging devices, image exposure devices and developing devices is provided in plural sets corresponding in number to plural different color components and placed in such an arrangement that the plural different color component toner images are superimposed on the image carrying member during a single rotation of the image carrying member, all of the plural image exposure means, and the image carrying member are constructed in a single body and is shiftable together in a direction perpendicular to the rotation axis of the image carrying member from or to the working position of the image carrying member.

Abstract: A developing apparatus for developing an electrostatic latent image on an image retainer with two-component developer has a rotatable sleeve having a closest position on which the sleeve comes closest to the image retainer, a first magnet fixed in the sleeve in close proximity to the closest position, a second magnet disposed upstream of the first magnet in relation to a rotation direction of the sleeve and a control electrode member. The control electrode member includes an insulating plate member arranged either to be brought into contact with or to be positioned adjacent to the sleeve and a line-shaped electrode member fixed to the plate member.

Abstract: A color image forming apparatus includes a controller to control an image carrier, plural chargers, plural image exposing devices, plural developing devices so that plural color toner images are formed one after another and superimposed on the image carrier, and a regulator to regulate a deviation in position among the plural color toner images.