Abstract: An electrographic printer device contains a first printing unit and a second printing unit, each printing unit containing at least one developer unit. A second developer unit in the second printing unit employs a coating method that works without contact, for example the toner spraying method, and inserts colored toner images into toner-free regions on the photoconductor drum.

Abstract: A color image forming apparatus includes a plurality of image forming sections independent of each other. The image forming sections store respective toner of different colors that are chargeable to the same polarity. All the toner are implemented by the same binder resin and provided with the same particle size distribution. Further, developing units each storing toner of particular color are identical in specification. When two-ingredient type developers are used, the developers contain an identical carrier. The apparatus recycles the toner of different colors to the respective developing units. The alien color toner collected in each developing unit is prevented from remaining by being chargeable to the same polarity.

Abstract: A low toner pile height color image reproduction machine is disclosed for forming full-gamut toner images approximating a “look and feel” of offset lithographic images.

Abstract: A low cost process multicolor image reproduction machine includes a rotatable endless toner image receiving and transfer member for cyclically building up a multicolor image from a plural number of received color separation toner images; a sheet handling system including a back up roller defining a toner image transfer nip against the rotatable endless toner image receiving and transfer member; a rotatable photoreceptor member forming a contact electrostatic printing (CEP) nip with the rotatable endless toner image receiving and transfer member for separating toner image areas from toner background areas of a color separation toner image formed on the photoreceptor member; imaging devices for cyclically forming a plural number of color separation toner images on the photoreceptor member, and a controller for controlling formation of, and build up into a multicolor toner image, of the plural number of color separation images, as well as, transfer of the multicolor toner image onto a copy sheet.

Abstract: A developing system is provided for forming a full-color image, which includes

Abstract: An image forming apparatus in which an image forming device has developing device for developing an electrostatic image formed on an image bearing member. The developing device has a first developing section for developing use of a first cyan toner, a second developing section for developing by use of a first magenta toner, a third developing section for developing by use of a yellow toner, a fourth developing section for developing by use of a second cyan toner that is lighter than the first cyan toner, and a fifth developing section for developing by use of a second magenta toner that is lighter than the first magenta toner. A sixth developing section is provided for developing by use of a black toner. A first rotator supports the first, second, third, fourth, fifth and sixth developing devices, and a second rotator supports the fourth and fifth developing devices.

Abstract: An image forming apparatus including a plurality of process stations vertically arranged each of which includes an image bearing member on which a latent image is to be formed and a developing device for developing the latent image, image bearing member driving devices, for driving the image bearing members, development driving devices, for driving the developing devices, and a transfer material bearing and conveying device for bearing and conveying the transfer material, wherein, while the transfer member is vertically conveyed through transfer nips that are formed by the transfer material bearing and conveying device and the image bearing members of all of the plurality of process stations, images formed by the plurality of pocess stations are sequentially transferred to the transfer material to form an image, and wherein process stations to be used for image forming can be selected, and the image bearing member driving devices and the development driving devices are controlled, so that, during an image for

Abstract: A color image forming apparatus includes a photosensitive belt, which consists of a resinous base sheet and an organic photosensitive layer formed thereon. The photosensitive layer consists of a charge transport layer and charge generation particles dispersed therein. The image forming apparatus ensures good color image quality even if the developer used for this former is toner made of styrene-acrylic resin. The image forming apparatus also includes developing rollers in contact with the photosensitive belt. Suitable shearing force can be applied to the toner if the speed ratio of the developing rollers to the photosensitive belt ranges from 1.3 to 2.0. The developer includes an external additive which has a particle diameter of 30 or more nm. The external additive can effectively prevent printed sheets from halation.

Abstract: An image forming apparatus is provided which can selectively drive a plurality of developing units by a simple structure accommodated in a small space. Two image stations are arranged along a direction of movement of an intermediate transfer belt. Each of the image stations is provided with a plurality of developing units arranged around a photosensitive drum. A developing unit driving system drives the plurality of developing units. A switching mechanism switches a transmission path of a power generated by the developing unit driving system so that the power is selectively transmitted to one of the developing units.

Abstract: The present invention provides an image forming apparatus that has a plurality of image bearing members for bearing developer images thereon, and a plurality of developer containing portions for containing developers therein and provided correspondingly to respective ones of the plurality of image bearing members, wherein the developer images can be transferred from the plurality of image bearing members to a transferring member moving along the respective transferring positions of the plurality of image bearing members, and of the plurality of developer containing portions, a developer containing portion having greatest developer containing quantity is provided at least one of upstream of the most upstream one of the plurality of image bearing members and downstream of the most downstream one of the plurality of image bearing members, with respect to a moving direction of the transferring member.

Abstract: Imaging system for effecting single pass, multicolor printing of a color image, wherein the imaging system includes a plurality of contact electrostatic printing engines operable in serial fashion upon a copy substrate, wherein each contact electrostatic printing engine images and develops a respective electrostatic latent image representative of a component of the color image, and subsequently transfers the developed component image to the copy substrate as the copy substrate proceeds in a single pass through the imaging system.

Abstract: An electrostatic image forming apparatus is disclosed. The image forming apparatus contains a toner used in the developing means having saturated moisture content at a temperature of 30° C. and a relative humidity of 80% of within the range of from 0.1 to 2.0% by weight, and the photoreceptor contains a siloxane resin having an electric charge transfer ability and a crosslinked structure in the surface layer.

Abstract: An image forming apparatus, including: a charger, arranged around an image carrier, for charging a surface of the image carrier; an exposure device, arranged around the image carrier, for exposing the surface of the image carrier, after it is charged by the charger, and for forming an electrostatic latent image on the surface of the image carrier; a developer device, having a developer carrier and arranged around the image carrier, for carrying developer with which the electrostatic latent image is developed so as to obtain a developed image; and a transfer device, arranged around the image carrier, for transferring the developed image onto a transfer material.

Abstract: A multicolor printer uses toner of two polarities applied on a photo conductor layer prior to the two toners being applied to a carrier. The photo conductor layer is provided with an image-wise illumination with regions of different illumination to form regions of different potentials. The regions of different potentials are developed by applying the toner of two polarities. Further colors of toner may be used, provided illumination with corresponding different illumination and provided charging of the photo conductor layer to change relative potentials is performed. An overall illumination of the photo conductor layer between developing steps changes potential levels on regions not covered by toner but not in areas covered by toner.

Abstract: An end of toner detector to be utilized in a toner cartridge of a developing apparatus of an image forming apparatus. A developing device develops latent images formed on an image bearing member so as to form toner images. A toner storage unit deposits toner to supply to the developing device. A light path forming unit protrudes from a wall of the toner storage unit into an interior of the toner storage unit and forms the light path through which light passes in the toner storage unit. A light sensor includes a light emitting unit which emits light and a light receiving unit which receives light emitted from the light emitting unit. Further, the light sensor outputs signals which smoothly change according to an amount of toner in the light path formed in the light forming unit.

Abstract: Developing devices are provided adjacent to a light sensitive element. An intermediate transfer drum is provided adjacent to the light sensitive elements. After exposure of the light sensitive element, a first color or third color image is formed on the light sensitive element. On the other hand, after exposure of the light sensitive element, a second color or fourth color image can be formed on the light sensitive element. The first color image is transferred from the transfer unit to the intermediate transfer drum at the first transfer portion, and the second color image is transferred from the transfer unit at the second transfer portion so as to be superimposed on the first color image. Similarly, the third color image is transferred so as to be superimposed on the second image and the fourth color image is transferred so as to be superimposed on the third color image to the intermediate transfer drum. Accordingly, the first to fourth color images are superimposed.

Abstract: A first developing unit comprising a plurality of developing rolls including a developing roll whose rotation direction is matched with the move direction of a photosensitive body and a developing roll whose rotation direction is made opposite to the move direction of the photosensitive body.

Abstract: A method for multicolor electrophotographic printing includes a photoconductive layer system having surface elements or surface regions that are provided with an initial negative potential, then are exposed to varying degrees and developed with negatively charged toner particles of a color. A uniform light source is arranged closed to the photoconductive layer system and then the surface elements are developed with a second color toner. In particular, the image being printed has image elements of different colors which correspond to different surface elements of the photoconductor. These surface elements are differently illuminated to achieve different potentials and are developed by color particles by depositing the color particles on the respective surface elements. The charge potential of ones of the surface elements is increased and then surface elements not covered by color particles are illuminated to reduce the charge potential there prior to subsequent development of further surface elements.

Abstract: A plurality of developing units each includes a case which accommodates toner containing pigment, a developing roller, a supply roller formed of an elastic member arranged to be pressed against a surface of the developing roller in such a manner as to supply toner to the surface of the developing roller and a conveying fin. The developing roller, supply roller, and conveying fin for each developing unit are angularly arranged in a particular manner.

Abstract: A toner is made or toner particles which contains a binder resin and a coloring agent, wherein the toner particles have a weight-average particle size in a range of 6.0 to 11.5 &mgr;m, and contains toner particles (a) with a particle diameter of 5 &mgr;m or less in a content ratio of 1 to 15% by number, and toner particles (b) with a particle diameter of twice or more the weight-average particle size in a content ratio of 5 wt % or less, and the number-average particle size D25 and the number-average particle size D75 respectively obtained when the cumulative number of the toner particles reaches 25% and 75% at the measurement of a cumulative toner particle distribution by number thereof are in the relationship of 0.60≦D25/D75≦0.95. A two-component developer includes the above-mentioned toner and a carrier.

Abstract: A multicolor image-on-image reproduction machine includes a main assembly, a controller, a movable image bearing member having a path of movement, and a plurality of air breakdown charge and development (ABCD) imaging units mounted along the path of movement for forming color separation toner images. Each (ABCD) imaging unit includes a photoreceptor having a photoconductive surface forming a toner image separation development nip with the movable image bearing member; a toner supply apparatus for applying a layer of toner onto the photoconductive surface; a charging device for uniformly charging the photoconductive surface through the layer of toner; and an exposure device connected to the controller for image-wise exposing of the photoconductive surface and the layer of toner to form therein image areas and background areas of a desired color separation image.

Abstract: A multicolor image reproduction machine includes a main assembly having an image bearing member, a controller, and a bias source for biasing the image bearing member. It also includes a plurality of color separation toner image forming units each having a photoreceptor including a photoconductive surface forming a toner image separation development nip with the image bearing member. Each imaging unit also includes a toner supply apparatus for applying a layer of toner of a particular color onto the photoconductive surface; a first charging device for uniformly charging the photoconductive surface; an exposure device connected to the controller for image-wise exposing the photoconductive surface and the layer of toner to form therein image areas and background areas of a desired image; and a second charging device connected to the controller for selectively reversing charge in the background areas of the desired image, so as to enable subsequent separation of the background areas from the image areas.

Abstract: A printing system using a recharge, expose and development image on image process color system in which there is an optional gloss development step is employed that results in the image having an uniform gloss and toner pile height. The printing system may be a single pass system where all of the color are developed in a single pass or a multi-pass system where each color is developed in a separate pass. The additional gloss development step results in optimal color quality.

Abstract: Apparatus and method for creating highly registered quality pictorial color images include a first tri-level xerographic module using first and second color marking materials for creating and developing a first tri-level image including custom CAD and custom DAD image areas having different voltage levels respectively to form a first composite color separation image; a transfer station for transferring the first composite color separation image onto an intermediate transfer member; a second tri-level xerographic module using third and fourth color marking materials for similarly creating and developing a second tri-level image including custom CAD and custom DAD image areas having different voltage levels respectively to form a second composite color image; a transfer station for transferring the second composite color separation image, in registration onto the intermediate transfer member; a third tri-level xerographic module using fifth and sixth color marking materials for similarly creating and developing

Abstract: A color image forming apparatus having a plurality of image forming units with each unit having a developing device and a photoconductive drum with a driven coupling device. A conveying device switches the plurality of image forming units by moving them successively between an image forming position and a waiting position. A photoconductive drum driving device removably engages the driven coupling device of the image forming unit that is positioned in the image forming position and having one driving coupling device for coaxially rotating the photoconductive drum of the image forming unit positioned in the image forming position together as one body. The photoconductive drum positioned in the image forming position is in contact with a transfer device wherein a peripheral velocity of either the photoconductive drum or the transfer device during use is higher than the a peripheral velocity of the other.

Abstract: A method and an apparatus for producing, in a single pass, an electrophotographic image comprising at least two colors. The photoconductive element is bipolar, and has a single active layer and a protective layer of diamond-like carbon.

Abstract: A color image forming apparatus includes a photoreceptor drum having an outer diameter of 50 mm to 100 mm and a rotational axis, four charging devices for charging the photoreceptor drum, and four exposure devices, provided inside the photoreceptor drum, for imagewise exposing an inner surface of the photoreceptor drum to form respective four latent images. Four developing devices are provided outside the photoreceptor drum at an upper section thereof for developing respective ones of the four latent images using respective different one-component type color developers to form four different color toner images in a superimposed manner on an outer surface of the photoreceptor drum during one rotation thereof the photoreceptor drum.

Abstract: In an electrophotographic image forming apparatus, a photoconductive element includes a photoconductive film having a thickness of 15 .mu.m or below. A light beam having a diameter of 50 .mu.m or below optically forms a latent image on the photoconductive element. Toner is caused to deposit on a dot image in an amount 1.2 times greater than on an area image. This is successful to minimize the variation of image quality and to render dots inconspicuous. The method of forming toner images is also included.

Abstract: A developing cartridge for developing a latent image formed on the photosensitive member, wherein the developing cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus, the developing cartridge includes a cartridge frame; developing means for developing, with toner, the latent image formed on the photosensitive member of the main assembly of the apparatus; a first projected portion outwardly projected from the cartridge frame portion adjacent one longitudinal end of the developing means; a second projected portion outwardly projected from the cartridge frame portion adjacent the other longitudinal end of the developing means; a first urging force receptor portion outwardly projected from the cartridge frame portion adjacent one longitudinal end of the developing means; a second urging force receptor portion outwardly projected from the cartridge frame portion adjacent the other longitudinal end of the developing means; a first contact portion outwardly projected

Abstract: An ion flow recording apparatus performs recording making density modulation every pixel. When developing on a fine grain toner is to be performed using a liquid developer for an electrostatic latent image, a developing unit (developing roller) is disposed to face a direction of gravity. Namely, a control valve is provided on a pipe for application of a developer to the developing roller or on a joint portion between the pipe and a developer tank, developing units of different two colors are joined to their developer tank portions, and a rotary shaft is provided on the joint portion to be positioned at a point of symmetry to provide alternate use of the two developing units upon turning them. Therefore, developing for a plurality of colors can be simply performed, and such turning of the developing units enables prevention of the toner from deposition in the liquid developer during developing, thereby making it possible to perform a clear recording.

Abstract: The image forming apparatus according to the present invention forms a high quality color image with multiple colors of toner in accordance with an input signal. An electrostatic latent image is formed on an image carrier in accordance with the image signal. A developing bias is applied to the image carrier to form a toner image of the latent image for multiple toner colors. To transfer the toner image to an intermediate transfer belt, a rotatable transfer roller is positioned opposite the image carrier and across the transfer belt for attracting the transfer belt toward the image carrier at a transferring position. To reduce the frictional force between the image carrier and the transfer belt, which causes color deviation when multiple toner images are transferred to the intermediate transfer belt, a toner is placed on the image carrier in front of a leading end of a first toner image formed on the image carrier.

Abstract: An image forming apparatus including a rotatable developing member having a plurality of developing devices for developing an image bearing member at a first developing station, and a second single developing device arranged upstream of the rotatable developing member for developing the image bearing member exclusively at a second developing station different from the first developing station. The second developing device has a cover portion covering the rotatable developing member, and a portion of the cover portion is disposed at a position spaced apart from a rotation axis of the rotatable developing member by a predetermined length in a horizontal direction away from the image bearing member. The rotatable developing member rotates in an opposite direction with respect to the direction of rotation of the image bearing member to prevent toner from scattering toward the optical system.

Abstract: An image forming apparatus having an image carrying member bearing an electrostatic image wherein the electrostatic image is visualized into a toner image by a developing device. The image carrying member is arranged for transferring the toner image to an intermediate transfer element while the image carrying member and intermediate transfer element are moving at a usual speed corresponding to the speed of movement of the image carrying member during toner image development. Multiple such toner images of different colors may be transferred in this manner to form multi-color images superimposed on the intermediate transfer element for subsequent transfer to a recording medium, usually paper.

Abstract: A color capable electrophotographic printer remains operable for monochrome printing when one or more toner cartridges are unavailable for use. Instead of reverting to an error state when a toner cartridge is missing or unavailable, the laser printer remains operable to print monochrome images or single "spot color" images using a single color and monochrome toner.

Abstract: REaD electrophotographic printing using additive color toners. Toners that are non-transmissive to exposing light are developed using inhibited image-on-image printing. Then, the photoreceptor is exposed to produce a latent image for a toner that transmits the exposing light. Finally, the latent image for a toner that transmits the exposing light is developed.

Abstract: Graphic matter, such as words and images, is printed on a document in bound form, such as passport, by forming the graphic matter by laser printing steps on a temporary substrate and provisionally setting the graphic matter thus formed on the temporary substrate. Thereafter, the temporary substrate is juxtaposed with its face carrying the image in contact with the rear face of a transparent substrate, and the image is transferred to the rear face of this latter. Then the transparent substrate is juxtaposed to the final substrate that is intended to carry the image, with its rear face in contact with the front face of the final substrate, and the two substrates are laminated together, so that the image remains enclosed in the laminate and is visible from the front face of the transparent substrate as if it were printed on the final substrate.

Abstract: Disclosed is a color image forming apparatus in which a plurality of developed images superposed one upon the other are transferred onto a recording medium. The transfer capability of the developing agent is improved by using a first developing agent containing a additive having a small average particle diameter, followed by using a second developing agent containing a second additive having a large average particle diameter larger. Alternatively, a first developing agent containing a first toner having a small roundness is used first, followed by using a second developing agent containing a second toner having a large roundness. Still alternatively, a first developing agent containing a small amount of a first additive is used first, followed by using a second developing agent containing a large amount of a second additive.

Abstract: In a color image forming apparatus, a plurality of image forming units 3Y, 3M, 3C and 3K, which correspond to a plurality of colors and with each unit including a developing device and a photosensitive drum, are retained so as to define a cylinder.

Abstract: A color image forming method and apparatus of the electrophotographic type with a plurality of liquid developing devices. In a plurality of liquid developing devices accommodating liquid developer comprising colored microparticles dispersed in an electrically insulated fluid medium are used to form toner images of different colors, which are electrostatically transferred and overlaid one over another on a transfer medium to produce an overlaid toner image. The color image forming method and apparatus providing excellent overlay transfer characteristics for toner images transferred to a transfer medium.

Abstract: A single pass, multi-color electrophotographic printing machine architecture uses a vertically oriented photoconductive belt. Transfer of the toner powder images occur at the lowermost portion of the photoconductive belt. The photoconductive belt is elliptically shaped, having a major and a minor axis. N image recording stations are positioned adjacent an exterior surface of the photoconductive belt on one side of the major axis thereof. N-1 image recording stations are positioned adjacent the exterior surface of the photoconductive belt on the other side of the major axis thereof. The image recording stations record electrostatic latent images on the photoconductive belt. This architecture optimizes image registration while minimizing the overall height of the printing machine.

Abstract: In an image recording method, toner images of the same color are electrographically formed in superposition onto a recording medium. The recording medium is paper, film, or the like. Each toner image is formed of toner particles. Particles having different sizes or optical densities may be used in different toner images. No wet system processing is involved. The image recording apparatus employing the method may have one or more drums on which latent images are formed. The latent images may be identical or may be varied based on the image density.

Abstract: A method and apparatus for reproducing color images using a non-interactive pyroelectric imaging process is disclosed. More specifically, the present invention is used to generate multiple layers of toner on the top surface of a pyroelectric imaging member without physical contact to the imaging member top surface. The ability to generate a composite image with different materials in this manner enables printing machines to use a pyroelectric imaging process to generate color images in the image on image (I-O-I) mode.

Abstract: A computer (500) with a graphics program, an eight-plane raster image processor program, an eight-plane print-sending program, and a contrast-control program is connected to a single-bit, four-pass, electrographic printer (430). One or more of the primary colors is individually divided into multiple layers (100', 200 . . . ), with each layer having an independently selectable contrast setting (300--330). The printer (430') is now capable of printing images with an improved color gamut and dynamic range.

Abstract: A system for determining, in real time, the precise color measurements of a colorant being applied in a printing apparatus, the colorant being a combination of two or more primary colorants. Light from a light source is transmitted through or reflected from the colorant mixture, and received by a sensor having a relatively small number of photodetectors, each photodetector having a different translucent primary-color filter thereon. Various special algorithms can be used to approach the accuracy of a spectrophotometer using a relatively simple light sensor.

Abstract: An imaging system is provided which combines the perfect registration capabilities of xerocolography to form perfectly registered red, green and blue images in a single pass in one mode of operation. In another mode of operation, the color gamut possible with RGB toners is extended using black toner to develop an image that is formed using a second imager or exposure device. The result is an extended gamut color imaging process using four colors side by side in a single pass with a minimum amount of color desaturation and with a minimum number of image registrations. Yet another mode of operation provides for creating K+2 colors in a single pass. The three or two colors may be used to form highlight colors and/or logo colors.

Abstract: An electrostatic-image developer which comprises: (i) a toner comprising: (a) toner particles containing carbon black in an amount of from 6 to 8% by weight based on the weight of the toner particles and having a volume-average particle diameter of from 3 to 9 .mu.m; and (b) an external additive; and (ii) a resin-coated carrier having a volume resistivity of from 10.sup.7 to 10.sup.11 .OMEGA..multidot.cm in an electric field of 10.sup.3.8 V/cm and an average particle diameter of from 30 to 60 .mu.m. Also disclosed are a process for forming a black image and a process for forming a full-color image each using the electrostatic-image developer.

Abstract: A dielectric belt 24 is retracted from a photoreceptor 2 before printing, and electrophotographic processes including a process of forming an electrostatic latent image, a developing process and a cleaning process except for a transferring process are repeated. During the repetition of the electrophotographic processes, a surface electric potential in the background of the photoreceptor 2 is measured by the electric potential sensor 10. Alternatively, a quantity of toner adhering to the background of the photoreceptor 2 is measured by the toner sensor 37 and the toner electric charge sensor 36. When the measured values are lower than the reference values, it is judged that no fringe image is generated in the recording condition, and the printing operation is carried out.

Abstract: An image forming apparatus having an image carrying member bearing an electrostatic image wherein the electrostatic image is visualized into a toner image by a developing device. The image carrying member is arranged for transferring the toner image to an intermediate transfer element while the image carrying member and intermediate transfer element are moving at a usual speed corresponding to the speed of movement of the image carrying member during toner image development. Multiple such toner images of different colors may be transferred in this manner to form multi-color images superimposed on the intermediate transfer element for subsequent transfer to a recording medium, usually paper.

Abstract: A color electrophotographic printing system that uses one switched developer power supply for all developers and that enables a reduced size by reducing the interdocument zone. The interdocument zone is reduced by using a developer order in which the last used developers in a development cycle is physically located first. Beneficially, the developer that is used first is physically located last.

Abstract: A system of forming an image on an image transfer medium. The system forms an image according to image data on the image transfer medium and forms one color primer image on the image transfer medium at least in an area of the image. The system forms the image using the transfer medium and can separate the image according to the image data and the primer image from the image transfer medium, and fix the separated image according to the image data and the primer image on a surface of a transferred object by contacting the primer image with a surface of the transferred object. In this system, an expected color image can be obtained even if a transferred object color is not white, because the primer image is formed between the image and the surface of the transferred object.