Abstract: A color image forming method, including the steps of: charging a front surface of a photoreceptor; conducting image wise exposure onto the charged front surface from a rear surface of the photoreceptor so that a latent image is formed on the front surface; developing the latent image with a color toner so that a color toner image is formed on the front surface; and repeating the steps of charging, conducting image wise exposure and developing so that a multicolor toner image is formed on the front surface; in which a secondary color of the multicolor toner image, which consists of two color toner images, is formed in a manner that the two color toner images are formed by conducting the image wise exposure at a same exposure amount; and the first one of the two color toner images is formed by conducting the image wise exposure at an exposure amount which creates a potential smaller than that of already formed primary color of the multicolor toner image, which consists of single color toner image.

Abstract: The object of the invention is to provide a small-size image forming apparatus in which a plurality of light emitting element arrays are easily aligned with each other at high accuracy. Each of light emitting element arrays of Y, M, C, K comprises a plurality of LED elements arranged in a straight line and is driven by a color image signal of each color. On the reference plate disposed on the support are arranged head substrates having light emitting element arrays of each color in such a manner that the light emitting element arrays are nearly in parallel with each other. On a peripheral surface of each photosensitive drum, an electrostatic latent image forming position is established where an electrostatic image is formed by receiving light from each of the light emitting element arrays, and toner of the specified color is supplied to the specified electrostatic latent image forming apparatus by each developing device.

Abstract: The present invention provides a color image forming apparatus comprising a plurality of color recording heads each having a plurality of recording chips for effecting the recording in response to an image signal. Features of the recording chips attached to the recording head for forming a yellow image differ from features of the recording chips attached to the other color recording heads.

Abstract: In a color image forming apparatus provided with a photoreceptor having a rotatable peripheral surface; plural sets of a charging device, an imagewise exposure device, and a developing device, each set of the plural sets is provided separately from other sets around the peripheral surface of the photoreceptor so that plural color component images are formed one after another by the plural sets and are superimposed so as to form a color image on the peripheral surface during a single rotation of the peripheral surface. The developing device has a casing and the imagewise exposure device and the developing device of each set are arranged such that a portion on the peripheral surface locating at an imagewise exposing position moves into the casing of the developing device before the electric potential V1 of the portion is lowered to the half of V1 (V1/2).

Abstract: An exposure head wherein a light-shielding panel having enclosing openings capable of receiving individual LED chips, and a front surface panel having small openings are disposed at a front surface of an LED panel in which the LED chips are arranged, is provided. In the exposure head, the LED chips and bonding wires can be housed in the enclosing openings, and can be protected from a medium to be exposed, by the front surface panel. Therefore, each dot can be irradiated with exposure light from the LED chips, which are disposed close to the photosensitive medium, so that each dot can be exposed without using a lens system. The inside surfaces of the enclosing openings are made reflective to prevent exposure light from leaking from the cells in which the individual LED chips are housed, into other LED chip cells, so that each dot can be exposed to high-intensity exposure light.

Abstract: In an image forming apparatus, an image is formed pixel by pixel for each image data on a photoreceptor, wherein each pixel has a maximum recording width. A plurality of light emitting elements are aligned in an array form and each light emitting element is mounted with a setting width, wherein each light emitting element has a mount-shaped light amount distribution curve in which light amount data spread to both sides of a peak corresponding to the maximum light amount. Each pixel is divided into plural small pixels. Each small pixel is provided with a light emitting element so that an image is formed in the maximum recording width of each pixel by plural neighboring light emitting elements in accordance with image data of each pixel, wherein the image forming width at the light amount of 50% of the maximum light amount of each light emitting element is wider than the setting width of the light emitting element and is narrower than the maximum recording width of each pixel.

Abstract: A color copy machine is equipped with four image forming sections for forming images of different color components based on image data items relating to separated color components. A conveyance belt is provided below each image forming section. To avoid forming of a displaced image on a recording paper sheet P conveyed by the conveyance belt, pattern data for prevention of a displaced image is synthesized with image data. Each image forming section forms color patterns on predetermined portions of the conveyance belt on the basis of the synthesized data. The main-scanning directional displacement of each color pattern can be detected by comparing the numbers of those sensed line segments of the patterns which are sensed by a sensor. Then, the image forming positions are adjusted so that the numbers of the sensed line segments will be equal to each other.

Abstract: An improved method of electrophotographic color printing in which only a single pass of a drum or belt is needed for formation and transfer of the toner image onto a desired medium by utilizing a transparent drum or belt for the supportive member for the photoconductive material, and exposing from the inner side of the drum or belt. The invention includes, among others, a method of synchronous laser-beam exposure that provides improved registration of images, methods of exposure for small diameter drums, a method to achieve a longer-lived drum or belt, an improved fusing method, methods of improving the toning process, and methods to achieve an improved image quality.

Abstract: An electrostatographic reproduction method and apparatus includes an electrostatic recording member moving in a process direction. A plurality of recording elements on a writer imagewise expose the recording member to form electrostatic latent images on the recording member. The writer includes driver circuitry for actuating selected recording elements. The exposed recording member is then moved through a development station to develop the latent images. The developed images are transferred to a record member. An operator selectable adjustment controller is manually adjusted for generating adjustments in operation of the recording elements to compensate for a misalignment of a process station in the apparatus.

Abstract: An image forming apparatus includes a moving member for conveying a recording member on which an image is to be formed, image forming units for forming marks for detection of a position of the image on the moving member, an illuminating device for illuminating the marks for detection of the position, which includes a LED light source, a detecting device for detecting the marks, and a control device for controlling the image forming units with detection signals detected by the detecting device.

Abstract: A single pass ROS system provides a plurality of latent images which may subsequently be developed in different colors. The ROS units are initially aligned so that each color image is precisely registered at the same relative position along the exposed area of a photoreceptor belt. The alignment is accomplished by forming a pair of opposed alignment apertures in the surface of the belt and detecting coincidence or lack of coincidence of signals generated by the beginning and end of each scan line. The correction is enabled by rotating the output window in the ROS system, a transmissive optical component with no optical power, subsequent to the ROS, to create the required rotation of the projected scan line. Once the initial X and Y-axis alignments are complete, subsequent alignment is maintained through subsequent passes by checking the positions of the previously identified pixels as they advance past additional lead edge apertures formed in the process direction along the belt surface.

Abstract: The present invention is directed to a precise method of registering a plurality of ROS imagers, so as to form sequential registered images on a photoreceptor belt in a single pass. Pairs of belt holes are formed in the photoreceptor belt, outside the image area and outside of the scan width of the ROS imagers. A pair of light sources are incorporated into the post polygon optics of each ROS imager so as to produce a light spot at the photoreceptor surface which will periodically illuminate the holes on the belt. As the leading edge of the belt holes advances into the beams, detectors placed beneath the belt and beneath the exposure station provide signals representing the exposure level of the light source output. The position of a transmissive optical element with no optical power, subsequent to each of said ROS imagers, is adjusted in response to registration error signals generated by said photodetecting means to adjust the position of said scan lines.

Abstract: Full color, two-pass imaging process using black, magenta, cyan and yellow toners and Non-Interactive Development (NID) without fringe field development. A switchable wavelength flood lamp structure is provided for producing blue and red light. One wavelength is used during the first pass of a photoreceptor through various processing stations for revealing an imagewise voltage for development with magenta toner using an NID system. The other wavelength is used during a second pass of the photoreceptor for revealing another imagewise voltage to be developed with magenta toner.

Abstract: An electrophotographic printer includes a plurality of recording heads connected in series in a closed cooling circuit. Each of the recording heads includes a linear array of light-emitting diodes (LEDs) on a common thermally conductive LED carrier bar. The carrier bar carries a series of modules, each module containing N LEDs with their associated drivers. The carrier bar is provided with a U-shaped duct inside a thermally conductive body which is in thermally conductive contact with the carrier bar. The duct extends between a fluid inlet and a fluid outlet and has a cooling fluid such as water flowing therethrough.

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

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 processing apparatus includes a plurality of image reading units, each of which reads an original image and produces a color image signal, a color image recording unit which records a color image in accordance with the color image signal, and a correction unit provided for each of the plurality of image reading units to correct the color image signal such that each image reading unit has the same overall spectral sensitivity characteristics.

Abstract: Corrected recording data for a present pixel are generated from recording data stored in an image memory based on recording data for pixels preceding, following, above, and beneath the present pixel, and stored in a corrected image memory. A laser diode is energized according to the corrected recording data to output a laser beam for thereby recording an image on a thermosensitive recording medium. Since the recording data have been corrected taking into account the thermal energy from the adjacent pixels, the image thus recorded on the thermosensitive recording medium is highly accurate at a high speed.

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.

Abstract: A single pass EP color printer includes a photoreceptor web having multiple layers and including a charge transport layer and a charge generation layer. Four exposure devices (e.g. either laser-based or thin film electroluminescent edge emitting (TFEL) devices) are serially arrayed along the photoreceptor web and act to expose the photoreceptor web in accordance with cyan, magenta, yellow and black color image pixel data. A liquid toner developer module is associated with each exposure device and includes a liquid toner reservoir, a developer roll for carrying the liquid toner to a transfer point and a squeegee roll. Each developer module is fixed so as to position its developer roll at a constant prescribed distance from the photoreceptor web at the toner transfer point and to create a fluid interfacial layer between its developer roll and the photoreceptor web. In addition, each squeegee roll is maintained in constant contact with the photoreceptor web.

Abstract: A belt driving apparatus for carrying material to be recorded to a plurality of image recording units. In the belt driving apparatus, the distance of movement of material to be recorded corresponding to one rotation of the belt driving roller has been set to n (an integer)-times (where n=2, 3, 4 . . . ) as long as a distance between each image recording unit. A distance between one image recording unit and another recording unit is equal to or an integral fraction of .pi.(D+2 t), wherein D is the diameter of a drive roller driving the belt and t is the thickness of the belt.

Abstract: A multicolor image forming apparatus for forming a multicolor image on a transfer material includes a mechanism, in which when forming a plurality of color toner images on a single electrostatic-latent-image bearing member performing endless movement, deviation is not produced between the respective color toner images. The distance between first and second latent-image forming portions on the electrostatic-latent-image bearing member is arranged to equal an integer multiple of the moving distance of the electrostatic-latent-image bearing member caused by a single revolution of a driving roller for driving the member.

Abstract: A single pass color xerographic printing system with a single polygon, single optical system Raster Output Scanning (ROS) system has a dual wavelength laser diode source for the ROS which images the dual beams at a single station as closely spaced spots on a dual layer photoreceptor with each photoreceptor layer sensitive to or accessible by only one of the two wavelengths.

Abstract: A method and means for compensating for lateral registration errors in printing machines of the type having a plurality of image processing stations for forming a composite image on an imageable surface which moves relative to the stations. The invention includes monitoring means for determining the angular displacement of the surface from a reference in the process direction to thereby determine the lateral registration error at each of the image processing stations. Actuating means are provided to move the image processing stations laterally relative to the surface to provide lateral registration of the images formed on the surface.

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: A color image processing apparatus includes a plurality of image reading units, each of which reads an original image and produces a color image signal; a color image recording unit which records a color image in accordance with the color image signal; and a correction unit provided for each of the plurality of image reading units to correct the color image signal such that each image reading unit has the same overall spectral sensitivity characteristics.

Abstract: The present invention is directed to a precise method of registering a plurality of ROS imagers, so as to form sequential registered images on a photoreceptor belt in a single pass. Pairs of belt holes are formed in the photoreceptor belt, outside the image area and outside of the scan width of the ROS imagers. A pair of light sources are incorporated into the post polygon optics of each ROS imager so as to produce a light spot at the photoreceptor surface which will periodically illuminate the holes on the belt. As the leading edge of the belt holes advances into the beams, detectors placed beneath the belt and beneath the exposure station provide signals representing the exposure level of the light source output. The detectors produce a current output representative of the exposure level. The current output is converted into page sync signals which are reproducible through each of the imaging stations to produce registration of the first scan line of each image sequence.