Abstract: According to one embodiment, when performing monochrome image forming, image processing circuits for color image forming, laser control circuits for the color image forming and data processing circuits for the color image forming in an integrated circuit are not operated.

Abstract: A light source device includes a light source, a coupling lens, a first opening plate, a second opening plate, a photoreceptor, a package member, a cover glass, a half mirror, and a light source control device. In relation to a main-scanning corresponding direction and a sub-scanning corresponding direction, divergence angles ?m and ?s of a light beam output from the light source, emission angles ?m1 and ?s1 of a light beam passing through an opening portion A, and emission angles ?m2 and ?s2 of a light beam passing through an opening portion B satisfy relationships |(?m1-?m2)/?m|?0.085 and |(?s1-?s2)/?s|?0.085.

Abstract: A method of correcting print images in an electrophotographic printer wherein an image formed by a print head (3) on a peripheral surface of a photoconductor drum (1) is transferred and printed on a sheet of paper. The method comprises: furnishing the print head with a standard tacho signal in the form of pulses and thereby printing on a sheet of paper a check mark (9) for each given number of pulses of the standard tacho signal while the photoconductor drum makes one rotation; by means of a camera (10), detecting a periodic deviation in each spacing between successive such check marks; in response to the deviation in each spacing between the successive check marks, varying the pulse width of pulses of the standard tacho signal for each spacing between the successive check marks, thereby to provide a modified tacho signal; and effecting printing thereafter based on the modified tacho signal.

Abstract: A driving circuit includes a reference voltage generating circuit and a driver circuit. The driver circuit drives a driven element at a level determined by the reference voltage output by the reference voltage generating circuit. The reference voltage generating circuit includes a regulating section that generates a regulated voltage, a temperature compensation section that applies a temperature compensation to the regulated voltage to compensate for the temperature characteristics of the driven element, and a voltage amplifying section that amplifies the resulting temperature compensated voltage to generate the reference voltage, thereby supplying a reference voltage high enough to avoid noise effects.

Abstract: Restricting a screen line number to prevent degradation in graininess depending on the type of recording paper causes a problem in which the image quality of output matter deteriorates. An image forming apparatus according to the present invention changes an exposure area for one pixel used in image formation in accordance with recording paper in consideration of differences in the influence of the height of toner on graininess depending on recording paper.

Abstract: A light emitting element array that can perform a time-division driving operation with a small number of driving ICs is provided. A light emitting element array chip (1) includes n switch thyristors (S) (wherein n is an integer equal to or greater than 2), n signal transmission lines (GH) connected to N-gate electrodes (d) of the switch thyristors (S) individually, a plurality of light emitting thyristors (T) having N-gate electrodes (b) connected to one of the n signal transmission lines (GH). Anodes (e) of selection thyristors (U) are connected to the N-gate electrodes (d) of the n switch thyristors (S), and N-gate electrodes (f) of the selection thyristors (U) are connected to a common selection signal transmission line (CSL).

Abstract: The exposure apparatus is provided with: an optical member; and a holding member that holds the optical member. Both end portions of the optical member are held by the holding member with a first adhering unit that is cured by light irradiation for first duration and a second adhering unit that is cured by light irradiation for second duration which is longer than the first duration.

Abstract: An image forming device includes an image generating section that generates an image including a plurality of screen types, an image processing section that performs a grayscale screen process on the image and generates grayscale data and screen type data for each pixel, a line head to which the grayscale data for each pixel section is sequentially transmitted, and a light intensity correction circuit that corrects light intensity of each pixel. The image processing section transmits the screen type data for each pixel to the light intensity correction circuit. The light intensity correction circuit transmits a light intensity correction value for each pixel to the line head. The light intensity correction value for each pixel is obtained based on the corresponding screen type data so that pixels of different screen types of the image are corrected in accordance with the corresponding screen types.

Abstract: A method of printing using an image-on-image device that includes a photoreceptor, including monochrome exposing the photoreceptor or monochrome charging the photoreceptor, wherein monochrome exposing the photoreceptor includes charging the photoreceptor, successively exposing the photoreceptor in a monochrome mode using a plurality of exposing devices during a single revolution of the photoreceptor relative to the exposing devices, and developing a monochrome image on the photoreceptor; and monochrome charging the photoreceptor includes successively charging the photoreceptor via a plurality of charging devices during a single revolution of the photoreceptor relative to the charging devices, exposing the photoreceptor using an exposing device, and developing an image on the photoreceptor. A marking device capable of implementing the method of printing.

Abstract: An image forming apparatus includes: an image holder; an exposure member that has an exposure portion exposing the image holder; a first positioning unit that determines a distance in a first direction, which is a direction of an optical axis of the exposure member, between the exposure member and the image holder; and a second positioning unit that determines a position of the exposure member with respect to the image holder in a second direction being a direction of an axis line of the image holder, and a position of the exposure member with respect to the image holder in a third direction being perpendicular to both the first direction and the second direction, and that determines the distance between the exposure member and the image holder at a position substantially closer to the exposure member than the position of the first positioning unit.

Abstract: A method of pixelized image formation on a photosensitive surface, comprising: providing relative motion of the photosensitive surface relative to a multiplicity of light sources, such that pixels on the surface pass a plurality of said light sources; and exposing a plurality of the pixels of the surface to one or more, but fewer than the plurality, of said light sources, such that the exposure of the exposed pixels is the same.

Abstract: An image forming apparatus includes an electrostatic latent image carrier, and an optical writing device including at least one light source, at least one aperture, at least one light shield, a light deflector, an image forming lens, and a housing. The aperture adjusts a light beam generated by the light source into a reference shape. The light shield shields an optical path formed between the light source and the aperture by the light beam. The light deflector deflects the light beam to scan in a main scanning direction. The image forming lens focuses the deflected light beam to scan on the surface of the electrostatic latent image carrier to form an electrostatic latent image on the surface of the electrostatic latent image carrier. The housing contains the light source, the light deflector, and the image forming lens. The housing is integrally molded with the aperture and the light shield.

Abstract: An image forming apparatus in which a plurality of color component images of different colors, which include a reference color (e.g. black) serving as a reference and adjustment colors (e.g. cyan, magenta and yellow) to be adjusted, are formed on respective photosensitive drums and then transferred to a transfer belt. Respective positions of the color component images transferred to the transfer belt are detected by a CCD. Timing adjustment can be performed so that the difference between the detected position of each of the color component images and a prescribed position is not more than a predetermined value, based on the reference color image as the reference. In this case, the color component images are formed on the corresponding photosensitive drums with the same timing by utilizing a single polygon mirror.

Abstract: There is described an apparatus, which includes an image-forming section to form a multicolor image on a recording medium by recording the unicolor images in such a manner that the unicolor images overlap each other, based on printing image data sets of them, and a controlling section that determines at least a sub-scanning velocity in a sub-scanning direction relative to the recording medium, corresponding to a printing magnification factor, so as to adjust an output-start timing in the sub-scanning direction for every printing image data set, in response to the sub-scanning velocity determined in advance. Further, the controlling section also determines a main-scanning velocity in a main-scanning direction, corresponding to the printing magnification factor, so as to adjust output-start timings in both the main-scanning direction and the sub-scanning direction for every printing image data set, in response to the main-scanning velocity and the sub-scanning velocity, both determined in advance.

Abstract: A control part comprises a division location setting part for setting a division location based on an image data; a scan start position setting part for setting scan start positions of recording heads based on the division location; an image data division part for dividing an image data by the division location; and a head movement control part for controlling movement of the recording heads. The division location setting part sets a division location in a blank area having no pixel to be recorded in the primary scanning direction, in the case of publication printing, in a center margin area between page data. Since the recording heads perform scanning concurrently their respective areas that are divided by the division location, no deterioration in image continuity occurs between the recording heads. This permits an image recorder, though having plural recording heads, capable of performing concurrent recordings without loss of continuity.

Abstract: A method and apparatus adjusting the lateral position of an LED bar may minimize image banding in image-on-image systems having multiple LED bar imagers. A photoreceptor may be transported past a plurality of marking stations. At each marking station an LED bar imager extends in a direction perpendicular to the direction of transport of the medium. A mark may be sensed at each station and the lateral position of the LED bar, perpendicular to the direction of transport of the medium, may be adjusted according to the deviation of the position of the mark from a desired position.

Abstract: The present invention provides a tandem-style image forming apparatus that has multiple image forming units and a controller that controls the rotation of the polygon mirrors of the image forming units, wherein during image formation, the controller performs steady rotation control for the polygon mirrors of the image forming units used for image formation, and where a color image forming session is performed after a monochrome image formation session is completed, the controller performs steady rotation control for polygon mirrors of the image forming units used for color image formation but not for monochrome image formation a prescribed period of time prior to the commencement of image formation by such image forming units, thereby extending the useful lives of the motors that drive the polygon mirrors and producing high-quality color images.

Abstract: In a multibeam-type image printing apparatus, a process of adjusting a beam scanning position at which a photosensitive body is scanned is simplified. More specifically, consumption of a developing agent such as toner or the like is suppressed, and the time required for the adjustment process is shortened. A test pattern is formed on the photosensitive body using the first beam out of a plurality of beams, thereby detecting the irradiation position of the first beam with respect to the photosensitive body. Correction data for all the beams are generated on the basis of adjustment data as the detection result and predetermined beam information (information indicating a relative positional relationship between the plurality of beams on the photosensitive body). Image transfer clocks and scanning start positions are set on the basis of the correction data.

Abstract: After measurement, light-emitting elements are temporarily numbered (1), . . . in measuring order and arranged successively on a temporary palette. In parallel with this operation, measured light intensity data are input to a computer system in association with the temporary numbers (1), . . . In the computer system, the measured light intensity data are rearranged according to predetermined algorithm to make the light intensity values of adjacent light-emitting elements substantially equal, so that the temporary numbers (1), . . . are rearranged on a memory in accordance with the rearranged data. The rearranged data are sent from the computer system to a robot, so that the light-emitting elements on the temporary palette are arranged on a taping.

Abstract: An imaging apparatus includes an input that receives a stream of image pixels such as high addressable bits, multiple bits per pixel or binary image bits representing an input image and a processor that processes and directs signals to an LED bar that selectively exposes areas of a photoreceptor. The exposed areas of the photoreceptor form a latent image, controlled by the processor, of areas of varied exposure based on surrounding pixels. The processor examines the pixels to determine an image structure beneficially adaptable to varied exposure and selects a pixel for varied exposure, such as increased or decreased exposure or altered timing to apply the pixel.

Abstract: The present invention relates to a method of reading an image, which comprises exposing a color photosensitive material having at least three photosensitive layers containing blue-, green- and red-photosensitive silver halide emulsions, respectively, on a transparent support, processing the exposed color photosensitive material at a processing temperature of 50° C. or more to form a silver image, and substantially reading the silver image.

Abstract: The invention provides an image forming apparatus comprising at least: an electrophotographic photoreceptor comprising at least a conductive substrate and a photosensitive layer provided on the conductive substrate; a charging device; an exposure device; a developing device; and a transfer device, wherein the exposure device is of a multi beam exposure system which has a surface emitting laser array having two or more light-emitting elements as an exposure light source and which scan the electrophotographic photoreceptor with plural light beams thereby forming electrostatic latent image, and wherein the outermost layer in the electrophotographic photoreceptor, positioned most distant from the conductive substrate, contains a silicon-containing resin containing at least a charge transporting compound or a characteristic group derived from a charge transporting compound, and having a structure in which bonds formed by crosslinking of an O atom with neighboring Si atoms are formed three dimensionally.

Abstract: A light scanning device adjusts scanning speed uniformity with high accuracy to obtain an image having fine absolute position accuracy. The light scanning device is mounted on an image forming apparatus. The light scanning device includes a scanning speed uniformity adjusting mechanism that can move a reflection mirror around the axis that is orthogonal to a main scanning corresponding direction and parallel to a reflection surface of the reflection mirror. The light scanning device further includes a scanning line inclination adjusting mechanism that can move an optical element around the axis orthogonal to the main scanning corresponding direction and orthogonal to the sub-scanning corresponding direction. The optical element has a function of adjusting a scanning line position.

Abstract: An 8-bit (256 gradient) image is represented using a driver IC of 6-bit (64 gradient) construction to drive a plurality of arrayed optical shutter elements. The image data are divided into 64 gradient sections, synchronized by shift clock signals, and transmitted in four cycles to the shift register. The optical shutter element is not turned OFF at the 64th pulse, but is continuously driven without transmitting to the comparator the standard clock signal of the 64th pulse, which controls the ON time of the optical shutter element. In this way, an image of a higher number of gradient levels can be represented using a driver IC of a low number of bits, thereby providing a solid state scanning type optical recording device which suppresses noise generation by reducing the load on the driver IC when driving at multi-level gradient.

Abstract: The present invention provides an image forming method comprising the steps of exposing imagewisely an image forming material having a photosensitive layer comprising an infrared absorbing agent, a polymerization initiator and a polymerizable compound on a substrate to overlapping infrared beams. The solubility of the photosensitive layer in an alkali developing solution reduces upon exposure to light of wavelengths in the range of 750 nm to 1400 nm. The exposed image forming material is developed, and the infrared beam diameter used in light exposure is 20 &mgr;m or less, and the overlapping coefficient is 0.8 or more.

Abstract: A device sets the focus of at least one exposure head on a recording material, in particular a printing plate, in an exposer for recording printing originals. An exposer has an exposure drum for holding the printing plates, and an exposure-head carrier, which contains a carrier plate for holding exposure heads, and a carrier base. The carrier plate and the carrier base are connected such that they can move by a hinge which is disposed on the front side of the exposure-head carrier, facing the exposure drum. The rear of the carrier plate is raised or lowered by a tilting drive, as a result of which the exposure heads are moved jointly and substantially radially toward the exposure drum or away from the exposure drum. The hinge is preferably formed from at least one spring plate.

Abstract: An image forming apparatus having: a print head provided with plural recording elements arranged in an array, each of the recording elements being operated based on respective correction coefficient of light amount; and an image reading apparatus for reading an image; wherein, an image for correction is recorded onto the photosensitive material by the print head, read information D (i) of the image for correction is acquired (where, “i” is a number indicating an order of each recording element) by the image reading apparatus, a correction amount C (i) for a recording characteristic of each recording element is acquired based on the read information D (i), and an image is recorded by using the correction amount C (i); wherein, the correction amount C (i) is acquired by using the read information D (i) and read information D (k) (where, “k” is a different number from “i”).

Abstract: In an image forming apparatus, unnecessary light emitted from a light source is irradiated to a solar battery panel in printing or reading an image, and in a standby state. The solar battery panel is provided inside of a light-quality adjusting unit or a balance filter unit, and also provided in a surface to which the light from the light source is irradiated. The solar battery panels are arranged so as to cover gaps: the gap generated between the light-quality adjusting unit or the balance filter unit and the discussion box and the gap generated between the diffusion box and the film carrier. The solar battery panel converts the light from the light source to the electricity. The electricity is charged in a battery to drive a cooling fan.

Abstract: The invention provides an image forming apparatus comprising at least: an electrophotographic photoreceptor comprising at least a conductive substrate and a photosensitive layer provided on the conductive substrate; a charging device; an exposure device; a developing device; and a transfer device, wherein the exposure device is of a multi beam exposure system which has a surface emitting laser array having two or more light-emitting elements as an exposure light source and which scan the electrophotographic photoreceptor with plural light beams thereby forming electrostatic latent image, and wherein the outermost layer in the electrophotographic photoreceptor, positioned most distant from the conductive substrate, contains a silicon-containing resin containing at least a charge transporting compound or a characteristic group derived from a charge transporting compound, and having a structure in which bonds formed by crosslinking of an O atom with neighboring Si atoms are formed three dimensionally.

Abstract: An image forming apparatus, which includes a plurality of image forming portions transferring a yellow image, a magenta image, a cyan image, and a black image formed on a plurality of photoconductor drums to a sheet conveyed on a conveying belt, a marking unit forming marks on the conveying belt, a detecting unit detecting the marks with three or more sensors aligned in a direction normal to a direction in which the sheet is conveyed, a calculating unit calculating an amount of color misalignment in accordance with results detected by the detecting unit, and a correcting unit correcting the color misalignment in accordance with the calculated amount of color misalignment, wherein the calculating unit calculates an amount of skew difference in accordance with results detected by two sensors among the three or more sensors, wherein one sensor of the two sensors is disposed on one end of the three or more sensors and the other sensor of the two sensors is disposed on the other end of the three or more sensors, w

Abstract: In this invention, the relationship between the attachment position of a sensor and the formation positional shift of a color image is checked by moving a color misregistration detection sensor along an attachment position candidate line that is defined in advance in a direction perpendicular to the rotational direction of an endless-belt-shaped transfer body. A specific attachment position on the sensor attachment position candidate line, at which color misregistration of the color image at a side edge portion of the transfer body becomes equal to the maximum value of color misregistration at a portion except the side edge portion, is found. The sensor is fixed at a position that satisfies the specific attachment position and opposes the color image formation surface of the transfer body. Accordingly, the image forming apparatus is controlled to correct color overlay on the basis of the detection signal of the color image by the sensor.

Abstract: An optical system for an image forming apparatus which a first light source for selectably emitting a plurality of image forming light beams based upon control signals and a second light source for emitting image forming light beams of a number of less than that of said first light source. The first light source of the optical system selectably emitting multiple light beams and a single beam, e.g. selectably emits two beams and a single beam.

Abstract: An image forming apparatus for sequentially superimposes images formed by a plurality of image forming stations for forming images of different colors, respectively, on a transferring material born and transported by a transferring material transporting member, which forms a misregister detection mark on the transferring material transporting member, illuminates to read the mark, calculates a misregister amount of the read misregister detection mark, and corrects the misregister of an image based on calculated results, wherein the apparatus adjusts an illuminating light amount according to a color of a misregister detection mark.

Abstract: A flat-type fluorescent lamp is used as a light source of a color thermal printer. The flat-type fluorescent lamp has a yellow luminescent surface for emitting yellow fixing rays, and a magenta luminescent surface for emitting magenta fixing rays. The respective luminescent surfaces are disposed back to back and are selectively activated by a lamp driving circuit. The flat-type fluorescent lamp is rotatable between a first position where the yellow luminescent surface confronts a recording surface of a color thermosensitive recording paper, and a second position where the magenta luminescent surface confront the recording surface of the recording paper.

Abstract: Color imaging methods and systems are provided where each color separation image is to be registered in a composite manner under a variety of machine conditions. Registration sensors are provided to register the color separations under a variety of machine conditions while accounting for the different types of registration sensors used. A controller calibrates the registration sensors automatically based on set-up data and, using the calibrated sensors, controls the output of the image data for one or more of the color separation images to reduce or eliminate image registration offsets. The registration sensors are calibrated by directly measuring set-up marks during set-up. Each registration sensor outputs a feedback to the controller during set-up to account for phenomenon caused by variation in toner concentration or sensor susceptibility. The registration sensors provide a plurality of set-up sensor feedback values, one for each of at least four colors and one for a bare photoreceptor belt.

Abstract: Optical systems are disposed in the two symmetrical direction with respect to an optical deflector, and direct the optical beams deflected by the optical deflector into respective surfaces to be scanned, and forming images thereon. A housing encloses a plurality of light sources, optical deflector and optical systems, the housing includes a base plate on which the optical deflector and optical system, and a side wall surrounding the base plate; the base plate divides the housing into two sections; the plurality of light sources are disposed on the side wall; and optical components of the optical systems are distributed into the two sections of the housing.

Abstract: An intermediate belt made of an endless belt is provided by 45 degrees inclined horizontally and looped over two rollers at both its ends, and four photosensitive drums are provided in contact with the top surface of this intermediate belt. A reflection mirror is provided over each photosensitive drum, and a single polygon mirror is provided on almost the same level as these reflection mirrors. The polygon mirror is provided on the side of the reflection mirror of which optical path to the corresponding photosensitive drum is the longest so that the optical path lengths from the polygon mirror to the respective photosensitive drums are equal to each other.

Abstract: An image forming apparatus for forming an image on a recording material includes a photosensitive member, an array of light emitting elements for exposing the photosensitive member in accordance with an image information, and a developer for developing pixels exposed by the ray of light emitting elements, wherein the array of light emitting elements further emit a light during a time period other than a time period during which the array of light emitting elements emits a light in accordance with the image information.

Abstract: An optical scanning apparatus is configured to comprise (a) a deflector for deflecting and scanning a plurality of bundled incident laser beams, (b) a conversion optical system for converting the bundle of laser beams moving at a constant angular velocity into a bundle of laser beams moving at a constant linear velocity, (c) reflection mirrors for separating the bundled laser beams into four corresponding to respective colors, (d) photosensitive members for forming respective electrostatic latent images by means of the laser beams corresponding to the respective colors, wherein one of the photosensitive members is disposed on a plane parallel to an area defined by the laser beams traveling between the deflector and the conversion optical system and (e) a correction optical system for correcting curvatures of field with respect to the respective laser beams and leading the laser beams to the photosensitive members.

Abstract: Optical systems are disposed in the two symmetrical direction with respect to an optical deflector, and direct the optical beams deflected by the optical deflector into respective surfaces to be scanned, and forming images thereon. A housing encloses a plurality of light sources, optical deflector and optical systems, the housing comprises a base plate on which the optical deflector and optical system, and a side wall surrounding the base plate; the base plate divides the housing into two sections; the plurality of light sources are disposed on the side wall; and optical components of the optical systems are distributed into the two sections of the housing.

Abstract: A xerographic printer includes a rotatable photoreceptor which is exposed, with each cycle, by a regular exposure device to create an image desired to be printed. Elsewhere along the photoreceptor is disposed a supplemental discharge device which discharges only those small areas on the photoreceptor which were not discharged by the regular exposure device within the cycle. In this way, every small area of the photoreceptor is evenly discharged within each cycle, and thus every small area of the photoreceptor experiences the same amount of aging. The system is particularly useful for full-color xerographic printers, in which the photoreceptor is repeatedly discharged by different exposure devices within each cycle.

Abstract: An image forming apparatus is provided which includes an image carrying member, a plurality of charging devices for charging the image carrying member, a plurality of laser exposing units for scanning the charged image carrying member with laser beams so as to form latent images at a predetermined position on the image carrying member, a plurality of developing devices for developing the latent images so as to form toner images, and a transfer section for transferring the toner images onto a sheet. The plurality of laser exposing units are vertically arranged and fixed to each other as a single body so that each laser beam of the laser exposing units is parallel to another laser beam with a predetermined interval.

Abstract: An image forming apparatus includes a photosensitive member, an exposure device includes a single-chip light emission element array formed by integrating a plurality of light emitting elements in a single chip which exposure device executes the exposure in the main scanning direction relative to the movement of the photosensitive member, by the light emission from the single-chip light emission element array, and a developing device provided around the photosensitive member.

Abstract: The image processing circuit essentially includes an image data input portion, an image processing portion, an image data output portion, an image memory composed of a hard disk drive etc., a central processing unit (CUP), an image editing portion, an external interface portion. Based on the determination result of the laser recording status determination by the CPU, an LCU also serving as a mirror motor control device, stops or retards the drives of driving motors, one by one, in the order of their completion of laser recording. The image processing circuit may further has a mode manager for checking the usage frequencies of the first most processing mode in which the input image information is image processed as color image information and the second processing mode in which the input image information is processed as monochrome image information. Moreover, the image processing portion may further has an original discriminating portion for determining the color type of an original.

Abstract: A multi-laser scanning unit (LSU) in which scanning lines incident parallel onto a photoreceptor have the same scanning direction. The multi-laser scanning unit includes: a driving source for providing a rotatory force; a deflection disk installed around a rotary shaft of the driving source having a plurality of sectors each with a hologram pattern for diffracting and deflecting incident light, for scanning light through rotation; a plurality of light sources installed facing one surface of the deflection disk for irradiating a plurality of light lines onto predetermined points of the deflection disk; and a light path changing portion for changing traveling paths of the plurality of scanning lines formed by the rotation of the deflection disk, wherein the plurality of light sources are arranged such that two incident points which are the farthest from each other among the plurality of incident points formed on the deflection disk form 180° with the center point of the deflection disk.

Abstract: A laser printing process using a rotary light sensitive roller electrically charged by points by a laser beam and intended for receiving onto the charged points particles of a toner powder and then transferring the same onto a band to be printed, includes a first step wherein the image to be printed is stored, by a first laser beam coming from a first laser source controlled by a computer, onto a rotary memory roller whose surface is covered with a layer of a material capable of assuming either an amorphous or a crystalline structure, this structure being convertible under the action of a laser beam, and this material showing a high difference in reflecting ability according to whether it assumes the one or the other of its structures, and includes a second step wherein the thus stored image is transferred, by the optical reflection of a second laser beam coming from a second laser source having in its whole a linear character, onto the light sensitive roller intended to receive the toner and to transfer the

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: In a beam scanning apparatus of an electrophotographic color printer, at least two beam deflectors, each having a deflection disk consisting of at least two sectors and a driving source for rotating the deflection disk, deflect and scan an incident beam. The deflection disk has a pattern formed thereon for diffracting and scanning the incident beam. A plurality of light sources, arranged between the beam deflector and a photoreceptor, emit light to the deflection disk. A beam path changing unit changes a proceeding path of the beam deflected by the respective beam deflectors to proceed toward the photoreceptor. A beam correcting unit, arranged between the respective beam deflectors and the photoreceptor, corrects the input beam having its path changed by the beam path changing unit.

Abstract: In this digital color copier, laser beam scanner units of the same configuration are arranged in parallel with each other, and all are controlled in a unified manner by a laser control unit provided outside the units. In order to synchronously rotate the polygon mirrors in a precise manner, the speeds of rotations of their motors, fed back from tacho-generators are compared to the reference frequency generated from an oscillator so as to allow a motor control circuit to control the driving motors of the polygon mirrors. Further, the BD signals from beam detectors (BD) are fed back to the laser control unit so that all the BD signals from the laser scanner units for black and the three colors can become synchronized with each other, thus enabling control of the polygon mirrors.

Abstract: A color image forming apparatus includes: a rotary image forming body; a plurality of charging units provided along the image forming body for charging the image forming body; a plurality of exposure units each provided inside the image forming body for imagewise exposing the image forming body to form a latent image; a plurality of developing units each storing therein colored developer different from each other, provided along the image forming body, for developing the latent image formed on the image forming body to form a colored toner image different from each other. After a plurality of different colored toner images are superimposed on the image forming body through successively repeating of charging by the charging unit, imagewise exposing by the exposure unit and developing by the developing unit to form a colored toner image during one rotation of the image forming body, the superimposed toner images are collectively transferred onto a transfer member.