Abstract: Aligning image transfer assembly belts using two driven image-bearing belts simultaneously engaged with a driven transport belt. Each image-bearing belt conveys image-forming marking material formed thereon, wherein the transport belt is selectively engageable by the two image-bearing belts. The selective engagement of each image-bearing belt being independent from the other, wherein the two image-bearing belts are remote from one another. The method and apparatus also output signals representing at least one detected lateral positions of an edge of a measured belt using at least one edge sensor. The detected lateral position measured can be achieved by one or two edge sensors, wherein the two edge sensors would be disposed remote from one another along an extent across which the edge of the measured belt moves. Then a skew indication of the simultaneously engaged two image-bearing belts is determined based on a the output edge sensor(s) signals.

Abstract: An image forming apparatus performs pseudo gradation processing using dithering, and includes an image carrier; a plurality of light-emitting element arrays arranged in a main-scanning direction and including a plurality of light-emitting elements; an image forming unit performing lighting control of the arrays and forming a pattern image on the image carrier; a detecting unit detecting a density of the pattern image; a position detecting unit detecting a position in the main-scanning direction of the detecting unit with respect to the light-emitting element arrays; a determining unit that, based on the detected position, determines whether the detecting unit is positioned at a proper detection position with respect to the pattern image on which noise has no effect; and an operation control unit that, when the detecting unit is positioned at the proper detection position, performs an image density detection operation on the pattern image using the detecting unit.

Abstract: An image forming apparatus includes toner image forming units that are arranged in a line at two end portions and at an intermediate portion of the line, each of the toner image forming units forming a toner image; an image transfer body to which the toner images formed by the toner image forming units are transferred; pressing members that are linearly arranged so that each of the pressing members faces a corresponding one of the toner image forming units with the image transfer body therebetween, each of the pressing members applying a pressing force to the image transfer body; and a fixing unit that fixes the toner images on a recording member. The pressing forces applied by the pressing members that are disposed at the two end portions are smaller than the pressing force applied by the pressing member that is disposed in the intermediate portion.

Abstract: A method and system for printing image documents using a variety of toners where some toners using a multi-development station having two or more development stations. These toners are co-printed prior to fixing, on the receiver by the multi-development station.

Abstract: In an electrophotographic image forming apparatus employing a contact development system, contact of a development roller against a photosensitive drum is started while forming an electrostatic latent image of a detection pattern for detection in each individual apparatus, and a developed toner image is detected at a predetermined position. At this time, a time from the time when contact of the development roller was started until the time when the toner image was detected is measured, and a delay time from a time when contact operation of the development roller was started until a time of actual contact is calculated by subtracting the time needed until the developed toner image reaches the detection position. The time when contact of the development roller is started is delayed by this time. The same sort of control is also performed for the separation time.

Abstract: A transfer device of the invention includes an endless belt forming a loop-shaped path of movement passing over between a drive roller and an idle roller, a plurality of image bearing members disposed at positions along a direction of movement of the endless belt, and a plurality of transfer members disposed at positions on respective downstream sides of the plurality of image bearing members so as to oppose a plurality of respective image bearing members across the endless belt. The image bearing member disposed on the most upstream side in the direction of movement of the endless belt has a zone of contact in common with the opposed transfer member in the direction of movement of the endless belt. Whereas the other image bearing members do not have any zone of contact in common with the opposing respective transfer members in the direction of movement of the endless belt.

Abstract: A color-image forming apparatus includes a plurality of photosensitive members corresponding to individual colors and disposed along the moving direction of a transfer member to which toner images are to be transferred, wherein the peripheral speed of a photosensitive member that is not forming a toner image on the transfer member is controlled so that a load during forming of a toner image on the transfer member with part of the photosensitive members at least comes close to a reference load generated between all the photosensitive members and the transfer member while all the photosensitive members are forming toner images on the transfer member.

Abstract: By using a black-image forming device, an abrasive pattern is formed on a sheet conveying belt so that toner is input to a contact section where a cleaning blade is in contact with the sheet conveying belt. After the toner is input to the contact section where the cleaning blade is in contact with the sheet conveying belt and then the sheet conveying belt makes one or more revolutions, a process control is performed in which Y, M, and C toner patterns and B toner pattern are transferred onto the sheet conveying belt.

Abstract: A method for calibrating a position of a first register line in a register mark for a multi-color printing machine, said first register line consisting of a first color that does not offer sufficient contrast with respect to a printing material to allow detection above a determined threshold on a register sensor. A plurality of register marks, each consisting of at least one starting line, a background line and a first register line, is printed, said background line consisting of a second color which offers sufficient contrast with respect to the first color for detection above the specified threshold on the register sensor if the first register line is printed on the background line, and said background line having a width that is greater than the first register line, and said starting line, said background line and said first register line being printed with the use of the pre-determined control parameters, which normally cause the first register line to be printed on the background line.

Abstract: An image forming apparatus includes a plurality of optical scanning units to scan light modulated according to an image signal, a plurality of photoconductive drums to form a plurality of electrostatic latent images by the light scanned from the plurality of optical scanning units, a plurality of developing units to develop the plurality of electrostatic latent images formed on the plurality of photoconductive drums into a plurality of toner images, an intermediate transfer unit to transfer the plurality of toner images developed by the plurality of developing units, a plurality of first transfer rollers installed in the intermediate transfer unit to correspond to the plurality of photoconductive drums, respectively, and to apply transfer voltages that is used to transfer the plurality of toner images onto the intermediate transfer unit, a second transfer roller to transfer the plurality of toner images formed on the intermediate transfer unit onto a paper, and a fixing unit to fix the plurality of toner imag

Abstract: A method of registering a print between print stages in a printing system is provided. The method comprises: printing a first part of a digital image on a substrate with a first print engine, wherein the first part of the digital image includes a plurality of reference features; scanning image content on the substrate as it is readied for the second print engine; determining the actual positions of the reference features; using the actual positions of the reference features to determine desired adjustments for the second part of the digital image; applying electronic registration according to the desired adjustments to modify image content of the second print to be aligned with content already on the substrate; and printing a second part of the digital image on the substrate.

Abstract: In the case where a peripheral velocity of photosensitive drums differs from a peripheral velocity of an intermediate transfer belt, the peripheral velocity of the intermediate transfer belt or the peripheral velocity of the photosensitive drums is corrected. The velocity of the intermediate transfer belt is transiently varied in an image forming operation. Accordingly, a plurality of toner patch patterns including toner patches are formed on the intermediate transfer belt, and the difference in peripheral velocity between the intermediate transfer belt and the photosensitive drums is estimated based on a difference between the displacements in the toner patch patterns.

Abstract: An image forming apparatus, forming a color image by successively superposing color images, formed on image carriers of corresponding image forming parts arranged along a rotational direction of an endless moving member, onto the endless moving member or a recording medium conveyed thereby, includes a first part causing a color registration pattern to be created on the endless moving member or the recording medium; a second part obtaining a color registration pattern signal by detecting the color registration pattern; a third part changing image formation timing in the image forming parts based on the color registration pattern signal; and a fourth part causing the endless moving member to rotate in forward and reverse directions after the creation of the color registration pattern. The second part obtains the color registration pattern signal by detecting the color registration pattern during each of the forward and reverse rotations of the endless moving member.

Abstract: A belt transfer device according to the present invention includes an intermediate transfer belt, a transfer member, a shifter, a detector, and a controller. The transfer member primarily transfers a toner image from an image carrier to the intermediate transfer belt. The shifter reciprocates in specified opposite directions so as to shift the transfer member between a transfer position where the transfer member is in compressive contact with the inner surface of the intermediate transfer belt and a home position where the transfer member is away from the belt surface. The detector outputs a signal representing the position of the shifter. Based on the state of the signal output from the detector while the shifter is reciprocating each time in the opposite directions, the controller determines whether the tensile force of the intermediate transfer belt is proper.

Abstract: An image forming apparatus including cyan (C), magenta (M), yellow (Y), and black (K) developing units using a C developer, a M developer, a Y developer, and a K developer, respectively; at least one auxiliary developing unit using a developer other than the C, M, Y, and K developers; a plurality of photosensitive media formed in the C, M, Y, and K developing units and the auxiliary developing unit, respectively; a plurality of cleaning members formed in the C, M, Y, and K developing units and the auxiliary developing unit, respectively, so as to clean surfaces of the plurality of photosensitive media; and waste developer storage units formed in the C, M, Y, and K developing units and the auxiliary developing unit, respectively, so as to collect waste developer cleaned by the plurality of cleaning members.

Abstract: An image forming apparatus includes photosensitive members which are aligned along a conveying direction of a transfer medium and on each of which an electrostatic latent image is to be formed; developing units which supply a plurality of colors of developing agent to the photosensitive members, respectively; and cleaning rollers which slidably contact the photosensitive members to collect at least one of paper powder and developing agent adhering to surfaces of the photosensitive members, respectively. A most upstream cleaning roller which slidably contacts a most upstream photosensitive member in the conveying direction is provided with a paper powder absorption shaft which attracts and absorbs paper powder from the cleaning roller. A most downstream cleaning roller which slidably contacts a most downstream photosensitive member in the conveying direction is not provided with the paper powder absorption shaft.

Abstract: An electro photographic image forming apparatus includes first and second photosensitive bodies, first and second exposing units to form electrostatic latent images on the first and second photosensitive bodies each of which being charged to a uniform electric potential, a first developing unit to develop the electrostatic latent image on the first photosensitive body by supplying a transparent toner thereto, and a second developing unit to develop the electrostatic latent image on the second photosensitive body by supplying color toners thereto, wherein the first developing unit is a developing unit employing a two-component developing technique using a magnetic carrier and a transparent toner.

Abstract: A transfer device includes: an image carrier belt; a first roller around which the image carrier belt is wound; a second roller around which the image carrier belt wound around the first roller and shifted; a first transfer roller contacting the first roller via the image carrier belt; a second transfer roller contacting the second roller via the image carrier belt; and a transfer belt wound around the first transfer roller and the second transfer roller. A width L3 of the image carrier belt and a width L4 of the transfer belt have the relationship of L3>L4.

Abstract: A matched ideal waveform is extracted from a plurality of ideal waveforms based on degree of coincidence with a light sensitive waveform obtained by a light receiving portion. The plurality of ideal waveforms differ from one another in phase. The displacement amount of an image to be formed of an adjustive color from an image to be formed of a reference color is determined based on the extracted matched ideal waveform.

Abstract: An image forming apparatus and corresponding method, the image forming apparatus including a belt member supported by at least two rollers, an image forming member configured to form a patch pattern of image data on a surface of the belt member, a belt supporting member configured to support the belt member on a contact area thereof with respect to the belt member at a position higher than a tangent line of the at least two rollers, and a sensor configured to detect the patch pattern formed on the surface of the belt member at the contact area of the belt supporting member and the belt member.

Abstract: An image forming apparatus includes a belt, plural photosensitive drums that face the belt, plural developing devices that develop plural latent images formed on the plural photosensitive drums using a developing agent, where the developing devices are disposed around the respective photosensitive drums, and plural image forming devices, where each one of the plural image forming devices includes one of the plural photosensitive drums and one of the plural developing devices, and the photosensitive drum of an adjacent one of the plural image forming devices is disposed vertically within a horizontal width of the developing device of one of the plural image forming devices.

Abstract: In an image forming apparatus, an intermediate transfer belt is made of a resin film and is supported by a plurality of rollers. A driving roller that is one of the plurality of rollers, drives the intermediate transfer belt, and also functions as an opposing unit with respect to a secondary transfer roller. The driving roller is made of metal, and applies a bias to at least secondary transfer units, at least at a time of performing primary transfer to a plurality of image bearing bodies.

Abstract: A first correction pattern and a second correction pattern are formed on an endless conveyor belt. The first correction pattern is located ahead of the second correction pattern on the conveyor belt with respect to the direction of movement of the conveyor belt. A sensor detects positional information of the correction patterns. A timing changing unit (controlling unit) changes a detection timing of the second correction pattern from a time point at which the sensor detects the second correction pattern.

Abstract: An image forming apparatus including a plurality of image bearing members, an electrostatic image forming device for forming an electrostatic image on the image bearing members, a plurality of developing devices for developing as developer images the electrostatic images formed on the plurality of image bearing members by using developer charged to a predetermined polarity, a primary transferring device for primarily transferring the developer images borne by the plurality of image bearing members to an intermediate transfer member at a plurality of primary transfer portions, a secondary transferring device for secondarily transferring the developer images primarily transferred to the intermediate transfer member to a recording material at a secondary transfer portion, a cleaning device for cleaning the developer on the intermediate transfer member, and a controlling device for, when a secondary untransferred developer image, which is a developer image that has not been secondarily transferred after the prima

Abstract: An image forming device has image forming units 3-6, a transfer belt 7, a position detection unit 19, a concentration sensor 23, and an adjustment unit. A toner image is formed on the surfaces of the image forming units 3-6, and transferred onto the transfer belt 7. The position detection unit 19 detects a predetermined position on the surface of the transfer belt 7. On the predetermined position, the concentration sensor 23 detects first information relating to the color of the surface of the transfer belt 7. The concentration sensor 23 detects second information relating to the color of the pattern image that is formed on the predetermined position. The adjustment unit adjusts toner concentration at the time of forming an image based on the first information and the second information detected by the concentration sensor 23.

Abstract: An image forming apparatus includes an image bearing member, which rotates and bears a toner image, a thickness of the image bearing member having a periodical variation in a rotation direction of the image bearing member, a first image forming device, which forms a toner image on the image bearing member at a first region with a first toner; and a second image forming device, which forms a toner image on the image bearing member at a second region with a second toner. A distance between a central position of the first region in the rotation direction of the image bearing member and a central position of the second region in the rotation direction of the image bearing member is approximately integer multiples of a periodical length in the periodical variation of the thickness of the image bearing member.

Abstract: A color image forming apparatus includes an intermediate transfer member, a first forming portion having a first transfer unit, a second forming portion provided downstream from the first forming portion, a third forming portion provided downstream from the second forming portion, a fourth forming portion provided downstream from the third forming portion, and a control portion. The control portion controls a bias of at least one of the corresponding developing unit and the corresponding transfer unit, when transfer of the toner image from the intermediate transfer member to the recording medium is completed, so that a toner-image residue toner material resting on the intermediate transfer member is returned to the corresponding developing unit through the image bearing member of at least one of the first to fourth forming portions.

Abstract: In one embodiment, a printing platform is illustrated which includes two or more marking modules offset perpendicular to a process direction to create an aggregate imageable area that is wider than an imageable area of any of the individual marking modules.

Abstract: A fusing device (23) has heat reflectors (238) and (239) positioned in consideration of the fact that convective heat loss from respective outer surfaces of the heat reflectors (238) and (239) depends on orientation of the outer surfaces. More specifically, each of the heat reflectors (238) and (239) are positioned so as to have a convective heat transfer coefficient ? of up to 0.9. The convective heat transfer coefficient ? is given by the following expression: ?=(Su+0.77Sh+0.54Sd)/(Su+Sh+Sd), were Su is a projected area of an outer surface of each of the heat reflectors on an upper horizontal plane, Sh is a projected area of the same on a vertical plane, and Sd is a projected area of the same on a lower horizontal plane.

Abstract: A drum/belt drive starting procedure simultaneous starts the rotation of photosensitive drums and the conveyance of a belt. A drum/belt driving time calculating procedure sets a rotational drive stop time of each photosensitive drum and a conveyance drive stop time of the conveying belt on the basis of a detection result of a reference mark detecting unit. A drum/belt drive stopping procedure stops the rotation of each photosensitive drum and the conveyance of the conveying belt on the basis of a calculation result of the drum/belt driving time calculating procedure. Rotational phase differences of every plural photosensitive drums are set to a predetermined value in the state where rubbing with the belt is small.

Abstract: An image forming apparatus includes an executing portion, which executes a first removing sequence and a second removing sequence when removing a toner image borne on an intermediate transfer member. The first removing sequence passes the toner image through a primary transfer portion, which is applied with a voltage having a same polarity as the predetermined polarity, and thereafter removing the toner image by the removing portion which forms a cleaning electric field. The second removing sequence removes the toner image by the removing portion, which forms the cleaning electric field, without passing the toner image through the primary transfer portion. A selecting portion means selects between the first removing sequence and the second removing sequence in accordance with a toner amount per unit area of the toner image borne on the intermediate transfer member at a stoppage of the intermediate transfer member.

Abstract: An image forming apparatus capable of changing over between black printing and color printing with an intermediate transfer belt being brought into contact with and separated from photoconductors by means of a black transfer member and a three-color-integrated color transfer member. The image forming apparatus has a registration mark former for forming registration marks on the intermediate transfer belt, a registration sensor for reading the registration marks, and a controller for controlling the registration mark former based on the registration marks read by the registration sensor, so as to adjust registration. The controller has an adjustment mode to adjust registration between black and color.

Abstract: An image forming apparatus for performing a printing job using an intermediate transfer belt is provided. The image forming apparatus has a voltage determination part for determining a predetermined level of a refresh charge corresponding to a potential difference which is generated on opposite surfaces of the intermediate transfer belt, and a power supply for supplying the refresh charge to the intermediate transfer belt so that the potential difference is offset. The power supply supplies the refresh charge to the intermediate transfer belt through a certain roller which is in contact with the intermediate transfer belt. Accordingly, the potential difference caused by the polarization in the intermediate transfer belt is offset by the refresh charge, and the variation of the resistance caused by the potential difference is prevented.

Abstract: An image forming apparatus includes a plurality of image forming stations each having an image carrier and forming an image on the image carrier; a mark detecting unit for detecting a plurality of registration correction marks formed on a recording medium by the plurality of image forming stations; a correction mechanism for correcting a position difference between images formed by the plurality of image forming stations in accordance with a detection result by the mark detecting unit; and a controller for independently controlling an image forming operation of each of the plurality of the image forming stations so that the image density of each of the registration correction marks formed by the plurality of image forming units has a different predetermined image density.

Abstract: To provide an image forming apparatus including a first image bearing member, first toner image forming means which forms a first toner image on the first image bearing member, an intermediate transfer member in which a circumferential face is formed, the circumferential face rotates in a predetermined direction by using the center of the circumferential face as a rotating center and the thickness is periodically changed at a predetermined interval in the predetermined rotating direction, a first primary transfer region in which the first toner image on the first image bearing member is transferred to the intermediate transfer member, a second image bearing member and a second primary transfer region in which the toner image on the second image bearing member is transferred to the intermediate transfer member to which the first toner image is transferred, in which the distance between the central position of the first primary transfer region and the central position of the second primary transfer region in th

Abstract: In an Image forming apparatus, a light color toner image forming unit that forms a light color toner image on a transfer medium has a first developing device which develops an electrostatic image on a first image bearing member to form the light color toner image on the first image bearing member. A first transfer member electrostatically transfers the light color toner image to the transferring medium member by abutting against the first image bearing member with the transferring member in a first abutting position. A deep color toner image forming unit that forms a deep color toner image on a transferring medium has a second developing device which develops an electrostatic image on a second image bearing member in a second developing portion to form the deep color image on the second image bearing member.

Abstract: A belt apparatus having an endless belt which is wound around and movably driven by a plurality of support rollers. The speed fluctuations of the endless belt due to the variations in thickness of the endless belt are prevented. A driving apparatus for driving the endless belt has a driving roller and an opposite roller facing with each other across the endless belt, and a driving motor for driving the driving roller, the driving roller and the opposite roller being in pressure contact with each other only at both end parts in their axial direction via the endless belt and the pressure contact part forming a plane.

Abstract: A fixing apparatus according to the present invention includes a flat coil which is arranged along an inside periphery of a heating roller and is supplied with power for heating the heating roller by means of eddy current. At least two flat coils are provided along the inside periphery of the heating roller and have a magnetic field distribution. A release claw is provided at a position where the magnetic field distribution becomes minimum.

Abstract: An image forming apparatus includes a plurality of image forming stations each having an image carrier and forming an image on the image carrier; a mark detecting unit for detecting a plurality of registration correction marks formed on a recording medium by the plurality of image forming stations; a correction mechanism for correcting a position difference between images formed by the plurality of image forming stations in accordance with a detection result by the mark detecting unit; and a controller for independently controlling an image forming operation of each of the plurality of the image forming stations so that the image density of each of the registration correction marks formed by the plurality of image forming units has a different predetermined image density.

Abstract: It is an exemplified object of the present invention to provide an image-forming device that can form a high-quality multicolor image at relatively low cost. To achieve the above object, the inventive image-forming device comprises an endless belt that conveys a recordable medium; plural image-forming units that form a toner layer on the recordable medium via the endless belt; and a fixer that fixes the toner layer on the recordable medium, and a first pressing force applicable to the recordable medium by a last image-forming unit at a downstream side along a direction in which the recordable medium is conveyed among the plural image-forming units is greater than a second pressing force applicable to the recordable medium by another image-forming unit adjacent to the last image-forming unit at the downstream side among the plural image-forming units.

Abstract: Photoreceptor drums for forming color images each have a gear as the drive transmission element at their central shafts. Each gear has an idle gear which in turn is coupled with a first motor via a timing belt. The photoreceptor drum for forming black monochrome images has a gear as the drive transmission element at its central shaft. This gear has an idle gear which is coupled with a second motor.

Abstract: An image forming apparatus having a plurality of image bearing members disposed parallel along a conveying direction of recording sheet and a drive power transmission mechanism that translates movement of a drive source to synchronized and uniform movement of the image bearing members is provided. One embodiment of the drive power transmission mechanism includes a plurality of drive power transmission members and a plurality of intermediate transmission members alternately arranged in groups that are offset relative to each other. The drive power and intermediate transmission members in each group are arranged within a predefined angular orientation to ensure synchronized, uniform movement of the image bearing members and uniform distribution of the toner for each color of the color image being recorded.

Abstract: An apparatus for transferring a plurality of toner images having a charge thereon from a photoconductive member to a receptor sheet, the transferring device including a first corona generator for applying a charge to the sheet of polarity opposite to that of the charge on the corresponding toner image and for transferring the toner image from the member to the sheet, a second corona generator, located after the first corona generator, for applying a charge to the toner image on the sheet of a polarity equal to that of the charge on the toner image for increasing the charge thereof, and a grounding electrode opposite to the second corona generator for electrically grounding the opposite side of the receptor sheet.

Abstract: A color image forming device that can suppress the occurrence of a transfer positional shift due to a variation in velocity of the drive system as low as possible even when the distance between image transfer points of each color varies. In the color image forming device, after a position of a first image transfer point and the position of the second image transfer point are decided so that the distance between the first image transfer point and the second image transfer point is equal to an integral multiple of a reference length corresponding to the velocity variation period of the drive system, positions of image transfer points on the lower side than the second image transfer point are sequentially decided from the upper side of the conveying path according to the following procedures. The temporary position of an i (.gtoreq.3) -th image transfer point is decided.

Abstract: An image forming apparatus has a movable image bearing member, a plurality of developing devices operable for development at different locations along the direction of movement of the image bearing member to develop the image bearing member with toners of plural colors, and a transfer medium carrying member for carrying a transfer medium thereon and conveying the transfer medium to a transfer position. The toner images of plural colors on the image bearing member are superposition-transferred onto the transfer medium carried on the transfer medium carrying member. The transfer medium carrying member is capable of carrying a plurality of transfer mediums at different locations thereon.

Abstract: Specific pattern images are transferred from respective photoreceptors onto the circumferential surface of a transfer belt. By detecting the specific pattern images with sensors, misregistration amounts on a transfer belt are calculated by a misregistration correction control section. Averages of the misregistration amounts for respective colors are calculated for each region that corresponds to a single recording medium placed on the transfer belt. The scanning timings of image writing units are controlled by an image signal output control section based on the calculated averages. As a result, toner images formed on the respective photoreceptors are transferred to proper positions of any recording medium being placed on the transfer belt.

Abstract: The present invention provides an image forming apparatus comprising an image bearing means for bearing an image, a transfer material bearing member for bearing and conveying a transfer material, and a transfer member for transferring the image on the image bearing means onto the transfer material born by the transfer material bearing member, the transfer member being arranged to contact with a surface of the transfer material bearing member opposite to a surface on which the transfer material is born. The transfer member comprises a first layer contacting with the transfer material bearing member and a second layer not contacting with the transfer material bearing member, and the first layer has coefficient of kinetic friction smaller than that of the second layer.