Abstract: An image reading device includes a conveying unit, reading unit, detecting unit, and control unit. The conveying unit conveys two sheets of the original one by one. The reading unit reads a sheet passing past a reading position. The detecting unit detects a sheet passing past a detection position upstream of the reading position in a conveying direction. The control unit controls the reading unit to start a reading process when a leading edge of sheet reaching a position upstream of the reading position by a first distance, controls the reading unit to stop the reading process when a trailing edge of sheet reaching a position downstream of the reading position by a second distance, determines an interspace between the trailing edge of sheet and a leading edge of a subsequently-conveyed sheet, and updates the first distance and the second distance based on the interspace.

Abstract: A medium transporting device includes: a transporting path; a contacted member that is provided on the transporting path to be movable in a medium width direction orthogonal to a medium transporting direction; a line-up member on the transporting path that lines up a position of the medium by sending the medium transported on the transporting path to the contacted member to bring the end of the medium in the medium width direction into contact with the contacted member; a displacement amount calculation unit that sets on a downstream side of the line-up member in the medium transporting direction, and calculates a misregistration amount of the medium in the medium width direction; and a contacted position control unit that controls a position of the contacted member by moving the contacted member in a direction of reducing the misregistration amount.

Abstract: There is provided an image processing apparatus which can suppress degradation of an image quality in a recording material save mode processing and obtain an effect of consumption amount reduction of recording material desired by a user at low costs. A recording material consumption amount at the time of applying first color conversion processing unit is predicted corresponding to inputted image data. The setting of a second color conversion processing is changed from a prediction value and a target value of the recording material consumption amount.

Abstract: A first conveyance path is a path for conveying paper from a paper feed unit to a registration roller. Passage of paper on the first conveyance path is detected by a first sensor and a second sensor. The first sensor detects passage of paper upstream from the second sensor. A second conveyance path is connected to the first conveyance path downstream from a detection position of the second sensor. In response to the first sensor detecting passage of paper, first preregistration correction is performed. In response to the second sensor detecting passage of paper, second preregistration correction is performed. If a first sheet of paper is supplied from the paper feed unit, the first preregistration correction is performed on a second sheet of paper conveyed following the first sheet. If the first sheet is conveyed from the second conveyance path, the second preregistration correction is performed on the second sheet.

Abstract: An image forming apparatus includes: a first image carrier; a first image forming unit that forms an image; an intermediate transfer belt; a primary transfer unit that primarily transfers the image onto the intermediate transfer belt; a secondary transfer unit that secondarily transfers the image transferred further onto a recording medium; a second image carrier that transfers the image onto the recording medium; a second image forming unit that forms an image on the second image carrier; a direct transfer unit that directly transfers the image onto the recording medium; a recording medium carriage belt, and a driving roller that drives the recording medium carriage belt; a speed fluctuation detecting unit; and a drive control unit that controls driving of the driving roller so as to reduce the cyclic speed fluctuation of the carriage belt based on a detection result of the speed fluctuation detecting unit.

Abstract: According to the present invention, skew feeding of a sheet is corrected while conveying the sheet, positioning of a side edge of the sheet in the width direction is carried out, and an image is formed on the sheet by an image forming portion 90. Two steering mechanisms 120a and 120b are disposed upstream of the image forming portion along the conveying direction, and the steering mechanisms 120a and 120b can feed a sheet on the skew in any direction with respect to the sheet conveying direction. Two CISs 100a and 100b are disposed along the sheet conveying direction corresponding to the steering mechanisms. A skew feeding angle and a skew feeding velocity of each of the steering mechanisms is changed according to differential value between a side edge position detected by the CISs 100a and 100b and a target position of a side edge of a sheet.

Abstract: A method for automatically adapting a write cycle to a movement of a web-shaped medium in a digital printing machine, as a function of the thickness of the web-shaped medium guided around first and second transport or guide rollers, includes providing the first and second transport or guide rollers having a known diameters, the diameter of the second being different from the diameter of the first. A rotational speed ratio N(T) between the first and second transport or guide rollers (9, 11) is determined while the printing material (6) is guided around the transport or guide rollers (9, 11). The write cycle is determined at least with the use of the previously determined rotational speed ratio N(T).

Abstract: This disclosure provides systems and methods for decoupling the mechanical drive systems of image scanners from the exposure system. A light source, such as an array of light-emitting diodes (LEDs), may be modulated in order to maintain a constant exposure for each scan-line, regardless of the document velocity. Accordingly, the present systems and methods allow for continuous document scanning at varying speeds. An automatic document feeder may dynamically adjust the velocity of a document without negatively impacting the exposure of the image scan. As the velocity of the document is changed, the modulation rate of the light source may be adjusted to maintain a constant exposure.

Abstract: An image reading device includes a transporter transporting a document to a reading position, a first corrector correcting a skew of the document by coming into contact with a leading edge thereof, a radiating unit radiating light to the document, an image-information acquiring unit acquiring image information of the document based on information of light reflected therefrom, a reflector reflecting the radiated light, a leading-edge detector comparing a quantity of light reflected by the reflector with a quantity of light reflected by the document so as to detect the leading edge, a skew-amount calculator calculating a skew amount of the leading edge, and a second corrector correcting a skew of the image information based on the skew amount. The device switches between the skew correction by the first corrector and the skew correction by the second corrector based on document information, the skew amount, or user's selection.

Abstract: An image forming apparatus includes an image forming unit forming an image on a first recording medium based on image data, a measurement unit being positioned in an immediate vicinity of the image forming unit, being arranged upstream of a sheet-conveyance path than the image forming unit, and measuring a size of the first recording medium, an expansion ratio calculation unit calculating an expansion ratio of the first recording medium based on a first size of the first recording medium obtained before the first recording medium is passed through the image forming unit and a second size of the first recording medium obtained after the first recording medium is passed through the image forming unit, and a correction unit correcting the image data used for forming another image on a second recording medium conveyed after the first recording medium based on the expansion ratio.

Abstract: An image forming apparatus includes an image forming unit that forms an image on a recording medium; a width detector that detects positions of side edges of the recording medium in a width direction, which is orthogonal to a conveying direction in which the recording medium is conveyed, at multiple detection positions along the conveying direction; a shape calculator that calculates angles between the conveying direction and straight lines each connecting the positions of the same side edge detected at the multiple detection positions and calculates a shape of the recording medium based on the angles; and a correction unit that corrects image data of the image to be formed by the image forming unit based on the calculated shape of the recording medium.

Abstract: An image forming apparatus can form a high-quality image without a toner image being rubbed with and transferred onto a sheet.

Abstract: Embodiments described herein are directed to registering media in a duplex printing system. A first side of a sheet of media is registered in a first pass in response to detection of a first end of the sheet. A registration marker is deposited on the sheet proximate to a second end of the sheet in the first pass. The registration marker can include a marking material that is in the non-visible light range. A second side of the sheet is registered in a second pass in response to detection of the registration marker deposited on the sheet.

Abstract: An image forming apparatus includes a transfer material transportation device to transport a transfer material; a transfer device to transfer a toner image to the transfer material transported by the transfer material transportation device; a fusing device, disposed after the transfer device, to fuse a toner image on the transfer material transported by the transfer material transportation device; a registration device, disposed before the transfer device, to feed the transfer material, supplied from a sheet feeder, to the transfer device; and a biasing device, disposed for the registration device, to regulate movement of the registration device to decrease a speed difference between a transfer material transport speed generated by the transfer device and a transfer material transport speed generated by the registration device.

Abstract: An image forming apparatus includes a belt-shaped image carrier that carries an image, an image transfer unit that transfers the image onto a recording medium, and a conveying unit that conveys the recording medium to the image transfer unit. The image carrier has a sloping surface that slopes down from upstream of the image transfer unit in a conveying direction. The conveying unit includes a linear conveying path that is arranged upstream of the image transfer unit in the conveying direction, below the sloping surface and above a horizontal line passing through the image transfer unit.

Abstract: When an image is formed on a second side of a sheet, the image forming position is adjusted on the basis of a value calculated using the amount ?n of lateral registration deviation detected before forming an image on the first side and the amount ?n-1, of lateral registration deviation of the previous sheet on which image formation is performed. Thus, it is possible to adjust the positions of irradiation of laser light to the photosensitive drums and to start forming the second-side images as soon as the first-side images have been primary-transferred onto the intermediate transfer belt.

Abstract: According to aspects illustrated herein, there is provided a method and system for measuring and controlling an angular orientation of a printed sheet along a feed path of a print making device, the printed sheet being a sheet of paper with a paper edge moving along the feed path and an image printed thereon. The method includes the following steps. First, moving the printed sheet past at least one pair of optical sensors to determine a first skew of the paper edge with respect to a first fixed reference and a second skew of the image with respect to a second fixed reference. Then, combining the first skew and the second skew to determine the total skew between the paper edge and the image. Finally, correcting the total skew for subsequent sheets using the first skew and the second skew information. Similar steps can be taken to determine the lateral positioning errors which can then be corrected.

Abstract: A method and system for insuring printing accuracy in simplex imaging or duplex imaging, including a media sheet in a media path adapted to move the media sheet through the system. The media path includes sensors and a datum. The sensors include a leading edge sensor and a trailing edge sensor adapted to record the time of arrival of the edge. The edge arrival time difference is determined between the arrival time of the edge using output from the trailing edge sensor and the arrival time of the edge using output from the leading edge sensor. A correction factor is based upon the time difference. The time of arrival of the media sheet at the datum is determined using the correction factor to align items printed on both side of the media sheet.

Abstract: A printing medium alignment device and an image forming apparatus having the same, the image forming apparatus includes a printing medium supply unit to supply a printing medium, a printing unit to print an image on the printing medium supplied from the printing medium supply unit, and a printing medium alignment device to align the printing medium fed toward the printing unit. The printing medium alignment device includes: a register roller; an idle roller to form a nip with the register roller, to feed the printing medium to the printing unit; a register to move to a first position to block the printing medium from entering the nip, to align the printing medium, and to move to a second position to allow the printing medium to enter the nip; and a shutter roller mounted in the register shutter. When the register shutter is in the second position, the shutter roller rolls while in contact with the printing medium, to decrease a friction between the printing medium and the register shutter.

Abstract: Disclosed is a printer including a transverse tension sensor for detecting that a sheet being discharged has deviated in a paper width direction orthogonal to a discharging direction. The conveyance of the sheet is stopped based on a detection signal of the transverse tension sensor.

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: An image forming apparatus including an image forming apparatus and an image checking apparatus. The image forming apparatus includes a transport control unit which transports a recording medium at a transport speed, and forms an image on the recording medium. The image checking apparatus includes a transport-speed acquisition unit, a detector, a reading unit, and an operation-state notification unit. The transport-speed acquisition unit acquires transport-speed information from the image forming apparatus. The detector detects a mark shown on the recording medium. The reading unit reads a checking-target image formed by the image forming apparatus at a position distant from the mark, on the basis of the transport-speed information and information concerning a positional relationship between the mark and the checking-target image. The operation-state notification unit notifies the image forming apparatus of an operation state of the image checking apparatus.

Abstract: An image forming device makes a sheet pass between first rotating member and separator in a pressed position, causes second rotating member pair to transport a sheet, transports the sheet from second rotating member pair with the sheet held between third rotating member and image carrier in a transfer position, transfers an image formed on image carrier onto the sheet, and suspends rotation of first rotating member when a portion of the sheet, which is distance L away from the sheet's rear end, passes the pressed position. Provided that length 1?(M+L) and length 2<(M+L) where M is a distance from the pressed position to the transfer position, when the sheet has length 2 in a transport direction, the device delays image formation start and/or advances sheet transport start, by a predetermined time period as compared to when the sheet has length 1 in the transport direction.

Abstract: Disclosed herein is an image forming apparatus and a control method thereof. According to the control method of the image forming apparatus, entry and exit of a recording medium can be sensed without a register sensor by sensing current change of a press roller used to apply a constant pressure to the recording medium and a transfer belt so as to allow the recording medium and transfer belt to come into close contact with each other. In the case of a model provided with a register sensor, the presence of malfunction of the register sensor can be recognized.

Abstract: A load torque variation upon entry or exit of a sheet into a nipping portion is reduced while a nipping force necessary for image formation is provided. An image transfer apparatus, an image fixing apparatus, or a registration apparatus comprises an opposite roller, a transfer roller, and a compression spring for pressing the opposite roller onto the transfer roller. A sheet of transfer material is transported into a nipping portion between the opposite roller and the transfer roller, where an image on the opposite roller is transferred to the transfer material. The apparatus includes a retaining unit configured to retain a certain distance between the first rotating body and the second rotating body as long as the thickness of the transfer material that passes through the nipping portion remains the same.

Abstract: A moving unit causes a relative movement of a web and a mark detecting unit for detecting a ground color of the web and a mark color in a predetermined direction. A measuring unit measures a measurement value corresponding to a moving amount of the mark detecting unit with respect to the web in a time from when a detected color is switched from the ground color to the mark color till when a detected color is back to the ground color. A setting unit sets a threshold used for determining whether the color detected is the ground color or the mark color on the basis of the mark color detected by the mark detecting unit at the time when the mark detecting unit is moved in a reverse direction for a distance of half the measurement value since the color detected is back to the ground color.

Abstract: An image forming apparatus includes: an image forming section attached on an apparatus main body, having a forming and writing section that forms and writes an electrostatic latent image on an image carrier based on image information, and a transfer section which transfers a developed image after the electrostatic latent image has been developed, onto a sheet; a sheet conveyance section detachably attached on the apparatus main body, which conveys the sheet to the image forming section; a sheet detection section attached on the apparatus main body, which detects a sheet position conveyed to the image forming section by the sheet conveyance section; and a position correction section which corrects an image writing position for an image in the image forming section based on information of the detected sheet position.

Abstract: A length L of the test pattern string is determined so as to satisfy a condition L?{P?(Q1+Q2)}×V, where a time Q is a total time of a time Q1 for which the test pattern string is transferred from an exposure position of the test pattern string to a sensor and a time Q2 from when the test pattern is detected by the sensor until a color misregistration correction value calculated on the basis of a result of detecting is reflected in image formation; a time P is a time from a timing of starting to write the test pattern string to a timing of starting to write an image in which the correction value should be reflected; and a driving speed of a second image carrier is V.

Abstract: An image forming apparatus includes a belt-shaped image carrier that carries an image, an image transfer unit that transfers the image onto a recording medium, and a conveying unit that conveys the recording medium to the image transfer unit. The image carrier has a sloping surface that slopes down from an upstream of the image transfer unit in a conveying direction. The conveying unit includes a linear conveying path that is arranged an upstream of the image transfer unit in the conveying direction, below the sloping surface and above a horizontal line passing through the image transfer unit.

Abstract: A device for measuring a length of a recoding material, includes: a rotating body that rotates in contact with a recording material which is transported; a length measuring unit that measures a length of the recording material based on a rotation of the rotating unit; a detecting unit that detects at least one of a rotation and an oblique advance of the recording material; and a correcting unit that corrects a value measured by the length measuring unit based on an output of the detecting unit.

Abstract: An image forming apparatus that can detect a leading edge of a tabbed sheet after skew correction with high accuracy and without increasing a size of the apparatus. A transfer unit transfers a toner image to the sheet, the skew of which having been corrected based on a detection result of a first skew detection unit, while the toner image is controlled to be synchronized with the sheet based on the detection result of the first skew detection unit and a detection result of a second skew detection unit.

Abstract: In a method or system for controlling a printer or copier, a separation of a position mark printed on a web-shaped carrier material in a longitudinal direction of the carrier material relative to a transverse fold present in the carrier material is preset as a parameter. Arrival of the position mark is monitored with a sensor arrangement arranged before a transfer printing area while the carrier material is moved past the sensor arrangement. A real position of the transverse fold is determined for a position of arrival of the position mark at the sensor arrangement. The transverse fold is conveyed to a desired position by consideration of the real position of the transverse fold.

Abstract: In a transfer device, a first side of a flexible guide plate faces to a recording medium being conveyed along a medium conveyance path to guide the recording medium toward an image carrying member. A support frame supports an upstream end portion of the guide plate, and includes an opposite portion disposed from and opposite to a second side (reverse to the first side) of the guide plate and a rib configured to protrude from the opposite portion toward the medium conveyance path. The rib has a first edge which is positioned at an upstream side and beyond which the guide plate protrudes downstream. The rib has an inclined surface extending from the first edge in a direction obliquely downstream toward the image carrying member. The guide plate includes an indentation to allow the guide plate to be deflected without being blocked by the rib.

Abstract: Provided is a printing device including: a transport unit configured to transport a sheet-shape printing medium; a printing unit configured to print an image on the printing medium transported by the transport unit; a shape detection unit configured to detect the shape of edges of the printing medium; a position detection unit configured to detect the positions of the edges when an image is printed on the printing medium by the printing unit; and a first determination unit configured to determine the attitude of the printing medium based on the shape of the edges detected by the shape detection unit and the positions of the edges detected by the position detection unit, wherein the printing unit controls a printing position based on the attitude of the printing medium determined by the first determination unit and performs printing on the printing medium.

Abstract: In an apparatus which controls the bias of an intermediate transfer belt, the position shift of the width direction between a toner image and a recording material is reduced. Based on the results of estimating the variation moving in the width direction of the intermediate transfer belt, the position in the width direction of the recording material conveyed to a transfer position is changed to match the positions in the width direction of the toner image and the recording material.

Abstract: An image forming apparatus includes a moving roller capable of axial movement; a medium end position detecting section for detection in the main scanning direction; and a control section for calculating the amount of misalignment of the medium from the detected end position; wherein the control section obtains the correction amount of the image forming position of the medium according to the amount of misalignment of the medium having been calculated, or the amount of misalignment of the medium and information of moving position of the roller, and provides control such that the medium or another medium coming later than the medium by a predetermined number of pages is moved by the moving roller by the difference between the correction amount of the image forming position and the amount of misalignment of the target medium, and the image forming position is corrected according to the correction amount.

Abstract: An image forming apparatus includes an image forming unit, a sheet conveying unit, a TOD (Top of Data) control module for instructing the image forming unit to start generation of a toner image, a timing roller driving module for instructing the sheet conveying unit to start driving of the timing roller, an image synchronization module designed depending on the sheet conveying unit and the image forming unit, and a sheet information module for generating an image synchronization identifier for designating a pattern of image synchronization control related to printing of the toner image on the sheet, depending on a type of the sheet designated. The image synchronization module is activated when the formation of the toner image on the sheet has become possible, and activate each of the TOD control module and the timing roller driving module, with a relative time lag based on the image synchronization identifier.

Abstract: An image forming device includes a frame having an opening, a cover for the opening, a drum unit, a belt unit and a pair of registration rollers. The drum unit has a plurality of photosensitive drums defining an axis and being juxtaposed in line in a direction orthogonal to the axis. The belt unit has a plurality of rollers and an endless belt mounted over the plurality of rollers. The drum unit is movable in a first direction and accessible through the opening. The pair of registration rollers nips the recording sheets to correct skew in the recording sheets and to convey each recording sheet toward the belt unit. The pair of registration rollers is disposed at a side opposite to the drum unit. The pair of registration rollers defining a nip point located at a position aligned with the belt unit.

Abstract: A sheet conveying apparatus including: a sheet conveying path through which a sheet is conveyed; a sensor unit configured to output a signal according to a characteristic of the sheet which is conveyed through the sheet conveying path; a pressure unit configured to press the sheet against the sensor unit; and a moving member protruding into the sheet conveying path, the moving member being moved by being pushed by the sheet passing through the sheet conveying path, wherein the pressure unit is interlocked with the moving member so that the sheet is pressed by the pressure unit against the sensor unit when the moving member is not pushed by the sheet, and a pressure force on the sheet applied by the pressure unit is released or reduced when the moving member is pushed by the sheet.

Abstract: In a sheet conveying apparatus a first shape information that expresses at least a part of the outer shape of a sheet. An obtaining unit obtains second shape information that expresses at least the part of the outer shape of the sheet. A correction amount computing unit computes a correction amount of the sheet for correcting an image to be formed on the sheet and/or correcting the position and/or orientation of the sheet based on the first shape information and the second shape information. A correction amount computing unit computes a correction amount for correcting the position and/or orientation of the sheet relative to the conveying direction from the computed skew amount. A position and/or orientation correction unit corrects an image to be formed on the sheet and/or the position and/or orientation of the sheet, according to the computed correction amount.

Abstract: An image forming apparatus which is capable of correctly and accurately detecting a sheet leading edge position and carrying out image formation in appropriate image write timing, includes a detection device disposed at a reference position upstream from the transfer position and detects the recording medium being conveyed. A determining device determines image write timing for forming the electrostatic latent image on the photosensitive drum based on a difference in position between a leading edge position of the recording medium detected by said detection device and the reference position. The detection device respectively include a plurality of light detecting pixels disposed in a recording medium conveying direction, and the leading edge position of the recording medium detected by the respective light detecting pixels.

Abstract: An image forming apparatus includes a direct transfer control unit that controls a direct transfer unit and a first image forming unit so as to directly transfer an image onto a transfer sheet, an indirect transfer control unit that controls an intermediate transfer unit and a second image forming unit so as to transfer images onto the intermediate transfer unit, a secondary transfer control unit that controls contact/separation between the direct transfer unit and the intermediate transfer unit, a first alignment control unit that corrects an amount of misalignment among the images formed on the intermediate transfer unit, thereby performing a first alignment control process, and a second alignment control unit that corrects an amount of misalignment of an image directly transferred onto the transfer sheet with respect to the image on which the first alignment control process has been performed, thereby performing a second alignment control process.

Abstract: The image forming apparatus includes: an image holder that is movably provided; a first image forming unit that forms a first image on the image holder; a second image forming unit that forms a second image on the image holder including the first image formed thereon; a transfer portion that transfers, onto a recording medium, the first image and the second image formed on the image holder; a supply unit that transports the recording medium and that supplies the recording medium to the transfer portion; an acquisition unit that acquires information on a position of displacement on the recording medium in a transport direction of the recording medium, the displacement occurring between the first image and the second image transferred onto the recording medium; and an adjustment unit that changes a supply speed of the recording medium at the supply unit on the basis of the information on the position.

Abstract: The invention relates to a method and a device for controlling the circumferential register in a digital multi-color printing machine for printing sheets during a printing process, whereby, for each sheet, at least one register mark per color printing unit of the multi-color printing machine is produced, assigned to said sheet and defined with respect to its position, and whereby, based on the determination of the position of the register marks of a sheet, the circumferential register of at least one sheet, which follows the sheet associated with said determined register marks downstream of the printing process, is controlled. In duplex printing a sheet by recto and verso printing with the invention, register marks are applied for each side and, in order to control recto and verso printing of at least one subsequent sheet, said register marks are analyzed.

Abstract: A method and system modify a rasterized digital image to reduce registration artifacts, the image having a black plane and a color plane by determining if a pixel is part of a connected black region and if the pixel is part of a connected color region. It is determined if the pixel is part of a connected black region and a connected color region that are contiguous. A dilation operation is performed on the color plane value of the pixel if the pixel is part of a connected black region and a connected color region that are contiguous.

Abstract: An image forming apparatus includes a conveyance part; a detecting part; a control part which prints image data on the printing medium based on a detecting signal from the detecting part; a masking part configured to perform a masking process on the detecting signal generated by the detecting part between when the printing medium starts being conveyed from the printing medium receiving part and when the printing medium passes through a designated section; a conveyance distance measuring part configured to measure a conveyance distance of the head end of the printing medium conveyed from a receiving position of the printing medium receiving part; a determining part configured to determine whether the printing medium stops in an uncertain position not detected by the detecting part when the conveyance part stops while the printing medium is being conveyed by the conveyance part; and a masking process section setting part configured to set.

Abstract: In a color misalignment detection method, an alignment pattern is obtained by designating a plurality of lines having line width and line intervals formed by superposing a line image of a black color as a reference color and a line image of a color other than the reference color, for example, a cyan line image, as one patch, and continuously forming these patches by shifting the relative position between the line images of the two colors by an optional quantity. An alignment pattern detection sensor has a light emitting diode and a photodiode. These elements are arranged along the scanning direction of the alignment pattern such that the photodiode can only receive diffused reflected light of reflected light from the alignment pattern. A spot shape of the light emitting diode and a spot shape of the photodiode are both formed in a square shape.

Abstract: A digital printing system employing tandem marking engines for duplex printing utilizing a variable dwell time in the output sheet inverter of the first marking engine to provide correct positioning of the leading edge of the inverted sheet for arrival at the entrance of the second marking to avoid the seam in the photoreceptor.

Abstract: An image forming apparatus which secondarily transfers a toner image primarily transferred onto an intermediate transfer belt, including: a registration roller pair; a registration motor; a secondary transfer unit located downstream of the registration roller pair and secondarily transferring the toner image onto a sheet; a detection sensor detecting the presence or absence of the sheet transported on a sheet transport path downstream of the secondary transfer unit; a suction transport belt transporting the sheet; and a control unit controlling to stop the registration motor in a case that the control unit determines absence of the sheet on the sheet transport path based on a signal from the detection sensor, when an interval of time, which is expected to be taken from when starting to transport the sheet by the registration roller pair to when a leading edge of the sheet reaches the suction transport belt, has elapsed.

Abstract: The invention relates to a method of ensuring a correct lateral registration setting, in a digital multi-color electrographic sheet-printing machine, which the sheets adhere to a support, preferably a transport belt, are transported past printing units.