Abstract: An inkjet printer and a method for controlling an inkjet printer are disclosed. The inkjet printer is provided with an endless transport belt for transporting a medium to be printed; at least one roller for driving the transport belt and at least one additional roller for driving and/or suspending the transport belt; a detection system configured to detect a deformation of the transport belt including at least an in-plane bending deformation of at least a stretch of the transport belt and to generate at least one deformation signal indicating the detected deformation; an actuator assembly configured to change a position and/or orientation of at least one of the rollers of the inkjet printer; and a controller configured to control the actuator assembly based on the at least one deformation signal.

Abstract: An image forming apparatus includes a controller to move a sheet, in an image formation process on a first surface, to a standard position in a width direction and move the sheet, in an image formation process on a second surface, in the width direction based on a detected position in a case where a difference between the standard position and a first position in the width direction is equal to or smaller than a predetermined value. The controller moves the sheet, in the image formation process on the first surface, by the predetermined value in the width direction and moves the sheet, in the image formation process on the second surface, in the width direction based on detected positions in a case where the difference between the standard position and the first position in the width direction is larger than the predetermined value.

Abstract: An image reading apparatus includes a feeding roller that includes a first roller and a second roller provided at an interval in a width direction intersecting a medium feeding direction, and feeds a sheet from a placing section; and a skew detection section that detects skew of the sheet fed from the feeding roller. Skew is corrected by giving a difference between a rotation speed of the first roller and a rotation speed of the second roller with respect to at least one of the relevant sheet detected by the skew detection section and subsequent sheets fed following the relevant sheet based on a skew amount in the sheet.

Abstract: A scanner having a medium transport device has: a medium placement section disposed so as to be exposed to the outside of a cabinet, the medium placement section having a placement surface on which paper to be transported is placed; a supply roller that feeds the paper in a transport direction by being rotated while in contact with a surface of the paper, the surface facing the placement surface; and a two-dimensional sensor disposed in the medium placement section. The two-dimensional sensor has a light emitting section that can emit light toward the paper placed in the medium placement section, and also has a light receiving section that can receive reflected light from the paper. The light receiving axis of the light receiving section intersects part of the cabinet.

Abstract: An image forming apparatus includes a transfer belt, a plurality of endless rotational bodies, an image forming device, a pattern sensor, and processing circuitry. The image forming device forms correction patterns including a first pattern as a straight line pattern orthogonal to a conveyance direction of the correction patterns and a second pattern as one of a straight line pattern orthogonal to and an oblique line pattern inclined with respect to the conveyance direction. The processing circuitry causes the image forming device to form the correction patterns using a correction value such that the second pattern included in one correction pattern on the transfer belt is same in color and shape as the second pattern included in at least one correction pattern of a preceding correction pattern and a following correction pattern in the conveyance direction with respect to the one correction pattern.

Abstract: An image forming apparatus that highly precisely suppresses misregistration of an image relative to a sheet due to sub-scanning skew and a control method are provided. The image forming apparatus includes: displacement rollers including at least a pair of rollers conveying a sheet that is being conveyed, toward a transfer section; a detection section that detects a position of a side end part of the sheet; and a hardware processor that performs processing for displacing the displacement rollers based on displacement control information and correcting the displacement control information for next and subsequent sheets based on a detection result of detection by the detection section after the displacement of the displacement rollers.

Abstract: This image forming device is provided with: an image reading unit; a control unit which generates distribution data indicating the distribution of an angle of inclination of documents (D) read during a pre-determined time period, performs a test to determine whether there is a significant difference between the distribution data and standard distribution data, and on the basis of the test result determines whether maintenance of the image forming device is required; and a communication unit which, if it has been determined that maintenance is required, transmits a maintenance request notification to a service system.

Abstract: A belt slippage correcting device includes: a belt moving part that moves a belt in a width direction of the belt; a slippage detector that detects a slippage of the belt in the width direction; a hardware processor that controls a movement of the belt caused by the belt moving part based on the slippage of the belt detected by the slippage detector; and an acquisitor that acquires paper sheet conveying property, wherein the hardware processor controls an amount of movement of the belt caused by the belt moving part based on the paper sheet conveying property acquired by the acquisitor.

Abstract: A scanner apparatus includes a document feeding path in which a reading device configured to read an image from a document is provided, a first registration roller configured to feed the document along the document feeding path, and located at an upstream side of the reading device based on a feeding direction of the document, a second registration roller aligned with the first registration roller in a width direction of the document, and located spaced apart from the first registration roller in the width direction, a registration motor configured to drive the first registration roller, and a main motor configured to drive the second registration roller.

Abstract: An image forming apparatus comprising: a controller controlling an image forming unit to form a test image, controlling a measurement unit to measure the test image on an image bearing member, and controlling a transfer unit to transfer the test image formed on the image bearing member to the sheet; a reception unit receiving a user instruction; and a second generation unit generating the conversion condition based on the user instruction and the measurement result of the test image, wherein the test image includes a first test image, a second test image, and an image indicating a position where the sheet is to be bent, and in a case where the sheet is bent along the position, a position of the first test image and a position of the second test image do not overlap with each other.

Abstract: Systems and methods for printhead position control. The system comprises a controller that identifies a target distance for moving a printhead in a lateral direction to compensate for lateral shifts in a web of print media as the web travels in a continuous-forms printer in a conveyance direction. The controller also identifies a maximum distance for moving the printhead in the lateral direction based on an allowable print error in a color plane of the printer and one or more previous positions of the printhead. The control further moves the printhead for a distance that is a lesser of the maximum distance and the target distance.

Abstract: An image forming apparatus includes a fixing unit, detection units, and a control unit. The control unit switches a sheet speed at the fixing unit to either a first or second sheet speed that is faster than the first sheet speed based on a first detection unit signal where the control unit detects that both a loop amount of a sheet loop at second and third detection unit positions are greater than or less than a predetermined amount. The control unit sets the fixing unit sheet speed as a predetermined sheet speed between the first and second sheet speed where the control unit detects that one of two loop amounts detected the second and third detection units is greater than the predetermined amount when the other one of the two loop amounts is less than the predetermined amount.

Abstract: An image forming apparatus includes: a transfer part configured to transfer an unfixed toner image transferred from a photosensitive member onto a recording medium; a pair of pre-transfer rollers configured to convey a recording medium toward the transfer part; a fixing part configured to make the recording medium onto which the toner image is transferred pass between a pair of fixing rollers to fix the toner image onto the recording medium; a first detection sensor configured to detect a position of the recording medium between the transfer part and the pair of pre-transfer rollers; a second detection sensor configured to detect a position of the recording medium downstream of the pair of pre-transfer rollers; and a controller configured to calculate a deviation amount of the recording medium, rock the pair of pre-transfer rollers and adjust a position to which an image is written to form a toner image.

Abstract: A transport mechanism includes a transport path along which a recording medium is transported, a contact member with which a leading end of the recording medium, which is to be transported along the transport path, is brought into contact, the contact member being capable of moving to a contact position at which the leading end of the recording medium is brought into contact with the contact member or to a retracting position at which the contact member retracts from the transport path, a transport member that transports the recording medium, which has been brought into contact with the contact member, to downstream in a transport direction of the recording medium while rotating in a normal direction, and a rotational force transmission member that transmits a rotational force of the transport member to the contact member and causes the contact member to move to the contact position or the retracting position.

Abstract: A sheet conveying unit includes a shutter portion including an abutting portion correcting a skew of a sheet by abutting against a front end of the sheet at a standby position upstream in a sheet conveying direction of a nip of the conveying roller pair, and a bias portion biasing the shutter portion such that the abutting portion is positioned at the standby position. The bias portion is configured such that a rate of increase of a bias force applied from the bias portion to the shutter portion during when the abutting portion is turned from the standby position to a nip position where the sheet is nipped by the conveying roller pair is smaller than a rate of increase of the bias force during when the abutting portion turns by being pushed by the sheet nipped by the conveying roller pair from the nip position.

Abstract: A supporting portion is provided to project from an upper surface of a side regulating member which is provided in a sheet feeding cassette which is detachably attached to a color laser beam printer body, and which regulates a position of a sheet in a width direction orthogonal to a sheet feeding direction, and this supporting portion regulates downward deformation of a conveyance guiding member which is positioned above the sheet feeding cassette and which forms a sheet conveying path R which guides the sheet.

Abstract: An image forming apparatus has an image forming section having a photoreceptor on which a toner image is formed, an endless belt that revolves with its outer surface facing the photoreceptor, a steering roller adapted to provide a tension to the belt and adjust the position of the belt in the width direction, a transfer roller that presses the belt toward the photoreceptor so as to form a transfer nip where the toner image is transferred, a transfer pressure adjusting mechanism adapted to adjust pressing force when the transfer roller presses the belt toward the photoreceptor, and a controller adapted to control the pressing force adjusted by the transfer pressure adjusting mechanism, according to the adjustment state of the steering roller.

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: The present invention is directed to downsize the main body and achieve a good image quality at a low cost. A rotation shaft of a first discharge roller is tilted with respect to that of a second discharge roller. The center of oscillation C of a first discharge roller holding member is provided more upstream in the direction in which a sheet is discharged than a straight line made by the rotation center of the first discharge roller and the rotation center of the second discharge roller.

Abstract: A conveying device has a conveying belt configured to convey a sheet. A printing device is configured to print an image on the sheet that is conveyed by the conveying device in a conveying direction. A plurality of sensors is arranged to be spaced away from each other in a main scanning direction that is perpendicular to the conveying direction. The plurality of sensors is configured to emit light to different detection regions on an outer peripheral surface of the conveying belt and to receive light reflected by the conveying belt. A controller is configured to execute a skew-detection-mark printing process of controlling the printing device to print a skew detection mark at positions passing the respective detection regions so that the skew detection mark extends over an end of the sheet in the conveying direction and the outer peripheral surface of the conveying belt.

Abstract: A sheet conveyance device for conveying a recording medium includes a fixed roller, a movable roller, an urging member, and a shock absorber, and an image forming apparatus including the sheet conveyance device. The position of the fixed roller is fixed. The movable roller is disposed opposite the fixed roller to contact the fixed roller, thereby defining a nip. The urging member urges the movable member to contact the fixed roller in the absence of the recording medium in the nip and allows the movable member to separate from the fixed roller by an amount corresponding to a thickness of a recording medium when the recording medium enters the nip. The shock absorber absorbs displacement energy generated when the urging member urges the movable roller to contact the fixed roller again after the recording medium passes through the nip.

Abstract: There is provided an image forming apparatus including: a sheet feeding unit; photoconductors; a transfer belt unit; a first and second frame units; and a bridging member bridging the first and second frame units. Each of the photoconductors is held by the first and second frame units. The transfer belt unit is biased to the one end side in the width direction to abut on the first frame unit and the bridging member, to thereby be positioned with respect to the first frame unit and the bridging member. The sheet feeding unit abuts on at least two places, of the bridging member, in the width direction from a perpendicular direction, to thereby be positioned with respect to the bridging member.

Abstract: A sheet feeding mechanism incorporatable in an image forming apparatus includes a cover unit rotatably attached to one side of a main body of an image forming apparatus to cover a part of a sheet conveyance path, a first feeding member located in a main body of the apparatus, a second feeding member located in the cover unit in a displaceable manner and facing the first feeding member when the cover unit is closed and sandwiching and conveying a recording medium along the sheet conveyance path with the first feeding member, and a guide member disposed in the main body to guide the second feeding member. The guide member guides the second feeding member to move in a first direction that approaches the first feeding member when closing the cover unit and in a second direction that separates from the first feeding member when opening the cover unit.

Abstract: An image-forming device includes a casing, a conveying path, a pair of registration rollers, and a process cartridge. The conveying path is disposed in the casing to convey a recording sheet. The pair of registration rollers is disposed on the conveying path to regulate a leading edge of the recording sheet conveyed along the conveying path. The process cartridge is detachably mounted on the casing, and includes a developer accommodating unit, a photosensitive member, and an upstream guide part. The photosensitive member is disposed on the conveying path. The upstream guide part is disposed upstream of the pair of registration rollers on the conveying path to guide the recording sheet toward the pair of registration rollers in cooperation with the conveying path. The upstream guide part is formed with a concaved part that is concaved in a direction away from the conveying path.

Abstract: An image forming apparatus includes a belt member; a toner image forming portion for forming a toner image on the belt member; a transfer portion where the toner image formed on the belt member is to be transferred onto a recording material; a recording material supplying portion for supplying the recording material to the transfer portion; a steering portion for adjusting a widthwise position of the belt member by being tilted; and an adjusting portion for adjusting a conveyance direction of the recording material supplied by the recording material supplying portion so that a conveyance direction of the belt member when the steering portion is tilted is the same as the conveyance direction of the recording material supplied by the recording material supplying portion.

Abstract: An image heating device includes an endless belt including a base layer and an elastic layer formed around the base layer, a contact member contacting an inner surface of the endless belt, a pressure rotating member forming a nip portion configured to convey a recording material while nipping the recording material along with the contact member via the endless belt, wherein an image formed on the recording material is heated at the nip portion using heat from the endless belt, and wherein one end of the endless belt is coated with the elastic layer and the other end of the endless belt is not coated with the elastic layer, and a belt lateral shifting direction regulating mechanism configured to regulate a direction in which the endless belt shifts when the endless belt is rotated, toward the end coated with the elastic layer.

Abstract: An image forming apparatus has a pair of registration rollers which are moved in the width direction so that a sheet side end position is within a predetermined range in the width direction based on sheet side end position information from a lateral registration detection sensor. In the case that an image-formed sheet is conveyed to a sheet processing portion without being reversed, the pair of registration rollers are moved so that the sheet side end position is within the first range, and in the case that an image-formed sheet is conveyed to the sheet processing portion, the pair of registration rollers are moved so that the sheet side end position is within the second range being different from the first range before reversing and within the first range after reversing.

Abstract: A conveyor has a first conveying unit including a pair of first nip roll sets configured to nip and convey the sheet, and a second conveying unit including a second nip roll set configured to nip and convey the sheet from the first conveying unit. The second nip roll set nips the sheet at an inner location than the first nip roll set, and the first nip roll set nips the sheet more strongly than the second nip roll set.

Abstract: A sheet transporting device includes a regulating member that is arranged so that an edge of a sheet is abutted against the regulating member while moving downstream in a transporting direction of the sheet, and a first transport member that transports the sheet toward the regulating member while moving downstream in the transporting direction, and that pushes the sheet against the regulating member while slipping on a surface of the sheet in a state where the sheet is abutted against the regulating member, wherein the regulating member and the first transport member moving together downstream in the transporting direction.

Abstract: In one embodiment, printing, on a first side of a media, of a first plurality of plots and a plurality of associated fiducials is caused. For each of a second plurality of plots, using data from a sensor, a distance to one of the plurality of associated fiducials is measured to discern a reference for printing that plot on a second side of the media. Printing of the second plurality of plots on the second side is caused so that each of the second plurality of plots is substantially in registration with one of the first plurality of plots.

Abstract: A printing method that alternately repeats a transport operation that transports a continuous medium in a transport direction and an image forming operation that moves a head to form an image to thereby print out a first image and a second image, which has a smaller length in the transport direction than the first image, on the continuous medium.

Abstract: Overlap positioning systems are provided for use with a receiver transport system that moves receiver from a pre-printing path, past a print engine, to a post-printing path. In one aspect, the overlap positioning system has a receiver transport system that moves receiver from a post-printing path to a reentry point in the pre-printing path, a diverter selectively diverts the first receiver from the post printing path into a recirculation system having a plurality of surfaces to guide the first receiver from the post printing path to a reentry in the pre-printing path; and a receiver movement system moves the first receiver through the recirculation system; a controller and sensor system cooperate to cause one of the first receiver or a second receiver to be first through the reentry point and the other is advanced through the reentry point at a point where an overlap of a determined amount is provided.

Abstract: In a sheet member position correcting device and an image forming apparatus according to the present invention, a controller moves a driving roller toward one end side of the width direction by using a moving unit until a driven roller the position of which is deviated in the width direction with respect to the driving roller abuts on a stopper portion, and, subsequently, the controller further moves the driving roller to a predetermined position toward one end side of the width direction by using the moving unit in a state where the driven roller abuts on the stopper portion to correct the position of the driven roller in the width direction with respect to the driving roller.

Abstract: A sheet conveying apparatus includes: a shutter member against which a leading edge of a sheet being conveyed abuts, for a skew feed correction, wherein the shutter member is pressed and moved by the sheet; and an actuation member which moves the shutter member that has been pressed and moved by the sheet being conveyed to a retracted position at which the shutter member is retracted from a sheet conveying path and holds the shutter member at the retracted position until the leading edge of the sheet being conveyed by the second conveying rotary member is nipped by the transfer nip portion.

Abstract: An image processing apparatus includes a reading part configured to optically read skew amount measurement patterns and opposite ends of a paper sheet; an image skew amount detecting part configured to detect skew amounts on a color basis based on the skew amount measurement patterns; a paper sheet skew amount detecting part configured to detect a skew amount of the paper sheet based on a displacement between the opposite ends of the paper sheet; a skew correction amount calculating part configured to calculate skew correction amounts of the respective colors based on the skew amounts; and a skew correcting part configured to shift the images to correct the skews by recording input image data in plural lines of a line memory, dividing the input image data into plural areas in a main scanning direction, and setting line delay amounts on an area basis based on the skew correction amounts.

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: A system and method is disclosed for print production sheet identification. The method discloses: receiving a set of calibration sheets; collecting an array of pixel samples from at least one of the calibration sheets according to a set of pixel sampling rules to generate at least one reference sample array; capturing an image of a set of physical sheets generated from the set of calibration sheets; collecting an array of pixel samples from at least one of the imaged physical sheets according to the set of pixel sampling rules to generate at least one post-processing sample array; and comparing the post-processing sample array to the reference sample array to determine if the two arrays have less than or equal to a predetermined number of differences. The system discloses: a sampling module, operated by a processor, a scanner, and a comparison module, operated by a processor.

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 conveying device has a conveying belt configured to convey a sheet. A printing device is configured to print an image on the sheet that is conveyed by the conveying device in a conveying direction. A plurality of sensors is arranged to be spaced away from each other in a main scanning direction that is perpendicular to the conveying direction. The plurality of sensors is configured to emit light to different detection regions on an outer peripheral surface of the conveying belt and to receive light reflected by the conveying belt. A controller is configured to execute a skew-detection-mark printing process of controlling the printing device to print a skew detection mark at positions passing the respective detection regions so that the skew detection mark extends over an end of the sheet in the conveying direction and the outer peripheral surface of the conveying belt.

Abstract: A sheet skew correcting device includes a first sheet conveyance unit which a conveyance force at a center side is less than a conveyance force at a first side, a second sheet conveyance unit which is adjacent to the first sheet conveyance unit across the center and a conveyance force at the center side is less than a conveyance force at a second side, a first drive unit to drive the first rotator, a second drive unit to drive the third rotator, a detection unit to detect an inclination of the sheet, and a control unit to control the first drive unit and the second drive unit based on a detection result of the detection unit.

Abstract: There is provided an image forming apparatus including: a sheet feeding unit; photoconductors; a transfer belt unit; a first and second frame units; and a bridging member bridging the first and second frame units. Each of the photoconductors is held by the first and second frame units. The transfer belt unit is biased to the one end side in the width direction to abut on the first frame unit and the bridging member, to thereby be positioned with respect to the first frame unit and the bridging member. The sheet feeding unit abuts on at least two places, of the bridging member, in the width direction from a perpendicular direction, to thereby be positioned with respect to the bridging member.

Abstract: A sheet conveyance device that is capable of correcting skew of a sheet like an index sheet without complicating a use setting and without increasing a cost significantly. A plurality of conveyance units are arranged in a direction intersecting a sheet conveyance direction to convey a sheet. At least three detection sensors are arranged in a direction intersecting the conveyance direction at an upstream side from the conveyance units to detect the sheet. A skew amount computation unit measures a time difference between detection timings of a front end of the sheet by two of the at least three detection sensors except the detection sensor that detects first, and computes a front-end skew amount according to the time difference. A speed change unit makes the conveyance speeds of the conveyance units be different according to the front-end skew amount so as to correct the skew of the sheet.

Abstract: An image forming apparatus includes plural image forming units of plural colors, each including a print head including plural LED chips aligned in a main scanning direction; a screen angle selecting unit that selects screen angles for the plural colors respectively based on the amounts of skew of the plural image forming units; an image processing unit that performs image processing on input data to be expressed by pixels of the plural colors such that the pixels of the colors have the corresponding screen angles selected by the screen angle selecting unit; a correction amount determining unit that determines a total amount of skew correction based on the amount of skew detected by the skew detection unit, and determines the amounts of skew correction in the sub-scanning direction for predetermined groups of the pixels, based on the total amount of skew correction, for each of the colors.

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 comprises an image-forming part; a paper feeding part; a resist part; a rotating body; a detector for detecting the arrival of paper at the resist part; a timer part for measuring a measurement time from when feeding of a second sheet of paper from the paper feeding part is begun to when the detector detects the arrival of the second sheet of paper, and a sheet interval time from when the detector detects the passage of a first sheet of paper immediately preceding the second sheet of paper to when the arrival of the second sheet of paper is detected; and an identifier part for referring to the measurement time, a reference measurement time, the sheet interval time and a reference sheet interval time, and deciding the paper feeding part advancing or delaying the paper feed start timing.

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: 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: 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.