Abstract: A printer-processor is provided with a paper feed path that is constituted of a plural number of pairs of conveyer rollers, and a feedback path that branches off the paper feed path to feed a sheet of recording paper back to an upstream position of the paper feed path that is placed before an image recording section. For both-side printing, the paper sheet is first conveyed in a forward direction through the image recording section, to record an image on one side. After being conveyed further in the forward direction along the paper feed path to go past a branching section to the feedback path, the paper sheet is conveyed backward into the feedback path. Thus, the conveying direction through the image recording section is unchanged regardless of which side of the paper sheet is served for the image recording.

Abstract: A printer controller comprising a rasterizing part for producing raster data as printing data, a skew correcting part for correcting the raster data for a skew error in accordance with a correction coefficient delivered form the color image forming device and indicating a skew error, a compression part for compressing the raster data corrected for the skew error so as to deliver the compressed raster data, and storing the compressed raster data in memory, an expansion part for expanding the compressed raster data so as to restore the raster data, and a magnification correcting part for correcting the raster data delivered from the expansion part, for a magnification error accordance with correction coefficient delivered from the color image forming device and indicating a magnification error. With this configuration, it is possible to eliminate the necessity of line memory.

Abstract: Color register and/or register errors are detected in a printing machine by using triangles serving as register marks. A first triangle is printed onto a sheet near the leading edge and a second triangle is printed onto a sheet near its trailing edge. The first triangle and the second triangle are detected by a sensor and a displacement of the sheet at right angles to the travel direction of the sheet and/or an angular displacement of the sheet is/are determined.

Abstract: The image forming apparatus includes an image forming unit installed in a main body of the image forming apparatus and a tray stack including stacked media supplying units for supplying the media piece from selected one of the stacked media supplying units to the image forming unit. The tray stack is detachable from and attachable to the main body. The tray stack includes a register installed only in uppermost one of the stacked media supplying units. The register functions to correct skew of the media piece with respect to a transport direction along which the media piece is transported and then feed the media piece to the image forming unit.

Abstract: Systems and methods of registering a sheet in an image reproduction, e.g., a xerographic, device use sheet parameters regardless of the tray or bin with which the sheets are associated, separate tallies of sheet registration correction factors for both sides of a sheet, and use registration errors detected on a first side of a sheet to generate correction factors concerning proper registration of the second side of that sheet. In embodiments, the systems and methods average registration errors for one particular side of a plurality of sheets to obtain a damped error signal that is taken into account for registration of subsequent sheets on each respective sheet side. In embodiments, the systems and methods determine variations between actual and target system performance to affect subsequent sheet flow and registration.

Abstract: A method to be used within a document image capture device, such as a document scanner (10) of detecting and measuring the document skew (25) while the document is still entering the imaging area and then effecting a rotation of the camera to accommodate the document skew so that the resulting image taken is not skewed. This can be accomplished by one of several methods, such as rotating the entire camera, rotating only the sensor element, or rotating another element in the optical path such as a prism. Use of the methods incorporated in this invention does not require the document motion to be stopped to measure and accommodate skew or to take the image.

Abstract: A printing machine (10) including a registration station (45) for applying a skew adjustment received from a human operator is disclosed. The registration station (45) includes independently controllable motors (52a, 52b) that drive corresponding urging rollers (56a, 56b) as controlled by control circuitry (24), for example in response to the position of a media sheet as sensed by sensors (58a, 58b; 60a, 60b) at the registration station (45). The machine operator can enter a skew adjustment value at a user interface (25a), or at a networked computer workstation with which the printing machine (10) communicates via a network interface (25b). The control circuitry (24) calculates differential control signals for controlling the motors (52a, 52b) to effect the skew correction. The differential control signals may be differential timing delays, such as prior to deactivation of the motors (52a, 52b), or may be a differential velocity signal for driving the motors (52a, 52b).

Abstract: An image forming apparatus forms a toner image on a moving member by transferring and superposing component color toner images formed on an image bearer. An image forming apparatus includes a driving device that rotates and transports a moving member, a moving value detecting device that detects one of a moving length and a moving speed of the moving member, and a deviation calculating device that calculates a deviation value of one of the moving length and the moving speed by subtracting the detected one of the moving length and the moving speed from a reference value. An adjustment value calculating device calculates an adjustment value in accordance with the calculated deviation value. A driving speed control device controls a driving speed of the driving device in accordance with the calculated adjustment value.

Abstract: A paper feeder including a fixed guide disposed at one side of a paper feeding tray. The fixed guide functions as a standard of position adjustment of documents, and faces in an orthogonal direction against a document transporting direction. The documents are fed from the document feeding tray by a pick-up roller, separated into one-by-one and fed to the downstream by a document separator comprised of a separate roller and a retard roller. These pick-up roller, separate roller, retard roller are disposed within the smallest width size of the documents stacked on the document feeding tray. The documents fed to the downstream are fed to a reading unit by the feed roller mounted in the movable guide side located opposite to the standard line. After the image data of the document is read by the reading unit, the document is discharged to the paper discharging tray by an extra roller.

Abstract: A method and device for moving media sheets along a media path. In one embodiment, the media path comprises a metering nip, at least one transfer nip downstream from the metering nip, and a feed nip upstream from the metering nip. The feed nip moves the media sheet initially at a faster speed than the metering nip. This speed variation causes a buckle to form in the media sheet that aligns the leading edge. The media sheet is then moved from the metering nip into the transfer nip. The metering nip may move the media sheet at a faster speed than the transfer nip again forming a buckle in the media sheet. As the media sheet is moved through the transfer nip, it is tacked to a transfer belt such that it moves consistently through the remaining downstream transfer nips.

Abstract: A transfer device for transferring an object to be transferred in a predetermined direction has a drive mechanism unit, a transfer direction displacement information acquiring unit, a skew direction displacement information acquiring unit, and a transfer processing unit. The drive mechanism unit also has roll parts which cause the object to be transferred to move in the direction with a rotational force. The transfer direction displacement information acquiring unit and the skew direction displacement information acquiring unit radiate a predetermined measuring wave toward the object, so that the units acquire the displacement information in each of the directions. Based on the displacement information, the transfer processing unit performs a predetermined processing.

Abstract: A method of registering a sheet in a duplex copier to alleviate the misalignment between the images copied on the front and back of the same sheet and to compensate for paper cut tolerances. The error angle of skew between a target angle, e.g. 90°, and the trailing edge of the sheet is measured and stored during a first pass. When the same sheet is fed through a second pass, the error angle is retrieved and the target angle is adjusted to compensate for the skew error of the first pass so that any misalignment between front and back images is substantially improved over systems that register images to the sheet without any knowledge of the location of the opposite side image.

Abstract: A printer including a main body and a sheet-supply cassette attachable to and detachable from the main body. The sheet-supply cassette includes a sheet guide movable to a position that depends on size of sheets in the cassette, cam abutment portion that moves integrally with the sheet guide, a cam that moves away from the cam abutment portion when the cassette is detached from the main body, and a detected portion that moves in a linked manner with the cam. The main body includes a cam mover that, when the sheet-supply cassette is attached to the main body, moves the cam until the cam surface of the cam abuts the cam abutment portion and a detection portion that detects the detected portion moved in a linked manner with the cam. The cam surface has a shape that varies movement amount of the cam into abutment with the abutment portion by the cam mover in accordance with the position of the sheet guide.

Abstract: In a laser printer capable of printing on both sides of a sheet, alignment or skew of the sheet is corrected with register rollers before printing is performed first on a side of the sheet. The sheet with an image having been formed by a process unit is fed to a re-circulation path for printing on the other side of the sheet. The sheet alignment or skew is corrected in the re-circulation path by a guide plate while the sheet is fed by re-circulation feed rollers. The sheet fed back to the register rollers is fed toward the process unit without being temporarily stopped at the register rollers before printing on the other side of the sheet.

Abstract: A paper transferring device for an image forming apparatus includes a plurality of guide members forming a paper transferring path connecting a paper feeding device and a photosensitive drum, a feeding roller disposed on a side of the paper transferring path adjacent to the photosensitive drum, the feeding roller transferring a paper incoming along the paper transferring path to the photosensitive drum, at least one transferring roller disposed on the paper transferring path between the feeding roller and the paper feeding device, the transferring roller transferring the paper picked-up from the paper feeding device to the feeding roller, and a paper leading edge aligning unit for aligning a leading edge of the paper so that the leading edge of the paper is parallel to a rotation axis of the feeding roller prior to entering the feeding roller to prevent the paper from being skewed.

Abstract: A method of controlling the velocity of a copy substrate in an electrophotographic reproduction machine which includes a substrate registration system for transporting and registering the substrate and a toner image traveling to a toner image transfer point at a transfer velocity. The method includes decelerating the substrate from a process velocity to a low velocity, where the transfer velocity is greater than the low velocity and less than the process velocity, registering the substrate via the substrate registration system, and accelerating the substrate to the transfer velocity for image transfer.

Abstract: Systems and methods of registering a sheet in an image reproduction, e.g. . , . a xerographic, device use sheet parameters regardless of the tray or bin with which the sheets are associated, separate tallies of sheet registration correction factors for both sides of a sheet, and use registration errors detected on a first side of a sheet to generate correction factors concerning proper registration of the second side of that sheet. In embodiments, the systems and methods average registration errors for one particular side of a plurality of sheets to obtain a damped error signal that is taken into account for registration of subsequent sheets on each respective sheet side. In embodiments, the systems and methods determine variations between actual and target system performance to affect subsequent sheet flow and registration.

Abstract: A sheet to sheet electronic skew correction system measures the input skew of each incoming sheet “on-the-fly” with sensors and then adjusts the image electronically to match the skew of the particular sheet. Thus, the image placed on the sheet from a photoreceptor is square with the dimensions of the sheet since the image is an exact match with the skew orientation of the sheet.

Abstract: An image forming apparatus in that a sheet having an image formed on a first side thereof by an image forming portion is again transported to the image forming portion so that an image may be formed on an opposite or second side of the sheet, the image forming apparatus including a sheet feeding portion, a re-transport path, a pair of registration rollers provided upstream of the image forming portion, and a loop forming space provided upstream of the pair of registration rollers so as to form the loop, wherein an entrance to the loop forming space for the sheet having passed along the re-transport path is formed downstream of an entrance to the loop forming space for the sheet fed from the sheet feeding portion.

Abstract: In an image forming apparatus and an image forming method, a paper position aberration detecting sensor including a light emitting element and a light receiving element is disposed in the paper conveying path of the image forming apparatus. The amount of paper position aberration in paper conveyance is detected by a counter, and on the basis of the result of the detection, a CPU controls the writing start position of a printed image.

Abstract: A registration system including both a primary tamping device and a secondary scuffing device. The scuffing device includes a scuffer arm, an extending/retracting device, a drive subsystem, and an engagement control device. In various exemplary embodiments, the secondary scuffing device is retracted. The scuffing device can thus be used, when required, to register a substrate in the process direction and then retracted enabling the side tampers to cross process register the substrates. In various exemplary embodiments, substrates of varying sizes and types can be registered into common sets using the systems and methods of this invention.

Abstract: A sheet conveying device has a sheet-position detection sensor which has CCDs or CISs and which is attached in an inclined manner such that a vertical distance from the sheet-position detection sensor to a sheet-conveying path or to a sheet conveyed along the sheet-conveying path differs between the proximal edge and the distal edge of the sheet-position detection sensor in a direction perpendicular to the sheet-conveying path.

Abstract: The image forming apparatus includes an image forming unit installed in a main body of the image forming apparatus and a tray stack including stacked media supplying units for supplying the media piece from selected one of the stacked media supplying units to the image forming unit. The tray stack is detachable from and attachable to the main body. The tray stack includes a register installed only in uppermost one of the stacked media supplying units. The register functions to correct skew of the media piece with respect to a transport direction along which the media piece is transported and then feed the media piece to the image forming unit.

Abstract: The skew of a sheet of print media is precisely controlled by intentionally inducing print media deformation, so that cooperative mechanical and gravitational forces may be used to align the leading edge of the sheet. The sheet is driven into a nip region of deskew rollers in a manner that causes the print media to deform, lifting a movable member in a direction substantially perpendicular to the feedpath into the nip region. The movable member applies a return force that is generally equal along a widthwise surface region of the print media. As a result, there is a reduced likelihood that the print media will be skewed relative to the nip region. In some applications, the return force is adjustable.

Abstract: An image forming apparatus has an abnormality detecting device for detecting the abnormality of the sheet, an abnormal sheet containing portion for containing therein the sheet of which the abnormality has been detected, a normal sheet containing portion for temporarily containing therein a normal sheet of which the abnormality has not been detected, and a controlling portion for controlling the image forming portion so that the abnormal sheet is contained in the abnormal sheet containing portion, and that an image formed on the abnormal sheet may be formed on a predetermined subsequent sheet subsequent to the abnormal sheet. The normal sheet between the abnormal sheet and the predetermined subsequent sheet is contained in the normal sheet containing portion after the abnormal sheet is contained in the abnormal sheet containing portion, and the normal sheet contained in the normal sheet containing portion is delivered after the predetermined subsequent sheet has been delivered.

Abstract: In a laser printer capable of printing on both sides of a sheet, alignment or skew of the sheet is corrected with register rollers before printing is performed first on a side of the sheet. The sheet with an image having been formed by a process unit is fed to a re-circulation path for printing on the other side of the sheet. The sheet alignment or skew is corrected in the re-circulation path by a guide plate while the sheet is fed by re-circulation feed rollers. The sheet fed back to the register rollers is fed toward the process unit without being temporarily stopped at the register rollers before printing on the other side of the sheet.

Abstract: An image forming apparatus has a CIS disposed in an area where a sheet passes in such a fashion that read pixels of the CIS are arranged in a direction perpendicular to the feeding direction of the sheet. A part of the read pixels (e.g., 1000 pixels) that corresponds to {fraction (1/7)} of all the read pixels are repeatedly read with a short period (TS) to detect the position of the leading edge of the sheet being fed. After waiting a predetermined period of time after the timing of detection of the leading edge position of the sheet, a laser beam is irradiated onto a photosensitive drum to start writing an image in the subscanning direction. Further, read pixels (e.g., 6000 pixels) that corresponds to {fraction (6/7)} of all the read pixels are repeatedly read with a long period (TL) to detect the position of the side edge of the fed sheet.

Abstract: A print medium feed system comprises a pair of first print medium feed members for feeding a print medium to a print section, a print medium detection section for detecting the print medium, a second print medium feed member for feeding the print medium to the first print medium feed members, and a control section for controlling the first and second print medium feed members. According to the detection by the print medium detection section, the second print medium feed member transports the print medium by a first predetermined distance in the feed direction, then, the first print medium feed members transport the print medium in the feed direction by a second predetermined distance in the feed direction, and then transport the print medium by a third predetermined distance in a backward direction opposite to the feed direction.

Abstract: When initially routing a continuous web along a path, the web walks across the width of the path, and uneven tension occurs causing the web to break in some cases when printing tension is applied thereto. Further, uneven web tension is produced on the right and left of the web by excessive walk control resulting from an excessive deviation of the web from the target position of a walk controller, with the result that the web is crumpled and broken. These problems are solved by maintaining a web tension that is lower than the printing tension until the web position converges on the target position of the walk controller after loading of the web, thereby reducing the amount of correction by the walk controller and the amount of web lost in the preparatory phase before printing, with the result that excellent image quality free from crumple or breakdown is ensured.

Abstract: An image forming apparatus equipped with a first image forming unit, plural second image forming units, and a test-pattern image forming control unit for controlling the first and second image forming units which controls the first and second image forming units to form a test-pattern image, in such a manner that first and second marks of different densities are disposed adjacent to one another, based on test-pattern image data. This test-pattern image data includes first data serving to arrange a plurality of first color lines, which have each a predetermined line width, at a predetermined pitch by the first image forming unit, second data serving to form the first mark overlapping with the plural first color lines by the second image forming units, and third data serving to form the second mark displaced in a direction perpendicular to the plural first color lines.

Abstract: A conveyor system conveys sheets of different widths in a direction normal to the direction of width with an edge of each sheet held along a reference position. The conveyor system includes a drive roller and a nip roller and conveys the sheet with the nip roller urged toward the drive roller under its gravity and a predetermined urging force. The nip roller is heavier at a part on the side of the reference position than at a part on the side opposite to the reference position and is substantially uniform in weight over a predetermined length between the end on the side of the reference position and a part at a predetermined distance from the end on the side of the reference position, and the predetermined urging force is set stronger on the side opposite to the reference position than on the side of the reference position.

Abstract: An image forming apparatus includes: an image forming portion for forming an image; a transferring material conveying belt for conveying a transferring material toward the image forming portion; a driving roller for driving the transferring material conveying belt; a driven roller over which the transferring material conveying belt is looped; and a transferring portion for transferring the image formed by the image forming portion to the transferring material. The transferring material conveying belt is wound and stretched between the driven roller and the driving roller. A rotational axis of the driven roller is different from a rotational axis of the driving roller. Further, a surface of the driven roller includes a layer which has a coefficient of friction lower than a coefficient of friction of a surface of the driving roller.

Abstract: A stalled roll registration system and method includes a mechanism that allows for pivoting deskew action in a pre-registration nip. A ball-on-roll pre-registration transport is used in combination with a stalled roll registration nip. Any initial buckle is depleted rapidly as the body of a sheet straightens out at the registration nip under the influence of the ball-on-belt transport. The method includes the steps of providing a registration nip in a sheet path; providing a ball-on-belt sheet transport for directing a sheet towards the registration nip; feeding the sheet into the registration nip with the ball-on-belt transport; and then pivoting the sheet within the ball-on-belt transport in order to register the sheet against the registration nip.

Abstract: A sheet media position sensor device is disclosed which incorporates a pair of opposed nipped rollers positioned laterally across a sheet media transport path. One roller is electrically conductive while the opposed roller has an electrically conductive resilient coating. The coated roller is insulated at its mid point to divide the coating on the roller into two halves. A DC voltage is applied to the electrical conductive roller with current passing equally through each half of the adjacent coated roller. As sheet media is passed along the transport path and between the two nipped rollers, the sheet media acts as an insulator to reduce the actual contact area and therefore, the current flow between the conductive roller and the coated halves of the nipped roller. This reduced current flow is directly proportionate to the remaining contact area for each half of the roller which specifically identifies the lateral position of the sheet media.

Abstract: A sheet media position sensor device is disclosed which incorporates a pair of opposed nipped rollers positioned laterally across a sheet media transport path. One roller is electrically conductive while the opposed roller has an electrically conductive resilient coating. The coated roller is insulated at its mid point to divide the coating on the roller into two halves. A DC voltage is applied to the electrical conductive roller with current passing equally through each half of the adjacent coated roller. As sheet media is passed along the transport path and between the two nipped rollers, the sheet media acts as an insulator to reduce the actual contact area and therefore, the current flow between the conductive roller and the coated halves of the nipped roller. This reduced current flow is directly proportionate to the remaining contact area for each half of the roller which specifically identifies the lateral position of the sheet media.

Abstract: An image forming apparatus includes an image forming portion for forming an image on a sheet. A separating and feeding portion feeds sheets stacked on a sheet supporting portion one-by-one toward the image forming portion. A sheet conveying portion conveys the sheets fed by the separating and feeding portion. Registration rollers of a variable rotating speed are disposed upstream of the image forming portion with respect to a sheet conveying direction. A sheet conveyance controlling portion causes the registration rollers to effect the conveyance of the sheets at a speed higher than the image forming speed in the image forming portion. Thereafter, the registration rollers are decelerated so as to assume substantially the same speed as the image forming speed at a timing earlier than a latest image forming timing in the image forming portion.

Abstract: An idler roller assembly in an imaging system including a sheet material transport roller system having drive rollers and idler rollers. The idler roller assembly includes a plurality of idler rollers. A plurality of springs are connected to apply respective normal forces to the idler rollers. Pivoting linkages are provided to equalize the normal forces applied to the respective rollers by respective springs. In an embodiment, the plurality of idler rollers includes a first idler roller and a second idler roller. The plurality of springs includes a first spring connected to apply a normal force to the first idler roller and a second spring connected to apply a normal force to the second idler roller. The pivoting linkage includes a first pivoting lever member connected between the first spring and the second spring.

Abstract: Methods and apparatus for reducing or eliminating rotational skew between images formed on opposing sides of a media sheet during duplex printing. An image forming device is configured to print out a test page having a skewing scale formed thereon. A rotational skew correction factor can be determined from the skewing scale and provided to the image forming device, which is configured to alter placement of images on a media sheet in response to the rotational skew correction factor to compensate for rotational skew.

Abstract: The image forming apparatus has exposing device, conveying device, and sheet detecting device for detecting the sheet conveyed by the conveying device, which is disposed between the transferring portion and the conveying device, and control device for judging whether or not it is possible to start exposure by the exposing device before the leading edge of the sheet conveyed by the conveying device reaches the sheet detecting device after the leading edge of the sheet passes through the conveying device and for controlling so that causing the sheet conveyed by the conveying device is stopped in front of the sheet detecting device until it is determined that it is possible to start exposure by the exposing device. In the image forming apparatus, the image forming apparatus starts to form a latent image by the exposing device based on the detection of the sheet by the sheet detecting device.

Abstract: A copy machine having a high accuracy sheet registration system for precise placement of images on each copy sheet. The copy machine includes sensors with charge coupled devices (CCDs) that detect the sheet positions in two dimensions within the machine, and detect sheet arrival times at various positions with the machine. Using this detected information, the copy machine employs a multi-stage process to bring the sheet into contact with a color image moving on a photoreceptor belt, in synchronism with the position and speed of the image on the belt. The copy machine also monitors its own condition and makes predictions about needed preventive maintenance, to instruct personnel to service the machine before the machine fails.

Abstract: To make it possible to transfer an image to an exact position even on a sheet of a maximum size having cutoff margins around a maximum image area of the image-forming module, the invention provides a sheet transport device (5) comprising a registration/transport member (2) provided in a sheet path upstream of a target location (P) for correctly positioning a sheet (1) in a sheet transport direction and transporting it toward the target location (P), and a sheet alignment mechanism (3) provided in the sheet path upstream of the target location (P) for moving the sheet (1) in a direction perpendicular to the sheet transport direction to align the sheet (1) to a reference position predefined for each set of sheet information. The invention also provides an image-forming apparatus incorporating the sheet transport device (5).

Abstract: Conveyance of a sheet is controlled based on a detected skew amount of a conveyed sheet and a result of determination on whether an operation mode set through an operation console is a punching mode or not, thus protecting a user from spending extra time and efforts and extra cost in the event that a sheet skews.

Abstract: An image forming apparatus capable of realizing an improvement in terms of apparatus size and productivity and obtaining a satisfactory image includes a conveyance driving motor M1 for driving conveyance roller pairs 41, 42, and 43, a pre-registration conveyance roller pair 44, and a registration roller pair 10; an image formation driving source for driving photosensitive drums 1a, 1b, 1c, and 1d; and a control unit for controlling the conveyance driving motor M1 and the image formation driving source such that the speed at which a sheet material is conveyed by the conveyance roller pairs 41, 42, and 43, and the pre-registration conveyance roller pair 44 is variable, and that the speed at which the sheet material is conveyed by the registration roller pair 10 is substantially the same as the speed at which the sheet material is conveyed by an image forming device.

Abstract: Color imaging methods and systems allow each color image to be registered in a composite manner. An image-on-image registration controller of an image forming device adjusts the control signals which control the output of image data to reduce or eliminate image registration offsets. In particular, two separate feedback loops are combined to monitor and adjust image registration without going off-line for a set-up procedure. These two feedback loops include a dynamic skew control feedback loop, which monitors and adjusts the edge position of the photoreceptor belt to infer lateral registration, and a direct image registration feedback loop, which monitors and adjusts relative image registration directly. The control signals are adjusted based on a determined image registration offset. The image processing device outputs an image based on the control signals adjusted based on a determined image registration offset.

Abstract: An image forming and paper bundling device and method for bundling the paper that is able to accurately correct the skew of a paper sheet independent of the shape or cutting accuracy of the paper sheet. The image forming apparatus includes an image forming unit for forming an image on the paper sheet, a paper transfer unit for transferring the paper sheet towards the image forming unit, and a skew correcting unit for correcting the skew of the paper sheet being transferred. The skew correcting unit making correction of the paper sheet with reference to an end of the paper sheet that is parallel to the paper transfer direction. The skew correction unit making the correction by urging an end of the paper sheet towards a reference guide as the paper sheet travels through the skew correction unit. A register control portion moves in a direction perpendicular to the path of the paper sheet to register the sheet to a predetermined position.

Abstract: An image forming apparatus of an electrophotographic type including a paper feeding device for separating and feeding piled recording paper, an image forming device for forming the image in order on the fed recording paper, a paper turning-over device for switching back the recording paper and turning over the front and rear tip ends of the recording paper, and a paper re-feeding device for re-feeding the recording paper having the image on one-side surface. In such an apparatus, the both-surfaces image formation can be practiced at the same paper distance, keeping the image forming apparatus small in size and low cost. Furthermore, a conveying roller for switching back the paper and sending out the paper to a printer engine is provided such that the rear tip end of the paper accommodated in the switching-back path becomes the front tip end thereof, and a jogger for performing compensation of lateral registration for the paper is provided in the switch-back path.

Abstract: An image forming apparatus and paper bundling apparatus corrects the skew of a transferred paper sheet highly accurately without being influenced by the shape or cutting accuracy of the paper sheet. The image forming apparatus has ab image forming unit for forming an image on a paper sheet, a paper transfer unit for transferring the paper sheet toward the image forming unit, and a skew correcting unit for correcting the skew of the paper sheet being transferred, with reference to the paper end parallel to the paper transfer direction and for allowing after the correction the paper sheet to reach the image forming unit without performing another skew correction.

Abstract: An image forming apparatus is provided with a plurality of storing units for storing respective recording materials of various sizes; a plurality of feeding members for feeding out the recording materials from each of the storing units; a conveyance path along which the recording materials being fed out by each of the feeding members are conveyed; a plurality of conveying members for conveying the recording materials along the conveyance path; an image forming section for forming an image on the recording materials conveyed along the conveyance path; and a plurality of first regulators provided at respective predetermined positions with respect to corresponding ones of each of the storing units for regulating at least a maximum size of the various sizes of the recording materials while at least at a part of each of the recording materials is fed out from the respective corresponding storing units.

Abstract: The present invention provides an image forming apparatus which comprises a convey belt for bearing and conveying a recording material, an image forming device for forming an image on the recording material born on the convey belt, a detection device for detecting a position of the convey belt in a lateral direction to a conveying direction of recording material by the convey belt, a moving device for shifting the convey belt in the lateral direction to the conveying direction of recording material, and a control device for effecting shifting operations of the moving device every predetermined time by plural timers on the basis of a detection output from the detection device to change a shifting direction of the convey belt in the lateral direction. Further, the control device will control the moving device according to the moving speed of the belt in the lateral direction.

Abstract: The present invention provides a color printer belt meander control method. Starting at a predetermined position of a belt, the belt edge is detected for each small interval of the endless belt. Using a difference between the belt edge position data for the first time and the second time, all skew amounts are calculated. From the skew amounts, a skew correction amount is calculated for each interval. The corrected belt edge position data which has been corrected by the skew correction amount is used to calculate an average belt edge position of the entire belt. The difference between this average belt edge position and a desired belt edge position data is deleted from the corrected belt edge position data. The belt edge position data for small intervals is offset corrected so as to obtain a belt edge learning value. According to the belt edge learning value and the belt edge position data, drive of the steering mechanism is controlled.