Abstract: Provided is an image forming system including a feed tray, a printer unit, a first post-processing unit that performs first post-processing accompanying at least a change in a sheet size, a second post-processing unit that performs second post-processing other than the first post-processing, and a control unit that controls setting and performing feeding, outputting, and the post-processing of the sheet. In a case where the first post-processing and the second post-processing are set, the control unit acquires a feeding sheet size of a sheet fed from the feed tray, calculates a sheet size after the first post-processing based on the acquired feeding sheet size, and determines whether the set post-processings can be performed based on the calculated sheet size and a sheet size that can be processed by the second post-processing.

Abstract: An image processing apparatus prints an image on a sheet and controls one of a plurality of binding units to bind the sheets on which the images are printed. The image processing apparatus further enables designation of a binding process to be used to bind the sheets, and provides notification of the number of sheets that can be bound by the designated binding process and the number of sheets that can be bound by a non-designated binding process.

Abstract: A mechanism capable of changing an upper limit number of sheets for a post-process is provided. To achieve this, a control method for controlling a sheet processing apparatus which performs the post-process for the sheets on which images are formed, comprising: storing, in a storage unit, the upper limit number of sheets to which the post-process can be performed; and changing the upper limit number of sheets stored in the storage unit is provided.

Abstract: When information about weight of a sheet indicates weight less than a predetermined weight, a sheet stacking apparatus configured to align sheets to be stacked on a stacking tray discharges the sheet onto the stacking tray while overlapping the sheet with another sheet by an overlapping unit, and, when the information about the weight of the sheet indicates weight not less than the predetermined weight, the sheet stacking apparatus discharges the sheet onto the stacking tray without overlapping the sheet with another sheet by the overlapping unit.

Abstract: A translatable media height sensor assembly for measuring a media stack in an imaging forming device. The assembly includes a support and drive and insertion assemblies mounted thereon. Insertion assembly includes a translatable plunger having mounted thereon a sensor and a translatable probe. At a home position the sensor is actuated by a flag on the support placing sensor output in a first state. During measurement, drive assembly translates insertion assembly toward a media stack and the sensor output changes to a second state and a counter is started. The probe encounters the media stack and stops while plunger and sensor continue to translate with the probe engaging the sensor causing the sensor output to again change state and stop the counter. The insertion assembly retracts back to the home position where the flag actuates the sensor causing the sensor output to change state.

Abstract: A post-processing apparatus includes a processing tray, a conveyance portion, a staple unit, an operation portion, a mode switching portion, a cover, and an open/close detection portion. The staple unit, which has an automatic mode and a manual mode as processing modes for stapling processing, executes stapling processing for a paper sheet conveyed to the processing tray by the conveyance portion in the automatic mode, and executes stapling processing for a paper sheet stacked on the processing tray by a user in the manual mode. The cover is attached in an openable and closable manner so as to cover the operation portion when closed, and expose the operation portion when opened. While the open/close detection portion is detecting that the cover is opened, when the operation portion has received an operation for switching to the manual mode, the mode switching portion switches the automatic mode to the manual mode.

Abstract: A sheet post-processing apparatus that is capable of aligning a sheet bundle accurately even if sheet types like sheet sizes are different, and is capable of setting a reference position depending on a selected finish. A conveyance unit conveys a sheet. A sheet stacking unit stacks sheets conveyed by the conveyance unit as a sheet bundle. A stapler applies a staple process to the sheet bundle stacked on the sheet stacking unit. A position determination unit determines a staple position at which the staple process is applied to the sheet bundle. An alignment unit aligns the sheets stacked on the sheet stacking unit in a direction perpendicular to a sheet conveyance direction with respect to one of both sides parallel to the sheet conveyance direction. The alignment unit determines the one side as a reference side depending on the staple position determined by the position determination unit.

Abstract: A sheet processing device includes an exit tray and a sheet alignment mechanism. On the exit tray, ejected sheets or ejected sheet sheaves subjected to stapling are stacked. When at least a sheet is ejected, the sheet alignment mechanism aligns the sheets in a manner to be in contact with and catch opposite ends of the sheets stacked on the exit tray from a base end side of the exit tray. When a sheet sheaf is ejected, the sheet alignment mechanism comes in contact with a plurality of points on a topmost surface of the sheet sheaves stacked on the exit tray to detect a height difference between the plurality of points.

Abstract: A sheet processing apparatus includes: a binding unit that sandwiches and binds a plurality of sheets by using a convex portion and a concave portion; a moving unit that moves at least one of the convex portion and the concave portion; a drive unit that drives the moving unit; and a control unit that controls the drive unit so that a state in which the binding unit sandwiches the plurality of sheets at a predetermined pressing force by using a driving force from the drive unit is retained for a predetermined time period, and so that the one of the convex portion and the concave portion is moved in a direction away from the another of the convex portion and the concave portion after the predetermined time period has elapsed.

Abstract: A pressing portion is lowered to press from above sheets or a sheet bundle discharged onto a discharge tray, and a moving portion configured to lower the pressing portion is controlled so that, in a case where the sheet bundle is discharged onto the discharge tray, the pressing portion exerts a pressing force greater than a pressing force in a case where the sheets are discharged onto the discharge tray.

Abstract: During stapling operations: connectors disconnect a compiler platform from an elevator platform; an ejector structure is maintained in a fully retracted position to allow a stack of sheets to be within a stapling area; a stapling device staples the stack of sheets in the stapling area; the ejector structure moves the stapled set of sheets to the elevator platform; and the elevator platform moves in a downward direction after the ejector structure moves the stapled set of sheets to the elevator platform. During non-stapling stacking operations: the connectors connect the compiler platform to the elevator platform; the ejector structure is maintained in a middle position between a fully retracted position and a fully ejected position to prevent the sheets from entering the stapling area; and the elevator platform and the compiler platform move together in the downward direction as additional sheets are added to the stack of sheets.

Abstract: A sheet processing apparatus capable of shortening a time period required to determine whether or not a sheet bundle has been normally stapled, while suppressing an increase of apparatus size and an increase of apparatus manufacturing cost, and capable of stacking sheet bundles on a sheet discharge tray such that sheet bundles not normally stapled can be distinguished from normally stapled sheet bundles. When the absence of staple is detected in a sheet bundle by one or both of staple detecting sensors, sheet bundles starting from a sheet bundle to be discharged next are shifted on a processing tray, whereby a sheet discharge position of the next and subsequent sheet bundles on the sheet discharge tray is changed.

Abstract: An image forming system which is capable of, when a manual stapling process is to be carried out on sheets, reducing waiting time for a user and decreasing power consumption. The image forming system has an image forming apparatus, which forms images on sheets, and a sheet post-processing apparatus. When the sheet post-processing apparatus is to shift into a power-saving state, a movable stapler is moved to a manual stapling position. When it is detected that sheets have been set into a sheet setting unit in a state in which the image forming apparatus and the sheet post-processing apparatus have shifted into the power-saving state, the image forming apparatus is held in the power-saving state, and the sheet post-processing apparatus is returned from the power-saving state.

Abstract: A sheet post-processing apparatus capable of stably stopping a clamping member at a predetermined target position (holding position), of performing post-processing regardless of thickness of a sheet bundle. A holding member is used for holding a sheet bundle. A moving unit moves the holding member between a predetermined reference position and a predetermined holding position at which the holding member holds the sheet bundle. A sheet post-processing unit performs post-processing on the sheet bundle held by the holding member. A control unit configured to, when the holding member is moved from the reference position and is stopped at the holding position by the moving unit, decelerate a moving speed of the moving unit, before performing a stopping process of the moving unit, such that a deceleration rate of the moving speed is smaller as a thickness of the sheet bundle is larger.

Abstract: A sheet processing apparatus is disclosed which includes front and back trailing-end reference fences that are movable and on which the sheet trailing-end abuts to align the sheet trailing-end; a side-stitching stapler that moves along the sheet trailing-end and binds a bundle of sheets aligned; a length-direction moving mechanism that moves the trailing-end reference fences in a sheet conveying direction; and a position changing unit that drives the length-direction moving mechanism to change the position of one of the trailing-end reference fences in the sheet conveying direction relative to the position of the other one. The front and back trailing-end reference fences are moved to change binding positions such that the distances from the sheet trailing-end to staple positions are made equal in front-side binding and in back-side binding.

Abstract: A sheet processing device provided with a stacking unit configured to stack thereon one or more conveyed sheets, a staple unit configured to staple a bundle of sheets stacked on the stacking unit, a moving unit configured to move the staple unit to a staple position, and a projecting and retrieving unit configured to project and retrieve the stacking unit in a space overlapped with a motion space for the staple unit to move therein.

Abstract: An image forming apparatus includes a punching time measuring unit, a stapling time estimating unit, and a sheet-bundle interval time setting unit. The punching time measuring unit measures a punching processing time to perform punching processing. The stapling time estimating unit calculates an estimated stapling processing time to perform stapling processing by using the punching processing time measured by the punching time measuring unit. The sheet-bundle interval time setting unit sets a sheet-bundle interval time, which is a time from when the last sheet forming a sheet bundle subjected to the punching processing is fed until when the first sheet forming a subsequent sheet bundle subjected to the punching processing is fed.

Abstract: A post-processing apparatus includes a processing tray, a conveyance portion, a staple unit, an operation portion, a mode switching portion, a cover, and an open/close detection portion. The staple unit, which has an automatic mode and a manual mode as processing modes for stapling processing, executes stapling processing for a paper sheet conveyed to the processing tray by the conveyance portion in the automatic mode, and executes stapling processing for a paper sheet stacked on the processing tray by a user in the manual mode. The cover is attached in an openable and closable manner so as to cover the operation portion when closed, and expose the operation portion when opened. While the open/close detection portion is detecting that the cover is opened, when the operation portion has received an operation for switching to the manual mode, the mode switching portion switches the automatic mode to the manual mode.

Abstract: A sheet post-processing apparatus which is capable of preventing a stapling position and a folding position from being out of alignment when a stapling process is carried out. A sheet bundle, which is stacked in a housing guide, is stapled by a stapler using a staple at the stapling position. The sheet bundle is folded at a position of the staple after the stapling. After the stapling, the sheet bundle is moved from the stapling position to the folding position. During the movement, the staple is detected using a staple sensor disposed at a predetermined location between the stapling position and the folding position. Based on a moving distance of the sheet bundle before the staple is detected after the stapling process, a position of the sheet bundle with respect to the stapler for stapling on a subsequent sheet bundle is corrected.

Abstract: According to one embodiment, a sheet processing device includes a jogger fence configured to carry out a crosswise direction alignment to a stack of image formed sheets ejected from an image forming apparatus, a rear end fence acting as a lengthwise reference edge, a stapling device configured to staple the aligned sheet stack, a discharge belt configured to move the stapled sheet stack to a sheet ejection tray, and a controller to control movement of the jogger fence during the sheet stack being moved by the discharge belt so as to move the jogger fence more than once between a position where the jogger fence does not contact the edge of the sheet stack and a position where the jogger fence pressing contact the edge of the sheet stack.

Abstract: When information about weight of a sheet indicates weight less than a predetermined weight, a sheet stacking apparatus configured to align sheets to be stacked on a stacking tray discharges the sheet onto the stacking tray while overlapping the sheet with another sheet by an overlapping unit, and, when the information about the weight of the sheet indicates weight not less than the predetermined weight, the sheet stacking apparatus discharges the sheet onto the stacking tray without overlapping the sheet with another sheet by the overlapping unit.

Abstract: A post-processing device includes a processing tray on which sheets are to be stacked, a transport portion for transporting, a sheet introduced through an introduction port, a turn-aside portion for turning aside the sheet to delay arrival of the sheet at the processing tray, and a delivery mechanism for delivering the sheets stacked on the processing tray to a delivery tray on a boundary between copies. When a remaining number of sheets of one copy unstacked on the processing tray exceeds a maximum number of stacked sheets that is an amount of sheets stackable on the processing tray, the delivery mechanism delivers a sheet stack of the one copy a plurality of times so as to avoid delivery of only one sheet on a last page of the one copy, and the turn-aside portion turns aside a sheet on a first page to be stacked after delivering the sheet bundle.

Abstract: A sheet processing apparatus which makes it possible to detect staples at a plurality of points by a smaller number of sensors. The sheet processing apparatus shifts a stapler along an edge of a sheet bundle. The stapler has a staple detection sensor attached thereto. The staple detection sensor detects a staple driven into the sheet bundle while passing by a staple detection position during shifting of the stapler. The stapler sequentially performs stapling at a first position and a second position along the edge of the sheet bundle, and is then shifted to a standby position. During a time period from completion of the stapling at the first position to completion of the shifting of the stapler to the standby position, the staple detection sensor detects presence or absence of a staple at each of the first position and the second position.

Abstract: The present invention prevents a succeeding sheet from being caught in holes of preceding punched sheets.

Abstract: A sheet processing device for stacking one or more sheets temporarily on a stacking unit, and stapling the sheets by a stapling unit after aligned by an alignment unit. The device includes a shift unit that shifts the sheet in both a sheet conveying direction and a direction orthogonal to the sheet conveying direction, and a control unit that controls a shift amount of the shift unit so that an alignment distance of a width direction alignment unit to align the sheet in the direction orthogonal to the sheet conveying direction is constant regardless of a staple position and a sheet size, when stacking the sheets on the stacking unit.

Abstract: In a provided apparatus, an upper roller to be engaged with a sheet upper face and a lower roller to be engaged with a sheet lower face are arranged at a sheet discharging port in a manner capable of being pressure-contacted and being separated, the upper roller is formed with a large-diameter soft roll face and a small-diameter hard roll face, and a pressurization force of roller lifting-lowering means with which the upper roller is pressure-contacted to and is separated from the lower roller is switched to be high or low.

Abstract: In an apparatus structure having a sheet discharge mode to store sheets at a stack tray from a sheet discharging path and a sheet discharge mode to store binding-processed sheet bundles with collating and stacking, sheet holding means is arranged above a sheet placement face of the stack tray as a sheet pressurization force being variable in two steps, and then, the pressurization force of the sheet holding means is adjusted in two steps in accordance with the sheet discharge mode for storing sheets at the stack tray.

Abstract: An image forming system including a control section provides control in such a way that, the ring binder of the size determined for the first set of copies is adopted so that ring binding is performed for a second set of copies or copies thereafter in a case of executing a job for ring binding of a plurality of copies. When at least one of a status change in the sheet feed section, a main power source being turned off, or a change in a job ticket is occurred from a suspension to a resumption of the job, since the thickness of a bundle of sheets may change, the thickness measuring section is caused to measure the thickness of the bundle in a first set of copies subsequent to resumption. And the control section judges continuation or suspension of a job.

Abstract: A control apparatus that controls a stapling unit configured to staple sheets includes a control unit configured to determine a turning-over direction of sheets to be stapled by the stapling unit and to determine a maximum number of staplable sheets according to the determined turning-over direction.

Abstract: A post-processing device includes a transport section transporting a sheet transported at a predetermined speed from an upstream side toward a downstream side; a load section on which the transported sheet is loaded; an aligner aligning the loaded sheet; an alignment controller performing control such that the aligner performs the alignment process on the sheet transported from the transport section to the load section for every predetermined number of sheets; and a transport controller controlling the transport section by causing the transport section to transport the sheet at a reduced speed for the every predetermined number of sheets so that the sheet transported at the reduced speed reaches the load section after the aligner completes the sheet alignment process that is performed on a previous sheet transported immediately prior to the sheet after the previous sheet is loaded on the load section.

Abstract: A sheet processing apparatus that forms asperity on a sheet bundle so as to bind the sheet bundle, has a pair of rotating members having a concave and convex portions on the outer periphery, a moving portion that moves at least one of the pair of the rotating members so as to nip the sheet bundle by the pair of the rotating members or release the sheet bundle, and a controlling portion that controls the moving portion to allow the pair of rotating members to rotate with a concave portion of one rotating member and a convex portion of the other meshed with each other while nipping the sheet bundle or releasing the sheet bundle.

Abstract: An image forming apparatus that enables to execute a bookbinding process for sheet bundles without decreasing productivity. The image forming apparatus is connected to a bookbinding apparatus having a bookbinding unit that binds a book by attaching a ring to a punch hole and a buffer unit that performs a buffering process to convey sheets in piles so that sheets for a next sheet bundle are not ejected onto a sheet bundle that is being processed by the bookbinding unit. A determination unit determines whether a sheet is a type that is prohibited from buffering. A control unit adjusts an ejection order so that the sheet of the type that is prohibited from buffering is not ejected within the predetermined number of sheets from the first sheet of sheets that constitute the sheet bundle, when the determination unit determines that the sheet is the type that is prohibited from buffering.

Abstract: A sheet processing apparatus includes a punch motor, an actuator which rotates by driving of the punch motor, a punching blade which punches a sheet by driving of the actuator, and a controller which controls the driving of the punch motor so that approach run is gained, if a thickness of the sheet exceeds a threshold, in a rotating direction of the actuator in which the punching blade does not move at the beginning of the driving of the punch motor.

Abstract: A sheet processing device includes a stacking unit that is used to stack a bundle of sheets that are placed upon each other with first edge portions of the sheets being aligned with each other; a first binding unit that binds the first edge portions of the bundle of sheets stacked upon the stacking unit; a second binding unit that is provided integrally with the first binding unit in a direction along the first edge portions of the bundle of sheets stacked upon the stacking unit, and that binds the first edge portions by a binding method differing from a binding method of the first binding unit; and an angle changing mechanism that is capable of changing an angle of the first binding unit with respect to the bundle of sheets when binding the first edge portions with the first binding unit.

Abstract: A printing control apparatus configured to control a binding unit configured to perform a binding processing for binding sheets without using a staple includes a control unit that controls the biding unit to divide sheets subjected to printing into sheet groups in units of a number of sheets bindable by the binding unit, and to apply the binding processing to each of sheet groups or controls another binding unit to bind the sheets subjected to printing using a staple.

Abstract: A sheet processing apparatus includes a pair of first aligning members movable in a sheet conveyance direction and a sheet width direction, a pair of second aligning members to align lateral sides of a bundle of sheets, a stapler movable in the sheet width direction to staple a trailing end portion of the bundle, a driving unit to move the first aligning members, and a controller. The first aligning members include a stack portion to contact and support a trailing edge of the bundle. When the stapler staples the bundle at two positions symmetrically relative to a center position in the sheet width direction, the controller selects either first positions inside the two stapled positions or second positions outside the two stapled positions in accordance with multiple stapling-related variables, and the first aligning members are set at the selected positions to align the trailing edge of the bundle.

Abstract: The present invention relates to a sheet stack thickness estimating device including a driving device, a first connecting rod, a second connecting rod, a pressing part and a sensor. The driving device provides a motive force to the sheet stack thickness estimating device so as to drive the first connecting rod moved horizontally for rotating the second connecting rod, so that the pressing part presses the sheets on the paper tray. By detecting if the signal generated by the sensor is blocked by the first connecting rod, the thickness estimating device can judge if the thickness of the sheets exceeds a predetermined value.

Abstract: A control apparatus obtains information identifying sheets stored in an MFP to be caused to perform printing for printing a printed object to be subjected to jacketed book binding, wherein this information is stored in the MFP. The control apparatus stores thicknesses of respective paper sheets as information about paper sheets. From this information and from the information obtained from the MFP, the control apparatus creates a table indicative of the correspondence between the respective paper sheets stored in the MFP and their thicknesses. Further, on receiving a selection of paper sheets to be used for printing for the printed object and a number of these paper sheets, the control apparatus determines a thickness of each paper sheet by making a reference to the table and calculates the spine jacket width by multiplying the thickness by the number of paper sheets.

Abstract: A sheet processing apparatus includes: a sheet stacking unit on which sheets are accommodated and stacked as a sheet bundle; an aligning member that is movable along a trailing end, in a conveying direction, of the sheet bundle stacked on the sheet stacking unit and that aligns the trailing end of the sheet bundle in the sheet conveying direction by abutting thereon; a binding unit that moves along the trailing end of the sheet bundle in the sheet conveying direction and binds the aligned sheet bundle; and a moving unit that moves the aligning member in the sheet conveying direction. A distance from the trailing end of the sheet bundle in the sheet conveying direction to a binding position is adjusted by moving the aligning member in the sheet conveying direction.

Abstract: A sheet processing apparatus includes: a correcting unit that corrects alignment of a sheet; a post-processing unit that performs post-processing on the sheet after the correcting unit corrects the alignment of the sheet; and a creasing unit that forms a crease on the sheet after the correcting unit corrects the alignment of the sheet.

Abstract: A sheet processing apparatus includes a support unit on which sheets are stacked together as a sheet stack, first and second binding units that respectively perform first and second binding processes to bind the sheet stack as first and second sheet stacks, a transporting unit that transports the first and second sheet stacks toward first and second paths, respectively, which are in opposite directions, a reversing-and-transporting unit disposed at the second path to transport the second sheet stack such that upper and lower sides thereof are reversed, a first transported-sheet-stack support unit that is disposed at the first path and on which the first sheet stack transported by the transporting unit is placed, and a second transported-sheet-stack support unit that is disposed at the second path and on which the second sheet stack reversed and transported by the reversing-and-transporting unit is placed.

Abstract: A sheet processing apparatus includes a staple processing portion and a sheet stacking portion on which a sheet is stacked and abutted. The sheet processing apparatus also includes a fold processing portion, a conveyance guide member, an end part processing portion to perform an end part process to the folded end part, and a controlling portion. After a stapling process is performed, the fold processing portion folds the sheet bundle in two to create a folded sheet bundle having a folded end part between a first surface and a second surface. The conveyance guide member guides the folded sheet bundle with the folded end part as a leading end while the first surface slides against the conveyance guide member. The controlling portion controls the positioning member such that the stapling position is moved, by a predetermined distance, to an area on the sheet bundle that will become the second surface.

Abstract: A method and device for stitching printed products with a stitching machine, which includes a stitcher head and a bending device, which travel concomitantly with each printed product as it is conveyed in a travel direction during the stitching operation. The bending device is positioned first in a first position, which corresponds to the thickness of the printed products and is a certain distance away from the stitcher head in the direction transverse to the travel direction. Before a printed product is introduced, its thickness is determined and compared with a predetermined limit value; and, if this limit value is exceeded, the bending device is brought into a predetermined second position, which is farther away than the first position from the stitching head. After the printed product has been introduced, the bending device is moved back into the first position, and the wire stitch is driven into the printed product.

Abstract: In an image forming apparatus, a distance adjusting unit adjusts an inter-unit distance between a contact unit and an image carrier by moving the image carrier or the contact unit by applying an opposing force to the image carrier or the contact unit against a biasing force applied by a biasing unit based on thickness information of a recording sheet acquired by a thickness-information acquiring unit and data indicating a relationship between the thickness information and an inter-unit distance change amount stored in a data storage unit.

Abstract: A sheet processing apparatus includes: a punch portion which is capable of punching a hole of a different type in a sheet; a sheet stack portion on which a punched sheet is stacked; and a determining portion which determines the hole type; wherein stack limit number of sheets to be stacked on the sheet stack portion is changed in accordance with the hole type determined by the determining portion.

Abstract: The production line according to the present invention is provided with a pressurization measurement apparatus adjacent to a press-working apparatus, a temporary laminate assembly worked and laminated by a press in the press-working apparatus is sent to the pressurization measurement apparatus, and a laminate assembly is produced by being pressurized and being subjected to regular caulking by a hydraulic servo press of the pressurization measurement apparatus. At this time, the lamination height of a regularly caulked laminate assembly is measured by a linear scale secured at the pressurization measurement apparatus.

Abstract: To provide a post-processing system for enabling a sheet prepared in a different printing apparatus to be mixed and undergo post-processing when the post-processing apparatus performs bookbinding finish on sheets with images formed thereon, a collecting means is provided in a post-processing section for performing post-processing on image-formed sheets, and is configured to enable a bunch of sheets to be manually set from the outside, a control section is provided with operating means for outputting a set finish signal such that the sheets have been set manually in the collecting means, and it is configured when a mode selecting means selects a mixing post-processing mode, the control section performs the post-processing on a bunch of sheets by post-processing means using the set finish signal from the operating means.

Abstract: A sheet processing apparatus which makes it possible to detect staples at a plurality of points by a smaller number of sensors. The sheet processing apparatus shifts a stapler along an edge of a sheet bundle. The stapler has a staple detection sensor attached thereto. The staple detection sensor detects a staple driven into the sheet bundle while passing by a staple detection position during shifting of the stapler. The stapler sequentially performs stapling at a first position and a second position along the edge of the sheet bundle, and is then shifted to a standby position. During a time period from completion of the stapling at the first position to completion of the shifting of the stapler to the standby position, the staple detection sensor detects presence or absence of a staple at each of the first position and the second position.

Abstract: A sheet processing apparatus that forms asperity on a sheet bundle, which includes plural sheets, so as to bind the sheet bundle, includes: a pair of rotating members having a concave and convex portions on the outer periphery; a moving portion that moves at least one of the pair of the rotating members so as to nip the sheet bundle by the pair of the rotating members or release the sheet bundle; and a controlling portion that controls the moving portion to allow the pair of rotating members to rotate with a concave portion of one rotating member and a convex portion of the other meshed with each other while nipping the sheet bundle or releasing the sheet bundle.

Abstract: A method includes causing a stacking device having a first stacking unit and a second stacking unit to stack sheets of a small size on the first stacking unit or the second stacking unit and to stack sheets of a large size over the first stacking unit and the second stacking unit, and controlling the stacking of sheets by restricting stacking of the sheets of the large size on the sheet of the small size when the sheets of the small size are stacked on at least one of the first stacking unit and the second stacking unit.