Abstract: A sheet processing apparatus that is capable of properly performing fold line processing at a position depending on a sheet bundle. In a sheet processing apparatus, sheets sequentially received from an image forming apparatus are stacked on a bookbinding processing tray to form a sheet bundle. The sheet bundle is folded at the center thereof, and is conveyed to a processing position. A press unit moves along a fold line portion of the sheet bundle to thereby perform flattening processing for flattening the fold line portion by pressing the fold line portion from a direction orthogonal to a thickness direction. A first pressing strength set by a user using the image forming apparatus and the second pressing strength acquired information on the sheet bundle are compared with each other, and the processing position is determined based on a result of the comparison.

Abstract: An image forming system which can recognize the network configuration in real time is provided. The image forming system comprises an image forming apparatus for performing image formation and one or more accessory devices capable of establishing communication with the image forming apparatus via network bus. The image forming apparatus stores identification information which identifies each of the one or more accessory devices. The accessory device detects a communication state of the network bus to notify the image forming apparatus or accessory device which is adjacent of occurrence of communication error not via the network bus. When the occurrence of the communication error of the network bus is notified from the accessory device which is adjacent, the image forming apparatus realizes the network configuration in real time and erases the identification information stored.

Abstract: The image forming system comprises an accessory device and an image forming apparatus, the accessory device for storing device identification information for identifying its own device, and the image forming apparatus to which the accessory device is connected. The image forming apparatus stores the device identification information of the accessory device included in the image forming system. Further, the image forming apparatus receives a participation notification which requires participating in the image forming system from a new accessory device including the device identification information. If the device identification information included in the received participation notification is not stored, the image forming apparatus stores the information. If already stored, the image forming apparatus discards the participation notification.

Abstract: A sheet stacking apparatus for performing post-processing on sheets received from an image forming apparatus and discharging the processed sheets. A stacking tray has the received sheets stacked thereon. A CPU controls a tray lifting/lowering motor to drive the stacking tray to be lifted or lowered. The CPU determines a vertically moving state of the stacking tray. When the stacking tray is not lowered though the tray lifting/lowering motor is controlled to lower the stacking tray, the CPU notifies the image forming apparatus that a job should be suspended. After notifying, the CPU controls the tray lifting/lowering motor to lift the stacking tray. Then, when the stacking tray can be lifted, the CPU notifies the image forming apparatus that the job is to be resumed.

Abstract: Discharging a sheet bundle of a sheet N and a sheet N-1 on preceding sheets already stacked on a stacking tray can cause the already-stacked sheets to be pushed out by the front end of the succeeding sheets. By pressing already-stacked sheets with a bundle pressing member when a sheet bundle of succeeding sheets is discharged, it is possible to reduce the likelihood of the already-stacked sheets being pushed out. Employing the bundle pressing member reduces disturbance of sheet alignment that can occur when a sheet bundle is discharged on already-stacked sheets.

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 sheet processing apparatus capable of determining whether or not a press operation is to be performed on a folded part of a sheet bundle according to the number of sheets of the sheet bundle. If a folding priority mode is not set on a selection screen displayed on a display unit of the sheet processing apparatus, a controller of the sheet processing apparatus determines whether or not the number of sheets of the sheet bundle indicated in sheet bundle information is equal to or larger than a threshold value. The controller sets a press mode in the sheet bundle information to “press,” if the number of sheets of the sheet bundle is equal to or larger than the threshold value, and sets the press mode to “pressless,” if the number of sheets of the sheet bundle is less than the threshold value.

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 post-processing apparatus for performing post-processing on a sheet having an image formed thereon. A stapling section or a scoring section performs processing on a sheet and a sheet bundle. The upper limit value of a sheet count of sheets processable at a time by the post-processing unit is equal to N (N is an integer). A buffer path performs buffer processing for retaining a conveyed sheet, placing the retained sheet and a sheet following the retained sheet one on the other, and conveying the superimposed sheets as a sheet bundle. A CPU controls the buffer path the stapling section or the scoring section such that when the processing is being performed on the sheet or the sheet bundle, the buffer processing is performed on a following sheet, and that the processing is performed on each sheet bundle having been subjected to the buffer processing.

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 sheet stacking apparatus includes an alignment unit configured to align a sheet stacked on a stacking tray in a width direction which is orthogonal to a direction in which the sheet is discharged. The alignment unit includes first and second alignment members configured to move in the width direction. The first and second alignment members come into contact with side ends in the width direction of the sheet stacked on the stacking tray to align the sheet. When a second sheet of a different length in the width direction from that of a first sheet is stacked while shifted in the width direction on the first sheet which is already stacked on the stacking tray, the sheet stacking apparatus prohibits an alignment operation of the alignment unit on the second sheet.

Abstract: A sheet buffer apparatus retains a sheet to be conveyed to a post-processing unit and is configured to perform post-processing for a sheet. The apparatus comprises a buffer unit configured to perform buffer processing to retain a sheet to be conveyed to the post-processing unit and overlay the sheet to be retained and a succeeding sheet, a determination unit configured to determine whether a sheet is inhibited from the buffer processing by the buffer unit, and a control unit configured, when the determination unit determines that the sheet succeeding the sheet to be retained is a sheet for which the buffer processing is inhibited, to control the buffer unit not to perform the retaining of the sheet to be retained.

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 sheet stacking apparatus includes an alignment member to align a sheet stacked on a stacking tray in a width direction perpendicular to a direction in which the sheet is discharged. When stacking a plurality of sheets on the stacking tray, the sheet stacking apparatus lowers the stacking tray, so that a predetermined distance is maintained between the top surface sheet and a sheet discharge port. If the stacking tray is lowered to a predetermined position while the alignment unit is executing an alignment operation at a first position, the sheet stacking apparatus lowers the alignment member to a second position lower than the first position and causes the alignment member to execute the alignment operation at the second position.

Abstract: A sheet stacking apparatus includes a discharge unit, a stacking tray, an acquisition unit, a shift control unit, and an alignment unit. The shift control unit controls a stacking position of a sheet in a sheet width direction in response to shift information acquired by the acquisition unit. The alignment unit aligns a sheet staked on the stacking tray and moves to a position that abuts on a side edge of the sheet in the sheet width direction to align the sheet. The shift control unit controls a stacking position of a second sheet to stack the second sheet on a second position or on a first position depending on where a first sheet is stacked and on shift information of the second sheet.

Abstract: A sheet buffer apparatus retains a sheet to be conveyed to a post-processing unit and is configured to perform post-processing for a sheet. The apparatus comprises a buffer unit configured to perform buffer processing to retain a sheet to be conveyed to the post-processing unit and overlay the sheet to be retained and a succeeding sheet, a determination unit configured to determine whether a sheet is inhibited from the buffer processing by the buffer unit, and a control unit configured, when the determination unit determines that the sheet succeeding the sheet to be retained is a sheet for which the buffer processing is inhibited, to control the buffer unit not to perform the retaining of the sheet to be retained.

Abstract: A sheet stacking apparatus includes a stack unit which includes a first stack tray and a second stack tray which can be individually elevated and is configured to stack a sheet on at least one of the first stack tray and the second tray, and a control unit configured to control the stack unit to stack the sheet in a first stack mode in which the sheet is stacked on at least one of the first stack tray and the second stack tray without being extended over the first stack tray and the second stack tray and a second stack mode in which the sheet is stacked on across the first stack tray and the second stack tray, the control unit capable of selecting the first stack mode and the second stack mode with respect to a same size sheet.

Abstract: Discharging a sheet bundle of a sheet N and a sheet N?1 on preceding sheets already stacked on a stacking tray can cause the already-stacked sheets to be pushed out by the front end of the succeeding sheets. By pressing already-stacked sheets with a bundle pressing member when a sheet bundle of succeeding sheets is discharged, it is possible to reduce the likelihood of the already-stacked sheets being pushed out. Employing the bundle pressing member reduces disturbance of sheet alignment that can occur when a sheet bundle is discharged on already-stacked sheets.

Abstract: A sheet buffer apparatus which retains a sheet to be conveyed to a post-processing unit configured to perform post-processing for a sheet, the apparatus comprises: a buffer unit configured to perform buffer processing to retain a sheet to be conveyed to the post-processing unit and overlay the sheet to be retained and a succeeding sheet; a determination unit configured to determine whether a sheet is inhibited from the buffer processing by the buffer unit; and a control unit configured, when the determination unit determines that the sheet succeeding the sheet to be retained is a sheet for which the buffer processing is inhibited, to control the buffer unit not to perform the retaining of the sheet to be retained.

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.