An image forming system includes an image forming unit, a sheet folding unit, a sheet discharge tray, and a control unit. For the print job in which a first sheet bundle and a second sheet bundle are discharged onto the sheet discharge tray, the control unit is configured to selectively execute a first image forming mode or a second image forming mode. The first image forming mode is a mode in which a page order is controlled in such a manner that page numbers of sheets included in the second sheet bundle are larger than page numbers of sheets included in the first sheet bundle. The second image forming mode is a mode in which a page order is controlled in such a manner that page numbers of sheets included in the first sheet bundle are larger than page numbers of sheets included in the second sheet bundle.

An image forming apparatus includes a processor, a storage unit, a paper sheet feeder, an image forming unit, and a postprocessing unit. The postprocessing unit performs postprocessing on the recording sheet following image formation by the image forming unit. When a print/postprocessing job in which a plurality of copies is printed and postprocessing is performed on each copy is executed by the print-job execution unit, the postprocessing-position marking unit labels image data for at least the head page of the first copy with predetermined marks respectively in a position where postprocessing is to be performed and in a position where postprocessing is performable. The print-job execution unit, when executing the print/postprocessing job, performs control such that the first copy is printed without postprocessing, an image in which at least the head page has been labeled with the marks is printed, and the print/postprocessing job is temporarily halted.

A sheet stacking tray includes a first conveyor, a second conveyor, a sheet stopper, a first full-load detector, a second full-load detector, and a plurality of motors. The plurality of motors maintain the sheet stopper at a protruding position to block a sheet conveyed by the first conveyor until the first full-load detector outputs a signal indicating that a sheet bundle is fully loaded, shift the sheet stopper to a lowered position to allow the sheet bundle to pass when the first full-load detector outputs the signal indicating that the sheet bundle is fully loaded, drive the first conveyor and the second conveyor together to convey the sheet bundle when the sheet stopper shifts to the lowered position, and stop the second conveyor and drive only the first conveyor, when the second full-load detector detects a leading edge of the sheet bundle.

A system and method of printing involves the use of mixed paper sizes in which the orientation of printing media can be selected to avoid a mixture of paper sheet orientations in the output document when auto tray selection has been selected by a user.

An image forming apparatus includes: a post-processor including a sheet detection circuit detecting a sheet inserted in a sheet insertion opening for manual stapling, a staple mechanism executing stapling processing on the sheet, and a drive circuit actuating the staple mechanism; a post-processing controller operating the drive circuit in response to detection of the sheet; a power circuit supplying power to the drive circuit and another circuit in the apparatus; and a power saving controller shutting off a power supply from the power circuit to the drive circuit and the other circuit and shifting from a normal mode to a power saving mode when a shifting condition is satisfied. Prior to shifting, the power saving controller checks the post-processing controller whether the stapling processing is currently executed, and, when the stapling processing is not currently executed, instructs prohibition of the stapling processing and shifts to the power saving mode.

An imposition device includes an imposing unit that imposes images of plural document pages in a same page order as a pamphlet; a rotation selecting unit that selects whether or not to rotate, by 180 degrees, one of the images that corresponds to a back cover of a pamphlet obtained from a printed material on which the images have been imposed by the imposing unit; and a rotation processing unit that rotates the image that corresponds to the back cover by 180 degrees in a case where rotation of the image that corresponds to the back cover is selected by the rotation selecting unit.

An image processing device includes a processor configured to: obtain image information obtained by reading a sheet that is folded with an intention that a folding line is formed at a position apart from a sheet center position in a specific direction by a predetermined distance, using an image reading device in a state in which a short folded piece of the sheet faces a sensor surface; obtain positions of two edges that are opposite to each other across a folding back of the sheet in the image information; and detect a deviation amount of the folding line based on the positions of the two edges and the predetermined distance.

An image forming system includes an image forming apparatus having an image reading device, and a post-processing apparatus having a manual staple mechanism. The manual staple mechanism is capable of performing staple processing on condition that power is supplied from the image forming apparatus to the post-processing apparatus. The image forming apparatus stops power supply to the post-processing apparatus on condition that a predetermined time has elapsed since reference timing. When the image forming apparatus reads an original with the image reading device, the image forming apparatus determines presence or absence of a staple mark in the original based on a read result. When the image forming apparatus determines that the staple mark is present, the image forming apparatus extends the predetermined time.

An image processing apparatus performs a binding process for binding a plurality of sheets. When a binding unit configured to bind sheets without using a staple performs the binding process, the image processing apparatus adds a mark for identifying a position where the binding process is performed.

A sheet processing device is for binding sheets together. The sheet processing device includes binding units differing from each other in maximum sheet count, the maximum sheet count being a maximum number of sheets that can be bound at a time; a sheet tray configured to hold sheets until all to-be-bound sheets are placed therein, the number of the to-be-bound sheets being a largest one of the maximum sheet counts of the binding units or smaller; and a stacked-sheet-count limiting unit situated in a thickness direction of the sheets held in the sheet tray. The stacked-sheet-count limiting unit is configured to limit the number of sheets held in the sheet tray by varying a distance from a sheet support surface of the sheet tray on which the sheets are placed, depending on one of the binding units by which the sheets held in the sheet tray are to be bound.