A recording-medium binding device includes first and second tooth groups. The first tooth group includes first and second tooth rows. The second tooth group includes third and fourth tooth rows. The third tooth row to be engaged with the first tooth row forms, together with the first tooth row, a first tooth row pair. The fourth tooth row to be engaged with the second tooth row forms, together with the second tooth row, a second tooth row pair. A second engaging height in the second tooth row pair is smaller than a first engaging height in the first tooth row pair. A second effective tooth top width in the second tooth row pair is larger than a first effective tooth top width in the first tooth row pair.

An image forming system includes an image forming unit configured to form an image on a sheet and provided in an apparatus body, a first sheet processing device provided in a first housing and configured to perform a first binding processing, without using a needle, on the sheet that is formed with the image and stacked, and a second sheet processing device provided in a second housing that is different from the first housing and configured to perform a second binding processing, using a needle, on the sheet that is formed with the image and stacked. The first housing and the second housing are mounted on the apparatus body. At least a portion of the first housing is positioned within a range exclusively occupied by a rectangular space defined by a maximum outer dimension of the apparatus body. The second housing is positioned outside the rectangular space.

A post-processing apparatus which can respectively balance convenience of user using a manual stapling and convenience of user using an online stapling is provided. The finisher includes a stapler for performing predetermined post-processing on a sheet received and a control unit. The finisher also includes a stapler moving motor which moves the stapler to a position where first processing or second processing is performed. In the first processing, the predetermined post-processing is performed on a sheet which is conveyed from an image forming apparatus. In the second processing, the predetermined post-processing is performed on a sheet which is manually inserted.

A sheet discharging apparatus includes a discharging portion configured to discharge a sheet, a supporting portion configured to support the sheet discharged by the discharging portion, a lifting portion configured to lift and lower the supporting portion, a transmissive sensor configured to output an output signal that changes in accordance with a position of an upper surface of the sheet supported by the supporting portion, a reflective sensor configured to output an output signal that changes in accordance with the position of the upper surface of the sheet supported by the supporting portion, and a controller configured to control the lifting portion and including a first determining portion configured to determine whether or not sheet detection by the transmissive sensor is possible and a second determining portion configured to determine whether or not sheet detection by the transmissive sensor is needed.

A series of conveyance paths to convey a recording medium is formed across a printer and a post-processing device in a printing system. The printing system includes: a detection unit that detects that the post-processing device has entered a predetermined state; and a paper feeding control unit that limits the number of recording media fed to the conveyance path, when it is not detected that the post-processing device has entered the predetermined state, based on the number of recording media conveyable to the post-processing device after the post-processing device enters the predetermined state.

A staple-less binding unit is provided with upper and lower die portions having pluralities of concave and convex teeth engaging with each other. A control portion causes the staple-less binding unit to carry out a binding process of binding a sheet bundle by biting the sheet bundle by the upper and lower die portions and to carry out a cleaning process of engaging the upper and lower die portions in a non-binding process in which no binding process is carried out.

A sheet stacking apparatus including a control portion is configured to execute: a first mode in which the control portion causes a bundle forming portion to form a bundle of sheets including a sheet supported by a first placement portion and a sheet placed on a second placement portion; and a second mode in which a downstream end portion of a bundle of sheets formed in the second mode is positioned upstream of a downstream end portion of a bundle of sheets to be formed in the first mode, and wherein the control portion sets a maximum number of sheets constituting a bundle of sheets which the control portion causes the bundle forming portion to form in the second mode to be smaller than a maximum number of sheets constituting a bundle of sheets which the control portion causes the bundle forming portion to form in the first mode.

Provided is a sheet processing apparatus, including: a placement portion to which a sheet conveyed by a conveyance portion in a conveyance direction is placed; a processing portion configured to perform predetermined processing on a sheet placed on the placement portion, and to be movable in a predetermined moving range; and a control portion configured to control the processing portion to position, at a timing at which a sheet conveyed by the conveyance portion passes through the moving range, from a first position of preventing from interfering with the sheet to a second position of performing the predetermined processing on a preceding sheet having been conveyed by the conveyance portion and placed on the placement portion before the sheet.

A post-processing apparatus for post-processing paper discharged from an image forming apparatus comprises: a paper discharging roller for conveying both first and second paper sequentially discharged from an image forming apparatus to an intermediate loading part; a main paddle part for conveying the first and second paper loaded on the intermediate loading part to a compiling region; a reverse roller for conveying, together with the main paddle part, the first and second paper to the compiling region; and a binding part for processing the first and second paper conveyed to the compiling region, the paper discharging roller allows the first paper to stand by on a standby path, and conveys the first and second paper to the intermediate loading part in a state in which the leading end of the first paper protrudes further than the leading end of the second paper.

Even when a binding process for binding a plurality of sheets without using a staple is performed after performing printing on both faces of the sheets, the binding process can be performed so that the bound sheets are not easily separated. A control method for controlling a printing apparatus, comprises: performing a binding process for binding, without using a staple, a sheet on which an image is printed based on image data; specifying an area where the binding process is to be performed, the area being included in the image data; deleting image data of the specified area; and printing the image on the sheet based on the image data on which deleting is performed.