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.

A paper-sheet counting machine (10) includes: a recognition and counting unit (24) configured to count paper sheets; a stacking unit (26) configured to stack therein the paper sheets that have been counted by the recognition and counting unit (24), an opening being provided in a front face of the stacking unit (26); a rotary guide unit (28) provided to the stacking unit (26) and configured to allow the paper sheets that have been counted by the recognition and counting unit (24) to be stacked in the stacking unit (26); a shutter (40) configured to close the opening provided in the front face of the stacking unit (26); a shutter drive unit (50) configured to drive the shutter (40) to open and close the opening provided in the front face of the stacking unit (26); and a control unit (70) configured to control the shutter drive unit (50).

A sheet processing apparatus capable of properly stacking sheets by detecting abnormality of a sheet stacking state during a sheet stacking operation to thereby prevent stack overflow. In the sheet processing apparatus, a conveyed sheet is stacked on a stacking tray. A sheet presence sensor detects a sheet on a sheet stacking surface of the stacking tray. A sheet height reduction sensor detects sheets within a predetermined distance downward from the uppermost surface of sheets stacked on the stacking tray. When the sheet presence sensor detects no sheet, and the sheet height reduction sensor detects a sheet during an operation for discharging a plurality of sheets onto the stacking tray, it is determined that an abnormal stacking state has occurred, and conveyance of a sheet is stopped.

A paper-sheet counting machine (10) includes: a recognition and counting unit (24) configured to count paper sheets; a stacking unit (26) configured to stack therein the paper sheets that have been counted by the recognition and counting unit (24), an opening being provided in a front face of the stacking unit (26); a rotary guide unit (28) provided to the stacking unit (26) and configured to allow the paper sheets that have been counted by the recognition and counting unit (24) to be stacked in the stacking unit (26); a shutter (40) configured to close the opening provided in the front face of the stacking unit (26); a shutter drive unit (50) configured to drive the shutter (40) to open and close the opening provided in the front face of the stacking unit (26); and a control unit (70) configured to control the shutter drive unit (50).

A sheet feeding apparatus includes: a transfer medium loading tray that is movable vertically; a hardware processor configured to control vertical movement of the transfer medium loading tray; an overload detector configured to detect transfer media of a maximum loading amount prescribed for each type of the transfer media; and an intermediate tray position detector configured to detect the transfer medium loading tray being at an intermediate tray position prescribed for each type of the transfer media, wherein the hardware processor is configured to control the vertical movement of the transfer medium loading tray in accordance with a type of the transfer media and on a basis of a vertical position of the transfer medium loading tray, results of detection by the overload detector, and results of detection by the intermediate tray position detector.

A post-processing apparatus comprises a first processing tray on which fed paper is placed; a paper binding section configured to bind a plurality of sheets of paper stacked on the first processing tray into one bundle; a second processing tray which a plurality of paper bundles bound on the first processing tray are sequentially conveyed to and placed on; a paper bundle gluing section configured to coat glue at a given position of the top surface of a first paper bundle placed on the second processing tray before a second paper bundle is placed on the first paper bundle; a pressing section configured to press and bind the first paper bundle with the second paper bundle between which glue is coated; and a control section configured to control the timing for conveying the second paper bundle onto the first paper bundle after the glue is coated.

A post-processing apparatus comprises a first processing tray on which fed paper is placed; a paper binding section configured to bind a plurality of sheets of paper stacked on the first processing tray into one bundle; a second processing tray which a plurality of paper bundles bound on the first processing tray are sequentially conveyed to and placed on; a paper bundle gluing section configured to coat glue at a given position of the top surface of a first paper bundle placed on the second processing tray before a second paper bundle is placed on the first paper bundle; a pressing section configured to press and bind the first paper bundle with the second paper bundle between which glue is coated; and a control section configured to control the timing for conveying the second paper bundle onto the first paper bundle after the glue is coated.

A sheet processing apparatus capable of properly stacking sheets by detecting abnormality of a sheet stacking state during a sheet stacking operation to thereby prevent stack overflow. In the sheet processing apparatus, a conveyed sheet is stacked on a stacking tray. A sheet presence sensor detects a sheet on a sheet stacking surface of the stacking tray. A sheet height reduction sensor detects sheets within a predetermined distance downward from the uppermost surface of sheets stacked on the stacking tray. When the sheet presence sensor detects no sheet, and the sheet height reduction sensor detects a sheet during an operation for discharging a plurality of sheets onto the stacking tray, it is determined that an abnormal stacking state has occurred, and conveyance of a sheet is stopped.

To prevent sheets from being allowed to be delivered after activation of a system when over-stacking has been detected before the activation of the system, a post-processing apparatus includes a stacking tray configured to allow sheets subjected to predetermined processing to be stacked thereon. The post-processing apparatus determines whether or not additional sheets are allowed to be stacked onto the stacking tray based on the number of sheets stacked on the stacking tray. The determination result indicating that the additional sheets are prohibited to be stacked onto the stacking tray is stored in a nonvolatile RAM. The post-processing apparatus determines, after being activated, whether or not the determination result is stored in the nonvolatile RAM, and determines that the additional sheets are prohibited to be stacked onto the stacking tray when the determination result is stored in the nonvolatile RAM.