There is provided a sheet processing apparatus with improved visibility of a sheet bundle discharged without post-processing thereto. The CPU circuit receives the conveyed sheet, drives and controls the sheet-returning paddle, the rack part, the rear end regulation part, the alignment plate and the like and forms sheet bundle comprising of a plural number of sheets as received. Further, the CPU circuit drives and controls the alignment plate when discharging the sheet bundle S from the processing tray, the sheet bundle S exceeding the number of sheets which can be post-processed by the stapler. Therefore, the sheet bundle S which includes sheets equal to the allowable number of sheets for post-processing of the sheet processing unit is discharged to the second discharge position which is different from the first discharge position.

A stacked sheet detection device includes a shaft, at least one first rotor, a second rotor, and a detection sensor. The shaft includes a plurality of attached portions that are formed in alignment along a width direction perpendicular to a discharge direction of sheets. The first rotor is attachable to any one of the plurality of attached portions. The first rotor includes a fitting portion and an arm portion. The fitting portion is configured to be fitted with one of the attached portions. The arm portion is formed to extend from the fitting portion toward the discharge tray and configured to abut on the sheets stacked on the discharge tray. The first rotor is selectively attachable to any one of the plurality of attached portions. The detection sensor is configured to detect that the second rotor rotates in the predetermined rotation direction beyond a predetermined first detection position.

A system and method for adding a print medium digitally to a print system are disclosed. The print system has a control unit for controlling a print job queue and print system parameters, a print engine, an input section, and a receiving section. The method includes receiving the print medium in the input section, loading a test job having prescribed print system parameters in the receiving section, printing a large number of prints of the test job to establish an unwanted deposit of marking material on the side of the stack, and establishing whether or not an unwanted marking material is deposited on a stack height side of the stack. If unwanted deposit is established, then printing a number of blank sheets of the same print medium, adjusting the print system parameters, and returning to printing. If no unwanted deposit is established, approving the use of the print medium.

An image forming apparatus comprises a paper feeding unit which feeds a sheet-shaped recording medium, an image forming unit which forms a toner image on the recording medium fed from the paper feeding unit, a fixing unit which fixes the toner image formed by the image forming unit on the recording medium, a stacking unit which stacks the recording medium on which the toner image is fixed by the fixing unit, a temperature sensor which detects the surface temperature of the recording mediums stacked on the stacking unit and a control unit which determines, according to the printing information of the recording medium, whether or not to feed a new recording medium from the paper feeding unit when the surface temperature of the recording mediums detected by the temperature sensor is above a threshold temperature.

An image forming apparatus is provided including an image forming unit configured to form an image on a print medium, and a printed medium post-processing unit configured to receive and post-process printed media on which an image forming process is completed from the image forming unit. The printed medium post-processing unit selectively comprises one of a first stacker module in which a first amount of post-processed printed media is able to be loaded, and a second stacker module in which a second amount of post-processed printed media is able to be loaded. Therefore, it may be possible to flexibly respond to a loading amount of the printed media necessary for the printed medium post-processing unit.

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.

An image forming apparatus includes a display unit, an image forming unit, a detecting unit to detect whether a sheet is on the tray, a moving unit to cause the tray to ascend and to descend to a lower limit position per a tray sheet amount, and a determination unit to determine that tray descent is interrupted at a position located higher than the lower limit position. At the lower limit position, a screen prompting tray sheet removal is displayed. When the tray descent is interrupted, a screen is displayed to include a tray sheet removal prompt and a notice that an obstacle presents under the tray, an image forming process is stopped, and then the tray is caused to ascend when the sheets are not on the tray and then the image forming process is resumed, even if the obstacle presents under the tray.

An image forming apparatus includes a display unit, an image forming unit, a detecting unit to detect whether a sheet is on the tray, a moving unit to cause the tray to ascend and to descend to a lower limit position per a tray sheet amount, and a determination unit to determine that tray descent is interrupted at a position located higher than the lower limit position. At the lower limit position, a screen prompting tray sheet removal is displayed. When the tray descent is interrupted, a screen is displayed to include a tray sheet removal prompt and a notice that an obstacle presents under the tray, an image forming process is stopped, and then the tray is caused to ascend when the sheets are not on the tray and then the image forming process is resumed, even if the obstacle presents under the tray.

Even when descending of a sheet stacking unit is interrupted by an obstacle, sheet stacking operation is resumed in a range in which the sheet stacking unit is movable.

A system and method for adding a print medium digitally to a print system are disclosed. The print system has a control unit for controlling a print job queue and print system parameters, a print engine, an input section, and a receiving section. The method includes receiving the print medium in the input section, loading a test job having prescribed print system parameters in the receiving section, printing a large number of prints of the test job to establish an unwanted deposit of marking material on the side of the stack, and establishing whether or not an unwanted marking material is deposited on a stack height side of the stack. If unwanted deposit is established, then printing a number of blank sheets of the same print medium, adjusting the print system parameters, and returning to printing. If no unwanted deposit is established, approving the use of the print medium.