A printing apparatus includes: a sheet discharge tray having an upstream portion tilted to extend downward in a direction of gravity; an upper member limiting a height of a space above the sheet discharge tray; a full sensor configured to detect an upstream end of a top sheet of sheets stacked on the sheet discharge tray; a counter configured to count a number of the sheets discharged onto the sheet discharge tray; and a controller. The controller determines whether to stop discharging of the sheets to the sheet discharge tray, based on a detection result of the full sensor upon the sheets to be stacked on the sheet discharge tray including only sheets each with uniform thickness and based on a count value of the counter upon the sheets to be stacked on the sheet discharge tray including a sheet with thickness varying partly.

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 an apparatus body, a post-processing device, a sheet detector, and an indicator. The apparatus body has an internal space open to an outside of the apparatus body. The post-processing device is disposed in the internal space, and has an upper surface forming a sheet ejection tray. The post-processing device is disposed in an internal sheet ejection space as an open space in the apparatus body, and includes an upper surface as a sheet ejection tray. The sheet detector detects a sheet on the sheet ejection tray. The indicator disposed in the post-processing device indicates a sheet on the sheet ejection tray.

An image forming apparatus includes an upper guide unit fixed to the image forming apparatus and configured to guide an upper surface of the sheet discharged by a roller pair, a stack unit provided at a position recessed from an upper exterior unit of the image forming apparatus, and an operation unit including a display unit. The discharged sheets are stacked on the stack unit. The upper guide unit extends more to a downstream side in the discharge direction than the roller pair. The operation unit and the upper guide unit each have a portion overlapping with each other. When viewed in an axial direction of the roller pair, the operation unit and the upper guide unit are arranged at positions through which a straight line orthogonal to a plane passing through axes of rollers of the roller pair and passing through a nip portion of the roller pair passes.

An image forming apparatus sequentially outputs on a discharge tray a sheet medium on which an image based on printing data is formed and includes a counting portion and a control portion. The counting portion counts the number of sheet medium output on the discharge tray. The control portion, when the count number of the sheet medium counted by the counting portion exceeds a prescribed threshold value, issues a warning to a user and/or interrupts output of sheet medium to the discharge tray, infers based on the printing data whether the attended time after the sheet medium is output to the discharge tray until they are removed is short or not, and, after outputting the printing data of which the unattended time is inferred to be short, decrements the count number.

According to examples, an apparatus may include a processor and a memory. The memory may have stored thereon machine readable instructions that when executed by the processor, may cause the processor to determine a job thickness of a print job including sheets, determine an average sheet thickness of the sheets, and determine an average print material coverage on the sheets. The instructions may also cause the processor to identify, based on the determined job thickness, the determined average sheet thickness, and the average print material coverage, a plurality of correction factors to be applied in a calculation of a corrected stack height of print jobs in an output bin and apply the identified plurality of correction factors to a measured stack height in the output bin to calculate the corrected stack height.

An image forming apparatus includes an apparatus body, a post-processing device, a sheet detector, and an indicator. The apparatus body has an internal space open to an outside of the apparatus body. The post-processing device is disposed in the internal space, and has an upper surface forming a sheet ejection tray. The post-processing device is disposed in an internal sheet ejection space as an open space in the apparatus body, and includes an upper surface as a sheet ejection tray. The sheet detector detects a sheet on the sheet ejection tray. The indicator disposed in the post-processing device indicates a sheet on the sheet ejection tray.

A printing system executes printing of a plurality of copies of a document, and includes first and second paper eject trays. The printing system ejects a plurality of paper sheets of the document to the first or second paper eject tray; detects a full state or a near full state being a predetermined number of paper sheets less than the full state; and ejects the paper sheets of a next copy to the first paper eject tray until the first paper eject tray is full and subsequently to the second paper eject tray, in response to detecting that a total ejectable paper sheet number is greater than or equal to the number of paper sheets of the next copy, the total ejectable paper sheet number being obtained by adding together the numbers of paper sheets that can be ejected to the first and second paper eject trays.

A sheet stacking device includes a stacker, a detector, a blower, and a moving device. A sheet is stacked on the stacker. The detector detects a stacking amount of the sheet on the stacker. The blower blows air to the sheet stacked on the stacker. The moving device moves the blower with respect to the stacker based on the stacking amount of the sheet detected by the detector.

A sheet sorting apparatus comprising a first tray, a second tray, a conveyance unit, a tray detection unit, a stacking amount detection unit, and a control unit configured to control the conveyance unit to not convey the sheet to the second tray, in a case where the stacking amount detection unit detects that the amount of sheets reaches the predetermined amount, wherein the control unit is configured to permit the conveyance unit to convey the sheet to the second tray, in a case where the tray detection unit detects that the first tray is detached from the apparatus main body in a state where the stacking amount detection unit detects that the amount of sheets reaches the predetermined amount and conveyance of the sheet to the second tray by the conveyance unit is stopped.