A sheet stacking apparatus includes an ejector, a stacker, a wall, and an upper surface detector. The ejector ejects a sheet, and the stacker stacks the sheet ejected from the ejector. The wall contacts a trailing end of the sheet ejected from the ejector in an ejection direction to align the sheet. The upper surface detector detects an upper surface on a trailing end side of the sheet stacked on the stacker in the ejection direction. When the sheet moves toward the wall, the upper surface detector moves from a home position in which the upper surface detector detects the upper surface of the sheet to a retracted position in which the upper surface detector does not contact the sheet moving toward the wall.

A sheet discharging apparatus includes a discharge portion including a first member configured to apply a force to a first region of a sheet from an upper surface and a second member configured to apply a force to a second region of the sheet from a lower surface, and a contact portion including a first guide surface disposed contactably with the first region and a second guide surface disposed contactably with the second region. The first guide surface is formed such that an angle with respect to a tangential line at a contact point between the first member and the first region of the sheet becomes a first angle. The second guide surface is formed such that an angle with respect to a tangential line at a contact point between the second member and the second region of the sheet becomes a second angle which is smaller than the first angle.

A medium conveying apparatus includes a medium tray, a feed roller, an upper guide, a movement sensor including an arm movably provided by the fed medium on the upper guide and on an upstream side of the feed roller, to generate a movement amount signal corresponding to a movement amount of the arm, a medium sensor to detect a presence of the medium at a predetermined position of the medium tray, a processor to determine whether a feeding abnormality of the medium has occurred based on the movement amount signal, detect a size of the medium placed on the medium tray based on a detection result by the medium sensor, and stop feeding of the medium by the feed roller when the processor determines that the feeding abnormality of the media has occurred and the detected size of the media is equal to or less than a predetermined size.

An image forming apparatus comprises a plurality of sheet detection units, provided at different positions along a sheet width direction, configured to detect the sheet conveyed on a conveyance path. A controller determines, by using the plurality of sheet detection units, a presence or absence of a sheet being conveyed in each of a plurality of regions sectioned in the sheet width direction, and determines, based on input image data, a presence or absence of an image to be formed in each of the plurality of regions. The controller further determines, based on the above determination results, whether or not the image to be formed on the sheet being conveyed is to be formed with a deviation from the sheet, and controls an image forming operation in accordance with this determination result.

A print device comprising an input tray to receive a print media stack, and a load stop arm to manage print media feed, from the input tray, into a media loading path for printing. The load stop arm is to rotate between a media stacking state and a media feed state to manage the print media feed. The load stop arm comprising a trigger protrusion to move from a default position to a trigger position when the load stop arm rotates to the media stacking state in a low stack condition. The low stack condition indicates reduction of print media in the print media stack to an amount below a threshold value. Further, a media detection assembly is in contact with the trigger protrusion to enable generation of a low media signal to indicate the low stack condition when the trigger protrusion moves to the trigger position

Provided is a technique that enables proper sorting of discharged print media by suppressing curling of each of the print media sufficiently. A determining unit determines a curling suppressing operation to be executed such that in a case where sorting operation is executed, the suppressing operation having a higher effect of suppressing curling is executed than in a case where the sorting operation is executed. Then, a print control unit controls a print head to perform printing on print media while executing the suppressing operation determined by the determining unit.

A post-processing device includes a transport path along which a medium printed with liquid ejected by a liquid ejecting portion is transported, an intermediate tray on which the medium is stacked, a first transporting member starting a first transporting operation of transporting the medium upstream in a transport direction after a rear end of the medium passes through the transport path, a rear-end alignment portion that comes into contact with the rear end of the medium transported by the first transporting member and that aligns the medium, a control portion controlling an operation of the first transporting member, and a detection portion detecting a transporting state of the medium in the intermediate tray, in which when the control portion determines, from an output of the detection portion, that the medium reaches the rear-end alignment portion, the control portion regulates the first transporting operation of the first transporting member.

A fastening member detection device includes a contact structure that moves with respect to a medium while contacting the medium, a vibration detector that detects vibration that occur in the contact structure, and a controller that determines whether there is a fastening member that fastens the medium, based on the vibration.

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 printing apparatus includes a displacement member configured to be in contact with discharged print media and be displaced according to the amount of a stack of the print media, and detects the stack amount based on the displacement of the displacement member. The apparatus performs a first or second detection operation based on the detected stack amount. In the first detection operation, after a specified number of print media are discharged with the displacement member positioned at the evacuation position where it does not come into contact with a print medium, the displacement member is brought into contact with the print media to detect the stack amount. In the second detection operation, the stack amount is detected with the displacement member in contact with the print media.