The present application discloses a post-processing apparatus including a second tray which receives a sheet stack ejected from a first tray, a pushing mechanism including a pushing portion which pushes the sheet stack against the second tray, a motion detector which detects a motion of the pushing mechanism, and a controller including an ejection controller which controls an ejector. When the ejector ejects the sheet stack, the pushing mechanism moves the pushing portion in a first direction away from the second tray. When the ejector finishes ejection of the sheet stack, the pushing mechanism moves the pushing portion in a second direction which is opposite to the first direction. Unless the motion detector detects the motion of the pushing mechanism moving the pushing portion in the first direction when the ejector ejects the sheet stack, the ejection controller executes interruption control of stopping the ejection of the sheet stack.

Post-processing apparatus for performing given process subsequently to image forming process by image forming apparatus is disclosed. Post-processing apparatus includes: first ejector which ejects sheet; first tray which temporarily holds sheet; second tray situated downstream of first tray in ejection direction of sheet; a tray driver which moves second tray downwardly from first height position; blower which forms airstream between second tray and lower surface of sheet; and controller which controls blower and tray driver. Controller includes: blower controller which causes blower to blow air over time period in synchronization with first time period from start to end of sheet ejection by first ejector; and tray controller which causes tray driver to move second tray downwardly from first height position after first time period.

An apparatus is disclosed. For example, the apparatus includes a paper feed to feed print media a single sheet at a time, a plurality of rotating discs, wherein each one of the plurality of rotating discs comprises an elastomer ring to secure a leading edge of the single sheet against a registration wall and initiate a flipping process, a plurality of fans to generate an air flow, wherein the air flow levitates a trailing edge of the single sheet during completion of the flipping process, and a movable platform to hold a stack of the print media.

An apparatus is disclosed. For example, the apparatus includes a paper feed to feed print media a single sheet at a time, a plurality of rotating discs, wherein each one of the plurality of rotating discs comprises an elastomer ring to secure a leading edge of the single sheet against a registration wall and initiate a flipping process, an air duct to force an air flow towards the print media to levitate a trailing edge of the single sheet during completion of the flipping process, and a movable platform to hold a stack of the print media.

A sheet flipping device includes a receiving member for receiving a sheet, a flipping volume being the volume which in operation is defined by the flipping movement of the sheet, and a flipping element for flipping the sheet around an axis of rotation within the flipping volume onto the receiving member. The sheet flipping device further includes an air vortex ring generator having an air vortex ring exit nozzle defining a translational direction of a generated air vortex ring when the generated vortex ring is in operation generated from the air vortex ring exit nozzle. The air vortex ring generator is mounted such that in operation the sheet is urged onto the receiving member by the air vortex ring during the flipping motion of the sheet through the flipping volume. A sheet stacking device and a printing apparatus include the sheet flipping device.

A sheet stacking apparatus includes a discharging portion including a nip portion nipping and conveying a sheet, a stacking portion on which the sheet discharged by the discharging portion is stacked, an air blowing unit configured to blow air toward a lower face of the sheet being discharged by the discharging portion, and an air volume control portion configured to control the air blowing unit such that a volume of the air blown by the air blowing unit is switched from a first air volume to a second air volume which is smaller than the first air volume while the nip portion of the discharging portion is nipping and conveying the sheet to set the volume of the air to the second air volume in a case where a trailing end of the sheet discharged by the discharging portion passes through the nip portion.

A sheet stacking device includes a sheet stacking section, pairs of ejection rollers, an airflow generator, and an airflow guide. The airflow guide has a center exhaust port and paired side exhaust ports. An airflow is blown out from the center exhaust port toward a central part of the lower surface of the sheet in a sheet width direction perpendicular to a conveyance direction of the sheet. Airflows are blown out from the respective paired side exhaust ports toward respective sides of the lower surface of the sheet. An amount of the airflow blown out from the center exhaust port is larger than those of the airflows blown out from the respective paired side exhaust ports.

A buffer means includes a buffer unit that makes paper sheets temporarily stand by and a paper stacking unit that intermittently conveys paper sheets and sucks the trailing edges of the paper sheets to stack the paper sheets stepwise and make them temporarily stand by.

A sheet stacking apparatus includes a discharging portion including a nip portion nipping and conveying a sheet, a stacking portion on which the sheet discharged by the discharging portion is stacked, an air blowing unit configured to blow air toward a lower face of the sheet being discharged by the discharging portion, and an air volume control portion configured to control the air blowing unit such that a volume of the air blown by the air blowing unit is switched from a first air volume to a second air volume which is smaller than the first air volume while the nip portion of the discharging portion is nipping and conveying the sheet to set the volume of the air to the second air volume in a case where a trailing end of the sheet discharged by the discharging portion passes through the nip portion.

One object is to provide a paper sheet handling apparatus in which a paper sheet stacked in a stacking unit is surely pushed toward an opening in the stacking unit. The paper sheet handling apparatus includes a feed unit that feeds a paper sheet, a transport unit that transports the paper sheet fed by the feed unit, a stacking unit that stacks therein the paper sheet transported by the transport unit and has an opening for removing the paper sheet stacked therein, a pushing member that pushes the paper sheet present in the stacking unit toward the opening, a pressing member that presses the paper sheet pushed by the pushing member, and a control unit that controls driving the pressing member based on an operation of the pushing member.