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.

A paper stacking device includes: a stacker on which paper is stacked; a paper ejector that ejects the paper; an aligning plate that is provided on a side of the paper, and aligns a side end of the paper; a paper floating member that is provided in the aligning plate, and supports, from below, the side end of the paper; and a blower that is provided on the side of the paper across the aligning plate, and blows air, wherein the aligning plate includes a blowing opening through which air from the blower is blown, the paper floating member is switched between: a paper floating position; and a retreat position, when the paper floating member is located in the paper floating position, the blowing opening is opened, and when the paper floating member is located in the retreat position, the blowing opening is shielded.

A sheet stacking device is provided with a hopper unit configured to stack a sheet, a feeding unit configured to feed out the sheet to the hopper unit, a distance detection unit configured to detect an inter-sheet distance, in the vertical direction, between a rear end portion of the sheet that is preceding and a tip end portion of the sheet that is subsequent, and an output unit configured to output a behavior stabilization command for the sheet based on the inter-sheet distance.

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.

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 curved baffle positioned above the plurality of rotating discs and the single sheet, an air duct located above the plurality of rotating discs and the single sheet to force an air flow towards the curved baffle, wherein the air flow follows a shape of the curved baffle to create a low pressure zone above the single sheet to keep a trailing edge of the single sheet levitated during completion of the flipping process, and a movable platform to hold a stack of the print media.

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 stacker includes a sheet stacking portion, a guide portion, and an air blower. The sheet stacking portion is configured to stack a sheet bundle. The guide portion is configured to receive a leading end of a sheet conveyed toward the sheet stacking portion and guide the sheet downstream in a sheet conveyance direction in which the sheet is conveyed. The air blower is disposed above the sheet stacking portion and configured to blow air toward the sheet on a downstream side, in the sheet conveyance direction, from a position at which the guide portion receives the leading end of the sheet.

A sheet postprocessing device includes a sheet conveying passage, a sheet tray, an inlet guide, a processing device, and a blowing device. Though the sheet conveying passage, a sheet on which an image has been formed is conveyed. The sheet tray is arranged downstream of the sheet conveying passage and has sheets stacked on it. The inlet guide is arranged at the downstream end of the sheet conveying passage and guides a sheet to the sheet tray. The processing device performs predetermined processing on a sheet stacked on the sheet tray. The blowing device blows air, from the upstream side in the sheet conveying direction, between the top face of the top-most sheet in the sheets stacked on the sheet tray and the bottom face of the subsequent sheet sent from the inlet guide into the sheet tray.

In order to properly suppress a discharge defect corresponding to an image ratio of a sheet, in the case where a coefficient of friction is different according to the image ratio of an image on the sheet, an air blowing section is arranged to blow air toward a downstream side in a transport direction from between a downstream-side end portion of a first stacking section and an upstream-side end portion of a second stacking section. When an image ratio of an image on a sheet by an image forming apparatus is a first value, the air blowing section sets an air quantity blown to the sheet at a first air quantity F1, while when the image ratio is a second value higher than the first value, setting the air quantity blown to the sheet at a second air quantity F2 larger than the first air quantity F1.

A paper stacking device includes: a stacker on which paper is stacked; a paper ejector that ejects the paper; an aligning plate that is provided on a side of the paper, and aligns a side end of the paper; a paper floating member that is provided in the aligning plate, and supports, from below, the side end of the paper; and a blower that is provided on the side of the paper across the aligning plate, and blows air, wherein the aligning plate includes a blowing opening through which air from the blower is blown, the paper floating member is switched between: a paper floating position; and a retreat position, when the paper floating member is located in the paper floating position, the blowing opening is opened, and when the paper floating member is located in the retreat position, the blowing opening is shielded.