A sheet stacker includes a sheet ejector, a sheet stack portion, and air blowers. The sheet ejector ejects a sheet. The sheet stack portion stacks the sheet ejected by the sheet ejector. The air blowers blow air from blow ports toward the sheet ejected from the sheet ejector. Each of the air blowers includes an air generator, an air guide, a first blow portion, a second blow portion, and a switcher. The air generator generates the air. The air guide guides the air to each of the blow ports. The first blow portion blows the air toward the sheet. The second blow portion blows the air in a direction different from a direction in which the first blow portion blows the air. The switcher performs switching so that the air guide guides the air to one of the first blow portion and the second blow portion.

A sheet processing apparatus includes a sheet processing unit that processes a sheet placed on a placing tray, a discharge roller that discharges the sheet processed on the placing tray to a stacking tray, a conveyance roller that discharges a sheet to the placing tray or conveys a subsequent sheet from upstream to downstream of the discharge roller and switchback-conveys the subsequent sheet upstream again, and a standby path (branch path) that keeps the sheet switched back by the conveyance roller on standby. The subsequent sheet is conveyed to a downstream side of the discharge roller by the conveyance roller and then returned to an upstream side again by switchback conveyance. During the switchback conveyance, the discharge roller nips and discharges the sheets on the placing tray to the stacking tray.

A sheet processing apparatus includes an intermediate tray on which a sheet is to be stacked, a stapler to execute stapling processing on the stacked sheet, a discharge tray on which the sheet subjected to the stapling processing by the stapler and discharged from the intermediate tray is to be stacked, a control unit, and a shift unit. The shift unit may shift the sheet to a position on the intermediate tray, wherein the position is outside of a range in which the stapling processing is to be executed. In a state where a first sheet and a second sheet are stacked on the intermediate tray and the second sheet is subject to the stapling processing, the control unit causes the shift unit to shift the first sheet on which the stapling processing is not executed, and causes the stapler to execute the stapling processing on the second sheet.

A sheet stacking apparatus including a control portion is configured to execute: a first mode in which the control portion causes a bundle forming portion to form a bundle of sheets including a sheet supported by a first placement portion and a sheet placed on a second placement portion; and a second mode in which a downstream end portion of a bundle of sheets formed in the second mode is positioned upstream of a downstream end portion of a bundle of sheets to be formed in the first mode, and wherein the control portion sets a maximum number of sheets constituting a bundle of sheets which the control portion causes the bundle forming portion to form in the second mode to be smaller than a maximum number of sheets constituting a bundle of sheets which the control portion causes the bundle forming portion to form in the first mode.

A system for presenting media sheets incudes a finisher output bin assembly. The finisher output bin assembly includes a translatable output floor, and a guide substrate coupled to the translatable output floor to guide the translatable output floor relative to the guide substrate in at least one coordinate direction. The finisher output bin assembly includes an output structure mechanically coupled to the translatable output floor to drive the translatable output floor relative to the guide substrate.

An image forming apparatus comprises a printing module, a transporting mechanism and a sorting module. The printing module prints data on media in order. The transporting mechanism transports the media past the printing module. The sorting module is disposed downstream of the transporting mechanism, and comprises an output mechanism, a rack and a driving pinion. The output mechanism transports the media out in a first direction. The rack is connected to the output mechanism. The driving pinion meshing with the rack drives the rack and the output mechanism to reciprocate in a second direction, different from the first direction, to sort the media into stacks. Thus, the sorting function can be achieved without providing a larger space and moving a discharge tray, and this is advantageous to the miniaturization of the image forming apparatus.

A sheet processing apparatus includes a sheet processing unit that processes a sheet placed on a placing tray, a discharge roller that discharges the sheet processed on the placing tray to a stacking tray, a conveyance roller that discharges a sheet to the placing tray or conveys a subsequent sheet from upstream to downstream of the discharge roller and switchback-conveys the subsequent sheet upstream again, and a standby path (branch path) that keeps the sheet switched back by the conveyance roller on standby. The subsequent sheet is conveyed to a downstream side of the discharge roller by the conveyance roller and then returned to an upstream side again by switchback conveyance. During the switchback conveyance, the discharge roller nips and discharges the sheets on the placing tray to the stacking tray.

A paper delivery device includes a shift frame movable in a second direction perpendicular or substantially perpendicular to a first direction along which paper is delivered to outside, a driver that moves the shift frame in the second direction, a drive roller with a first outer peripheral surface extending in the second direction and supported by the shift frame such that the drive roller is rotatable about a first shaft parallel or substantially parallel to the second direction, a first driven roller with a second outer peripheral surface extending in the second direction and contactable with the first outer peripheral surface at a first contact position, the first driven roller supported by the shift frame such that the first driven roller is rotatable about a second shaft parallel or substantially parallel to the second direction following the rotation of the drive roller, the first driven roller being rotated in a state where the paper is nipped between the first outer peripheral surface and the second outer peripheral surface thus transporting the paper in the first direction, and a second driven roller with a third outer peripheral surface extending in the second direction and contactable with the first outer peripheral surface at a second contact position downstream of the first contact position in the first direction, the second driven roller being supported by the shift frame such that the second driven roller is rotated about a third shaft disposed parallel or substantially parallel to the second direction following the rotation of the drive roller, the second driven roller being rotated in a state where the paper which is nipped between the first outer peripheral surface and the second outer peripheral surface is nipped by the first outer peripheral surface and the third outer peripheral surface thus transporting the paper in the first direction.

An image forming apparatus includes plural medium transport paths that branch at a predetermined branching position and along which a medium is transported in a curved state; a switching member disposed at the branching position and including a guide surface that allows the medium to be transported along one of the medium transport paths, the switching member switching between the medium transport paths; an output unit that outputs the medium toward a stacking portion, on which the medium is to be stacked, while corrugating the medium; and a guide portion that guides the medium from the branching position toward the output unit in a region in which the medium is corrugated.

A present sheet post-processing device includes a first tray for stacking a sheet, a processing tray that temporarily stacks conveyed sheets until the number of the sheets reaches a predetermined number, and a discharge mechanism that discharges the sheets stacked on the processing tray onto the first tray. A sheet bundle forming unit divides, when forming a first sheet bundle on the first tray, sheets constituting the first sheet bundle into a plurality of sets and discharges the sheets a plurality of times for each set. At this time, a number of sheets included in a sheet set that constitutes a first sheet bundle and that is discharged at the first time is set smaller than a number of sheets included in a sheet set that constitutes a second sheet bundle and that is discharged at the first time.