According to one embodiment, a sheet post-processing device includes a first tray to receive sheets from an image forming unit, a second tray to receive sheets from the first tray, and a third tray to receive sheets from the second tray. The third tray is movable relative to the second tray. A bundle claw is configured to move sheets in a first direction from the second tray to the third tray. A controller is configured to move the third tray relative to the second tray according to the sheets on the second tray. Depending on various characteristics of the sheets on the second tray or the presence of sheets already on the third tray, the position of the third tray may be changed to reduce possible misalignments of sheets in the transfer from the second to third tray.

A paper sorting device includes: a stacking conveyor that receives continuously fed cut sheets to stack the cut sheets by sorting unit and that continuously conveys stacked cut sheets downstream on a unit-by-unit basis; and a stacker section arranged downstream of the stacking conveyor, capable of continuously stacking the stacked cut sheets conveyed from the stacking conveyor, at different positions on a placement surface.

According to one embodiment, a sheet post-processing device includes a first tray to receive sheets from an image forming unit, a second tray to receive sheets from the first tray, and a third tray to receive sheets from the second tray. The third tray is movable relative to the second tray. A bundle claw is configured to move sheets in a first direction from the second tray to the third tray. A controller is configured to move the third tray relative to the second tray according to the sheets on the second tray. Depending on various characteristics of the sheets on the second tray or the presence of sheets already on the third tray, the position of the third tray may be changed to reduce possible misalignments of sheets in the transfer from the second to third tray.

A sheet processing apparatus performs a binding discharge process and a sorting discharge process. In the sorting discharge process, a second operation is repeatedly performed to form an unbound first sheet bundle on the stacking portion, and a third operation is repeatedly performed to form an unbound second sheet bundle on the stacking portion. In the second operation, a sheet conveyed in a first conveyance direction is nipped by a pair of alignment plates without conveying the sheet in a second conveyance direction, and a shift operation of moving a position of the sheet in a shift direction is performed. Then the sheet is discharged to a shift position on the stacking portion. In the third operation, the sheet is discharged to a position displaced from the shift position on the stacking portion without conveying the sheet in the second conveyance direction.