Sheet post-processing apparatus and image formation system provided with the apparatus

摘要

To provide a sheet post-processing apparatus enabling a sheet to be aligned in a predetermined collection position irrespective of the basis weight of the sheet and image formation surface in dropping and collecting the sheet onto a tray from a sheet discharge outlet, the apparatus has a tray for collecting a sheet from the sheet discharge outlet, and a sheet discharge rotating body for transferring the sheet that is carried out to the tray toward a sheet end regulation member, and is configured to be able to adjust the timing of shifting the sheet discharge rotating body to an operation position engaging in the sheet from a withdrawal position above the tray corresponding to image formation conditions of the sheet.