Sheet post-processing devices

A sheet post-processing device having a storing tray for storing a sheet and a process tray having a sheet placing surface for post-processing the sheet, said sheet post-processing device including a first mode for guiding the sheet from an image forming device to the storing tray and a second mode for guiding the sheet from the image forming device to the process tray, and guiding the sheet to the storing tray after predetermined post-processing is operated,

• wherein said sheet post-processing device further comprises guide means for guiding the sheet from the image forming device to guide the sheet to the storing tray at a position spaced from the sheet placing surface of the process tray and to reach the storing tray, said guide means being transferred to a position for guiding the sheet to the storing tray in case of the first mode, said guide means being transferred to a position to guide the sheet to be placed on the sheet placing surface of the process tray in case of the second mode.