Sheet treating apparatus and image forming apparatus having the same

摘要

A sheet treating apparatus includes a tray liftable and lowerable while sheets are stacked on the tray. A sheet pressing member is movable between a pressing position in which the sheets on the tray are pressed by the sheet pressing member and a retracted position. A sheet pressing member driving device retracts the sheet pressing member when the tray is lowered and for moving the sheet pressing member to the pressing position when the tray is lifted. A detecting device detects a height position of the sheets on the tray to stop lifting the tray.