Patent ID: 8770570

Claim:
A sheet processing device comprising: a stacking unit configured to stack thereon one or more conveyed sheets; a staple unit configured to staple a bundle of sheets stacked on the stacking unit; a moving unit configured to move the staple unit to a staple position; and a projecting and retrieving unit configured to project and retrieve the stacking unit in a space overlapped with a motion space for the staple unit to move therein, wherein: the stacking unit includes a fixed tray and a movable tray, the projecting and retrieving unit projects and retrieves the movable tray along the fixed tray, the projecting and retrieving unit retrieves the movable tray from the motion space, in order to move the staple unit by the moving unit, and the moving unit as well as the projecting and retrieving unit are driven by the same drive source.