Sheet handling unit after image formation

FIG. 1 is a perspective view showing an external appearance of an image forming apparatus (in this embodiment, copying machine) incorporating a sheet handling unit (or post processing unit) embodying this invention. To clarify the directional relationship of various parts to be described later with reference to the drawings, X-, Y-, and Z-coordinates are shown in the drawings when needed. The arrow of +X direction represents frontal direction: -X direction represents rearward direction; +Y direction represents rightward direction; -Y direction represents leftward direction; +Z direction represents upward direction; and -Z direction represents downward direction of the copying machine.

[Schematic arrangement of copying machine]

As shown in FIG. 1, the copying machine comprises a main body 1, a paper storage unit 2 arranged on the right side of the main body 1 (i.e., on the +Y side), and a sheet handling unit 3, which includes a sorter, arranged on the left side of the main body 1 (ie., on