Patent ID: 8457543

Claim:
An image forming apparatus comprising: an image forming unit to form an image on a sheet of recording media; an image reading unit to read image data of an original document, disposed above the image forming unit; a sheet discharge space defined by multiple inner walls of a main body of the image forming apparatus including a first inner side wall and a second inner side wall, the sheet discharge space disposed between the image reading unit and the image forming unit; a discharge port located on the first inner side wall of the main body of the image forming apparatus, the discharge port being a slot having a width at least equal to a width of the sheet of recording media discharged into the sheet discharge space through the discharge port; and a positioning member configured to position and detachably mount one of a plurality of auxiliary units adjacent to the discharge port in the sheet discharge space defined by multiple inner walls of the main body, the positioning member including, a plate having first and second surfaces and a pass-through port therebetween, the pass-through port being a slot having a width at least equal to the width of the sheet of recording media, the first surface including an engagement part configured to removably engage the one of the plurality of auxiliary units as an engaged auxiliary unit, the plurality of auxiliary units each having a receiving port, the receiving ports each being a slot having a width at least equal to the width of the sheet of recording media, and a positioning portion mountable in the sheet discharge space to the second inner side wall of the main body such that the second surface of the plate overlaps with the first inner side wall of the main body to align the pass-through port on the second surface with the discharge port and to align the pass-through port on the first surface with the receiving port of the engaged auxiliary unit such that the sheet of recording media can pass from the discharge port to the receiving port through the pass-through port to provide the sheet discharged through the discharge port to the engaged auxiliary unit.