Patent ID: 6987525

Claim:
An image forming apparatus having a frame of a body and a paper storing unit mounted in the frame, comprising: a pickup unit picking up a paper sheet from a paper stack of the paper storing unit; a developing unit forming a toner image on the paper sheet; a fixing unit fixing the toner image into a visible image on the paper sheet; a paper conveyance guide having a first surface defining a first paper conveyance path that guides the paper sheet to the fixing unit through the developing unit, with the frame of the body; a paper discharging unit discharging the paper sheet after the visible image is fixed on the paper sheet; and a duplex printing unit conveying the paper sheet conveyed to the paper discharging unit back to the developing unit through the fixing unit to form another image on a non-printed side of the paper sheet, comprising: an auxiliary conveyance guide disposed on a second surface of the paper conveyance guide to define a second paper conveyance path with the second surface of the paper conveyance guide, the second paper conveyance path being formed to convey the paper sheet having a printed side and conveyed to the paper discharging unit to be fed back to the developing unit in a reversed posture, a reverse conveying roller assembly disposed between the second surface of the paper conveyance guide and the auxiliary conveyance guide to convey the paper sheet through the second paper conveyance path, and a paper conveying portion formed at a point where the first paper conveyance path and the second paper conveyance path meet, to convey the paper sheet picked up by the pickup unit and the paper sheet conveyed through the reverse roller assembly to the first paper conveyance path, wherein the paper conveyance guide comprises a plurality of protruding ribs formed on the first and second surfaces at predetermined intervals in a paper advancing direction to enable a paper conveyance to be performed while reducing a friction, and wherein the paper conveyance guide comprises one or more ground members secured on the first surface of the paper conveyance guide and a fixing portion fixing the ground members on the frame of the body to ground the paper sheet, and the fixing portion comprising one or more protrusions formed either on the ground members or on the paper conveyance guide, and one or more protrusion receiving holes formed either on the ground members or on the paper conveyance guide.