Patent ID: 8752827

Claim:
A medium stacking apparatus comprising: a stacking frame forming a stacking space in which media are stacked, and comprising a medium inlet; and a damper colliding with the medium introduced through the medium inlet, and absorbing a shock from the medium, wherein the damper comprises one or more damping ribs that extend in a stacking direction of the media and are elastically deformed by a collision with the medium, a damper plate provided at a rear side of the one or more damping ribs to support the one or more damping ribs, and a plurality of guide protrusions disposed on a surface of the damper plate, wherein the damper plate facing the medium inlet is elastically attached to a surface of the stacking frame by an elastic spring, wherein each of the one or more damping ribs comprises a first rib fixed to the damper plate, a plurality of connecting ribs connected to the first rib and vertically spaced apart from each other, and a second rib connected to the connecting ribs, wherein the plurality of guide protrusions are disposed vertically spaced apart from each other such that the medium is inhibited from downward sliding, and wherein the first rib, the plurality of connecting ribs and the second rib are integrally formed with each other.