Patent ID: 7686296

Claim:
A sheet stacking device comprising: an evacuation section for transporting and ejecting sheets; a sheet exit tray for stacking the ejected sheets; an arm supporting member; and a sheet presser arm including a supported end immovably, substantially integrally and fixedly supported by and immovably, substantially integrally and fixedly attached to said arm supporting member at one end, a free end at the other end which is capable of pressing the sheets stacked on the sheet exit tray directly or via a contact member attached to the free end, and a flexure portion having flexibility extending between the immovably, substantially integrally and fixedly supported and immovably, substantially integrally and fixedly attached end and the free end, wherein the arm applies via the flexibility of the flexure portion, a pressing force to sheets stacked on the sheet exit tray and a repulsive force to each ejected sheet when a front end of the ejected sheet strikes against the arm, and wherein the arm has a bend between the immovably, substantially integrally and fixedly supported and immovably, substantially integrally and fixedly attached end and the free end, and the shape of the arm is determined in view of an attachment angle of the immovably, substantially integrally and fixedly supported and immovably, substantially integrally and fixedly attached end of the arm with respect to a horizontal direction, the length of the flexure portion between the immovably, substantially integrally and fixedly supported and immovably, substantially integrally and fixedly attached end and the bend, and the length of the flexure portion between the bend and the free end.