Patent ID: 6912044

Claim:
A sheet post-processing device, comprising: a conveying roller which conveys a sheet; an intermediate stacking tray which has a pair of support members for respectively supporting edges of the sheet conveyed by said conveying roller in a direction intersecting with a sheet conveying direction, wherein each of the support members has a support portion for supporting one of the edges of the sheet and the support members are capable of moving toward and away from each other in a direction intersecting with the sheet conveying direction so that the sheet is pressed against one of the support members that serves as a reference by the other support member to be positioned; and a stacking tray which receives the sheet that is dropped through a gap created between inner edges, in the direction intersecting with the sheet conveying direction, of the support portions of the support members which are moved way from each other and are moved to respective retraction positions, wherein the gap is narrower on a downstream side in the sheet conveying direction than on an upstream side in the sheet conveying direction, when the support members are moved to the retraction positions respectively.