Patent ID: 7206542

Claim:
A sheet post-process apparatus, the apparatus comprising: a waiting tray which temporarily retains a transported sheet in a waiting mode, and releases a retention to drop the sheet; a processing tray which bundles sheets dropped from the waiting tray to carry out predetermined processing, and ejects the bundle of sheets; and a storage tray which holds the bundle of sheets processed and ejected on the processing tray, wherein the waiting tray comprises: left and right lower face support members which support left and right lower faces in a sheet transport direction during the retention in the waiting mode, wherein the left and right lower face support members are positioned to support a proximal end side and a distal end side of the sheet in the waiting mode, and release a support of the left and right lower faces during release of the retention, a width of an opening portion formed between both of the members being widely formed at the distal end side compared with the proximal end side in a transport direction of the sheet transported to the waiting tray; drive means for opening the left and right lower face support members to widen the width of the opening portion; sensor means for sensing the sheet transported to the waiting tray; and control means operating in the waiting mode and a non-waiting mode, the control means drives the drive means based on a sense signal of the sensor means, and the control means controls the drive means so that both of the support members are opened to an extent such that the width of the opening portion is narrower than a sheet width at the proximal end side in the transport direction of the sheet and is wider than the sheet width at the distal end side thereof, wherein the left and right lower face support members are positioned to support only the proximal end side of the sheet in the non-waiting mode, so that the sheet is dropped from the sheet distal end to the processing tray without being retained in the waiting mode.