Patent ID: 7203454

Claim:
A sheet post-process apparatus, the apparatus comprising: a waiting tray which temporarily retains a transported sheet in a waiting mode and releases the retention to drop the sheet; a processing tray which bundles the sheets dropped from the waiting tray to carry out predetermined processing and ejects the sheet; 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 retention in a waiting mode and release the support on the left and right lower faces during release of the retention; a distal end lower face support member which supports a distal end lower face of the sheet transported to the waiting tray; a distal end upper face retainer member which retains a distal end upper face of the sheet transported to the waiting tray; sensor means for sensing that a sheet has been held on the waiting tray; and driver means for, based on a sense signal of the sensor means, moving the distal end upper face retainer member to a location for retaining the distal end upper face of the sheet transported to the waiting tray.