Patent ID: 7419151

Claim:
A sheet processing apparatus, comprising: a first roller pair rotatably held and driven for conveying a sheet received from an external apparatus; a second roller pair rotatably held and driven for conveying the sheet conveyed from the first roller pair; a guide channel between the first roller pair and the second roller pair through which each sheet passes, the guide channel formed by an upper guide plate and forming an open area below the upper guide plate; a jogging tray on which sheets conveyed from the second roller pair via the guide channel are stacked and jogged; a binding device for binding a stack of sheets received and jogged by the jogging tray; and a controller for controlling the second roller pair so that during a standby operation, leading edge ends of sheets received from the external apparatus and conveyed by the first roller pair one after another via the guide channel are pinched by the second roller pair while being overlapped and stacked one upon another with leading edges thereof shifted stepwise one after another and so that trailing edge ends of the stacked sheets are discharged into the open area while the stacked sheets are held by the second roller pair to be further conveyed by the second roller pair to the jogging tray, wherein the guide channel between the first roller pair and the second roller pair through which each sheet passes is formed by the upper guide plate and a lower pivotally movable guide plate, the lower pivotally movable guide plate capable of pivoting between a first position adjacent the upper guide plate to form the guide channel and a second position not adjacent the upper guide plate to form an open area below the upper guide plate and wherein the controller controls the second roller pair and the pivotally movable guide plate so that during a standby operation, leading edge ends of sheets received from the external apparatus and conveyed by the first roller pair one after another via the guide channel are pinched by the second roller pair while being overlapped and stacked one upon another with leading edges thereof shifted stepwise one after another and moves the pivotally movable guide plate to the second position not adjacent the upper guide plate to form the open area below the upper guide plate so that trailing edge ends of the stacked sheets are discharged into the open area while the stacked sheets are held by the second roller pair to be further conveyed by the second roller pair to the jogging tray.