Sorter and image forming apparatus

摘要

A sheet sorting apparatus includes a plurality of trays for accommodating sheets; helical cam device, engageable with a cam follower for moving the plurality of trays; cam driving device for driving the helical cam device; sheet set processing device movable between a processing position and a retracted position where the processing device does not interfere with the plurality of trays; reversible driving device for advancing or retracting the sheet set processing device; and controlling device for controlling the driving device; wherein a cam surface of the helical cam is constituted of substantially horizontal portions and slanted portions; and the cam driving device and the driving device are controlled by the controlling device, in such a manner that the processing device is advanced to, or retracted from, the tray, within a time duration in which the cam driving device is operated, and the cam follower is being engaged with the horizontal portions of the cam device. <IMAGE>