RESTACK JAM DETECTION
Original Publication Date: 1982-Aug-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
As shown in the three accompanying figures, in a sheet handling apparatus in which flimsy sheets are stacked on top of a stack thereof, specifically in a recirculating automatic document handler for a copier, there is disclosed an improved mis-stacking detection system comprising optical sensing means defining a single sheet interruptable optical sensing path or beam extending transversely just above the sheet stack in a position to be interrupted by variously mis-stacked (non-planar) sheets extending above the stack, which optical sensing means is connected via a time delay system to a sheet mis-stacking indicator so that activation of the mis-stacking indicator is prevented for brief interruptions of the optical sensing path corresponding to normal sheet stacking, but is activated by an interruption of the optical sensing path which continues for a preset time period (longer than the time delay) indicative of the presence of a mis-stacked sheet. The optical sensing path extends over the full actual stack support area from one side to the other and from adjacent one end thereof towards the opposite end thereof, but automatically accommodates the resetting of the sheet restacking edge guides for different sheet sizes by reflecting the light beam back to an integral light sensor from a reflective surface on the movable edge guide.