Dynamic sheet count predictor

Claim 1

In a sheet feeding and imaging system, with a sheet stacking and feeding tray in which a set of document sheets may be stacked to be sequentially fed from said tray by a sheet feeder for image processing, and sheet counting means for providing a count of the number of document sheets fed from said tray, and a set stack height estimating means for providing plural distinct discrete stack height control signals responsive to the height of said set of sheets in said tray, and control means electrically connecting with said set stack height estimating means for providing preset estimates corresponding to respective said discrete estimated stack height control signals of the number of said document sheets in said set; the improvement wherein said operation of said set stack height estimating means and said sheet counting means is dynamically monitored and compared by said control means for determining a specific said count of the number of said document sheets which have been fed from said tray prior to a change occurring in said distinct discrete estimated stack height control signals during at least the initial feeding of said document sheets, and said preset estimate from the respective said discrete estimated stack height control signal of the number of said document sheets in said set is modified in accordance with said specific count, and wherein said sheet feeding system is a recirculating document handler and said set of document sheets are a set of documents being plurally recirculated in a document circulation path for imaging and returned in said document circulation path back to said same tray to be restacked in said tray, and said set stack height estimating means is an electromechanical system in which a finger is set on top of said set of document sheets as they are initially loaded into said tray, and said document sheets are fed out from under said finger by said sheet feeder, and the position of said finger provides said discrete stack height control signals.