Plate counter

摘要

A carriage having (1) an infrared energy ray emitter and detector and (2) an encoder is displaced over a side of stacked glass sheets to sense density of reflected energy rays as a function of carriage position on the stack. The sensed density of reflected infrared energy rays from the edges of the outermost sheets and the interface between adjacent sheets is less than the sensed density of the reflected rays from the sides of the sheets. The output signal of the encoder and of the detector is acted on to determine the number of sheets in the stack.