Abstract: An improved stacker for an automatic document sorter is described. The stacker is vertical and receives documents at the top thereof and expels them at the bottom. The stacker includes a paddle normally disposed at the top for receiving the first document and subsequent documents stacked thereon. As documents enter the stacker, the paddle drops due to the action of a timing belt and sensor arrangement until it reaches the bottom. At the bottom, a horizontally directed timing belt withdraws the paddle from the stacker and the paddle is then returned by reverse action to the top of the stacker and reinserted thereinto for receiving the next stack of documents. Both timing belts are independently driven by motors.

Abstract: A singulator of the friction belt type capable of synchronous or asynchronous modes of operation is described. The singulator includes a buffer assembly for accepting a shingled stream of documents, a feeder pinch belt for extracting the first document from the buffer and a scanner for scanning the document as it passes through the feeder into an accelerator which is also a pinch belt. The accelerator accelerates the document to a constant speed leaving the singulator. A control means is provided which operates coupled to the feeder drive and the scanner so that the next upstream document is extracted a predetermine time after the first document leaves the accelerator.

Abstract: A machine for sorting documents and, in particular, for carrier sequence bar code sorting of mail has been described. The device uses three passes and 11 vertically disposed top fed stackers. The stackers also have a delivery system from the bottom thereof so that mail selectively dispensed from the bottom of each individual stacker proceeds through a buffer singulator, leveler, and wide area bar code reader which in turn signals the computer so that as the mail piece is transported through a top transport, it will be gated into the proper stacker in the proper sequence. The machine also may be adapted to an overflow situation wherein mail overflowing one stacker is diverted to an overflow stacker for recycling and the mail to be sorted is assigned in predetermined quantities to different stackers to minimize the possibility of overflow.

Abstract: An envelope reflectance meter for evaluating the contrast between ink on a pre-printed envelope and the envelope itself and for calculating and displaying the print contrast ratio and the print reflectance difference is described. The device includes a portable housing having internally a pair of light sources which generate a reflected image of the envelope. The image passes through a lens, is reflected from a mirror, and is then displayed on a viewplate. An aperture is provided in the viewplate which passes a beam of light. The beam of light is then split and the two beams resulting analyzed for red content and green content. The analog signal produced is then converted to digital and the print contrast ratio and print reflectance difference calculated. A display is provided within the housing adjacent the viewplate whereby selectively the values for red light and for green light and comparisons between the readings for ink and the readings for the envelope are selectively displayed for an operator.