Multiples detect apparatus and method

Abstract

The invention provides an apparatus and method for detecting overlapped mail pieces when sorting batches of flat mail pieces as the pieces are conveyed on their narrow sides, whereby the sorted mail pieces are moved successively standing on their narrow sides in a longitudinal direction along a bed or path. Positioned below the path is an electronic line camera arranged with its longitudinal axis perpendicular to the feed direction of the sorted mail pieces that scans the lower narrow edges of the mail pieces through a gap in the bed. In one aspect, two sources of light, such as light emitting diodes, are positioned laterally from the line camera diagonally illuminate the mail pieces from below as the mail pieces pass over a window in the path so that the edges of the scanned narrow sides are emphasized by shadowing. Features of the scanned images are transmitted to an evaluation means that utilizes statistical analyses and compared with models of known physical mail piece configurations determined off-line to determine the model that most agrees with the analysis of the scanned image data. In one aspect the evaluation means comprises a microprocessor that is preprogrammed to compare and statistically analyze the captured image data with reference to standard image data and determine the probability that the scanned image data represents over lapping mail pieces, in which case the microprocessor generates a signal that triggers corrective action.