DUAL - a double feed detector for flat sorting machines

摘要

Every day, vast quantities of letters, forms, cheques, advertising, etc... are processed on production lines which have become more and more automated. The French Post Office has successfully automated the sorting of letters, and hundreds of millions of letters are sorted automatically every year.rnHowever, flats (postal items ranging in size from C5 to 260×380 mm) are much more difficult to process automatically : the form of such objects varies tremendously, not only in size but also in thickness, rigidity and type of envelope material (paper or plastic). As a result, de-stacking or separating them is a particularly tricky operation.rnBecause it is difficult to improve the destacking process at the sorter input, SRTP has concentrated on a method of detecting unseparated objects and rejecting them. In this way, there is little risk of objects being dispatched in the wrong direction, which is a high cost factor for La Poste.