Method and Device for Sorting Products

The invention concerns a method and apparatus for sorting a stream of products by scanning this stream of products with a bundle of concentrated light and analyzing the light originating from the scanned products and a background element, wherein this background element is chosen such that the corresponding detected light signal differs from the light signals originating from the products to be sorted in at least one parameter and wherein one or more control signals are generated by shifting the background level of the observed light signals to a signal level chosen such that, in the thus obtained signal, the signal level of the signal of a scanned product to be accepted distinguishes itself from the signal level of the signal of a scanned product to be rejected.