Patent ID: 7768643

Claim:
An apparatus for classifying articles comprising, transport means connected to a frame for directing articles having a transport direction, such that a product stream is created, at least an emitter section connected to the frame, the emitter section comprising at least one radiation source of electromagnetic radiation having at least a first wavelength and an initial polarization (P 0 ), wherein radiation from the radiation source is directed towards a scanning zone, wherein the articles move through the scanning zone, at least a detection section connected to the frame for detecting at least a portion of radiation reflected by articles in the scanning zone, the detection section comprising at least a first detection means for converting radiant power of the portion of reflected radiation having a first polarization state (P 1 ) into a first electrical signal (E 1 ), at least a second detection means for converting radiant power of the portion of reflected radiation having a second different polarization state (P 2 ) into a second electrical signal (E 2 ), and a third detection means for converting radiant power of the portion of reflected radiation into a third electrical signal (I), control circuitry in operable communication with the detection section for receiving the electrical signals, wherein the control circuitry comprises decision means for generating a selection signal (S 1 ) based on the received electrical signals and threshold values from a memory, and selection means for separating products from the product stream arranged downstream from the detection section, wherein the selection means are actuated to separate an article from the product stream according to the received selection signal (S 1 ) from the control circuitry.