Abstract: A method and apparatus for detecting foreign matter in a particulate material stream, particularly tobacco, including an optical scanner, in combination with a camera system with beam splitter and filters, and a computer to process signals from the camera to determine whether foreign matter is present. If foreign matter is detected, a diverter deviates the flow of the contaminated material onto a discharge conveyor.

Abstract: A sensor for creating images containing range depth information is disclosed. The sensor comprises a gated energy transmitter used to "illuminate" the object to be imaged, a gated integrating imaging energy receiver to produce "raw" images, a processor system to combine the raw images from the receiver to produce a output image, and a timing system to control the gate timing of the transmitter and gate timing of the receiver. In operation, two raw images are created with differing time relationships between the transmitter gating, receiver gating and integrated energy readout. One raw image is a reference image containing no range information while the second image contains range information along with unwanted information such as reflectivity variations. These raw images are processed to produce a final output image in which the unwanted information is mainly cancelled producing an output "range" image. This output image is a one or two dimensional array of data.