Automated inspection system

Abstract

An automated inspection station comprises a pair of rotating rollers for supporting a collected group of pellets. A pusher drops in behind the group to urge the entire group forward. The rotating rollers cause the entire group of pellets to spin in unison as the pellets pass through an optical inspection station. The optical inspection station comprises a light source, diverging and collimating lenses to illuminate each rotating pellet in turn. Signals are generated by at least two arrays of photodiodes in response to light reflected from the surface of the pellets. Circuitry normalizes the signals of the respective diodes for variations unrelated to pellet surface features. The signals are analyzed to ascertain conformance of each pellet to length, cylindricality diameter and surface reflectivity requirements. A pellet sorter diverts unacceptable pellets from the path, while the acceptable pellets are transported to a collection station. Additional circuitry generates known timing pulses which control the axial speed of the pellets advancing past the inspection station, as well as for synchronizing and correlating the collected data with the respective advancing pellets. The number of threshold changes and their location on the pellet help determine conformance to the above criteria.