POWDER AND GRAIN INSPECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To accurately discriminate whether or not a received light quantity of a light receiving means is within a proper light quantity range by improving an optical detecting part. SOLUTION: A detection point J where a powder and granular material group as the inspection object is sequentially conveyed and passed through is illuminated by diffused transmitted light and diffused reflected light which are light from illumination light sources 4A and 4B transmitted through diffuse transmission plates 18A and 18B and reflected by diffuse reflection plates 20A and 20B. Light of the same or substantially the same brightness as detected light from a normal substance in the powder and grain group is projected from a projection member 8 arranged on a back side portion of this detection point J toward the light receiving means 5. Light from the detection point J illuminated by the diffused light and a received light quantity of the projection light from the projection member 8 received by the light receiving means 5 are sampled at a set time interval. This sampled received light quantity is discriminated whether or not it is within the proper light quantity range in regard to the detected light from the normal substance.