Abstract: Disclosed is apparatus for sorting objects, e.g. tomatoes, according to both size and color. A preferred embodiment can sort the objects into fourteen size/color categories and yet requires only two photodetectors. The objects travel on a conveyor belt past a sensing station having a light source to illuminate an object and a pair of phototransistors for receiving light reflected from the object in two different color bands, e.g. red and green. The phototransistors produce a pair of output electrical signals. An analog divider forms a ratio of the electrical signals and the peak value is stored and compared with preset limits to produce a color category signal. A size category signal is derived on the basis of the time duration of the signal produced by the summation of the phototransistors' signals.
Type:
Grant
Filed:
June 13, 1977
Date of Patent:
January 2, 1979
Assignee:
Joerg Walter VON Beckmann
Inventors:
Joerg W. von Beckmann, Norman R. Bulley