Abstract: An infrared light generator directs a flashing band of light across a conveyor belt carrying randomly spaced materials having differing properties. The frequency of the flashing band sequentially alternates between two infrared frequencies chosen for their peculiar reflectivity characteristics. Infrared light sensitive cells detect energy reflected from the passing materials as they are exposed to the infrared light. Comparator circuitry examines the detected information, determining the size and material nature of the passing pieces. Powered paddles act at the direction of the comparator, physically separating variously sized inorganic from organic materials, or ripe from unripe comestibles, to cite examples.

Abstract: A produce sorting unit that is a separate item of commerce intended for mounting on an existing produce harvester that has a conveyor for conveying produce to be sorted or graded. The unit comprises a frame that is adapted to be lifted onto the existing harvester and installed without requiring major alterations or modifications to the harvester. The frame supports a pair of produce elevating conveyor belts that extend outwardly from the frame and downwardly to the harvester conveyor to pick up produce therefrom. A horizontal conveyor belt supported on the frame receives produce from the elevating conveyor belts and carries it to an inspection location. The unit also includes a rejected produce conveyor belt underlying and extending transversely to the horizontal conveyor belt. Optic-electronic sorting means secured to the frame is responsive to light received from the produce as it is discharged from the horizontal conveyor at the inspection location.