Abstract: In a bichromatic sorting machine, a polygon pattern of trip level boundaries is established for a master channel programmable memory that is representative of orthogonally plotting detected products in each of two reflectivity spectral bands. The rate of products passing through the master channel that is rejected as being non-acceptable by producing a reflectivity value outside of the polygon pattern compared to total products sorted is used as the basis for normalizing all channel results. When the actual rate in the master channel varies from the desired rate, the boundaries of its polygon are concentrically adjusted back to the desired rate, thereby also adjusting the similar polygon patterns for each of the other or slave channels. Multiple machines can also be normalized to the same rate in similar fashion. The master channel or the master machine can be selectable, a concept that is also applicable to monochromatic sorting machines, as well.

Abstract: A method and apparatus are disclosed for detecting and ejecting articles of different weights in a product and article stream, by varying the dwell and delay time in accordance with the color classification of the products and articles being sorted. The ejector dwell and delay times are determined by the weight of the products and articles, which can be identified by the percentage reflectivity of color wavelengths of interest.

Abstract: Apparatus and method for measuring the reflectivity of a product for use in optical sorting machines that is insensitive to product size and orientation. The percentage reflectivity of a product passing a background is corrected by a frame fill factor, which is representative of the percentage of the viewing frame occupied by the product being sorted.