Optical sorting is a process of sorting a product using a photodetector (light sensor), camera, or the human eye.
In its simplest operation, a machine will simply see how much light is reflected off the object using a simple photodetector (such as a photoresistor) and accept or reject the item depending on how reflective it is (light or dark). More sophisticated systems use image processing to discriminate the colors of the object, often via a controlled spectrum of light, even beyond the visible spectrum into the IR and UV range. Shape detection is an evolving ability. The common method of removal is jets of compressed air, but others exist.
The term optical sorting also includes manual seeing and manipulating processes.
Famous quotes containing the word optical:
“It is said that a carpenter building a summer hotel here ... declared that one very clear day he picked out a ship coming into Portland Harbor and could distinctly see that its cargo was West Indian rum. A county historian avers that it was probably an optical delusion, the result of looking so often through a glass in common use in those days.”
—For the State of New Hampshire, U.S. public relief program (1935-1943)