Operation

A small bright spot, focused on the product, is scanned across the product at a high rate of speed (sometimes as high as Mach 40, 40 times the speed of sound). This "scanning" action is so fast that the entire product is bathed in laser light. The laser system performs the same functions as a human eye. In both cases, light is captured, converted into electrical signals, and the signals are transmitted to a processor for recognition and classification.

If defects occur, the light energy changes (becomes brighter, dimmer, changes direction, coherence, etc.) and these changes are captured in the electrical signals.