Optimized design of an AOI illuminator

This paper investigates an illuminator for automatic optical inspection (AOI) machine. The structure of the illuminator was determined first, the illuminator composed three light emitting diode (LED) array sources; the color and the radiation angle of each LED array source are different. Then, the irradiation model of the illuminator was established according to the structure. Finally, the dimensions of the illuminator were optimized based on the irradiation model. Several experimental results show that the illuminator can improve the stability of the AOI.