Machine vision system is through machine vision products (that is, image intake device, divided into CMOS and CCD two) will be ingestion target into image signals, transmitted to the special image processing system, get the shape information of the target, according to the pixel distribution and brightness, color and other information, into digital signals; The image system performs various operations on these signals to extract the characteristics of the target, and then controls the action of the equipment on site according to the discriminant results. The manufacture of the machine vision system has been used in various industries, involving hardware, mobile phone, 3 c electronics, auto parts, medical equipment, semiconductor chip, the new energy industry, as well as intelligent automation, logistics and other fields, greatly improve the product quality, reduce production cost, to enhance human essence demand for industrial products. hardware Hardware in the production process, inevitably will produce some appearance defects, such as lack of material, cracks, burrs, scratches, bruisesetc., these or large or small defects sometimes not only affect the appearance of beautiful, but also may affect the normal performance of the whole equipment and safe operation. Factory by adopting hardware detection based on machine vision inspection technology screening machine, a full range of