Array Automated Optical Inspection Method Research

AOI is short for Automated Optical Inspection,using high-performance digital camera to take images, while the images are formed by the pixels.This system analysis the actual image ,compared with standard imaging features, after, you can determine this is right or wrong.This process is known as the pixel grid processing ,belong the appearance test approach.. With the development of the industry techniques, AOI is flourished and progressing quickly. Facing the challenge, which from the new part specification, another AOI system architecture is brought forward, that is Array, arranged Image System.For the image module, In order to meet the hardware-based series inside and the memory size limit, we make the image values method .This detection method is using several image characteristic values as the image itself , then use they to test.For the PC itself, we make the method of image compare, one of a template matching method . It is a method that calculate degree of similitude between the inspect image and the template image(standard image) .Before that we can use zoom operation and fuzzy operaton as pretreatement.For the text on components and circuit board. We make the character text projection inspect method . After project character, we calculate the degree of difference between text projection cruve and the standard projection cruve. Before that we use corrosion expansion operation and image enhance operation as pretreatement.These methods applied to various parts of AOI array and can be tested in their respective areas of work in order to achieve the purpose of all inspection.