Pcb Appearance Detector Of Cmos Image Acquisition Based On Fpga

The PCB visual inspection is a kind of Automatic Optical Instrument (AOI) which can find the surface defect that include oil pollution, copper leakage, scratch, character error and others on PCB, and it is fast, stable and reliable. It improves the quality of PCB manufactures’product, reduces the labor intensity of inspection staffs, and also improves their working efficiency. It is an ideal commodity inspection equipment which for PCB manufacturers.Now, the imaging acquisition device of PCB visual inspections is from abroad because of the technology blockade. There is no high resolution and definition products in domestic markets, however, only low-end, even eliminated products, which is for foreign countries, with a high price are sold. In view of this phenomenon, a kind of CMOS imaging acquisition system based on FPGA is proposed in this dissertation, which means the imaging camera can be made independently instead of buying from abroad. This platform can be upgraded without hardware circuit being changed.In this dissertation, a hardware platform of image acquisition and transmission is introduced, and each part of the platform, including the CMOS imaging sensor’s configuration module, the data receiving module, FPGA control module, the memory module, and the USB interface module, are demonstrated and their chosen standard is given. On the software design, a two-wire serial bus used to config the CMOS sensor, valid data chosen module, and memory control module are discussed. And the SOPC technology is used.To our knowledge, this dissertation is the first report of making a image acquisition platform with the CMOS imaging sensors based on FPGA, and using it to the PCB visual inspection system.After repeated experiments, and considering the final results, this system is proved to be simple structure, high-speed, and well scalability. And this system is of good value for application.