Design And Implementation Of DSP Based Pellicle Defect Online Inspection System

At present,the defect inspection of the pellicle is basically done by human vision in China.The quality of the pellicle is judged by subjective sense.There will be some questions such as low speed,low efficiency, high leave out rate and so on.With the development of computer and digital image processing technologies,it is possible to develop an automation on-line inspection system based on machine vision.The on-line inspection is widely applied in modern industrial automation production.In this thesis,the software and hardware design of the on-line inspection system based on DSP is dissertated in details.In the design of hardware,without frame grabber,the input and building up of video signals in double CCD cameras by transition circuit for CCD high speed digital signal,real-time data memory circuit,the produce circuit of synchronous frame signal and DVAL signal,the selector of multiway signal;Because the velocity of Pellicle change constantly,CCD's default parameters cannot be fit for the reality.The communication between DSP and CCD by MCBSP port in C6416 is realized,in order to dynamically set the CCD parameters.The sampling frequency of CCD and the time of exposure is controled by measuring the line velocity of dynamic Pellicle with increment coder and send this result to DSP,and DSP computing the real-time sample frequency of CCD.As to software,based on the system characteristic of data mess and high real time capability,the software design mode of real time and hypo-real-time combination is adopted,and the arithmetics such as median filter,image fusion,gray matching and so on are used.The research finally accomplishes primary design of on-line surface inspection system for the pellicle.After several tests,the real-time capability and precision of the system can satisfy the demand of real production.