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Online Inspection System For Black-white Film Defects

Posted on:2008-11-25Degree:MasterType:Thesis
Country:ChinaCandidate:W L LiuFull Text:PDF
GTID:2178360245491855Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
With the spreading of digital camera and digital video camera, film, as an traditional media for information store, has confronted a great impact, and the global market of film products has shrinked remarkably. But as a mature and low-cost imaging technology, imaging on black-white film has been widely used in the market of developing countries, some special fields and by the fans of photography, and black-white film still has static and sufficient requirement. During the progress of black-white film production, some defects appear randomly because of the technical limitation and human factors. The previous methods of defects'inspection are not able to detect all the defects in the real time, so those methods can not ensure the quality of film. In this dissertation, a newly-developed online automatic inspection system for black-white film defects is introduced. It can judge and detect the defects automatically, and the system enhances the quality standard of the film.In this system, the images of the film which are formed through the NIR light are obtained by CCD camera and transferred to the processing computer. By means of arithmetic about smooth filtering, edge detection and aggregation judgment, when the speed of film collecting machine is set between 20~70m/min, the system can inspect the typical kinds of black-white film defects effectively meanwhile ignore the minor defects that do not affect the film's application. Cooperating with the PLC of collecting machine, the system also realizes the function of auto stop and rewinding the film to the point where the defects are detected. The system also has complete assistant functions for testing and demarcating the inspection standard, which ensures the consistency of inspection.Experimental result shows that this system works stably, thus it can meet the need of production properly. The resolving power of the system is 70μm. The system has already be applied in the mass production, and it improves the quality of black-white film effectively thus raises the competition power of the products.
Keywords/Search Tags:defects inspection, image processing, edge detection, black-white film, online inspection
PDF Full Text Request
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