Research On Polarization Detection Technology For Scratch Defects On Computer Surface

The rapid development of computer products has resulted in a growing variety of application fields,although scratch defects on the surface might occur for a variety of reasons during the manufacturing and processing operations.As a result,the problem of scratch defects is gaining more and more attention,and research into scratch defect detecting technologies is critical.Traditional manual inspection technology relies mostly on the human eye to detect scratch defects;however,the detection standard is not uniform,the results are subjective,and the detection efficiency is low.The detection efficiency of image vision defect detection technology is high,but there are some drawbacks,such as the lack of quantitative indicators to assess the severity of defects,scratch defects detected by the image of visible light intensity image,and the detection process' inability to effectively obtain more physical information.The polarization image can obtain the multidimensional information of the target object and extend the physical information of the target surface from three to seven dimensions.For the surface defects that cannot be effectively detected by the visible intensity image,they can be detected by using the polarization image.During the scratching process on the computer surface,the surface roughness will change,resulting in a change in the degree of polarization of the polarized light in the outgoing light wave after the incident light wave acts on the target surface.Therefore,incorporating polarization imaging detection into the scratch defect identification process can help to reduce the impact of complicated background elements,increase image contrast,and get more physical information about the target.The research into how the polarization degree of polarized light varies in light waves operating on the surface of various scratch defect degrees,the entire Stokes polarization information parametric description,and the scratch defect severity study's quantitative assessment index.The three works described in this article revolve around the polarization detecting technology for scratch problems on computer surfaces.(1)The polarization properties and expression methods of optical waves and the mechanism of polarization detection are studied.The polarization properties of light waves,the four expressions of polarized light,and the principle of full Stokes polarization imaging are introduced.The main influencing factors in the process of polarization detection are studied,and the effect of the change of surface roughness on polarization detection is analyzed.To build a platform for measuring the roughness value of scratch defects on computer surfaces,and to investigate the correspondence between the number of different scratches on computer surfaces and the surface roughness value,and the measurement results show that the surface roughness value increases as the number of surface scratches increases.(2)The polarization characteristics of scratch defects on computer surfaces were studied.The comparison analysis between visible intensity images and polarized images is conducted to verify that the polarized images can effectively obtain more physical information of the target.In response to the lack of quantitative evaluation indexes,the full Stokes polarization information parametric images were obtained according to the different degrees of polarization of polarized light in the incident light waves acting on different roughness surfaces,and it was found that the higher the severity of scratch defects characterized by the number of scratches,the smaller the values of S1 and S3 parametric polarization characteristics in the full Stokes parametric values,and the larger the values of S2 parametric polarization characteristics,which can be used as the evaluation of the severity of scratches.The higher the number of scratches,the smaller the values of S1 and S3 polarization characteristics and the larger the values of S2 polarization characteristics.(3)A simple polarization imaging detection system based on the orthogonal polarization component is studied and designed.The system selects the FPGA chip as the main controller,drives the image sensor for image data acquisition through the IIC protocol,realizes the image data transmission through USB,and realizes the polarization image display in the computer software.The MUX multiplexer is added to the image data acquisition process to realize the selection of two image sensors acquisition data through electrical signals,which simplifies the imaging display interface.After the logical design of each module of the system is completed,the mechanical structure of each component is designed separately,and each component is fixed and installed to eliminate the error caused by jitter.After the system was fixed and installed,the imaging test was conducted,and the imaging results were found to have errors.The causes of the imaging errors were studied,and the errors were calibrated according to the causes of the errors.Finally,the image processing method is used to detect the scratch defects on the acquired orthogonal polarization component images respectively,and scratches is clearly detected,and the detection results match with the actual scratches.Figure [43] table [7] reference [74]...