Research On Surface Characterizationtesting Technology Of Optical Element Based On Projection Method

In the manufacturing of optical instruments, to study the geometric characteristics of the surface of the optical components,to improve the quality of the machined surface of the optical element, and to explore the performance of optical components, and so has a crucial importance. In this paper, it explores a combination of detection methods based on line structure light projection and solid vision measurement.Experimental platform based on the theoretical knowledge of the lens surface shape detection and reconstruction simulation using MATLAB and VC++software. The main work carried out as follows:First, it elaborated stage of domestic and foreign common method used to surface shape of the optical components, analysis and comparison of the advantages and disadvantages of each of them,and then clears the practical significance of the projection method to detect the surface shape of the optical components technology and engineering value in use.Second, according to the optical triangulation method and binocular vision measurement method detection principle, it establishes and improves the mathematical model of the line structured light binocular 3D vision measurement system, it designs the hardware structure of the surface by the laser, CMOS cameras and other components constitute the line structured light kind sweep, and combined with the completion of the existing technical conditions to build experimental platform projection method to detect the surface shape of the optical elements.Third, a detailed analysis of camera imaging principle of the model and the relations between the transformation of different coordinate system, and the ideal camera calibration work is completed, while it explores the impact on the measurement accuracy of the system, and provides a basis for the image data processing.Fourth, in order to obtain good quality of image pairs, to provide better data for the stereo matching, it has the camera acquisition to the original image filtering and the histogram equalization image preprocessing.Fifth, by exploring under two different perspectives presence viewpoint differences, geometry and stereo matching process between the grayscale distortion and noise in the picture, it is purpose to restore the depth of the image information.Sixth, it completes simulation of three-line laser irradiation by using MATLAB software fitting, makes the triangulation method for the spatial discrete points by using stereo vision technology, at the same time, analysises the three-dimensional reconstruction experimental results about the projection method detection surface shaped, compared with ZYGO interferometer measurement results, then verifies the feasibility of the experimental program.Seventh, the laboratory research and analysis for the results, and points out the projection method of detecting optical component surface shape part still need to improve and perfect this method and the direction to delve into.Based on projection parts detection technology research, we completed the shape of the lens surface detection,and the experimental results show that the method of test results can satisfy the detection requirements of paper design which has the feasibility.