The Influence of Planar Array Charge-Coupled Device (CCD) Staggered Imaging on the Detection Precision of the Tool Setting Gap when Using Laser Diffraction
G-F. Shi, F-J. Guo, H. Zhang, X. Wang, D-W. Yu and G-Q. Shi
The tool setting technology by laser diffraction is a method of evaluating the tool setting precision by detecting the distance between the light intensity peak points of the first-order diffraction fringes formed on the charge-coupled device (CCD). In order to solve the problem that the planar array CCD has low detection accuracy due to the limitation of sampling density during conventional imaging. The sampling density of the tool setting diffraction image is improved by using the planar array CCD staggered imaging technique in this paper, detailed methods are as follows: The single planar array CCD is integrally shifted by the combination of the nano-lifting platform and the high precision two-dimensional (2-D) translation stage, is used to image the tool setting gap with a certain object distance. And then, four diffraction-strip images with complementary information are obtained, which we can use to stitch the image information according to the translocation relationship between each image, and finally a higher resolution diffraction image is obtained. Through detecting the distance between the light intensity peak points of the first-order diffraction fringes of higher resolution diffraction image, the detection precision of the tool setting gap of laser diffraction is improved 50 to 70 μm. The results indicate that the detection precision of tool setting gap can be improved effectively by increasing the image sampling density with the planar CCD staggered imaging technology.
Keywords: Diode laser, charge-coupled device (CCD) laser diffraction, planar array, staggered imaging, sampling density, fringe images, first order diffraction stripes