Spherical surface automatic centering method applied to spherical surface optical element surface defect detection

The invention discloses a spherical surface automatic centering method applied to spherical surface optical element surface defect detection. The method comprises the following steps that a spherical surface centering unit is initialized, and then a spherical surface optical element is moved to an initial position; Z-direction scanning is performed, and the clearest crosshair image is found by utilizing an image entropy definition evaluation function in the scanning process; then whether the crosshair is a surface image or a spherical center image is judged; if the crosshair is the surface image, the spherical center image is found through scanning along Z-direction, and radius of curvature of the spherical surface optical element is measured; if the crosshair is the spherical center image, the optical axis of the spherical surface optical element is enabled to be overlapped with the optical axis of the spherical surface centering unit through movement; and finally fitting is performed on the center of the crosshair image by a least square method optimal circle fitting method to obtain movement tracks, calculation of the maximum deviation of the crosshair image is completed, and the maximum deviation is judged so that shafting consistency adjustment is completed. Automatic centering of the spherical surface optical element is realized so that centering efficiency and centering precision are greatly enhanced.