Method for measuring ultra-large curvature radius through transverse subtraction and differential confocal processing

Abstract

The invention discloses a method for measuring an ultra-large curvature radius through transverse subtraction and differential confocal processing and belongs to the technical field of optical precision detection. According to the method, in a confocal measurement system, firstly, a large and small virtual pinhole detection area (image area) is set through software on a CCD detected airy disk image through software, two confocal characteristic curves detected by a CCD are subjected to subtraction processing to sharpen the confocal characteristic curves, finally, all characteristic points in ultra-large curvature radius measurement are subjected to high-precision fixed focusing by use of the characteristic that a zero point of a transverse subtraction and differential confocal characteristic curve and a focus of the measurement system correspond to each other precisely, and further, high-precision measurement of the ultra-large curvature radius is realized. The method provides a brand-new technical way for high-precision measurement of the ultra-large curvature radius.

Description

technical field [0001] The invention relates to a method for measuring a super large curvature radius by lateral subtraction and differential confocal, and belongs to the technical field of precision measurement of optical element parameters. Background technique [0002] In optical systems, inertial navigation systems, and aircraft engine transmission systems, spherical elements are one of the most important elements. The radius of curvature of the spherical element is the most critical parameter to determine the overall performance of the element, so it is of great significance to measure the radius of curvature of the spherical element with high precision. [0003] For the measurement of the radius of curvature of a spherical surface, the existing measurement methods are: spherical template method, spherometer method, self-collimation method, interferometer method, knife-edge meter method, Newton ring method, laser shearing interferometer method and Mohr Segregation meth...

AI Technical Summary

Problems solved by technology

[0012] 1) The focal depth is long, affected by the diffraction effect, the focus accuracy of "cat's eye" and "confocal position" is low;

[0013] 2) The radius is large and the measurement optical path is long, which is difficult to measure precisely due to the interference of the measurement environment and system drift;

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