Method for measuring surface shape of toric mirror

Abstract

The invention discloses a method for measuring the surface shape of a toric mirror, and the method comprises the steps: firstly, building a CAD model of a toric mirror to be measured through three-dimensional modeling software according to parameter information of the toric mirror to be measured, then importing the CAD model into three-coordinate machine software, measuring and constructing the geometric features of a solid toric mirror based on a three-coordinate machine, and establishing a workpiece coordinate system, wherein the workpiece coordinate system is consistent with a CAD model coordinate system; and finally, carrying out scanning measurement on the solid toric mirror by using the three-coordinate machine, and comparing a scanning result with a theoretical value to obtain measurement result data. The measurement method is based on the three-coordinate measurement technology and has the advantages of being high in operability and high in measurement precision.

Description

technical field [0001] The invention relates to a method for measuring the surface shape of a toric mirror. Background technique [0002] A toric surface, also known as a tire surface, is an optical surface similar to the shape of a tire. The surface has two different curvature radii on two mutually perpendicular cross-sectional circles. In the optical system, the toric surface has unique uses, such as as an anamorphic optical element in an anamorphic optical system, or as a scanning element in an infrared thermal imager, in an extreme ultraviolet spectrometer, a toric mirror is used as a front to greater luminous flux. [0003] The mathematical expression of a toric mirror is as follows: set the intersection line of two toric surfaces perpendicular to each other as the X-axis (optical axis), and the radii of curvature of the two arcs in the symmetrical section are R1 and R2 respectively. The general equation can be expressed for: [0004] [0005] or: [0006] [...

AI Technical Summary

Problems solved by technology

[0007] The surface shape inspection of the toric mirror is difficult, the main reason is that it does not have rotational symmetry, and the vector points on the curved surface have different sagittal heights, so it cannot be directly measured with a spherical interferometer, because there is no rotational symmetry axis, It is also impossible to use the compensation test method based on the lens group to make measurements

There is no aberration point on the toric surface, so the traditional knife-edge shadow method or star point inspection method cannot be used for surface shape inspection

Therefore, there is still a lack of effective means to measure the surface shape of the toric surface. In practice, the profilometer measurement method is usually used to select a line on the toric mirror for measurement, and to evaluate the surface shape error of the toric surface according to the line data , the accuracy of this method is not high, it can only be used for qualitative analysis

Images