Core shift measuring method

Abstract

The invention provides the method for measuring amount of deviation core, comprising the following steps: getting the difference deltar of locus radius r1 and r2 which are formedon image surface from checking surface (10A) and installing surface (10B), multiplying thedeltar by K, which is ratio of distance in real space position and distance of imaging surface, and getting the amount of deviation core. Even if there is deviation, the invention can easily and accurately measure the amount of deviation core.

Description

technical field [0001] The invention relates to a method for measuring the eccentricity of an inspected surface of an optical element such as a lens. Background technique [0002] As an important item in the evaluation and inspection of lenses, there is the measurement of the amount of eccentricity on the lens surface. [0003] The amount of eccentricity of the lens surface is expressed by the amount of deviation between the center of curvature of the lens surface and the central axis of the lens. [0004] As a method of measuring such an eccentric amount, a method called an autocollimation method described in Patent Document 1 and the like below is known. For example, Figure 8 The shown eccentricity measurement method is by adopting the method of the emission type eccentricity measurement device that has applied the self-collimation method, and it comprises: base 122, the lens (spherical lens) 110 that is checked is arranged so that its central axis is The center is rota...

AI Technical Summary

Problems solved by technology

[0010] However, in the mechanism for moving the base 122 on which the lens to be inspected 110 is installed or the measuring optical system 131 in the direction of the optical axis, there are actually machining errors.

Therefore, there is a slight misalignment between the rotation axis of the base 122 and the optical axis of the lens 110 to be inspected, or between the rotation axis of the base 122 and the optical axis of the optical system 131 for measurement, and the like. The existence of offset will make it difficult to improve the measurement accuracy of eccentricity

In particular, the existence of such a small offset that hinders the improvement of the measurement accuracy of the eccentricity amount becomes a big problem as the performance of optical equipment increases.

[0011] Of course, if the optical adjustment is performed so that the center of curvature of the mounting surface is located on the lens rotation axis, the measurement accuracy can be improved, but such optical adjustment requires a lot of labor and makes it unbearable.

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