A Novel Non-Contact Inspection Method for Measuring the Centering Error of Spherical Singlet Lens

Abstract

As one of the important factors which can seriously affect the image quality, the centering error can be introduced during lens manufacturing and assembling process. Thus, the method to measure the centering error becomes a popular topic in industry. This study mainly introduces one new non-contact measurement method for spherical singlet lens’s centering error. It includes two parts: test lens aligns with rotation axis by using powermeter to measure the unrefracted light power, and centering error is calculated by measuring the center trough position change in the diffraction pattern while rotating the test lens. According to the analysis, with specific optical layout design (fiber laser, collimated lens, aperture, three independent jaws precise rotary stage with test lens, powermeter / CCD with telecentric lens). Based on the results of multi-trials, it determines the alignment of the test lens on the rotary stage and finds the centering error of test lens =5.5798×10^-4 arc. The precision of the result is also discussed. This method has advantages including economics, less complex operation procedure, high precision and sensitivity, large compatibility for all symmetric spherical lens, which provides another new and effective solution to measure the centering error in the lens manufacture and metrology industry.