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Non-Contact Curvature Measurement Technique

IP.com Disclosure Number: IPCOM000064995D
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
LeMaster, RJ [+details]

Abstract

The radius of curvature of a spherical surface can be measured by a system using a lens of known numerical aperture. The surface 1 in Fig. 1 is illuminated by a collimated beam 3 through the objective lens 2 of the system. The objective lens will relay an image of a bright spot corresponding to the points on the surface which reflect illuminating rays back within the aperture 4 of lens 2. Those points which reflect rays 5 back outside the aperture of lens 2 will not be imaged by it. If the optical axis 6 of lens 2 in Fig. 2 intersects the center of curvature 7 of the surface 1, the radius r of curvature of the surface can be determined by measuring the diameter d of the bright spot. (Image Omitted)