Non-Contact Interferometric Technique of Measuring the Centering Accuracy of Cylindrical Lens
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
Mechanical methods for measuring centering accuracy used today, such as gauge fittings and test plates, are undesirable because of the highly polished and usually coated surfaces of today's lenses. This non-contact, double-pass interferometric technique will accurately measure the center of curvature without damaging the lens. A gauge fitting or a test plate fitting are methods used in fabricating the lens in an optical shop, during the lapping, grinding, and polishing steps. However, to measure a completed lens today, a non- contact method is mandatory because of the highly polished surfaces and the coatings. The contact methods can damage the surface or a portion of a surface (pinhole-slit effect). A non-contact technique of measurement cannot damage the lens.