Texas Instruments Corporation

Joseph F Borchard

Robert Henry Clunn

Charles K Harris

James R Maunder

Walter E Marrable

A doublet lens is optically passively athermalized by choosing two lens materials that have approximately the same Abbe number and substantially different thermal coefficients of refractive index. The ratio of the powers of the lens elements is designed to provide the desired passive athermalization. A diffractive surface is used on one of the lens elements to correct for chromatic aberration. Because the Abbe numbers are approximately the same for the two lens materials, the chromatic correction does not significantly change with temperature. This allows the ratio of the powers of the lens elements to control the focal length of the doublet with temperature being independent of chromatic correction.

Passive athermalization of optics

An inspection system utilizes an image doubler design that includes a plurality of mirrors that effectively folds the object distance by reflecting the image along a folded path. Strobed illumination is used in conjunction with a shutterless camera. Increased image resolution results from an optional anamorphic lens with vertical magnification. The lens assembly includes concentric toroidal lens that are produced from a single piece of machineable optical material.

Growing community of inventors

Garland, TX, United States of America

Joseph F Borchard