The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 14, 1983
Filed:
Jul. 19, 1982
N Balasubramanian, Saratoga, CA (US);
Other;
Abstract
An interferometric system for characterizing the surface of a test object, such as an aspheric surface. A white light interferogram is produced wherein the principal fringe indicates zero optical path difference between a test surface and a reference surface. Wavefronts from either of the test or reference surfaces are translated by incremental amounts. A multi-point detector array is used to make multi-point contrast readings. Points of contrast maxima for each detector point are computed by a statistical determination. A centroid function is preferred. By recording the points of maximum contrast and the incremental wavefront translation, two dimensional plots showing zero optical path differences for the two surfaces are obtained, thereby comparing the test and reference surfaces.