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:
Apr. 07, 1998
Filed:
Dec. 06, 1996
Klaus R Freischlad, Tucson, AZ (US);
Phase Shift Technology, Inc., Tucson, AZ (US);
Abstract
An interferometer particularly suitable for testing the flatness of transparent plano-parallel test pieces employs an extended spatially non-coherent light source. The source is directed to a first beam splitter at an angle of incidence other than normal; and the beam is split into first and second spatially non-coherent divergent wavefronts. A reference surface reflects the first wavefront and a surface under test reflects the second wavefront. A second beam splitter receives and recombines the first and second reflected spatially non-coherent wavefronts; and an interference detector is located to receive the combined reflected wavefronts to produce the interferogram. The distance traveled by the wavefronts from the first beam splitter to the detector is equal, and the optical characteristics of the light path traveled by both wavefronts is the same.