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:
Jan. 05, 1982
Filed:
May. 25, 1972
Jerry A Blodgett, Annandale, VA (US);
Raymond A Patten, Oxon Hill, MD (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
The invention comprises a method and means for measuring the separation been two optical surfaces. A short-coherence-length laser pulse is projected upon two optical surfaces separated by a distance, d. The reflected, coincident beams are directed into a Michelson interferometer in which one plane mirror is replaced by a stepped mirror. The beams reflected from the two mirrors are directed onto a film where they form interference images. A formula using the number of channels, n, between successive interference fringes and the step width of the stepped mirror is used to calculate d.