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:
Jul. 27, 1999
Filed:
Aug. 11, 1998
Conrad Stenton, Midland, CA;
Eric Ao, Midland, CA;
Raytheon Company, Lexington, MA (US);
Abstract
A method and apparatus for testing elliptical mirrors is provided which reduces the length of the test apparatus by half, provides for precise location of the focus of the interferometer beam, and precise measurement of the distance between foci of the elliptical mirror under test. A small reflective sphere (10) with an optical passageway (15) through its center is used to locate the focal point (f.sub.2) of the interferometer (5) within interferometric precision. A plane mirror (30) is placed half way between the focal points of the ellipse (20) under test with one of the elliptical foci coincident with the interferometer focal point (f.sub.2). The elliptical mirror (20) under test is placed with reflective concave surface facing away from the interferometer (5) to receive light reflected from the plane mirror (30). The optical passageway (15) is sized to emit a volume of light to fill the elliptical mirror surface (22) after reflection from the plane mirror (30). The optical passageway (15) is also sized for the sphere (10) to reflect substantially all of the light incident upon it from the ellipse (20).