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:
Oct. 11, 1994
Filed:
Dec. 10, 1992
Applicant:
Inventors:
Kiyofumi Matsuda, Tsukuba, JP;
Tomoaki Eiji, Tsukuba, JP;
Thomas H Barnes, Tsukuba, JP;
Shigeru Kokaji, Tsukuba, JP;
Assignees:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356353 ; 386359 ;
Abstract
A shearing interferometer measures the aberration of a lens by passing a beam through the lens, splitting the beam into plural beams with a slightly wedged plate and causing interference between the wavefronts of the beams. The front and rear optical surfaces of the wedged plate are coated with reflective thin films each having a specific reflectance and transmittance.