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:
Nov. 01, 2011
Filed:
Nov. 08, 2006
Rudolf Waelti, Schwarzenburg, CH;
Urs Buri, Maus, CH;
Jörg Breitenstein, Bern, CH;
Haag-Streit AG, Koniz, CH;
Abstract
A Michelson-interferometer which has two reference arms and a short coherence length is used for the method and apparatus for measurement of geometric values on transparent or diffuse objects (). The basic optical delay times of the reference arms () are chosen in such a manner that they result in an optical delay time difference corresponding to a layer thickness, as a geometric value. The at least two reference arm beams () are passed to a single rotating path-length variation element (), with a mutual spatial offset angle (dw). A delay-time change, which is dependent on the rotation angle, of the reference arm beams is produced as a function of a rotation angle caused by rotation, in order to allow a delay-time change caused by the path-length variation element () to be applied successively to the basic optical delay times in the reference arms (). A topography as a further geometric value is obtained by projection of a light-intensity structure onto a surface to be measured, and by measurement of its image.