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:
Aug. 30, 2005
Filed:
Jun. 26, 2002
Lyle Shirley, Boxboro, MA (US);
Lyle Shirley, Boxboro, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
In one aspect, the invention relates to an apparatus for monitoring thickness variations of an object having first and second opposing surfaces. The apparatus includes a first source positioned to project a first fringe pattern at a first location on the first surface and a second source positioned to project a second fringe pattern at a first location on the second surface. The apparatus further includes a first detector positioned to detect the first fringe pattern at the first location on the first surface, the first detector generating a first signal in response to the first fringe pattern at the first location. The apparatus also includes a second detector positioned to detect the second fringe pattern at the first location on the second surface, the second detector generating a second signal in response to the second fringe pattern at the first location. The apparatus further includes a processor adapted to calculate variations in the thickness of the object in response to the first and the second signals.