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:
Dec. 03, 1991
Filed:
Aug. 08, 1990
Albert J Boehnlein, Ypsilanti, MI (US);
Industrial Technology Institute, Ann Arbor, MI (US);
Abstract
An apparatus and method for providing high resolution non-contact absolute contour measurements of an object with moire interferometry. The invention utilizes a projection moire system in which the entire projection system is translated to perform a field shift. The field shift produces a phase shift that is proportional to the height of the object. A coarse three dimensional map of the surface is first obtained from the phase shift. This is combined with high resolution relative measurements of the phase to obtain an absolute Z map of the surface. The invention does not suffer from the 2.pi. ambiguity problem and is suitable for prismatic discontinuous structures. In addition, the present invention is applicable to industrial environments and requires a relatively inexpensive optical system. Further, the field shifting technique is applicable to fast parallel process computers thereby allowing for fast absolute contour generation of prismatic parts.