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:
Sep. 17, 2013
Filed:
Apr. 27, 2011
Michael K. Burkland, Tucson, AZ (US);
Michael K. Burkland, Tucson, AZ (US);
Raytheon Company, Waltham, MA (US);
Abstract
In an absolute position encoder, a multi-spectral light source illuminates a position on a topographic surface at an angle of incidence determined from a vector normal to the surface. A target on, and positionally-registered to, the topographic surface comprises a variable grating that diffracts the incident light to form a multi-spectral diffraction pattern in which the angular dispersion of the diffraction pattern varies with the absolute position of the incident light along the grating. A chromatically responsive sensor detects a narrow band of the diffraction pattern through an entrance aperture positioned at an angle of detection determined from the vector normal to the topographic surface and outputs a signal responsive to the change in the angular dispersion of the detected narrow band of the diffraction pattern. The source/sensor unit maintains (within an acceptable noise tolerance) its geometric relationship to the vector normal to the topographic surface at the position of illumination. A processing element uses a system transfer function to map the detected signal to an absolute-position on the topographic surface.