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:
Feb. 23, 2016
Filed:
Dec. 17, 2010
Lawrence Bieber, Colorado Springs, CO (US);
Michel Willemin, Prêles, CH;
Lawrence Bieber, Colorado Springs, CO (US);
Michel Willemin, Prêles, CH;
EM Microelectronic-Marin SA, Marin, CH;
Abstract
A method for measuring relative motion between an illuminated surface and an optical sensing device comprising a coherent light source and a photodetector array is described. The method includes illuminating under a determined gradient, using the coherent light source, a surface portion at a determined flash rate; detecting, using the photodetector array, speckled light intensity pattern of the illuminated surface portion for a first flash; detecting a second speckled light intensity pattern of the illuminated surface portion for a second flash; extracting motion features of two different types from the detected first and second speckled light intensity patterns; determining a measurement of relative motion between the optical sensing device and the illuminated surface portion based on comparison of motion features extracted; wherein the method further comprises a filtering step in order to adjust, and preferably decrease, the number of motion features used in the step of determining a measurement of relative motion.