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:
Jan. 25, 2011
Filed:
Jun. 24, 2005
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
There is described a method for measuring relative motion between an illuminated portion of a surface and an optical sensing device comprising a coherent light source and a photodetector array, the method comprising the steps of illuminating under a determined gradient by means of the coherent light source the surface portion at a determined flash rate; detecting by means of the photodetector array speckled light intensity pattern of the illuminated portion of the surface for a first flash; detecting a second speckled light intensity pattern of the illuminated portion of the surface 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 the relative motion between the optical sensing device and the illuminated surface portion based on a comparison of motion features extracted; wherein before the step of determining a measurement of the relative motion, the method further comprises the step of keeping only pairs of neighbouring motion features including one motion feature of both different types.