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. 16, 2007
Filed:
Apr. 17, 2002
Geneviève Moreas, Wanze, BE;
Yves Hardy, Ougree, BE;
Marc Schyns, Roclenge-sur-Geer, BE;
Centre de Recherches Metallurgiques, A.S.B.L., Brussels, BE;
Abstract
The process for the on-line characterization of a surface in motion, preferably a galvannealed sheet, essentially comprises an industrial microscope associated with a stroboscopic laser illumination device, a positioning assembly, an assembly for acquiring and processing images. The obtained view fields vary between 125 μm and 2000 μm in width, the spatial resolution is at least 0.5 μm, and the focussing of the system is precise to a micrometer. The images are taken on a product moving at a speed of between 1 m/s and 20 m/s and are frozen by the use of a stroboscopic illumination device with a duration of illumination of at least 10 ns. The obtained images are processed in several steps. A background average level is first of all regularly evaluated in order to be eliminated from each current image. The processed image is then divided into several zones. The sharpness of each zone is evaluated and stored in memory. A total sharpness coefficient is likewise calculated in order to weight the results subsequently obtained. An operation of binarisation is carried out on the same image using the maximum entropy method in order to detect a maximum number of objects in the image. In the case of a galvannealed steel strip, any object with a center of gravity belonging to a zone in which the sharpness coefficient is too low is eliminated. The objects are classified into very large, large, small and crystalline, the unclassified ones being eliminated. The crystalline objects are those that have a sufficient ratio of height to width. A correlation function established by calibration then supplies the iron percentage present in the coating (correlation: 0.85).