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:
Mar. 31, 2009
Filed:
Jun. 28, 2004
Magnus Ekberg, Avesta, SE;
Per-olof Ersson, Falun, SE;
Olle Henningsson, Falun, SE;
Karin Oldberg, Avesta, SE;
Tomas Oldberg, Avesta, SE;
Karl-heinz Rigerl, Falun, SE;
Bosse Wigge, Gustafs, SE;
Magnus Ekberg, Avesta, SE;
Per-Olof Ersson, Falun, SE;
Olle Henningsson, Falun, SE;
Karin Oldberg, Avesta, SE;
Tomas Oldberg, Avesta, SE;
Karl-Heinz Rigerl, Falun, SE;
Bosse Wigge, Gustafs, SE;
Stora Enso AB, Karlstad, SE;
Abstract
A method for analyzing in real-time in a paper machine or board machine the surface structure of a web () of paper or board which method comprises the direction of an imaging system towards a pre-determined area () of the web (), the arrangement of an illumination system to illuminate the region from a pre-determined direction with obliquely incident light, and the arrangement of an image analysis system in association with the imaging system. Furthermore, the method comprises, according to the invention, an image capture step () in which the imaging system is caused to take several digital images of the web under the said oblique incident illumination and during a pre-determined period, which images form an image sequence that images a series of surface sections (″) along a band () in the web (), and an evaluation step () that is carried out by the image analysis system and which comprises an image analysis step (), which in turn comprises a first analysis operation () in which the variance of the pixel values in each pixel row in each image in the image sequence is determined within a pre-determined wavelength band, and a second analysis operation () in which the mean value of the variances of all pixel rows of all images in the image sequence is calculated. The invention also concerns a device for the execution of the method.