Patent ID: 8497983

Claim:
A system for obtaining a signature from an article, the article having a scan area on a surface of the article from which a signature of the article may be read, the system comprising: a signature generator arranged to generate a signature from the article by directing coherent radiation onto a plurality of regions in the scan area; collecting a set comprising groups of data points from signals obtained when the coherent radiation scatters from the regions in the scan area wherein different ones of the groups of data points relate to scatter from the respective different regions of the scan area; and determining a signature of the article from the set of data points; the signature generator including a scan head comprising an optical source operable to direct coherent radiation onto the scan area and a detector arrangement operable to collect the data points by detecting the scattered coherent radiation; a camera operable to capture an image of the surface of the article; an image comparator arranged to compare the captured image with a reference image of an article of the same class which includes the scan area of that article, to determine the location and orientation of the scan area on the said article; and a drive assembly arranged to translate and/or rotate the scan head into alignment with the detected scan area on the article, in response to the determination of the location and orientation of the scan area.