Image Number 2 for United States Patent #7502126.
A system for tracking the spatial position/motion of an article conveyed along a feed path. The system comprises a reflective surface disposed along the feed path of the article and an optical scanning device disposed remotely from the reflective surface such that the moving article is interposed therebetween. The optical scanning device is operative to (i) transmit light energy along a length of the reflective surface, (ii) receive light energy returned from the reflective surface and (iii) determine the spatial position of the article based upon a condition of the optical path, i.e., whether the optical path is present or interrupted. A break in the optical path is sensed by the optical scanning device and interpreted by the signal processor to determine the spatial position/motion of the moving article.