The data acquisition device comprises a projecting device for projecting the light emitted by a radiation source onto a section of a marked surface, and an optical unit for recording and reproducing the reflected light on a screen sensor converting the reflected light into a sequence of electronic signals....http://www.google.com.au/patents/US6243503?utm_source=gb-gplus-sharePatent US6243503 - Data acquisition device for optical detection and storage of visually marked and projected alphanumerical characters, graphics and photographic picture and/or three dimensional topographies
