24-10-2012, 01:38 PM
Reading Through Paint
ABSTRACT
Two-dimensional data matrix symbols, which contain encoded letters and numbers, are permanently etched on items for
identification. They can store up to 100 times more information than traditional bar codes. While the symbols provide several
advantages over bar codes, once they are covered by paint they can no longer be read by optical scanners. Since most products
are painted eventually, this presents a problem for industries relying on the symbols for identification and tracking. In 1987,
NASA s Marshall Space Flight Center began studying direct parts marking with matrix symbols in order to track millions of
Space Shuttle parts. Advances in the technology proved that by incorporating magnetic properties into the paints, inks, and
pastes used to apply the matrix symbols, the codes could be read by a magnetic scanner even after being covered with paint
or other coatings. NASA received a patent for such a scanner in 1998, but the system it used for development was not portable
and was too costly. A prototype was needed as a lead-in to a production model. In the summer of 2000, NASA began seeking
companies to build a hand-held scanner that would detect the Read Through Paint data matrix identification marks containing
magnetic materials through coatings.