US Patent 7660019 Products with data-encoding pattern

A method and apparatus for producing a document having human-readable content and a position identifying encoding pattern. A printer places text or other content onto a substrate, such as paper, and a filter material application system applies transparent filter material to at least a portion of that content to only modify the reflectivity of the content at a predetermined wavelength. Because the reflectivity of the position identifying encoding pattern remains unchanged, it is distinguishable from the content and can be read at the predetermined wavelength. The position identifying pattern can take a number of forms including a number of dots printed at predetermined positions on the substrate on an imaginary grid.