Document processing system and method for associating metadata with a physical document while maintaining the integrity of its content

An apparatus for scanning a physical document bearing content visible in a human visible spectrum, said apparatus comprising:

• a reader, including:
• a first light source defined at a first angle that is acute relative to said physical document and operable to project light upon said physical document;
• a second light source defined at a second angle that is acute relative to said physical document and operable to project light upon said physical document, said first angle opposite to said second angle;
• and
• a scanner operable to read a tag comprising metadata generated based on an attribute of said physical document, said tag printed on said physical document with a first ink substantially invisible in said human visible spectrum and overlapping at least a portion of said content printed on said physical document using a second ink that is visible in said human visible spectrum, said scanner comprising a photomultiplier tube that detects a fluorescent signal produced by said first ink to read said tag, said tag comprising a start bar field and a tag field,
• said start field comprising:
• a plurality of start field bars, a bar width of each of said first plurality of start field bars being equal;
• and
• a plurality of start field spaces, each start field space of the plurality of start field spaces being defined between adjacent start field bars of said plurality of start field bars, a space width of each of said start field spaces being equal, said space width of each of said start field spaces being an integer multiple of said bar width of said plurality of start field bars, such that said plurality of start field bars are spaced equally apart and said space width of each start field space between adjacent start field bars being proportional to said bar width, said tag field comprising:
• a plurality of tag field bars having a same bar width as said bar width of said plurality of start field bars;
• and
• said plurality of tag field bars being unequally spaced apart, and
• said photomultiplier tube defined between said first light source and said second light source at a perpendicular angle relative to said physical document;
• and
• a processor operable to compare said metadata with an index of an image of said physical document, said index generated based on said metadata, said reader sorting said physical document routing said physical document to a location when said first metadata matches said index.

An apparatus for processing a physical document bearing content visible in a human visible spectrum and metadata regarding said physical document printed in a first ink substantially invisible in said human visible spectrum, said apparatus comprising:

• a reader operable to read a tag comprising said metadata using light outside of said spectrum, said light output from both a first light source and a second light source, said first light source defined at a first angle that is acute relative to said physical document, said second light source defined at a second angle that is acute relative to said physical document, said first angle opposite to said second angle, said tag overlapping at least a portion of said content printed on said physical document using a second ink that is visible in said human visible spectrum, said tag comprising a start bar field and a tag field,
• said start field comprising:
• a plurality of start field bars, a bar width of each of said first plurality of start field bars being equal;
• and
• a plurality of start field spaces, each start field space of the plurality of start field spaces being defined between adjacent start field bars of said plurality of start field bars, a space width of each of said start field spaces being equal, said space width of each of said start field spaces being an integer multiple of said bar width of said plurality of start field bars, such that said plurality of start field bars are spaced equally apart and said space width of each start field space between adjacent start field bars being proportional to said bar width,
• said tag field comprising:
• a plurality of tag field bars having a same bar width as said bar width of said plurality of start field bars;
• and
• said second plurality of tag field bars being unequally spaced apart,
• said reader defined between said first light source and said second light source at
• a perpendicular angle relative to said physical document;
• and
• a processor coupled to said reader and configured to route said physical document to a location based on a comparison between said metadata and an index associate with an image of said physical document, said metadata generated based on an attribute of said physical document and said index generated based on said metadata.

A method of processing a physical document bearing content visible in a human visible spectrum and metadata regarding said physical document printed in a first ink substantially invisible in said human visible spectrum, comprising:

• illuminating said physical document with a light outside of said human visible spectrum, said light output from both a first light source and a second light source, said first light source defined at a first angle that is acute relative to said physical document, said second light source defined at a second angle that is acute relative to said physical document and said first angle opposite to said second angle;
• reading, via a tag reader defined between said first light source and said second light source at a perpendicular angle relative to said physical document, a tag in response to said illumination, said tag overlapping at least a portion of said content printed on said physical document using a second ink that is visible in said human visible spectrum, said tag encoding said metadata generated based on an attribute of said physical document, and said tag comprising a start bar field and a tag field,
• said start field comprising:
• a plurality of start field bars, a bar width of each of said plurality of start field bars being equal;
• and
• a plurality of start field spaces, each start field space of the plurality of start field spaces being defined between adjacent start field bars of said plurality of start field bars, a space width of each of said start field spaces being equal, said space width of each of said start field spaces being an integer multiple of said bar width of said plurality of start field bars, such that said plurality of start field bars are spaced equally apart and said space width of each start field space between adjacent start field bars being proportional to said bar width,
• said tag field comprising:
• a plurality of tag field bars having a same bar width as said bar width of said plurality of start field bars;
• and
• said plurality of tag field bars being unequally spaced apart;
• and
• routing said physical document to a location based on a comparison between said metadata and an index associated with an image file containing an image of said physical document, said index generated based on said metadata.