Systems, methods and articles related to machine-readable indicia and symbols

Abstract

A system employs combinations of marking media, each with respective distinguishing spectral characteristics to encode human comprehensible information in, and read human comprehensible information from, machine-readable indicia or symbols. Machine-readable indicia may be a single dot encoding information only in the combinations. Machine-readable symbols may be linear or two dimensional, spatially encoding information in the combinations, as well as spatially. A symbology may map at least the combinations to human-readable symbols or characters. A printer may form indicia or symbols with combinations of marking media. A reader may read indicia or symbols and decode information from at least the combinations of marking media. Different combinations may be visually homogenous, for example gray.

1 .- 50 . (canceled) 
     
     
         51 . An article, comprising:
 a piece of substrate media,   a first symbol character of a symbol located at a first region of the piece of substrate media; and   at least a second symbol character of the symbol located at a second region of the piece of substrate media, the second region spatially distinct from the first region, wherein the second symbol character at the second region is effectively humanly visually indiscernible in color from the first symbol character at the first region.   
     
     
         52 . The article of  claim 51 , further comprising:
 at least a third symbol character of the symbol located at a third region of the piece of substrate media, the third region spatially distinct from the first and the second regions, wherein the third symbol character at the third region is effectively humanly visually indiscernible in color from the first and the second symbol characters at the first and the second regions, respectively.   
     
     
         53 . The article of  claim 51  wherein the first symbol character of the symbol comprises a first combination of at least two of a plurality of marking media based on the information represented by the first symbol character, each of the marking media having at least one respective spectral distinguishing characteristic, the at least one spectral distinguishing characteristic of each one of the marking media different from the at least one spectral distinguishing characteristic of the other ones of the marking media. 
     
     
         54 . The article of  claim 51  wherein the second symbol character of the symbol comprises a second combination of at least two of a plurality of marking media based on the information to be represented by the second symbol character, the second combination different from the first combination. 
     
     
         55 . The article of  claim 51  wherein the first and the second symbol characters are printed symbol characters printed on the substrate media. 
     
     
         56 . The article of  claim 51  wherein the first symbol character comprises a mixture of the marking media of the first combination. 
     
     
         57 . The article of  claim 51  wherein the first symbol character comprises one layer of a first one of the marking media of the first combination and one layer of a second one of the marking media of the first combination, at least one of the layers overlapping at least the other one of the layers. 
     
     
         58 . The article of  claim 51  wherein the symbol characters of the symbol at least partially encoded information in a relative position and the combination of marking media of the symbol characters. 
     
     
         59 . The article of  claim 51 , further comprising:
 a neutralizing marking media that when combined with other marking media results in a humanly perceptible color that renders the respective symbol character effectively humanly visually indiscernible in color from all other symbol characters which form the symbol.   
     
     
         60 . The article of  claim 51  wherein the article takes the form of a piece of identification media, the piece of identification media including a set of human-readable identification information. 
     
     
         61 . The article of  claim 60  wherein symbol characters are distinct from the set of human-readable identification information. 
     
     
         62 . The article of  claim 60  wherein symbol characters are integral with at least part of the set of human-readable identification information. 
     
     
         63 . The article of  claim 60  wherein the piece of identification media takes the form of a driver's license, passport, or identify card, and the set of human-readable identification information includes a name of an individual, a unique identifier, an image of the individual. 
     
     
         64 . A article, comprising:
 a piece of substrate media;   for each of a number of pieces of information represented on the piece of substrate media, a plurality of marks on the substrate media for respective ones of the pieces of information, at least one of the marks on the substrate media formed of a combination of at least two marking media which are not spatially separably distinguishable from one another by an unaided human, each of the marking media having at least one respective spectral distinguishing characteristic, the at least one spectral distinguishing characteristic of each one of the marking media different from the at least one spectral distinguishing characteristic of the other ones of the marking media.   
     
     
         65 . The article of  claim 64  wherein the marks are printed on the substrate media. 
     
     
         66 . The article of  claim 64  wherein a first one of the marks comprises a mixture of the marking media of a first combination of at least two of the marking media. 
     
     
         67 . The article of  claim 64  wherein a first one of the marks comprises one layer of a first one of the marking media of a first combination of at least two of the marking media and one layer of a second one of the marking media of the first combination of the marking media, at least one of the layers spatially overlapping at least the other one of the layers. 
     
     
         68 . The article of  claim 64 , further comprising:
 a neutralizing marking media that when combined with other marking media results in a humanly perceptible color that renders the respective symbol character effectively humanly visually indiscernible in color from all other symbol characters which form the symbol.   
     
     
         69 . The article of  claim 64  wherein the article takes the form of a piece of identification media, the piece of identification media including a set of human-readable identification information. 
     
     
         70 . The article of  claim 69  wherein symbol characters are distinct from the set of human-readable identification information.