Machine-readable symbols

Abstract

A variety of forms of machine-readable symbols are disclosed, as well as methods and systems of constructing machine-readable symbols, methods and systems of acquiring machine-readable symbols, and methods and systems of decoding machine-readable symbols.

1 .- 140 . (canceled) 
     
     
         141 . A machine-readable symbol, comprising:
 a first machine-readable symbol instantiated on an object, said machine-readable symbol having a number of code elements that can be read by one or more methodologies to yield code values, said code elements constituting a basic unit of said symbol that yields said value independent of any other code element and free from decoding any other code value of said machine-readable symbol;   said code elements comprising at least three non-binary code elements including a first code element having a first value, a second code element having a second value different than said first value, and a third code element having a third value different from said first and second values.   
     
     
         142 . A machine-readable symbol as set forth in  claim 141 , wherein said code elements include four non-binary code elements having four different values. 
     
     
         143 . A machine-readable symbol as set forth in  claim 141 , wherein each of said non-binary code elements are readable by a combination of two different methodologies. 
     
     
         144 . A machine-readable symbol as set forth in  claim 143 , wherein each of said two different methodologies involves an optical characteristic. 
     
     
         145 . A machine-readable symbol as set forth in  claim 143 , wherein said two different methodologies comprise a reflectance methodology and a topographic methodology. 
     
     
         146 . A machine-readable symbol as set forth in  claim 145 , wherein said topographic methodology yields information concerning a depth of a code element under analysis. 
     
     
         147 . A machine-readable symbol as set forth in  claim 145 , wherein said two different methodologies yield a quaternary symbol value set composed of first and second states of said first methodology and first and second states of said second methodology. 
     
     
         148 . A machine-readable symbol as set forth in  claim 147 , wherein quaternary symbol value set includes values corresponding to white-surface, white-deep, black-surface, and black-deep. 
     
     
         149 . A machine-readable symbol as set forth in  claim 141 , wherein the first machine-readable symbol comprises a barcode printed on the surface of the object. 
     
     
         150 . A machine-readable symbol as set forth in  claim 141 , wherein the first machine-readable symbol comprises a barcode printed on a conformal layer applied over the surface of the object. 
     
     
         151 . A method for decoding a first machine-readable symbol, comprising the steps of:
 acquiring an image of the machine-readable symbol;   identifying an image portion of said image corresponding to an element of said machine-readable symbol;   processing the identified image portion using one or more methodologies to determine a code value from a value set corresponding to the code element, said value set having at least three possible values.   
     
     
         152 . A method as set forth in  claim 151 , wherein said value set includes at least four different values. 
     
     
         153 . A method as set forth in  claim 151 , wherein said step of processing comprises:
 processing the image to separately evaluate first and second characteristics of the image portion:   applying a first methodology to obtain first information from the evaluated first characteristic; and   applying a second methodology to obtain second information from the second evaluated characteristic; and   using the first information and the second information to determine said code value from said set of code values.   
     
     
         154 . A method set forth in  claim 153 , wherein each of said two different methodologies involves an optical characteristic. 
     
     
         155 . A method as set forth in  claim 153 , wherein said two different methodologies comprise a reflectance methodology and a topographic methodology. 
     
     
         156 . A method as set forth in  claim 155 , wherein said topographic methodology yields information concerning a depth of a code element under analysis. 
     
     
         157 . A method as set forth in  claim 155 , wherein said two different methodologies yield a quaternary symbol value set composed of first and second states of said first methodology and first and second states of said second methodology. 
     
     
         158 . A method as set forth in  claim 157 , wherein quaternary symbol value set includes values corresponding to white-surface, white-deep, black-surface, and black-deep. 
     
     
         159 . A method as set forth in  claim 151 , wherein the first machine-readable symbol comprises a barcode printed on the surface of the object. 
     
     
         160 . A method as set forth in  claim 151 , wherein the first machine-readable symbol comprises a barcode printed on a conformal layer applied over the surface of the object.