Method and apparatus to perform a predefined search on data carriers, such as RFID tags

Abstract

A data carrier reader is capable of executing a number of different reading methods. One method performs an inclusive search, identifying all RFID tags having a characteristic data string that appears on a list of characteristic data strings, for example, stored in a buffer. Another method performs and exclusive search, identifying any RFID tags having a characteristic data string that does not appear on the list. In each method, the data carrier reader provides a consistent and intuitive output the user to identify the successful and unsuccessful operations such as locating a desired RFID tag on the list or missing from the list.

We claim:  
     
         1 . A method of automatically searching RFID tags, comprising: 
 storing a number of characteristic data strings in a memory;    reading respective characteristic data strings from each of a number of RFID tags;    comparing each of the read characteristic data strings to the characteristic data strings stored in the memory; and    producing a first human-perceptible indication each time one of the read characteristic data string matches one of the characteristic data strings stored in the memory.    
     
     
         2 . The method of  claim 1  wherein the comparing a first one of the read characteristic data strings occurs before the reading a second one of the characteristic data strings.  
     
     
         3 . The method of  claim 1  wherein the comparing a first one of the read characteristic data strings occurs after the reading at least a second one of the characteristic data strings.  
     
     
         4 . The method of  claim 1 , further comprising: 
 producing a second human-perceptible indication each time one of the read characteristic data strings do not match at least one of the characteristic data strings stored in the memory.    
     
     
         5 . The method of  claim 1 , further comprising: 
 producing a second human-perceptible indication if each of the characteristic data strings stored in the memory matches at least a respective one of the read characteristic data strings.    
     
     
         6 . The method of  claim 1 , further comprising: 
 producing a second human-perceptible indication if each of the characteristic data strings stored in the memory matches at least a respective one of the read characteristic data strings; and    producing a third human-perceptible indication alert if at least one of the characteristic data strings stored in the memory does not match at least one of the characteristic data strings stored in the memory.    
     
     
         7 . The method of  claim 1 , further comprising: 
 transmitting an enable signal to a first one of the RFID tags that has a respective characteristic data string that matches one of characteristic data strings stored in the memory, the enable signal comprising a command to activate a human-perceptible indicator on the first one of the RFID tags.    
     
     
         8 . A method of automatically searching RFID tags, comprising: 
 storing a number of characteristic data strings in a buffer;    reading a respective characteristic data strings from each of a number of RFID tags; and    identifying the RFID tags having the respective characteristic data strings that correspond to the characteristic data strings stored in the buffer.    
     
     
         9 . The method of  claim 8  wherein identifying the RFID tags includes comparing at least a portion of each of the read characteristic data strings to at least one of the characteristic data strings stored in the buffer.  
     
     
         10 . The method of  claim 8  wherein the identifying a first one of the RFID tags occurs before the reading a second one of the RFID tags.  
     
     
         11 . The method of  claim 8 , further comprising: 
 producing a human-perceptible indication corresponding to the number of identified RFID tags.    
     
     
         12 . The method of  claim 8 , further comprising: 
 producing a human-perceptible indication for each of the identified RFID tags.    
     
     
         13 . The method of  claim 8 , further comprising: 
 producing a human-perceptible indication having a characteristic that varies corresponding to the number of identified RFID tags.    
     
     
         14 . The method of  claim 8 , further comprising: 
 producing a second human-perceptible indication each time one of the read characteristic data strings matches at least one of the characteristic data strings stored in the memory.    
     
     
         15 . The method of  claim 8 , further comprising: 
 producing a second human-perceptible indication if all of the characteristic data strings stored in the memory match at least a respective one the read characteristic data strings.    
     
     
         16 . The method of  claim 8 , further comprising: 
 relaying data from the identified RFID tags to a host computer.    
     
     
         17 . The method of  claim 8 , further comprising: 
 transmitting an enable signal to a first one of the RFID tags that has a respective characteristic data string that matches one of characteristic data strings stored in the memory, the enable signal comprising a command to activate a human-perceptible indicator on the first one of the RFID tags.    
     
     
         18 . A method of automatically searching RFID tags, comprising: 
 storing a number of characteristic data strings in a memory;    reading a respective characteristic data string from each of a number of RFID tags;    comparing each of the read characteristic data strings to the characteristic data strings stored in the memory; and    producing a first human-perceptible indication each time one of the read characteristic data string does not matches at least one of the characteristic data strings stored in the memory.    
     
     
         19 . The method of  claim 18  wherein the comparing a first one of the read characteristic data strings occurs before the reading a second one of the characteristic data strings.  
     
     
         20 . The method of  claim 18  wherein the comparing a first one of the read characteristic data strings occurs after the reading at least a second one of the characteristic data strings.  
     
     
         21 . The method of  claim 18 , further comprising: 
 producing a second human-perceptible indication each time one of the read characteristic data strings matches at least one of the characteristic data strings stored in the memory.    
     
     
         22 . The method of  claim 18 , further comprising: 
 producing a second human-perceptible indication if none of the characteristic data strings stored in the memory match any of the read characteristic data strings.    
     
     
         23 . The method of  claim 18 , further comprising: 
 producing a second human-perceptible indication if none of the characteristic data strings stored in the memory match any of the read characteristic data strings; and    producing a third human-perceptible indication if each of the characteristic data strings stored in the memory matches at least a respective one of the read characteristic data strings.    
     
     
         24 . The method of  claim 18 , further comprising: 
 transmitting an enable signal to a first one of the RFID tags that has a respective characteristic data string that does not match any of the characteristic data strings stored in the memory, the enable signal comprising a command to activate a human-perceptible indicator on the RFID tag.    
     
     
         25 . A method of automatically searching RFID tags, comprising: 
 storing a number of characteristic data strings in a buffer;    reading a respective characteristic data string from each of a number of RFID tags; and    identifying the RFID tags having characteristic data strings that do not correspond to the characteristic data strings stored in the buffer.    
     
     
         26 . The method of  claim 25  wherein identifying the RFID tags includes comparing each of the read characteristic data strings to each of the characteristic data strings stored in the memory.  
     
     
         27 . The method of  claim 25  wherein the identifying a first one of the RFID tags occurs before the reading a second one of the RFID tags.  
     
     
         28 . The method of  claim 25 , further comprising: 
 producing a human-perceptible indication corresponding to the number of identified RFID tags.    
     
     
         29 . The method of  claim 25 , further comprising: 
 producing a human-perceptible indication for each of the identified RFID tags.    
     
     
         30 . The method of  claim 25 , further comprising: 
 producing a human-perceptible indication for each of the identified RFID tags.    
     
     
         31 . The method of  claim 25 , further comprising: 
 producing a second human-perceptible indication each time one of the read characteristic data strings matches at least one of the characteristic data strings stored in the memory.    
     
     
         32 . The method of  claim 25 , further comprising: 
 producing a second human-perceptible indication if none of the characteristic data strings stored in the memory match any of the read characteristic data strings.    
     
     
         33 . The method of  claim 25 , further comprising: 
 relaying data from the identified RFID tags to a host computer.    
     
     
         34 . The method of  claim 25 , further comprising: 
 transmitting an enable signal to a first one of the RFID tags that has a respective characteristic data string that does not match one of characteristic data strings stored in the memory, the enable signal comprising a command to activate a human-perceptible indicator on the first one of the RFID tags.