Abstract:
A method that allows one to mark information with a pencil on a material equipped with a RFID type circuit, and have the marked information stored in a RFID circuit that is a component of a personal identification system and/or a document identification system. The marked entered information may be corrected by erasing the written information with a pencil eraser and writing new information on paper with a pencil. Information may also be marked into a RFID circuit and have the marked information stored in the RFID circuit by utilizing a standard ink jet computer printer to print lines on paper equipped with a RFID type circuit, by having the printed lines perform the function of wires.

Description:
[0001]    This Application claims the benefit of the filing date of U.S. Provisional Application No. 60/419,361 filed Oct. 18, 2002, which is owned by the assignee of the present Application. 
     
    
     
       CROSS REFERENCE TO RELATED APPLICATIONS  
         [0002]    Reference is made to commonly assigned co-pending patent applications Docket No. F-633 filed herewith entitled “METHOD FOR FIELD PROGRAMMING RADIO FREQUENCY IDENTIFICATION DEVICES THAT CONTROL REMOTE CONTROL DEVICES” in the names of Jeffrey D. Pierce, Brian M. Romansky, Thomas J. Foth, and Anand V. Chhatpar; Docket No. F-635 filed herewith entitled “METHOD FOR FIELD PROGRAMMABLE RADIO FREQUENCY IDENTIFICATION TESTING DEVICES FOR TRANSMITTING USER SELECTED DATA” in the names of Thomas J. Foth, Brian M. Romansky, Jeffrey D. Pierce, Andrei Obrea, and Anand V. Chhatpar; Docket No. F-637 filed herewith entitled “METHOD FOR FIELD PROGRAMMABLE RADIO FREQUENCY IDENTIFICATION DEVICES TO PERFORM SWITCHING FUNCTIONS” in the names of Andrei Obrea, Brian Romansky, Thomas J. Foth, Jeffrey D. Pierce, and Anand V. Chhatpar; Docket No. F-638 filed herewith entitled “METHOD FOR FIELD PROGRAMMING RADIO FREQUENCY IDENTIFICATION LABELS” in the names of Thomas J. Foth, Brian M. Romansky, Jeffrey D. Pierce, and Anand V. Chhatpar; Docket No. F-639 filed herewith entitled “METHOD FOR FIELD PROGRAMMING RADIO FREQUENCY IDENTIFICATION RETURN FORMS” in the names of Jeffrey D. Pierce, Thomas J. Foth, Brian M. Romansky, Andrei Obrea, and Anand V. Chhatpar; and F-640 filed herewith entitled “METHOD AND APPARATUS FOR FIELD PROGRAMMING RADIO FREQUENCY IDENTIFICATION DEVICES” in the names of Brian M. Romansky, Thomas J. Foth, Jeffrey D. Pierce, Andrei Obrea and Anand V. Chhatpar.  
         FIELD OF THE INVENTION  
         [0003]    This invention pertains to electronic circuits and, more particularly, to programmable radio frequency document identification devices.  
         BACKGROUND OF THE INVENTION  
         [0004]    RFID tags and RFID systems have been used for employee personal identification in automated gate sentry applications protecting secured buildings or areas and in document identification systems that contain RFID tags that are affixed to the document. The user of an RFID tag contained in a personal identification badge or the holder of a document containing a RFID tag would place the RFID tag near a device that transmits an excitation signal to the RFID tag in a manner that the RFID tag would communicate the information stored in the RFID tag back to the device.  
           [0005]    One of the problems with the above was that the manufacturer of the tags programmed the information stored in the RFID tags. Thus, the manufacture of the tags would know confidential information regarding the party wanting to protect secured buildings, secured areas and/or documents.  
           [0006]    One method utilized by the prior art that avoided giving the RFID manufacturer the party&#39;s confidential information involved establishing a database that was related to the information stored in the RFID tags. For instance, if the number  1000  was stored in a RFID tag the number  1000  may represent the employee John Doe in the related database.  
           [0007]    The prior art attempted to solve the foregoing problem by providing RFID writers to parties that are protecting several buildings, several areas and/or secured documents. RFID writers are expensive.  
         SUMMARY OF THE INVENTION  
         [0008]    This invention overcomes the disadvantages of the prior art by providing a method that allows one to mark information with a pencil or conductive ink on a material equipped with a RFID type circuit, and have the marked information transmitted by the RFID circuit. The material may be any cellulose type product, i.e., paper, cardboard, chipboard, wood or plastic, fabric, animal hide, etc. The marked entered information may be corrected by erasing the written information with a pencil eraser and writing new information on paper with a pencil. Information may also be marked into a RFID circuit and have the marked information transmitted by the RFID circuit by utilizing a standard ink jet computer printer to print lines on paper equipped with a RFID type circuit, by having the printed lines perform the function of wires. The aforementioned printed information may be modified by having an individual connect different printed wires by drawing a penciled line between the wires.  
           [0009]    This invention accomplishes the foregoing by utilizing the RFID serial number generation portion of the RFID circuit that is used when the RFID circuit is being read. In the prior art, the bits used to encode one&#39;s and zero&#39;s into the generation portion of the RFID circuit were typically fixed. This invention utilizes the serial number generation portion of the RFID circuit by exposing on a piece of paper some or all of the bits left open or closed to represent a binary values, i.e., ones or zeros. A user may complete the RFID serial number storage portion of the RFID circuit by filling in the space between the connections with a pencil to alter the binary values. Alternatively, the serial number generation portion of the RFID circuit may be exposed on a piece of paper with all of the connections made, and a user may break a space between the connections with a sharp instrument or hole punch to alter the binary values. Alternatively, the serial number generation portion of the RFID circuit may have some of the bits all ready left open or closed to represent a unique number.  
           [0010]    An additional advantage of this invention is that a party will be able to program their own RFID employee personal identification devices and their own RFID document identification devices.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a block diagram of a prior art RFID circuit;  
         [0012]    [0012]FIG. 2A is a drawing of a circuit  24  that replaces memory array  21  of FIG. 1 showing how programming of the bits may be accomplished by making the bits externally available for programming RFID circuit  10 ;  
         [0013]    [0013]FIG. 2B is a drawing of a circuit  300  that is an alternate representation of circuit  24 , that replaces memory array  21  of FIG. 1 showing how programming of the bits may be accomplished by making the bits externally available for programming RFID circuit  10 ;  
         [0014]    [0014]FIG. 3 is a drawing showing sensor circuit  25  of FIG. 2A in greater detail;  
         [0015]    [0015]FIG. 4 is a seller furnished form to be completed by a buyer returning goods to a seller;  
         [0016]    [0016]FIG. 5 is a drawing showing how a document has markings in order to enable a RFID modified circuit to identify the document; and  
         [0017]    [0017]FIG. 6 is a drawing showing circuit  325  of FIG. 5 in greater detail.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0018]    Referring now to the drawings in detail, and more particularly to FIG. 1, the reference character  10  represents a prior art RFID circuit. Circuit  10  may be the model MCRF 200 manufactured by Microchip Technology, Inc. of 2355 West Chandler Blvd, Chandler, Ariz. 85224. RFID reader  11  is connected to coil  12 , and  12  is coupled to coil  13 . Coil  13  is connected to modulation circuit  14 . Modulation circuit  14  is connected to clock generator  15  and rectifier  16 . Modulation control  17  is coupled to modulation circuit  14 , clock generator  15  and counter  18 . Counter  18  is coupled to column decode  20 . Row decode  19  is coupled to memory array  21 , and array  21  is coupled to modulation control  17 . It would be obvious to one skilled in the art that a battery may be used to supply power to circuit  10 .  
         [0019]    Reader  11  has a transmitter mode and a receiver mode. During the transmit mode of reader  11 , reader  11  transmits a radio frequency signal for a burst of time via coil  12 . After the transmission of a signal by reader  11 , reader  11  turns into a receiver. Coil  12  is inductively linked with coil  13 , and coil  13  receives the radio frequency signal from coil  12  and converts the aforementioned signal into inductive energy, i.e., electricity. When coil  13  has sufficient energy, coil  13  will cause clock generator  15  to generate timing pulses which drive counter  18 . Counter  18  drives row decode  19  which causes memory array  21  to read the fixed bit data pattern stored in memory array  21  one bit at a time. As the data bits are being read by array  21 , the data bits are transmitted to modulation control circuit  17 . Control circuit  17  sends the data bits to reader  11  via modulation circuit  14  and coils  13  and  12 .  
         [0020]    [0020]FIG. 2A is a drawing of a circuit  24  that replaces memory array  21  of FIG. 1 showing how programming of the bits may be accomplished by making the bits externally available for programming RFID circuit  10 . A plurality of sensor circuits  25  is contained in circuit  24 . Sensor circuits  25  are labeled SC 1  SC 2  SC 3  . . . Sc n . Line  29  is connected to SC 1  and graphite contact  52  and line  30  is connected to SC 2  and graphite contact  53 . Line  31  is connected to SC 3  and graphite contact  54  and line  32  are connected to SC n  and graphite contact  55 . There is a sensor circuit  25  for each graphite contact. The description of FIG. 4 will describe how information may be entered into circuit  24  via graphite contacts  52 - 55 . SC 1  has an input  33 , which enables the data output  34 . Input  33  is connected to one of the n lines  37 , and data output  34  is connected to data line  36  and pull up resistor  35 . Data line  36  is connected to modulation control  17  (FIG. 1).  
         [0021]    When counter  18  selects the value 1, column decode  20  will enable line  33 , which will cause the same logic level that is on graphite contact  52  to be placed on data output  34 . When line  33  is not selected, the value on graphite contact  52  does not have any influence on the data output line  34 . Enable outputs  33  for SC 1  . . . SC n  are bundled together in lines  37  so that only one line  37  is turned on at a time. Lines  37  are connected to column decode  20 . Column decode  20  is connected to counter  18 , and counter  18  is connected to row decode  19 . Counter  18  generates a sequence of numbers from 1 through n to enable a different line  37  in sequential order. Thus, data line  36  will receive the data outputs  34  from SC 1  . . . SC n  at different times.  
         [0022]    [0022]FIG. 2B is a drawing of a circuit  300  that is an alternate representation of circuit  24 , that replaces memory array  21  of FIG. 1 showing how programming of the bits may be accomplished by making the bits externally available for programming RFID circuit  10 . Circuit  300  includes AND gates  301 ,  302 ,  303  and  304  and OR gate  305 .  
         [0023]    One of the inputs of AND gate  301  is connected to column decode  20  and the other input to AND gate  301  is connected to one of the ends of resistor  322 , one of the ends of diode  306  and one of the ends of diode  314 . The other end of resistor  322  is connected to ground. The other end of diode  306  is connected to one of the terminals of toggle switch  310 , and the other end of toggle switch  310  is connected to row decode  19 . The other end of diode  314  is connected to one of the terminals of toggle switch  318 , and the other end of toggle switch  318  is connected to row decode  19 .  
         [0024]    One of the inputs of AND gate  302  is connected to column decode  20 , and the other input to AND gate  302  is connected to one of the ends of resistor  323 , one of the ends of diode  307  and one of the ends of diode  315 . The other end of resistor  323  is connected to ground. The other end of diode  307  is connected to one of the terminals of toggle switch  311 , and the other end of toggle switch  311  is connected to row decode  19 . The other end of diode  315  is connected to one of the terminals of toggle switch  319 , and the other end of toggle switch  319  is connected to row decode  19 .  
         [0025]    One of the inputs of AND gate  303  is connected to column decode  20 , and the other input to AND gate  303  is connected to one of the ends of resistor  324 , one of the ends of diode  308  and one of the ends of diode  316 . The other end of resistor  324  is connected to ground. The other end of diode  308  is connected to one of the terminals of toggle switch  312 , and the other end of toggle switch  312  is connected to row decode  19 . The other end of diode  316  is connected to one of the terminals of toggle switch  320 , and the other end of toggle switch  320  is connected to row decode  19 .  
         [0026]    One of the inputs of AND gate  304  is connected to column decode  20 , and the other input to AND gate  304  is connected to one of the ends of resistor  325 , one of the ends of diode  309  and one of the ends of diode  317 . The other end of resistor  325  is connected to ground. The other end of diode  309  is connected to one of the terminals of toggle switch  313 , and the other end of toggle switch  312  is connected to row decode  19 . The other end of diode  317  is connected to one of the terminals of toggle switch  321 , and the other end of toggle switch  321  is connected to row decode  19 .  
         [0027]    Column decode  20  and row decode  19  function by taking the selected output at logic one, i.e., a high level and keeping all the other outputs at logic zero, i.e., a low level. The output of AND gates  301 - 304  are connected to the input of OR gate  305 , and the output of OR gate  305  is data that is connected to the input of modulation circuit  17 . If switches  310 ,  311 ,  312  and  313 , respectively, remain open, AND gates  301 - 304 , respectively, will have a “zero” output. If switches  310 ,  311 ,  312  and  313 , respectively, are closed, AND gates  301 - 304 , respectively, will have a “one” output. The output of AND gates  301 - 304 , respectively, will be read when switches  318 - 321 , respectively, are closed.  
         [0028]    [0028]FIG. 3 is a drawing showing sensor circuit  25  of FIG. 2A in greater detail. The negative input of comparator  41  is connected to line  29 , and the positive input of comparator  41  is connected to line  38 . Comparator  41  may be a LM339N comparator. One end of line  38  is connected to a 2-3 volt reference voltage, and the other end of line  38  is connected to one of the ends of resistor  39 . The other end of resistor  39  is connected to the positive input of comparator  41  and one of the ends of resistor  40 . The other end of resistor  40  is connected to the input of NAND gate  42 , the output of comparator  41  and one of the ends of resistor  43 . The other end of resistor  43  is connected to a source voltage to act as a pull up resistor. The other input to NAND gate  42  is enable output  33 . The output of gate  42  is data output  34 . Resistor  39  may be 47,000 ohms, and resistor  40  may be 470,000 ohms. Resistor  43  may be 1,000 ohms. Comparator  41  has a positive feedback to provide a small amount of hysteresis  
         [0029]    Sensor circuit  25  is a differential circuit that accommodates variations in the conductivity of the conductive material. The conductive material may be used as a voltage divider to produce V ref  on line  38  under the same conditions experienced by conductive material. It will be obvious to one skilled in the art that sensor circuit  25  may replace switches  310 - 313  and  318 - 321  of FIG. 2B.  
         [0030]    [0030]FIG. 4 is a seller-furnished form to be completed by a buyer returning goods to a seller. RFID circuit  10  is attached to paper  50  by means of a conductive adhesive such as an anisotropic adhesive (not shown). The seller places a returned goods identification number  51  on the form to identify the buyer by writing the invoice number for the purchased goods on paper  50  in a manner that number  51  may be read by a RFID reader. Graphite contacts  52 ,  53 ,  54  and  55  and lines  56 ,  57 ,  58 ,  59  and  60  are printed on standard bond paper, standard photocopier paper, standard computer paper, etc., by a standard computer printer like the model Desk Jet 880C printer manufactured by Hewlett Packard using a Hewlett Packard  45  black ink cartridge.  
         [0031]    If the buyer decides to return a shirt to the seller, the buyer uses a graphite pencil, i.e., number 2, HB, etc., or a Paper Mate® black ball point pen to fill in rectangle  61 . If the buyer decides to return pants to the seller, the buyer fills in rectangle  62  with a graphite pencil, and if the buyer decides to return shoes to the seller, the buyer fills in rectangle  63  with a graphite pencil. If the buyer changes his/her mind regarding the goods to be returned or makes a mistake in filling in one of the rectangles, the buyer could erase the penciled marking in the rectangle with a pencil eraser so that a RFID reader would only read what the buyer indicated on the finished form. The buyer would insert the finished form into a package (not shown) containing the returned goods, and the seller would be able to read the completed form When he/she receives the package with a RFID read without opening the package. The filling in of any of rectangles  61 - 63  or no rectangle  61 - 63  with a pencil will form a bar code that may be read by an optical scanner.  
         [0032]    [0032]FIG. 5 is a drawing showing how a identification device, i.e., document, personal identification card, property identification device, file identification device, prescription identification device, book identification device etc. has markings to enable a RFID modified circuit to identify the document. A plurality of conductive graphite markings  355  is printed on document  353  that contains information. Markings  355  are printed in a manner that they will represent a code that identifies document  353 . When label  326  is placed over markings  355  and the appropriate contacts on label  326  (described in FIG. 6) are touched the code represented by marking  355  with be associated with document  353 . It will be obvious to one skilled in the art that document  353  may also be a personal identification card, property identification pass, file identification device, prescription identification label, book identification device etc.  
         [0033]    [0033]FIG. 6 is a drawing showing circuit  325  of FIG. 5 in greater detail. Circuit  325  is essentially the same circuit shown as circuit  10  of FIG. 1 with circuit  340  replacing memory array  21  of FIG. 1. One of the inputs of AND gate  341  is connected to column decode  20 , and the other input to AND gate  341  is connected to one of the ends of resistor  349  and one of the ends of diode  346 . The other end of diode  346  is connected to one of the ends of graphite contact  328 . The other end of resistor  349  is connected to ground. The other end of contact  328  is connected to row decode  19 .  
         [0034]    One of the inputs of AND gate  342  is connected to column decode  20 , and the other input to AND gate  342  is connected to one of the ends of resistor  350  and one of the ends of diode  347 . The other end of diode  347  is connected to one of the ends of graphite contact  329 . The other end of resistor  350  is connected to ground. The other end of contact  329  is connected to row decode  19 .  
         [0035]    One of the inputs of AND gate  343  is connected to column decode  20 , and the other input to AND gate  343  is connected to one of the ends of resistor  351  and one of the ends of diode  348 . The other end of diode  348  is connected to one of the ends of graphite contact  330 . The other end of resistor  351  is connected to ground. The other end of contact  330  is connected to row decode  19 .  
         [0036]    The output of AND gates  341 ,  342  and  343  is connected to the input of OR gate  352 , and the output of OR gate  352  is data that is connected to the input of modulation circuit  17 . If contacts  328 ,  329  and  330  are not touched, they will remain open, AND gates  341 - 343 , respectively, will have a “zero” output. If contacts  328 ,  329  and  330  are touched, they will be closed, respectively, and when column decode  20  provides a “one” output to one of AND gates  341 ,  342  and  343 , that AND gate that received an input from column decode  20  and was touched will have a “one” output. AND gates  341 ,  342  and  343 , supply their outputs to the inputs of OR gate  352  which provides its output to the input of modulation circuit  17 . This causes modulation circuit  17  to transmit a “one” or a “zero” out of RFID circuit  10  in accordance with the output of AND gates  341 ,  342  and  343 .  
         [0037]    It would be obvious to one skilled in the art that the output of circuit  340  may be combined with the output of a read only memory device in which a unique number is stored. Thus, when RFID circuit  10  is read the unique number is read along with the status of contacts  328 ,  329  and  330 .  
         [0038]    The above specification describes a new and improved circuit and RFID type circuit used in personal identification and document identification systems that uses printed lines to perform the function of wires so that information may be modified in the RFID type circuit by having an individual connect different printed lines by drawing a penciled line between the printed lines. It is realized that the above description may indicate to those skilled in the art additional ways in which the principles of this invention may be used without departing from the spirit. Therefore, it is intended that this invention be limited only by the scope of the appended claims.