Abstract:
An identification device formed from a band of material and a non-reusable tamper-resistant fastening arranged to join opposite end regions of the band. A Radio Frequency Identification (RFID) transponder is disposed in the band. The transponder includes and RFID circuit, such as may be formed on an integrated circuit (IC) chip, and an antenna. In the present invention, the tamper-resistant fastening serves additional functions beyond securing the opposite end regions of the band together. Namely, the fastening can be made of a conductive material and designed to create electrical continuity between multiple conductors to enable or disable certain circuit functionality. In one variation, this continuity allows the excess tail portion of the wristband to be cut without disrupting circuit functionality. In another variation, the fastening mechanism is designed to crimp conductors together. In yet another embodiment, the RFID circuit itself is wholly or partially formed within the fastening mechanism to better protect and support the circuit, as well as to make it more difficult to defeat the tamper-resistant functionality of the device.

Description:
RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. application Ser. No. 11/291,095, filed Nov. 29, 2005. The entire teachings of the above application is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a non-reusable identification device that may be used to identify persons or articles. 
       BACKGROUND OF THE INVENTION 
       [0003]    Disposable bracelets have long been used for such things as identification, access control, age verification, among other purposes. Such bracelets have typically been made from materials such as polyester, paper, or vinyl. The physical presence of a bracelet of particular color or design is traditionally used as its identifier. For example, such bracelets have been used in water parks and theme parks to quickly and uniquely identify patrons who have already paid for admission, or to control access to restricted areas. A patron of legal drinking age could obtain a bracelet to indicate that the patron is of legal age, granting the patron access to restricted areas such as beer sales areas. 
         [0004]    In recent years, such bracelets have been augmented with Radio Frequency Identification (RFID) technology. RFID extends the usefulness of such bracelets, as they can each be programmed with a unique code that quickly and easily identifies the wearer. RFID also adds new functionality to such bracelets. As one example, they can be used to locate the wearer. Thus, with the installation of appropriate radio location equipment, a lost child wearing an RFID bracelet can be easily located or prevented from leaving an amusement park unless accompanied by an authorized adult. 
         [0005]    RFID bracelets are also used to allow the purchase of items without the exchange of currency or need for a credit/debit card, or to allow secure communication and monetary exchange among patrons (for example, a parent may authorize credit of funds to a child to allow a purchase up to a preselected amount). Upon entering a park or other venue, a patron can request that the bracelet issued to the patron or the patron&#39;s family members be credited for purchases up to a preselected amount. Purchases up to the preselected amount can then be made using the bracelet instead of using cash or credit/debit cards. The bracelet can also be coded so that a wearer would be prevented from making certain purchases, or from making a single purchase above a chosen limit, so that children, for example, are encouraged to spend their allotted funds wisely. 
         [0006]    RFID bracelets of the type described above are most often made to be disposable, so that they are inexpensive to produce and easy to use. However, such bracelets are susceptible to misuse and unauthorized use. Some bracelets are easy to remove, yet still function after removal. A bracelet that still functions after it has been removed provides the opportunity for patrons to exchange bracelets. This could provide patrons with the opportunity to give access to a restricted area to an unauthorized patron. A patron issued an “adult” bracelet that allows access to beer sales, for example, could remove and give or sell that bracelet to a patron not of legal drinking age. As another example, a thoughtlessly discarded bracelet that still has funds credited to it could be retrieved and used by an unauthorized individual to purchase goods or services using someone else&#39;s account. 
         [0007]    A bracelet that is rendered non-functional after removal destroys its value for transfer to another patron, and would safeguard against unauthorized use of bracelets. 
         [0008]    A number of mechanical measures have been taken to prevent such bracelets from being transferred. One approach is a single-use locking button mechanism found on some plastic bracelets. An example of this approach is found in U.S. Pat. No. 5,973,600. Also known are adhesive locking mechanisms with slits that prevent the wearer from peeling the adhesive back and reattaching it. An example of that approach is found in U.S. Pat. No. 6,474,557. 
         [0009]    Those mechanisms render tampering with the lock or adhesive obvious to a visual inspection of the bracelet and, in most cases, render the bracelet unwearable after removal. However, tampering with the band portion of the bracelet is not prevented by those mechanisms. It is still possible for the bracelet to be cut or torn, and reattached with a simple piece of transparent tape or glue. To detect this sort of tampering, the person checking the bracelet would need to either make a full visual inspection of the bracelet or tug very firmly on the bracelet. This is slow, inconvenient, and impractical, especially when large numbers of people require identification. Furthermore, such a visual inspection is subject to human error, the most obvious being the failure of the bracelet checker to perform adequate inspection. 
         [0010]    The use of RFID technologies has thus made the process of identifying the bracelet wearer faster and more secure, resulting in an increased use of bracelets for identification purposes and for facilitating transactions. However, this can lead to complacency among those responsible for inspecting bracelets, and has a tendency to reduce the likelihood that the person checking the bracelet wearer will perform an adequate visual or physical inspection. 
         [0011]    Special electronic bracelets that prevent transferability for ensuring that hospital patients or prisoners remain within a given proximity of their quarters are known. However, such designs are prohibitively bulky, expensive, and overly complex for use in high-volume applications with short-term use. For example, U.S. Pat. Nos. 5,471,197 and 5,374,921 disclose the use of fiber optics to ensure that the bracelet is not removed. U.S. Pat. No. 6,144,303 describes a capacitive coupling between the bracelet and the wearer&#39;s skin. When the capacitance changes, indicating bracelet removal, an alarm is tripped. But the methods and devices disclosed in those patents are unnecessarily complex and prohibitively expensive for disposable use. 
         [0012]    U.S. Pat. Nos. 4,973,944 and 4,980,671 describe bracelets with DC current paths that run around the bracelet and form a closed circuit when the ends of the bracelet are brought together. This method involves complications when attempting to use it with conventional disposable bracelet designs, as it requires a large metal contact area to enable size adjustment of the bracelet. It also does not necessarily solve the problem of tampering because such bracelets are designed to activate an alarm when removed, not necessarily to prevent reattachment. The metal to metal contact surfaces could be easily reattached on a limb of a different user. 
         [0013]    Certain prior art disposable identification bands have been made tamper resistant by including a disabling wire in the band. For example, a co-pending U.S. patent application Ser. No. 10/400,049 on Mar. 26, 2003 by Girvin, J., and Lerch, J., entitled “Non-Reusable Identification Device”, assigned to Proximities, Inc., the assignee of the present application, a disabling wire is run along the band and is arranged to disable an RFID transponder if the wire is cut. 
       SUMMARY OF THE INVENTION 
       [0014]    The present invention is an identification device formed from a band of material and a non-reusable tamper-resistant fastening arranged to join opposite end regions of the band. In one preferred embodiment, a Radio Frequency Identification (RFID) transponder is disposed in the band. The transponder includes an RFID circuit, such as may be formed on an integrated circuit (IC) made of silicon or organic semiconductors, and an antenna. Circuitry in the transponder is arranged such that any cut, tear, or stretching of the band causes the RFID transponder to disable. This is typically achieved by running a conductor, referred to as a disabling wire, along substantially the entire length of the band. 
         [0015]    The fastening mechanism is coupled to the RFID transponder such that the RFID transponder does not function when the fastening is disengaged. This is typically achieved by providing a conductive path through the fastening mechanism, such that engaging the fastener provides a path for current to flow that did not previously exist. However, alternate techniques can be used. For example, the engagement of the fastener could introduce a capacitance required for the circuit to operate. 
         [0016]    The fastening may be constructed in the same fashion as one of many known one-way, non-reusable fasteners. Preferably, the fastening mechanism utilizes a barbed peg and mating hole, such as are commonly seen in disposable plastic bracelets made of Vinyl or Polyester. 
         [0017]    The fastening mechanism is preferably, though not necessarily, comprised of an injection molded, hard plastic, such as Nylon. The conductor may be embedded in the fastening at the time of injection molding or inserted afterwards. The conductor is typically fragile so as to make repair of a broken trace more difficult. Alternatively, the fastening itself can be made of metal or some other suitable conductor. 
         [0018]    In one specific implementation, the fastening becomes electrically coupled to the disabling wire at whichever point in the band the fastening is engaged, thereby shorting out the remainder of the disabling wire&#39;s path. In this embodiment, the disabling wire may be cut at any point beyond where the fastening is engaged without disrupting RFID functionality. This allows the wearer of the band to trim excess band material at the end of the band, such as with a pair of scissors or the like. The removal of excess band material is typically done with disposable plastic bands that utilize this sort of fastening mechanism, and the ability to do the same with a secure RFID wristband improves its acceptability to the user. 
         [0019]    In an alternative embodiment, the RFID circuit itself is embedded into the fastening mechanism. This prevents an individual from enabling the RFID transponder to function by creating an electrically continuous path between two of the provided contact points for the fastener, because this action would short circuit the RFID circuit. This increases the security of the wristband to attempts to improperly enable the RFID transponder. 
         [0020]    An electrical connection between the fastener and the transponder can be established in a number of different manners, each of which ensures that electrical continuity is broken when the fastening is disengaged. For example, the fastening mechanism may be arranged to make electrical contact with the RFID transponder at the time of manufacture. In the former case, the electrical contact can be made with solder or a conductive paste. In this instance, an electrically conductive path is typically created through the fastening only after the fastening is closed. 
         [0021]    The fastening mechanism may alternatively make contact with the transponder at the time of fastening. For example, the fastening may serve a crimping function and in that manner make contact with the transponder once attached to the band. Pressure contact could alternatively be used to produce electrical contact. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a bottom top view of a disabling RFID wristband according to the prior art. 
           [0023]      FIG. 2  is a top plan view of a wristband with a conductive snap closure mechanism as has been illustrated in prior art. 
           [0024]      FIG. 3  is a top plan view of a wristband according to the present invention, wherein the conductive snap makes contact with the disabling wire. 
           [0025]      FIG. 4  is an exploded view of a conductive snap designed to connect two formerly disconnected portions on a bracelet wherever the snap is affixed. 
           [0026]      FIG. 5  is a two-piece conductive snap where the conductive path becomes formed between the two pieces when they are joined. 
           [0027]      FIG. 6  is an exploded view of a conductive snap with the RFID circuit embedded within for increased stability and security. 
           [0028]      FIG. 7  is an exploded view of a crimping snap closure mechanism. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    A description of preferred embodiments of the invention follows. 
         [0030]      FIG. 1  is a general illustration of a disabling Radio Frequency Identification (RFID) bracelet  10 , as known in the art, in the form of elongated band  12  with opposite ends  14 ,  16  that can be brought together and fastened to form a closed loop. Bracelet  10  comprises a mechanical non-reusable tamper-resistant locking mechanism  18  to fasten the opposite ends  14 ,  16  together and to prevent the user from attempting to open the locking mechanism  18  to remove the bracelet  10  without rendering those tampering efforts visually obvious. Locking mechanism  18  comprises a barbed peg  20  and a locking hole  21  in flap  28  at one end of said band and at least one adjustment opening or adjustment hole  24  at the opposite end of said band. Adjustment holes  24  can be used to adjust the bracelet  10  to conform to body parts of different circumferences. When ends  14 ,  16  are brought together, the barbed peg  20  is arranged to pass through a selected hole  24  as required for a snug fit. The flap  28  is then folded along imaginary line  26  and barbed peg  20  is then passed through locking hole  21 . Peg  20  is shaped to resist removal from said locking hole  21  without also destroying the locking mechanism  18  and rendering it incapable of being refastened. Alternatively, or in addition, adjustment holes  24  can be designed to replace or supplement locking hole  21  by configuring them in such a way that attempts to remove the bracelet from the barbed peg  20  would also destroy the hole  24 , thereby disabling the bracelet and rendering it incapable of being refastened. 
         [0031]    Bracelet  10  also includes a transponder  32 . Transponder  32  contains an antenna  30  and an RFID integrated circuit (IC) chip  22 . The transponder  32  responds to an RF interrogation signal and in response emits an RF signal representative of information pre-stored or pre-programmed into RFID chip  22 . For example, the information could include the date the bracelet  10  is issued, the date the bracelet expires and will no longer be usable for access, the age status of the wearer, and whether the bracelet can be used for purchasing goods or services. Any other desired information, depending on the context in which the bracelet is to be used, may be pre-stored or pre-programmed in the transponder. The signal may also be used to access information stored in a database. 
         [0032]    The transponder  32  derives its power, in known fashion, from its antenna  30 . In the preferred embodiment, the antenna  30  has the form of a continuous electrically conductive coil. One or more tamper wires  34  extend away from the area occupied by the transponder  32 . The tamper wires  34  form an electrically conductive path, from antenna  30  out to end  16  and back to antenna  30 , along substantially the entire length of the band  12  of bracelet  10 . As will be explained in detail below, the tamper wires  34  are arranged to connect the components of transponder  32  and/or form portions of the components themselves, such that wires  34  must remain intact for the transponder  32  to operate. 
         [0033]    In one embodiment, one or more of the wires  34  may function as part of antenna  30 . In such an embodiment, consideration should be given to the distance between the sections of the loop antenna and wires  34  in order to minimize inductance that can lead to possible interference with the operation of the other components of transponder  32 . 
         [0034]    Wires  34  are preferably, but not necessarily, made from printed conductive ink that is robust enough to withstand normal handling but fragile enough that it will be broken if a user attempts to remove the bracelet. Alternatively, wires  34  may be a thin wire such as copper wire, a thin foil, or other suitable electrically conductive material that will form an electrically continuous path but will break as a result of tampering. Forming wires  34  with frangible zones, where stresses from tampering attempts are most likely to occur, may facilitate breakage of the conductor. Of course, if the user attempts to remove the bracelet  10  with a cutting implement, the conductor forming wires  34  will also be severed as band  12  is severed. 
         [0035]      FIG. 2  illustrates a design that makes use of a conductive snap circuit closure according to the prior art. The band  200  comprises a substrate structure  201 , a circuit  202 , a fastener with parts  203  and  204 , adjusting holes  205 , and conductors  206  and  207 , which connect the circuit  202  to fastener parts  203  and  204 , respectively. The fastening of the band  200  enables circuit functions within circuit  202 . If desired, the opening of the fastener disables functions within the circuit  202 . 
         [0036]    When the fastener closes, the parts  203  and  204  of the fastener come into contact, which creates a conductive path between conductors  206  and  207 , thereby enabling functions in circuit  202 . The conductors  206  and  207  may each comprise two or more separate electrical conductors that are connected to the circuit  202 ; the conductors  206 ,  207  further may comprise one or more of conductive wire or fiber, conductive foil, meltable conductor, or a printed conductor. In communication with the conductors is a fastener comprising one or more of a conductive adhesive, a conductive closure mechanism, a magnetic closure mechanism, a conductive rivet or staple, a crimped attachment, or a heat-created bond in proximity to the conductors. 
         [0037]      FIG. 3  illustrates a principal concept of the present invention. Bracelet  300  contains a transponder  32 , which is comprised of an antenna  30  and an RFID circuit  22 . Bracelet  300  includes a band section  400 . Antenna  30  is coupled to conductive wire  34  such that current will flow through conductive wire  34  in the path illustrated by loop  330  when transponder  32  is functioning. Conductive wire  34  is disposed on, and extends along, band section  400 , and contains a top conductor  35  and a bottom conductor  36 , which are joined at node  37 . If a discontinuity becomes present in conductive wire  34 , then transponder  32  will become disabled. Hence, conductive wire  34  is sometimes referred to as a disabling wire. 
         [0038]    Bracelet  300  also contains a conductive snap closure  320 , which is comprised of peg  318  and receiving hole  322 . Bracelet  300  is affixed to a wearer&#39;s wrist, ankle, or the like by inserting peg  318  into hole  322  through one of the adjustment holes  24  selected to create a snug fit around the wrist, ankle, or the like. The conductive snap  320  is designed such that when it is closed through an adjustment hole  24 , opposing disabling wire conductors  35 ,  36  become electrically connected through snap  320 . 
         [0039]    For example, if conductive snap  320  is closed through adjustment hole  24 - 1 , node  301  on top conductor  35  will become directly connected to node  302  on bottom conductor  36  through conductive snap  320 , thus allowing current to flow in the path illustrated by loop  340 . As such, a cut can now be made across the bracelet as indicated by dotted line  303  without disabling the circuit function. This enables the wearer to remove undesired excess band portion  380  without disrupting circuit function. This is helpful because excess band portion  380  can at times be irritating, uncomfortable, and interfere with daily free movement and activity. Excess band portion or slack is typically trimmed off of non-RFID bands that utilize plastic snap fasteners when they are worn. 
         [0040]      FIGS. 4 through 7  illustrate several conductive snap concepts that can be utilized in the present invention. Shown in  FIG. 4  is a conductive snap  320 , acting as the fastening element, comprised of two elements; a peg  318  and a mating hole  322 . Hole  322  is formed with a receiving housing  324  having an opening  326  for receiving peg  318  therethrough. A conductive ring  410  is exposed around the circumference of opening  326  such that it may make electrical contact with certain portions of the bracelet, such as band section  400 . For example, when conductive snap  320  is closed through an adjustment hole  24  by inserting and locking peg piece  318  through adjustment hole  24  and into mating hole housing  324 , conductive ring  410  comes into contact with wire conductors  35  and  36 . As such, conductors  35  and  36  become electrically connected through conductive ring  410 . In other words, current is able to flow in the direction indicated by loop  415 . 
         [0041]    Peg  318  also contains a raised section  420 . When snap  320  is engaged by inserting peg  318  into mating hole  322 , raised circular section  420  comes in very close proximity to conductive ring  410 . When a thin membrane, such as a portion of the bracelet, is between the peg  318  and hole  322 , raised section  420  applies firm pressure to the thin membrane to assist in creating a firm electrical contact between wire conductors  35  and  36  and ring  410  completing the transponder circuit while shorting the downstream loop. 
         [0042]      FIG. 5  shows an alternate conductive snap  320 ′ closure concept. In this case, wire  501  is electrically connected to peg  318 ′ at the time of bracelet manufacturing, as is wire  502  connected to mating hole housing  324 ′. Peg  318 ′ includes a conductive head  426  and conductive circular section  424  conductively coupled to wire  501 . Housing  324 ′ includes a secondary conductive ring  328  formed within housing  324 ′. When peg  318 ′ is inserted into mating hole  322 ′, conductive head  426  and circular section  424  contact conductive rings  328 ,  410  establishing electrical continuity between peg  318 ′ and housing  324 ′, thus allowing current to flow between wires  501  and  502  as indicated by loop  430 . When the two pieces are not joined together, the circuit is open and current cannot flow in the direction indicated by loop  430 . In this way, circuit discontinuity can be created to ensure security in the situation when the single-use snap has been cut, pried apart, or the like. 
         [0043]      FIG. 6  shows an embodiment of the conductive snap  320 ″ in which the RFID circuit  22  is contained within the snap mechanism itself. This can be accomplished by creating a solder joint between RFID chip terminal  601  and conductive ring section  651  as well as a solder joint between terminal  602  and ring section  652  formed on circular section  420 ′. Subsequently the chip could be embedded within peg piece  318 ″ as it is being injection molded. Conductive ring sections  651  and  652  could then be connected to conductors  35  and  36  respectively at the time of bracelet manufacturing. This will produce the desired result of connecting conductors  35  and  36  through RFID chip  22 . Alternatively, optional non-conductive raised section  420 ′ may apply additional pressure to increase the integrity of the contact made between wires  403 ,  404  and ring sections  651 ,  652  respectively. 
         [0044]    The inclusion of RFID chip  22  inside of the snap closure mechanism has a few advantages. Placing the chip inside of the snap provides it extra protection from impact and stress. In addition, forming an electrical connection inside of the chip enables a solder-joint connection, which is stronger than a conductive adhesive connection such as is typically used for attaching circuits to thin membranes such as Vinyl and PET. 
         [0045]    Most importantly, locating the chip  22  within snap  320 ″ increases the tamper resilience of the overall design. The most straight-forward way to defeat most RFID wristband security measures is to create an electrical connection between two points with a conductor such as a piece of foil, a solder joint, or even a staple. This becomes particularly important when contact points are being provided for the conductive snap to make electrical connection to, since it facilitates this procedure. With the RFID circuit chip  22  contained inside of the snap closure  320 , shorting to the available contact points would short-circuit the chip, thereby rendering the RFID transponder disabled. 
         [0046]    In addition to including RFID chip  22  within snap closure  320 ″, RFID antenna  30  or a portion thereof could also be included within snap closure  320 ″. Alternatively, in another embodiment, a separate tamper detection element could be contained within the snap. Examples of such tamper detection elements include electronic article surveillance tags that may use RF technology, electromagnetic (EM) technology, or acousto-magnetic (AM) technology. This type of dual transponder security wristband, which separates the identification function from the security function, is described in detail in pending U.S. patent application Ser. No. 11/095,017 on Mar. 31, 2005 by Lerch, J., Girvin, J., and Norair, J. entitled “Identification Band with Regions Having Electro-Magnetically Detectable Regions”, assigned to Proximities, Inc., the assignee of the present application. 
         [0047]    The variations in circuitry contained within the snap closure mechanism that are illustrated in  FIGS. 4 through 6  are just a few examples of potential implementations of a conductive snap. For example, the conductive ring in  FIG. 4  could just as easily be formed on the peg  318 . Likewise, the method of inserting the RFID circuit chip inside of the snap closure mechanism as depicted in  FIG. 6  could just as easily be implemented in a design that creates current flow through both the peg  318 ′ and mating hole  322 ′, such as is illustrated in  FIG. 5 . 
         [0048]      FIG. 7  illustrates yet another alternative method for creating continuity between two nodes in a bracelet circuit with a snap attachment mechanism. Unlike the other embodiments, this method does not require electrical conduction to occur through or within the snap closure mechanism itself. Rather, snap  720  acts as a crimping tool for crimping circuit paths on different layers together. 
         [0049]    Specifically, snap closure mechanism  720  is comprised of a modified peg  718  and a modified mating hole  722 . Peg  718  has several crimping posts  700  extending from circular portion  724 . Hole housing  726  has several crimping posts  701  that are complementary to crimping posts  700 . When peg piece  718  is inserted into hole piece  722  through bracelet section  750 , conductor layers  703  and  704 , surrounding an adjustment hole  24 , as well as through substrate layer  710  are partially pierced and folded over by complementary crimping posts  700  and  701 . This piercing and folding action creates a crimped electrical contact between wires  730  and  731  in bracelet section  750 . As such, crimping snap pieces  718 ,  722  are capable of achieving the same outcomes as  FIG. 4  and  FIG. 5  without any conductive material in the snap closure mechanism. 
         [0050]    In this embodiment, snap closure pieces  718 ,  722  are preferably injection molded out of a hard plastic such as Nylon. Alternatively, metal teeth could be utilized to form part of crimping mechanism  700 / 701 . 
         [0051]    It should be understood now that we have explained but a few of the possible embodiments, and that other arrangements of loops and of shorting wires can be used to accomplish the objectives of the invention. 
         [0052]    While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.