Abstract:
The present invention is directed towards a novel procedure and system for making a security tag for an aluminum-pressed, cardboard container. The method employs a system of distancing the tag from the container and a method of calibrating the tag. The tag is then inserted into a specially designed cap and spaced a given distance from the container. The product is sealed and then sold to the consumer.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from provisional U.S. Patent Application No. 60/614,072, filed on Sep. 29, 2004 whose disclosure is incorporated by reference herein. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     “Not Applicable” 
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK 
     “Not Applicable” 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to security systems and devices for use with containers having some metallic portion to hold a security tag, e.g., an EAS tag, an RFID tag, etc., and more particularly, to devices for holding such a tag on the container such that an RF receiver is able to readily discern a return signal from the tag, to systems making use of such devices, and to methods of using such systems and calibrating such tags. 
     2. Description of Related Art 
     The prior art teaches various mechanisms of using security tags to secure a multitude of different products. Some examples of commonly known security tags are RF, AM and UHF tag, traditionally known as electronic article surveillance (EAS) tags. Other security tags, e.g., radio frequency identification (RFID) tags, make use of electronic chips. EAS, RFID and other types of electronic security tags can be and are used mounted or secured to many different products, e.g., books, pallets, containers, and electronics. Heretofore, products that are housed in containers or cans having metallic portions, e.g., containers or cans for baby foods and other foodstuffs, etc., have not been effectively tagged. 
     As will be appreciated by those skilled in the art, many containers for foods are made of plastic. However, plastic has inherent limitations for housing such products. For example, plastic may allow trace amounts of bacteria through it. Baby food manufacturers are particularly sensitive to the limitations of plastics as a container medium and consequentially, many such manufacturers make their containers or cans out of cardboard tubular midsection having a pressed, thin aluminum foil around the outside of the midsection as a means for preventing liquid leakage out of the container. Additionally, the lid and the base of the can or container are generally made of a thin aluminum sheet. A relatively thick, annular aluminum annular ring serves to join the lid to the cardboard midsection, a similar ring serves to join the base to the cardboard midsection. This arrangement provides an inexpensive, easily manufactured, waterproof container that can safely hold foodstuffs. However, such containers include so much metal that they cannot be effectively tagged with an EAS, RFID or other electromagnetic radiation based tag, since the metal of the container will interfere with the electromagnetic properties of the tag, e.g., the metal portion of the can will reduce the amplitude of the return signal from the tag. Moreover, the metallic portion of the container also tends acts as an antenna, thereby altering the frequency response of the tag. 
     Thus, a need exists for a device which will enable the effective tagging of containers that include substantial metallic portions, e.g., baby food containers, soup containers, etc. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with one aspect of this invention there is provided a device for attachment to a container having a metallic portion onto which a security tag, e.g., an EAS tag, an RFID tag, etc., is desired to be secured. The tag is capable of receiving a transmitted electromagnetic signal over the air from a transmitter, e.g., a transceiver, and for returning a desired discernable electromagnetic signal to a receiver, e.g., the transceiver. The device has a holding portion and is arranged to be secured to the container, whereupon the holding portion is located over or under the metallic portion of the container. The holding portion of the device is arranged to hold the tag in place over or under, but spaced from, the metallic portion of the container by a distance sufficient to ensure that the metallic portion of the container does not preclude proper operation of the tag with the receiver. 
     In accordance with another aspect of this invention there is provided a security device for attachment to a container. The security device comprising a security tag, e.g., an EAS tag, an RFID tag, etc., and a tag holder for mounting the tag on the container. The container has a metallic portion onto which the security tag is desired to be secured, said security tag being capable of receiving a transmitted electromagnetic signal over the air from a transmitter, e.g., transceiver, and for returning a desired discernable electromagnetic signal to a receiver, e.g., the transceiver. The tag holder includes a holding portion for holding the tag thereon. The tag holder is arranged to be secured to the container over the metallic portion of the container so that the holding portion holds the tag in place over, but spaced from, the metallic portion of the container by a distance sufficient to ensure that the metallic portion of the container does not preclude proper operation of the tag with the receiver. 
     In accordance with still another aspect of this invention there is provided the combination of a conventional container, e.g., a baby food container, a security tag, e.g., an EAS tag, an RFID tag, etc., and a tag holder. The container has a metallic portion onto which the security tag is desired to be secured. The security tag is capable of receiving a transmitted electromagnetic signal over the air from a transmitter, e.g., a transceiver, and for returning a desired discernable electromagnetic signal to a receiver, e.g., the transceiver. The tag holder includes a holding portion on which the tag is secured. The tag holder is arranged to be secured to the container so that the holding portion holds the tag in place over or under, but spaced from, the metallic portion of the container by a distance sufficient to ensure that the metallic portion of the container does not preclude proper operation of said tag with the receiver. 
     In accordance with still another aspect of this invention there is provided a system for monitoring the presence of a container having a metallic portion. The system comprises a security tag, e.g., an EAS tag, an RFID tag, etc., a tag holder and a transmitter and a receiver, e.g., a transceiver. The tag is capable of receiving a transmitted electromagnetic signal over the air from the transmitter and for returning a desired discernable electromagnetic signal to the receiver. The tag holder includes a holding portion and is adapted to be secured to the container so that the holding portion holds the security tag on the container over or under, but spaced from, the metallic portion of the container by a distance sufficient to ensure that the metallic portion of the container does not interfere with the proper operation of the tag with the receiver. 
     In accordance with still another aspect of this invention there is provided a method of tagging a container having a metallic portion with a security tag, e.g., an EAS tag, an RFID tag, etc. The method basically entails providing a security tag capable of receiving a transmitted electromagnetic signal over the air from a transmitter and returning a desired discernable electromagnetic signal to a receiver. The tag is disposed and secured to the container over or under, but spaced from, the metallic portion of the container by a distance sufficient to ensure that the metallic portion of the container does not preclude proper operation of the tag with the receiver. 
     In accordance with still another aspect of this invention there is provided a method of calibrating a security tag, e.g., an EAS tag, a RFID tag, etc., that is arranged for use with a container having a metallic portion. The method entails providing a security tag capable of receiving a transmitted electromagnetic signal over the air from a transmitter and for returning a discernable electromagnetic signal to a receiver when operating in free space. The tag is disposed over or under, but spaced from, the metallic portion of said container. An electromagnetic signal is transmitted to the, whereupon said tag provides a discernable return signal as a function of its location with respect to the metallic portion of the container. The frequency and magnitude of the return sign is determined and, if necessary, at least one electrical parameter of the tag is modified, so that the return signal provided by the tag is within a desired frequency range, e.g., 13.56 MHz, 8.2 MHz+/−0.5 MHz, etc., and of a minimum amplitude. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
       The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein: 
         FIG. 1  is an isometric view of one exemplary, prior art, type of container for which the subject invention is of particular utility; 
         FIG. 2  is a view, like that of  FIG. 1 , but showing the bottom of the prior art container of  FIG. 1 ; 
         FIG. 3  is an isometric view of one exemplary EAS tag constructed in accordance with one aspect of this invention and which is arranged for securement to either the top or the bottom of the container shown in  FIGS. 1 and 2 ; 
         FIG. 4A  is a side elevation view, partially in section, of one exemplary embodiment of a holding device constructed in accordance with one aspect of this invention shown holding a tag like that of  FIG. 3  on the top portion of the container of  FIG. 1 ; 
         FIG. 4B  is an exploded view, partially in section, of the embodiment of the holding device shown in  FIG. 4A ; 
         FIG. 5A  is a side elevation view, partially in section, of another exemplary embodiment of a holding device constructed in accordance with one aspect of this invention shown holding a tag like that of  FIG. 3  on the top portion of the container of  FIG. 1 ; 
         FIG. 5B  is an exploded view, partially in section, of the embodiment of the holding device shown in  FIG. 5A ; 
         FIG. 6A  is a side elevation view, partially in section, of still another exemplary embodiment of a holding device constructed in accordance with one aspect of this invention shown holding a tag like that of  FIG. 3  on the top portion of the container of  FIG. 1 ; 
         FIG. 6B  is an exploded view, partially in section, of the embodiment of the holding device shown in  FIG. 6A ; 
         FIG. 7A  is a side elevation view, partially in section, of still another exemplary embodiment of a holding device constructed in accordance with one aspect of this invention shown holding a tag like that of  FIG. 3  on the top portion of the container of  FIG. 1 ; 
         FIG. 7B  is an exploded view, partially in section, of the embodiment of the holding device shown in  FIG. 7A ; 
         FIG. 8  is an exploded side elevation view, of still another exemplary embodiment of a holding device constructed in accordance with one aspect of this invention shown holding a tag like that of  FIG. 3  and which is adapted to be mounted on the top portion of the container of  FIG. 1 ; and 
         FIG. 9  is a side elevation view, partially in section, showing the embodiment of the holding device of  FIG. 8  and the tag of  FIG. 3  ready to be mounted on the top portion of the container of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now in greater detail to the figures, there is shown in  FIG. 4A  one exemplary embodiment of a holding device  20  constructed in accordance with one aspect of this invention for holding a security, e.g., RF, RFID, etc., tag  200  ( FIG. 3 ) on a conventional container or can  10  having at least one metallic portion. The device  20  of  FIG. 4A , as well as the other exemplary embodiments of other holding devices shown and described herein and other holding devices constructed in accordance with the teachings of this invention, enables a security tag to be mounted on the container adjacent the metallic portion of the container to operate, e.g., respond to an interrogation signal, in a manner similar to a tag on a non-metallic container. Accordingly, a metallic container making use of this invention can be protected from theft, tracked and/or identified as has been accomplished with tags on non-metallic containers. 
     It should be pointed out at this juncture that the container or can  10  can be of any type of construction, such as a conventional can shown in  FIGS. 1 and 2 , or any other type of hollow container having at least one wall portion formed of metal. Depending upon the size of the container and the amount of metal that makes it up, the tag can be of conventional construction, e.g., a conventionally constructed EAS tag, or can be a larger area, e.g., circular shaped, tag, constructed in accordance with another aspect of this invention. One such tag is the exemplary tag  200  shown in  FIG. 3 . 
     Before describing the details of the various holding devices of this invention, a brief description of the can  10  and of the tag  200  is in order. To that end, as can be seen in  FIGS. 1 and 2  the container or can  10  basically comprises cylindrical mid-section or side wall  10 A, a top wall  10 B, a bottom wall  10 C ( FIG. 2 ), a top bead  10 D extending about the periphery of the side wall  10 A at the interface of the side wall and the top wall and a bottom bead  10 E extending about the periphery of the side wall at the interface of the side wall and the bottom wall. The side wall is a tubular member that may be formed of cardboard with a metallic, e.g., aluminum, inner lining (not shown) or may be made up entirely of metal, e.g., aluminum. The top wall or lid  10 B is a generally planar member of circular profile and can be made up of any suitable material, e.g., aluminum. The bottom wall or base  10 C is of similar construction to the top wall  10 B, except that the top wall may be constructed, e.g., have a weaken or frangible line  10 F extending about its periphery, to be readily removed by pulling if off of the container to provide access to the contents of the container. To that end, the top wall or lid  10 B may include a conventional pull tab  12 . The beads  10 D and  10 E are of identical construction, e.g., each is formed of aluminum. The bead  10 D serves to fixedly secure the lid  10 B to the side wall  10 A. Similarly, the bead  10 E serves to fixedly secure the base  10 C to the side wall  10 A. It should be pointed out at this juncture that the metal portions of the container  10  can be formed of other metals than aluminum, if desired. 
     The exemplary tag  200  of this invention, will be described later. Suffice for now to state that it is similar in construction to activatable/deactivatable swept frequency EAS tags sold by Checkpoint Systems, Inc., of Thorofare, N.J., the assignee of this invention, except that it is somewhat larger in size and of circular profile to enable it to cover most of the area of either the lid  10 B or base  10 C of the container  10  when it is mounted thereon by a mounting device constructed in accordance with this invention, e.g., a device like device  20  of  FIG. 4A . In particular, in the exemplary embodiment shown in  FIG. 3  the security tag  200  has the same basic structure as that disclosed in FIG. 2 of U.S. Pat. No. 5,081,445 (the “&#39;445 patent”), which is assigned to Checkpoint Systems, Inc. and whose disclosure is incorporated by reference herein, with the following exceptions. The diameter of tag  200  is 3 inches to 4.5 inches, whereas the tag of the &#39;445 patent has a surface area of about 2.5 sq. in. Moreover, the tag  200  is circular in shape, whereas the tag of &#39;445 patent is square in shape. The circular shape of tag  200  has renders the tag more efficient per unit area than tags of square or rectangular profile. Thus, when the energy demands of the tag are high, and the space one can fit the tag into is small, a circular tag is preferable. Otherwise, a square or rectangular profile tag can be used in place of the circular tag. However, the surface area of the square or rectangular tag will need to be greater than the circular tag, for a given application. If the container is a different shape, e.g., the portion on which the tag is to be located, the largest circular tag that can be fitted into that shape is preferred. 
     As will be appreciated by those skilled in the art, by using the largest tag possible, one can reduce the effects that the metallic portion of the container has on signal returned to the receiver. However, in experimentation, using a 11.4 sq. in. tag provides useful signal power, though larger tags would be more powerful, but more expensive to manufacture. Additionally, the inductance and capacitance of circular tags are different as compared to square tags. 
     Turning now to  FIG. 3  the details of the exemplary tag  200  will now be considered. As can be seen, tag  200  basically comprises a pair of electrically conductive patterns or traces, to be described hereinafter, to form the electrical circuitry of the tag. In the exemplary embodiment of  FIG. 3 , the tag  200  is an EAS resonant tag in the form of a coil L and a pair of capacitors C 1  and C 2 , with the electrically conductive traces making up those electrical components. In particular, the tag  200  includes a first electrically conductive trace  202  and a second electrically conductive trace  204 . The traces are formed of any suitable electrically conductive material, e.g., aluminum. The first electrically conductive trace  202  is in the form of a spiral coil that is of constant width along its length except for its end portions  202 A and  202 B. The coil forms the inductor L. The end portion  202 A at the inner end of the coil  202  is of an enlarged, e.g., bulbous, area to form a first plate of a first capacitor, namely, capacitor C 1 . The end portion  202 B at the outer end of the coil  202  is also enlarged to form a first plate of a second capacitor, namely, capacitor C 2 . The second trace  204  is disposed over the first trace and is an elongated, generally linear, strip that is of constant width along its length except for its end portions  204 A and  204 B. The end portion  204 A at the inner end of the strip  204  is of an enlarged, e.g., bulbous, area to form the second plate of the first capacitor C 1 . The end portion  204 B at the outer end of the strip  204  is also of an enlarged area to form the second plate of the second capacitor C 2 . A dielectric layer  206 , such as a film of polyethylene, only a portion of which is shown, is interposed between the two electrically conductive traces  202  and  204 . The dielectric layer  206  serves as the dielectric between the plates of the first and second capacitors C 1  and C 2 , respectively. 
     As will be appreciated by those skilled in the art, the electrical properties of the resonant circuit created by the traces  202  and  204  can be adjusted by changing the geometry and/or the materials making up the traces and/or by changing the thickness and/or material(s) making up the dielectric film  206 . The adjustment of the electrical properties of the tag is important to enable the tag to be appropriately calibrated for use with a particular container construction and holding device constructions, as will be described in detail later. 
     The tag  200  may be mounted on a paper layer or some other substrate, such as substrate  208 , to facilitate its securement to a holding device constructed in accordance with this invention, or to the article to be tagged (if no holding device is necessary, e.g., if the container doesn&#39;t include any metallic portion over which the tag is to be placed). In order to facilitate the securement of the tag to the holding device or to the article itself the substrate  206  may include an adhesive (not shown) on it. 
     The tag  20  when mounted on the container  10  by means of a mounting device constructed in accordance with this invention is particularly suitable for use in a conventional EAS security system. For example conventional EAS equipment, e.g., an RF pedestal including a transceiver, can be used to generate a so-called swept RF signal within a desired bandwidth. The inductor/capacitor circuit of the tag  200  is resonant within that transmitted frequency band, e.g., at appoximately 8.2 MHz+/−0.5 MHz. The presence of a non-deactivated tag within the field of that transmitted RF signal distorts the signal and that distortion is detected by the receiver portion of the transceiver, which then produces an alarm. If however, the tag has been deactived, an alarm signal will not be produced when the tag is within the field. 
     Turning now again to  FIGS. 4A and 4B , the details of the construction and operation of one exemplary embodiment of a tag holding device  20  constructed in accordance with this invention will now be discussed. To that end it can be seen that the holding device  20  basically comprises a cap which is arranged to be secured to the container  10  over its lid or top wall  10 B. This is merely exemplary, since the cap could just as easily be secured over the base or bottom wall  10 C. 
     The cap basically comprises a disk-like member  22  and an ring-like insert  24 , each of which is preferably made of plastic or some other non-metal. The member  22  is in the form of a generally planar wall  26  of circular profile having a downwardly depending annular flange  28 . The inner surface of the flange  28  includes an internal helical thread  30 . The insert  24  is in the form of a ring having an upper annular portion  32  and a lower annular portion  34  The upper annular portion  32  has an outside diameter that is approximately equal to the inside diameter of the annular flange  28  and includes an external helical thread  36  for engagement with the internal helical thread  30 . The engagement of the threads  30  and  36  releasably secures the disk-like member  22  to the ring-like insert  24 . The lower annular portion  34  depends downward from the upper portion  32  and is of larger outside diameter than the outside diameter of the upper portion  32 . The inner surface of the lower annular portion  34  includes an annular recess  38  whose inside diameter is just slightly larger than the outside diameter of the upper or lower beads  10 D and  10 E, respectively, of the can  10 . The recess  38  is provided to enable the upper or lower bead of the can to be snap-fit therein to mount the assembled cap  22  on the can  10 . In order to facilitate that action, the bottom end of the lower annular portion  34  of the ring-like insert includes a projection or lip having a cam surface  40  extending inward radially. This projection is arranged to flex slightly to enable the bead of the can to slide over the cam surface  40  and into the contiguous recess  38 , thereby releasably locking the holding device (cap)  20  in place on the can. 
     When so mounted the undersurface  26 A of the holding device  20  will be spaced from the metallic lid of the can  10 . The undersurface  26 A thus can serve as the location for mounting the security tag, e.g., tag  200 , to space the tag from the metal of the lid  10 B (or the base  10 C, if the cap  20  is mounted over the base). By spacing the tag  200  away from the metal of the lid, the signal compromising effect of that metal is overcome. In particular, the spacing of the tag from the metal lid overcomes the signal amplitude attenuating effect of the metal of the lid. The amount of spacing between the tag and the metal lid or base can be determined empirically or otherwise to enable the tag when mounted on the can to provide a discernable return signal of a desired amplitude and within a desired frequency range to be readily read by the receiver of the security system. The manner of calibrating the tag for such operation will be described later. 
     The tag  20  can be held onto the undersurface  26 A of the holding device or cap  20  in various manners. In the embodiment shown in  FIGS. 4A and 4B  an adhesive is used. That adhesive may be in the form of a coating  210  on the substrate  208  of the tag  200 . 
     Since the holding device (cap)  20  is snap-fit on the container  10 , it may be readily removed by the user (purchaser) of the product to provide the user with access to the lid (or base, as the case may be) of the container. In particular, all that is required to provide such access is for the user to pull the cap  20  upward with respect to the can  10 , whereupon the bead  10 D will exit from the annular recess  38 , thereby freeing the cap from the can. The user can then open the can&#39;s lid  10 B by merely pulling on the pull tab  12 . 
     In order to deter the surreptitious removal of the holding device or cap  20  with the tag  200  therein from the container  10  while it is in the retail establishment and before it passes through the exit security system, a seal or wrap can be provided about the holding device and the container to hold the two together. To that end, as shown in  FIG. 4A  a wrap  42 , in the form of a heat shrinkable band, may be provided about the entire holding device/can combination or only about the holding device and a contiguous portion of the can. Moreover, the wrap need not be heat shrinkable. Other mechanisms for sealing the cap  20  onto the container are envisioned, such as using an adhesive seal, a paper seal, or using a cap integrally formed on the container. The last option is similar to the way milk containers are sealed. 
     In  FIGS. 7A and 7B  there is shown an alternative embodiment of a holding device or cap  120  constructed in accordance with this invention. The cap  120  is similar in most respects to the holding device  20 , except that it is a unitary structure that is not made up of a disk-like member and ring-like insert. Moreover, the holding device  120  makes use of a spacer, to be described later, that is located between the metal portion of the can  10  and the portion of the holding device  120  at which the security tag  200  is located. In the interest of brevity the common components of the holding devices  20  and  120  will be given the same reference numbers. Thus, as can be seen the holding device  120  basically comprises a integral member, preferably formed of plastic or some other suitable non-metal, and having a generally planar wall  126  of circular profile and a downwardly depending annular flange  128 . The inner surface of the annular flange  128  includes an annular recess  38  whose inside diameter is just slightly larger than the outside diameter of the upper or lower beads  10 D and  10 E, respectively, of the can  10 . The recess  38  is provided to enable the upper or lower bead of the can to be snap-fit therein to mount the assembled cap  120  on the can  10 . In order to facilitate that action, the bottom end of the lower annular portion  34  of the ring-like insert includes a projection having a cam surface  40  extending inward radially. This projection is arranged to flex slightly to enable the bead of the can to slide over its outer surface and into the contiguous recess, thereby releasably locking the holding device  120  in place on the can  10 . 
     The planar wall  126  includes an undersurface  126 A, which like the embodiment  20  serves as the location for mounting the security tag  200 , whereupon the tag of the holding device will be spaced from the metallic lid of the can  10 . Unlike the holding device, where air serves to fill the space between the tag and the metal portion of the can, a physical spacer element  102  is provided in the holding device  120  to sandwich the tag  200  between it and the undersurface  126 A of the cap  120 . The spacer  102  basically comprises a disk-like member formed of plastic or some other suitable non-metal. The outside diameter of the spacer is approximately equal to the inside diameter of the annular flange  128 , and the thickness of the spacer is such that its lower surface is flush with the upper edge of the annular recess  28  when the tag is sandwiched therebetween, as clearly shown in  FIG. 7A . The tag  200  can be held in place by an adhesive layer  210  as described earlier. Since the tag will be sandwiched between the spacer  102  and the undersurface  126  of the cap member the adhesive  210  may be omitted. 
     If desired, the holding device  120  may make use of a wrap  42  to hold it in place on the container to deter its removal from the container. 
     In  FIGS. 5A and 5B  there is shown another exemplary embodiment of a holding device  220  of this invention. The holding device  220  is perhaps the most preferred of the various embodiments since it is constructed to have a portion serving as a label for the container  10  to which the device  220  is secured. The device  220  includes various features common to the holding devices  20  and  120 . In the interest of brevity the common components of those devices will be given the same reference numbers. As can be seen the holding device or cap  220  basically comprises an integral member, preferably formed of plastic or some other suitable non-metal, and having a generally planar central wall  226  of circular profile, a downwardly depending annular flange  228  and an upwardly depending annular flange  230 . The inner surface of the downwardly depending annular flange  128  includes an annular recess  38  whose inside diameter is just slightly larger than the outside diameter of the upper or lower beads  10 D and  10 E, respectively, of the can  10 . The recess  38  is provided to enable the upper or lower bead of the can to be snap-fit therein to mount the assembled cap  220  on the can  10 . In order to facilitate that action, the bottom end of the lower annular portion  34  of the ring-like insert includes a projection having a cam surface  40  extending inward radially. This projection is arranged to flex slightly to enable the bead of the can to slide over its outer surface and into the contiguous recess, thereby releasably locking the holding device  220  in place on the can  10 . 
     The planar wall  226  includes a stepped circular shaped recess  232  in its top surface. The recess  232  includes a lower section  232 A and an upper section  232 B, The inside diameter of the upper section is larger than the inside diameter of the lower section to form an annular ledge  232 C. This surface serves to receive an annular disk-like member  234 , which can be used to form a label for the device/article to be tagged. The label  234  basically comprises a sheet of plastic, cardboard, paper or some other material which can bear indicia, e.g, text, graphics, etc., thereon. The outside diameter of the label  234  is slightly less than the inside diameter of the recess section  232 A so that its peripheral edge can rest on and be secured by means, e.g., an adhesive (not shown) to the top surface of the ledge  232 C. The undersurface of the label  234  serves as the location on which the tag  200  is mounted. To that end, the tag is secured to the undersurface of the label  234  by the adhesive  210 . The height of the recess section  232 B is selected to be at least equal to the thickness of the label  232 . Moreover, the height of the recess section  232 A is selected to be at least equal to the combined thickness of the tag  200  and the adhesive layer  210 . Accordingly, when the tag is secured onto the undersurface of the label  234  and the label is secured in the recess  232  of the cap member  220  the label fits flush within the cap as shown in  FIG. 5A , with the thickness of the planar wall  226  spacing the tag from the metal lid  10 B of the container. The adhesive securement of the label to the cap device  220  prevents the surreptitious removal of the tag. 
     If desired the holding device  220  may make use of a wrap  42  to hold the device in place on the container to deter removal of the device. 
     In  FIGS. 6A and 6B  there is shown another exemplary embodiment of a holding device or cap  320  constructed in accordance with this invention. The holding device  320  is similar in many respects to the holding device  220  in that it makes use of a label to serve as the means for holding the tag in place. Thus, in the interest of brevity the common components of the holding devices  220  and  320  will be give the same reference numbers. The holding device  320  basically comprises an integral member, preferably formed of plastic or some other suitable non-metal, and having a generally planar central wall  326  of circular profile, a downwardly depending annular flange  328  and an upwardly depending annular flange  330 . The inner surface of the downwardly depending annular flange  128  includes an annular recess  38  whose inside diameter is just slightly larger than the outside diameter of the upper or lower beads  10 D and  10 E, respectively, of the can  10 . The recess  38  is provided to enable the upper or lower bead of the can to be snap-fit therein to mount the assembled cap  320  on the can  10 . In order to facilitate that action, the bottom end of the lower annular portion  328  includes a projection having a cam surface  40  extending inward radially. This projection is arranged to flex slightly to enable the bead of the can to slide over its outer surface and into the contiguous recess, thereby releasably locking the holding device  220  in place on the can  10 . 
     The upper annular flange  330  includes a top surface  332  in which an annular recess  334  is located. A pair of opposed annular lips  336  extend towards each other on opposite sides of the recess  334  contiguous with the top surface  332 . The lips  336  are angled slightly downward to create a tapering entryway to the recess  334 . This entryway and recess serves as the means for securing a label to the cap device  320 , as will be described hereinafter. 
     The label basically comprises a disk-like member  338  of circular profile and which can bear indicia, e.g, text, graphics, etc., thereon. The undersurface of the label serves as the location for mounting the security tag  200  in the same manner as described earlier, e.g., via the use of the adhesive  210 . As also mentioned above the label is arranged to be secured to the cap device  320  via the recess  334 . To that end, an annular ridge  340  projects downward from the undersurface of the label member  338  closely adjacent the periphery thereof. The ridge in cross-section resembles an arrowhead. Accordingly, when the label  338  with the tag secured to its bottom surface as described above is placed over the cap device  320  it can be pressed downward to secure it to the cap device. In particular, the downward push causes the arrowhead portion of the label&#39;s ridge  338  to pass through the tapering entryway to the recess  334 , thereby causing the lips  336  to flex to enable the arrowhead portion of the ridge to pass therethrough into the recess. Once this has occurred the lips flex back to lock the arrowhead portion of the ridge within the recess. This action effectively secures the label  338  onto the cap device  320 , thereby preventing surreptitious removal of the tag  200 . 
     If desired the holding device  320  may make use of a wrap  42  to hold the device in place on the container to deter removal of the device. 
     In  FIG. 8  there is shown another exemplary embodiment of a holding device  420  constructed in accordance with this invention. The holding device  420  is similar in many respects to the holding device  120  in that it makes use of a unitary construction, but does not include a spacer element and includes alternative means for securing the tag  200  in place. Thus, in the interest of brevity the common components of the holding devices  120  and  420  will be give the same reference numbers. The holding device or cap  420  basically comprises an integral member, preferably formed of plastic or some other suitable non-metal, and having a generally planar central wall  426  of circular profile, a downwardly depending annular flange  428 , and an intermediate annular flange  430 . The intermediate flange extends radially inward from the inner surface of the downwardly depending annular flange  428 . The inner surface of the downwardly depending annular flange  428  includes an annular recess  38  located immediately below the intermediate flange  430 . The annular recess  28  has an inside diameter just slightly larger than the outside diameter of the upper or lower beads  10 D and  10 E, respectively, of the container  10  to enable it to receive either the top or bottom beads of the container to secure the holding device  420  on the container in the same manner as described earlier. 
     The tag  200  is arranged to be secured to the undersurface of the generally planar central wall  426  without the use of any adhesive. To that end an annular wall or ridge  432  projects downward from the undersurface of the central wall  426 . An annular recess  434  is located in the ridge  432  to enable the circular tag  200  to be snap-fit therein. In order to facilitate that action, the bottom end of the annular ridge  432  includes a projection having a cam surface  40  extending inward radially. This projection is arranged to flex slightly to enable the periphery of the circular tag  200  to slide over its cam surface and into the contiguous recess  434 , thereby locking the tag  200  in place in that recess under the central wall  426  of the cap  420 . 
     When the tag is so mounted and the holding device or cap  420  is mounted on the container  10  the tag  200  will be spaced from the metallic lid of the can  10 . 
     If desired the holding device  420  may make use of a wrap  42  to hold the device in place on the container to deter removal of the device. 
     In  FIG. 9  there is shown another exemplary embodiment of a holding device  520  constructed in accordance with this invention. The holding device  520  is similar in many respects to the holding device  420  except that it makes use of the adhesive securement of the tag to the device. Thus, in the interest of brevity the common components of the holding devices  420  and  520  will be given the same reference numbers. The holding device or cap  520  basically comprises an integral member, preferably formed of plastic or some other suitable non-metal, and having a generally planar central wall  426  of circular profile, a downwardly depending annular flange  428 , and an intermediate annular flange  430 . The intermediate flange extends radially inward from the inner surface of the downwardly depending annular flange  428 . The inner surface of the downwardly depending annular flange  428  includes an annular recess  38  located immediately below the intermediate flange  430 . The annular recess  28  has an inside diameter just slightly larger than the outside diameter of the upper or lower beads  10 D and  10 E, respectively, of the container  10  to enable it to receive either the top or bottom beads to secure the holding device  420  on the container in the same manner as described earlier. 
     As mentioned above, the tag  200  is arranged to be secured to the undersurface of the generally planar central wall  426  of the holding device  520  by use of an adhesive. To that end, the adhesive is preferably in the form of a coating  210  on the substrate  208  of the tag  200 . 
     If desired the holding device  520  may make use of a wrap  42  to hold the device in place on the container to deter removal of the holding device. 
     It should be pointed out at this juncture that a holding device or cap of this invention may not include the annular recess for securing it to a container. Thus, it is contemplated that other securing mechanisms could be used, such as grooves, adhesives, fasteners, or other devices. Moreover, while some embodiments merely space the tag from the metal portion of the container by air, other embodiments make use of a physical spacer element, essentially sandwiching the tag between the top of the cap and the spacer element. The spacer, like the cap itself, is preferably made of plastic for economic &amp; magnetic purposes as it is readily available and a dielectric. However, other materials may be substituted for plastic, as known in the art. 
     Calibration of the tag/holding device for use on a particular container is accomplished in the following general manner. In particular, the following utlines the general method steps for determining the necessary frequency that the tag needs to be designed at so that transceivers can receive the desired signal. For example, as is know, transceivers of EAS tags listen for a return signal at 8.2 MHz. Though the frequency of the tag will be different for each type of container, most of the tags have a return frequency set to 7.0 MHz. The inductance is 0.9:H and the capacitance is 521 pF. These ranges are exemplary and other values can be used to achieve the desired frequency. Also, other frequencies can be used such 13.56 MHz. All frequencies that are commonly received by receivers are envisioned as possible modifications to the tags return frequency. While other transceivers can easily be designed to receive drastically different frequencies, it is desirable to design this tag to work at this specific frequency so that it will be compatible with existing transceivers. While it is contemplated to have the transceiver emit a signal so that tag returns a signal at 8.2 MHz, or simply have the transceiver listen at a different frequency, it is desirable to enable the tag to be compatible with other tags and security systems. 
     Checkpoint Systems Inc, the assignee of the subject invention, commercially offers an EAS security tag under model designation of “410” EAS tag. That tag has the following basic properties.
         Front area etched=0.5807 sq. in.   Back area etched=1.6814 sq. in.   Design Frequency=8.4 MHZ.   Final Frequency=8.2 MHz   Q Range=70-75   Capacitance 141.2 pf   Inductance=2.495 uh   Number of turns=8   Coil line width=0.034 in.   Spacing between coils=0.01 in.   Width of margins=0.1 in.   Circuit Dimensions=1.55 in.×1.65 in.       

     If the signal strength that the 410 tag returns in free air when exposed to a rf interrogation signal from an rf antenna of a conventional EAS pedestal, such as that sold by Checkpoint Systems, Inc., under the trademark Liberty PX, is said to establish a reference of 1.0 units, then the tag of the current invention returns a signal with a strength of 2.5-6.0 units. Higher strengths are envisioned as technological limitations allow. The signal strength needs to be greater, because the metallic container has a shielding effect on the return signal. Thus the tag&#39;s return signal is made stronger so the receiver can receive an intelligible signal from the tag. 
     Every canister, jar, can, or container has a different disruptive capacity on the magnet field generated by the tag. Generally, the container disturbs the frequency the tag resonates at, and reduces the magnitude of the signal. The container can be modified by varying the capacitance or inductance of the tag to raise or lower the signal at which the tag resonates. In order to minimize the detriment of the tag&#39;s signal loss resulting from the metal of the container, the tag is spaced away from the container. While the unique properties of the container will determine how far the tag will need to be spaced, the tag will generally be spaced at least 1 cm from the top of the container. The further away the container is, the greater the signal strength. Combining the two steps yields the distance the tag should be spaced and the limitations of the structure of the tag. This new tag is designed so that when it is placed onto a metallic container a standard transceiver for security tags can detect the signal. 
     The tag is structured to be able to return a signal when attached to a metallic container means that it is required that the signal is strong enough so that a standard pedestal-style transceiver, the standard distance away (4-6 feet), can detect the signal. An example of a standard transceiver is the Checkpoint Liberty PX pedestal. 
     As alluded to earlier, the finished product, i.e., the container with the holding device supporting a security tag thereon spaced from the container, is made by placing the tag into the cap, placing the spacer under the tag (if the holding device makes use of a spacer element), placing the cap on the container&#39;s lid, and optionally placing a safety seal or wrap over the cap and container. Alternatively, one could place the cap on the bottom of the container and place a standard cap on the top of the device. Or one could place a tagged cap on the top and bottom of the device. 
     As should be appreciated from the foregoing one aspect of the subject invention entails use of a special cap or tag holder that has a spacer inside of it which effectively brings the tag a given distance away from the metal top, lid, or cap of a container to be tagged. This drastically reduces the effect the metal structure of the container has on shielding the resonance signal of the tag. Without the spacer, the container blocks or at least substantially degrades the tag&#39;s return signal. 
     As should be appreciated by those skilled in the art from the above, the subject invention includes several aspects, e.g., a holding device that optionally has a spacer inside of it to allow a security tag to be spaced far enough away from a metallic portion of a container to provide an intelligible signal to be received by the receiver, a security tag that is powerful enough and is calibrated correctly to send a discernable signal back to the transceiver amidst the distortion and shielding caused by the metallic portion of the container, and a method of designing and calibrating security tags for appropriate operation on containers having at least one metallic portion using the holding devices of this invention. It should also be pointed out at this juncture, that while use of the tag shown in  FIG. 3  is a preferred way to effectively tag a container having a metallic portion, conventionally constructed and shaped security tags may, in some cases, be used, depending upon the construction of the container/can and the size of the tag. 
     While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.