Abstract:
An electronic article surveillance (EAS) tag  20  having a metal attaching member  34  located therein and adapted to securely and releasably receive a shaft  52  of a pin therein, whereby a predetermined arcuate probe is inserted through an opening and applies a requisite force to the attaching member  34  to release the shaft  52.  There are no channels leading the authorized arcuate probe to the attaching member  34.  A plurality of partitions  58  and pillars  62  are interspersed within tag  20  to deflect any unauthorized probes from engaging and detaching attaching member  34.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    The contents of this application are related to a provisional application having serial No. 60/371,063 filed on Apr. 8, 2002, the contents of which are incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The invention relates to security tags in general, and in particular to a tag body containing an attaching means for use in electronic article surveillance (EAS) tags.  
         BACKGROUND OF THE INVENTION  
         [0003]    Various types of electronic article surveillance (EAS) systems are known having the common feature of employing a marker or tag which is affixed to an article to be protected against theft, such as merchandise in a store. When a legitimate purchase of the article is made, the marker can either be removed from the article, or converted from an activated state to a deactivated state. Such systems employ a detection arrangement, commonly placed at all exits of a store, and if an activated marker passes through the detection system, it is detected by the detection system and an alarm is triggered.  
           [0004]    For example, U.S. Pat. No. 5,426,419 to Nguyen et al., and assigned to Sensormatic Electronics Corporation, discloses an EAS tag having an arcuate channel that extends from an opening thereof to the actual attaching assembly and the detaching mechanism thereof. The channel increases the susceptibility of defeat of the attaching assembly because it guides an object that is inserted by an unauthorized individual directly to the attaching assembly and allows disengagement thereof.  
           [0005]    U.S. Pat. No. 6,373,390 to Hogan et al., assigned to the same assignee as the &#39;419 patent, is an improvement patent issued in light of the shortcomings of the &#39;419 patent. The &#39;390 patent admits that the EAS tag of the &#39;419 patent “can be defeated by insertion of a segment of relatively rigid metal bent in an arcuate manner to simulate the arcuate probe of the associated detacher device.” Furthermore, the &#39;390 patent describes a fish tape which may be formed to resemble the requisite arcuate probe in order to defeat the EAS tag of the &#39;419 patent, “the formed fish tape  50  is strong enough to hold its form when pushed into arcuate channel  7  until it can be manipulated into and against member  6 , which then can be rotated to release tack assembly  4 .” 
           [0006]    With respect to the &#39;419 and &#39;390 patent, many free standing arcuate probes have been either manufactured or misappropriated by unscrupulous individuals by dismantling the detacher components with which the probes are associated. The arcuate probe is inserted into the arcuate channel by hand and is lead directly to the preventing mechanism. In the &#39;390 device, the arcuate channel leads the manipulated arcuate probe to the opening or slot located in the arcuate channel, wherein the opening further aligns and guides the hand manipulated probe directly to the preventing mechanism or member. In addition, the force required to release the preventing mechanism of the &#39;419 and &#39;390 device is less than the force required to release the preventing mechanism of the instant invention. Accordingly, an unscrupulous individual may easily defeat the preventing mechanism of the &#39;419 and &#39;390 devices by manipulating an illicitly acquired freestanding arcuate probe.  
           [0007]    The &#39;419 and &#39;390 devices may be defeated by penetrating the bottom housing in proximal relation to the preventing mechanism and inserting a rigid and elongated element and forcing metal clip to rotate, whereby the preventing mechanism will release the pin. The instant device is more difficult to defeat in this manner.  
           [0008]    In addition, the preventing mechanism of the &#39;419 and &#39;390 patents is attached on only one end thereof, thus allowing movement out of the horizontal plane. Consequently, the vertical movement of the clamp increases the susceptibility of defeat of the attaching assembly because the jaws expand more easily because the angle of the clamp varies between the first end and second end as a result of the vertical movement of the non-secure end. The pull force to disengage a pin from the instant device and the &#39;419 device was conducted by using an Imada product model DPS220R, obtainable from 450 Skikie Blvd. #503, N. Brook, Ill. 60062.  
           [0009]    The prior art does not address the need for an EAS tag that is difficult to defeat. In addition, the prior art fails to provide a clamp assembly that requires greater pull force to disengage a pin from the clamp assembly. Furthermore, the prior art fails to provide a tag that is more difficult to defeat even when an unscrupulous individual has illicitly acquired a freestanding arcuate probe. Therefore, there remains a long standing and continuing need for an advance in the art of EAS tags that is more difficult to defeat, is simpler in both design and use, is more economical, efficient in its construction and use, and provides a more secure engagement of the article.  
         SUMMARY OF THE INVENTION  
         [0010]    Accordingly, it is a general object of the present invention to overcome the disadvantages of the prior art.  
           [0011]    Therefore, it is a primary objective of the invention to provide an EAS tag that is more difficult to defeat.  
           [0012]    It is another objective of the invention to provide a cost-efficient EAS tag.  
           [0013]    It is another objective of the invention to provide an EAS tag that is durable.  
           [0014]    It is yet another objective of the invention to provide an EAS tag that does not have an arcuate channel that may be used to guide an unauthorized detaching probe to the attaching member.  
           [0015]    It is a further objective of the invention to provide an EAS tag that is detachable when used with an authorized detaching unit.  
           [0016]    In keeping with the principles of the present invention, a unique EAS tag is disclosed wherein no channel is defined therein that will guide an unauthorized probe to the attaching member. The interior of the tag further has numerous partitions and pillars that will prevent insertion of the unauthorized probe if inserted in the wrong plane. In addition, the EAS tag will deflect the unauthorized probe into false paths.  
           [0017]    The EAS tag of the instant invention also discloses a metal clip that has an attaching region for receiving a shaft of a pin securely therein. The pin is removable when an authorized detacher is used to insert a probe into an opening within the EAS tag, and as a result of the secure fit of the tag within the detacher&#39;s nesting portion, the probe guides itself to the attaching member and applies a force thereto. The clip is slideably mounted onto at least one track that causes the clip to travel in a linear motion and causing the attaching region to release a shaft of the pin.  
           [0018]    Furthermore, an apex region of the EAS tag that encloses the attaching member has a honeycombed shape such that unauthorized probes cannot be inserted into holes created above the attaching member to manipulate the same.  
           [0019]    Such stated objects and advantages of the invention are only examples and should not be construed as limiting the present invention. These and other objects, features, aspects, and advantages of the invention herein will become more apparent from the following detailed description of the embodiments of the invention when taken in conjunction with the accompanying drawings and the claims that follow. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    It is to be understood that the drawings are to be used for the purposes of illustration only and not as a definition of the limits of the invention. In the drawings, wherein similar reference characters denote similar elements throughout the several views:  
         [0021]    [0021]FIG. 1 is a side elevational view of the tag of the instant invention in an assembled state.  
         [0022]    [0022]FIG. 2 is a side elevational view of the tag of the instant invention in an unassembled state.  
         [0023]    [0023]FIG. 3 is a perspective exploded view of the tag of the instant invention and the components thereof.  
         [0024]    [0024]FIG. 4 is a top plan view of the interior of second half of the instant tag with the tracks installed.  
         [0025]    [0025]FIG. 5 is a top plan view of the interior of second half of the instant tag with the tracks and the attaching member installed.  
         [0026]    [0026]FIG. 6 is a top plan view of the interior of first half of the instant tag illustrating an alternate preferred embodiment for accommodating an alternate resilient member.  
         [0027]    [0027]FIG. 7 is a top plan view of the interior of second half of the instant tag illustrating an alternate preferred embodiment for accommodating an alternate resilient member that attaches to first half illustrated in FIG. 6.  
         [0028]    [0028]FIG. 8 is a top plan view of the interior of first half of the instant tag illustrating an alternate preferred embodiment for accommodating an alternate resilient member.  
         [0029]    [0029]FIG. 9 is a top plan view of the interior of second half of the instant tag with the attaching member installed illustrating an alternate preferred embodiment for accommodating an alternate resilient member that attaches to first half illustrated in FIG. 8.  
         [0030]    [0030]FIG. 10 is a perspective view of the interior of first half of the instant invention.  
         [0031]    [0031]FIG. 11 is a perspective view of the interior of second half of the instant invention without the components therein.  
         [0032]    [0032]FIG. 11A is a perspective view of the interior of second half of the instant invention with the tracks and attaching member installed.  
         [0033]    [0033]FIG. 12 is a perspective view of a pin used with the instant invention.  
         [0034]    [0034]FIG. 12A is a frontal perspective view of the attaching member of the instant invention.  
         [0035]    [0035]FIG. 12B is a front elevational view of the attaching member of the instant invention.  
         [0036]    [0036]FIG. 12C is a side perspective view of the attaching member of the instant invention.  
         [0037]    [0037]FIG. 12D is a top perspective view of the first and second tracks used in the instant invention.  
         [0038]    [0038]FIG. 13 is a top plan view of the interior of the first half of an alternate preferred embodiment of the instant invention illustrating additional pillars and walls that may be placed within the tag to thwart an unauthorized probe insertion.  
         [0039]    [0039]FIG. 13A is a top plan view of the interior of the second half of an alternate preferred embodiment of the instant invention illustrating additional pillars and walls that may be placed within the tag to thwart an unauthorized probe insertion that attaches to first half illustrated in FIG. 13.  
         [0040]    [0040]FIG. 14 is a top plan view of the interior of the first half of an alternate preferred embodiment of the instant invention illustrating additional pillars that may be placed within the tag to thwart an unauthorized probe insertion.  
         [0041]    [0041]FIG. 14A is a top plan view of the interior of the second half of an alternate preferred embodiment of the instant invention illustrating additional pillars that may be placed within the tag to thwart an unauthorized probe insertion and attaches to the first half illustrated in FIG. 14.  
         [0042]    [0042]FIG. 15 is an electrical schematic diagram of the resonant tag circuit.  
         [0043]    [0043]FIG. 16 is a perspective view of the resonant tag circuit.  
         [0044]    [0044]FIG. 17 is a block diagram of an article surveillance system incorporating the resonant tag circuit.  
         [0045]    [0045]FIG. 18 is a cross-sectional view of a resonant tag system taken along line  18 - 18  of FIG. 16. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0046]    Referring now to FIGS. 1 and 2, a tag  20  is illustrated having a first half  22  and a second half  24 . First and second halves  22  and  24  are preferably made of a hard or rigid material. A usable rigid or hard material might be a hard plastic such as, for purposes of illustration but not limitation, an injection molded ABS plastic. If a plastic material is used, the mating of a first side wall  26  to a second side wall  28  can accomplished via an ultrasonic weld or like joining mechanism. However, it is to be understood that other joining methods, such as adhesives, may also be used. When first half  22  and second half  24  are securely joined, first sidewall  26  and second sidewall  28  form a peripheral outer wall of tag  20 . Second half  24  has an apex region  25  that extends therefrom in an opposing direction to first half  22 .  
         [0047]    Now referring to FIGS. 3, 4,  5 ,  11 , and  11 A, an exploded perspective view, top plan view, and perspective views illustrate the interior of second half  24 . Second half  24  receives at least a first track  30  therein, and in a preferred embodiment it also receives a second track  32 . First track  30  is tightly received within at least a first slot  31  and second track  32  is received tightly within at least a second slot  33 , such that tracks  30  and  32  are maintained in substantially parallel relations. Tracks  30  and  32  are made of a hard material such as, but not limited to, metal, which enhances the durability and performance of the tag  20 .  
         [0048]    An attaching member  34 , as described in greater detail hereinafter, slideably rests on at least first track  30 , but in a preferred embodiment, rests on both first and second tracks  30  and  32 . Attaching member  34  has a resilient member  36  that normally maintains an opening  38  defined on said attaching member  34  in axial alignment with an aperture  40  defined on the inside of second half  24  and a hole  42  defined on the interior of first half  22 . In one preferred embodiment, attaching member  34  is made of spring sheet metal. Resilient member  36  may be a resilient lever arm  43  and in an alternate preferred embodiment, as illustrated in FIGS. 7 and 9, at least one spring  44  may be substituted for the resilient lever arm  43 . Resilient member  36  is maintained in proximal relations to a barrier  45 , such that attaching member  34  is maintained in axial alignment described above.  
         [0049]    Now referring to FIGS. 6, 8, and  10 , the interior of first half  22  is illustrated having a reinforcement means  46  defining opening  42 . Reinforcement means  46  extends inwardly but does not interfere with the sliding action of attaching member  34  on first and second tracks  30  and  32 . At least a first ridge  48  extends inwardly from the interior of first half  22  and is in proximal relation to first track  30 . In a preferred embodiment, a second ridge  50  also extends inwardly from the interior of first half  22  and is in proximal relation to second track  32 . Ridges  48  and  50  prevent upward movement of attaching member  34 , yet do not interfere with the sliding arrangement of attaching member  34  over first and second tracks  30  and  32 . Ridges  48  and  50  are in substantially parallel relations to one another.  
         [0050]    Now referring to FIG. 12 and FIGS. 11 and 11A again in particular, in addition to the previous FIGS, a plurality of devices have been provided to prevent unauthorized manipulation and disengagement of attaching member  34 . When first half  22  and second half  24  are assembled, a shaft  52 , having a plurality of indentations  54  at predetermined intervals along the length thereof, is inserted through hole  42  and is received securely yet removably within opening  38  of attaching member  34 . Shaft  52  further extends into aperture  40 , which is defined by a tubular formation  41  extending inwardly from second half  24 . A top  55  is securely maintained at one end of shaft  52 , such that an opposing end of shaft  52  traverses an article to be monitored and is maintained within opening  38  of attaching member  34  and aperture  40 , whereby the article is securely bound between top  55  and outer surface of tag  20 .  
         [0051]    Now also referring to FIGS. 12A, 12B, and  12 C, attaching member  34  has a forward edge  75  and a distal rearward edge  77 . An attaching region  78  is defined proximal to the forward edge  75  and resilient member  36  is located proximal to rearward edge  77 . A first region  80  and a second region  82  are divided by attaching region  78 . A first lip  84  extends downwardly from first region  80  and a second lip  86  extends downwardly from second region  82 , such that first lip  84  and second lip  86  are in substantially parallel relations to one another, and each of the lips  84  and  86  are in substantially perpendicular relation to first and second regions  80  and  82  respectively. A first interior wall  88  and a second interior wall  90  are created by lips  84  and  86  respectively. First lip  84  and second lip  86  extend beyond rearward edge  77  and form a first outward curve  92  and a second outward curve  94  respectively, on a side of attaching member  34  proximal to resilient member  36 . Opening  38  of attaching member  34  is defined by a first jaw  96  and an opposing second jaw  98 . Jaws  96  and  98  extend downwardly from the plane of first and second regions  80  and  82  and are in proximal relations when they define opening  38 . However, jaws  96  and  98  are flexible such that they can move towards one another to decrease the size of opening  38  or they can move away from one another to increase the size of opening  38 . As a result, shaft  52  is maintained within opening  38  as defined by jaws  96  and  98  in a secure, yet removable, manner.  
         [0052]    Now also referring to FIG. 12D, first track  30  has a first top edge  100  and a first bottom edge  104  which are distal to one another and are interconnected by a first front edge  108  and an opposing first back edge  112 . Second track  30  has a second top edge  102  and a second bottom edge  106  which are distal to one another and are interconnected by a second front edge  110  and an opposing second back edge  114 . First back edge  112  and second back edge  114  are curved to accommodate the curved portion of second side wall  28  where apex  25  is created. First track  30  has a first outer surface  116  and a first inner surface  120  and second track  32  has a second outer surface  118  and a second inner surface  122 .  
         [0053]    In order to disengage shaft  52  from jaws  96  and  98 , enough force must be applied to forward edge  75  of attaching member  34  to overcome the force exerted by the resilient member  36 , and to move attaching member  34  towards rearward edge  75 . In addition, the force must be sufficient to overcome the frictional force created between first interior wall  88  and second outer surface  118  and the frictional force created between second interior wall  90  and first outer surface  116 . In order to do so, a probe of a predetermined shape and length must be inserted through entrance  56  of tag  20  and extend to attaching member  34  to apply the sufficient necessary force to forward edge  75  to overcome the force exerted by the resilient member  36  and the frictional force described above to allow sufficient linear movement along first and second tracks  30  and  32  to disengage and remove shaft  52  from first and second jaws  96  and  98 . U.S. Pat. No. 4,738,258 is hereby incorporated by reference for teaching the probe required and the necessary actuation thereof for insertion into entrance  56 . U.S. Pat. No. 4,738,258 can be modified into the disengagement apparatus illustrated in U.S. Pat. No. 5,426,419 and U.S. Pat. No. 5,535,606, the teachings of the detacher are also incorporated herein by reference.  
         [0054]    To determine the force required to disengage the shaft  52  from jaws  96  and  98  of attaching member  34  of the instant invention as compared to the tag of the &#39;419 patent, the following experiment was conducted on ten tags  10  of the instant invention and ten tags produced in accordance with the specification of the &#39;419 patent. A spring balance was hung on a wall, with its spring loading hook at the bottom. Two ends of a cotton sling were tied to form a loop. One end of the loop was secured on the hook of the balance whereas the other end was wound through the handle such that a downward pull force on the detacher (as illustrated in FIGS. 11 and 12 of the &#39;419 patent) led to the squeezing of the detacher&#39;s trigger. Because the spring balance is in series with the sling, a measure of the triggering force to detach the tack shaft  52  could be measured. On average, approximately five pounds more force was required to detach the shaft  52  from the attaching member  34  of the instant invention than the tag of the &#39;419 patent.  
         [0055]    In order to defeat the introduction of unauthorized probes into entrance  56 , several false paths and barriers are provided within tag  20  and the arcuate channel of the &#39;419 patent and the &#39;390 patent are completely eliminated. Because apex region  25  of tag  20  is constructed to be securely retained within a nesting or cradle area of a detacher, as taught by the &#39;419 patent, tag  20  does not require any arcuate channels to lead the detaching probe to the forward edge  75  of the attaching member  34 . The predetermined shape of the detaching probe and the predetermined positioning of the attaching member  34  allow an authorized individual using an authorized detacher to disengage the shaft  52  from jaws  96  and  98 , thereby releasing the attached article. Dashed line  99 , of FIG. 5, illustrates a proper path that may be taken by the detaching probe.  
         [0056]    However, to defeat even the introduction of a probe that has been illicitly disassembled from an authorized detacher, a first partition  58  prevents entrance of the unauthorized probe if at an incorrect plane. A second partition  60  having a greater height than first partition  58 , also prevents the introduction of an unauthorized probe to attaching member  34 . A first pillar  62  and a second pillar  64  also prevent application of force to attaching member  34  by an unauthorized probe by deflecting the same. A third partition  66 , a fourth partition  68 , a fifth partition  70 , and sixth partition  72  are at different levels and define a plurality of cavities  74  therebetween. Cavities  74  extend within apex region  25  and are substantially perpendicular to the plane of attaching member  34 , such that an unauthorized probe inserted through apex region  25  will be retained within a single cavity  74  and will not be able to manipulate attaching member  34  laterally to disengage shaft  52 .  
         [0057]    Furthermore, if an unauthorized probe is being manipulated by hand, the probe will not be inserted at the correct plane to make proper contact with forward edge  75  of attaching member  34  to disengage the same. Instead, the unauthorized probe will go into the space defined between attaching member  34  and the different partitions  66 ,  68 ,  70 , and  72 . FIGS. 13 and 13A teach an alternate preferred embodiment with different barriers to prevent access to the attaching member  34  of tag  20 . FIGS. 14 and 14A teach an alternate preferred embodiment with further different barrier arrangements to prevent access to the attaching member  34  of tag  20 .  
         [0058]    Referring now also to FIG. 15, therein is illustrated a schematic diagram of a resonant tag circuit  124 . In a preferred embodiment, circuit  124  has at least an inductive element  126  and at least a capacitance element  128  connected in a series loop and forming an inductive capacitance (LC) resonant circuit  124 . The resonant tag circuit is employed in connection with electronic article security systems particularly electronic article security systems of the radio frequency or RF electromagnetic field type. Such electronic article security systems are well known in the art and a complete detailed description of the structure and operation of such electronic article security systems is consequently not necessary for an understanding of the present invention.  
         [0059]    However, as illustrated in FIG. 17, such electronic article security systems employing resonant tag circuits include a transmitting means  130  for transmitting electromagnetic energy at or near the resonant frequency of the resonant tag into or through a surveillance zone  132 . A detecting means  134  monitors the surveillance zone  132  for the presence of a resonant tag within the surveillance zone  132 . Surveillance zone  132  is generally proximate to an entrance and/or exit of a facility such as, but not limited to, a retail store. The security system&#39;s function is to detect the presence within the surveillance zone  132  a monitored article having a resonant tag circuit  124  attached thereto in a secure fashion.  
         [0060]    In such a system, transmitting means  130  transmits pulses in the form of RF bursts at a frequency in the low radio-frequency range, such as 58 kHz in a preferred embodiment but may be adapted to be at any appropriate frequency as desired. The pulses (bursts) are emitted (transmitted) at a repetition rate of, for example 60 Hz AC cycle, with a pause between successive pulses. The detecting means  134  includes a receiver  136  which is synchronized (gated) with the transmitting means  130  so that it is activated only during the pauses between the pulses emitted by the transmitting means  130 . The receiver  136  expects to detect nothing in these pauses between the pulses. If an activated tag is present within the surveillance zone  132 , however, the resonator therein is excited by the transmitted pulses, and will be caused to oscillate at the transmitter frequency, i.e., at 58 kHz in the above example. The resonator emits a signal which rings at the resonator frequency, with an exponential decay time (“ring-down time”). The signal emitted by the activated tag, if it is present between transmitting means  130  and the receiver  136 , is detected by the receiver  136  in the pauses between the transmitted pulses and the receiver accordingly triggers an alarm  138 . Alarm  138  may be audible and/or visual or can be a silent alarm that is detected by any means known in the art.  
         [0061]    In a preferred embodiment, to minimize false alarms, the detecting means  134  usually must detect a signal in at least two, and preferably four, successive pauses; however, it is to be understood that the present invention can be adapted to function within one pause. Furthermore, in order to further minimize false alarms, such as due to signals produced by other RF sources, the receiver  136  employs two detection windows within each pause. The receiver  136  integrates any 58 kHz signal (in this example) which is present in each window, and compares the integration results of the respective signals integrated in the windows. Since the signal produced by the tag is a decaying signal, if the detected signal originates from a resonator in a tag it will exhibit decreasing amplitude (integration result) in the windows. By contrast, an RF signal from another RF source, which may coincidentally be at, or have harmonics at, the predetermined resonant frequency, would be expected to exhibit substantially the same amplitude (integration result) in each window. Therefore, alarm  138  is triggered only if the signal detected in both windows in a pause exhibits the aforementioned decreasing amplitude characteristic in each of a number of successive pauses.  
         [0062]    For this purpose, as noted above, the receiver electronics is synchronized by a synchronization circuit with the transmitter electronics. The receiver electronics is activated by the synchronization circuit to look for the presence of a signal at the predetermined resonant frequency in a first activation window of about 1.7 ms after the end of each transmitted pulse. For reliably distinguishing the signal (if it originated from the resonator) integrated within this first window from the signal integrated in the second window, a high signal amplitude is desirable in the first window. Subsequently, the receiver electronics is deactivated, and is then re-activated in a second detection window at approximately 6 ms after the original resonator excitation, in order to again look for and integrate a signal at the predetermined resonant frequency. If such a signal is integrated with approximately the same result as in the first detection window, the evaluation electronics assumes that the signal detected in the first window did not originate from a marker, but instead originated from noise or some other external RF source, and alarm  138  therefore is not triggered.  
         [0063]    Now also referring to FIGS. 16 and 18, therein is illustrated a preferred embodiment of the resonant tag circuit  124 . Inductive element  126  is formed by a conducting member  140  that is made of any material that is capable of conducting electricity, and in a preferred embodiment is made of copper. Conducting member  140  is coiled around a first member  142  that is preferably constructed of a non-conductive material such as, but not limited to, plastic and rubber. First member  142  has a first wall  144  and a second wall  146  that are interconnected by a middle portion  148 . First wall  144 , second wall  146 , and middle portion  148  axially define a cavity  150  extending therethrough.  
         [0064]    Middle portion  148  is adapted to receive conducting member  140  thereon in a coiled fashion on an outer surface  152  thereof between first wall  144  and second wall  146 . Middle portion  148  has an inner surface  154  that defines cavity  150 . A magnetic member  156  is adapted to be received within cavity  150  and to be frictionally retained within inner surface  154  of middle portion  148 . Magnetic member  156  may be a ferromagnetic material or any other material having magnetic properties, and in a preferred embodiment, magnetic member  156  is made of amorphous metals.  
         [0065]    Capacitance element  128  is a parallel plate capacitor formed of conductive material on a first plate and a second plate (not shown) that are known in the art. Capacitance element  128  is adapted to be received on first member  142 , and in a preferred embodiment is received on first wall  144  thereof. First plate and second plate of capacitance element  128  are attached to opposing ends of conducting member  140  to form a series circuit.  
         [0066]    When resonant tag circuit  124  enters a surveillance zone  132  it is subjected to an electromagnetic field and magnetic member  156  is charged. As the electromagnetic field is removed, the stored magnetic energy stored in the magnetic member  156  is released and thus an ac current is generated within inductive element  126  and capacitance element  128 . When an ac voltage is applied to the resonant tag circuit  124 , the current depends on the frequency thereof. The resonant frequency of circuit  124  can be determined by the following equation:  
       fo   =     1     2                 π                   LC                               
 
         [0067]    Wherein f o  is the resonant frequency of the circuit and L is the inductance and C is the capacitance. As can be ascertained from the equation, many possible combinations yield the desired resonant frequency, however, the L to C ratio is preferably kept high in order for the circuit to be selective and minimize undesirable resonances to disturbances close to the resonant frequency thus minimizing false alarms. In a preferred embodiment, optimal values were determined to be L=2.08 mH and C=3.6 nF thus yielding an L to C ratio of 577,777.78.  
         [0068]    It is to be understood that resonant tag circuit  124  is of sufficient size to be stored within casings used in article surveillance systems. Specifically, tag circuit  124  is of sufficient size to be received and enclosed within compartment  76  of tag  20 . Compartment  76  is defined by a peripheral wall  158  extending inwardly from second half  24  to enclose the resonant tag circuit  124  therein. A false path  160  is created between second side wall  28  and peripheral wall  158 .  
         [0069]    If an article having resonant tag circuit  124  attached thereto via tag  20  is moved into the surveillance zone  132 , the alarm  138  will be activated by circuit  124  to signify unauthorized removal of the article through a specified area. For purposes of illustration but not limitation, in a preferred embodiment, the length of circuit  124  is less than 2 cm and the radius thereof is less than 1 cm. However, it is to be understood that alternate sizes and shapes of circuit  124  will also function as taught and alternate electronic detection circuits as are known in the art may also be used.  
         [0070]    While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible without departing from the essential spirit of this invention. Accordingly, the scope of the invention should be determined not by the embodiment illustrated, but by the appended claims and their legal equivalents.