Patent Publication Number: US-9836935-B2

Title: Electronic article surveillance

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application is a CONTINUATION of the U.S. Non-Provisional Utility patent application Ser. No. 13/869,725, filed Apr. 24, 2013, now U.S. Pat. No. 9,368,011, which claims the benefit of priority U.S. Provisional Utility Patent Application No. 61/637,454, filed Apr. 24, 2012, the entire disclosure of which is expressly incorporated by reference herein. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the incorporated reference does not apply. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention relates to article surveillance systems and, more particularly, to a point of sale (POS) electronic article surveillance (EAS) system. 
     Description of Related Art 
     Conventional EAS systems with EAS pedestal systems that are positioned at the ingress/egress locations of a retail store are well known have been used for a number of years. Regrettably, placement of the EAS pedestal systems only at the entry/exit location of retail stores does not provide a sufficient protection for the protected items. For example, as illustrated in  FIG. 1 , a shopper  102  may include hidden tagged merchandise  110   a  inside their clothing while including other merchandise inside a shopping cart  104 . The shopper  102  may unintentionally place one or more small, EAS tagged items  110   b  at the bottom of the shopping cart  104 , with several EAS larger items  110   c  at the top thereof. The shopper  102  may also intentionally hide smaller tagged items  110   d  within a EAS larger tagged item  110   c . In either instance, the sales clerks may neutralize an EAS tag of the EAS larger tagged items  110   c  but without noticing the hidden EAS tagged item  110   a , smaller EAS tagged items  110   b  at the bottom of the cart  606 , or EAS tagged item  110   d  within the EAS larger tagged item  110   c . In such an instance, shoppers pay for the scanned larger EAS tagged items  110   c , but not the inconspicuous and intentionally hidden smaller items EAS tagged item  110   a , EAS tagged item  110   b , and or the EAS tagged item  110   d . Of course, the EAS tagged smaller items  110   a ,  110   b , and  110   d  not neutralized trigger an alarm when the shoppers  102  pass through the entry/exit EAS pedestals systems. However, in most instances, it is a general retail policy to not follow a shopper outside the retail store and in fact, in most cases the sales clerks are under the false impression that they have neutralized all tagged items correctly (as all visible tagged items were neutralized), and interpret the triggered alarm as a false alarm, allowing the shopper (who may be part of an organized retail crime) to simply exit the store without paying or processing the smaller EAS tagged items  110   a ,  110   b , and  110   d.    
     Accordingly, in light of the current state of the art and the drawbacks to current EAS systems, a need exists for an EAS system that would allow detection of EAS tagged items at a point of sale to thereby prevent shoplifting and organized retail crime. 
     BRIEF SUMMARY OF THE INVENTION 
     A non-limiting, exemplary aspect of an embodiment of the present invention provides a method for surveillance of articles, comprising:
         generating an electronic article surveillance (EAS) field at a point of sale (POS) that defines a POS EAS surveillance zone;   detecting EAS tags associated with the articles that are within the generated POS EAS surveillance zone;   communicating existence of detected EAS tags at the POS with an indictor until the EAS tags at the POS are neutralized.       

     Another non-limiting, exemplary aspect of an embodiment of the present invention provides a security system, comprising:
         a point of sale (POS) structure; and   an Electronic Article Surveillance (EAS) system that is associated with the POS structure.       

     Still another non-limiting, exemplary aspect of an embodiment of the present invention provides a point of sale (POS) structure, comprising:
         an Electronic Article Surveillance (EAS) system.       

     Such stated advantages of the invention are only examples and should not be construed as limiting the present invention. These and other features, aspects, and advantages of the invention will be apparent to those skilled in the art from the following detailed description of preferred non-limiting exemplary embodiments, taken together with the drawings and the claims that follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It is to be understood that the drawings are to be used for the purposes of exemplary illustration only and not as a definition of the limits of the invention. Throughout the disclosure, the word “exemplary” may be used to mean “serving as an example, instance, or illustration,” but the absence of the term “exemplary” does not denote a limiting embodiment. Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. In the drawings, like reference character(s) present corresponding part(s) throughout. 
         FIG. 1  is a non-limiting exemplary illustration of a shopper with a shopping cart, including EAS tagged items; 
         FIGS. 2A and 2B  are a non-limiting, exemplary illustration of a POS EAS system in accordance with an embodiment of the present invention; 
         FIGS. 3A to 3C  are non-limiting, exemplary schematic illustrations of an EAS transceiver controller module of a POS EAS system in accordance with an embodiment of the present invention, including non-limiting, exemplary illustrations of EAS system antenna transmission patterns; 
         FIG. 4A  is non-limiting, exemplary illustration of the internal signal processing of received signals in accordance with the present invention; 
         FIGS. 4B and 4C  are non-limiting, exemplary schematic flowchart diagrams for the processing of antenna signals from an acousto-magnetic EAS system by a microprocessor in accordance with the present invention; and 
         FIGS. 4D to 4I  are non-limiting, exemplary schematic signal graphs of antenna signals of an acousto-magnetic EAS system, including signal analysis, timing, and illustration of ant-jamming method in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of presently preferred embodiments of the invention and is not intended to represent the only forms in which the present invention may be constructed and or utilized. 
     For purposes of illustration, programs and other executable program components are illustrated herein as discrete blocks, although it is recognized that such programs and components may reside at various times in different storage components, and are executed by the data processor(s) of the computers. Further, each block within a flowchart may represent both method function(s), operation(s), or act(s) and one or more elements for performing the method function(s), operation(s), or act(s). In addition, depending upon the implementation, the corresponding one or more elements may be configured in hardware, software, firmware, or combinations thereof. 
     In the description given below and the corresponding set of drawing figures, when it is necessary to distinguish the various members, elements, sections/portions, components, or any other aspects (functional or otherwise) or features of a device(s) or method(s) from each other, the description and the corresponding drawing figures may follow reference numbers with a small alphabet character such as (for example) “EAS tagged items  110   a ,  110   b ,  110   c ,  110   d , and etc.” If the description is common to all of the various members, elements, sections/portions, components, or any other aspects (functional or otherwise) or features of a device (s) or method(s) such as (for example) to all EAS tagged items  110   a ,  110   b ,  110   c ,  110   d , and etc., then they may simply be referred to with reference number only and with no alphabet character such as (for example) “EAS tagged item  110 .” 
     Throughout the disclosure, a “structure” may refer to any one or combination of fixture, display, furniture, shelves, cabinetry, etc., such as a checkout counter, cash wrap, table, and so on. 
     Further, phrases such as “point of sale” (POS), “point of transaction” (POT) or the like generally refer to a specific location (that may or may not include a “structure”) where (or at which point or location) a transaction is completed. Throughout disclosure the terms POS or POT are deemed equivalent and interchangeable. 
     A point of sale (POS) system is generally referred to one or more machines that facilitate transactions at the POS. Non-limiting examples of POS systems may include computerized systems, networked cash registers, barcode reader, card reader, etc. that are generally located at the point of sale. 
     Throughout the disclosure, references to any one or more specific types of security Electronic Article Surveillance (EAS) systems are meant as illustrative, for convenience of example only, and should not be limiting. Non-limiting, non-exhaustive listings of examples of EAS systems that may be used with any one or more embodiments of the present invention may include Electromagnetic (EM) EAS systems, Radio Frequency (RF) EAS systems, Acousto-magnetic (AM) EAS systems, Microwave (MW) EAS system, etc., or any combinations thereof. 
     The present invention provides a very small and compact POS EAS system that is inconspicuously associated with a conventional POS structure that allows for seamless processing and detection of articles at the POS. That is, articles with EAS tags are seamlessly detected and processed at the POS prior to entry of the EAS tagged articles (if any) to within the detection zone of EAS pedestal systems, which are conventionally located at ingress/egress retail locations. The small, compact form of the POS EAS system of one or more embodiments of the present invention allows for inconspicuous mechanical integration thereof with most conventional POS structures without modifying the exterior “look and feel” of the POS structure or taking additional space at or near the POS location of a typical retail store. 
       FIGS. 2A and 2B  are a non-limiting, exemplary illustration of a POS EAS system in accordance with an embodiment of the present invention. As illustrated in  FIGS. 2A and 2B , the security system of the present invention is the POS EAS system  200  that is comprised of a POS structure  202  that includes an EAS system  224 . Accordingly, with the POS EAS system  200  of the present invention, when the shopper  102  (shown in  FIG. 1 ) approaches within the vicinity of the POS structure  202 , the associated EAS system  224  immediately detects all EAS tags  110  of the items that are on the shopper  102  or carried by the shopper  102  via the shopping cart  104  into a POS EAS surveillance zone  208 . The detection of all EAS tags  110  is continuously and discretely communicated with a sales clerk  220  via an inconspicuously positioned indicator alarm  222 . The indicator alarm  222  is continuously driven and maintained in a first mode of operation (e.g., a visual indicator alarm having red color light as “EAS tag detected”) as a result of existence of EAS tags  110  within the POS EAS surveillance zone  208  until all of the EAS tags  110  at the POS structure  202  are neutralized at which point, the indicator alarm  222  is continuously driven and maintained in a second mode of operation (e.g., the visible indicator alarm  222  having a green color light as “EAS tag not detected”). 
     With an embodiment of the present invention, the sales clerks  220  seamlessly proceed processing the EAS tagged items  110  at the POS  212  in a well known and conventional manner, including neutralizing each visible EAS tag of all visible EAS tagged items  110  using conventional EAS tag deactivator  216 , but without noticing (or even knowing about) the hidden EAS tagged item  110   a  on the shopper  102 , the smaller EAS tagged items  110   b  at the bottom of the cart  104 , or the EAS tagged item  110   d  within the larger, visible EAS tagged item  110   c  (all shown in  FIG. 1 ). 
     Upon processing (e.g., neutralizing) all visible EAS tagged items  110  in a well known and conventional manner using the EAS tag deactivator  216 , and prior to finalizing the transaction (e.g., using a POS system  226 ), the sales clerk  220  then checks the indicator alarm  222  to determine the continued existence of EAS tagged items  110  within the vicinity of the POS structure  202 . In the present instance, with the shopper  102  having hidden EAS tagged items  110 , the sales clerk  220  is discretely informed by the indicator alarm  222  about the continued presences or existence of EAS tagged items  110  (with the indicator  222  operating in the first mode of operation) at which time, the sales clerk  220  may simply follow retail store policy, for example, informing a manager about continued existence of non-visible or non-viewable (or hidden) EAS tagged items  110  at the POS  212  before finalizing the transaction. Therefore, with the present invention, the sales clerks  220  are no longer under the false impression that they have neutralized all EAS tagged items  110  correctly just because they see no other visible EAS tagged item  110  that is visible, and would no longer allow a shopper to simply exit the store without paying or processing all EAS tagged items  110  at the POS  212 . 
     As further illustrated in  FIGS. 2A and 2B , one or more embodiments of the present invention provide the EAS system  224 , one or more components of which may be associated with the POS structure  202 , forming the POS EAS system  200 . More specifically, one or more preferred embodiments of the present invention provide one or more EAS antenna systems  204  (of the EAS system  224 ) that are mechanically integrated (physically connected) with the POS structure  202 . 
     In general, it is preferred that the EAS antenna system  204  is inconspicuously associated with the POS structure  202 , and positioned at a transaction side  206  of the POS structure  102  closest to where an actual POS transaction is conducted rather than the transaction processing side  214  (closest to the sales clerks  220 ). The placement of the EAS antenna system  204  at the transaction side  206  of the POS structure  202  enables the EAS antenna system  204  to generate an EAS field at the POS that defines the POS EAS surveillance zone  208  for detection of EAS tagged items  110  within the POS EAS surveillance zone  208 . Further, it should be noted that if the EAS antenna system  204  is mounted onto a metal POS structure, the antenna housing is generally and preferably positioned slightly away or distance from the body of the metal POS structure to avoid potential flux interferences. 
     As further illustrated in  FIGS. 2A and 2B  and described above, the EAS system  224  discreetly communicates with the indicator alarm  222 , which is inconspicuously associated with the POS structure  202  and is positioned at the transaction processing side  214  of the POS structure  202  to be clearly viewable by the sales clerks  220 . In general, the indicator alarm  222  is continuously driven and maintained in the first mode of operation as a result of existence of EAS tagged items  110  within the POS EAS surveillance zone  208  until the EAS tagged items  110  at the POS are neutralized at which point, the indicator alarm  222  is continuously driven and maintained in a second mode of operation. The indicator alarm  222  may be an audio indicator, a visual indicator, and or an audio-visual indicator that may be coupled with (or plugged into) an EAS system controller module  218 . 
       FIGS. 3A to 3C  are non-limiting, exemplary schematic illustrations of an EAS transceiver controller module of a POS EAS system in accordance with an embodiment of the present invention, including illustrations of EAS system antenna transmission patterns. As illustrated in  FIGS. 3A to 3C , the POS EAS system  200  includes an EAS transceiver controller module  218  that couples with the EAS antenna system  204  for controlling the EAS antenna system  204 . The EAS antenna system  204  may be coupled with the EAS transceiver controller module  218  by cables  380  to provide a simple “plug &amp; play” EAS system  224 . It should be noted that  FIGS. 3A to 3D  schematically illustrate an Acousto-Magnetic (AM) EAS system  224  for discussion purposes only and therefore, should not be limiting. 
     The AM the EAS system  224  illustrated in  FIGS. 3A to 3C  includes the EAS transceiver antenna system  204  that is comprised of a first inductor coil  302  and a second inductor coil  304 , with the EAS transceiver controller module  218  coupled with both the first and the second inductor coils  302  and  304 . As best illustrated in  FIGS. 3B and 3C , the first inductor coil  302  and the second inductor coil  304  are accommodated within an antenna housing  370 , and associated with the transaction side  206  of the POS structure  202 . 
     The first inductor coil  302  forms an upper loop of the transceiver antenna  204  with substantially rectangular curved corners, and the second inductor coil  304  forms a lower loop of the transceiver antenna  204  with substantially rectangular curved corners. The first and second inductor coils  302  and  304  are mutually arranged and positioned to minimize (or eliminate) flux interferences while maintaining their respective independent and autonomous operational principles. Accordingly, the mutual arrangement, orientation, and actual physical positioning of the first and second loops  302  and  304  within a shared space of the antenna housing  370  is configured to achieve minimal flux interference, which enables the transmission of EAS surveillance signals in the desired pattern (detailed below) with no induced current in the inductor coil  302  or  304  which is not actuated (detailed below). 
     As further illustrated in  FIGS. 3B and 3C , a bottom portion  374  of the upper loop  302  overlaps a top portion  376  of the lower loop  304 . This overlapping arrangement of the antenna loops  302  and  304  is preferred as the overall size of the antenna  204  is reduced by the overlapping span and hence, the antenna system  204  takes less space, allowing for an easy fit within most POS structures  202 . Accordingly, the antenna loops  302  and  304  are parallel and in common plane in relationship to one another, with the overlapping portions that touch. However, it should be noted that the bottom portion  374  of the upper loop  302  may also be positioned a specific distance away from a top portion  376  of the lower loop  304  where no overlap occurs. The specific distance desired is determined and is based on many factors, non-limiting examples of which may include loop size, number of loops, the magnetic flux generated, etc. Accordingly, if space is not of concern, then the loops  302  and  304  need not be overlapped without change in the operation of the POS EAS system  200 . 
     As illustrated in  FIGS. 3B and 3C , an embodiment of the present invention uses two antenna loops  302  and  304  in combination with a specific transmission pattern (detailed below and illustrated in  FIG. 3C ) to detect an EAS tag  302  that is positioned or placed within the POS EAS surveillance zone  208  at any orientation to thereby eliminate potential detection-holes or “blind-spots.” In  FIG. 3C , solid lines are used to indicate active or transmitting antenna loops and dashed lines are used to indicate non-active or non-transmitting antenna loops. Further, the indicated pattern of activating any one or both antenna loops  302  and  304  need not be in any particular order or sequence. For example, the pattern of activation may start with activating the second antenna loop  304 , then the first and the second antenna loops  302  and  304  together as indicated, and finally the first antenna loop  302 . Alternatively, antenna loop activation pattern may start with the first antenna loop  302 , then the second antenna loop  304 , and finally the activation of both the first and the second antenna loops  302  and  304 . As another example, antenna loop activation pattern may start with activation of both the first and the second antenna loops  302  and  304  first, and then individual activation of the antenna loops  302  and  304 . Accordingly, any permutation of the illustrated activation scheme is possible so long as the antenna loops  302  and  304  are activated individually as illustrated and also activated together as illustrated, representing a full cycle. 
     As best illustrated in  FIGS. 3A to 3C , the transceiver controller module  218  in a transmitter mode of operation (under the control of a Central Processing Unit (CPU)  306 ) may drive the first inductor coil  302  to generate a first transmission signal in a form of a first magnetic field. The first drive signal (the current) through the first or upper loop  302  generates a first magnetic field that is best suited for detection of EAS tags  110  in the Z-orientation and in particular, the detection is best at the upper and lower horizontal portions  372  and  374  of the upper loop  302  to detect EAS tags  110  in the Z-orientation. 
     It should be noted that since the EAS system  224  (including the controller module  218  and the antenna system  204 ) operates as a transceiver system, after every single transmission, the CPU  306  switches the mode of operation of the EAS transceiver controller module  218  and the transceiver antenna system  204  from the transmitter mode of operation to a receiver mode of operation. Accordingly, once a transmission signal is transmitted (e.g., the first transmission signal via the first inductor coil  302 ), the CPU  306  switches the mode of operation of the EAS system  224  from transmitter to the receiver mode of operation after a short delay (which enables the transmission of an already transmitted signal to be completed). 
     In a receiver mode of operation, the transceiver controller module  218  receives detected EAS signals of EAS tags  110  within the POS EAS surveillance zone  208  through both the first and second inductor coils  302  and  304  of the transceiver antenna system  204  (which operate as receiver antenna loops when in the receiver mode of operation). The received EAS signal from the POS EAS surveillance zone  208  is then stored for further processing by the transceiver control module  218  after which, the transceiver control module  218  (under the control of the CPU  306 ) switches back to transmitter mode of operation to transmit another transmission signal. The back and forth switch between the transmitter mode of operation and the receiver mode of operation continues until a fully cycle of the transmitter pattern of the antenna loops  302  and  304  (shown in  FIG. 3C ) in the transmitter mode of operation is complete, with all the EAS signals detected during the receiver mode of operation stored for later processing by the transceiver controller module  218 . 
     In particular, after driving the first inductor coil  302  to generate a first transmission signal in a form of a first magnetic field, switching back to the receiver mode of operation after a short delay to receive potential EAS tag  110  signals, and storing the EAS tag signals (if any), the transceiver controller module  218  switches back to the transmitter mode of operation to drive the second inductor coil  304  to generate a second transmission signal in a form of a second magnetic field. The current through the lower loop  304  generates a magnetic field best suited for detection of EAS tags  110  in the Z-orientation, in particular, the detection is best at the upper and lower horizontal portions  376  and  378  of the lower loop  304  to detect EAS tags in the Z-orientation. It should be noted that the combination of the active upper loop  302  only and active lower loop  304  only provides full detection along all orientation, with the first and second magnetic fields defining a complete POS EAS surveillance zone. However, it has been found that detection of EAS tags  110  in the X-Y orientation is weaker when using only the first generated magnetic field and only the second generated magnetic field. Accordingly the transceiver controller module  218  in the transmitter mode of operation further drives both the first and the second inductor coils  302  and  304  together and in phase to generate both the first transmission signal and the second transmission signal in phase, forming a third transmission signal in a form of a third magnetic field. The current through the first and the second inductor coils  302  and  304  are in the same direction (in phase), generating the third magnetic field (along the dotted area  378 ) best suited for detection of EAS tags  110  in the X-Y-orientation. The first, second, and third magnetic fields more optimally define the POS EAS surveillance zone  208 . 
     As indicated above, the transceiver control module  218  is switched to a receiver mode of operation (after a short delay) after transmitting any one of the first, second, and third transmission signals after which, the transceiver control module  218  is switched back to transmitter mode of operation to transmit another one of the first, second, and third transmission signals. 
     Referring back to  FIG. 3A , the transceiver controller module  218  includes a power pack (with a step-down transformer)  358  for powering the EAS system  224 , including the transceiver controller module  218  and the EAS transceiver antennas  204 . The CPU  306  generates the one or more drive signals (which are digital signals at a desired frequency) through a first transmit signal line  308 , a second transmit signal line  322 , or both the first and the second transmit signal lines  308  and  322  to respectively drive the first inductor loop  302 , the second inductor loop  304 , or both the first and second inductor loop  302  and  304 . Accordingly, as an example, to energize the first inductor loop  302  only, the CPU generates the desired drive signal for that loop through the first transmit signal line  308  only, with no drive signal on the second transmit signal line  322 . The drive signals through the first transmitter signal line  308  and the second transmitter signal line  322  may have the same frequency with either the same or different phases. In particular, an embodiment of the present invention provides drive signals that have the same frequency but opposite phases when activating both the first inductor loop  302  and the second inductor loop  304  together (shown in  FIG. 3C ). The frequency used (e.g., about 58 KHz) may be commensurate with the type of EAS system used (e.g., AM EAS system). 
     The EAS transceiver controller module  218  further includes digital potentiometer  312  and  326 , which are digitally controlled variable resistors that are controlled by the CPU  306  via the PWR SET pin signal line  310  and  324  to control the magnitude of the power of the respective digital drive signals output from the first transmitter signal line  308  and the second transmitter signal line  322 . A set of transmit low pass filters  314  and  328  converts the drive signals output from the digital potentiometers  312  and  326  into an analogy signals with desired frequency. The analog signals are then amplified by a set of transmit amplifier  316  and  330 , respective outputs of which are input to a set bank of matching capacitors  318  and  332  that in combination with the first and second antenna loops  302  and  304  of the AM EAS transceiver antenna system  204  form an LC circuit that is tuned to resonate at a desired resonant frequency (e.g., 58 KHz), to generate AM acousto magnetic pulses. Accordingly, the first bank of capacitors  318  is coupled to a first end  380  of the first inductor loop  302 , with a second end of the first inductor loop  302  coupled with ground  342 . The second bank of capacitors  332  is coupled to a first end  382  of the second inductor loop  304 , with a second end of the second inductor loop  302  coupled with ground  342 . 
     As indicated above, the transceiver controller module  218  has a transmitter mode of operation and a receiver mode of operation, which enable the EAS antenna system  204  to transmit signals at desired resonating frequency, and receive EAS signals at a desired resonating frequency. As further indicated above, the transceiver controller module  218  switches to the receiver mode of operation after every single transmission within a specified period (or a window of time). This time period allows the transmission of a single to be completed prior to a delay period and switching to the receiver mode of operation. However, depending on the quality (or Q factor) of the LC resonating circuit (the inductor loops  302  or  304  and the respective bank of capacitors  318  or  332 ), the frequency of oscillation between the inductor loop ( 302  or  304 ) and the respective bank of capacitors ( 318  or  332 ) may have a longer duration than the specified period required for switching from transmitter mode of operation to a receiver mode of operation. Accordingly, the transceiver controller module  218  includes a set of switch mechanisms  336  and  340  that when closed, in conjunction with respective resistors  338  and  343 , eliminate further resonance of the EAS antenna system  204  during transmitter mode of operation and thereby, prevent further induced oscillation in the EAS antenna system  204  caused by an AM pulse transmissions. In other words, the switches  336  and  340  when closed, do not allow further transmission of any legacy resonance (“ring down signal”) to extend beyond the allotted transmission time and into the delay period prior to the transceiver controller module  218  switching to the receiver mode of operation. 
     As further indicated above, in the receiver mode of operation, the transceiver controller module  218  receives EAS signals of EAS tags  110  that may be within the POS EAS surveillance zone  208  through both the first and second inductor coils  302  and  304  of the transceiver antenna  204 . The received EAS signals (indicated at  320  and  334  are amplified (via amplifiers  344  and  346 ), filtered (via band-pass filters  348  and  350 ), multiplexed (via a multiplexer  352 ), and amplified (via a second amplifier set  354  and  356 ), and input to an A/D converter of the CPU  306  for processing the received EAS signals. The processing of the received EAS signals by the CPU  306  is similar in the manner that is fully disclosed and described in the U.S. Patent Application Publication 2011/0304458 to Sayegh et al., the entire disclosure of which is expressly incorporated by reference herein. 
       FIG. 4A  is an exemplary illustration of the signal processing of the received signals from the amplifiers  354 / 356  by the CPU  306 . As has been described above, the transmitter field phase relationship for the transmitting antennas of the acousto-magnetic EAS system  224  is selected during the installation process and maintained substantially constant thereafter during operation. As is well-known, at least theoretically, it is possible for a tag or a marker to pass through a surveillance zone that is generated as a result of transmitted signal with constant phase and not be detected due to the tag orientation within the surveillance zone. Therefore, theoretically, the possibility exists that a tag or marker may not be detected due to its orientation within a surveillance zone that is generated or created from a substantially constant phase signal and hence, resulting in “detection holes” within the surveillance zone. The signal processing by the CPU  306  illustrated in  FIG. 4A  obviates the possible occurrence of an undetected tag within the surveillance zone that is generated by a signal with a constant phase. The CPU  306  signal processing illustrated in  FIG. 4A  includes manipulation of digitized signal values input from the dual output channel of the voltage control amplifier  354 / 356  to compute in-phase and out of phase relationship between the received signals from the receiver antenna loops of a receiver pedestal to thereby detect any tag orientation and eliminate possible detection holes within the surveillance zone. 
     As illustrated  FIG. 4A , the CPU  306  includes Analog-to-Digital (A/D) converts  441  and  443  that convert analog signals from the dual output channel of the voltage control amplifier  354 / 356  to digital signals for further signal processing. The digitized signals are then simultaneously sampled by respective sampler unit  445  for first inductor coil (loop  302 ) and sampler unit  447  for the second inductor coil (loop  304 ). The sampling rate is at about N times the frequency of operation of the antennas per unit of time. For example, for most acousto-magnetic EAS systems the frequency of operation of transmitted signals is about 58 KHz. Therefore, in this exemplary non-limiting instance, the sample rate N would be 4×58 KHz or 232 Kilo-samples per second or 232,000 samples per second. The CPU  306  then stores M number of such samples into the respective antenna array samples  449  and  451 . That is, M digitized sampled signals for first inductor coil (loop  302 ) from the sampler  445  are stored in the antenna array sample  449 , and M digitized sampled signals for second inductor coil (loop  304 ) from the sampler  447  are stored in the antenna array sample  451 . The selection of the number of samples M to be stored depends on the array size selected. That is, the numeric value of M is commensurate with the size of the array. In this non-limiting exemplary instance, the sizes of the arrays  449  and  451  are 512 units and hence, 512 samples are selected from each sampler, and stored in the respective antenna array samples  449  and  451 . The CPU  306  then adds those M samples from the arrays  449  and  451  via an ADDER  453  to compute in phase signal values (the so-called “O” configuration) and stores values in the in-phase or “O” configuration array  457 , and subtracts the same via a SUBTRACT function  455  to compute the out of phase signal values (the so-called “8” configuration) and stores the results in the out of phase or “8” configuration array  459 . The computed in-phase and out of phase relationship between the received signals from the receiver antenna loops of a receiver pedestal are then used (analyzed) to determine a detection of a tag or marker (regardless of any tag orientation), eliminating any possible detection holes within the surveillance zone. 
     As will be apparent from the flowcharts illustrated in  FIGS. 4B and 4C  and the timing and signal analysis graphs of  FIGS. 4D to 4I  (all of which are described in detail below), the operational or functional acts of the CPU  306  to sample, store, and compute the “O” and “8” configurations on received data is performed twice at predetermined reserved time periods. That is, sampling, storage, and computing is performed at a first predetermined reserved time when CPU  306  is timed or clocked to receive data from the tag, which is exemplarily illustrated at the predetermined reserved time period t 3  shown in  FIG. 4D , with the actual operational functional act exemplarily shown in  FIG. 4B  as the operational act  454 . The second predetermined reserved time for the second sampling, storage, and computing is performed when the CPU  306  is timed or clocked to receive ambient or background noise (i.e., the CPU  306  is not expected to receive tag signal at this reserved time period), which is exemplarily illustrated at the predetermined reserved time period t 5  shown in  FIG. 4D , with the actual operational functional act exemplarily shown in  FIG. 4B  as the operational act  460 . Stated otherwise, the results of the operational act  454  are data for “O” and “8” configurations in the respective arrays  457  and  459  that relate to the data from a tag (timed to receive at t 3 ), and the results of the operational act  460  are data for “O” and “8” configurations in the respective arrays  457  and  459  from environmental signal (timed to receive at t 5 ). It should be noted that it is only for clarity and convince that only a limited number of arrays are illustrated. In fact, the present invention uses a large number of arrays (or a plurality of arrays) to store all signal information for the many cycles of the operational acts  456  and  462  (including operational acts  465  and  467 ) in  FIG. 4B . In addition, as illustrated in  FIG. 3A , the CPU  306  includes one or more internal and external memory to store further signaling and programming information. Non-limiting examples of such memory may include the illustrated Random Access Memory RAM or Electrically Erasable Programmable Read-Only Memory EEPROM  441 . 
       FIGS. 4B and 4C  are exemplary illustrations of the flowcharts of the operational functional acts of the computer or CPU  306  in accordance with the present invention, and  FIGS. 4D to 4I  are exemplary illustrations of the timing and signal analysis graphs of the acousto-magnetic EAS system of the present invention. As is well known, in general, most acousto-magnetic EAS systems operate at a frequency of about 58.4 KHz, and transmit signals in bursts. Conventional acousto-magnetic EAS systems transmit signals at a normal rate but double the transmission rate (double the number of signal bursts) upon detection of a tag. The present invention transmits signals at a substantially constant burst rate “P.” That is, the present invention transmits signals at “P” bursts per unit of time and maintains this transmission rate. Accordingly, as illustrated in  FIG. 4B , at the operational act  463 , the CPU  306  is prepared by setting the transmission signal burst count to some value “P.” In this non-limiting exemplary instance, the Burst Count may be set to transmit signals at P=6 burst pulses, with each burst pulse having 1.6 millisecond (ms) duration, and with each burst pulse separated by 11.1 ms (if power supply frequency is at 60 Hz). In other words, in the non-limiting exemplary instance where Burst Count P is set to equal the numeric value 6 at the operational act  463 , the operational acts  450  to  462  (including  465  and  467 ) are executed six times, prior to the commencement of the execution of the operational acts of  464  to  474  that are illustrated in  FIG. 4C . After “P” execution cycles of operational acts  450  to  462  (including  465  and  467 ) shown in  FIG. 4B , the operational acts  464  to  474  (shown in  FIG. 4C ) are then executed. In this non-limiting exemplary instance, the CPU  306  is allotted about 20 ms to execute the operational acts  464  to  474  (shown in  FIG. 4C ). Stated other wise, the CPU  306  of the system  400  of the present invention waits for about 20 ms before resetting the Bust Count P to a selected value. Accordingly, unlike the conventional acousto-magnetic systems that vary the rate of transmission signal bursts based upon the type of received signal, the present invention sets and maintains the rate of transmission signal bursts. As stated above, all data gathered throughout each of the “P” cycles are stored in a plurality of arrays (or memory), such as those illustrated in  FIG. 4A  (only two arrays are illustrated for clarity). 
     As best illustrated in  FIGS. 4B and 4C, and 4D , at the operational act  450  the input lines at exemplary phase lines A, B, and C illustrated in  FIG. 4D  are synchronized, and as part of the synchronization, the transmission from the transmitter TX 1  is performed at the exemplary zero-crossing of the phase lines. It should be noted that synchronization of the transmission signals are done so to not interfere with one another and for appropriate reading of tag and noise signals. For example, a first system in one physical location functioning on phase line A must be synchronized such that no other signal is transmitted simultaneously by a second, different system functioning (for example) on phase line C at another, nearby physical location. As a further example, the start of a transmission of the signal pulse is synchronized to start at a zero-crossing, for example, at the start of time T 1  for the duration of t 1  for phase line A, or end of time t 5  (for another system on phase line C). Once all timings for all signals are synchronized, at the operational act  452  a first signal pulse burst Tx with duration of t 1  is transmitted ( FIGS. 4G and 4H ) at time T 1  via the transmitter pedestal TX 1 . It should be noted that for systems that require a further delay in synchronization, after the operational act  452 , an optional delay of Δ1 can be interjected so that t 1  does not commence at the exemplary start of the zero-crossing, but is shifted (delayed) by some time Δ1. 
     All times are described as follows in relation to  FIGS. 4D to 4I . As best illustrated in  FIG. 4D , t 1  is the pulse duration (operational act  452  in  FIG. 4B ) and t 2  is the settlement phase or period of the pulse (operational act  405  in  FIG. 4B ). The time period t 3  is reserved for the microprocessor  306  to wait and listen and detect to receive signals from a tag that may be within a surveillance zone of the acousto-magnetic EAS system  224  (operational act  454  in  FIG. 4B ). Time duration t 4  is reserved for another system such as that shown on phase C to send its own pulse (operational act  458  in  FIG. 4B ), and t 5  is the time reserved for the microprocessor  306  to wait and listen and detect the environmental noise (operational act  460  in  FIG. 4B ). 
       FIG. 4E  illustrates the signaling for the acousto-magnetic EAS system with no tag signal transmission. As illustrated, there is no tag signal at t 3 .  FIG. 4F  illustrates the same, but includes a tag response, which is within the time period t 3 .  FIG. 4G  is an exemplary signaling illustration for two independent acousto-magnetic EAS systems  224 , which due to synchronization, start sending out signals at zero-crossing and at times t 1  and t 4 , with no tag transmission (no tag is present).  FIG. 4H  is an exemplary signaling illustration as shown in  FIG. 4G , but includes a tag response from within system  1 , at time period t 3  on phase line A. Finally,  FIG. 4I  is an exemplary signaling illustration that shows system operating with a tag (tag output at time t 3 ), which is also jammed by a jammer. As illustrated, the jammer signal is similar to that of a tag signal, but is continuous in time rather than in bursts. It should be noted that a jammer signal will (at the very least) be detected at time t 3  (where the system is expecting a signal from the tag) and at time t 5 , which is reserved for detection of background or ambient signal only. Accordingly, the jammer signal is a continuous signal, is not in bursts, and is not synchronized with the timed sequence of events associated with the entire system, making it possible for its detection. It should be noted that all times t 1 , t 2 , t 3 , . . . to are programmable and may be changed, this also applies to all signals and signal features or characteristics (e.g., start and end of pulses, number of pluses, pulse width, pulse strength, duration, amplitude, period, frequency, phase, repetition, etc.). 
     Referring back to  FIG. 4A  (and in combination with  FIGS. 4D to 4I ), after the operational act  452 , at the operational act  405 , the microcomputer  306  waits for a duration of t 2  for the pulse that commenced at t 1  to have time to settle. Thereafter, at the operational act  454  the received signals are sampled (described in detail in relation to  FIG. 4A ). That is, this is the duration t 3  where the received signal may be a signal from a tag or a jammer unit. At the operational act  456 , the microcomputer  306  stores the sampled results (tag or jammer signals), and waits at operational act  458 . This wait is for a duration t 4 , which provides sufficient time for other system to transmit their respective pulses. At operational act  460 , the microcomputer samples further data, but this time for noise (or possibly jammer signal) from the receiver antenna for a duration t 5 , and stores the received data at the operational act  462  (described in detail in relation to  FIG. 4D ). The above-described processing operational functions are repeated “P” times in accordance with an exemplary counter mechanism control  463 ,  465 , and  467 . 
     At operational act  464 , all signals stored are filtered and at operational act  466  they are analyzed. At operational act  468 , it is determined if a matching alarm tag criteria is met. That is, if a possible tag signal was picked up at time duration t 3  at the operational act  454 . If it is determined that no tag signal was received, then it is determined at the operational act  470  if a jammer signal was received. In other words, was a jammer signal picked up at the operational act  454  (duration t 3 ) and/or the operational act  460  (duration t 5 ). Stated otherwise, at the operational act  470  it is determined if a match for jammer alarm criteria exist. As described above in relation to  FIG. 4L , this can be the detection of continuous signal at time t 3  and time t 5 , where the system is expecting a signal burst from the tag at time t 3  and at time t 5 , where the system is listening for noise. Accordingly, the operational act  472  is executed where an alarm is sound and the jammer information is forwarded to a computer (if the computer has requested such information, which is determined at operational act  474 .) If it is determined that a tag signal was received (at operational act  468 ) or a jammer signal is detected (at the operational act  470 ), an alarm is triggered at operational act  472 , and communicated with an outside computer. 
     Although the invention has been described in considerable detail in language specific to structural features and or method acts, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as exemplary preferred forms of implementing the claimed invention. Stated otherwise, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. Therefore, while exemplary illustrative embodiments of the invention have been described, numerous variations and alternative embodiments will occur to those skilled in the art. Such variations and alternate embodiments are contemplated, and can be made without departing from the spirit and scope of the invention. 
     It should further be noted that throughout the entire disclosure, the labels such as left, right, front, back, top, bottom, forward, reverse, clockwise, counter clockwise, up, down, or other similar terms such as upper, lower, aft, fore, vertical, horizontal, oblique, proximal, distal, parallel, perpendicular, transverse, longitudinal, etc. have been used for convenience purposes only and are not intended to imply any particular fixed direction or orientation. Instead, they are used to reflect relative locations and/or directions/orientations between various portions of an object. 
     In addition, reference to “first,” “second,” “third,” and etc. members throughout the disclosure (and in particular, claims) is not used to show a sequence, an order, a serial, and or numerical limitation but instead is used to distinguish or identify the various members of the group. 
     In addition, any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. Section 112, Paragraph 6. In particular, the use of “step of,” “act of,” “operation of,” or “operational act of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. 112, Paragraph 6.