Metal detection floor mono antenna

Abstract

A detection system for detecting EAS marker shielding material includes transceiver configured to generate an interrogation signal. The pedestal includes transmitter and receiver coils coupled to the transceiver. The transmitter coil generates an electromagnetic field across a detection region based on the interrogation signal. The receiver coil detects the electromagnetic field, which induces a reply signal in the receiver coil. The reply signal is sent to the transceiver. The reply signal changes in response to a disturbance of the electromagnetic field indicative of the presence of EAS marker shielding passing through the detection region.

Description

PCT PATENT APPLICATIONInventor: Verner FalkenbergDocket No.: 44591-01953TITLEMETAL DETECTION FLOOR MONO ANTENNACROSS REFERENCE TO RELATED APPLICATIONS

[0001] The application claims the priority benefit of US Prov. Pat. App. No. 63 / 534,412, filed August 24, 2023, and entitled “METAL DETECTION FLOOR MONO ANTENNA”, which is incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates to an antenna system for deterring theft, more particularly, a metal detection system configured to detect electronic article surveillance (“EAS”) marker shielding material.BACKGROUND

[0002] Many merchants utilize EAS systems to prevent shoplifting. Such systems traditionally employ antennas (e.g., a transmitter antenna and a receiver antenna) to detect EAS markers or tags (e.g., RFID tags, tags with oscillating circuits or chips) affixed to or embedded in merchandise sold by the merchant. Traditionally, EAS antennas are positioned at opposite sides of a store entrance or exit and are configured to actuate an alarm upon detecting EAS tagged merchandise passing through a detection region between the antennas. However, the efficacy of EAS detection is compromised when a thief utilizes EAS marker shielding material (e.g., a metal foil) to shield theE AS tag from detection, for example, by placing the E AS -tagged item in a metal-foil lined shopping bag.

[0003] In view of the foregoing, some retailers utilize metal detection systems in conjunction with EAS systems to detect the presence of EAS marker shielding materials. Such systems typically employ a transmitter and receiver antenna disposed in vertical pedestals placed on opposite sides of a detection region, e.g., a store’s entrance or exit. However, such metal detection systems are conspicuous, alerting a thief to rely on other means to misappropriate merchandise (e.g., an EAS detacher, etc.). In addition, operating two separate antennas can be very costly, particularly from an installation cost perspective, which requires retailers to make provisions (e.g., routing additional utility lines on opposing sides of a detection region, the labor cost for securing each antenna to a floor, etc.). Moreover, such systems require considerable floor space and / or may diminish the aesthetic appeal of a business.SUMMARY

[0001] The following presents a summary of this disclosure to provide a basic understanding of some aspects. This summary is intended to neither identify key or critical elements nor define any limitations of embodiments or claims. This summary may provide a simplified overview of some aspects that may be described in greater detail in other portions of this disclosure. Furthermore, any of the describe aspects may be isolated or combined with other described aspects without limitation.

[0003] A metal detection system that: optimizes floor space; decreases the overall installation cost; maintains the aesthetic appeal of a business; and is inconspicuous to thieves is described below. The metal detection system includes a transmitter antenna (coil) and a receiver antenna (coil) that may be arranged within or beneath the groundsurface to detect EAS marker shielding material passing through a detection region located above the ground surface.

[0004] In accordance with one aspect, there is provided a metal detection system for detecting EAS marker shielding material. The metal detection system includes a transceiver configured to generate an interrogation signal. A transmitter coil is coupled to the transceiver and is configured to transmit the interrogation signal across a detection region proximate to the metal detection system. A receiver coil is coupled to the transceiver and is configured to detect the interrogation signal and send a reply signal to the transceiver indicating a status of the interrogation signal.

[0005] In accordance with another aspect, there is provided a detection system for detecting EAS metal shielding material. The detection system includes a pedestal with a transmitter coil and a receiver coil. The transmitter coil circumscribes the receiver coil and is disposed in a substantially common plane therewith. The transmitter coil is configured to transmit an interrogation signal to a detection region proximate to the pedestal. The receiver coil is configured to detect a status of the interrogation signal. A controller is operatively connected to the transmitter coil and to the receiver coil and is configured to actuate at least one of an audible alarm and / or a visual alarm when the receiver coil detects a disturbance to the interrogation signal.

[0006] In one aspect of the invention, a metal detection system for detecting electronic article surveillance (EAS) marker shielding material comprises, a transceiver configured to generate an interrogation signal; and a transmitter coil coupled to the transceiver and configured to generate an electromagnetic field across a detection region based on the interrogation signal and induce a reply signal in a receiver coil. The receiver coil coupled to the transceiver and configured to send the reply signal to the transceiver, wherein the reply signal changes when the EAS shielding material ispresent in the detection region, such that the transceiver determines the presence of EAS shielding material in the detection region based on the reply signal, wherein the transmitter coil and the receiver coil are coupled and substantially concentric, wherein the transmitter coil and the receiver coil are predominantly disposed in a common plane or and predominately disposed on substantially parallel planes.

[0007] In another aspect of the invention, the detection region is proximate to the metal detection system. The transmitter coil and receiver coil are: (1) above or in a ceiling, and wherein the substantially common plane or substantially parallel planes are substantially parallel to the ceiling; and / or (2) below or in a ground surface, and wherein the substantially common plane or the substantially parallel planes are substantially parallel to the ground surface.

[0008] In another aspect of the invention, the metal detection system further comprises an RX balance control coil coupled to the transceiver and configured to adjust the strength of the reply signal transmitted from the receiver coil to the transceiver.

[0009] In another aspect of the invention, the receiver coil is rotatable with respect to the transmitter coil while remaining substantially concentric and located on the substantially common plane or the substantially parallel planes.

[0010] In another aspect of the invention, the detection system further includes a pedestal horizontally oriented and substantially parallel with the ground surface, wherein the transmitter coil and the receiver coil are attached to the pedestal.

[0011] In another aspect of the invention, the metal detection system further includes a ferrite tile disposed beneath the pedestal and configured to shield the detection system from electromagnetic interference.

[0012] In another aspect of the invention, the interrogation signal is a high frequency, AC waveform engendering (inducing) the electromagnetic field to the detection region.

[0013] In another aspect of the invention, the transceiver includes a controller configured to convert the reply signal to operating data indicating an operating status of the metal detection system.

[0014] In another aspect of the invention, the metal detection system is operatively connected to a host device, said host device being operable to adjust the reply signal transmitted from the receiver coil.

[0015] In another aspect of the invention, the metal detection system further comprises a controller operatively connected to the transceiver, said controller being configured to actuate at least one or more of an audible alarm, a light, and / or transmit a message to a host device and / or a remote device operatively connected to the controller.

[0016] In yet another aspect, a detection system for detecting electronic article surveillance (EAS) marker shielding material comprises, a detection pedestal including a transmitter coil and a receiver coil. The transmitter coil and the receiver coil being substantially concentric and being disposed in a substantially common plane or on substantially parallel planes therewith. The transmitter coil being configured to generate an electromagnetic field to a detection region proximate the detection pedestal based on an interrogation signal. The receiver coil is configured to generate a reply signal that changes in response to a disturbance in the electromagnetic field indicative of a presence of EAS metal shielding material in the detection region. The system further includes a controller operatively connected to the detection pedestal. The controller being configured to actuate at least one of an audible alarm and / or a visual alarm when the receiver coil generates the reply signal indicative of the presence of the EAS marker shielding material passing through the detection region.

[0017] In another aspect of the invention, the detection pedestal further comprises an RX balance control coil configured to adjust a strength of the reply signal transmitted from the receiver coil.

[0018] In another aspect of the invention, the detection system further comprises a host device operatively connected to the controller. The host device being operable to adjust the strength of the reply signal transmitted from the receiver coil.

[0019] In another aspect of the invention, the host device includes a user interface operable to adjust the strength of the interrogation signal and / or the reply signal.

[0020] In another aspect of the invention, the plane or planes are substantially parallel to a vertical wall.

[0021] In yet another aspect of the invention, a detection system for detecting electronic article surveillance (EAS) marker shielding material includes, a controller in communication with a transmitter coil and a receiver coil, wherein the transmitter coil and the receiver coil are coupled, substantially concentric, and predominately disposed in a substantially common plane or substantially parallel planes. The controller having a processor and memory, the memory storing executable code when executed by the processor performs actions including: receiving operating settings from a user; generating an interrogation signal in said transmitter coil, thereby causing the transmitter coil to generate an electromagnetic field to a detection region. The actions further including receiving a reply signal from the receiver coil, wherein the reply signal is induced by said electromagnetic field, wherein the reply signal changes in response to a disturbance in the electromagnetic field indicative of a presence of EAS marker shielding material in the detection region. The actions further including determining whether EAS marker shielding material is present in the detection region using operating data comprised of the reply signal. The actions further including, outputtingdetection system status to a user, wherein the detection system status is comprised of generating an alarm when EAS marker shield material is present in the detection region. The detection region is proximate to the detection system. The transmitter coil and receiver coil are: (1) above or in a ceiling, and wherein the substantially common plane or substantially parallel planes are substantially parallel to the ceiling, and / or (2) below or in a ground surface, and wherein the substantially common plane or substantially parallel planes are substantially parallel to the ground surface.

[0022] In another aspect of the invention, the detection system further comprises an RX balance control coil coupled to the transceiver and configured to adjust a strength of the reply signal transmitted from the receiver coil to the transceiver.

[0023] In another aspect of the invention, generating an alarm is comprised of actuating at least one or more of an audible alarm, a light, and / or transmitting a message to a host device and / or a remote device operatively connected to the controller.

[0024] In another aspect of the invention, the transmitter coil is rotatable with respect to the receiver coil, while remaining substantially concentric and located on the substantially common plane or the substantially parallel planes.

[0025] In another aspect of the invention, the operating settings comprises at least one of a signal strength of the RX balance coil, a strength of the electromagnetic field, and / or a frequency of the interrogation signal. The operating data is outputted to the user, the operating data comprising at least one of a signal strength of the reply signal, a noise level of the reply signal, and / or a metal detection signal.DESCRIPTION OF THE DRAWINGS

[0026] The above and other features, examples and advantages of aspects or examples of the present disclosure are better understood when the following detailed description is read with reference to the accompanying drawings, wherein,

[0027] FIG. 1 is a perspective view of a conventional metal detection system with a transmitter antenna and a receiver antenna spaced apart and defining a detection region therebetween;

[0028] FIG. 2A is an exploded, perspective view of an example metal detection system in accordance with the present disclosure shown in relation to a ground surface;

[0029] FIG. 2B is a top view of the example metal detection system of FIG. 2 A;

[0030] FIG. 2C is a top view of the transmitter coil and receiver coil, with the receiver coil being rotated 90 degrees with respect to the transmitter coil, when compared to the coil configuration shown in FIG. 2B, in accordance with the present disclosure;

[0031] FIG. 3 is a schematic illustration of an example antenna printed circuit board (PCB) in accordance with the present disclosure;

[0032] FIG. 4A is a block diagram view of another example metal detection system in accordance with the present disclosure;

[0033] FIG. 4B is a block diagram view of a controller PCB of the controller in accordance with the present disclosure;

[0034] FIG. 5 is an exploded, perspective view of a pair of metal detection systems in accordance with the present disclosure;

[0035] FIG. 6 is an illustration of an example user interface for a metal detection system in accordance with the present disclosure;

[0036] FIG. 7 is an illustration of another example user interface for a metal detection system in accordance with the present disclosure;

[0037] FIG. 8 is a top view of another example metal detection system in accordance with the present disclosure; and

[0038] FIG. 9 is a flow chart of a method of using the detection system in accordance with the present disclosure.DETAILED DESCRIPTION

[0039] Reference will now be made in detail to embodiments of the present teachings, examples of which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized and structural and functional changes may be made without departing from the scope of the present teachings. Moreover, features of the embodiments may be combined, switched, or altered without departing from the scope of the present teachings, e.g., features of each disclosed embodiment may be combined, switched, or replaced with features of the other disclosed embodiments. As such, the following description is presented by way of illustration and does not limit the various alternatives and modifications that may be made to the illustrated embodiments and still be within the spirit and scope of the present teachings.

[0040] As used herein, the words “example” and “exemplary” mean an instance, or illustration. The words “example” or “exemplary” do not indicate a key or preferred aspect or embodiment. The word “or” is intended to be inclusive rather an exclusive, unless context suggests otherwise. As an example, the phrase “A employs B or C,” includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C). As another matter, the articles “a” and “an” are generally intended to mean “one or more” unless context suggests otherwise.

[0041] “Logic” refers to any information and / or data that may be applied to direct the operation of a processor. Logic may be formed from instruction signals stored in amemory (e.g., a non-transitory memory). Software is one example of logic. In another aspect, logic may include hardware, alone or in combination with software. For instance, logic may include digital and / or analog hardware circuits, such as hardware circuits comprising logical gates (e.g., AND, OR, XOR, NAND, NOR, and other logical operations). Furthermore, logic may be programmed and / or include aspects of various devices and is not limited to a single device.

[0042] The term “EAS marker” may encompass security tags comprising a circuit, for example, an oscillating circuit containing a coil and / or a capacitor, or it may embody an integrated circuit (e.g., a chip) designed to be detected by an electronic article surveillance system. Alternatively, it may embody a Radio Frequency Identification Tag (RFID).

[0043] The terms “substantially,” “predominantly,” “about,” and variations thereof are intended to note that the described features are equal or approximately equal to a value or characteristic, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors. For example, the term “substantially rectangular” is intended to denote structure that is rectangular or approximately rectangular. As another example, the terms “substantially,” “predominately,” “about,” and variations thereof can denote values or characteristics that are exact or within 15% of exact, for example within 10% of exact, or within 3% of exact.

[0044] Electronic article surveillance (“EAS”) systems are commonly employed to detect the shoplifting of merchandise from retail stores. EAS systems typically include EAS antennas that detect EAS markers (e.g., tags or labels) affixed to or embedded in merchandise. Some shoplifters utilize EAS marker shielding material (e.g., a metal or tin foil) to evade detection, for example, by placing EAS-tagged merchandise in ashopping bag internally lined with EAS marker shielding material to inhibit the EAS marker from being detected.

[0045] In view of the foregoing, some retailers utilize a metal detection system 10 (FIG.1) in conjunction with an EAS system to detect EAS marker shielding material. A typical metal detection system 10 includes a transmitter antenna 12 and a receiver antenna 14. The transmitter and receiver antennas 12 and 14 are commonly mounted to upstanding pedestals spaced apart, for example, on opposite sides of a detection region corresponding with a store’s entrance or exit. The transmitter antenna 12 sends an interrogation signal that is detected by the receiver antenna 14. When EAS marker shielding material passes between the antennas 12 and 14 (e.g., through the detection region), the receiver antenna 14 will detect a disturbance in the interrogation signal sent by the transmitter antenna 12, thereby actuating an alarm (e.g., an audible alarm and / or lighting) or alerting store employees (e.g., via a coded message) of a potential shoplifter entering the store.

[0046] Because such metal detection systems are conspicuous, many thieves resort to other shoplifting means, for example, detachers to physically remove EAS markers from merchandise (e.g., while in a changing room) before exiting the store. In addition, such metal detection systems require significant floor space and are often unsightly, detracting from a store’s aesthetic appeal.

[0047] As described herein, an exemplary embodiment of a metal detection system includes a detection pedestal with a transmitter antenna and a receiver antenna attached thereto and integrated as a low-profile assembly. The detection pedestal may be arranged below a ground surface of a detection region thereabove. The transmitter antenna and the receiver antenna respectively comprise transmitter and receiver coils. The transmitter coil is configured to sends an electromagnetic field induced by theinterrogation signal (i.e., an electromagnetic field) across a detection region, and the receiver coil is configured to detect the electromagnetic field by producing a reply signal induced by the electromagnetic field. The reply signal indicating a status of the electromagnetic field. In particular, the receiver coil is configured to detect disturbances in the electromagnetic field generated by the transmitter coil when EAS marker shielding material (e.g., a tin foil / metal-lined bag) passes through the detection region.

[0048] In some exemplary embodiment, the transmitter coil may comprise a loop that circumscribes the receiver coil, and the receiver coil may embody a figure eight-shaped loop. In some exemplary embodiments, the transmitter coil and receiver coil comprise loops that may overlap and intersect each other, when viewed overhead. In some exemplary embodiments, the transmitter coil and the receiver coil may be disposed in a common plane. In some exemplary embodiments, the metal detection system may include a controller operatively connected to the transmitter coil and the receiver coil. The controller may be configured to receive operating data corresponding to the reply signal generated by the receiver coil. In some exemplary embodiments, the controller may be operatively connected to at least one of an audible alarm, a visual alarm, a host device and / or a user-device. In an exemplary embodiment, the host device may be a web-configurator and the user-device may be an employee’s mobile phone.

[0049] A transceiver may be comprised of one or more antenna PCBs, and may be arranged between the detection pedestal and the controller. The transceiver may also be coupled to the transmitter and receiver coils. The transceiver generates the interrogation signal, and receives a reply signal from the receiver coil. In some exemplary embodiments, the interrogation signal may be a high-frequency AC waveform, for example, a sine wave transmitted at a frequency between about 20 kHz and 30 kHz. In some exemplary embodiments, the transceiver may include a processorconfigured to convert the reply signal transmitted from the receiver coil into the operating data.

[0050] In some exemplary embodiments, a host device is operatively connected to the controller and is operable to tune the metal detection system, for example, to increase or decrease the strength of a signal (e.g., to minimize signal distortion). In some exemplary embodiments, one or more metal detection systems may be operatively connected to the controller, for example, one beneath a detection region and one above the detection region to enhance detection. In some exemplary embodiments, the metal detection system may be located in the floor, when the metal detection system is located within or beneath the detection region. Further, in some exemplary embodiments, the metal detection system may be located within or beneath the ceiling, when the metal detection system is located above the detection region.

[0051] In some exemplary embodiments, one or more ferrite tiles may be disposed beneath the detection pedestal to shield the interrogation signal from interference, such as to shield the electromagnetic field of the interrogation signal from interference.

[0052] Referring to FIGS. 2 A and 2B, a first exemplary embodiment of a metal detection system 200 in accordance with the present disclosure is shown. The metal detection system 200 includes a pedestal 240 with a transmitter coil 260 (also referred to as a “TX coil” or “TX loop”) and a receiver coil 270 (also referred to as a “RX coil” or “RX loop”) attached thereto. In general, the metal detection system 200 is configured to detect EAS marker shielding material 231 (e.g., a metal foil-lined bag) in a detection region (FIG. 2A) above a ground surface 233 (e.g., the floor of a retail shopping entrance). In this exemplary embodiment, the metal detection system 200 is configured to perform the foregoing detection from a location in or beneath the ground surface 233(e.g. in or beneath the floor) such that the metal detection system 200 is not conspicuous to would-be shoplifters.

[0053] In the illustrated embodiment, the pedestal 240 is horizontally oriented such that an upper and a lower surface thereof is substantially parallel to the ground surface, with the lower surface being on the opposite face of the pedastal 240 from the upper surface, spaced apart from the upper surface, and substantially parallel to the upper surface. In some embodiments, the pedestal 240 embodies a thermoplastic (e.g., Poly (methyl methacrylate)), waterproof enclosure for enclosing the transmitter and receiver coils 260 and 270 therein. It is also contemplated that the pedestal 240 may be made from another rigid material, for example, wood or glass.

[0054] The transmitter and receiver coils 260 and 270 may include hookup wire for transmitting an AC current therethrough. Referring to exemplary embodiment shown in FIG. 2B, the transmitter coil 260 may be an elongated loop that substantially circumscribes the receiver coil 270. In the illustrated embodiment, the transmitter coil 260 and the receiver coil 270 may be predominately disposed in a common plane defined by the x-axis and the y-axis. In some exemplary embodiments, the separation distance between the transmitter coil 260 and receiver coil 270 may be about 6 cm. Stated alternatively, the gap (separation distance) between the transmitter coil 260 and receiver coil 270 in the plane defined by the x-axis and y-axis may be about 6 cm. In other exemplary embodiments, a person having ordinary skill in the art may choose to use another separation distance between the transmitter coil 260 and receiver coil 270. This aspect of the present disclosure advantageously gives the metal detection system a low-profile, decreasing installation space requirements and enabling the metal detection system to be placed in a manner substantially parallel to the ground surface 233, e.g., underneath or within the ground surface.

[0055] Returning to the illustrated example, the transmitter coil 260 may be arranged in a substantially rectangular configuration and electrically connected to the transceiver 280, such as by a hookup wire lead extending to the transceiver 280. It is contemplated that the transmitter coil 260 may be arranged in different non-limiting configurations, for example, in a substantially oval, circular, or square-shaped configuration.

[0056] The receiver coil 270 may be arranged in a substantially rectangular configuration and electrically connected to the transceiver 280, such as by a hookup wire lead extending to the transceiver 280. It is contemplated that in some exemplary embodiments, the receiver coil 270 may be arranged in other non-limiting configurations, for example, a substantially oval, circular, or square shaped configuration. In the illustrated exemplary embodiment in FIG. 2B, the receiver coil 270 is arranged in a figure 8-shaped configuration. This aspect of the present disclosure advantageously reduces the strength of the reply signal transmitted by the receiver coil 270, thereby reducing signal distortion and saturation of the receiver circuit in the transceiver 280, 380, wherein the amplified incoming signal is distorted (e.g., a clipped sine-wave signal). This reduced signal distortion and saturation provides better reply signal resolution at the transceiver 280, which results in better EAS marker shielding material detection ability.

[0057] Referring to FIG. 2C, one can see that in some exemplary embodiments, the receiver coil 270 may be rotated 90 degrees with respect to the transmitter coil 260 of pedestal 240, when compared to the arrangement of the receiver FIG. 2B. Thus, the transmitter coil 260 and receiver coil 270 comprise loops that overlap and intersect each other, when the transmitter coil 260 and receiver coil 270 are centered over each other and viewed overhead. Thus, the receiver coil 270 and transmitter coil 260 of the pedestal 240 may be rotated at any angle needed with respect to each other, in order todetect EAS marker shielding material. Further, the receiver coil 270 and transmitter coil 260 may be substantially concentric and located on substantially parallel planes. Further, in other embodiments, the receiver coil 270 may be rotated with respect to the transmitter coil 260.

[0058] In an exemplary embodiment, the receiver coil 270 may be a figure-eight configuration comprised of about four turns of wire. A height of the receiver coil 270 may be about 40 cm and a width of the receiver coil 270 may be about 138 cm. The transmitter coil 260 may be arranged in a rectangular configuration comprised of about two turns of wire, have a height of about 28 cm, and a width of about 150 cm. As can be seen, the transmitter coil 260 may have two long sides (150 cm) and two short sides (28 cm). In some exemplary embodiments, the first long side 260a of the transmitter coil 260 may intersect and pass through the upper loop 270a of the receiver coil 270, and the second long side 260b of the transmitter coil 260 may intersect and pass through the lower loop 270b of the receiver coil 270.

[0059] Likewise, the first short side 260c and second short side 260d of the transmitter coil 260 do not intersect the receiver coil 270. Further, the first short side 260c of the transmitter coil 260 is parallel to the first short side 270ac of the upper loop 270a and the first short side 270bc of the lower loop 270b of the receiver coil 270. The first short side 270ac of the upper loop 270a and the first short side 270bc of the lower loop 270b are closer to the first short side 260c of the transmitter coil 260, than the second short side 260d of the transmitter coil 260. Additionally, the second short side 260d of the transmitter coil 260 is parallel to the second short side 270ad of the upper loop 270a and the second short side 270bd of the lower loop 270b of the receiver coil 270. The second short side 270ad of the upper loop 270a and the second short side 270bd of the lower loop 270b are closer to the second short side 260d of the transmitter coil 260,than the first short side 260c of the transmitter coil 260. The first short side 270ac and second short side 270ad of the upper loop 270a of receiver coil 270 intersect the first long side 260a of the transmitter coil 260. Further, the first short side 270bd and second short side 270bc of the lower loop 270b of receiver coil 270 intersect the second long side 260b of the transmitter coil 260. Additionally, the first long side 260a of the transmitter coil 260 is parallel to the long side 270aa of the upper loop 270a of the receiver coil 270. The first long side 260a of the transmitter coil 260 is closer to the long side 270aa of the upper loop 270a of the receiver coil 270. Additionally, the second long side 260b of the transmitter coil 260 is parallel to the long side 270bb of the lower loop 270b of the receiver coil 270. The second long side 260b of the transmitter coil 260 is closer to the long side 270bb of the lower loop 270b of the receiver coil 270. The long side 270aa of the upper loop 270a of the receiver coil 270 is parallel to and opposite of the long side 270bb of the lower loop 270b of the receiver coil 270. The first short side 270ac and second short side 270ad of the upper loop 270 of the receiver coil 270 are parallel to and opposite of each other. The first short side 270 be and second short side 270bd of the lower loop 270b of the receiver coil 270 are parallel to and opposite of each other.

[0060] In some exemplary embodiments, the separation distance between the first long side 260a of the transmitter coil 260 and the long side 270aa of the upper loop 270a of the receiver coil 270 may be about 6 cm, the separation distance between second long side 260b of the transmitter coil 260 and the long side 270bb of the lower loop 270b of the receiver coil 270 may be about 6cm, the separation distance between the second short side 260d of the transmitter coil 260 and the second short side 270ad of the upper loop 270a of receiver coil 270 may be about 6 cm, the separation distance between the second short side 260d of the transmitter coil 260 and the second short side 270bd ofthe lower loop 270b of the receiver coil 270 may be about 6 cm, the separation distance between the first short side 260c of the transmitter coil 260 and the first short side 270ac of the upper loop 270a of the receiver coil 270 may be about 6 cm, and the separation distance between the first short side 260c of the transmitter coil 260 and the first short side 270bc of the lower loop 270b of the receiver coil 270 may be about 6 cm.

[0061] Referring to FIG. 3, the transceiver 380 may include an antenna PCB. In some embodiments, the transceiver 380 may include one or more antenna PCBs corresponding to the respective transmitter and receiver coils 260 and 270.

[0062] The transceiver 380 may include memory 381 and a processor 382 configured to generate an interrogation signal. In some exemplary embodiments, the interrogation signal may be a high-frequency AC waveform having frequency of about 17 to 30 kHz. The processor 382 may embody any suitable processing device or set of processing devices, such as, but not limited to: a processor, a microprocessor, a microcontrollerbased platform, a suitable integrated circuit, one or more field programmable gate arrays (FPGAs), and / or one or more application-specific integrated circuits (ASICs). The memory 381 may contain instructions that when executed by the processor 382 may comprise logic to generate the high frequency interrogation signal, for example, based on a DC power input supplied from an external power supply. In an exemplary embodiment, the external power supply may be a 24V DC power supply. It is contemplated that the transceiver 380 may include inverter circuitry for this purpose. The high frequency AC waveform travelling through the transmitter coil 260 (FIG. 2B) may produce an electromagnetic field (also referred to as a “TX field”) above the detection pedestal 240. In some exemplary embodiments, this TX field may be produced in the detection region 230 above the ground surface 233.

[0063] The transceiver 280 may also be configured to receive a reply signal from the receiver coil 270. The receiver coil 270 may be electromagnetically coupled to the transmitter coil 260. The reply signal may be induced in the receiver coil 270 by the TX field 232 (electromagnetic field) generated by the interrogation signal travelling through the transmitter coil 260.

[0064] In this manner, the transceiver 280 may be configured to detect a reply signal indicating a status (e.g., in real time) of the interrogation signal (i.e., the electromagnetic field, TX field). In some exemplary embodiments, the transceiver 280 may be configured to detect a reply signal indicating a status, in real time, of the electromagnetic field 232 (TX field). In particular, the transceiver 280 is configured to detect disturbances in the electromagnetic field 232 (TX field), for example, based on the presence ofEAS shielding material 231 (e.g., a metal foil-lined bag) passing through the detection region 230. In some embodiments, the processor 382 of the transceiver 280 generates a data signal based on the reply signal received from the receiver coil 270. The data signal may comprise operating data, for example, operating data indicating the presence or absence of EAS marker shielding material 231 passing through the detection region 230.

[0065] Referring to FIG. 2B, the pedestal 240 is arranged above one or one more ferrite tiles 290 configured to insulate the pedestal 240 and the transceiver 280 (and the interrogation and reply signals of the respective coils 260, 270) from electromagnetic interference, for example, due to the presence of metal disposed in or beneath the ground surface, e.g., metal or iron rebar in a concrete subfloor that may otherwise short circuit the metal detection system 200. In some embodiments, the pedestal 240 may be spaced above the ferrite tiles 290, for example, by a predetermined vertical distance. In an exemplary embodiment, this predetermined vertical distance may be about 5centimeters (as measured in a direction parallel to the z-axis of FIG. 2A). In some exemplary embodiments, plastic spacers (not shown) may be utilized to space the pedestal 240 above the ferrite tiles 290. In the illustrated embodiment, there are a plurality of ferrite tiles 290 extending beneath and surrounding a periphery of the pedestal 240. It is contemplated that a single ferrite sheet or plate may be used instead to shield the pedestal 240 from electromagnetic interference.

[0066] Referring to FIGS. 4A-B, a block diagram representation of another example of a metal detection system 400 in accordance with the present disclosure is shown. The metal detection system 400 shares similarities with the metal detection system 200 described above. Therefore, a description of similar features has been omitted for brevity, except for the differences noted below.

[0067] In this embodiment, the pedestal 440 includes an RX balance control coil 465 (also referred to as a “balance transmitter coil,” a “RX balance control loop,” or a “RX balance coil”) attached thereto and operatively connected to the transceiver 480. The balance transmitter coil 465 is configured to transmit a signal (in phase or in opposite phase) to adjust the balance of the receiver coil 470, for example, if the signal transmitted from the receiver coil 470 is too high, resulting in signal distortion due to saturation of the receiver circuit in the transceiver 470. In such embodiments, it is contemplated that the transceiver 480 may detect whether the receiver coil 470 is imbalanced (via a reply signal therefrom), and transmit this information to a controller 490 in the form of operating data (indicating that the receiver coil is imbalanced). In some exemplary embodiments, the balance transmitter coil 465 may be located in the pedestal 440. In other exemplary embodiments, the RX balance control coil may be located in the transceiver 480, instead of the pedestal 440.

[0068] Still referring to FIGS. 4A-B, the controller 490 may be operatively connected to the transceiver 480. In some embodiments, it is contemplated that the controller 490 and the transceiver 480 may form part of a single enclosure. In some embodiments, it is contemplated that the controller 490 may include the transceiver 480. In some embodiments, the controller 490 may embody a computer, wherein the computer includes a processing unit (processor) 492, a system memory (memory) 491, and a system bus for coupling system components, e.g., for coupling the processing unit to a system memory. The processing unit may be any of various commercially available processors. Dual microprocessors and other mufti-processor architectures can be employed as the processing unit. The system memory 491 may be any available media that can be accessed by the processor 492. By way of example, and not limitation, system memory 491 comprise computer storage media and communication media. Computer storage media may include volatile and nonvolatile, removable and nonremovable media implemented in any method or technology for the storage of information, such as computer readable instructions, data structures, program modules, or other data. The processing unit 492 and system memory 491 may be located on a controller PCB 495 of the controller 490.

[0069] The controller 490 can operate in a networked environment using logical, physical, and / or wireless connections to the transceiver 480 and / or to one or more of a host device 496 and / or a remote device 494, as discussed below. For this purpose, in some embodiments, the controller 490 and / or the transceiver 480 may include a communication device configured to send and receive commands, signals, and operating data via a communications network. For instance, the controller 490 and / or the transceiver 480 may include hardware (e.g., one or more controllers) to communicate over standards-based protocols / networks (e.g., GSM, UMTS, LTE,CDMA, WiMAX, etc.), satellite communications networks, and / or wireless local area networks (e.g., WiFi, Wireless Gigabit, etc.). In some examples, the controller 490 and / or the transceiver 480 may include hardware (e.g. controllers) for personal area networks (e.g., Bluetooth, ZigBee (“IEEE 802.14.4”), Near Field Communication (“NFC”, etc.) to communicatively couple the controller 490 to the transceiver 480 and / or to one or more of the remote device 494 and the host device 496.

[0070] In such embodiments, the communications network may embody a wireless network to facilitate communication (e.g., between the controller 490 and at least one of the transceiver 480, the remote device 494, and the host device 496) over a wide area network (e.g., such as a cellular network (e.g., Global System for Mobile Communications (“GSM”), Universal Mobile Telecommunications System (“UMTS”), Long Term Evolution (“LTE”), Code Division Multiple Access (“CDMA”), etc.), a satellite communication network, WiMAX (“IEEE 802.16m), etc.), and / or a location area network (e.g., IEEE 802.11 a / b / g / n / ac, etc.). In some examples, the controller 490 may be communicatively coupled to the communications network over a public network, such as the Internet; a private network, such as an intranet; or combinations thereof. Yet, in other embodiments, it is contemplated that the controller 490 may be communicatively coupled with the transceiver 480 (and / or with the remote device 494 and the host device 496) via a Bluetooth® connection or via another form of direct connection (e.g., a wired physical connection), which shall also be considered as one type of a communication network.

[0071] In one exemplary embodiment, the controller 490, via the controller PCB 495, may have a wired LAN connection 490a to the Internet, a remote device network connection 490b to the remote device 494, a USB connection 490c to host device 496,a power supply electrical connection input 490d to the power supply 498, and a communications (e.g. CAT5) connection to the transceiver 480.

[0072] The controller 490 may be configured to receive operating data from the transceiver 480 corresponding to a status of the electromagnetic field (i.e., the status of the reply signal) in real time. For example, if the electromagnetic field emanating from the transmitter coil 460 and received by the receiver coil 470 is undisturbed based on the absence of EAS marker shielding material in the detection region, then the transceiver 480 will transmit operating data to the controller 490 indicating the same (e.g., indicating that the status is “OK” because the reply signal received is as expected - the reply signal has a waveform indicating an electromagnetic field undisturbed by EAS marker shielding material). Conversely, if the electromagnetic field emanating from the transmitter coil 460 is disturbed based on the presence of EAS marker shielding material in the detection region, then the receiver coil 470 will detect this disturbance (transmitted via a reply signal to the transceiver 480 having a waveform indicating the electromagnetic field disturbed by EAS marker shielding material), at which point the transceiver 480 will convert the reply signal to operating data (e.g., via a processor thereof) that is transmitted to the controller 490 indicative of the disturbance (e.g., indicating an “ALARM” status). In this manner, the controller 490 is operatively connected to the transceiver 480 (and thus to the transmitter coil 460, the receiver coil 470, and the RX balance control coil 465). As such, the controller is 490 is configured to receive operating data conveying an operating status of the metal detection system, for instance, an “OK” status or an “ALARM” status based on the absence or presence EAS marker shielding material in the detection region. In some embodiments, the controller 490 may be operatively connected to the transceiver 480 with Cat 5 or Cat 6 communication cable for transmitting operating data therebetween.

[0073] In some embodiments, referring to FIG. 5, it is contemplated that the controller 590 may be operatively connected to multiple metal detection systems 500 and may include multiple input ports for this purpose. For example, in some embodiments, a first metal detection system 500a may be arranged below a detection region (e.g., in the ground surface or beneath the ground surface), and a second metal detection system 500b may be arranged above the detection region (e.g., in a ceiling or above the ceiling). In such embodiments, each metal detection system 500a or 500b may include a respective transceiver 580, transmitter coil 460 (FIG. 4A), receiver coil 470 (FIG. 4A), and RX balance control coil 465 (FIG. 4A). Arranging two independent metal detection systems on opposing sides of a detection region will enhance the level of metal detection. For example, a first metal detection system 500a disposed in or beneath the ground surface may be configured to detect up to about 100 cm above the ground surface. Supplementing this system 500a with one or more metal detection systems may enable the systems to detect the entire detection region between the floor and the ceiling.

[0074] Irrespective of the number of metal detection systems employed, it should be understood that one or more metal detection systems may operate in conjunction with EAS systems, including a transmitter and a receiver for detecting EAS markers. In such embodiments, it is contemplated that the EAS systems may operate on a different frequency band than the metal detection systems to avoid interference therewith.

[0075] Turning back to FIGS. 4A-B, the controller 490 may be operatively connected to a power supply 498 adapted to power the controller 490, which indirectly supplies power to the transceiver 480. It is contemplated that the controller 490 and / or the transceiver 480 may each include their own power supply, e.g., a power cable / physical connection or a rechargeable battery.

[0076] In some embodiments, the controller 490 is operatively connected to and configured to actuate a theft prevention system 493, including, but not limited to, lights (e.g., strobe lights) and / or an audible alarm (e.g., via a loud speaker) to notify employees (or the general public) of a potential shoplifting attempt. In some embodiments, the controller 490 is operatively connected to one or more remote devices 494, for instance, to mobile devices of employees of the store or building where the metal detection system 400 is being operated. In such embodiments, it is contemplated that applications (“apps”) running on the remote devices 494 may be operatively connected to the controller 490. In this manner, the controller 490 may cause an app running on a respective remote device 494 to transmit a notification (e.g., via a sound, tactile vibration) indicating a potential shoplifting attempt. It is also contemplated that the remote device 494 may be operable (e.g., via a touch screen button or slider associated with the app) to disarm the theft prevention system 200, for example, if a potential shoplifting attempt is thwarted (e.g., by loss prevention staff).

[0077] In some embodiments, the controller 490 may be operatively connected to a host device 496, e.g., a laptop, a desktop, tablet, or mobile device of an operator (e.g., a service technician) of the metal detection system 400. In such embodiments, the host device 496 may be operable to tune or otherwise adjust operating settings of the metal detection system 400. For instance, in some embodiments, the host device 496 may be operable to adjust the signal strength of the RX balance coil 465 to reduce distortion in the reply signal transmitted by the receiver coil 470. In some embodiments, the host device 496 may be operable to adjust the electromagnetic field, for example, by adjusting the frequency of the interrogation signal within the transmitter coil 460 creating the electromagnetic field in the detection zone. The electromagnetic field in the detection zone induces the reply signal in the receiver coil 470.

[0078] In some embodiments, the host device 496 may be operable to access an online tool (e.g., a web configurator) to make the foregoing adjustments. In this manner, the host device 496 may be operatively connected to the online tool via network, such as a wireless or wired network, e.g., the Internet.

[0079] Referring to FIG. 6, an example user interface 600 of an online tool for a host device 496 is shown. The user interface 600 may display operating data transmitted by the controller 490, for instance, a status of the metal detection system 200, 400 (e.g., “OK” as shown, or an “ALARM”). The user interface may 600 may also display electrical characteristics of the metal detection system 200, 400, for example, an operating voltage or the AC frequency transmitted by the respective transmitter and receiver coils. In some exemplary embodiments, user interface 600 may be hosted on controller 490 and deployed via a web interface, such that it is accessible from devices such as, but not limited to, host device 496 and / or remote device 494.

[0080] Referring to FIG. 7, another example of a user interface 700 is shown, which graphically displays operating data including the reply signal strength 720 of the receiver coil, a noise level 722 of the reply signal, and / or a metal detection signal 724 (e.g., based on the presence of EAS marker shielding material), wherein each of the foregoing examples of operating data is displayed in real time. In some embodiments, a user of the user-interface 600 may adjust the strength of one of the signals transmitted by the transceiver, for example, the signal transmitted by the RX balance coil 456 when it is desired to reduce noise or distortion in the circuit of the receiver coil 470, or when it is desired to increase or decrease the strength of the transmitter coil 460 interrogation signal. The metal detection signal 724 is an indicator of the disturbance of the electromagnetic field indicative of EAS marker shielding material present in the detection region. In some embodiments, the user interface 700 may include buttons orsliders operable to make the foregoing adjustments, e.g., by selecting the buttons or sliders with a pointing device (e.g., a mouse) and / or a touch screen.

[0081] Referring to FIG. 8, a top view of another example metal detection system 800 is shown. In this embodiment, the metal detection system 800 includes a controller 890 operatively connected to a plurality of transceivers 840, wherein each transceiver 840 is coupled to a transmitter coil 860 and a receiver coil 870 disposed on a respective, vertical pedestal 840. In this manner, it should be appreciated that the various examples of metal detection systems described herein may be arranged in different orientations, for instance, in a substantially vertical orientation that is parallel to a vertical wall, in front of a vertical wall, within a vertical wall, or behind a vertical wall (e.g., such that it is not conspicuous to thieves).

[0082] In some embodiments, one or more magnetometers 850 may be disposed about the pedestals 840. Each magnetometer 850 may be configured to detect a disturbance to the earth’s magnetic field, for example, based on the presence of a metallic shopping cart. In some embodiments, it is contemplated that a control system may be utilized to distinguish between EAS shielding material (e.g., tin foil, metal foil) and a steel shopping cart (i.e., a trolley) for this purpose, for example, the electronic control system disclosed in U.S. Patent No. 8,976,026 (assigned to the Applicant), which is incorporated by reference in its entirety.

[0083] In this manner, it should be appreciated that magnetometers 850 (e.g., for detecting a shopping cart passing through a store entrance) may be operated in conjunction with metal detection systems (for detecting EAS shielding material). It is also contemplated that the metal detection systems as disclosed herein may be utilized near door entrances, for instance, sliding or rotating doors of a retail outlet. In such embodiments, it is contemplated that a transceiver may comprise a demodulator (todemodulate a signal from the receiver coil) for this purpose, for example, as disclosed in U.S. Patent Nos. 10,796,546 and 10,832,544 (assigned to Applicant), both of which are incorporated by reference herein in their entireties.

[0084] FIG. 9 is a flow chart of a method 900 of using the detection system 400 in accordance with the present disclosure. In an exemplary embodiment, this method 900 is stored in the memory 491 of controller 490 and executed by the processor 492 of controller 490. In 905, the controller 490 receives operating settings from the user, such as through host device 496. In an exemplary embodiment, the operating settings may include at least one or more of a signal strength of the RX balance coil 465, a strength of the electromagnetic field 232, and / or a frequency of the interrogation signal.

[0085] In 910, an interrogation signal is generated in the transmitter coil 440 using the transceiver 480, such as when instructed by the controller 490. The interrogation signal inducing a electromagnetic field 232 across the detection region 230. The electromagnetic field 232 in the detection region 230 thereby inducing a reply signal in the receiver coil 470. The reply signal changes in response to a disturbance in the electromagnetic field 232 indicative of a presence of an EAS marker shielding material 231 in the detection region 230.

[0086] In 915, the transceiver 480 receives the reply signal. In 920, the reply signal is analyzed to determine the presence of EAS marker shielding material 231 in the detection region 230. The analysis of the reply signal may be performed based on the operating settings received from the user in 905 and operating data received from the transceiver 480. The analysis may be performed by the controller 490, or the controller 490 and transceiver 480.

[0087] In 925, the detection system status and operating data are outputted to the user, such as by generating an alarm when EAS marker shield material 231 is present in thedetection region 230. In an exemplary embodiment, generating an alarm may include actuating at least one or more of an audible alarm, a light, and / or transmitting a message to a host device 496 and / or a remote device 494 operatively connected to the controller 490. The operating data may also be outputted to the user via a user interface 600 700. The operating data may include one or more of a signal strength of the reply signal, a noise level of the reply signal, and / or a metal detection signal.

[0088] What has been described above includes examples of the present disclosure. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present disclosure, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present disclosure are possible. Each of the components described above may be combined or added together in any permutation to define embodiments disclosed herein. Accordingly, the present disclosure is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.

[0089] The structure, scale, and size presented in the drawings of this document are used for illustrating the contents disclosed herein and facilitating understanding and reading by persons familiar with this technology, rather than limiting the conditions for the implementation of this utility model. They are of no technical significance, and any structural modification, scale change, or size adjustment shall be covered by the technical contents disclosed herein as long as they do not affect the functions and purposes of this utility model. Meanwhile, such expressions as “above”, “below”,“left”, “right”, and “center” used in this document are for facilitating the illustration only, rather than limiting the implementation scope of this utility model. Changes or adjustments in the relative relationship is within the implementation scope of disclosed embodiments as long as there are no substantial changes to the technical contents.

Claims

CLAIMSWhat is claimed is:

1. A metal detection system for detecting electronic article surveillance (EAS) marker shielding material, the metal detection system comprising: a transceiver configured to generate an interrogation signal; and a transmitter coil coupled to the transceiver and configured to generate an electromagnetic field across a detection region based on the interrogation signal and induce a reply signal in a receiver coil; and the receiver coil coupled to the transceiver and configured to send the reply signal to the transceiver, wherein the reply signal changes when the EAS shielding material is present in the detection region, such that the transceiver determines the presence of EAS shielding material in the detection region based on the reply signal, wherein the transmitter coil and the receiver coil are coupled and substantially concentric, wherein the transmitter coil and the receiver coil are predominantly disposed in a common plane or and predominately disposed on substantially parallel planes.

2. The metal detection system of claim 1, wherein the detection region is proximate to the metal detection system; and the transmitter coil and receiver coil are: above or in a ceiling, and wherein the substantially common plane or substantially parallel planes are substantially parallel to the ceiling; and / or below or in a ground surface, and wherein the substantially common plane or the substantially parallel planes are substantially parallel to the ground surface.

3. The metal detection of any one of claims 1-2, wherein the metal detection system further comprises a RX balance control coil coupled to the transceiver and configured to adjust the strength of the reply signal transmitted from the receiver coil to the transceiver.

4. The metal detection system of any one of claims 1-3, wherein the receiver coil is rotatable with respect to the transmitter coil while remaining substantially concentric and located on the substantially common plane or the substantially parallel planes.

5. The metal detection system of any one of claims 1-4, wherein the detection system further comprises a pedestal horizontally oriented and substantially parallel with the ground surface, wherein the transmitter coil and the receiver coil are attached to the pedestal.

6. The metal detection system of any one of claims 1-5, the metal detection system further comprising a ferrite tile disposed beneath the pedestal and configured to shield the detection system from electromagnetic interference.

7. The metal detection system of any one of claims 1-6, wherein the interrogation signal is a high frequency, AC waveform engendering the electromagnetic field to the detection region.

8. The metal detection system of any one of claims 1-7, wherein the transceiver comprises a controller configured to convert the reply signal to operating data indicating an operating status of the metal detection system.

9. The metal detection system of any one of claims 1-8, wherein the metal detection system is operatively connected to a host device, the host device being operable to adjust the reply signal transmitted from the receiver coil.

10. The metal detection system of any one of claims 1-9, wherein the metal detection system further comprises a controller operatively connected to the transceiver, the controller being configured to actuate at least one or more of an audible alarm, a light, and / or transmit a message to a host device and / or a remote device operatively connected to the controller.

11. A detection system for detecting electronic article surveillance (EAS) marker shielding material, the detection system comprising: a detection pedestal including a transmitter coil and a receiver coil, the transmitter coil and the receiver coil being substantially concentric and being disposed in a substantially common plane or on substantially parallel planes therewith, the transmitter coil being configured to generate an electromagnetic field to a detection region proximate the detection pedestal based on an interrogation signal, wherein the receiver coil is configured to generate a reply signal that changes in response to a disturbance in the electromagnetic field indicative of a presence of E AS metal shielding material in the detection region; anda controller operatively connected to the detection pedestal, the controller being configured to actuate at least one of an audible alarm and / or a visual alarm when the receiver coil generates the reply signal indicative of the presence of the EAS marker shielding material passing through the detection region.

12. The detection system of claim 11, wherein the detection pedestal further comprises a RX balance control coil configured to adjust a strength of the reply signal transmitted from the receiver coil.

13. The detection system of any one of claims 11-12, wherein the detection system further comprises a host device operatively connected to the controller, the host device being operable to adjust the strength of the reply signal transmitted from the receiver coil.

14. The detection system of claim 13, wherein the host device includes a user interface operable to adjust the strength of the interrogation signal and / or the reply signal.

15. The detection system of any one of claims 1-14, wherein the plane or planes are substantially parallel to a vertical wall.

16. A detection system for detecting electronic article surveillance (EAS) marker shielding material, the detection system comprising: a controller in communication with a transmitter coil and a receiver coil, wherein the transmitter coil and the receiver coil are coupled, substantially concentric,and predominately disposed in a substantially common plane or substantially parallel planes the controller having a processor and memory, the memory storing executable code when executed by the processor performs actions comprising receiving operating settings from a user; generating an interrogation signal in the transmitter coil, thereby causing the transmitter coil to generate an electromagnetic field to a detection region; receiving a reply signal from the receiver coil, wherein the reply signal is induced by the electromagnetic field, wherein the reply signal changes in response to a disturbance in the electromagnetic field indicative of a presence of E AS marker shielding material in the detection region; determining whether EAS marker shielding material is present in the detection region using operating data comprised of the reply signal; outputting detection system status to a user, wherein the detection system status is comprised of generating an alarm when EAS marker shield material is present in the detection region; wherein the detection region is proximate to the detection system; wherein the transmitter coil and receiver coil are: above or in a ceiling, and wherein the substantially common plane or substantially parallel planes are substantially parallel to the ceiling, and / or below or in a ground surface, and wherein the substantially common plane or substantially parallel planes are substantially parallel to the ground surface.

17. The detection system of claim 16, wherein the detection system further comprises an RX balance control coil coupled to the transceiver and configured to adjust a strength of the reply signal transmitted from the receiver coil to the transceiver.

18. The detection system of any one of claims 16-17, wherein generating an alarm is comprised of actuating at least one or more of an audible alarm, a light, and / or transmitting a message to a host device and / or a remote device operatively connected to the controller.

19. The detection system of any one of claims 16-18, wherein the receiver coil is rotatable with respect to the transmitter coil, while remaining substantially concentric and located on the substantially common plane or the substantially parallel planes.

20. The detection system of any one of claims 16-19, wherein the operating settings comprises at least one of a signal strength of the RX balance coil, a strength of the electromagnetic field, and / or a frequency of the interrogation signal; wherein the operating data is outputted to the user, the operating data comprising at least one of a signal strength of the reply signal, a noise level of the reply signal, and / or a metal detection signal.

Images