Electronic Article Surveillance System

Abstract

To provide an electronic article surveillance system (EAS) configured in a system for reducing the size of a transition zone and / or issuance of false alarms.SOLUTION: An electronic article surveillance system comprises: a controller connected to a first RFID reader and a second RFID reader; an RFID device including an associated sensor configured to record a value and to transmit the value to the controller; the first RFID reader being associated with a first read zone; and the second RFID reader being configured to detect the RFID device at a trigger threshold and associated with a second read zone. The controller modifies the trigger threshold of at least one of the first RFID reader and the second RFID reader at least partially based on the value of the sensor of the RFID device, so as to set the trigger threshold of the RFID device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to radio frequency identification ("RFID") devices. More particularly, the present invention relates to controlling the trigger threshold of RFID devices used in electronic article surveillance ("EAS") systems. [Background technology]

[0002] In retail stores, accurate counting of display and / or inventory items is important. It is also important to have an effective anti-theft system in place. RFID tags and labels (collectively referred to herein as "RFID devices") are used to perform all of these functions.

[0003] Typically, EAS systems using RFID technology have two main read zones, each containing an associated RFID reader. One read zone is an area within the store where products are presented to consumers (referred to herein as the "inventory zone"), and the other read zone is an exit area of ​​the store (referred to herein as the "sensing zone") that can sense any RFID device that is not properly deactivated to trigger some type of alarm indicating an attempt to steal the product. Typically, when a customer properly purchases an item, the cashier removes or deactivates the associated RFID device. If the RFID device is not removed or deactivated, the RFID reader reads the device and triggers an alarm or other alert in the sensing zone.

[0004] While the above-mentioned systems are widespread, they do have some drawbacks. When using RFID devices / systems for EAS systems, one common issue is whether the read range of an RFID device in a particular situation is large enough that an RFID device in the inventory zone can be read in the sensing zone, or vice versa. To reduce this risk, a transition zone is often provided between the inventory zone and the sensing zone to physically separate the two read zones. However, due to different RFID devices having higher sensitivity at the operating frequency and / or different items that affect the performance of the associated RFID devices differently, the transition zone must be relatively large. A larger transition zone means a smaller inventory zone, which means lost sales (revenue) as retailers have less physical space to present merchandise to consumers.

[0005] Although inventory zones have been maximized and transition zones have been reduced or minimized, there is still a need for an inventory control / EAS system that reduces or minimizes false alarms and is more effective at detecting theft.

[0006] Therefore, it would be advantageous to provide an EAS system configured in a manner that reduces the size of the transition zone and / or the occurrence of false alarms. Summary of the Invention

[0007] The present invention has several aspects that may be implemented individually or together in the devices, systems, and methods described and claimed below. These aspects may be employed alone or in combination with other aspects of the invention described herein, and describing these aspects together does not exclude using these aspects separately or claiming these aspects individually or in different combinations as set forth in the claims appended hereto.

[0008] In one aspect, an electronic article surveillance system includes a first read zone having an associated RFID reader and a second read zone having an associated RFID reader configured to sense an RFID device at a trigger threshold, the system further including a controller configured to set the trigger threshold based at least in part on factors selected from the group consisting of a sensor value of the RFID device, a number of times the RFID device is sensed in the first read zone, and whether the RFID device is sensed in the first read zone under predetermined conditions.

[0009] In another aspect, a method is provided for controlling an electronic article surveillance system having first and second read zones, wherein an RFID device is sensed in the second read zone at a trigger threshold, the method including setting the trigger threshold based at least in part on factors selected from the group consisting of a sensor value of the RFID device, the number of times the RFID device is sensed in the first read zone, whether the RFID device is sensed in the first read zone under predetermined conditions, and combinations thereof.

[0010] In another aspect, an electronic article surveillance system includes a first read zone including an associated RFID reader, and a portion of infrastructure is located at least partially within the first read zone. An RFID guard device is fixed relative to the portion of infrastructure. A second read zone of the system includes an associated RFID reader configured to sense an RFID inventory device associated with a portion of inventory removably associated with the portion of infrastructure at a trigger threshold. The system further includes a controller configured, upon sensing the RFID guard device by the RFID reader, to initiate a response selected from the group consisting of: modifying the trigger threshold, modifying an amount of power transmitted by the RFID reader associated with the second read zone, modifying a direction in which power is transmitted by the RFID reader associated with the second read zone, and transmitting a signal indicating that the portion of infrastructure needs to be moved away from the second read zone.

[0011] In another aspect, a method is provided for controlling an electronic article surveillance system having first and second read zones, wherein a portion of infrastructure has an associated RFID guard device located at least partially within the first read zone, and an RFID inventory device associated with a portion of inventory removably associated with the portion of infrastructure is sensed in the second read zone at a trigger threshold, the method including, upon sensing the RFID guard device in the second read zone, initiating a response selected from the group consisting of: modifying the trigger threshold, modifying an amount of power transmitted by an RFID reader associated with the second read zone, modifying a direction in which power is transmitted by the RFID reader associated with the second read zone, and transmitting a signal indicating that the portion of infrastructure needs to be moved away from the second read zone. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an exemplary diagram of an exemplary embodiment of an electronic article surveillance system according to aspects of the present disclosure. [Figure 2] 1 is an exemplary diagram of another exemplary embodiment of an electronic article surveillance system according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Where necessary, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Accordingly, the specific details disclosed herein should not be construed as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously use the present invention in substantially any suitable manner.

[0014] FIG. 1 illustrates an EAS system 10 using RFID technology according to one embodiment of the present disclosure. The EAS system 10 of FIG. 1 includes an inventory zone 12 and a sensing zone 14, with a transition zone 16 separating the two read zones 12 and 14. The EAS system 10 further includes a controller 18 coupled to a first RFID reader 20 associated with the inventory zone 12 and a second RFID reader 22 associated with the sensing zone 14. Multiple inventory portions 24, 26 are shown located within the inventory zone 12, each having an associated RFID device 28, 30 (referred to herein as an RFID inventory device). As described in more detail herein, the inventory portions 24, 26 may be configured differently, which may affect the performance of the associated RFID devices 28, 30 differently.

[0015] As noted above, inventory zone 12 refers to the area within the store where products are presented to consumers, while sensing zone 14 refers to the store's exit area where any RFID inventory device that is not properly deactivated may be detected to trigger some type of alarm indicating an attempted theft. If a customer properly purchases an item, the cashier will have the associated RFID inventory device removed or deactivated. If an RFID inventory device is not removed or deactivated, it will be detected in sensing zone 14 and trigger an alarm or other alert to notify store personnel.

[0016] Each inventory portion 24, 26 is shown in FIG. 1 as removably associated with an infrastructure portion 32, 34 configured to support and display the associated inventory portion in the inventory zone 12. In the illustrated embodiment, one of the infrastructure portions 32 is configured as a mannequin, while the other of the infrastructure portions 34 is configured as a table, although it should be understood that the infrastructure portions may be configured differently without departing from the scope of this disclosure. In the embodiment of FIG. 1, each infrastructure portion 32, 34 includes an associated RFID device 36, 38 (referred to herein as an RFID guard device) that is fixed relative to the infrastructure portion 32, 34 (e.g., by being attached to the infrastructure portion 32, 34). Unlike the RFID inventory devices 28, 30, the RFID guard devices 36, 38 are not configured to generate an alarm when detected in the detection zone 14, although, as will be described in more detail, the RFID guard devices 36, 38 may be used to reduce false alarms caused by detection of the RFID inventory device in the detection zone 14.

[0017] The EAS system 10 of FIG. 1 is shown to include an additional read zone 40 configured to receive a portion of inventory prior to its transfer to the inventory zone 12. This initial or preliminary read zone 40 is provided to determine the number of units of the portion of inventory in storage before the portion of inventory is transferred to the inventory zone 12 for display and customer review. The initial or preliminary read zone 40 may be configured in various ways without departing from the scope of this disclosure. In the illustrated embodiment, the initial or preliminary read zone 40 is configured as an RFID read chamber configured to receive multiple portions of inventory and their associated RFID devices, including associated RFID readers 42. The RFID read chamber may be relatively large (e.g., configured to receive multiple containers loaded on a pallet) or smaller (e.g., configured to receive a single container), depending on the needs and configuration of the store. In other embodiments, the initial or backup read zone 40 (if provided) may be configured differently, such as an RFID-enabled gate through which inventory passes before reaching the inventory zone 12, or a warehouse or storage area where RFID inventory devices are read or sensed, for example, by a handheld RFID reader operated by a store employee.

[0018] It should be understood that the configuration shown in FIG. 1 is merely exemplary, and that an EAS system according to the present disclosure may be configured differently without departing from the scope of the present disclosure. For example, while FIG. 1 shows separate RFID readers 20, 22 associated with inventory zone 12 and sensing zone 14, it is within the scope of the present disclosure to have a single RFID reader 46 associated with both zones 12 and 14, such as EAS system 10' shown in FIG. 2. In some embodiments, an inventory zone and / or sensing zone has multiple readers, e.g., two, three, four, five, or more. In some embodiments, the multiple readers are controlled by a single controller. In other embodiments, each reader is controlled by its own controller. In still other embodiments, the multiple readers are controlled by two or more controllers, but the number of controllers is less than the number of readers, so that at least two or more readers are controlled by a single controller.

[0019] Regardless of the particular configuration of the EAS system, transition zone 16 is ideally sized and configured so that RFID devices (particularly RFID inventory devices) located in inventory zone 12 are sensed only by RFID reader 20 associated with inventory zone 12 (or, in the case of system 10' of FIG. 2, only by signals emitted by RFID reader 18 into inventory zone 12, and not into sensing zone 14), and not by RFID reader 22 associated with sensing zone 14. Vice versa, it is advantageous for RFID devices located in sensing zone 14 to be sensed only by sensing zone 14, and not by inventory zone 12. While this can be achieved by providing a wide transition zone 16, such an approach is an unsatisfactory solution because it reduces the size of inventory zone 12.

[0020] According to one aspect of the present disclosure, the size of transition zone 16 may be reduced by instead adjusting the level at which RFID inventory devices are sensed in sensing zone 14 (herein referred to as the "trigger threshold"). While this aspect of the present disclosure describes adjusting the trigger threshold of sensing zone 14 (to prevent false alarms when RFID inventory devices in inventory zone 12 are sensed in sensing zone 14), it should be understood that the trigger threshold of inventory zone 12 may similarly be adjusted to prevent a situation in which an RFID device in sensing zone 14 is sensed in inventory zone 12.

[0021] Because there are several factors that can affect the performance characteristics of an RFID device (and thereby whether such an RFID device is sensed in a separate read zone), there are a variety of conditions that may warrant a change in the trigger threshold for a particular RFID device. According to one approach, an RFID inventory device may include a sensor that records a particular value that may be transmitted to a controller 18 of the EAS system 10, 10′. Depending on the sensor value, the controller 18 determines whether to adjust the trigger threshold of the RFID inventory device with which the sensor is associated, which may include decreasing the trigger threshold (e.g., if the value indicates that a portion of the inventory associated with the RFID inventory device is at risk of theft) or increasing the trigger threshold (e.g., if the value indicates that a portion of the inventory associated with the RFID inventory device is not at risk of theft). Various RFID inventory devices may each be uniquely programmed such that the controller 18 assigns the appropriate trigger threshold to the appropriate RFID inventory device.

[0022] The sensor may be variously configured without departing from the scope of the present disclosure. In one exemplary embodiment, the sensor value is capacitance. Such a sensor may be particularly useful in an auto-tunable RFID device configured to change capacitance to optimize the performance of the RFID device. For example, when an auto-tunable RFID device is associated with a low-loss material (e.g., a T-shirt or other lightweight clothing), the RFID device may tend to auto-tune to a relatively high capacitance to reduce the performance peak to the desired RFID reader operating band. In contrast, when an auto-tunable RFID device is associated with or placed near a high-loss material (e.g., an item with a high moisture content, such as a human body), the RFID device may tend to auto-tune to a relatively low capacitance to increase the performance peak. A relatively high capacitance may require adjustment of the trigger threshold in one direction, while a relatively low capacitance may require adjustment of the trigger threshold in the opposite direction. There may also be cases where the sensed capacitance is at a level that does not require adjustment of the trigger threshold.

[0023] In another exemplary embodiment, the sensor may be configured as a dielectric sensor. In this case, the sensor value is the permittivity of the dielectric. Such a sensor may be advantageous when the RFID device is not self-adjusting but instead has performance that is affected only by external factors (e.g., the characteristics of a portion of the associated inventory). Dielectric loading may be determined, in one example, by measuring a value associated with the RFID device, such as received signal strength, as the RFID reader changes frequency. When an RFID device is associated with a light dielectric, read performance tends to increase with increasing read frequency, whereas when an RFID device is associated with a heavy dielectric, read performance tends to decrease with increasing read frequency. If the sensor value indicates an association of the RFID device with a light dielectric, the trigger threshold may be increased to prevent false alarms (without increasing the risk of the RFID device not being properly sensed). Conversely, if the sensor value indicates an association of the RFID device with a heavy dielectric, the performance of the RFID device may be degraded, in which case the trigger threshold may be decreased to properly sense the RFID device without increasing the risk of false alarms. It may also be the case that the permittivity of the sensed dielectric is at a level that does not require adjustment of the trigger threshold.

[0024] In another exemplary embodiment, the sensed value may be temperature. Typically, a piece of merchandise is near a person when being stolen, tending to increase the sensed temperature. Thus, an increase in the temperature of an RFID inventory device may indicate an increased risk of an attempted theft of the associated merchandise, in which case the controller 18 may act to decrease the trigger threshold to better ensure that the RFID inventory device will be properly sensed if it moves into the sensing zone 14 without being disarmed.

[0025] In another exemplary embodiment, the sensed value is the degree of movement. Stolen products may move toward the store exit (and toward sensing zone 14), whereas items displayed in inventory zone 12 are likely stationary. Thus, an increased degree of movement experienced by an RFID inventory device indicates an increased risk of attempted theft of associated merchandise; in this case, controller 18 may act to decrease the trigger threshold to better ensure that the RFID inventory device is properly sensed if it moves into sensing zone 14 without disengaging. An exemplary motion detector may be a moving object, such as a beam or flap, that changes a value, such as the voltage, at the RFID chip port of the RFID device, or a similar device that modulates the input impedance of the RFID chip, thereby modulating its response. Materials such as piezoelectric plastics, resistive materials that change when stretched or compressed, or parallel plate capacitor configurations, where the plate separation is affected by movement, may also be used.

[0026] However, while it is generally appropriate to decrease the trigger threshold upon detecting movement, this is not always the case. For example, a particular RFID device may be associated with a portion of inventory intended to be used to replenish merchandise inventory in inventory zone 12 during the time EAS system 10, 10′ is operational. This may be the case for an RFID inventory device that was most recently detected or read in initial or backup read zone 40, but because such RFID inventory device has not yet been moved to inventory zone 12 so that associated merchandise may be displayed and viewed by customers. Because movement of such an RFID inventory device does not indicate the potential theft of the associated merchandise, but instead indicates the movement of merchandise into inventory zone 12, the trigger threshold for such an RFID inventory device may be set to a maximum (or at least elevated) level for a specified period of time (e.g., 15 to 60 minutes). After that period has elapsed, controller 18 may process the RFID inventory device as described above, which may include subsequent movement of the RFID inventory device causing controller 18 to decrease the trigger threshold to better prevent theft of merchandise associated with the RFID inventory device.

[0027] According to another aspect of the present disclosure, trigger thresholds may be adjusted based on the performance of RFID inventory devices in the initial or preliminary read zone 40. For example, if the initial or preliminary read zone 40 is configured as an RFID read chamber (because the RFID read chamber includes multiple antennas configured to emit signals into the RFID read chamber), each RFID device may be read or sensed a certain number of times, which may vary depending on a number of factors, including certain characteristics of the associated inventory. The number of times an RFID inventory device is read may be encoded on the RFID device or stored in a database accessible by the controller 18 of the EAS system 10, 10′. The controller 18 may adjust the trigger threshold for a particular RFID inventory device based on the number of times it is read in the RFID read chamber. A low number of reads may indicate that the RFID device is associated with a difficult-to-read product (e.g., goods with a high moisture content), while a high number of reads may indicate that the RFID device is associated with an easy-to-read product (e.g., lightweight clothing). For RFID inventory devices with low read counts, the trigger threshold may be decreased to better ensure that the RFID inventory device is properly read (without increasing the risk of false alarms). For RFID inventory devices with high read counts, the trigger threshold may be increased to reduce the risk of false alarms without increasing the risk that the RFID inventory device will not be properly read or sensed.

[0028] According to another aspect of the present disclosure, the trigger threshold may be adjusted when the controller 18 determines that an RFID inventory device has been sensed by an RFID reader associated with a read zone, where the RFID inventory device is located under predetermined conditions. For example, an RFID inventory device may be read or sensed in the inventory zone 12 when there are no people (or at least no customers) in the inventory zone 12 (e.g., as determined by a camera or other means associated with the controller 18) or when there are no RFID inventory devices moving between the inventory zone 12 and the sensing zone 14. An RFID inventory device sensed in the inventory zone 12 under such conditions may be deemed to be associated with merchandise with a lower risk of theft (compared to an RFID inventory device sensed in the inventory zone 12 while a customer is present). The trigger threshold for such an RFID inventory device may be increased by the controller 18 to better ensure that such an RFID inventory device does not cause a false alarm. Because the risk of theft increases when a customer enters the inventory zone 12, the trigger threshold for an RFID inventory device in the inventory zone 12 may be decreased by the controller 18.

[0029] In some embodiments, a combination of capacitance, dielectric constant, temperature, and degree of motion may be used to adjust the trigger threshold.

[0030] While the above discussion is limited to RFID inventory devices, it should be understood that a response or alteration to the operation of the EAS system may be initiated when an RFID guard device is detected in the detection zone 14. As noted above, the RFID guard devices 36, 38 are intended to remain located within the inventory zone 12 associated with a portion of infrastructure 32, 34 used to display and / or support one or more portions of inventory 24, 26. Thus, detection of an RFID guard device in the detection zone 14 may indicate an attempt to steal the associated portion of infrastructure (possibly along with any portion of inventory associated with that portion of infrastructure) or may indicate a portion of infrastructure located too close to the detection zone 14, which may result in a false alarm caused by the RFID inventory device associated with the portion of inventory associated with the portion of infrastructure corresponding to the RFID guard device.

[0031] Regardless of the circumstances under which an RFID guard device is detected in the sensing zone 14, any of a number of responses can be initiated by the system controller 18 to prevent or reduce the likelihood of a false alarm. For example, one possible response is for the controller 18 to modify the trigger threshold of one or more RFID inventory devices associated with the portion of inventory associated with the portion of infrastructure corresponding to the RFID guard device (e.g., adjusting the trigger threshold of an RFID device affixed to a shirt worn by a mannequin in the inventory zone 12), which may include increasing the trigger threshold to reduce false alarms. Another possible response is to modify the amount of power transmitted by an RFID reader associated with the sensing zone 14 and / or (if the RFID reader's antenna is active) change the direction in which power is transmitted by the RFID reader to avoid detection by the RFID guard device. Yet another possible response is for the controller 18 to send a signal indicating that a store employee should move the portion of infrastructure associated with the RFID guard device (or merchandise associated with the portion of infrastructure) away from the sensing zone 14. In an exemplary embodiment, the signal may be provided by a light or other indicator associated with a portion of the infrastructure, or by a company network, indicating that a portion of the infrastructure or associated merchandise needs to be moved to reduce the risk of false alarms.

[0032] RFID guard devices may be offered in various sensitivity ratings, for example, "A" is highly sensitive, meaning that there is a relatively low risk of over-reading if such an RFID guard device is sensed in the sensing zone 14. "B" types are relatively less sensitive, meaning that there is a significant possibility of over-reading if sensed in the sensing zone 14, in which case a different response may be initiated by the controller 18 compared to the response that may be initiated if an "A" type RFID guard device is sensed. To prevent problems, trigger thresholds for components of the EAS system 10, 10' configured to sense RFID guard devices may be increased.

[0033] In an alternative form, an RFID guard device may have more than one identification associated with it. An RFID device most basically includes an RFID chip coupled to an antenna. To provide an RFID guard device with multiple identifications, multiple different RFID chips may be coupled to a common antenna, each with a different sensitivity (e.g., one "A" type RFID chip with high sensitivity, one "B" type RFID chip with low sensitivity, and one "C" type RFID chip with even lower sensitivity). By determining which chips are sensed in sensing zone 14, system controller 18 can determine the risk of a false alarm and take various actions based on the sensitivity of the sensed chips.

[0034] It will be understood that the above-described embodiments are illustrative of some of the applications of the principles of the present invention. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the invention as claimed, including combinations of features individually disclosed or claimed herein. For this reason, the scope of the present invention is not limited to the above description, but is as set forth in the following claims, which claims are understood to be directed to features of the present invention, including combinations of features individually disclosed or claimed herein.

[0035] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 62 / 970,933, filed February 6, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. a controller connected to the first RFID reader and the second RFID reader; an RFID device including an associated sensor configured to record a value and transmit said value to said controller; the first RFID reader associated with a first read zone; a second RFID reader associated with a second read zone configured to sense the RFID device at a trigger threshold; Including, the controller is configured to set the trigger threshold of the RFID device by adjusting the trigger threshold of at least one of the first RFID reader and the second RFID reader based at least in part on the value of the sensor of the RFID device; the value of the sensor includes temperature; Electronic Article Surveillance System.

2. the value of the sensor includes a degree of movement; The electronic article surveillance system of claim 1 , wherein the controller is configured to decrease the trigger threshold when the RFID device moves.

3. the first read zone includes an inventory zone; the second read zone includes a sensing zone separated from the inventory zone by a transition zone; 10. The electronic article surveillance system of claim 1.

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