HK1233030B - Handheld deactivator with integrated thermal sensor - Google Patents

Description

Handheld deactivator with integrated thermal sensor

Technical Field

This document relates generally to electronic article surveillance ("EAS") systems. More particularly, this document relates to a handheld deactivator for an EAS system with an integrated thermal sensor.

Background Art

EAS systems are well known for preventing or deterring the unauthorized removal of items from a controlled area. In a typical EAS system, a security tag is attached to the item to be protected. The security tag is designed to interact with an electromagnetic field located at the exit of the controlled area. If a security tag is brought into the electromagnetic field or "interrogation zone", the presence of the security tag can be detected and appropriate action can be taken. For controlled areas (such as retail areas), the appropriate action taken when a security tag is detected may be to generate an alarm. Some types of security tags remain attached to the item to be protected, but before the item is removed from the controlled area with permission, the security tag is deactivated by a deactivation device that changes the characteristics of the security tag so that the security tag will no longer be detectable within the interrogation zone.

In some cases, the deactivation device comprises a handheld deactivation device used by store personnel. The handheld deactivation device may be part of a handheld barcode scanner or other battery-powered device. In such cases, the handheld deactivation device may be pointed at a person (e.g., a member of the public) approaching it. In this manner, the person may be exposed to electric and magnetic fields emitted from the handheld deactivation device at a given frequency (e.g., 3.4 kHz). Due to the risk of harmful exposure of the public to electric and magnetic fields, which may result in a deterioration of the public's health, various health protection agencies restrict the use of such handheld deactivation devices.

Summary of the Invention

The present invention relates to a system and method for controlling the operation of a handheld scanning and deactivation ("HSD") device. The method involves determining whether a person is within a defined distance range of the HSD device. If it is determined that a person is within the defined distance range of the HSD device, the HSD device is prevented from performing a first operation. Conversely, if it is determined that no person is within the defined distance range of the HSD device, the first operation is initiated. The lower limit of the defined distance range can be 0 centimeters, and the value of the upper limit of the defined distance range can represent a distance from the HSD device at which the intensity of the magnetic field is considered safe for human exposure.

In some cases, the first operation includes an interrogation operation to detect the presence of an electronic article surveillance security tag or a deactivation operation to deactivate the electronic article surveillance security tag. If the first operation includes an interrogation operation, determining whether a person is near the HSD device can be performed in response to or after detecting a barcode on an object being scanned by the HSD device. Alternatively, if a person is determined to be within a defined distance range of the HSD device, the HSD device can be prevented from performing the second operation. In this case, the second operation includes a deactivation operation to deactivate the electronic article surveillance security tag.

In the above or other cases, the method further involves determining whether a person located within a defined distance range of the HSD device is other than an operator of the HSD device. When the person is determined to be other than the operator, the HSD device is prevented from performing the first operation. Conversely, when the person is determined to be the operator, the first operation is initiated.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be described with reference to the following drawings, wherein like reference numerals represent like items throughout, and in which:

FIG. 1 is a schematic diagram of an exemplary architecture of an HSD device useful for understanding the present invention.

FIG. 2 is a block diagram of an exemplary architecture of electronic circuitry of the HSD shown in FIG. 1 .

FIG3 is a schematic diagram of an exemplary architecture of a sending module of the HSD shown in FIG1 .

FIG. 4 is a schematic diagram illustrating an exemplary architecture of a receiving module of the HSD shown in FIG. 1 .

FIG5 is a schematic diagram illustrating an exemplary architecture of a deactivation module of the HSD shown in FIG1 .

6A-6B collectively provide a flow chart of an exemplary method of controlling the operation of the deactivation module shown in FIG. 5 .

FIG. 7 is a schematic diagram useful for understanding the magnetic field pattern of the HSD shown in FIG. 1 .

DETAILED DESCRIPTION

It will be readily understood that the components of the embodiments generally described herein and illustrated in the accompanying drawings may be arranged and designed in a variety of different configurations. Thus, the following more detailed description of various embodiments, as illustrated in the accompanying drawings, is not intended to limit the scope of the present disclosure but is merely representative of various embodiments. Although various aspects of the embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

The present invention may be implemented in other specific forms without departing from its spirit or essential characteristics. The described embodiments should be considered in all respects as illustrative only and not restrictive. Therefore, the scope of the present invention is indicated by the appended claims rather than by this detailed description. All changes that come within the meaning and range of equivalents of the claims are intended to be included within the scope of the claims.

References to features, advantages, or similar language in this specification do not imply that all features and advantages that may be realized by the present invention are or are included in any single embodiment of the present invention. Rather, language referring to features and advantages should be understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, throughout this specification, discussions of features and advantages and similar language may, but do not necessarily, refer to the same embodiment.

Furthermore, the features, advantages, and characteristics described herein may be combined in any suitable manner in one or more embodiments. Based on the description herein, one skilled in the relevant art will appreciate that the present invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other cases, additional features and advantages that may not be present in all embodiments of the present invention may be implemented in certain embodiments.

Reference throughout this specification to "one embodiment," "an embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment of the present invention. Thus, throughout this specification, the phrases "in one embodiment," "in an embodiment," and similar language may, but do not necessarily, all refer to the same embodiment.

As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. As used herein, the term "including" means "including, but not limited to."

Referring now to FIG. 1 , a schematic diagram of an exemplary HSD device 100 is provided that is useful for understanding the present invention. The HSD device 100 is configured for use in an EAS system as a cordless device for deactivating EAS security tags. The HSD device 100 will be described below with respect to a magnetic EAS system that requires generating a magnetic field for deactivating EAS security tags. The present invention is not limited thereto. The present invention can be applied to a variety of different EAS systems and EAS security tags.

Notably, the HSD device 100 implements its electrical characteristics in a hardware package that has a relatively low overall weight to minimize operator fatigue and a relatively low overall energy requirement to make battery operation feasible. A deactivation range of at least about 3 inches, a weight of less than about 2 pounds, and a battery life of at least about 12 hours at a deactivation rate of 200 per hour are desirable.

1 , the HSD device 100 may include an air core coil 104, electronic circuitry 102, a housing 106, and a battery 108. The coil size and ampere-turns of the air core coil 104 are selected to minimize weight and battery energy while achieving a magnetic field level required to deactivate magnetic EAS security tags at least about 3 inches from the handheld scanning and deactivation device 100. The battery 108 may be fully contained within the housing 106 or inserted into a mating connector and attached to the housing 106 in a flush manner.

An exemplary architecture of the electronic circuit 102 will be described below with respect to Figures 2-5. However, it will be understood that the electronic circuit 102 is configured to eliminate or at least significantly minimize the risk of exposing a person to electric and magnetic fields emitted from the handheld deactivation device at sub-optical frequencies. Thus, the present disclosure provides an improved HSD device that implements new techniques for initiating a deactivation operation (discussed in detail below) compared to techniques implemented by conventional HSD devices. In fact, the HSD device of the present invention complies with the respective device regulations of various health agencies (e.g., the European Regulatory Agency). In contrast, conventional HSD devices do not comply with such device regulations and are therefore limited in the overall geographical location in which they can be used.

Referring now to FIG. 2 , a block diagram of an exemplary architecture of the electronic circuitry 102 of the HSD device 100 shown in FIG. 1 is provided. It is noteworthy that the HSD device 100 is configured to operate in several operating modes. These operating modes include, but are not limited to, a manual operating mode, an automatic operating mode, a hands-free operating mode, a detection-only mode, and/or a deactivation-only mode. The operating mode of the HSD device 100 can be modified by its user via an interface module 206 of the electronic circuitry 102. The interface module 206 includes, but is not limited to, a display screen, switches, and/or a keyboard that facilitate user-software interaction.

In one or more of these operating modes, the electronic circuit 102 performs operations to detect a barcode set on an object. If a barcode is detected, the electronic circuit 102 (more specifically, the sensor 250 and the microprocessor 208) optionally performs a thermal sensing operation to detect whether a person (e.g., a member of the public other than the operator) is within a specified distance (e.g., 1-2 feet) from the HSD device 100. In some cases, the sensor field of view matches the deactivation field so that a person can be within the range of the electric/magnetic field during the deactivation pulse field. In addition, the electronic circuit 102 can distinguish between the operator of the HSD device 100 and other people who are close to the HSD device. If someone is indeed within a specified distance of the HSD device 100, further operation of the HSD device is blocked until the person moves to a safe distance (e.g., 10 feet) from the HSD device or is no longer close to the HSD device.

If no person is within the specified distance of the HSD device 100, an interrogation operation of the HSD device is initiated. The interrogation operation involves transmitting an interrogation signal in the direction of the EAS security tag. For example, the interrogation signal may include a 1.6 millisecond (ms) burst at a desired interrogation frequency (e.g., 58 kHz) transmitted at a repetition rate of approximately 40 Hz via the transmission module 216 and the air-core coil 104. The timing of the burst is controlled by a programmable array logic (PAL) unit 214. The PAL unit 214 may include, but is not limited to, a PAL part number PALLV16V8z, available from Lattice Semiconductor of Portland, Oregon. Typically, the burst will last for a default period of time (e.g., approximately 3-4 minutes) or a selected period of time, depending on the operating mode.

Upon receiving the interrogation signal, the EAS security tag resonates to transmit a return signal. The return signal is then received by the receiving module 218 of the electronic circuit 102 and forwarded to the digital signal processor (DSP) 210 via the analog-to-digital (A-D) converter 212.

The DSP 210 of the electronic circuit 102 processes the return signal to determine whether it is a valid EAS security tag signal. In this regard, the DSP 210 analyzes the return signal to detect selected properties thereof. For example, the return signal must have appropriate spectral content and must be received within a continuous window as expected. If the DSP 210 determines that the return signal is a valid EAS security tag signal, the DSP 210 signals the microprocessor 208 to initiate an optional thermal sensing operation, initiate a deactivation operation, or initiate a detection indicator operation, depending on the specific operating mode. The indication of EAS security tag detection may take the form of an audio, visual, and/or tactile alert to the user of the HSD device 100.

In some cases, microprocessor 208 includes, but is not limited to, a microprocessor with part number 68HC908GP32, which is available from Motorola, Inc. The present invention is not limited thereto. Any known or future known microprocessor may be used in the present invention without limitation.

Thermal sensing operations are typically performed by the sensor 250 and the microprocessor 208 to detect whether a person (e.g., a member of the public) is within a specified distance (e.g., 1-2 feet) of the HSD device 100. If a person is indeed within the specified distance of the HSD device 100, further operation of the HSD device is prevented until the person moves to a safe distance (e.g., 10 feet) from the HSD device or is no longer in proximity to the HSD device.

If no person is within the specified distance of the HSD device 100, a deactivation operation of the HSD device is initiated to deactivate the EAS security tag. To deactivate the EAS security tag, the microprocessor 208 signals the deactivation module 220 to generate a deactivation pulse for deactivating the EAS security tag. In some cases, the deactivation module 220 uses a boost inverter 222 to convert the DC battery voltage of the battery 108 into a high-current alternating pulse with a decaying envelope. The high-current alternating pulse deactivates the EAS security tag.

In some cases, the battery 108 is a rechargeable battery. Thus, a battery charging station (BCS) communication unit 204 is provided to facilitate recharging of the battery. The BCS communication unit 204 can transmit battery charge information and battery charge status information to the microprocessor 208. This information can be output to a user of the HSD device 100 via the interface module 206.

3 , a schematic diagram of an exemplary architecture of the transmit module 216 of the HSD device 100 is provided. The transmit module 216 includes a transmit driver amplifier 306, passive components 302, 304, and a switch 308. The switch 308 is coupled to the microprocessor 208. The microprocessor 208 controls the opening and closing of the switch 308 to turn the transmit module 216 on and off. In this regard, the microprocessor 208 can transmit a pulse signal to the switch 308 via a delay 310. The pulse signal causes the switch to toggle between an open position and a closed position.

Microprocessor 208 also controls PAL unit 214 to generate an interrogation signal at an appropriate transmit frequency and burst rate. The interrogation signal is then transmitted from PAL unit 214 to transmit driver amplifier 306. Transmit driver amplifier 306 sets the transmit current (or power) of the interrogation signal based on information received from microprocessor 208. This information can be specified via the voltage level of a control signal generated by microprocessor 208. The voltage level of the control signal is dynamically adjusted based on the level of detected ambient noise. The interrogation signal is then transmitted from transmit driver amplifier 306 to air-core coil 104 via resistor 304 and capacitor 302. The interrogation signal is then transmitted through air-core coil 104 at the specified power level.

Referring now to FIG. 4 , a schematic diagram illustrating an exemplary architecture of the receiving module 218 of the handheld scanning and deactivation device 100 is provided. As described above, the receiving module 218 is configured to receive a return signal from an EAS security tag. The return signal from the air-core coil 104 passes through capacitor 402, amplifier stages 408 and 410, and low-pass filter stages 412 and 414. The return signal is then converted from analog to digital by the A-D converter 212. The digital return signal is then sent to the DSP 210 for verification processing as described above. After verifying that the digital return signal possesses the attributes of a valid return signal, the DSP 210 signals to the microprocessor 208 that a functional EAS security tag has been detected.

Referring now to FIG. 5 , a schematic diagram of an exemplary architecture of the deactivation module 220 of the handheld scanning and deactivation device 100 is provided. The deactivation module 220 includes a pulse width modulator (PWM) 504. The PWM 504, in combination with a capacitor 512 and an inductor 508, forms a boost inverter 222. As described above, the boost inverter 222 converts the nominal DC battery voltage from a relatively low voltage level (e.g., 8 volts) to a relatively high voltage level (e.g., 125 volts). When the switch 514 is closed in response to a command from the microprocessor 208, the fully charged capacitor 512 is connected to the air-core coil 104. This initiates a natural resonant discharge, which generates a decaying AC sinusoidal current waveform in the air-core coil 104.

In some cases, the deactivation frequency is approximately 800 Hz with a 25% decay rate. The inductance, capacitance, and initial voltage of the capacitor determine the strength of the current waveform. These parameters are adjusted to produce a magnetic field level of sufficient strength to deactivate EAS security tags within a desired range of up to approximately 3 inches. The embodiments of the present invention are not limited to the specific details of these scenarios.

With reference now to Figure 6A-6B, the flow chart of the exemplary method 600 of the operation that is used to control HSD equipment (for example, the HSD equipment 100 of Fig. 1) is provided.Method 600 starts from step 602 and proceeds to step 604.In step 604, the HSD equipment detects the bar code that is arranged on the object.After this, in step 606, the HSD equipment can optionally perform heat sensing operation, to detect whether there is someone (except the operator of HSD) positioned at the distance range (for example, 0-10 feet) of the restriction of HSD equipment.It should be noted that the HSD equipment can distinguish the operator with other people near it.In this regard, the HSD equipment can detect the people that are positioned at its front, left and/or right side.Because the operator will be most likely positioned at the rear of HSD equipment, and as shown in Figure 7, electric field/magnetic field extends relatively not far behind the rear of HSD equipment, thereby the thermal sensor (for example, the thermal sensor 250 of Fig. 2) of HSD equipment does not necessarily need to detect the people that are positioned at the rear of HSD equipment. Thus, in some cases, the thermal sensor 250 is tuned to detect only the presence and/or movement of a person within a defined distance range in front of, to the left of, and/or to the right of the HSD device. Additionally or alternatively, the microprocessor of the HSD device (e.g., microprocessor 208 of FIG. 1 ) is configured to determine which detected presence/movement of a person is located in front of, to the left of, and/or to the right of the HSD device. In this case, the microprocessor may ignore thermal sensor information regarding the presence/movement of a person detected within other defined distance ranges (e.g., 1-2 feet) behind the HSD device.

If a person is detected within the defined distance range from the HSD device [608: Yes], the method 600 returns to step 606 so that additional thermal sensing operations can be performed. Conversely, if no person is detected within the defined distance range from the HSD device [608: No], the method 600 proceeds to step 610. In some cases, the lower limit of the defined distance range is 0 centimeters, and the value of the upper limit of the defined distance range represents the distance from the HSD device at which the strength of the magnetic field is considered safe for human exposure. Step 610 involves initiating an interrogation operation of the HSD device. In practice, as shown in step 612, the HSD device transmits an interrogation signal in the direction of the EAS security tag. In turn, as shown in step 614, the EAS security tag transmits a return signal. In the next step 616, the HSD device receives the return signal.

As shown in step 618, the return signal is processed at the HSD device to determine whether it is a valid EAS security tag signal. If the return signal is not a valid EAS security tag signal [620: No], step 622 is executed and method 600 ends or performs other processing. Alternatively, if the return signal is a valid EAS security tag signal [620: Yes], method 600 continues with steps 624, 626, or 628 of Figure 6B, depending on the mode of the HSD device. Step 624 involves the HSD device optionally initiating and performing a deactivation operation to deactivate the EAS security tag. Step 624 may be performed if the thermal sensing operation of the previous steps 606-608 was performed. Step 626 involves the HSD device optionally initiating and performing a detection indication operation.

Step 628 involves optionally performing a thermal sensing operation to detect whether a person (other than the operator of the HSD device) is within a defined distance from the HSD device. Step 628 may be performed if the thermal sensing operations of steps 606-608 have been performed or not. Step 628 is similar to step 606. Thus, the discussion of step 606 is sufficient for understanding step 628.

If a person is indeed within the defined distance range of the HSD device [630: Yes], method 600 returns to step 628. Conversely, if a person is not within the defined distance range of the HSD device [630: No], the method proceeds to step 632. In step 632, a deactivation operation of the HSD device is initiated to deactivate the EAS security tag. Therefore, as shown in step 634, the HSD device generates a deactivation pulse for deactivating the EAS security tag. Subsequently, step 636 is executed, and method 600 ends.

All devices, methods and algorithms disclosed and claimed herein can be manufactured and executed according to the present disclosure without the need for additional experimentation. Although the present invention has been described in terms of preferred embodiments, it will be understood by those skilled in the art that the order of steps of the devices, methods and methods can be changed without departing from the concept, spirit and scope of the present invention. More specifically, it will be understood that certain components can be added to, combined with or replaced the components described herein, and the same or similar results will be achieved. All such similar substitutions and modifications understood by those skilled in the art should be considered to be within the spirit, scope and concept of the present invention as defined.

The features and functions disclosed above and alternatives can be combined into many other different systems or applications. Those skilled in the art may make various currently unforeseen or unanticipated substitutions, modifications, changes or improvements, which should also be encompassed by the disclosed embodiments.

Claims (18)

1. A method for controlling the operation of a handheld scanning and deactivation HSD device, the method comprising: determining whether a person is within a defined distance range of the HSD device; If it is determined that the person is within the defined distance range of the HSD device, preventing the HSD device from performing a first operation that results in generating a magnetic field; and If it is determined that the person is not within the defined distance range of the HSD device, the first operation is initiated. 2. The method of claim 1, wherein the first operation comprises an interrogation operation to detect the presence of an electronic article surveillance security tag. 3. The method of claim 1, wherein the first operation comprises a deactivation operation to deactivate an electronic article surveillance security tag. 4. The method of claim 2, further comprising preventing the HSD device from performing a second operation if it is determined that the person is within the limited distance range of the HSD device, the second operation comprising a deactivation operation that deactivates an electronic article surveillance security tag. 5. The method of claim 1 , wherein a lower limit of the defined distance range is 0 centimeters, and a value of an upper limit of the defined distance range represents a distance from the HSD device at which the intensity of the magnetic field is considered safe for human exposure. 6. The method of claim 1, wherein the step of determining whether a person is within a defined distance range of the HSD device is performed in response to detecting a bar code on an object being scanned by the HSD device. 7. The method of claim 1, further comprising determining whether the person within the defined distance range of the HSD device is a person other than an operator of the HSD device. 8. The method according to claim 7, wherein when it is determined that the person located within the limited distance range of the HSD device is a person other than the operator, the step of preventing the HSD device from performing the first operation is performed. 9. The method according to claim 7, wherein the step of initiating the first operation is performed when it is determined that the person located within the limited distance range of the HSD device is the operator. 10. A handheld scanning and deactivation HSD device comprising: electronic circuit, configured to determining whether a person is within a defined distance range of the HSD device, If it is determined that the person is within the defined distance range of the HSD device, preventing the HSD device from performing a first operation that results in generating a magnetic field, and If it is determined that the person is not within the defined distance range of the HSD device, the first operation is initiated. 11. The HSD device of claim 10, wherein the first operation comprises an interrogation operation to detect the presence of an electronic article surveillance security tag. 12. The HSD device of claim 10, wherein the first operation comprises a deactivation operation to deactivate an electronic article surveillance security tag. 13. The HSD device of claim 11 , wherein the electronic circuit is further configured to prevent the HSD device from performing a second operation if it is determined that the person is within the limited distance range of the HSD device, the second operation comprising a deactivation operation of deactivating an electronic article surveillance security tag. 14. The HSD device of claim 10, wherein a lower limit of the defined distance range is 0 centimeters, and a value of an upper limit of the defined distance range represents a distance from the HSD device at which the intensity of the magnetic field is considered safe for human exposure. 15. The HSD device of claim 10, wherein the step of determining whether a person is within a defined distance range of the HSD device is performed in response to detection of a bar code on an object being scanned by the HSD device. 16. The HSD device of claim 10, wherein the electronic circuit is further configured to determine whether the person within the defined distance range of the HSD device is a person other than an operator of the HSD device. 17. The HSD device according to claim 16, wherein when it is determined that the person located within the limited distance range of the HSD device is a person other than the operator, the step of preventing the HSD device from performing the first operation is performed. 18. The HSD device according to claim 16, wherein the step of initiating the first operation is performed when it is determined that the person located within the limited distance range of the HSD device is the operator.