(19)
(11)EP 2 489 025 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
05.07.2017 Bulletin 2017/27

(21)Application number: 10778542.0

(22)Date of filing:  15.10.2010
(51)International Patent Classification (IPC): 
G08B 13/24(2006.01)
G01V 3/08(2006.01)
(86)International application number:
PCT/DK2010/050272
(87)International publication number:
WO 2011/044915 (21.04.2011 Gazette  2011/16)

(54)

AN ELECTRONIC ANTI-THEFT PROTECTION SYSTEM

ELEKTRONISCHES DIEBSTAHLSCHUTZSYSTEM

SYSTÈME ÉLECTRONIQUE DE PROTECTION ANTIVOL


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 16.10.2009 DK 200970160
16.10.2009 US 200961272659 P

(43)Date of publication of application:
22.08.2012 Bulletin 2012/34

(73)Proprietor: Alert Systems ApS
2970 Hørsholm (DK)

(72)Inventors:
  • SOERENSEN, Soeren
    I-22020 Fagetto Lario (IT)
  • FALKENBERG, Verner
    DK-2300 Copenhagen S (DK)

(74)Representative: Zacco Denmark A/S 
Arne Jacobsens Allé 15
2300 Copenhagen S
2300 Copenhagen S (DK)


(56)References cited: : 
EP-A1- 0 736 850
WO-A2-2007/101317
US-A- 3 971 983
US-A- 6 133 829
US-B1- 6 541 966
WO-A1-2008/028487
GB-A- 2 154 350
US-A- 4 859 991
US-A1- 2004 147 833
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The invention relates to an electronic system for anti-theft protection of goods, said system comprising: a unit for detecting a metallic material in a detection zone; a unit for detecting a magnetic or magnetisable material in a detection zone; and a control unit.

    [0002] Today, anti-theft protection of goods in eg stores or supermarkets is accomplished to a wide extent by tagging of the individual goods. The known systems for preventing theft usually comprise the so-called anti-theft tokens that are attached to the goods in the shop.

    [0003] In clothing shops, the anti-theft protection is often constituted of a two-part anti-theft token, wherein the one part comprises a pin which is inserted through the item of clothes and locked to the other part of the anti-theft protection. Moreover the anti-theft token contains a unit that can be detected by an anti-theft arrangement located at the exit of the shop. The lock in the anti-theft token is released by means of a magnet, a so-called releaser, and that release is intended to take place at the cash-register following purchase of the item of clothing.

    [0004] However, it is now a problem that shoplifters bring a magnet/releaser and, by means thereof, take off the anti-theft token to the effect that the anti-theft arrangement is unable to detect a stolen item when the item passes by the anti-theft arrangement. This is typically done in areas of the shop, where, for the sake of decency, the customers are not monitored visually, eg in fitting rooms or lavatories.

    [0005] Protection of goods against theft can also be accomplished by means of eg a coil, a magnet, or a small radio transmitter which is contained in stickers on the goods and has the particular ability of containing information, without battery, which is released when it passes a magnetic field or is exposed to a radio signal. By tagging each individual item in eg a supermarket with this kind of anti-theft protection, it is thus also possible to record whether goods that are not paid for pass by selected points. This is typically done at the cash-registers or the exits as such of the shops.

    [0006] However, professional thieves have long been aware that such electronic anti-theft protections can be circumvented by shielding the stolen goods from the surroundings by means of a radiation shield, a so-called "Faraday cage" which eliminates all electric influence from the outside or from within. Usually this takes place quite simply by insulating eg a carrier bag or a rucksack/bag with an interior layer of a conductive material, such as eg tinfoil, but, in principle any conductive material can be used. Such insulated receptacle efficiently prevents any detection of tagged goods contained therein and therefore it also prevents discovery of any stolen goods that may be present in the insulated container, and therefore such insulated receptacles, in everyday terms designated "booster bags", are also the direct cause of a considerable loss of goods in ia the retail trade.

    [0007] Therefore, today metal detectors have also been introduced that are capable of detecting such "booster bags", and today an efficient anti-theft protection of goods consists of both sensors for detecting the signals that are emitted from the tagged goods and metal detectors for detecting "booster bags".

    [0008] Metal detectors are commonly known to the person skilled in the art and may be made eg as described in US 6,133,829, JP 8 050 690 or EP 0 736 850, and therefore their functionalities will not be described in further detail.

    [0009] Magnet detectors are also well-known to the person skilled in the art and may be made eg as described in US 3,971,983.

    [0010] However, ordinary trolleys of steel constitute a problem as they are also detected by the metal detectors which are therefore caused to emit "false alarms" each time a trolley passes a metal detector.

    [0011] There is therefore a need for a system that minimises the above drawbacks.

    [0012] This is accomplished by the control unit according to claim 1. Hereby an improved anti-theft protection system is accomplished which may prevent false alarms.

    [0013] Embodiments of the invention will be provided in the independent claims.
    The tem "metallic material" is to be construed as comprising means that are usually considered to be amagnetic, including but not restricted to eg tinfoil, aluminium, austenitic stainless steel or gold and silver. Those materials may be detected by means of metal detectors, but not by detectors that sense magnetic/magnetisable materials. By magnetic materials is to be understood materials that can be magnetised, including iron (Fe), nickel (Ni) and cobalt (Co).

    [0014] The terms "sensing device, sensor or detector" are to be construed as electronic apparatuses that may, in given situations, give deflections when detecting/measuring magnetic or metallic objects within a given volume/area which may ensuingly be designated the detection zone and/or sensing/measuring area.

    [0015] Programming is not to be construed as something which is necessarily software-related; rather it may also mean that one merely moves to wires in a series of switches.

    [0016] In the following, an embodiment of the invention will be explained with reference to the figures, wherein

    Figure 1 is a schematic drawing of the earth's magnetic field;

    Figure 2 shows, seen from above and schematically, how the earth's magnetic field is changed by a car;

    Figure 3 shows, seen from the side and in a schematic view, how the earth's magnetic field is changed by a car;

    Figure 4 is a schematic drawing showing the functionality of a magnetic sensor;

    Figures 5A-5D schematically show how a customer wearing a rucksack passes by an embodiment of a system according to the invention.



    [0017] Figure 1 shows a drawing of the earth's magnetic field as it runs between the North Pole and the South Pole, and the invention contains a sensor that registers the changes thereto. Such sensors are known and used today in a version capable of measuring changes to the magnetic field in three dimensions, eg for electronic compasses for use in airplanes, mobile phones, measurement of current in a wire, or for traffic detection.

    [0018] Thus, the sensor may measure magnetic fields from permanent magnets (eg the earth's magnetic field) and electromagnetic fields generated by a current (ac or dc) in a wire.

    [0019] Figures 2 and 3 schematically show how such sensors (10) that are deployed in a roadway may measure the changes to the earth's magnetic field when a car passes by.

    [0020] Figure 4 shows an example of registering a moving magnet.

    [0021] The invention relates to a system containing both such "magnetic" sensor and a sensor capable of detecting metallic materials by means of two antennae (1x transmitter (TX) and 1x receiver (RX)) that are typically arranged as a gate eg at the entrance or the exit of a shop. The metal sensor registers all types of metal of a given size and volume. The known anti-theft systems contain only a metal detector and the purpose of that is to register the passing by of bags, rucksacks, bags or the like that are insulated/lined with eg aluminium foil. It is a drawback of those systems that trolleys are also detected by this system and they may consequently be a source of false alarms.

    [0022] By combining a magnetic sensor with a sensor capable of detecting metallic materials, a system is accomplished where the control unit may be programmed to give different deflections depending on whether it is a bag lined with aluminium or a trolley that travels through a zone in which both sensors make measurements. If it is such a bag, only the metal detector will give deflections, whereas both metal detector and magnetic detector will give deflections if a trolley of iron passes through the common detection zone of the sensors. As mentioned above, the metal sensor detects - depending on its setting - only metallic material above a certain size and it is consequently possible to pass by it with a bundle of keys or a magnet in one's pocket without the metal sensor registering it.

    [0023] By providing the system with a suitable control unit, the system can thus be programmed to emit alarms eg only if registration is accomplished of either rmagnetic material, amagnetic metallic material or both in a shared measurement area (detection zone). Thereby a system is accomplished which is - as a minimum - capable of differentiating between three situations:
    1. 1. A booster bag which is lined with eg aluminium foil, since only the metal detector will respond to it;
    2. 2. A magnet, since only the magnet sensor will sense it;
    3. 3. A trolley since both sensor types will register it.


    [0024] Usually, the system's control unit will be programmed such that the system does not emit an alarm when trolleys pass by the system; ie when both sensors register an item (situation 3 above).

    [0025] Figures 5A-5D show an embodiment of a system according to the invention which a person wearing a rucksack passes by. The system comprises two antennae (1, 2) arranged such that the customers have to pass there between.

    [0026] In each of the two antenna systems (1, 2) magnet sensors (3) and metal detectors (1, 2), respectively are arranged; however, neither of them are, in the shown embodiment, shown in detail - and the sensors are arranged such that they have a coinciding measurement area. Thus, both sensor types will register when the trolley enters the shared measurement zone, see optionally figure 5B (situation 3 above) and, as mentioned above, the system will normally be set such that, in this situation, the control unit does not emit an alarm.

    [0027] Then, the system will register that the trolley leaves the measurement area, see optionally figure 5D, as the magnet sensor will stop detecting its presence, whereas only the metal detector/sensor will register the rucksack - if it is lined with eg aluminium foil - while being in the measurement area as shown in Figure 5D (situation 1 above), and here the control unit is to emit an alarm to the effect that a metal object/a booster bag is present.

    [0028] If, instead of a lined rucksack, the customer brings in a magnet, the sequence will be to first register a trolley (situation 3) and then to register magnetic material/a magnet (situation 2), and here the control unit is to emit an alarm.

    [0029] By a three-axis magnetic sensor/sensing device, it is possible to calculate an angle relative to the magnetic object moving through the gate. This means that it is possible to measure the direction in which the magnetic object moves through the gate.

    [0030] Moreover, it is possible to arrange a three-axis magnetic sensor in each antenna. This provides the option of calculating the angle from each of the magnetic sensors/sensor devices to the magnetic object and hence to make a cross-bearing. In this way, the location or even the velocity of a detected object may be determined. The control unit may furthermore be programmed such that it disregards situations where the velocity or the position of this object is in an area which is unrealistic for an object transported by a customer.

    [0031] By combining the information from the two sensor systems, it is possible to set up a system where one may chose between different functions and properties.
    • The metal detector without magnetic detection. This system functions like the presently known systems.
    • Magnet detection without metal detection. This system is targeted to the fitting rooms of clothes shops.
    • Metal detection with magnet detection where the metal detector is used for registering a bag lined with aluminium, and the combination is used to register the trolley, and the magnetic sensor is used to detect a magnet (situation 2).


    [0032] The latter configuration may be used to advantage in the fitting rooms of clothes shops (where it is suspected that anti-theft tokens are removed by means of magnetic releasers brought along), and wherein there is a traffic flow of trolleys and/or prams.

    [0033] Thus, the system may be configured in the following ways:
    MetalMagneticCombiEventMetal SystemMagnetic system
    On/offOn/offOn/offPassage through or in proximity of gate(s)  
        MetalMagnetic
    1 2 3      
    ON OFF OFF Booster bag Yes OFF
    ON OFF OFF Trolley Yes OFF
    ON OFF OFF Magnet No OFF
    ON OFF OFF Booster bag + magnet Yes OFF


    [0034] In the above configuration the magnet detection system is off and the system serves as a conventional metal detection system.
    MetalMagneticCombiEventMetal SystemMagnetic system
    On/offOn/offOn/offPassage through or in proximity of gate(s)  
        MetalMagnetic
    1 2 3      
    OFF ON OFF Booster bag OFF No
    OFF ON OFF Trolley OFF Yes
    OFF ON OFF Magnet OFF Yes
    OFF ON OFF Booster bag + magnet OFF Yes


    [0035] In the above configuration, the metal detection system is off, and the system serves as system capturing magnetic material.
    MetalMagneticCombiEventMetal SystemMagnetic system
    On/offOn/offOn/offPassage through or in proximity of gate(s)  
        MetalMagnetic
    1 2 3      
    ON ON OFF Booster bag Yes No
    ON ON OFF Trolley Yes Yes
    ON ON OFF Magnet No Yes
    ON ON OFF Booster bag + magnet Yes Yes


    [0036] In the above configuration, both the metal detection system and the magnet detection system is on, and by programming of the control the system may hereby respond on either of:
    • Booster bags as they will give unequivocal information from the detectors/sensors, viz. positive deflection for metal simultaneously with negative deflection for magnetic material.
    • Magnets as they will give unequivocal information from the detectors/sensors, viz positive deflection for magnetic material simultaneously with negative deflection for metals.
    • Booster bags with magnets and/or shopping carts/trolleys, as both give positive deflections for both magnetic material and metals.


    [0037] In normal conditions, one would program the control such that, like the prior art systems, alarm is given on booster bags, but, as opposed to earlier systems, it is possible by the present invention to provide a system that can also be used to emit alarm in case of magnets passing by. And also a system which omits to emit an alarm when trolleys pass by.

    [0038] The invention is not restricted to the embodiment shown, but is set forth in the claims.


    Claims

    1. An electronic system for anti-theft protection of goods, said system comprising:

    • a unit for detecting a metallic material in a detection zone;

    • a unit for detecting a magnetic or magnetisable material in a detection zone;and

    • a control unit, the control unit is capable of receiving information from the units for detecting metallic and magnetic material when the one or both of these units detect a metallic or a magnetic material, respectively, in a shared detection zone, and by the control unit being programmed to:

    - emit an alarm which depends on whether it receives information about the detection of metallic or magnetic material;

    - emit an alarm when it receives information about the detection of a metallic material, while simultaneously it does not receive information about the detection of magnetic materials,and characterized in that

    - the system's control unit is programmed such that the system does not emit an alarm when both sensors register an item.


     
    2. An electronic system for anti-theft protection of goods according to claim 1, characterised in that the control unit emits an alarm when the control unit does not receive information on detection of metallic material simultaneously with it receiving information about the detection of magnetic material in a zone in which it is possible to detect both magnetic and metallic material.
     
    5. An electronic system for anti-theft protection of goods according to claims 1 - 4, characterised in that the unit for detecting a magnetic material comprises a unit which is capable of detecting changes to the earth's magnetic field.
     
    6. An electronic system for anti-theft protection of goods according to claims 1 - 5, characterised in that the unit for detecting a magnetic material comprises a unit which is capable of detecting changes to the earth's magnetic field in three dimensions.
     
    7. An electronic system for anti-theft protection of goods according to claims 1 - 6, characterised in that the system comprises at least two units for detecting a magnetic material; and that these units may each separately detect changes to the earth's magnetic field in three dimensions.
     
    8. An electronic system for anti-theft protection of goods according to claims 1 - 7, characterised in that the system comprises at least two units for detecting a magnetic material; and that these units may each separately detect changes to the earth's magnetic field in three dimensions; and that these units are arranged relative to each other such that the position of a magnetic/magnetisable material in their shared detection zone can be estimated by the control unit.
     
    9. An electronic system for anti-theft protection of goods according to claim 8, characterised in that the system comprises at least two units for detecting a magnetic material; and that these units may each separately detect changes to the earth's magnetic field in three dimensions; and that these units are arranged relative to each other such that the velocity of a magnetic/magnetisable material in their shared detection zone can be estimated by the control unit.
     
    10. An electronic system for anti-theft protection of goods according to claim 9, characterised in that the system comprises a display; and that the display provides information on whether the units for detecting a metallic and magnetic material detect those materials.
     


    Ansprüche

    1. Elektronisches System zum Diebstahlschutz von Waren, welches System umfasst:

    • eine Einheit zum Erkennen eines metallischen Materials in einer Erkennungszone;

    • eine Einheit zum Erkennen eines magnetischen oder magnetisierbaren Materials in einer Erkennungszone; und

    • eine Steuereinheit,

    die Steuereinheit ist dazu fähig, Informationen von den Einheiten zum Erkennen metallischen und magnetischen Materials zu empfangen, wenn die eine oder die beiden dieser Einheiten in einer gemeinsamen Erkennungszone ein metallisches bzw. ein magnetisches Material erkennt oder erkennen, und wobei die Steuereinheit dazu programmiert ist:

    - abhängig davon, ob sie Informationen über das Erkennen metallischen oder magnetischen Materials empfängt, einen Alarm auszulösen;

    - einen Alarm auszulösen, wenn sie Informationen über das Erkennen eines metallischen Materials empfängt, während sie gleichzeitig keine Informationen über das Erkennen von magnetischen Materialien empfängt, und

    dadurch gekennzeichnet, dass

    - die Steuereinheit des Systems derart programmiert ist, dass das System keinen Alarm auslöst, wenn beide Sensoren ein Objekt erfassen.


     
    2. Elektronisches System zum Diebstahlschutz von Waren nach Anspruch 1, dadurch gekennzeichnet, dass die Steuereinheit einen Alarm auslöst, wenn die Steuereinheit keine Informationen über das Erkennen metallischen Materials empfängt, gleichzeitig damit, dass sie Informationen über das Erkennen magnetischen Materials in einer Zone empfängt, in welcher das Erkennen von sowohl magnetischem als auch metallischem Material möglich ist.
     
    3. Elektronisches System zum Diebstahlschutz von Waren nach Anspruch 1-2, dadurch gekennzeichnet, dass die Einheit zum Erkennen eines magnetischen Materials eine Einheit umfasst, welche Änderungen des Erdmagnetfeldes erkennen kann.
     
    4. Elektronisches System zum Diebstahlschutz von Waren nach Anspruch 1-3, dadurch gekennzeichnet, dass die Einheit zum Erkennen eines magnetischen Materials eine Einheit umfasst, welche Änderungen des Erdmagnetfeldes in drei Dimensionen erkennen kann.
     
    5. Elektronisches System zum Diebstahlschutz von Waren nach Anspruch 1-4, dadurch gekennzeichnet, dass das System mindestens zwei Einheiten zum Erkennen eines magnetischen Materials umfasst; und dass diese Einheiten jede für sich Änderungen des Erdmagnetfeldes in drei Dimensionen erkennen können.
     
    6. Elektronisches System zum Diebstahlschutz von Waren nach Anspruch 1-5, dadurch gekennzeichnet, dass das System mindestens zwei Einheiten zum Erkennen eines magnetischen Materials umfasst; und dass diese Einheiten jede für sich Änderungen des Erdmagnetfeldes in drei Dimensionen erkennen können; und dass diese Einheiten relativ zueinander derart angeordnet sind, dass die Position eines magnetischen/magnetisierbaren Materials in ihrer gemeinsamen Erkennungszone durch die Steuereinheit ausgewertet werden kann.
     
    7. Elektronisches System zum Diebstahlschutz von Waren nach Anspruch 6, dadurch gekennzeichnet, dass das System mindestens zwei Einheiten zum Erkennen eines magnetischen Materials umfasst; und dass diese Einheiten jede für sich Änderungen des Erdmagnetfeldes in drei Dimensionen erkennen können; und dass diese Einheiten relativ zueinander derart angeordnet sind, dass die Geschwindigkeit eines magnetischen/magnetisierbaren Materials in ihrer gemeinsamen Erkennungszone durch die Steuereinheit ausgewertet werden kann.
     
    8. Elektronisches System zum Diebstahlschutz von Waren nach Anspruch 7, dadurch gekennzeichnet, dass das System eine Anzeige umfasst; und dass die Anzeige Informationen darüber, ob die Einheiten zum Erkennen eines metallischen und magnetischen Materials diese Materialien erkennen, bereitstellt.
     


    Revendications

    1. Système électronique de protection anti-vol de marchandises, ledit système comprenant:

    • une unité de détection d'un matériau métallique dans une zone de détection;

    • une unité de détection d'un matériau magnétique ou magnétisable dans une zone de détection; et

    • une unité de commande,

    l'unité de commande est apte à recevoir des informations provenant des unités de détection de matériau métallique et magnétique lorsque l'une ou les deux de ces unités détectent un matériau respectivement métallique ou magnétique dans une zone de détection partagée, et ladite unité de commande étant programmée à:

    - émettre une alarme qui dépend de la réception d'informations concernant la détection de matériau métallique ou magnétique;

    - émettre une alarme lorsqu'elle reçoit des informations concernant la détection d'un matériau métallique, tandis qu'elle ne reçoit pas d'informations concernant la détection de matériaux métalliques, et

    caractérisé en ce que

    - l'unité de commande du système est programmée si bien que le système n'émet pas une alarme lorsque les deux capteurs détectent un objet.


     
    2. Système électronique de protection anti-vol de marchandises selon la revendication 1, caractérisé en ce que l'unité de commande émet une alarme lorsque l'unité de commande ne reçoit pas d'informations concernant la détection d'un matériau métallique simultanément avec la réception d'informations concernant la détection de matériau magnétique dans un zone dans laquelle il est possible de détecter des matériaux à la fois magnétiques et métalliques.
     
    3. Système électronique de protection anti-vol de marchandises selon les revendications 1 à 2, caractérisé en ce que l'unité de détection d'un matériau magnétique comprend une unité capable de détecter des changements du champ magnétique terrestre.
     
    4. Système électronique de protection anti-vol de marchandises selon les revendications 1 à 3, caractérisé en ce que l'unité de détection d'un matériau magnétique comprend une unité capable de détecter des changements du champ magnétique terrestre en trois dimensions.
     
    5. Système électronique de protection anti-vol de marchandises selon les revendications 1 à 4, caractérisé en ce que le système comprend au moins deux unités de détection d'un matériau magnétique; et que ces unités peuvent détecter chacune séparément des changements du champ magnétique terrestre en trois dimensions.
     
    6. Système électronique de protection anti-vol de marchandises selon les revendications 1 à 5, caractérisé en ce que le système comprend au moins deux unités de détection d'un matériau magnétique; et que ces unités peuvent détecter chacune séparément des changements du champ magnétique terrestre en trois dimensions; et que ces unités sont agencées de façon relative l'une par rapport à l'autre si bien que la position d'un matériau magnétique/magnétisable dans leur zone de détection partagée peut être estimée par l'unité de commande.
     
    7. Système électronique de protection anti-vol de marchandises selon la revendication 6, caractérisé en ce que le système comprend au moins deux unités de détection d'un matériau magnétique; et que ces unités peuvent détecter chacune séparément des changements du champ magnétique terrestre en trois dimensions; et que ces unités sont agencées de façon relative l'une par rapport à l'autre si bien que la vélocité d'un matériau magnétique/magnétisable dans leur zone de détection partagée peut être estimée par l'unité de commande.
     
    8. Système électronique de protection anti-vol de marchandises selon la revendication 7, caractérisé en ce que le système comprend un dispositif d'affichage; et que le dispositif d'affichage indique si les unités de détection d'un matériau métallique et magnétique détectent ces matériaux.
     




    Drawing














    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description