EP0789340A1 - Security element for electronic article surveillance - Google Patents
Security element for electronic article surveillance Download PDFInfo
- Publication number
- EP0789340A1 EP0789340A1 EP97100501A EP97100501A EP0789340A1 EP 0789340 A1 EP0789340 A1 EP 0789340A1 EP 97100501 A EP97100501 A EP 97100501A EP 97100501 A EP97100501 A EP 97100501A EP 0789340 A1 EP0789340 A1 EP 0789340A1
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- EP
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- Prior art keywords
- magnetic material
- hard
- securing element
- barkhausen effect
- semi
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2405—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used
- G08B13/2408—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used using ferromagnetic tags
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- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2428—Tag details
- G08B13/2437—Tag layered structure, processes for making layered tags
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- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2428—Tag details
- G08B13/2437—Tag layered structure, processes for making layered tags
- G08B13/2442—Tag materials and material properties thereof, e.g. magnetic material details
Definitions
- the invention relates to a security element for electronic article security, consisting of a material of high permeability and low coercive force (soft magnetic material) which, when an external magnetic alternating field is applied in a query zone, emits a characteristic signal which can be detected by means of a detector device.
- a security element for electronic article security consisting of a material of high permeability and low coercive force (soft magnetic material) which, when an external magnetic alternating field is applied in a query zone, emits a characteristic signal which can be detected by means of a detector device.
- the characteristic signal therefore occurs periodically with the frequency of the low-frequency field.
- harmonic detection system it has also become known to use only a query field in the kHz range for excitation of the fuse element, the characteristic signal of the fuse element again in the cycle of a low-frequency field, which points the soft magnetic material between the two saturations - and drives, occurs.
- the shape of the characteristic signal is then compared with a predetermined signal shape. If the two agree, this is interpreted as an illegal stay of a secured article in the query zone; an alarm indicates the theft to the operating personnel.
- the hysteresis curves of securing elements which are made of a soft magnetic material have an essentially linear course between the two saturation states.
- securing elements have also become known whose hysteresis curves show a sudden transition between the two saturation states as soon as they are forced to change their direction of saturation by an external magnetic field.
- Materials with a discontinuous transition behavior between the two saturation states are referred to as "materials with a high Barkhausen effect”.
- materials with a high Barkhausen effect Materials with a discontinuous transition behavior between the two saturation states.
- the properties of these materials and the physical principles of the Barkhausen effect are described in detail in US Pat. No. 4,660,025 or also in EP 0 448 114 A1.
- the cited prior art documents refer to how physical special treatment of soft magnetic material can convert it into a material with a high Barkhausen effect.
- the Barkhausen effect can be intensified if a soft magnetic material is arranged in the vicinity of the material with the Barkhausen effect in such a way that the stray fields of the two materials couple.
- the signal of a correspondingly prepared security element is so strong that it is reliably detected in the interrogation zone of a detection system with relatively small dimensions of the materials used.
- Fuse elements of the type described above are characterized by a characteristic signal which blatantly deviates from the signal form recognizable in a harmonic detection system.
- the consequence of this is that an article which carries a soft magnetic material and a material with a high Barkhausen effect as a securing element is not recognized as a secured article in a harmonic detection system. Since no alarm is subsequently triggered, the article can pass through the query zone unhindered despite electronic security.
- the invention has for its object to modify a security element, which is composed of a soft magnetic material and a material with a high Barkhausen effect, in such a way that it is recognized by a harmonic detection system.
- the object is achieved in that, in addition to the soft magnetic material and the material with a high Barkhausen effect - the material with the high Barkhausen effect with respect to the soft magnetic material being arranged in such a way that both are coupled via their stray fields - a semi-hard or hard magnetic material is provided which pre-magnetizes the material with the high Barkhausen effect.
- the characteristic signal of the material with the high Barkhausen effect is suppressed by the solution according to the invention.
- An article provided with a security element according to the invention can therefore be detected in the monitoring zone of a harmonic detection system.
- the effect can be reversed by appropriate demagnetization of the semi-hard or hard magnetic material, ie the security elements according to the invention can be used both for harmonic detection systems and for detection systems for security elements with a Barkhausen effect.
- the soft magnetic material and / or the material with the high Barkhausen effect is a thin-layer material.
- Securing elements made of thin-layer materials have already become known from EP 0 295 028 B1.
- the soft magnetic material and / or the material with the high Barkhausen effect is / are strip-shaped or consists of a drawn wire.
- a thin-layer material can also be used for the semi-hard or hard magnetic material.
- An alternative embodiment proposes a perforated foil, preferably a Ni perforated foil - or a ferrite layer.
- the semi-hard or hard magnetic material is arranged in individual sections.
- the sections are positioned as a quasi third layer on the material with the high Barkhausen effect, since this achieves an optimal interaction of the stray field of the semi-hard or hard magnetic material with the stray field of the material with the high Barkhausen effect. while the influence of the stray field of the soft magnetic material is relatively small.
- 'individual sections' can also mean that the semi-hard or hard magnetic material in selected areas has a low permeability in the direction of the preferred axis of the securing element.
- the semi-hard or hard magnetic material has a desired bias in one direction.
- this is expressed in such a way that the portion of the signal resulting from the material with the Barkhausen effect disappears; the signal itself is shifted in the direction of the positive or the negative time axis by the premagnetization when excited by an alternating magnetic field.
- the semi-hard or hard magnetic material In order to prevent this time shift in the occurrence of the characteristic signal, it has proven to be particularly expedient for the semi-hard or hard magnetic material to have selected sections which are premagnetized in opposite directions, preferably two sections with opposite magnetization lying next to one another. This makes it possible to compensate for temporal shifts, such as occur in one direction in the case of the configuration with a premagnetization.
- the detection system should subsequently of course no longer trigger an alarm.
- the semi-hard or hard magnetic material is selected such that, in the saturated state, it prevents the characteristic signal of the soft magnetic material and the material with the high Barkhausen effect in the question zone.
- the deactivator material must be exposed to a magnetic field so strong that it is driven into saturation. As a result of the deactivation, the characteristic signal is moved out of the time range under consideration and can subsequently no longer be registered by the detection system.
- FIG. 2a shows the hysteresis curve 3 which results when the stray fields 7 of the two materials 1, 2 couple with one another.
- the four boxes with the arrows each indicate the direction of magnetization of the soft magnetic material 1 and the material with the high Barkhausen effect 2.
- both the soft magnetic material 1 and the material with the high Barkhausen effect 2 are magnetized in one direction.
- the soft magnetic material 1 first changes its magnetization direction.
- the stray field 7 of the soft magnetic material 1 interacting with the stray field 7 of the material with the high Barkhausen effect 2 delays the sudden magnetic reversal of the material with the high Barkhausen effect 2: the hysteresis curve 3 is partly linear, partly it shows a sudden change.
- the resulting characteristic signal 4 has the shape shown in FIG. 2b.
- This characteristic signal 4 differs from the characteristic signal 4, which is emitted by a soft magnetic material 1 in response to an interrogation field (see FIG. 3c), by an asymmetrical double peak.
- This form of the characteristic signal 4 is not recognized in a harmonic detection system as originating from an electronically secured article.
- FIG. 3a A first embodiment of the securing element 8 according to the invention can be seen in FIG. 3a.
- the securing element 8 consists of a soft magnetic material 1, a material arranged above it with a high Barkhausen effect 2 and of individual sections of a semi-hard or hard magnetic material 6.
- the sections of the semi-hard or hard magnetic material 6 are pre-magnetized in such a way that, in particular, the spatially closer one Stray field 7 of the material with the high Barkhausen effect 2 is affected.
- the interaction with the stray field 7 of the semi-hard or hard magnetic material 6 is such that the material with the high Barkhausen effect 2 does not make any signal contributions in the magnetic alternating field of the query zone.
- the hysteresis curve 3 of the embodiment of the securing element 8 according to the invention shown in FIG. 3a essentially corresponds - as can be seen from FIG. 3b - to the hysteresis curve 3 of a soft magnetic material 1.
- the hysteresis curve 3 is an amount Hb in the direction of the positive H axis postponed.
- the characteristic signal 4 now shows the desired shape, which can be easily achieved by a harmonic detection system is detected and evaluated as belonging to a secured article.
- the characteristic signal 4 like the associated hysteresis curve 3, shows a shift in the direction of the time axis hzw. in the direction of the H axis. However, nothing changes in the relative spacing of the peaks 5 of the characteristic signal 4.
- the above-described displacement effect can be avoided if, as can be seen in FIG. 4a, the semi-hard or hard magnetic material 6 of the securing element 8 is premagnetized in both directions by the same amount.
- FIG. 4b shows the resulting hysteresis curve 3 of the securing element according to the invention, which is symmetrical to the coordinate origin and which is recorded in FIG. 4a.
Abstract
Description
Die Erfindung betrifft ein Sicherungselement zur elektronischen Artikelsicherung, bestehend aus einem Material hoher Permeabilität und geringer Koerzitivkraft (weichmagnetisches Material), das bei Anlegen eines äußeren magnetischen Wechselfeldes in einer Abfragezone ein charakteristisches Signal aussendet, welches mittels einer Detektoreinrichtung erkennbar ist.The invention relates to a security element for electronic article security, consisting of a material of high permeability and low coercive force (soft magnetic material) which, when an external magnetic alternating field is applied in a query zone, emits a characteristic signal which can be detected by means of a detector device.
Sicherungselemente der zuvor beschriebenen Art werden vielfach in Warenhäusern eingesetzt. Zur Erzielung einer hohen Detektionsrate werden ausgeklügelte Verfahren eingesetzt, die die Gefahr von Fehlalarmen effektiv herabsetzen. So ist aus der EP 123 586 B bekannt geworden, zusätzlich zu zwei Abfragefelder mit den Frequenzen f1 und f2 im kHz-Bereich ein Feld mit einer im Hz-Bereich liegenden Frequenz in die Abfragezone zu senden. Die beiden Abfragefelder mit den Frequenzen f1 und f2 regen ein in der Abfragezone befindliches Sicherungselement zur Remission eines charakteristischen Signals mit den Intermodulationsfrequenzen n·f1 ± m·f2 (n, m = 0, 1, 2,...) an. Das niederfrequente Abfragefeld bewirkt, daß das Sicherungselement im Takt dieses Feldes von der Sättigung in eine Richtung zur Sättigung in die andere Richtung getrieben wird. Das charakteristische Signal tritt daher periodisch mit der Frequenz des niederfrequenten Feldes auf.
Als alternative Lösung eines sog. harmonischen Detektionssystems ist auch bekannt geworden, lediglich ein im kHz-Bereich liegendes Abfragefeld zur Erregung des Sicherungselementes zu verwenden, wobei das charakteristische Signal des Sicherungselementes wiederum im Takte eines niederfrequenten Feldes, das das weichmagnetische Material zwischen den beiden Sättigungen hin- und hertreibt, auftritt.Securing elements of the type described above are widely used in department stores. Sophisticated methods are used to achieve a high detection rate, which effectively reduce the risk of false alarms. It has become known from EP 123 586 B to send a field with a frequency in the Hz range to the query zone in addition to two query fields with the frequencies f1 and f2 in the kHz range. The two query fields with the frequencies f1 and f2 excite a security element located in the query zone for the remission of a characteristic signal with the intermodulation frequencies n * f1 ± m * f2 (n, m = 0, 1, 2, ...). The low-frequency interrogation field causes the securing element to be driven from saturation in one direction to saturation in the other direction in time with this field. The characteristic signal therefore occurs periodically with the frequency of the low-frequency field.
As an alternative solution to a so-called harmonic detection system, it has also become known to use only a query field in the kHz range for excitation of the fuse element, the characteristic signal of the fuse element again in the cycle of a low-frequency field, which points the soft magnetic material between the two saturations - and drives, occurs.
Zwecks Auswertung wird die Form des charakteristischen Signals anschließend mit einer vorgegebenen Signalform verglichen. Stimmen beide überein, wird dies als unerlaubter Aufenthalt eines gesicherten Artikels in der Abfragezone interpretiert; ein Alarm zeigt dem Bedienpersonal den Diebstahl an.For the purpose of evaluation, the shape of the characteristic signal is then compared with a predetermined signal shape. If the two agree, this is interpreted as an illegal stay of a secured article in the query zone; an alarm indicates the theft to the operating personnel.
Die Hysteresekurven von Sicherungselementen, die aus einem weichmagnetischen Material gefertigt sind, weisen zwischen den beiden Sättigungszuständen einen im wesentlichen linearen Verlauf auf. Daneben sind auch Sicherungselemente bekannt geworden, deren Hysteresekurven einen sprunghaften Übergang zwischen den beiden Sättigungszuständen zeigen, sobald sie über ein äußeres Magnetfeld zur Änderung ihrer Sättigungsrichtung gezwungen werden. Materialien mit einem unstetigen Übergangsverhalten zwischen den beiden Sättigungszuständen werden als "Materialien mit hohem Barkhauseneffekt" bezeichnet.
Beispielsweise werden die Eigenschaften dieser Materialien sowie die physikalischen Grundlagen des Barkhauseneffekts ausführlich in der US-PS 4,660,025 oder auch in der EP 0 448 114 A1 beschrieben. Insbesondere wird in den zitierten Schriften des Standes der Technik Bezug darauf genommen, wie durch physikalische Spezialbehandlung von weichmagnetischem Materials dieses in ein Material mit einem hohen Barkhauseneffekt überführt werden kann.The hysteresis curves of securing elements which are made of a soft magnetic material have an essentially linear course between the two saturation states. In addition, securing elements have also become known whose hysteresis curves show a sudden transition between the two saturation states as soon as they are forced to change their direction of saturation by an external magnetic field. Materials with a discontinuous transition behavior between the two saturation states are referred to as "materials with a high Barkhausen effect".
For example, the properties of these materials and the physical principles of the Barkhausen effect are described in detail in US Pat. No. 4,660,025 or also in EP 0 448 114 A1. In particular, the cited prior art documents refer to how physical special treatment of soft magnetic material can convert it into a material with a high Barkhausen effect.
Weiterhin ist aus dem Stand der Technik bekannt geworden, daß sich der Barkhauseneffekt verstärken läßt, wenn in der Nahe des Materials mit dem Barkhauseneffekt ein weichmagnetisches Material derart angeordnet wird, daß die Streufelder beider Materialien koppeln. Das Signal eines entsprechend präparierten Sicherungselementes ist so stark, daß es bei relativ geringen Dimensionierungen der verwendeten Materialien verläßlich in der Abfragezone eines Detektionssystems erfaßt wird.Furthermore, it has become known from the prior art that the Barkhausen effect can be intensified if a soft magnetic material is arranged in the vicinity of the material with the Barkhausen effect in such a way that the stray fields of the two materials couple. The signal of a correspondingly prepared security element is so strong that it is reliably detected in the interrogation zone of a detection system with relatively small dimensions of the materials used.
Sicherungselemente der zuvor beschriebenen Art zeichnen sich jedoch durch ein charakteristisches Signal aus, das eklatant von der in einem harmonischen Detektionssystem erkennbaren Signalform abweicht. Die Folge hiervon ist, daß ein Artikel, der als Sicherungselement ein weichmagnetisches Material und ein Material mit hohem Barkhauseneffekt trägt, in einem harmonischen Detektionssystem nicht als gesicherter Artikel erkannt wird. Da nachfolgend kein Alarm ausgelöst wird, kann der Artikel trotz elektronischer Sicherung die Abfragezone ungehindert passieren.Fuse elements of the type described above, however, are characterized by a characteristic signal which blatantly deviates from the signal form recognizable in a harmonic detection system. The consequence of this is that an article which carries a soft magnetic material and a material with a high Barkhausen effect as a securing element is not recognized as a secured article in a harmonic detection system. Since no alarm is subsequently triggered, the article can pass through the query zone unhindered despite electronic security.
Der Erfindung liegt die Aufgabe zugrunde, ein Sicherungselement, das sich aus einem weichmagnetischen Material und einem Material mit hohem Barkhauseneffekt zusammensetzt, derart zu modifizieren, daß es von einem harmonischen Detektionssystem erkannt wird.The invention has for its object to modify a security element, which is composed of a soft magnetic material and a material with a high Barkhausen effect, in such a way that it is recognized by a harmonic detection system.
Die Aufgabe wird dadurch gelöst, daß zusätzlich zu dem weichmagnetischen Material und dem Material mit einem hohen Barkhauseneffekt - wobei das Material mit dem hohen Barkhauseneffekt bezüglich des weichmagnetischen Materials derart angeordnet ist, daß beide über ihre Streufelder gekoppelt sind - ein halbhart- oder hartmagnetisches Material vorgesehen ist, welches das Material mit dem hohen Barkhauseneffekt vormagnetisiert. Durch die erfindungsgemäße Lösung wird das charakteristische Signal des Materials mit dem hohen Barkhauseneffekt unterdrückt.The object is achieved in that, in addition to the soft magnetic material and the material with a high Barkhausen effect - the material with the high Barkhausen effect with respect to the soft magnetic material being arranged in such a way that both are coupled via their stray fields - a semi-hard or hard magnetic material is provided which pre-magnetizes the material with the high Barkhausen effect. The characteristic signal of the material with the high Barkhausen effect is suppressed by the solution according to the invention.
Ein mit einem erfindungsgemäßen Sicherungselement versehener Artikel ist daher in der Überwachungszone eines harmonischen Detektionssystems detektierbar.
Selbstverständlich ist der Effekt durch entsprechende Entmagnetisierung des halbhart- oder hartmagnetischen Materials wieder umkehrbar, d.h., daß die erfindungsgemäßen Sicherungselemente sowohl für harmonische Detektionssysteme als auch für Detektionssysteme für Sicherungselemente mit Barkhauseneffekt brauchbar sind.An article provided with a security element according to the invention can therefore be detected in the monitoring zone of a harmonic detection system.
Of course, the effect can be reversed by appropriate demagnetization of the semi-hard or hard magnetic material, ie the security elements according to the invention can be used both for harmonic detection systems and for detection systems for security elements with a Barkhausen effect.
Gemäß einer vorteilhaften Weiterbildung des erfindungsgemäßen Sicherungselementes ist vorgesehen, daß es sich bei dem weichmagnetischen Material und/oder bei dem Material mit dem hohen Barkhauseneffekt um ein Dünnschichtmaterial handelt. Sicherungselemente aus Dünnschichtmaterialien sind bereits aus der EP 0 295 028 B1 bekannt geworden. Selbstverständlich ist es ebenfalls möglich, daß das weichmagnetischen Material und/oder das Material mit dem hohen Barkhauseneffekt streifenförmig ausgebildet ist/sind oder aus einem gezogenen Draht besteht/bestehen.According to an advantageous development of the securing element according to the invention, it is provided that the soft magnetic material and / or the material with the high Barkhausen effect is a thin-layer material. Securing elements made of thin-layer materials have already become known from EP 0 295 028 B1. Of course, it is also possible that the soft magnetic material and / or the material with the high Barkhausen effect is / are strip-shaped or consists of a drawn wire.
Bei dem halbhart- oder hartmagnetischen Material kann ebenfalls ein Dünnschichtmaterial verwendet werden.
Alternative Ausgestaltung schlagen eine Lochfolie, vorzugsweise eine Ni-Lochfolie - oder eine Ferritschicht vor.A thin-layer material can also be used for the semi-hard or hard magnetic material.
An alternative embodiment proposes a perforated foil, preferably a Ni perforated foil - or a ferrite layer.
Besonders günstig ist es, wenn die Anordnung von weichmagnetischem Material und Material mit hohem Barkhauseneffekt so gewählt ist, daß beide zumindest teilweise überlappen. Durch diese Ausführungsform wird auf eine einfache und kostengünstige Weise eine ausreichend starke Wechselwirkung zwischen den Streufeldern der beiden Materialien sichergestellt.It is particularly expedient if the arrangement of soft magnetic material and material with a high Barkhausen effect is selected such that both overlap at least partially. This embodiment ensures a sufficiently strong interaction between the stray fields of the two materials in a simple and inexpensive manner.
Gemäß einer vorteilhaften Weiterbildung des erfindungsgemäßen Sicherungselementes ist vorgesehen, daß das halbhart- oder hartmagnetische Material in einzelnen Abschnitten angeordnet ist. Wiederum hat es sich als günstig herausgestellt, wenn die Abschnitte als quasi dritte Schicht auf dem Material mit dem hohen Barkhauseneffekt positioniert sind, da hierdurch eine optimale Wechselwirkung des Streufeldes des halbhart- oder hartmagnetischen Materials mit dem Streufeld des Materials mit dem hohen Barkhauseneffekt erzielt wird, während die Beeinflussung des Streufeldes des weichmagnetischen Materials relativ gering ist. 'Einzelne Abschnitte' kann neben der wörtlichen Auslegung auch bedeuten, daß das halbhart- oder hartmagnetische Material in ausgewählten Bereichen eine geringe Permeabiliät in Richtung der Vorzugsachse des Sicherungselementes aufweist.According to an advantageous development of the securing element according to the invention it is provided that the semi-hard or hard magnetic material is arranged in individual sections. Again, it has proven to be advantageous if the sections are positioned as a quasi third layer on the material with the high Barkhausen effect, since this achieves an optimal interaction of the stray field of the semi-hard or hard magnetic material with the stray field of the material with the high Barkhausen effect. while the influence of the stray field of the soft magnetic material is relatively small. In addition to the literal interpretation, 'individual sections' can also mean that the semi-hard or hard magnetic material in selected areas has a low permeability in the direction of the preferred axis of the securing element.
Eine vorteilhafte Ausgestaltung sieht vor, daß das halbhart- oder hartmagnetische Material eine gewünschte Vormagnetisierung in eine Richtung aufweist. In der Form des charakteristischen Signals drückt sich dies so aus, daß der Signalanteil, der von dem Material mit dem Barkhauseneffekt herrührt, verschwindet; das Signal selbst wird durch die Vormagnetisierung bei Anregung durch ein magnetisches Wechselfeld in Richtung der positiven oder der negativen Zeitachse verschoben.An advantageous embodiment provides that the semi-hard or hard magnetic material has a desired bias in one direction. In the form of the characteristic signal, this is expressed in such a way that the portion of the signal resulting from the material with the Barkhausen effect disappears; the signal itself is shifted in the direction of the positive or the negative time axis by the premagnetization when excited by an alternating magnetic field.
Um diese zeitliche Verschiebung des Auftretens des charakteristischen Signals zu unterbinden, hat es sich als besonders günstig erwiesen, daß das halbhart- oder hartmagnetische Material ausgewählte Abschnitte aufweist, die in entgegengesetzte Richtungen vormagnetisiert sind, wobei vorzugsweise jeweils zwei Abschnitte mit entgegengesetzter Magnetisierung nebeneinander liegen.
Hierdurch lassen sich zeitliche Verschiebungen, wie sie bei der Ausgestaltung mit einer Vormagnetisierung in einer Richtung auftreten, kompensieren.In order to prevent this time shift in the occurrence of the characteristic signal, it has proven to be particularly expedient for the semi-hard or hard magnetic material to have selected sections which are premagnetized in opposite directions, preferably two sections with opposite magnetization lying next to one another.
This makes it possible to compensate for temporal shifts, such as occur in one direction in the case of the configuration with a premagnetization.
Sobald ein Kunde die mit einem Sicherungselement versehene Ware ordnungsgemäß bezahlt hat, sollen das Detektionssystem nachfolgend natürlich keinen Alarm mehr auslösen. Hierzu ist das halbhart- oder hartmagnetische Material derart gewählt, daß es im gesättigten Zustand das charakteristische Signal des weichmagnetischen Materials und des Materials mit dem hohen Barkhauseneffekt in der Ahfragezone unterbindet. Um dies zu erzielen, muß das Deaktivatormaterial also einem so starken Magnetfeld ausgesetzt werden, daß es in die Sättigung getrieben wird.
Durch die Deaktivierung wird das charakteristische Signal aus dem betrachteten Zeitbereich herausbewegt und kann nachfolgend von dem Detektionssystem nicht mehr registriert werden.As soon as a customer has properly paid for the goods provided with a security element, the detection system should subsequently of course no longer trigger an alarm. For this purpose, the semi-hard or hard magnetic material is selected such that, in the saturated state, it prevents the characteristic signal of the soft magnetic material and the material with the high Barkhausen effect in the question zone. To achieve this, the deactivator material must be exposed to a magnetic field so strong that it is driven into saturation.
As a result of the deactivation, the characteristic signal is moved out of the time range under consideration and can subsequently no longer be registered by the detection system.
Die Erfindung wird anhand der nachfolgenden Figuren näher erläutert. Es zeigt:
- Fig. 1: die Hysteresekurven eines weichmagnetischen Materials und eines Materials mit hohem Barkhauseneffekt, deren Streufelder sich nicht gegenseitig beeinflussen,
- Fig. 2a: die Hysteresekurve, die sich ergibt, wenn ein weichmagnetisches Material mit einem Material mit hohem Barkhauseneffekt wechselwirkt,
- Fig. 2b: das charakteristische Signal eines Materials mit hohem Barkhauseneffekt, das mit einem weichmagnetischen Material wechselwirkt,
- Fig. 3a: eine erste Ausführungsform des erfindungsgemäßen Sicherungselementes,
- Fig. 3b: die Hysteresekurve der in Fig. 3a gezeigten Ausführungsform,
- Fig. 3c: das charakteristische Signal des in Fig. 3a gezeigten Sicherungselementes,
- Fig. 4a: eine weitere Ausführungsform des erfindungsgemäßen Sicherungselementes und
- Fig. 4b: die Hysteresekurve des in Fig. 4a gezeigten Sicherungselementes.
- 1: the hysteresis curves of a soft magnetic material and a material with a high Barkhausen effect, the stray fields of which do not influence one another,
- 2a: the hysteresis curve that results when a soft magnetic material interacts with a material with a high Barkhausen effect,
- 2b: the characteristic signal of a material with a high Barkhausen effect, which interacts with a soft magnetic material,
- 3a: a first embodiment of the securing element according to the invention,
- 3b: the hysteresis curve of the embodiment shown in FIG. 3a,
- 3c: the characteristic signal of the fuse element shown in FIG. 3a,
- 4a: a further embodiment of the securing element according to the invention and
- 4b: the hysteresis curve of the securing element shown in FIG. 4a.
Fig. 1 zeigt die Hysteresekurven 3 eines weichmagnetischen Materials 1 und eines Materials mit hohem Barkhauseneffekt 2, wobei beide Materialien 1, 2 relativ zueinander derart angeordnet sind, daß ihre Streufelder 7 nicht miteinander wechselwirken. Aus dieser Darstellung ist klar ersichtlich, daß die Hysteresekurve 3 des weichmagnetischen Materials 1 zwischen den beiden Sättigungszuständen einen im wesentlichen linearen Verlauf aufweist, während der Übergang im Falle des Materials mit dem hohen Barkhauseneffekt 2 sprunghaft und damit nicht stetig erfolgt.1 shows the hysteresis curves 3 of a soft
In Fig. 2a ist neben den Hysteresekurven 3 eines weichmagnetischen Materials 1 und eines Materials mit einem hohen Barkhauseneffekt 2 die Hysteresekurve 3 dargestellt, die sich ergibt, wenn die Streufelder 7 der beiden Materialien 1, 2 miteinander koppeln. Die vier Kästchen mit den Pfeilen deuten jeweils die Magnetisierungsrichtung des weichmagnetischen Materials 1 und des Materials mit dem hohen Barkhauseneffekt 2 an. In den beiden Sättigungszuständen sind sowohl das weichmagnetische Material 1 als auch das Material mit dem hohen Barkhauseneffekt 2 in eine Richtung magnetisiert. In dem Übergangsbereich zwischen den beiden Sättigungszuständen ändert jeweils zuerst das weichmagnetische Material 1 seine Magnetisierungsrichtung. Das mit dem Streufeld 7 des Materials mit dem hohen Barkhauseneffekt 2 wechselwirkende Streufeld 7 des weichmagnetischen Materials 1 verzögert die sprunghafte Ummagnetisierung des Materials mit dem hohen Barkhauseneffekt 2: die Hysteresekurve 3 ist teilweise linear, teilweise zeigt sie eine sprunghaften Änderung.In addition to the hysteresis curves 3 of a soft
Als Folge der teils stetig linearen, teils sprunghaft sich ändernden Hysteresekurve 3 des Sicherungselementes 8, das aus einem weichmagnetischen Material 1 und einem Material mit hohem Barkhauseneffekt 2 besteht, hat das resultierende charakteristische Signal 4 die in Fig. 2b gezeigt Form.
Dieses charakteristische Signal 4 unterscheidet sich von dem charakteristischen Signal 4, das von einem weichmagnetischen Material 1 auf ein Abfragefeld hin ausgesendet wird (siehe Fig. 3c), durch einen asymmetrischen Doppelpeak. Diese Form des charakteristischen Signals 4 wird in einem harmonischen Detektionssystem nicht als von einem elektronisch gesicherten Artikel herrührend erkannt.As a result of the partly continuously linear, partly abruptly changing
This
In Fig. 3a ist eine erste Ausführungsform des erfindungsgemäßen Sicherungselementes 8 zu sehen. Das Sicherungselement 8 besteht aus einem weichmagnetischen Material 1, einem darüber angeordneten Material mit einem hohen Barkhauseneffekt 2 und aus einzelnen Abschnitten eines halbhart- oder hartmagnetischen Materials 6. Die Abschnitte des halbhart- oder hartmagnetischen Materials 6 sind derart vormagnetisiert, daß insbesondere das räumlich näher liegende Streufeld 7 des Materials mit dem hohen Barkhauseneffekt 2 beeinflußt wird. Die Wechselwirkung mit dem Streufeld 7 des halbhart- oder hartmagnetischen Materials 6 ist so bemessen, daß das Material mit dem hohen Barkhauseneffekt 2 in dem magnetischen Wechselfeld der Ahfragezone keine Signalheiträge leistet.A first embodiment of the securing element 8 according to the invention can be seen in FIG. 3a. The securing element 8 consists of a soft
Die Hysteresekurve 3 der in Fig. 3a gezeigten Ausführungsform des erfindungsgemäßen Sicherungselementes 8 entspricht - wie aus der Fig. 3b ersichtlich - im wesentlichen der Hysteresekurve 3 eines weichmagnetischen Materials 1. Allerdings ist die Hysteresekurve 3 um einen Betrag Hb in Richtung der positiven H-Achse verschoben. Wie bereits an vorhergehender Stelle erwähnt, zeigt das charakteristische Signal 4 nunmehr die gewünschte Form, die von einem harmonischen Detektionssystem problemlos detektiert und als zu einem gesicherten Artikel zugehörend ausgewertet wird.The
Wird das halbhart- oder hartmagnetische Material 6 lediglich in einer Richtung vormagnetisiert, so zeigt das charakteristische Signal 4 ebenso wie die dazugehörige Hysteresekurve 3 eine Verschiebung in Richtung der Zeitachse hzw. in Richtung der H-Achse. An dem relativen Abstand der Peaks 5 des charakteristischen Signals 4 ändert sich jedoch nichts. Der zuvor beschriebene Verschiebeeffekt läßt sich vermeiden, wenn - wie in Fig. 4a zu sehen - das halhhart- oder hartmagnetische Material 6 des Sicherungselementes 8 um gleichen Betrag in beide Richtungen vormagnetisiert wird.If the semi-hard or hard
Fig. 4b zeigt die resultierende, symmetrisch zum Koordinatenursprung verlaufende Hysteresekurve 3 des erfindungsgemäßen Sicherungselementes, das in Fig. 4a aufgezeichnet ist.4b shows the resulting
- 11
- weichmagnetisches Materialsoft magnetic material
- 22nd
- Material mit hohem BarkhauseneffektMaterial with a high Barkhausen effect
- 33rd
- HysteresekurveHysteresis curve
- 44th
- charakteristisches Signalcharacteristic signal
- 55
- PeakPeak
- 66
- halbhart- oder hartmagnetisches Materialsemi-hard or hard magnetic material
- 77
- StreufeldStray field
- 88th
- SicherungselementSecuring element
- HH
- magnetische Feldstärkemagnetic field strength
- BB
- magnetische Induktionmagnetic induction
- VMVM
- VormagnetisierungPremagnetization
Claims (10)
dadurch gekennzeichnet,
characterized by
dadurch gekennzeichnet,
es sich bei dem weichmagnetischen Material (1) und/oder bei dem Material mit dem hohen Barkhauseneffekt (2) um ein Dünnschichtmaterial handelt.Securing element according to claim 1,
characterized,
the soft magnetic material (1) and / or the material with the high Barkhausen effect (2) is a thin layer material.
dadurch gekennzeichnet,
characterized by
dadurch gekennzeichnet,
characterized by
dadurch gekennzeichnet,
characterized by
dadurch gekennzeichnet,
characterized by
dadurch gekennzeichnet,
characterized by
dadurch gekennzeichnet,
characterized by
dadurch gekennzeichnet,
characterized by
dadurch gekennzeichnet,
characterized by
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19604746 | 1996-02-09 | ||
DE19604746A DE19604746A1 (en) | 1996-02-09 | 1996-02-09 | Securing element for electronic article surveillance |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0789340A1 true EP0789340A1 (en) | 1997-08-13 |
EP0789340B1 EP0789340B1 (en) | 2001-07-25 |
Family
ID=7784965
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP97100501A Expired - Lifetime EP0789340B1 (en) | 1996-02-09 | 1997-01-15 | Security element for electronic article surveillance |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0789340B1 (en) |
DE (2) | DE19604746A1 (en) |
ES (1) | ES2160857T3 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0901100A2 (en) * | 1997-08-27 | 1999-03-10 | Meto International GmbH | Magnetic identification element |
EP0949598A2 (en) * | 1998-04-08 | 1999-10-13 | Meto International GmbH | Electronic anti-theft element |
WO2001078030A1 (en) * | 2000-04-07 | 2001-10-18 | Rso Corporation N.V. | A marker for remote detection of articles |
AU741785B2 (en) * | 1998-12-14 | 2001-12-06 | Meto International Gmbh | Security element for electronic article surveillance and method of manufacturing a security element |
US7469838B2 (en) | 2001-12-10 | 2008-12-30 | Brewster Kaleidoscope Llc | Detectable components and detection apparatus for detecting such components |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19730694A1 (en) * | 1997-07-17 | 1999-01-21 | Meto International Gmbh | Security element for electronic item alarm |
DE19740442A1 (en) * | 1997-09-15 | 1999-03-18 | Meto International Gmbh | Security element for item monitoring |
DE19858064A1 (en) * | 1998-12-16 | 2000-06-21 | Meto International Gmbh | Securing element for electronic article surveillance |
DE102012204660B4 (en) | 2012-03-22 | 2018-02-08 | Universität Kassel | Magnetic authenticity feature |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0153286A2 (en) * | 1984-02-15 | 1985-08-28 | Esselte Meto Eas International Ab | Method and system for detecting an indicating device |
US4660025A (en) | 1984-11-26 | 1987-04-21 | Sensormatic Electronics Corporation | Article surveillance magnetic marker having an hysteresis loop with large Barkhausen discontinuities |
EP0123586B1 (en) | 1983-03-25 | 1988-06-01 | FAIRCHILD CAMERA & INSTRUMENT CORPORATION | Tri-state driver circuit for automatic test equipment |
EP0448114A1 (en) | 1990-03-23 | 1991-09-25 | Unitika Ltd. | Thin-film magnetic material and process of production thereof |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4980670A (en) * | 1987-11-04 | 1990-12-25 | Sensormatic Electronics Corporation | Deactivatable E.A.S. marker having a step change in magnetic flux |
GB8818849D0 (en) * | 1988-08-09 | 1988-09-14 | Emi Plc Thorn | Electromagnetic identification system |
DE4007701A1 (en) * | 1990-03-10 | 1991-09-12 | Vacuumschmelze Gmbh | DISABLABLE THEFT PROTECTION STRIP |
US5083112A (en) * | 1990-06-01 | 1992-01-21 | Minnesota Mining And Manufacturing Company | Multi-layer thin-film eas marker |
US5313192A (en) * | 1992-07-02 | 1994-05-17 | Sensormatic Electronics Corp. | Deactivatable/reactivatable magnetic marker having a step change in magnetic flux |
-
1996
- 1996-02-09 DE DE19604746A patent/DE19604746A1/en not_active Withdrawn
-
1997
- 1997-01-15 DE DE59704093T patent/DE59704093D1/en not_active Expired - Lifetime
- 1997-01-15 ES ES97100501T patent/ES2160857T3/en not_active Expired - Lifetime
- 1997-01-15 EP EP97100501A patent/EP0789340B1/en not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0123586B1 (en) | 1983-03-25 | 1988-06-01 | FAIRCHILD CAMERA & INSTRUMENT CORPORATION | Tri-state driver circuit for automatic test equipment |
EP0153286A2 (en) * | 1984-02-15 | 1985-08-28 | Esselte Meto Eas International Ab | Method and system for detecting an indicating device |
US4660025A (en) | 1984-11-26 | 1987-04-21 | Sensormatic Electronics Corporation | Article surveillance magnetic marker having an hysteresis loop with large Barkhausen discontinuities |
EP0448114A1 (en) | 1990-03-23 | 1991-09-25 | Unitika Ltd. | Thin-film magnetic material and process of production thereof |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0901100A2 (en) * | 1997-08-27 | 1999-03-10 | Meto International GmbH | Magnetic identification element |
EP0901100A3 (en) * | 1997-08-27 | 2002-07-31 | Meto International GmbH | Magnetic identification element |
EP0949598A2 (en) * | 1998-04-08 | 1999-10-13 | Meto International GmbH | Electronic anti-theft element |
EP0949598A3 (en) * | 1998-04-08 | 2000-11-22 | Meto International GmbH | Electronic anti-theft element |
AU741785B2 (en) * | 1998-12-14 | 2001-12-06 | Meto International Gmbh | Security element for electronic article surveillance and method of manufacturing a security element |
WO2001078030A1 (en) * | 2000-04-07 | 2001-10-18 | Rso Corporation N.V. | A marker for remote detection of articles |
US7469838B2 (en) | 2001-12-10 | 2008-12-30 | Brewster Kaleidoscope Llc | Detectable components and detection apparatus for detecting such components |
Also Published As
Publication number | Publication date |
---|---|
EP0789340B1 (en) | 2001-07-25 |
DE59704093D1 (en) | 2001-08-30 |
ES2160857T3 (en) | 2001-11-16 |
DE19604746A1 (en) | 1997-08-14 |
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