EP0388609A2 - Electronic antipilferage device and method for the operation of such a device - Google Patents

Electronic antipilferage device and method for the operation of such a device Download PDF

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Publication number
EP0388609A2
EP0388609A2 EP90102051A EP90102051A EP0388609A2 EP 0388609 A2 EP0388609 A2 EP 0388609A2 EP 90102051 A EP90102051 A EP 90102051A EP 90102051 A EP90102051 A EP 90102051A EP 0388609 A2 EP0388609 A2 EP 0388609A2
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EP
European Patent Office
Prior art keywords
transmitter
receiver
signals
resonance
frequency
Prior art date
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.)
Granted
Application number
EP90102051A
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German (de)
French (fr)
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EP0388609B1 (en
EP0388609A3 (en
Inventor
Markus Martinides
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Actron Entwicklungs AG
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Actron Entwicklungs AG
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Classifications

    • 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
    • G08B13/2414—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 inductive tags
    • 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
    • G08B13/2465—Aspects related to the EAS system, e.g. system components other than tags
    • G08B13/2468—Antenna in system and the related signal processing
    • G08B13/2471—Antenna signal processing by receiver or emitter
    • 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
    • G08B13/2465—Aspects related to the EAS system, e.g. system components other than tags
    • G08B13/2488—Timing issues, e.g. synchronising measures to avoid signal collision, with multiple emitters or a single emitter and receiver

Definitions

  • the present invention relates to an electronic anti-theft device with a transmitter that generates an electromagnetic field that excites the resonance circuit on a resonance tag, which may be located in the reception area of the transmitter, and a receiver that responds to the signals of the transmitter and one, if applicable, in the reception area addressed resonance tag, evaluates these signals and triggers an alarm signal when a signal of the resonance tag is detected and a method for operating such a device.
  • the object of the present invention is now to provide a device of the type defined at the outset, which is able to eliminate the interfering influences without complex and often ineffective filter device.
  • the invention makes use of the fact that when the transmitter or transmitters are switched off, on the one hand, the emitted signals (electromagnetic field) and the interferences caused by them are practically immediate, i.e. practically without delay, e.g. disappear after 1/2 ⁇ sec. (within one oscillation period), on the other hand the signal caused by the resonance label decays only relatively slowly, since the vibrational energy stored in the resonance label of the labels acting as transmitter is only slowly reduced (up to 5 ⁇ sec. , or 20-30 oscillation periods of the resonance frequency).
  • the transmitter emits an electromagnetic pulse periodically for a short period of time, the spectrum of which (broadband) covers the resonance frequency of the label and which is sufficiently energetic to excite the resonance circuit of the resonance label
  • This echo method is particularly effective because the receiver can be set to a very high sensitivity in the transmission pause due to the complete absence of the transmission signal (no "idle signal").
  • a pulse with only one frequency can be used instead of a broadband transmission pulse, in which case this frequency is changed in a manner known per se by a small amount for each further pulse compared to the frequency of the previous pulse.
  • the transmitter can be swept in steps and the resonance label is also recorded in this case if the frequency steps are sufficiently small and the entirety of the “discrete” transmission frequencies defined in this way covers the resonance frequency of the label.
  • the receiver can then also be designed to be very narrow-band, the reception frequency being automatically matched to the transmission frequency and carried with it.
  • the narrowband receiver offers the additional advantage of high interference suppression and low noise.
  • the narrow-band transmitter arises in such multiple systems if the individual transmitters are swept through with a frequency offset, ie all transmitters transmit at the same time and for the same period of time, but each transmitter on a frequency which is different from the frequency of any other transmitter, however, in such a way that each transmitter also transmits once on each of the defined "discrete" wobble frequencies during a wobble cycle.
  • a transmitter jumps, which transmits at the maximum wobble frequency, with the subsequent transmission pulse back to the minimum transmission frequency.
  • each transmitter-receiver device Since the superposition principle of the electromagnetic fields applies because of the linear behavior of the label, and since each transmitter transmits at a frequency that is different from the frequency of every other transmitter, and since each receiver only receives at the respective frequency of its assigned transmitter, so see none of the receivers has an effect that comes from a transmitter other than the transmitter assigned to it, ie each individual transmitter-receiver device also functions in the presence of all other installations of the overall system as if it were installed as a single system, ie as if all the others Installations would be switched off. If a transmitter-receiver pair is optimally set in single operation, it remains optimal even during the simultaneous operation of all transmitter-receiver pairs in the entire system.
  • the individual transmitter-receiver pairs are synchronized by signals that are transmitted to them wirelessly from a central office or that they transmit directly to one another (e.g. via their transmitters and receivers, which are intended for resonance label detection).
  • the transmitter antenna and the receiver antenna are at the same location, e.g. can be accommodated in the same frame. It is also readily possible to use the same (single) antenna for the transmitter and the receiver, since any alarm-triggering signals only have to be received or evaluated during the pauses in transmission. This may simplify essential the installation of monitoring devices.

Abstract

The antipilferage or surveillance device with a transmitter and a receiver for signals of a resonance label located where appropriate in the receiver range is designed so that the transmitter transmits or does not transmit periodically during alternating time phases only, and the receiver evaluates only the signals received where appropriate during the relevant transmission pauses in order to activate an alarm.

Description

Die vorliegende Erfindung betrifft eine elektro­nische Diebstahlsicherungseinrichtung mit einem Sender, welcher ein elektromagnetisches Feld erzeugt, welches die Resonanzschaltung auf einer Resonanzetikette, welche sich gegebenenfalls im Empfangsbereich des Senders be­findet, anregt und einem Empfänger, welcher auf die Signale des Senders und einer sich gegebenenfalls im Empfangsbereich befindlichen Resonanzetikette anspricht, diese Signale auswertet und bei Feststellen eines Signals der Resonanzetikette ein Alarmsignal auslöst sowie ein Verfahren zum Betrieb einer solchen Einrichtung.The present invention relates to an electronic anti-theft device with a transmitter that generates an electromagnetic field that excites the resonance circuit on a resonance tag, which may be located in the reception area of the transmitter, and a receiver that responds to the signals of the transmitter and one, if applicable, in the reception area addressed resonance tag, evaluates these signals and triggers an alarm signal when a signal of the resonance tag is detected and a method for operating such a device.

Einrichtungen dieser Art sind heute weitherum bekannt und in Verkaufsläden, insbesondere in Warenhäusern in Betrieb. Der grundsätzliche Aufbau sowohl der mit Sender und Empfänger ausgerüsteten Einrichtung wie auch der Resonanzschaltung auf den sog. Resonanzetiketten ist bekannt und bedarf keiner weiteren Erläuterung. Eine solche Einrichtung ist z.B. in der DE-PS 22 63 905 beschrieben.Facilities of this type are widely known today and in operation in shops, especially in department stores. The basic structure of both the device equipped with transmitter and receiver and the resonance circuit on the so-called resonance labels is known and requires no further explanation. Such a device is e.g. described in DE-PS 22 63 905.

Die bekannten Einrichtungen weisen jedoch gewisse Nachteile auf, welche auf nachstehenden Störfaktoren beruhen:However, the known devices have certain disadvantages which are based on the following disruptive factors:

Beim Durchwobbeln über einen Frequenzbereich, innerhalb dessen die Resonanzfrequenz der sich im Sender-­Empfangsfrequenzbereich befindlichen Resonanzetikette liegt, entsteht eine charakteristische Verformung des Empfangssignals, welche ausgewertet wird und zur Auslösung des Alarms führt. Da sich aber auch Störsignale von verschiedenen Quellen dem Empfangssignal überlagern, und die Charakteristik der durch die Etikette hervorge­rufene Verformung in weiten Grenzen schwankt, ist es sehr schwer, eine genügende Diskriminierung des Etiketten­signals (= Nutzsignal ) von den Störsignalen zu erreichen.When sweeping over a frequency range within which the resonance frequency of the resonance label located in the transmitter reception frequency range lies, a characteristic deformation of the arises Receive signal, which is evaluated and leads to the triggering of the alarm. However, since interference signals from different sources are superimposed on the received signal, and the characteristic of the deformation caused by the label fluctuates within wide limits, it is very difficult to adequately discriminate the label signal (= useful signal) from the interference signals.

Die ausgeprägtesten und trotz Filterung nicht zu vermeidenden Störsignale werden durch Interferenz hervorgerufen:The most pronounced interference signals that cannot be avoided despite filtering are caused by interference:

Bei einer Einzelanlage entstehen Reflexionen und Beugungen des eigenen Sendersignals, die miteinander und dem ursprünglichen Sendersignal interferieren.In a single system, reflections and diffractions of the own transmitter signal arise, which interfere with each other and the original transmitter signal.

Zusätzlich zu dieser Interferenz bilden sich bei Mehrfachanlagen ähnliche Interferenzen durch Ueber­lagerung der Signale von benachbarten Sendern (und deren Reflexionen).In addition to this interference, similar interference is formed in multiple systems by superimposing the signals from neighboring transmitters (and their reflections).

Da diese Interferenzen wegen der Phasenunterschiede der sich überlagernden Signale abhängig sind von der momentanen Senderfrequenz (bei Mehrfachanlagen sind die Sender zwar in der Regel synchronisiert, d.h. sie senden in jedem Zeitpunkt auf derselben Frequenz), ist auch das Empfangssignal für jede Frequenz verschieden, dies auch bei Abwesenheit irgendeines Resonators. Beim Durchwobbeln des Senders entsteht somit ein Empangssignal, das sich deutlich von einem konstanten (und nur theoretisch vorhandenen) "Ruhesignal" unterscheidet und oft einem Etikettensignal zum Verwechseln ähnlich sieht.Since these interferences are dependent on the phase differences of the overlapping signals on the current transmitter frequency (in the case of multiple systems, the transmitters are generally synchronized, i.e. they transmit on the same frequency at all times), the received signal is different for each frequency, too in the absence of any resonator. When the transmitter is swept through, an reception signal is produced which differs significantly from a constant (and only theoretically available) "idle signal" and often looks confusingly similar to a label signal.

Aufgabe der vorliegenden Erfindung ist es nun, eine Einrichtung der eingangs definierten Art zu schaffen, welche die störenden Einflüsse ohne aufwendige und oft wenig wirksame Filtereinrichtung auszuschalten vermag.The object of the present invention is now to provide a device of the type defined at the outset, which is able to eliminate the interfering influences without complex and often ineffective filter device.

Diese Aufgabe wird bei einer Einrichtung der genannten Art erfindungsgemäss durch die im Kennzeichen der Ansprüche 1 und 11 aufgeführten Merkmale gelöst.This object is achieved according to the invention in a device of the type mentioned by the features listed in the characterizing part of claims 1 and 11.

Die vorzugsweise Ausführung der einzelnen Bestand­teile der Einrichtung ergibt sich aus den abhängigen Patentansprüchen.The preferred design of the individual components of the device results from the dependent claims.

Die Erfindung wird nachstehend noch etwas näher erläutert:The invention is explained in more detail below:

Die Erfindung macht Gebrauch davon, dass beim Ausschalten des bzw. der Sender einerseits die ausgesen­deten Signale (elektromagnetisches Feld) und die durch diese verursachten Interferenzen praktisch sofort, d.h. praktisch verzögerungsfrei, z.B. nach 1/2 µ Sek. (innerhalb einer Schwingungsperiode) verschwinden, andererseits das durch die Resonanzetikette verursachte Signal aber nur relativ langsam abklingt, da die in der Resonanzeti­kette gespeicherte Schwingungsenergie der als Sender wirkenden Etikette nur langsam abgebaut wird (bis zu 5 µ Sek., bzw. 20-30 Schwingungsperioden der Resonanzfre­quenz).The invention makes use of the fact that when the transmitter or transmitters are switched off, on the one hand, the emitted signals (electromagnetic field) and the interferences caused by them are practically immediate, i.e. practically without delay, e.g. disappear after 1/2 µsec. (within one oscillation period), on the other hand the signal caused by the resonance label decays only relatively slowly, since the vibrational energy stored in the resonance label of the labels acting as transmitter is only slowly reduced (up to 5 µsec. , or 20-30 oscillation periods of the resonance frequency).

Betreibt man also eine Einzelanlage in der Art, dass der Sender periodisch jeweils während einer kurzen Zeitspanne einen elektromagnetischen Puls abgibt, dessen Spektrum (breitbandig) die Resonanzfrequenz der Etikette überdeckt und der genügend energiereich ist, um den Resonanzschaltkreis der Resonanzetikette anzuregen, so kann man in der anschliessenden Pause die Etikette mit Hilfe des Empfängers an der elektromagnetischen Strahlung erkennen, die sie auf ihrer Resonanzfrequenz aussendet. Dieses Echoverfahren ist deshalb besonders wirkungsvoll, weil in der Sendepause wegen der völligen Abwesenheit des Sendesignals (kein "Ruhesignal") der Empfänger auf sehr hohe Empfindlichkeit gestellt werden kann.If you operate a single system in such a way that the transmitter emits an electromagnetic pulse periodically for a short period of time, the spectrum of which (broadband) covers the resonance frequency of the label and which is sufficiently energetic to excite the resonance circuit of the resonance label, you can in In the subsequent pause, use the receiver to recognize the label from the electromagnetic radiation that it emits at its resonance frequency. This echo method is particularly effective because the receiver can be set to a very high sensitivity in the transmission pause due to the complete absence of the transmission signal (no "idle signal").

Alternativ kann man anstelle eines breitbandigen Sendepulses einen Puls mit nur einer Frequenz verwenden, wobei dann diese Frequenz in an sich bekannter Weise bei jedem weiteren Puls um einen kleinen Betrag verändert wird gegenüber der Frequenz des vorhergehenden Pulses. Auf diese Art lässt sich der Sender in Schritten durchwob­beln und die Resonanzetikette wird auch in diesem Fall erfasst, falls die Frequenzschritte ausreichend klein sind und die Gesamtheit der so definierten "diskreten" Sendefrequenzen die Resonanzfrequenz der Etikette über­deckt. Bei diesem Verfahren kann dann auch der Empfänger sehr schmalbandig ausgelegt sein, wobei die Empfangs­frequenz automatisch auf die Sendefrequenz abgestimmt und mit ihr mitgeführt wird. Der schmalbandige Empfänger bietet den zusätzlichen Vorteil hoher Störunterdrückung und geringen Rauschens.Alternatively, a pulse with only one frequency can be used instead of a broadband transmission pulse, in which case this frequency is changed in a manner known per se by a small amount for each further pulse compared to the frequency of the previous pulse. In this way, the transmitter can be swept in steps and the resonance label is also recorded in this case if the frequency steps are sufficiently small and the entirety of the “discrete” transmission frequencies defined in this way covers the resonance frequency of the label. In this method, the receiver can then also be designed to be very narrow-band, the reception frequency being automatically matched to the transmission frequency and carried with it. The narrowband receiver offers the additional advantage of high interference suppression and low noise.

Selbstverständlich ist es auch möglich, eine Anlage vorzusehen, bei welcher eine Vielzahl Sender-Empfän­ger-Paare aufgestellt werden. Bei diesen werden dann wie beim Einzelpaar die Sender periodisch ein- bzw. ausgeschaltet (bei allen Sendern gleichzeitig bzw. synchron).Of course, it is also possible to provide a system in which a large number of transmitter-receiver pairs are set up. With these, the transmitters are then switched on or off periodically, as with the individual pair (for all transmitters simultaneously or synchronously).

Ein weiterer Vorteil des schmalbandigen Senders ergibt sich bei solchen Mehrfachanlagen, falls die einzel­nen Sender frequenzversetzt durchgewobbelt werden, d.h. alle Sender zum selben Zeitpunkt senden und während der gleichen Zeitdauer, aber jeder Sender auf einer Frequenz, die verschieden ist von der Frequenz jedes anderen Senders, jedoch so, dass jeder Sender während eines Wobbelzyklus auch auf jeder der festgelegten "diskre­ten" Wobbelfrequenzen einmal sendet. Hierbei springt ein Sender, der auf der maximalen Wobbelfrequenz sendet, beim anschliessenden Sendepuls auf die minimale Sende­frequenz zurück. Da wegen des linearen Verhaltens der Etikette das Superpositionsprinzip der elektromagnetischen Felder gilt, und da jeder Sender auf einer Frequenz sendet, die verschieden ist von der Frequenz jedes anderen Senders, und da jeder Empfänger nur auf der jeweiligen Frequenz seines ihm zugeordneten Senders empfängt, so sieht keiner der Empfänger einen Effekt, der von einem anderen Sender herrührt als dem ihm zugeordneten Sender, d.h. jede einzelne Sender-Empfänger-Einrichtung funk­tioniert auch in Anwesenheit aller übrigen Installationen der Gesamtanlage so, wie wenn sie als Einzelanlage instal­liert wäre, d.h. wie wenn alle übrigen Installationen abgeschaltet wären. Ist also ein Sender-Empfänger-Paar optimal eingestellt im Einzelbetrieb, so bleibt es optimal auch während des gleichzeitigen Betriebs aller Sender-­Empfänger-Paare der gesamten Anlage.Another advantage of the narrow-band transmitter arises in such multiple systems if the individual transmitters are swept through with a frequency offset, ie all transmitters transmit at the same time and for the same period of time, but each transmitter on a frequency which is different from the frequency of any other transmitter, however, in such a way that each transmitter also transmits once on each of the defined "discrete" wobble frequencies during a wobble cycle. Here a transmitter jumps, which transmits at the maximum wobble frequency, with the subsequent transmission pulse back to the minimum transmission frequency. Since the superposition principle of the electromagnetic fields applies because of the linear behavior of the label, and since each transmitter transmits at a frequency that is different from the frequency of every other transmitter, and since each receiver only receives at the respective frequency of its assigned transmitter, so see none of the receivers has an effect that comes from a transmitter other than the transmitter assigned to it, ie each individual transmitter-receiver device also functions in the presence of all other installations of the overall system as if it were installed as a single system, ie as if all the others Installations would be switched off. If a transmitter-receiver pair is optimally set in single operation, it remains optimal even during the simultaneous operation of all transmitter-receiver pairs in the entire system.

Bei solchen Anlagen werden die einzelnen Sender­Empfänger-Paare durch Signale synchronisiert, die ihnen drahtlos von einer Zentrale aus übermittelt werden oder die sie einander direkt übermitteln (z.B. über ihre Sender und Empfänger, die zur Resonanzetikettenerkennung vorgesehen sind).In such systems, the individual transmitter-receiver pairs are synchronized by signals that are transmitted to them wirelessly from a central office or that they transmit directly to one another (e.g. via their transmitters and receivers, which are intended for resonance label detection).

Ein weiterer Vorteil des erfindungsgemässen Prinzips liegt darin, dass die Sender-Antenne und die Empfänger-Antenne am gleichen Ort, z.B. im gleichen Rahmen, untergebracht werden können. Es ist auch ohne weiteres möglich, dass für den Sender und den Empfänger dieselbe (einzige) Antenne verwendet wird, da eventuelle alarmauslösende Signale nur während der Sendepausen empfangen bzw. ausgewertet werden müssen. Dies vereinfacht u.U. wesentlich die Installation von Ueberwachungsein­richtungen.Another advantage of the principle according to the invention is that the transmitter antenna and the receiver antenna are at the same location, e.g. can be accommodated in the same frame. It is also readily possible to use the same (single) antenna for the transmitter and the receiver, since any alarm-triggering signals only have to be received or evaluated during the pauses in transmission. This may simplify essential the installation of monitoring devices.

Claims (11)

1. Elektronische Diebstahlsicherungseinrichtung, mit einem Sender, welcher ein elektromagnetisches Feld erzeugt, welches die Resonanzschaltung auf einer Resonanz­etikette, welche sich gegebenenfalls im Empfangsbereich des Senders befindet, anregt und einem Empfänger, welcher auf die Signale des Senders und einer sich gegebenenfalls im Empfangsbereich befindlichen Resonanzetikette anspricht, diese Signale auswertet und bei Feststellen eines Signals der Resonanzetikette ein Alarmsignal auslöst, dadurch gekennzeichnet, dass Mittel vorgesehen sind, um den Sender während einander abwechselnder Zeitphasen in Betrieb zu halten, resp. auszuschalten, und dass der Empfänger mit Mitteln ausgerüstet ist, welche bewirken, dass lediglich die während der Sendepausen gegebenenfalls empfangenen Signale zur Auslösung eines Alarmsignals ausgewertet werden.1. Electronic anti-theft device, with a transmitter that generates an electromagnetic field, which excites the resonance circuit on a resonance label, which may be located in the reception area of the transmitter, and a receiver, which detects the signals of the transmitter and a resonance label, which may be in the reception area responds, evaluates these signals and triggers an alarm signal when a signal of the resonance tag is detected, characterized in that means are provided to keep the transmitter in operation during alternating time phases, respectively. to switch off, and that the receiver is equipped with means which ensure that only the signals possibly received during the transmission pauses are evaluated to trigger an alarm signal. 2. Einrichtung nach Anspruch 1, dadurch gekenn­zeichnet, dass der Sender ein Signal mit bezüglich Breite und Lage vorbestimmtem Frequenzband aussendet.2. Device according to claim 1, characterized in that the transmitter emits a signal with a predetermined frequency band with respect to width and position. 3. Einrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass der Sender zu verschiedenen Zeitpunk­ten einer Periode jeweils mit verschiedenen schmalbandigen Frequenzen sendet.3. Device according to claim 1 or 2, characterized in that the transmitter transmits at different times of a period each with different narrow-band frequencies. 4. Einrichtung nach einem der Ansprüche 1-3, dadurch gekennzeichnet, dass der Empfänger schmalbandig auf der Frequenz des Senders empfängt.4. Device according to one of claims 1-3, characterized in that the receiver receives narrowband on the frequency of the transmitter. 5. Elektronische Diebstahlsicherungseinrichtung mit einer Mehrzahl von Sender-Empfänger-Paaren nach Anspruch 1-4, dadurch gekennzeichnet, dass jeder Sender eines Paares auf einer Frequenz sendet, die verschieden ist von der Frequenz des Senders jedes anderen Paares, wobei alle Sender gleichzeitig in Betrieb stehen, bzw. ausgeschaltet sind.5. Electronic anti-theft device with a plurality of transmitter-receiver pairs according to claim 1-4, characterized in that each transmitter of a pair transmits at a frequency which is different from the frequency of the transmitter of each other pair, with all transmitters operating simultaneously stand or are switched off. 6. Einrichtung nach Anspruch 5, dadurch gekennzeich­net, dass die einzelnen Paare der Anlage durch Signale synchronisiert werden, die drahtlos von einer Zentrale aus an die Paare übermittelt werden.6. Device according to claim 5, characterized in that the individual pairs of the system are synchronized by signals which are transmitted wirelessly from a center to the pairs. 7. Einrichtung nach Anspruch 5, dadurch gekenn­zeichnet, dass die einzelnen Paare der Anlage durch Signale synchronisiert werden, die sie einander drahtlos übermitteln.7. Device according to claim 5, characterized in that the individual pairs of the system are synchronized by signals which they transmit to each other wirelessly. 8. Einrichtung nach Anspruch 6 oder 7, dadurch gekennzeichnet, dass die einzelnen Paare der Anlage durch Signale synchronisiert werden, die sie einander über ihre zur Resonanzetiketten-Erkennung vorgesehenen Sender und Empfänger übermitteln.8. Device according to claim 6 or 7, characterized in that the individual pairs of the system are synchronized by signals which they transmit to one another via their transmitter and receiver provided for resonance label detection. 9. Einrichtung nach einem der Ansprüche 1-8, dadurch gekennzeichnet, dass die Sender-Antenne und die Empfänger-Antenne jedes Sender-Empfänger-Paares am gleichen Ort, z.B. im gleichen Rahmen, angebracht sind.Device according to one of claims 1-8, characterized in that the transmitter antenna and the receiver antenna of each transmitter-receiver pair at the same location, e.g. in the same frame. 10. Einrichtung nach Anspruch 9, dadurch gekenn­zeichnet, dass für den Sender und den Empfänger jedes Paares nur jeweils eine einzige gemeinsame Antenne vor­gesehen ist.10. Device according to claim 9, characterized in that only a single common antenna is provided for the transmitter and the receiver of each pair. 11. Verfahren zum Betrieb einer elektronischen Diebstahlsicherungseinrichtung mit einem Sender, welcher ein elektromagnetisches Feld erzeugt, welches die Resonanz­schaltung auf einer Resonanzetikette, welche sich gegebe­nenfalls im Empfangsbereich des Senders befindet, anregt und einem Empfänger, welcher auf die Signale des Senders und einer sich gegebenenfalls im Empfangsbereich befindli­chen Resonanzetikette anspricht, diese Signale auswertet und bei Feststellen eines Signals der Resonanzetikette ein Alarmsignal auslöst, dadurch gekennzeichnet, dass der Sender während einander abwechselnden Zeitphasen in Betrieb gehalten, resp. ausgeschaltet wird, und dass der Empfänger lediglich die während der Sendepausen gegebenenfalls empfangenen Signale zur Auslösung eines Alarmsignals auswertet.11. Method for operating an electronic anti-theft device with a transmitter that generates an electromagnetic field that excites the resonance circuit on a resonance tag, which may be located in the reception area of the transmitter, and a receiver that responds to the signals of the transmitter and one that may be in the Addresses the resonance label located, evaluates these signals and triggers an alarm signal when a signal of the resonance label is detected, characterized in that the transmitter is kept in operation during alternating time phases, respectively. is switched off, and that the receiver only evaluates the signals possibly received during the transmission breaks to trigger an alarm signal.
EP19900102051 1989-03-22 1990-02-02 Electronic antipilferage device Expired - Lifetime EP0388609B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH107889A CH681051A5 (en) 1989-03-22 1989-03-22
CH1078/89 1989-03-22

Publications (3)

Publication Number Publication Date
EP0388609A2 true EP0388609A2 (en) 1990-09-26
EP0388609A3 EP0388609A3 (en) 1991-03-20
EP0388609B1 EP0388609B1 (en) 1997-12-29

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ID=4201949

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19900102051 Expired - Lifetime EP0388609B1 (en) 1989-03-22 1990-02-02 Electronic antipilferage device

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EP (1) EP0388609B1 (en)
JP (1) JPH02284294A (en)
CH (1) CH681051A5 (en)
DE (1) DE59010785D1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3740742A (en) * 1971-05-11 1973-06-19 T Thompson Method and apparatus for actuating an electric circuit
US4215342A (en) * 1978-03-31 1980-07-29 Intex Inc. Merchandise tagging technique
FR2515362A1 (en) * 1981-10-23 1983-04-29 Knogo Corp METHOD AND APPARATUS FOR DETECTING THE FLIGHT BY DETECTING THE ATTENUATION OF A RESONANT CIRCUIT
EP0131440A1 (en) * 1983-07-05 1985-01-16 Minnesota Mining And Manufacturing Company Variable frequency RF electronic surveillance system
EP0226402A2 (en) * 1985-12-06 1987-06-24 Minnesota Mining And Manufacturing Company Wireless synchronization system for electronic article surveillance system
US4686517A (en) * 1982-07-21 1987-08-11 N.V. Nederlandsche Apparatenfabriek Nedap Field disturbance detection system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3740742A (en) * 1971-05-11 1973-06-19 T Thompson Method and apparatus for actuating an electric circuit
US4215342A (en) * 1978-03-31 1980-07-29 Intex Inc. Merchandise tagging technique
FR2515362A1 (en) * 1981-10-23 1983-04-29 Knogo Corp METHOD AND APPARATUS FOR DETECTING THE FLIGHT BY DETECTING THE ATTENUATION OF A RESONANT CIRCUIT
US4686517A (en) * 1982-07-21 1987-08-11 N.V. Nederlandsche Apparatenfabriek Nedap Field disturbance detection system
EP0131440A1 (en) * 1983-07-05 1985-01-16 Minnesota Mining And Manufacturing Company Variable frequency RF electronic surveillance system
EP0226402A2 (en) * 1985-12-06 1987-06-24 Minnesota Mining And Manufacturing Company Wireless synchronization system for electronic article surveillance system

Also Published As

Publication number Publication date
EP0388609B1 (en) 1997-12-29
EP0388609A3 (en) 1991-03-20
CH681051A5 (en) 1992-12-31
DE59010785D1 (en) 1998-02-05
JPH02284294A (en) 1990-11-21

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