EP0810567A1 - Device and method for securing an article against theft - Google Patents

Abstract

The device includes a strip of easily magnetised material (3.1) inserted between an article (1) and its film covering, which is a laminate in which the strip can be embedded. Alternative embodiments are a thin-film security tag and one incorporating a resonant oscillatory circuit. When an attempt is made to carry the article through an alternating magnetic field in a monitoring zone, a characteristic signal is emitted and an alarm is triggered. The resonant-circuit variant may comprise two capacitor plates separated by a dielectric layer and interconnected by a spiral flat conductor.

Description

The invention relates to a device and a method for electronically securing an article against theft.

Various security elements for electronically securing articles against theft have already become known. A particularly advantageous embodiment of a security element in the form of a "thin film" label is described in EP 0 295 028 B1. "Thin film" labels consist of a thin layer of soft magnetic material, preferably in the µm range. The soft magnetic layer is preferably applied to a carrier substrate by means of a physical deposition process under vacuum conditions.

In addition to the "thin film" labels, the so-called "strip" security elements, which consist of a strip-shaped, soft magnetic material or a soft magnetic wire, are used in particular for article security in the food sector.

Furthermore, resonance resonant circuits are used as security elements for article security. Such securing elements are described in detail, for example, in EP 285 559 B1. From EP 0 093 281 B1 Fuse elements have become known which are set into mechanical vibrations when a magnetic alternating field is applied and generate a detectable signal.

From EP 0 494 114 A2 so-called 'intelligent' transponders have become known which, in addition to securing the goods to which they are attached, also open up the possibility of clearly identifying the goods in question. The structure of a corresponding detection system is also described in this patent.

(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.A large number of different methods have become known for detecting security elements in an interrogation zone. EP 123 586 B proposes, in addition to two query fields with the frequencies f1 and f2 in the kHz range, to send a field with a frequency in the Hz range to the query zone. The two interrogation fields with the frequencies f1 and f2 excite a security element located in the interrogation zone for transmitting a characteristic signal with the intermodulation frequencies $\text{nf1 ± mf2}$

(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, it has also become known to use only a query field in the kHz range to excite the fuse element, the characteristic signal of the fuse element again occurring in the cycle of a low-frequency field, which drives the soft magnetic material back and forth between the two saturations .

A narrow-band alternating field is used to detect fuse elements with resonant resonant circuits radiated into the interrogation zone, which stimulates the security element to emit a characteristic signal in the region of its resonance frequency.

The invention is based on the object of proposing a device or a method which makes it considerably more difficult to remove a securing element from a secured article.

The object is achieved with regard to the device in that a protective film is provided which completely covers the securing element and the article at least in the area of the securing element.

According to advantageous developments of the device according to the invention, the securing element is a strip or a thin film made of a soft magnetic material or a resonant circuit which has the capacitance C, the resistance R and the inductance L or a magnetomechanical securing element which is provided by a magnetic Alternating field is excited to mechanical vibrations.

It has proven to be extremely advantageous to use a film (shrink film) that contracts when the temperature changes as a protective film. Such films are well known and are used inter alia. to protect an article against damage. They are also widely used where it is important to protect products from unauthorized opening. This ensures, in particular for packaging containing high-quality products, that the original product cannot be exchanged or mixed.

According to the invention, the protective films also have the additional function of connecting the securing element to the article to be secured and any manipulation of the securing element in a simple manner, but nevertheless extremely effective to prevent. By means of the device according to the invention, by means of a suitable placement of the securing element and a subsequent securing by means of the protective film, the secured and protected article is not opened before the purchase. This takes into account the high hygiene requirements when selling food, but especially when selling cosmetic products (cream jars, lipsticks, etc.). Furthermore, the fact that the securing element is fastened to the article by means of the protective film makes the unauthorized removal of the article considerably more difficult.

The embodiment in which the film is in the form of a tube which is pulled over the article and the securing element is to be regarded as particularly favorable. An alternative to the tubular protective film is a flat protective film which is wrapped around the article and the securing element. Either the film is heated after it has been applied to the article or it is wrapped around the article while it is still heated. When it cools, it shrinks and adapts optimally to the shape of the article to be protected.

It is particularly advantageous if the protective film is in the form of a laminate, the securing elements being embedded in the laminate and preferably being arranged in areas lying parallel to one another. By dividing the laminate, the size of the protective film can be easily matched to the size of the article to be secured.

With regard to the method, the object is achieved in that a protective film is connected to the article to be secured at least in the area of a securing element in such a way that it can only be detached from the article by destruction.

According to a first possibility, the securing element is connected to the article, e.g. laid on or glued on; the protective film is subsequently wrapped around the article or pulled onto the article, at least in the area of the securing element.

As an alternative embodiment of the method according to the invention, it is proposed to connect the securing element to the protective film; the protective film is then wrapped around the article or pulled onto the article so that the securing element is located between the article and the protective film. It is particularly advantageous here if the protective film with the integrated securing elements is produced as a laminate, the securing elements being arranged parallel to one another; the laminate is then cut to the required size depending on the article to be secured.

A third advantageous development of the method according to the invention proposes the securing element as an integral part of the protective film. This considerably facilitates the attachment of the securing element and the protective film to the article, since no separate parts have to be handled.

• Fig. 1: eine schematische Darstellung einer Ausführungsform der erfindungsgemäßen Vorrichtung,
• Fig. 2a: eine Draufsicht auf ein streifenförmiges Sicherungselement,
• Fig. 2b: eine Draufsicht auf ein "Thin Film"-Sicherungselement,
• Fig. 2c: eine Explosionsdarstellung eines Sicherungselementes mit einem Resonanzschwingkreis,
• Fig. 3a: eine Draufsicht auf eine Schutzfolie,
• Fig. 3b: eine perspektivische Ansicht einer schlauchförmigen Schutzfolie und
• Fig. 4: eine perspektivische Darstellung einer vorteilhaften Weiterbildung der erfindungsgemäßen Vorrichtung.

The invention is explained in more detail with reference to the following figures. It shows:

• 1: a schematic representation of an embodiment of the device according to the invention,
• 2a: a plan view of a strip-shaped securing element,
• 2b: a plan view of a "thin film" fuse element,
• 2c: an exploded view of a securing element with a resonant circuit,
• 3a: a top view of a protective film,
• 3b: a perspective view of a tubular protective film and
• 4 shows a perspective illustration of an advantageous development of the device according to the invention.

Fig. 1 shows a schematic representation of an embodiment of the device according to the invention. The securing element 3 - in the case shown is a strip 3.1 made of a soft magnetic material - is firmly fixed between the article 1 and the protective film 2.

The strip-shaped securing element 3.1 is shown separately in FIG. 2a. Figures 2b and 2c show a "thin film" label 3.2 and a label 3.3 with a resonant circuit. As can be seen from the exploded view of Fig. 2c, the fuse element 3.3 with resonant circuit consists of a spiral conductor element 4 (-> inductance L and resistor R) and a capacitor 4 (-> capacitance C), the two capacitor plates 4 through a dielectric layer 6 are spaced apart.

Fig. 3a shows a plan view of a flat piece of a protective film 2, which is wrapped around an article 1, so that the securing element 3 between article 1 and protective film 2 is fixed. A particularly favorable embodiment of the protective film 2 as a tube can be seen in FIG. 3b.

Fig. 4 shows a perspective view of an advantageous development of the device according to the invention. The protective film 2 with securing elements 3.1 here has the shape of a laminate 7. The securing elements 3.1 are arranged in areas lying parallel to one another. Depending on the size of the article to be secured, the laminate 7 is divided into areas B of different sizes.

Reference list

1

items

2nd

Protective film

3.1

strip-shaped securing element

3.2

"Thin film" security element

3.3

Securing element with resonant circuit

4th

spiral conductor element

5

Capacitor plate

6

dielectric layer

7

Laminate

B

Area

C.

capacity

L

Inductance

R

resistance

Claims (13)

Device for electronic article monitoring, consisting of a security element, which is connected to an article to be secured and is excited by a magnetic alternating field generated within an interrogation zone to emit a characteristic signal, which triggers an alarm,
characterized,
that a protective film (2) is provided which completely covers the securing element (3) and the article (1) at least in the area of the securing element (3). Device according to claim 1,
characterized,
that the securing element (3) is a strip-shaped element (3.1) made of a soft magnetic material. Device according to claim 1,
characterized,
that the securing element (3) is a thin film (3.2) made of a soft magnetic material. Device according to claim 1,
characterized,
that the fuse element (3) is a resonant circuit (3.3) which has a capacitance C, a resistor R and an inductance L. Device according to claim 1, 2, 3 or 4,
characterized,
that the protective film (2) is a film that contracts when the temperature changes (shrink film). Device according to claim 5,
characterized,
that the protective film (2) has the shape of a tube which is pulled over the article (1) with the securing element (3). Device according to claim 5,
characterized,
that the protective film (2) is a flat structure which is wound around the article (1) including the securing element (3). Device according to claim 7,
characterized,
that the protective film (2) is in the form of a laminate (7), the securing elements (3) being embedded in the laminate (7) and preferably being arranged in areas lying parallel to one another. Method for electronic article security, wherein a security element is used, which is connected to an article to be secured and is stimulated to emit a characteristic signal by an alternating magnetic field generated within an interrogation zone, thereby triggering an alarm,
characterized,
that a protective film (2) is connected at least in the area of a securing element (3) to the article (1) to be secured in such a way that it can only be detached from the article (1) by destruction. Method according to claim 9,
characterized,
that the securing element (3) is connected to the article (1) and that subsequently the protective film (2) is wound or pulled onto the article (1) at least in the area of the securing element (3). Method according to claim 9,
characterized,
that the securing element (3) is connected to the protective film (2) and that the protective film (2) is subsequently wound or pulled onto the article (1) so that the securing element (3) is located between the article (1) and the protective film (2 ) is located. A method according to claim 11,
characterized,
that the securing element (3) is manufactured as an integral part of the protective film (2). Method according to claim 12,
characterized,
that the protective film (2) is produced as a laminate (7), the securing elements (3) being arranged parallel to one another, and that the laminate (7) is cut to the required size depending on the article (1) to be secured.

Images