SEALING DEVICE

Abstract: The present invention relates to a sealing device provided for being applied onto an object to be sealed, said device comprising an electronic component with a memory, which component is connected to a detection loop provided for letting energy circulating through it and to be broken upon breaking said sealing device, said component being further connected to communication means for communicating with reading means, characterised in that said communication means comprise a communication loop provided for receiving power for powering up said sealing device.

Description: "Sealing device" The present invention relates to a sealing device provided for being applied onto an object to be sealed, said device comprising an electronic component with a memory, which component is connected to a detection loop provided for letting energy circulating through it and to be broken upon breaking said sealing device, said component being further connected to communication means for communicating with reading means. Such a device is known from patent application PCT/US90/0008 . In this device, the communication means is provided in the form of a transmitter or a transmitter/receiver connected to a bus in a control box. The control box is further provided with electronic components and an own power supply, e.g. an alkaline battery, in order to supply energy to the electronic components for recording when the detection loop has been violated and also in order to enable transmission from the communication means towards a central watch station. A drawback of the known device is that is requires necessarily the presence of an own power supply in order to furnish energy to the electronic components and in order to enable transmission from the communication means towards the central watch station. It is an object of the present invention to provide a sealing device which does not require necessarily the presence of an own power supply in order to be operable. To this object, the sealing device according to the invention is characterised in that said communication means comprise a communication loop provided for receiving power for powering up said sealing device. The communication means in the form of a communication loop enables to form a simple and compact sealing device. Since the communication means are provided for receiving power for powering up said sealing device, the sealing device according to the invention may be powered up by an external power supply and consequently does not require necessarily an own power supply. According to a first preferred embodiment, the sealing device according to the invention said communication loop is provided for receiving power from said reading means. This enables to form a sealing device which is only activated when communicating with the reading means. According to a second preferred embodiment of the device according to the invention, said detection loop is connected in parallel with the communication loop. This enables to have an electronic component which is only provided with two connection ports instead of four, for connecting the communication loop and the detection loop, without affecting the presence of two loops. According to a third preferred embodiment of the device according to the invention, a capacitance or an inductance is provided in the detection loop. This enables to detect a difference of resonance frequency of the energy circulating through the first and the detection loop. In case the object has been opened, the detection loop will be broken so that energy will circulate only through the communication loop, which gives another resonance frequency than in the case the detection loop is intact. According to a fourth preferred embodiment, the device according to the invention comprises means provided for generating a first codeword upon establishing that the detection loop is intact and a second codeword upon establishing that the detection loop is broken. This forms an alternative to detect whether or not the sealing device has been broken. According to a fifth preferred embodiment of the device according to the invention, said memory is connected to counter means provided for memorising how many times the object, onto which the device has been applied, has been sealed. This enables to use the same sealing device to objects, which have to be opened several times at determined places during the travel between the originating place and the destination place, e.g. a container which has to be checked several times, such as for example several customs. According to a sixth preferred embodiment of the device according to the invention, a first identification codeword for identifying said device is stored in said memory. This enables to readily identify the device, which is useful in case a plurality of sealing devices, each having their own first identification codeword, have to be checked with the reading means. Referring to the annexed figures, the device according to the invention will now be described into details, whereby same reference numerals refer to a same component. Figure 1 is a schematic view of the sealing device according to a first preferred embodiment. Figure 2 is a schematic view of the sealing device according to a second preferred embodiment. Figure 3 is a schematic view of the sealing device according to a third preferred embodiment. Figure 4 is a detail of the electronic component of the sealing device. Figure 5 is a detail of the electronic component of the sealing device according to an alternative. The sealing device 1 according to the invention, illustrated in the figures, is provided to be applied on an object to be sealed, such a for example a container or a valuable product. It comprises an electronic component 2, e.g. a microchip, provided with a memory 8 (Figures 4 and 5). The electronic component is connected to a communication loop 3 comprising a communication means, for example a coil 4. The coil 4 is provided for communicating with reading means (not illustrated). According to the invention, a detection loop 5 is connected to the electronic component 2, either directly or in parallel with the communication loop 3, and is provided for letting energy circulating through it and to break (illustrated by the dotted lines) upon breaking the sealing device. The advantage of having the detection loop 5 connected in parallel with the communication loop 3 is that only two in/outputs must be provided on the electronic component. The detection loop is a galvanic conductive loop which preferably consists of a very thin wire having for example a section diameter of 30 μm. Such a thin wire prevents the detection loop from being easily fraudulently fixed once it has been broken. The sealing device according to the invention is passive, i.e. powered by an external source, in particular the reading means, so that a very compact device can be made which is not dependent from the power of an own source, such as e.g. a battery, which would otherwise be provided in the sealing device. Turning now to Figures 1 and 2, a first, respectively a second embodiment, are illustrated. The detection loop comprises further a capacitance 6 (Figure 1 ) or an inductance 7 (Figure 2). To check if the sealing device according to Figures 1 and 2 is open, use is made of the resonance frequency technique. According to this technique, the reading means, which comprises another communication means such as a coil, is coupled, e.g. inductively to the coil 4 and supplies energy, e.g. current, through the intermediary of the communication coil 4 to the communication loop 3 and the detection loop 5. If the object has been opened, the detection loop will be broken, as illustrated by the dotted lines, so that no energy passes through the capacitance 6 or the inductance 7. If the detection loop 5 is still intact, a portion of the supplied energy will pass through this parallelly connected detection loop 5. In this case, a parallel LC (Figure 1 ) or LL (Figure 2) circuit is formed by the communication coil 4 of the communication loop 3 and the capacitance (Figure 1 ) or inductance (Figure 2) of the detection loop 5. Consequently, the energy returned to the reading means will resonate at a different frequency than in the case the detection loop 5 is broken whereby no energy will circulate through the detection loop 5. Figure 3 illustrates a third preferred embodiment of the sealing device according to the invention. According to this embodiment, the electronic component comprises a logic component 9 connected to the memory 8 (Figures 4 and 5). The logic component could for example be a D-flip-flop, whereby the first extremity 10 of the detection loop 5 is connected to the clock input of the flip-flop and the second extremity 11 of the detection loop 5 to the D-input of the flip-flop. Upon powering up the sealing device, energy is supplied to the first extremity 10 of the detection loop 5. If the detection loop is intact, the energy will arrive at the second extremity 11. This means that both the D-input and the clock input have the value 1. The output Q gives consequently the value 1 which indicates that the detection loop is intact. If the detection loop is broken, energy will not arrive at the second extremity of the detection loop. This means that the clock input has the value 1 and the D-input the value 0. The output Q gives consequently the value 0 which indicates that the detection loop is broken. This value is then supplied to the reading means and preferably also stored in the memory. By storing this value in the memory, which could for example be an EEPROM, it is possible to retrieve this value later, so that one could detect that the detection loop has been broken once. Preferably, a first identification codeword identifying the sealing device is stored in the memory 8, so that when checking a plurality of sealing devices each having an own first identification codeword, they can be distinguished from each other. Preferably, the electronic component 2 also comprises counter means for memorising how many times the object, onto which the device has been applied, has been sealed. This could for example be realised by providing that said first codeword comprises several bits which are each time incremented by the logic component when a change in state of the sealing device, i.e. broken or intact has occurred. For example, the first codeword has value 0000. When the detection loop is connected to the electronic component, the logic component increases the first codeword into a second codeword 0001 , upon powering up the sealing device. When the detection loop is broken the second codeword changes into a third codeword 0010. When the detection loop, preferably a new one, is connected, value 0011 is given and so on. Thus, a value 0101 means that the object has been sealed 2 times and is now closed. A value 1000 means that the object has been sealed 4 times and is now open. Preferably, the memory 8 is provided for being stored with a second identification codeword by means of writing means, which second identification codeword identifies the content of the object to be sealed. This enables a user, upon reading the content of the memory by means of the reading means, to check what the content of the sealed object is. The detection loop in the embodiment according to Figure 3 could also be a light conductive or optical loop instead of a galvanic conductive loop. In this case, the second extremity 11 of the detection loop would check the presence of energy in the form of light. Figures 4 and 5 illustrate possible embodiments of the electronic component 2, using known transmission technologies. Figure 4 illustrates the FM technology and Figure 5 the AM technology. These techniques are known as such and will therefore not be described further in detail. The described embodiments illustrate that the energy is supplied by the reading means. It is clear that energy could also be provided by another external source. It is also conceivable that a power supply is additionally provided in the sealing device. In this case, the sealing device remains in sleeping mode and becomes operable when it is powered up by the external source. Instead of current or light, acoustic energy could also be used. The illustrated communication means have been illustrated as communication coils. It is clear that other communication means could be used such as for example an antenna, in particular a dipole antenna. This type of communication means could be used if communication is performed at a high frequency, whereas the coils are provided for performing communication at a low frequency.

Claims: CLAIMS 1. A sealing device provided for being applied onto an object to be sealed, said device comprising an electronic component with a memory, which component is connected to a detection loop provided for letting energy circulating through it and to be broken upon breaking said sealing device, said component being further connected to communication means for communicating with reading means, characterised in that said communication means comprise a communication loop provided for receiving power for powering up said sealing device. 2. A device according to claim 1 , characterised in that it said communication loop is provided for receiving power from said reading means. 3. A device according to claim 1 or 2, characterised in that said detection loop is connected in parallel with the communication loop. 4. A device according to any one of the claims 1 to 3, characterised in that a capacitance is provided in the detection loop. 5. A device according to any one of the claims 1 to 3, characterised in that an inductance is provided in the detection loop. 6. A device according to claim 1 or 2, characterised in that it comprises means provided for generating a first codeword upon establishing that the detection loop is intact and a second codeword upon establishing that the detection loop is broken. 7. A device according to claim 6, characterised in that said memory is connected to counter means provided for memorising how many times the object, onto which the device has been applied, has been sealed. 8. A device according to any one of the claims 1 to 7, characterised in that a first identification codeword for identifying said device is stored in said memory. 9. A device according to any one of the claims 1 to 8, characterised in that said memory is provided for being stored with a second identification codeword by means of writing means, which second identification codeword identifies the content of the object to be sealed. 10. A device according to claim 1 or 2, characterised in that said detection loop is an optical loop.

Inventors: LINDQVIST FRANK, LINDQVIST HENRIK, LINDQVIST, FRANK, LINDQVIST, HENRIK
Applicants: FYRTECH MICROELECTRONICS AB, LINDQVIST FRANK, LINDQVIST HENRIK, FYRTECH MICROELECTRONICS AB., LINDQVIST, FRANK, LINDQVIST, HENRIK
Application year: 1997
Main classification: G06K19
IPC codes: B42D15, G06K19