TWI625676B - Device and method for contactless excitation - Google Patents

Abstract

The invention relates to a device for non-contact excitation of at least one electroluminescent pigment, in particular in a value or security document, wherein the device comprises at least one electrode, wherein the at least one electrode is designed such that the electrode can be A change in the electric flux density of one of the fields generated in the predetermined radiation direction, and a method for non-contact excitation.

Description

Device and method for non-contact excitation Field of invention

The present invention relates to an apparatus and method for non-contact excitation of at least one electroluminescent pigment, particularly in a value or security document.

Background of the invention

Valuable or secure documents such as banknotes, ID documents, credit cards and the like may have so-called preservation or authenticity features applied to or in the document. These security features can be excited, for example, from the outside and analyzed during or after the excitation. A typical authenticity feature is a fluorescent pigment that illuminates during excitation by a special sensor and can thus be verified.

It is also known to arrange electroluminescent pigments in or on a value or security document.

EP 1 631 461 B1 discloses a value document having at least one security element, the at least one security element comprising a marking layer in the marking zone, the marking layer comprising an electroluminescent pigment coated on the carrier, wherein the arrangement is distributed in the marking zone a plurality of field shifting elements, each electrically isolated from the environment and having a dielectric constant greater than 50, the field shifting elements having each other An average distance of about 5 μm to 500 μm is used to form a gap for the electroluminescent pigment, and it locally increases the magnitude of the giant embossed electric field in the gap.

DE 10 2008 047 636 A1 discloses a device for checking the authenticity of a security document having at least one security feature of electroluminescence at an excitation frequency in a high voltage alternating field, the device having a sensor unit It includes an excitation module, a concentrator system, and a detector unit. The security file is moved through the sensor unit and the emitted light is collected by the concentrator system and directed to the detector unit, which captures and spectrally evaluates the emitted light. Here, the excitation module has a slot-shaped opening that overlaps the path of motion of the security document to be inspected by the opposing boundary surfaces of the opening.

DE 199 03 988 A1 describes a device for verifying the authenticity characteristics of valuable and security documents, in particular banknotes, ID documents, plastic cards and the like, which are fed by the banknote to be inspected and in the process of doing so It consists of an automatic test device that passes through the detector device. The detector device is adapted to capture and evaluate the electroluminescent properties of the authenticity features.

In order to motivate the electroluminescent pigment in the value or preservation document, it is necessary to bridge, for example, an air distance between the electrode and the value or security document. During this process, the dielectric strength of the air forms a limiting factor for the excitation field. In the configuration of the prior art, for the locally occurring air distance, an excitation frequency of 30 kHz and a maximum amplitude of an excitation voltage of 30 kV are generated.

It is necessary to integrate the device for authenticity checking into, for example, a decentralized small banknote testing device or ATM. For this reason, it is necessary to reduce the installation space of this device.

Existing devices for authenticity inspection do not adequately meet these requirements.

A technical problem has arisen that creates an apparatus and method for non-contact excitation of at least one electroluminescent pigment that allows for reliable and targeted excitation by a reduction in the maximum amplitude of the alternating voltage to be generated.

The solution to this technical problem is derived from the objectives with the characteristics of claims 1 and 9. Further advantageous embodiments of the invention are derived from the dependent claims.

Summary of invention

The main idea of the invention is to design the electrodes of the device for non-contact excitation such that the field lines of the electric field generated by the electrodes are locally concentrated. Thus, a spatial increase in the flux density can be achieved, which advantageously permits improved and more reliable excitation of the electroluminescent pigment.

According to a first aspect of the invention, a device for non-contact excitation of at least one electroluminescent pigment, in particular in a value or security document, is proposed. The electroluminescent pigment can be included in one of the valuable or security documents. Thus, the device can also be adapted to non-contactly excite at least one security element of a valuable or security document having an electroluminescent pigment.

The device can thus be part of a document testing device by which the security features or security components of the value or security document can be verified.

“Preservation Document” means protected by unwarranted features Any document of the production and/or forgery of the right. The security feature is at least hindering the falsification and/or replication of its features compared to simple copying. An entity that contains or forms a security feature is called a security component. The security component can include a plurality of security features and/or security components. Within the meaning of the definitions provided here, the security document also always constitutes a security component. Examples of security documents that also contain valuable documents representing value include passports, government-issued ID cards, driver's licenses, identity cards, access control cards, health insurance cards, banknotes, stamps, bank cards, credit cards, smart cards, tickets, and labels. .

The device comprises at least one electrode. In this context, the device contains exactly one electrode system possible. The electrodes are used to generate an electric field, which is also referred to below as an excitation field. When an alternating voltage is applied to the electrodes, an electric field is generated. Hereinafter, the alternating voltage applied to the electrodes is referred to as an excitation voltage. The excitation voltage can be generated by an alternating voltage source. It is also possible that the excitation voltage is the output voltage of the transformer, wherein the input voltage of the transformer is generated by an alternating voltage source. The AC voltage source can, for example, comprise a DC voltage source and an inverter, wherein the AC voltage is the output voltage of the inverter.

Therefore, if an excitation voltage is applied to the electrodes, an electric field is generated, and the field lines extend away from the electrodes.

Additionally, at least one electrode is designed such that the electric flux density of the electric field that can be generated by the electrode in a predetermined direction of radiation changes. In particular, the electrical flux density increases and forms at least a maximum.

The predetermined direction of radiation may indicate the direction from which the electrode is directed to the price or to preserve the document. In particular, the direction of radiation of the electrodes can be oriented perpendicular to the surface of the value or security document. The direction of radiation can also be parallel to the central longitudinal axis of the electrode The wire is oriented away from the free end of the electrode.

The fact that the electric flux density of the electric field which can be generated by the electrode in the predetermined radiation direction changes means that the flux density changes in a cross-sectional plane oriented perpendicular to the predetermined radiation direction of the electrode. In particular, at least one spatial region having a higher flux density than in adjacent regions may be present in the cross-sectional plane.

For example, the flux density can vary along one direction perpendicular to the direction of radiation. In this context, the flux density can be varied continuously (ie, not abruptly) in the cross-sectional plane. For example, the flux density can be varied linearly or exponentially, especially increasing or decreasing.

This advantageously produces at least one zone with an increased electrical flux density via the configuration of the electrodes. In particular, field focus can occur as a result of the spatial concentration of the electric field. This achieves a reliable excitation of at least one electroluminescent pigment, since improved excitation is also possible by the concentration of the excitation field.

In addition, advantageously, it becomes possible to reduce the amplitude of the excitation voltage. Since higher flux densities and higher amplitudes result in improved or stronger excitation of the electroluminescent pigment, the amplitude can be reduced due to at least one zone having a high flux density, wherein the intensity of the excitation remains at least constant.

The reduction in the amplitude of the excitation field, in turn, advantageously avoids the adverse effects of high amplitudes (such as plasma formation in the air gap, dielectric breakdown, fields of high field strength, radiation behavior that is not appreciated by us, Electromagnetic interference and high energy consumption of other electronic components are possible.

Additionally, the device has a plurality of electrodes, wherein the electrodes are Each of them is designed such that the electric flux density of the field that can be generated by the electrodes in a predetermined radiation direction changes. Accordingly, the device comprises a plurality of electrodes designed in accordance with one of the embodiments explained above.

According to the invention, all of the electrodes have a common direction of radiation.

In this case, in a cross-sectional plane oriented perpendicular to all directions of radiation, the presence of a plurality of zones having a maximum electrical flux density is particularly possible. This advantageously promotes the excitation of the electroluminescent pigment if the exact location of the electroluminescent pigment (e.g., in a value or security document) is not known. In particular, the proposed device produces a resulting excitation field for a plurality of regions having a maximum flux density. If the resulting excitation field, for example, is applied to a valuable or security document having at least one electroluminescent pigment, the probability of at least one electroluminescent pigment being disposed in a region having a high or maximum flux density is increased. Of course, a plurality of (especially large amounts) of electroluminescent pigments can also be excited by this electrode. For example, electroluminescent pigments having a size in the nanometer region may be present and randomly distributed in the security document. As an example, an electroluminescent pigment in an excitation region having a diameter of 1 mm can then be excited by an electrode having an outer diameter of, for example, 100 μm. The great advantage of using a plurality of electrodes is that the excitation region and thus the illumination surface become larger.

In still another embodiment, the electrical flux density of the excitation field changes in a predetermined region of the cross-sectional plane oriented perpendicular to the predetermined radiation direction of the electrode. Here, the predetermined area is penetrated by the entire electric field (which is an excitation field, generated by an electrode) or a predetermined portion of the electric field. Thereby, the size of the zone in the plane of the cross section is described. The predetermined portion can be defined, for example, by a predetermined percentage (eg, 95%, 90%, or 85%).

Thus, in this regard, the change in flux density occurs in the region of the cross-sectional plane that is penetrated by the excitation field or a predetermined portion thereof. Thus, in detail, there is no constant flux density in this zone, such as for a plate capacitor.

It is also possible that the predetermined area is equal to or smaller than the area contained by the boundary of the electrode projected in the plane of the cross section. If the outer diameter (especially the maximum outer diameter) of the proposed electrode is projected in the plane of the cross section, the zone can thus be comprised by the boundary forming the largest outer diameter.

In particular, the flux density of the change in the predetermined zone may have exactly one maximum.

The proposed device advantageously enables the electrode to produce a local spatial concentration of the field lines in the direction of the radiation, whereby the reliability of the excitation of the at least one electroluminescent pigment is increased as previously described.

In still another embodiment, the electrical flux density is higher in at least a portion of the predetermined area of the cross-sectional plane than in other portions of the predetermined area. For example, the electric flux density can be higher than 1 x 10 ^-7 C/m ² . As previously explained, the electric flux density is higher in a portion of the predetermined area of the cross-sectional plane than in all remaining portions. This produces exactly one zone with a high flux density. This allows for targeted and reliable excitation of at least one electroluminescent pigment by electrodes as proposed.

In still another embodiment, the at least one electrode tapers toward the radiation end. In this respect, the radiating end of the electrode indicates the end from which the excitation field (especially its field line) is emitted from the electrode, in particular towards at least one of the value or preservation files. In particular, the radiating end can be the free end of the electrode.

In this regard, it is progressively smaller, for example, indicating a decrease in diameter, wherein, for example, the diameter can be measured perpendicular to the central longitudinal axis. As explained previously, the central longitudinal axis in this aspect may be parallel or equal to the predetermined direction of radiation.

The gradual decrease leads to an increase in the flux density of the excitation field radiated in the radiation direction (especially in the case of an increase in the degree of gradual decrease), because the gradual decrease causes field focus.

This advantageously results in an easily implementable design of the at least one electrode.

In still another embodiment, the electrode has a conical section. Alternatively, the electrode can have a tapered section.

Here, the proposed section is designed such that the electrode tapers towards the radiation end.

The above-described shape of the segments thus advantageously allows the desired field focus to be achieved while allowing for a simple construction of the electrodes.

In yet another embodiment, the electrodes are designed as wires. The wire can be made, for example, of a conductive material. Thus, for example, the wire can be made of copper, silver or gold, however, preferably made of carbon fiber.

The wire can have a predetermined maximum diameter. This maximum diameter can be, for example, 1 mm. A diameter of up to 0.1 mm is preferred. For larger diameters, the tapered wire ends (especially the pointed wire ends) are advantageous.

The wire-shaped design advantageously results in high field focusing and electrodes that are particularly easy to manufacture.

In still another embodiment, the distance from the electrode to the adjacent electrode is less than or Equal to the predetermined maximum distance. Here, the distance can be measured perpendicular to the radial direction. In particular, all of the electrodes may thus extend parallel to each other, wherein, for example, the central longitudinal axes of the electrodes are oriented parallel to each other.

In this context, the distance between the individual electrodes also determines the distance of the region of high velocity density in the resulting excitation field. By selecting the distance, the spatial distribution of the zone with high or maximum flux density can thus be implemented as desired.

The predetermined maximum distance can be, for example, 5 mm.

It is possible to arrange the electrodes in a comb shape. In this context, the individual electrodes form the teeth of the comb structure. The electrodes can also be arranged in a matrix. In this context, individual electrodes form a matrix and rows of matrices. In a matrix configuration, the distance and direction of at least one adjacent electrode from the column direction and/or the row direction is constant.

It is also possible to arrange the electrodes in a cluster or bundle. In this context, the distribution of the electrodes in the previously explained cross-sectional plane cannot have a defined pattern, but rather has a random pattern. For example, in a random pattern, the distance and direction from adjacent electrodes can vary.

Advantageously, a uniform distribution of the regions having a high or maximum flux density is also produced by the uniform distribution of the electrodes in the plane of the cross section. This may be particularly advantageous when the electroluminescent pigments are disposed in a security document (eg, where the distances are also as identical as possible to each other).

In a clustered or bundled configuration of electrodes, advantageously, it can be seen that the spatial distribution of the regions of the excitation field with high or maximum flux density is also random. When, for example, the electroluminescent color is randomly configured in a price or security document This is especially advantageous when feeding. For example, when the pigment is added to the printed color as usual or the pigment is randomly distributed therein during the production of the substrate, a random distribution of the pigment is produced.

Additionally, the electrodes can be configured such that the electrodes include or enclose an area in which the optical sensors and/or optical elements for beam steering are disposed. For example, the electrode can include a region in which a channel that serves as an optical acquisition channel is disposed in this region. For example, an optical sensor and/or other optical component can be disposed in the channel.

For example, the zone can be the zone enclosed by the connecting wires of the electrodes. Here, the zone can have a predetermined size. Therefore, the electrodes can be arranged around the member for optical acquisition.

In still another embodiment, the plurality of electrodes are in electrical contact with one another. Advantageously, therefore, an excitation voltage can be applied to a plurality of electrodes simultaneously, whereby the excitation fields generated by the individual electrodes are also phased identically.

At the same time, and advantageously, the required installation space is reduced and the electrical contact of the individual electrodes is simplified.

In summary, the proposed device makes it possible, for example, to design a document testing device for verifying a valuable or security document with at least one electroluminescent pigment with the smallest possible installation space.

In addition, advantageously, it can thus be seen that especially in the case where a plurality of electrodes are in electrical contact with one another, the circuitry required for the proposed device can be minimized. The proposed electrode form advantageously makes it possible to have only a small installation space for the electrodes. The previously described possibility of reducing the amplitude of the excitation voltage advantageously results in fewer other interference effects. Therefore, the electromechanical of the proposed device can be improved compatibility. It also reduces the energy consumption in generating an excitation field.

This also describes a file testing device that includes the previously explained device. The document testing device can be designed, for example, as a battery operated portable handheld device or as part of such a handheld device. For example, the document testing device can have a pin-shaped design in which the electrodes are disposed on a tapered section of the pin. By means of this pin, advantageously a simple verification of the value or security document can be performed whereby the user manually aligns the pin with respect to the value or security document.

Here, the document testing device may also include other component parts, such as the previously explained AC voltage source and transformer.

Alternatively, the device can be integrated into a file testing device (eg, a fixedly configured file testing device) to check, for example, a value or security document in a machine readable manner for security features.

Particularly in a second alternative, the document testing device can, for example, comprise an optical acquisition facility for acquiring radiation emitted by at least one electroluminescent pigment. This acquisition facility can be an image capture facility such as a CCD camera, a light sensor (eg, a photodiode), or other components for spectral acquisition of the emitted light. The test device can also include other optical components (eg, lenses or mirrors) for redirecting and/or focusing the emitted radiation.

Valuable or security documents may be incorporated into the document testing device, for example, such that the surface perpendicular to the value or security document is oriented to the previously interpreted direction of radiation.

The at least one electrode may also be configured relative to the value or security document such that the distance between the electrode and the surface of the valued or secured document is at most 20 mm, preferably at most 5 mm. The minimum distance can be 0mm, making electricity The poles and documents touch each other. However, especially in the case where the electrode is not protected against mechanical abrasion, preferably, the distance is at least 0.5 mm.

According to a first aspect of the invention, a device for non-contact excitation of at least one electroluminescent pigment, in particular in a value or security document, is additionally proposed. Here, an electrical alternating voltage is applied to at least one of the electrodes. The electrical alternating voltage applied to the electrodes can also be referred to as the excitation voltage. At least one electrode is designed such that the electric flux density of the field produced by the electrode in a predetermined direction of radiation changes. To this end, the electric field forms an excitation field. Thus, the electrodes are designed in accordance with one of the previously described embodiments. The device for non-contact excitation has a plurality of electrodes, wherein each of the electrodes is designed such that the flux density of the field that can be generated by the electrode in a predetermined direction of radiation changes. According to the invention, all of the electrodes have a common direction of radiation.

Here, the method can be performed by a device according to one of the previously described embodiments.

In addition, the electrodes can be aligned such that the direction of radiation is directed to a price or security document, particularly perpendicular to the surface orientation of the value or security document.

In addition, an electrical alternating voltage can be generated such that the amplitude of the excitation voltage is in the region of 100V to 5kV. The frequency of the excitation voltage can also be adjusted. The frequency can be especially in the region of 30 kHz to 20 MHz. Preferably, the excitation frequency is in the region of 70 kHz to 100 kHz.

The excitation voltage can have a different shape. For example, the excitation voltage can be a square wave voltage, a triangular voltage, a trapezoidal voltage, however, preferably, it is a sinusoidal voltage.

According to still another aspect of the present invention, in order to solve the technical problem, The device may be adapted to non-contactly excite at least one electroluminescent pigment, in particular in a value or security document, wherein the device comprises at least one electrode, wherein the at least one electrode is designed such that the field generated by the electrode in a predetermined direction of radiation The electric flux density changes. According to still another aspect, in order to solve the technical problem, a method may be additionally adapted to non-contactly excite at least one electroluminescent pigment, in particular in a value or preservation document, wherein an electrical alternating voltage is applied to at least one electrode, wherein the at least one The electrodes are designed such that the electric flux density of the electric field generated by the electrodes in a predetermined direction of radiation changes. In this context, devices according to other aspects may be further developed to have technical features suitable for further development of the device according to the first aspect. In this context, methods according to other aspects may be further developed to have technical features suitable for further development of the method according to the first aspect. These further developments have the same advantages as further development of the apparatus and method according to the first aspect. In this context, methods according to other aspects can be performed by devices according to other aspects.

1‧‧‧ device

2‧‧‧Priced or preservation documents

3‧‧‧DC voltage source

4‧‧‧Inverter

5‧‧‧Transformers

6, 14‧‧‧ electrodes

7‧‧‧Inspired field

8‧‧‧Central longitudinal axis

9‧‧‧ Radiation direction

10‧‧‧radiation end

11‧‧‧Conical section

12‧‧‧ cross section plane

13‧‧‧Predetermined area

15‧‧‧ surface

16‧‧‧Security components

17‧‧‧Luminous radiation

18‧‧‧Electrode configuration

19‧‧‧ District

20‧‧‧ recess

21‧‧‧Optical acquisition facility/optical sensor

22‧‧‧Connecting line

23‧‧‧Shell

24‧‧‧ bottom surface

The invention is explained in more detail using a plurality of execution examples. The figures show: Figure 1 is a schematic block diagram of a device for non-contact excitation of at least one electroluminescent pigment, Figure 2a is a cross section through an electrode according to the invention, and Figure 2b is through another electrode Cross-section, Figure 3 is a schematic representation of an electrode and a valuable or security document in accordance with the present invention, 4 is a schematic representation of a cluster electrode configuration and a valuable or security document, FIG. 5 is a plan view of the cluster electrode arrangement shown in FIG. 4, FIG. 6 is a plan view of another electrode configuration, and FIG. 7 is a view of FIG. The electrode configuration and the schematic representation of the price or security document.

Detailed description of the preferred embodiment

Hereinafter, the same reference symbols indicate elements having the same or similar technical features.

In Fig. 1, a schematic block diagram of a device 1 for non-contact excitation of at least one electroluminescent pigment (not shown) in a value or preservation document 2 (e.g., see Fig. 3) is shown. The device 1 comprises a DC voltage source 3, for example a battery. The DC voltage source 3 is electrically connected to an inverter 4 also included in the device 1. The inverter 4 can convert the output voltage of the DC voltage source 3 to an AC voltage having a predetermined excitation frequency. On the output side, the inverter 4 is electrically connected to the transformer 5. The transformer 5 converts the alternating voltage generated by the inverter 4 to an excitation voltage having a desired amplitude. On the output side, the transformer 5 is connected to a schematically shown electrode 6, wherein an excitation voltage generated by the transformer 5 is applied to the electrode 6. Here, as explained in more detail below, the electrode 6 produces an excitation field 7.

Thus, the electrical excitation field can be generated by a resonant circuit in which the resonant frequency of the resonant circuit can be selected to be higher than the previous normal excitation frequency of up to 30 kHz. This advantageously permits a reduction in the voltage amplitude of the excitation voltage.

Therefore, the installation space of the components of the resonant circuit can be reduced. Harmonic The oscillating circuit can be, for example, composed of at least a primary inductance of the transformer and a capacitance of the electrode. In the prior art device for document testing, an excitation frequency of 30 kHz and an excitation voltage having an amplitude of up to 30 kV were used.

A high excitation frequency advantageously requires a high rate of change (dU/dt) of the field reversal of the electrical excitation field. Since the emission excitation of the electroluminescent pigment also depends on the rate of change of the excitation field, the amplitude of the excitation voltage can be reduced. By reducing the amplitude of the excitation voltage, the energy to be stored in the resonant circuit (and therefore the magnetic energy or electrical energy to be stored) is also reduced. This advantageously allows for a reduction in the installation space of, for example, a transformer. For example, the installation space required for a ferrite core for a transformer that is used to store magnetic energy can be reduced due to lower energy. At the same time, the reduction in the maximum voltage of the excitation voltage causes, for example, a reduced isolation requirement for the windings of the transformer. This again leads to a reduction in the required installation space. In addition, this avoids or limits the heating that the system is not happy with.

Additionally, advantageously, reducing the amplitude of the excitation voltage also results in improved operational safety of the transformer. It can be stored at a reduced amplitude of the excitation voltage (eg, for a human user) that can become less dangerous to the user (eg, when touched).

The excitation voltage can have a maximum amplitude of 6 kV. In this regard, the excitation field 7 (see, for example, Figure 2a) is adapted to excite the electroluminescent pigment in the value or preservation document 2.

Figure 2a shows a cross section through an electrode 6 according to the invention. The electrode 6 has a central longitudinal axis 8. Also shown is the radiation direction 9 of the electrode 6. This is oriented parallel to the central longitudinal axis 8. The electrode 6 gradually becomes smaller toward the radiation end 10. In this respect, the electrode 6 has a conical section 11 at the radiating end 10. another In addition, Figure 2a shows a plot of the field line of the excitation field 7, which extends away from the electrode 6. In the cross-sectional plane 12 oriented perpendicular to the radiation direction 9, the electric flux density of the excitation field 7 changes. In detail, the electric flux density changes in the predetermined zone 13, wherein the predetermined zone is penetrated by the entire electric excitation field 7 generated by the electrode 6. Here, it is shown that the flux density increases from the point at which the edge of the zone 13 intersects the central longitudinal axis 8 to the cross-sectional plane 12. Therefore, the spatial distribution of the electric flux density of the excitation field 7 has exactly one region with the largest flux density.

Figure 2b shows the other electrode 14 in cross section. Also shown is a cross-sectional plane 12 oriented perpendicular to the central radiation direction 9 of the electrode 14. A region 13 penetrated by the entire excitation field generated by the electrodes is also shown. However, in contrast to Figure 2a, the electrical flux density does not increase toward the point at which the central longitudinal axis 8 of the electrode 14 intersects the cross-sectional plane 12. This does not achieve the desired local spatial concentration of the field lines that allow reliable excitation of the electroluminescent pigment.

Figure 3 shows a schematic representation of the electrode 6 and the value or preservation document 2. For this purpose, the electrode 6 is arranged relative to the value or security document 2 such that the radiation direction 9 of the excitation field 7 produced by the electrode 6 is oriented perpendicular to the surface 15 of the value or security document 2 . On the surface 15, a security element 16 comprising an electroluminescent pigment (not shown) is disposed. These pigments can be excited by the electrical excitation field 7 such that they emit luminescent radiation 17. By the physical design of the electrode 6, a region having a high electrical flux density of the excitation field 7 is produced in the region of the security element 16. If the electroluminescent pigment is disposed in this region, the electroluminescent pigment can also be excited if a relatively low excitation voltage (e.g., having an amplitude between 100 V and 5 kV) is used.

Figure 4 shows a surface 15 that is configured on a value or security document 2 The schematic configuration of the valuable or security document 2 and electrode arrangement 18 of the security component 16 above. The electrode arrangement 18 comprises a plurality of electrodes 6 whose radiation directions 9 are parallel to each other. Each of the electrodes 6 produces an excitation field 7 (not shown) (see, for example, Figure 2a), which is designed to correspond to the explanation given with respect to Figure 2a. All of the electrodes 6 are in electrical contact with each other, wherein in Fig. 4, a transformer 5 is shown whose output voltage (i.e., excitation voltage) is simultaneously applied to all of the electrodes 6.

FIG. 5 shows a plan view of the electrode configuration 18 shown in FIG. This shows that the individual electrodes 6 are arranged in a cluster or bundle. Here, the distance and direction from the respective next adjacent electrodes 6 vary between the individual electrodes 6. Thus, a random spatial configuration of the electrodes 6 is created which also results in a random spatial distribution of regions having a high or maximum flux density of the excitation field 7.

With the electrode configuration shown in Figure 5, the excitation surface is advantageously increased, and thus the light emitting surface of the security element 16 (e.g., see Figure 4) is also increased. In order to minimize wear, one of the electrodes 6 or all of the electrodes 6 of the electrode arrangement 18 can be cast into a plastic material, especially in high voltage and well isolated plastic materials, for example, in UV cured epoxy compounds, 2K epoxy. A resin compound, a polyoxyxasiloxane, a thermoplastic polyurethane (TPU) compound or an injection molded polymer material compound. This advantageously avoids the formation of corona at the tip end of the electrode 6, while at the same time minimizing wear.

FIG. 6 shows a plan view of another advantageous electrode configuration 18. Here, the electrode 6 of the electrode arrangement 18 is configured such that the electrode 6 comprises a zone 19 in which the recess 20 is disposed. Zone 19 can be, for example, a zone 19 enclosed by a connecting line 22 of electrodes 6. For example, the connection line 22 of the electrode 6 can be circular. Therefore, the electrodes 6 are arranged on a circular line at a predetermined distance from each other, wherein the round There is a predetermined radius. Other forms of configuration are of course also conceivable, for example on a rectangular connection line.

The recess 20 or the opening can be designed, for example, as a blind hole or as a through hole (which is a hole open on both sides). The recess 20 can be cylindrical. For example, the connecting line 22 can be aligned with the axis of symmetry of the cylindrical recess 20.

The recess 20 can serve as an optical acquisition channel or form an optical acquisition channel, wherein radiation (eg, radiation emitted by the excited electroluminescent pigment) can reach the optical acquisition facility 21 (see Figure 7) or use by the recess 20. The eyes of the person.

Thus, it can be seen that the electrode 6 is arranged around the optical acquisition channel. This enables the excitation and detection of the emitted light to be made possible only from the common side of, for example, the value or security document 2.

FIG. 7 shows a schematic representation of the electrode configuration 18 and the value or preservation document 2 shown in FIG. The outer casing showing electrode arrangement 18 or electrode arrangement 18 is designed to resemble a hollow cylinder in which electrode 6 is disposed (e.g., cast) in shell section 23. The optical sensor 21 is disposed on the bottom surface 24 of the inner volume of the hollow cylinder that forms the recess 20.

The security element 16 of the value or preservation document 2, which contains an electroluminescent pigment (not shown), is applied with an excitation field 7 (see, for example, Figure 2a), wherein the radiation direction 9 of the excitation field 7 produced by the electrode 6 is perpendicular to the value. Or the surface 15 of the security document 2 is oriented. The luminescent radiation emitted by the electroluminescent pigment reaches the acquisition region of the optical sensor 21 via the recess 20. Of course, it is possible to arrange, for example, optical elements (e.g., lenses) for beam steering or beam focusing in the recess 20 that acts as an optical acquisition channel. For example, the optical sensor 21 can be light The electric diode is followed by an amplifier. The illustrated embodiment advantageously provides a structurally very compact design of a document testing device, particularly a portable document testing device.

The inverter 4 shown in Figure 1 can be designed, for example, as an oscillator circuit that includes, for example, an operational amplifier circuit and two FETs as push-call end stages. For example, transformer 5 can include a transformer coil wound on a ferrite core. For example, the electrode 6 can be connected only to the line of the circuit shown in Figure 1, for example, the winding of the coil of the transformer 5. Preferably, the excitation frequency of the excitation field 7 (e.g., see Fig. 2a) greater than the audio frequency (e.g., at a frequency between 30 kHz and 20 MHz, preferably in the region of 70 kHz to 100 kHz) is operated in Fig. 1. Show the circuit.

Claims (9)

A device particularly suitable for non-contact excitation of at least one electroluminescent pigment in a valuable or security document, wherein the device comprises at least one electrode, wherein the at least one electrode is designed such that it is produced by the electrode in a predetermined direction of radiation One of the fields has a change in electrical flux density, wherein the device has a plurality of electrodes, wherein each of the electrodes is designed such that the electrical flux density of the field that can be generated by an electrode in a predetermined direction of radiation changes. It is characterized in that all electrodes have a common radiation direction. A device according to claim 1, characterized in that in a predetermined region of a cross-sectional plane oriented perpendicular to the predetermined radiation direction of the electrode, an electric flux density is changed, wherein the predetermined region is generated by the electric field of the electrode All or part of a predetermined portion penetrates. The device of claim 2, wherein the electrical flux density is higher in at least a portion of the predetermined region of the cross-sectional plane than in other portions of the predetermined region. A device according to any one of claims 1 to 3, characterized in that the at least one electrode tapers towards a radiation end. A device according to claim 4, characterized in that the electrode has a conical or tapered section. A device according to claim 1, characterized in that the electrode is designed as a wire. The device of claim 1, characterized in that an electrode is from an adjacent electrode A distance is less than or equal to a predetermined maximum distance. The device of claim 1 characterized in that the plurality of electrodes are electrically contacted together. A method particularly suitable for non-contact excitation of at least one electroluminescent pigment in a valuable or security document, wherein an electrical alternating voltage is applied to at least one electrode, wherein the at least one electrode is designed such that the electrode is at a predetermined radiation One of the electric fields generated in the direction changes in electric flux density, wherein a device has a plurality of electrodes, wherein each of the electrodes is designed such that the electric flux of the field generated by an electrode in a predetermined radiation direction is Density change; characterized in that all electrodes have a common radiation direction.