EP4164893A1

EP4164893A1 - Valuable document having a substrate element and a foil element, and method for classifying a valuable document

Info

Publication number: EP4164893A1
Application number: EP21736243.3A
Authority: EP
Inventors: Henning Geiseler; Thomas Happ; Thomas Giering
Original assignee: Giesecke and Devrient Currency Technology GmbH
Current assignee: Giesecke and Devrient Currency Technology GmbH
Priority date: 2020-06-10
Filing date: 2021-06-02
Publication date: 2023-04-19
Also published as: US20230226841A1; WO2021249671A1; EP3922476A1

Abstract

The invention relates to a valuable document (1) having a substrate element (2) and a foil element (4) arranged in a portion (3) of the substrate element (2), the substrate element (2) having, at least in the portion (3), a luminescent marker (5) which is designed to emit luminescent radiation (6) which has at least a first wavelength (7) and a second wavelength (8) each in the infrared spectral range, and the foil element (4) having a reflective layer (9) and a spectrally selective layer (10), the selective layer (10) being arranged between the substrate element (2) and the reflective layer (9), the reflective layer (9) being designed to reflect infrared radiation, and the selective layer (10) being designed to inhibit transmission of infrared radiation in a spectrally selective manner, the inhibition of the transmission of the first wavelength (7) and the inhibition of the transmission of the second wavelength (8) differing by at least 10%.

Description

Value document with a carrier element and a film element, and method for classifying a value document

The invention relates to a document of value with a carrier element and a film element. The invention also relates to a method for classifying a corresponding document of value.

It is known to make documents of value, in particular banknotes, more forgery-proof by forming banknotes with a luminescent security marker or a luminescence marker in or on the paper substrate or polymer substrate.

Furthermore, documents of value, in particular bank notes, usually have a film element in addition to a carrier element, for example a paper substrate or a polymer substrate. The film element is often glued to the carrier element.

A growing class of counterfeit banknotes, however, relates to so-called composed banknote counterfeits, which have different proportions of real banknotes and forged portions, for example photocopied portions. Counterfeiters detach the foil element, which is usually designed as a Level 1 security feature such as a foil strip or a foil patch, from a real banknote or cut it off. The real film element is then applied to an imechtes Trä gerelement, for example. Furthermore, a real film element, for example a photocopy, can also be applied to the real carrier element on which the real film element was previously attached.

A manipulated bank note with a real foil element on a fake carrier element can be recognized as manipulated by known methods by detecting a luminescence marker in the carrier element. In contrast, to detect manipulation of the second tampered bank note with a forged foil element on a real Trä gerelement a further safeguarding of the foil element and a corresponding test procedure with suitable sensors. A conventional luminescent marker in the carrier element can therefore only protect composite banknotes to a limited extent. Correspondingly, two separate methods can be useful for identifying both types of composite counterfeit banknotes.

The object of the invention is to create a solution as to how the forgery-proofness of a document of value can be increased with a carrier element and a film element.

According to the invention, this object is achieved by a document of value and by a method having the features according to the respective independent claims. Advantageous embodiments of the invention are the subject of the dependent claims.

A value document according to the invention, in particular a bank note, has a carrier element and a film element arranged in a partial area of the carrier element. The carrier element has a luminescence marker at least in the partial area. The luminescence marker is set up to emit luminescence radiation. The luminescence radiation has at least a first wavelength and a second wavelength. The first wavelength and the second wavelength are each formed in the infrared spectral range. The first and second wavelengths are preferably different by more than 30 nm, more preferably by more than 50 nm, particularly preferably by more than 100 nm. Furthermore, the film element has a reflective layer and a spectral selection layer. The selection layer is arranged between the carrier element and the reflective layer. The reflective layer is designed in particular to intentionally reflect infrared radiation. The selection layer is designed to spectrally selectively inhibit transmission of infrared radiation. The inhibition of the transmission of the first wavelength and the inhibition of the transmission of the second wavelength are different by at least 10%, in particular at least 20%, given in absolute percentage points.

The invention is based on the knowledge that a more secure document of value can be provided with the reflective layer and the spectral selection layer in the film element. The luminescence marker in the carrier element and the Seleküonsschicht as well as the reflective layer in the foil element create a composite security feature which can be used to check whether the combination of carrier element and foil element is genuine. The present invention improves the detection reliability of manipulated documents of value such as composite banknotes by combining the luminescent markers or an IR-luminescent security marker (IR = infrared) on or in the carrier element with the spectral selection layer, in particular an IR absorber with a specific spectral signature , in the film element, for example a security thread, security strip or security patch.

Furthermore, a more comprehensive identification of manipulated or composite value documents with a single, combined method using a single sensor is possible.

The film element is, in particular, a layered security element, e.g. hologram patch, security thread or strips with micromirrors, microlenses or other optically variable elements that contain an IR absorber substance.

The foil element is designed in such a way that the IR absorber does not have to be detected in transmission, as was previously the case, but instead takes place indirectly by measuring the IR-luminescent luminescent marker in remission geometry from the side of the document of value facing away from the foil element. The excitation of the luminescence or the luminescence feature or the luminescence marker is carried out in particular from the side of the value document facing away from the film element. The light emitted by the luminescent IR luminescent marker interacts in particular with the spectral selection layer in the film element and is reflected in particular by the broadband reflective or scattering reflective layer in the film element, and passes through the carrier element of the document of value in order, for example, to be subsequently detected by a detector .

The reflective layer reflecting in a directional or diffuse manner due to scattering throws back, for example, at least 50%, preferably at least 80%, of the incident luminescent light.

The carrier element or banknote substrate can be, for example, a paper substrate, for example made of cotton, a polymer substrate, for example made of BOPP (biaxially oriented polypropylene), or a hybrid substrate made of a paper core with outer polymer layers (hybrid) or act from a polymer core with outer paper layers. In particular is the carrier element for the infrared luminescence radiation is translucent, that is, at least part of the luminescence radiation impinging on the carrier element or generated in the volume of the carrier element can penetrate the carrier element and emerge from the surface of the carrier element. This can be a directional transmission or the radiation transport can also be diffusive and thus non-directional due to corresponding scatter contributions.

The luminescent marker is preferably embedded in the volume of the carrier element during the respective paper or polymer production or, alternatively, applied to an inner surface in the case of hybrid substrates or to an outer surface. In addition to the usual printing techniques such as offset printing, intaglio printing, flexographic printing, screen printing or digit printing, full-surface coatings or lines are also possible.

The luminescence marker preferably emits infrared radiation in the wavelength range from 750 nm to 2500 nm, in particular from 800 nm to 2200 nm.

The structure and properties of the film element are preferably matched to the IR luminescence marker in order to be able to more effectively demonstrate the presence of the same via the interaction of the luminescence radiation with the spectral selection layer in the film element.

The reflection layer and the selection layer are in particular formed separately, preferably at a distance.

It is preferably provided that the film element is designed as a layered security element. Due to the layer-like structure, the selection layer can be arranged effectively and safely between the reflective layer and the carrier element. The security of the document of value is increased.

The structure of the film element can, however, also be significantly more complex and consist of several polymer layers, for example several plastic layers (foils), lacquer layers and adhesive layers, and also have several metallic and / or dielectric layers. In particular, some layers can be transparent or translucent or opaque, have different layer thicknesses, consist of different materials and are continuous or partially cut out or printed in the form of patterns or letters. In particular, all layers between the carrier element and the selection layer and / or between the selection layer and the reflection layer are transparent or translucent for IR light. In particular, this means that the reflectivity of the reflective layer is at least 50%, at least for the first or second wavelength, even when measured from the surface of the film element facing the carrier element, i.e. preferably through all layers between the carrier element and the reflective layer through, is achieved.

The foil element itself is preferably designed in such a way that the selection layer is located in an inner layer of the foil element, and thus when the foil element is detached it inevitably detaches from the banknote with it.

Furthermore, it is preferably provided that the film element is designed as a hologram and / or security thread and / or security strip. The reflective layer of the film element can thereby have two functions. A first function, such as the visual protection against forgery by means of an iridescent hologram, and a second function, the reflection property for the luminescent radiation. This in turn makes the value document more secure.

Furthermore, it is preferably provided that the film element is designed with at least one optically variable element, in particular a micromirror array and / or a microlens array. An optically variable element is characterized in particular by an appearance that is dependent on the viewing angle or the angle of incidence of light. The formation as an optically variable element is advantageous, since optically variable elements often have a reflective metal layer, which can also be used as the reflective layer. The forgery-proof nature of the document of value can also be further increased by the optically variable element.

The reflective layer can have a directed or a diffuse (scattering) reflectivity. For example, the reflective layer can be a metal layer or a metal layer stack, for example made of Al, or a white colored layer, for example T1O2. Furthermore, it is preferably provided that the film element is applied, in particular at least partially, to a surface of the carrier element. The film element is preferably firmly connected to the carrier element. The film element can for example be glued or welded onto the carrier element.

Furthermore, it is preferably provided that the reflective layer and the selection layer are designed to overlap when viewed perpendicular to the carrier element, in particular perpendicular to the main extension direction of the carrier element. This means in particular that radiation from the luminescence marker in the partial area which passes through the selection layer also hits the reflection layer. After the reflection, the radiation reflected by the reflection layer arrives again in particular at the selection layer and passes through it again.

Furthermore, it is preferably provided that the selection layer is designed as an absorption layer. The absorption layer is designed in particular to at least partially absorb infrared radiation. By absorbing the infrared radiation, the intensity of this radiation can be inhibited. In particular, the absorption layer is designed to absorb at least the first wavelength and / or the second wavelength or to reduce the respective intensities of the wavelengths. The absorption layer is preferably formed to absorb or inhibit the intensities of the wavelengths to different degrees. Furthermore, the absorption layer can be designed to inhibit incident radiation only in part of the incident spectrum, the selection spectral range. Compared to a reflective selection layer, an absorption layer preferably has a simpler structure and is therefore easier and cheaper to integrate into a film element.

In one embodiment, the selection layer can be designed as a spectrally selectively reflecting selection layer. As a result, the first wavelength can be reflected by the selection layer and the second wavelength can penetrate the selection layer. In this case, the reflective layer is preferably designed as a broadband absorbing layer. In this case, it can also be the case that a further broadband absorbing layer is arranged between the selection layer and the reflection layer.

Furthermore, it is preferably provided that the reflection layer has a reflection spectral range and the selection layer has a selection spectral range, the Reflection spectral range is broader than the selection spectral range. A broader range of the infrared radiation from the Lumineszenzmarker is reflected by the reflective layer than is inhibited by the selection layer. Due to the broader reflection spectral range, the reflection layer can be used at the same time for visual effects of the film element in the visible spectral range.

Furthermore, it is preferably provided that the reflective layer is set up to reflect at least 50%, preferably at least 80%, of a luminescent radiation emitted by the luminescence marker and incident on the reflective layer. This reflection property can then be used to detect reflected luminescence radiation in order to form a clearer spectral signature. The value document is made more secure as a result.

Furthermore, it is preferably provided that the luminescence marker is embedded in the carrier element. For example, the luminescent marker or the luminescent material can already be introduced into the carrier element during production thereof. The luminescent marker can, for example, be introduced into the paper in the case of a carrier element designed as paper. This is advantageous because the luminescence marker is thereby detachably connected to the carrier element and the value document is made more secure.

In addition or as an alternative, the luminescence marker can also be applied to a surface of the carrier element. The luminescent marker can be arranged on the side of the carrier element facing away from the film element, so that the luminescent radiation falls through the carrier element onto the film element, in particular the selection layer and the reflective layer. The luminescence marker can, however, also be arranged on the side facing the film element, in particular between the carrier element and the film element.

In particular, the value document has a multiplicity of luminescence marker particles as the luminescence marker. The luminescence marker particles are preferably distributed, in particular completely, in the carrier element or over the carrier element.

Furthermore, it is preferably provided that the document of value has a document class-specific spectral signature which is dependent on a luminescence radiation emitted by the luminescence marker and incident on the selection layer, and in particular on the reflective layer. The spectral signature is in particular made up of intensity values formed by several different infrared spectral ranges. The different spectral ranges are preferably filtered or inhibited differently by the selection layer, as a result of which the spectral signature is created. By means of the spectral signature, the value document and structurally identical value documents can be assigned to a common class and separated from value documents of different types.

In one embodiment, the reflective layer can be designed to be broadband, diffusely reflective. Furthermore, the selection layer can be formed as an absorptive edge filter. In particular, the film element can be designed with a visual feature comprising a microlens array with an underlying diffusely reflective, optionally printed, white color layer. The white paint layer can serve as a reflective layer.

The invention also relates to a method. In the method according to the invention, a document of value is classified with a carrier element having a luminescence marker and a film element with a reflective layer arranged in a partial area of the carrier element. The following steps are carried out: a) Excitation of the luminescence marker with radiation, in particular infrared radiation, from an excitation side of the value document, the excitation side being the side of the value document facing away from the film element; b) detecting an intensity of the luminescent radiation emitted by the excited luminescence marker and reflected by the reflective layer, the detection being carried out in particular from the side facing away from the film element; bl) In particular, determining a spectral signature on the basis of the detected intensity; c) comparing the detected intensity, in particular the determined spectral signature, with a reference intensity, in particular a spectral reference signature; and d) classifying the value document on the basis of the comparison.

It was surprisingly found that the detection of the intensity of the luminescence radiation, which is reflected by the reflective layer, in particular on the side of the carrier element facing away from the foil element, leads to a more forgery-proof spectral signature or combination signal curve than a direct detection of the luminescence radiation alone which takes place without the detour via the reflective layer. It is preferably provided that the luminescence radiation emitted by the excited luminescence marker is spectrally inhibited or filtered by a selection layer of the film element before it is detected in step b). The selection layer is preferably designed as an absorption layer. The selection layer inhibits at least a spectral portion of the luminescent light striking the selection layer from penetrating the selection layer, ie at most only part of the intensities of the inhibited wavelengths reach the reflection layer. A clear spectral signature or combination signal curve can be generated by the selection layer. The value document can thereby be classified more securely, and the presence and authenticity of the film element can be proven.

Furthermore, it is preferably provided that the luminescence radiation emitted by the excited luminescence marker first hits the selection layer and only then hits the reflective layer. After striking the reflective layer, the radiation reflected by the reflective layer may pass through the selection layer again before it is detected. The Seleküonsschicht is accordingly arranged in particular between the carrier element and the reflective layer.

Furthermore, it is preferably provided that at least a first intensity of a first wavelength and a second intensity of a second wavelength are detected as the detected intensity, in each case in the infrared spectral range. Due to the at least two detected wavelengths, the spectral signature can be formed with a higher information content, whereby the value document can in turn be formed more securely.

Furthermore, it is preferably provided that a direct luminescence intensity of the luminescence marker outside the sub-area, in particular within a further sub-area different from the sub-area, is recorded on the direct propagation path and in step d) the classification based on the direct luminescence intensity and that recorded in step b) Intensity is carried out. The direct luminescence intensity is recorded directly, that is to say without having been reflected by the reflective layer.

Furthermore, it is preferably provided that the reference intensity is provided by a direct luminescence intensity of the luminescence marker recorded outside of the sub-area and on the direct path of propagation. The further sub-area in particular also includes the luminescence marker, but is arranged outside of the overlap area with the film element. In particular, the foil element is only present in the sub-area and not in the further sub-area.

It is then preferably provided that the recorded intensity of the further sub-area is compared with the recorded intensity of the sub-area. In other words, the intensity that is detected by a luminescence marker outside the sub-area is compared with the intensity that is detected by a luminescence marker within the sub-area. The intensity of the further sub-area or outside the sub-area can be used or provided as the reference intensity. The use of the intensity of the further sub-area as a reference intensity is also referred to as self-reference.

Furthermore, it is preferably provided that the combination intensity detected in step b) comprises luminescence radiation which is emitted by the excited luminescence marker in the direction of the film element, is then spectrally inhibited in the spectral selection layer of the film element, then reflected by the reflective layer and then again by the spectral selection layer is spectrally inhibited.

The preferred embodiment presented with reference to the method according to the invention and their advantages apply accordingly to the value document according to the invention. The objective components of the document of value according to the invention are designed to carry out the respective steps of the method.

Further features of the invention emerge from the claims, the figures and the description of the figures.

Embodiments of the invention are explained in more detail below with reference to a schematic drawing.

Show: 1 shows a schematic representation of an exemplary embodiment of a document of value according to the invention with a carrier element and a film element, where the carrier element has a luminescence marker;

2 shows a schematic representation of a further exemplary embodiment of the Wertdo document, the luminescent marker being arranged on the side of the carrier element facing away from the film element;

3 shows a schematic representation of a further exemplary embodiment of the Wertdo document, the film element being embedded in the carrier element;

4 shows a schematic representation of a further exemplary embodiment of the Wertdo document, the luminescent marker being arranged on the side of the carrier element facing the film element;

5 shows a schematic representation of a method for classifying a document of value with a carrier element and a film element;

6 shows a schematic representation of excitation radiation for exciting the luminescence marker and luminescence radiation which is given off by the luminescence marker;

7 shows a schematic representation of a luminescence spectrum, an absorption spectral range and a spectral signature;

8 shows a further schematic representation of a luminescence spectrum, a sorption spectral range and a spectral signature;

9 shows a schematic representation of a luminescence spectrum, a selection spectral range in the form of a band absorber filter and a spectral signal; 10 shows a schematic representation of a luminescence spectrum, a selection spectral range designed as a low-pass filter and a spectral signature; and

11 shows a schematic representation of a luminescence spectrum, a selection spectral range designed as a high-pass filter, and a spectral signature.

Identical or functionally identical elements are provided with the same reference symbols in the figures.

1 schematically shows an exemplary embodiment of a value document 1. The value document 1 has a carrier element 2. The carrier element 2 in turn has a partial area 3.

A film element 4 is arranged in sub-area 3. Furthermore, the carrier element 2 has a luminescence marker 5 in the sub-area 3. In particular, the luminescence marker 5 is designed as a multiplicity of, preferably powdery, particles.

The luminescence marker 5 is designed to emit luminescence radiation 6. The luminescence radiation 6 has at least a first wavelength 7 in the infrared spectral range and a second wavelength 8 in the infrared spectral range.

The luminescent substance used for the luminescent security marker or luminescent marker 5 can be, for example, organic, organometallic or inorganic luminescent substances. The excitation of the luminescent substances is preferably in the visible or infrared spectral range. Particularly suitable luminescent substances will be de NEN both excitation and emission in the infrared spectral range, since special DERS low scattering losses and thus very high intensities at the rear measurement by the carrier element 2 through _V orkommen.

Examples of such luminescent substances are inorganic pigments doped with one or more rare earth elements, in particular with the dopants neodymium or ytterbium or erbium or thulium or holmium, or doped with certain transition metals. The combination of ytterbium with a further dopant is preferred, in particular their erbium, thulium, neodymium or holmium. Furthermore, organometallic complexes, in particular with neodymium or holmium or erbium or thulium or ytterbium, or certain organic substances can be used.

A single luminescent substance or a mixture or a combination of several luminescent substances can be used for the luminescent marker 5. In the latter case, the first and the second wavelength of the luminescence emission can be emitted by the same luminescent substance or by different luminescent substances of the luminescent marker 5.

In addition to the luminescent marker 5, the document of value 1 can comprise further feature substances which increase the security against forgery, for example further luminescent substances. Several luminescence markers 5 with different spectral signatures can also be combined in the value document 1. For example, the luminescence marker 5 can be present as a mixture with the further feature substance, or the luminescence marker 5 and the further feature substance can be present at different locations on the value document 1, for example in the volume or on one or both surfaces of the value document 1.

The first wavelength 7 can be 1100 nm, for example. The second wavelength 8 can be 1600 nm, for example.

According to the exemplary embodiment, the film element 4 has a reflection layer 9 and a spectral selection layer 10. The selection layer 10 is arranged between the support element 2 and the reflective layer 9. According to the exemplary embodiment, the reflection layer 9 and the selection layer 10 are arranged parallel to one another.

The reflective layer 9 is designed to reflect infrared radiation, in particular the luminescent radiation 6.

The selection layer 10 is designed to spectrally selectively inhibit the transmission of infrared radiation, in particular the luminescence radiation 6. The inhibition of transmission through the selection layer 10 at the first wavelength 7 is at least 10% more or less than the inhibition of transmission of the second wavelength 8, given in absolute percentage points. If the transmission through the selection layer 10 amounts to the first If the wavelength 7 is 50%, for example, the transmission through the selection layer 10 at the second wavelength 8 is preferably either at least 60% or at most 40%.

The selection layer 10 is preferably designed as a spectrally selective absorption layer. This means that the absorbing selection layer 10 at least partially absorbs certain wavelengths or wavelength ranges. In particular, the selection layer 10 has an IR absorber.

For example, inorganic, organometallic or organic pigments or dyes are used for the IR absorber in the selection layer. The absorber layer is preferably printed on during the production of the film element. The IR absorber is then in particular in the form of pigment particles or a dye embedded in a printing ink. Suitable inorganic pigments can include, for example, oxides, halides, phosphates, chalcogenides, vanadates, silicates or germanates of transition metals (e.g. Zn, Ti, V, Cr, Mn, Fe, Co, Ni, Cu) or rare earth elements (e.g. Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb). Suitable organometallic compounds are, for example, phthalocyanines or naphthalocyanines. Suitable organic compounds are e.g. Cu H2Pc or porphyrins.

The structure of the document of value 1 enables a measurement 11 in remission geometry. For this purpose, according to the exemplary embodiment, the luminescence marker 5 is excited, for example by irradiation with light, in particular infrared light. The irradiation takes place in particular from a side 12 of the carrier element 2 facing away from the film element 4.

The luminescence marker 5 emits the luminescence radiation 6 due to the excitation. The luminescence radiation 6 in turn propagates in the carrier element 2 and at least partially hits the selection layer 10. Only part of the spectrum is blocked through the selection layer 10, or it may even be that the entire spectrum range of the luminescence radiation 6, preferably in different ways Degree in terms of intensity, is inhibited. The luminescence radiation 6 which has penetrated the selection layer 10 or exits on the side of the selection layer 10 facing away from the carrier element 2 therefore has in particular a different spectral signature than before entering the selection layer 10. The luminescence radiation, at least partially inhibited by the selection layer 10 or changed with regard to the spectral intensities, hits the reflection layer 9. The luminescence radiation 6 is at least partially reflected by the reflection layer 9 and at least partially passes through the selection layer 10 again the luminescent radiation 6 the carrier element 2 and can then be detected on the side 12 of the carrier element 2 facing away from the film element 4. For the detection, for example, a detector is arranged on the opposite side 12.

It may be that when the reflected luminescence signal or the reflected luminescence radiation 6 is detected, not only reflected luminescence radiation is detected, but also a combined portion of directly emitted luminescence radiation.

According to the exemplary embodiment, the film element 4 is designed as a layer-like security element. The security element is characterized in that it is difficult to reproduce without special manufacturing equipment and special manufacturing knowledge. The film element is preferably designed as a hologram and / or security thread and / or security strip.

According to the exemplary embodiment, the film element 4 is arranged on a surface 13.

According to the exemplary embodiment, the reflective layer 9 and the selection layer 10, viewed perpendicular to the carrier element 2, are designed to overlap at least in some areas. For example, the reflective layer 9 and the selection layer 10 are designed to completely overlap. For example, the reflection layer 9 and the selection layer 10 are formed exactly one above the other in register.

The reflection layer 9 has a reflection spectral region 14. The selection layer 10 has a selection spectral range 15. According to the exemplary embodiment, the reflection spectral region 14 has a broader band than the selection spectral region 15. This means that the reflection spectral region 14 or the reflection layer 9 reflects a larger wavelength range than the selection spectral region 15 or the selection layer 10 inhibits. This is advantageous because it also gives broadband reflective metal layers for the Reflective layer can be used, which can simultaneously provide other functions of the film element, such as a reflection hologram.

FIG. 2 shows the document of value 1 analogously to FIG. 1, but the luminescence marker 5 according to this exemplary embodiment is arranged on the opposite side 12 of the carrier element 2. For example, the luminescence marker 5 can be printed on or applied to the carrier element 2 as a paint on the back.

In addition, the luminescence marker 5 can also be embedded in the carrier element 2, as shown in FIG. 1.

FIG. 3 shows the document of value 1 likewise analogously to FIG. 1. However, according to the exemplary embodiment of FIG. 3, the film element 4 is embedded in the carrier element 2. This means, for example, that the carrier element 2 has a recess 16 into which the film element 4 is introduced or embedded or integrated. It may be that the film element 4 is incorporated into the carrier element during the production of the carrier element 2. For example, the film element 4 can only be surrounded by the carrier element 2 on one side or it can also be completely surrounded on all sides by the carrier element 2. This is especially the case when the film element 4 is designed as a completely embedded security thread or only in some areas of a security thread that is partially embedded as a so-called window thread.

The luminescence marker 5 is arranged in the carrier element 2 according to the exemplary embodiment in FIG. 3. However, it can also be the case that the luminescence marker 5 in the exemplary embodiment of FIG. 3 is arranged on the carrier element 2 only outside of the carrier element 2, for example as shown in FIG. 2. Furthermore, it can also be the case that the luminescence marker is both embedded in the carrier element 2 and at the same time is worn on an outside of the carrier element 2.

4 shows a further embodiment of the document of value 1 analogous to FIG. 1. According to the embodiment of FIG. 4, however, the luminescence marker 5 is located on the surface 13 of the carrier element 2 between the film element 4 and the carrier element 2. are also formed in the carrier element 2. 5 shows an exemplary embodiment of a method for classifying the document of value 1. Shown is an excitation unit 17 which excites the luminescence marker 5 with excitation radiation 26, for example light. The excited luminescent marker 5 emits the luminescent radiation 6 after the excitation process. According to the exemplary embodiment, the luminescence radiation 6 is emitted at least at the first wavelength 7 and the second wavelength 8.

At least a portion of the luminescence radiation 6 strikes the selection layer 10, which is optionally present during the process and is not shown in the figure, is at least partially spectrally inhibited there, ie. H. Intensities of selected wavelengths of the luminescence radiation 6 are reduced or emerge from the selection layer 10 with less strength than into the selection layer 10. After the selection layer 10, the luminescence radiation 6, which is at least partially inhibited or changed with regard to the spectral intensities, hits the reflective layer 9 and is thrown back from there to the selection layer 10, i.e. reflected, penetrates the selection layer 10 again, also penetrates the carrier element 2 and is finally outside of the carrier element 2, detected on the opposite side 12 of the carrier element 2 by a detection unit 18. The detection unit 18 is formed, for example, as a spectrometer and / or has at least two detection units. A first detection unit is preferably designed to detect the first wavelength 7 but not the second wavelength 8, and a second detection unit is designed to detect the second wavelength 8 but not the first wavelength 7. The detection area on the document of value 1 is preferably smaller than the extent of the foil element 4. The first detection unit and the second detection unit preferably have essentially the same detection area.

6 shows, in a schematic representation, an exemplary embodiment of the method in which an excitation radiation 26 for exciting the luminescence marker 5 is emitted in the direction of the carrier element 2. The excitation radiation 26 preferably has only a single wave length. After excitation of the luminescence marker 5, the excitation radiation 26 continues to radiate with reduced intensity, in the exemplary embodiment penetrates the selection layer 10 and strikes the reflective layer 9. The excitation radiation 26 is reflected by the reflective layer 9, emitted again through the selection layer 10 and strikes the Lumi again nescence marker 5 to stimulate it again with reduced intensity. After the renewed excitation, the excitation radiation 26 then leaves the carrier element 2 with a further reduced intensity on the side 12 facing away from the film element 4. Furthermore, the first wavelength 7 of the luminescence radiation 6 is shown, which after the excitation is emitted by the luminescence marker 5, in particular in all spatial directions. The luminescence radiation emitted at the first wavelength 7 in the direction of the film element penetrates the carrier element 2 and the selection layer 10 is essentially uninhibited. The first wavelength 7 is then reflected on the reflective layer 9 and again penetrates the selection layer 10, essentially in an essentially inhibited manner. Furthermore, the first wavelength 7 also penetrates the carrier element 2 and can be detected on the side 12 facing away from the film element 4.

The first wavelength 7 is, however, emitted in a non-directional manner, which is why the first wavelength 7 exits the carrier element unchecked on the opposite side 12 even without passing through the selection layer 10.

In addition, the second wavelength 8 is also shown, which is also emitted after the excitation by the luminescence marker 5, in particular in all spatial directions. The luminescence radiation emitted at the second wavelength 8 in the direction of the film element penetrates the carrier element 2 uninhibited and strikes the selection layer 10. The selection layer 10, according to the exemplary embodiment, is designed to inhibit the second wavelength 8, ie the second wavelength 8 leaves the selection layer 10 weakened or with less intensity than before entering the selection layer 10. At the reflection layer 9, the second wavelength 8 is also reflected back to the selection layer 10 and passes through the selection layer 10 again, the second wavelength 8 when passing through the selection again onsschicht 10 is further weakened. The second wavelength 8 then penetrates the carrier element 2 and leaves it on the opposite side 12.

The second wavelength 8 is also emitted in a directionally directed manner, which is why the second wavelength 8 emerges uninhibited from the carrier element on the side 12 facing away, even without passing through the selection layer 10.

7 shows an exemplary embodiment of a document class-specific spectral signature 19. It can be seen that the spectral signature 19 has a dent 20. The dent 20 arises, for example, at the point of the second wavelength 8. The dent 20 arises from the fact that the selection layer 10 inhibits the intensity of the second wavelength 8. In comparison to the spectral signature 19, a normal curve 22 and an absorption-free curve 23 are shown. The normal curve 22 arises when the reflective layer 9 is not present and only the direct luminescence radiation of the luminescence marker 5 is detected, for example outside of the sub-area 3. The absorption-free curve 23 arises when the selection layer 10 is not present, and thus the selective one There is no inhibition, but the reflective layer 9 is present, for example in the case of a forged film element. The dent 20 is then not present in the latter case.

The wavelength in nm is plotted on an abscissa 24 of the diagrams according to FIGS. 6 to 11. The signal strength is plotted on an ordinate 25 of the diagrams, for example in units of the photocurrent of a photodiode.

8 shows an embodiment of a spectral signature 19. The spectral signature 19 is formed by the selection spectral range 15, in particular the absorption spectral range or absorption spectrum, and a luminescence spectrum 27 or emission spectrum of the luminescence marker 5. In this embodiment, the luminescence spectrum 27 has two spectral bands . These spectral bands can, for example, be emitted by two different luminescent substances which together form the luminescent marker 5. The luminescence spectrum 27 can correspond to the normal curve 22 from FIG. 7.

9 shows a further exemplary embodiment in a schematic representation of the spectral signature 19. The spectral signature 19 is formed by the luminescence spectrum 27 and the narrow-band selection spectral range 15.

10 shows a further exemplary embodiment in a schematic representation of the spectral signature 19. The spectral signature 19 is formed by the luminescence spectrum 27 and the selection spectral range 15 designed as a low-pass filter.

11 shows a further exemplary embodiment in a schematic representation of the spectral signature 19. The spectral signature 19 is formed by the luminescence spectrum 27 and the selection spectral range 15 designed as a high-pass filter. In a further exemplary embodiment, a document of value 1 is produced. A carrier element 2 made of paper is provided over the entire surface with a luminescent marker 5, which consists of two luminescent substances, both of which can be excited at the same wavelength or the same excitation radiation 26, and the first luminescent substance luminescent radiation 6 at 1100 nm - corresponding to the first wavelength 7 - Emits, and the second luminescent substance luminescent radiation at 1600 nm - corresponding to the second wavelength 8 - emits. A security strip is additionally applied to this carrier element 2 on the front side 13 in a partial area 3 as a foil element 4. The security strip has a visual level 1 feature consisting of a microlens structure with an underlying printed white larb layer. The white larb layer also serves as a reflective layer 9. In addition, the foil element 4 has an IR absorber layer as a selection layer 10 below the white larb layer. In this exemplary embodiment, the IR absorber layer consists of a security printing ink with broadband varying absorption, which has an absolute absorption of approx. 50% at 1100 nm and an absolute absorption of only 10% at 1600 nm. The structure of the value document corresponds to Lig. 1, the spectral relationships to Lig. 11.

The value document 1 is manipulated, for example, by removing the foil element 4 and replacing it with a piece of aluminum foil for a simple forgery of an impression. The fake foil element differs from the real foil element 4 in particular in that it does not have a selection layer 10.

For the authenticity check according to lig. 5 and lig. 6, a sensor in remission geometry is used, which in particular has at least one excitation unit 17 and one detection unit 18. The value document 1 is transported past the sensor by a transport device, the sensor taking at least one measurement of the luminescence radiation 6 in the sub-area 3 and at least one further measurement of the luminescence radiation 6 outside the sub-area 3. For this purpose, the value document 1 is illuminated with excitation 26, which is set up to excite both luminescent substances of the Lumineszenzmark kers 5 to emit luminescence. The luminescence radiation 6 emerging on the rear side 12 of the document of value 1 is detected by the detection unit 18, a first detection unit only detecting the luminescence intensity at 1100 nm and a second detection unit only detecting the luminescence intensity at 1600 nm. Seen from the sensor A broadband absorbing, for example black, surface is located behind the document of value transported past.

The authenticity of the carrier element 2 is verified by the presence of the luminescence radiation 6 at the first wavelength 7, in particular 1100 nm, and at the second wavelength 8, in particular 1600 nm. The recorded intensities of the luminescence radiation 6 at the first wavelength 7 and the second wavelength 8 are in particular in a fixed ratio that is characteristic of the luminescence marker 5, which is determined or measured there during the measurement outside the sub-area 3 (luminescence spectrum 27 in FIG . 11). In the present embodiment, this ratio is preferably 1.0.

In the measurements in the sub-area 3, the measured luminescence intensities or intensities are significantly higher due to the influence of the reflective layer 9 of the film element 4. For example, the measured intensities at wavelengths 7 and 8 are increased by approx. 50% in the presence of a film element with a reflective layer 9.

If the film element has the IR absorber layer 10 that is characteristic of a real film element 4, the measured intensity at the first wavelength 7, in particular 1100 nm, is, however, about 10% lower than at the second wavelength 8 due to the interaction with this selection layer , in particular 1600 nm, which is particularly characteristic of the spectral signature 19. The authenticity of the film element 4 can therefore be checked on the basis of the measured ratio between the luminescence intensity at the first wavelength 7 and the luminescence intensity at the second wavelength 8. As a decision criterion is the difference of the intensity _V erhältnisse outside of the portion 3 and is used in the subregion. 3 If the intensity ratio measured in sub-area 3 is, for example, more than 0.07 smaller than outside sub-area 3, the presence and authenticity of film element 4 is considered to be confirmed, otherwise the checked document of value 1 is rejected.

Claims

1. Document of value (1) with a carrier element (2) and a film element (4) arranged in a sub-area (3) of the Trä gerelements (2), the carrier element (2) having a luminescence marker (5) at least in the sub-area (3) which is set up to emit luminescence radiation (6) which has at least a first wavelength (7) and a second wavelength (8) each in the infrared spectral range, and wherein the film element (4) has a reflective layer (9) and a spectral Has selection layer (10), the selection layer (10) being arranged between the carrier element (2) and the reflective layer (9), the reflective layer (9) being designed to reflect infrared radiation, and the selective layer (10) designed to do so is to inhibit the transmission of infrared radiation spectrally selectively, the inhibition of the transmission of the first wavelength (7) and the inhibition of the transmission of the second wavelength (8) at least 10% different are noble.

2. Document of value (1) according to claim 1, wherein the film element (4) is designed as a layered security element.

3. Document of value (1) according to claim 1 or 2, wherein the film element (4) is designed as a patch and / or hologram and / or security thread and / or security strip.

4. Document of value (1) according to one of the preceding claims, wherein the film element (4) is applied to a surface (13) of the carrier element (2).

5. Document of value (1) according to one of the preceding claims, wherein the reflective layer (9) and the selection layer (10) perpendicular to the carrier element (2) are designed to be overlapping.

6. Document of value (1) according to one of the preceding claims, wherein the selection layer (10) is designed as an absorption layer.

7. Value document (1) according to one of the preceding claims, wherein the reflective layer (9) has a reflective spectral range (14), and the selection layer (10) has a selection spectral range (15), wherein the reflective spectral range (14) is broader than the selection spectral range (15).

8. Value document (1) according to one of the preceding claims, wherein the reflective layer (9) is set up to reflect at least 50% of a luminescent radiation (6) emitted by the luminescent marker (5) and incident on the reflective layer (9).

9. Document of value (1) according to one of the preceding claims, wherein the luminescence marker (5) is embedded in the carrier element (2).

10. Value document (1) according to one of the preceding claims, wherein the value document (1) has a document class-specific spectral signature (19) which depends on a luminescence radiation (6) emitted by the luminescence marker (5) and incident on the selection layer (10) is.

11. A method for classifying a document of value (1) with a luminescence marker (5) having a carrier element (2) and a film element (4) arranged in a partial area (3) of the carrier element (2) with a reflective layer (9), in which the following steps are carried out: a) excitation of the luminescence marker (5) with radiation from an excitation side of the document of value (1), the excitation side being the side (12) of the document of value (1) facing away from the film element (4); b) detecting an intensity of the infrared luminescence radiation (6) emitted by the excited luminescence marker (5) and reflected by the reflective layer (9); c) comparing the detected intensity with a reference intensity; and d) classifying the document of value (1) on the basis of the comparison.

12. The method according to claim 11, wherein the luminescence radiation (6) emitted by the excited luminescence marker (5) is spectrally inhibited by a Seleküonsschicht (10) of the film element (4) prior to detection in step b).

13. The method according to claim 11 or 12, wherein at least a first intensity of a first wavelength (7) and a second intensity of a second wavelength (8) in each case in the infrared spectral range are detected as the detected intensity.

14. The method according to any one of claims 11 to 13, wherein a direct luminescence intensity of the luminescence marker (5) outside the sub-area (3) is detected on the direct path of propagation, and in step d) the classification based on the direct luminescence intensity and the in step b) recorded intensity is carried out.

15. The method according to any one of claims 11 to 14, wherein the reference intensity is provided by a direct luminescence intensity of the luminescence marker (5) recorded outside the sub-area (3) and on a direct propagation path.