Valuable document with a carrier element and a film element, and method for classifying a valuable document

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

[0001] The invention relates to a value document comprising a carrier element and a foil element. Furthermore, the invention also relates to a method for classifying such a value document.

[0002] It is known to make value documents, in particular banknotes, more forgery-proof by forming banknotes with a luminescent security marker or a luminescent marker in or on the paper substrate or polymer substrate.

[0003] Furthermore, valuable documents, especially banknotes, usually have a foil element in addition to a carrier element, for example a paper substrate or a polymer substrate. The foil element is often glued to the carrier element.

[0004] However, a growing class of banknote counterfeits involves so-called composite banknote counterfeits, which contain varying proportions of genuine banknotes as well as counterfeit components, such as photocopied components. Counterfeiters detach or cut out the foil element, which is usually a Level 1 security feature such as a foil strip or patch, from a genuine banknote. The genuine foil element is then applied, for example, to a fake carrier element. Furthermore, a fake foil element, such as a photocopy, can also be applied to the genuine carrier element, to which the genuine foil element was previously attached.

[0005] A tampered banknote with a genuine foil element on a fake carrier element can be detected as tampered using known methods by detecting a luminescent marker in the carrier element. In contrast, detecting tampering with a second tampered banknote with a counterfeit foil element on a genuine carrier element requires further protection of the foil element and a corresponding verification procedure with suitable sensors.

[0006] A conventional luminescent marker in the carrier element can therefore only provide limited protection for composite banknotes. Accordingly, two separate processes may be useful for identifying both types of composite banknote counterfeits.

[0007] WO2020 / 048640 A1 and EP 1 935 663 A1 disclose value documents comprising a carrier element and a film element arranged in a partial region of the carrier element, wherein the carrier element has a luminescence marker at least in the partial region.

[0008] The object of the invention is to provide a solution for increasing the forgery security of a valuable document comprising a carrier element and a foil element. This object is achieved according to the invention by a valuable document and a method having the features according to the respective independent claims. Advantageous embodiments of the invention are the subject of the dependent claims.

[0009] A value document according to the invention, in particular a banknote, has a carrier element and a film element arranged in a partial region of the carrier element. The carrier element has a luminescence marker at least in the partial region. The luminescence marker is designed 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 in the infrared spectral range. The first and the second wavelength preferably differ 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 the transmission of infrared radiation. The inhibition of the transmission of the first wavelength and the inhibition of the transmission of the second wavelength differ by at least 10%, in particular at least 20%, expressed as absolute percentage points.

[0010] The invention is based on the finding that a more secure value document can be provided with the reflective layer and the spectral selection layer in the foil element. The luminescent marker in the carrier element and the selection layer and the reflective layer in the foil element create a composite security feature that can be used to verify whether the combination of carrier element and foil element is authentic.

[0011] The present invention improves the detection security of manipulated value documents such as composite banknotes by combining the luminescence marker 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.

[0012] Furthermore, a more comprehensive identification of manipulated or composite value documents is possible with a single, combined method using a single sensor.

[0013] The film element is in particular a layered security element, e.g. hologram patch, security thread or strip with micromirrors, microlenses or other optically variable elements, which contains an IR absorber substance.

[0014] The film element is particularly designed such that the IR absorber does not have to be detected in transmission, as has previously been the case, but instead is detected indirectly by measuring the IR-luminescent luminescence marker in remission geometry from the side of the value document facing away from the film 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 IR-luminescent luminescence marker interacts in particular with the spectral selection layer in the film element and is reflected in particular by the spectrally broadband reflecting or scattering reflection layer in the film element. It passes through the carrier element of the value document to be subsequently detected, for example, by a detector.

[0015] The reflection layer, which reflects directly or diffusely by scattering, reflects, for example, at least 50%, preferably at least 80%, of the incident luminescent light.

[0016] 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 even a hybrid substrate consisting of a paper core with outer polymer layers (hybrid) or a polymer core with outer paper layers. In particular, the carrier element is translucent to the infrared luminescence radiation, meaning that at least a portion of the luminescence radiation striking the carrier element or generated within the volume of the carrier element can penetrate the carrier element and exit from the carrier element at its surface. This can be directed transmission, or the radiation can also be diffuse and thus non-directed due to appropriate scattering contributions.

[0017] The luminescent marker is preferably embedded in the volume of the carrier element during the respective paper or polymer production process, or alternatively, applied to an inner surface in the case of hybrid substrates or to an outer surface. In addition to conventional printing techniques such as offset printing, intaglio printing, flexographic printing, screen printing, or number printing, full-surface varnishing or coating can also be used.

[0018] 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.

[0019] The structure and properties of the film element are preferably matched to the IR luminescence marker in order to be able to detect the presence of the marker more effectively via the interaction of the luminescence radiation with the spectral selection layer in the film element.

[0020] The reflection layer and the selection layer are in particular formed separately, preferably spaced apart.

[0021] Preferably, the film element is designed as a layered security element. This layered structure allows the selection layer to be effectively and securely positioned between the reflective layer and the carrier element. The security of the valuable document is increased.

[0022] However, the structure of the film element can also be significantly more complex, consisting of multiple polymer layers, e.g., multiple plastic layers (films), lacquer layers, and adhesive layers, as well as multiple metallic and / or dielectric layers. In particular, some layers can be transparent, translucent, or opaque, have different layer thicknesses, be made of different materials, and be 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 to IR light.This means in particular that the reflectivity of the reflective layer of in particular at least 50% at least for the first or the second wavelength is also achieved when measuring from the surface of the film element facing the carrier element, i.e. preferably through all layers lying between the carrier element and the reflective layer.

[0023] 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 is therefore inevitably detached from the banknote when the foil element is detached.

[0024] 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 thus have two functions: a first function, such as visual counterfeit protection through an iridescent hologram, and a second function, the reflection property for luminescent radiation. This, in turn, makes the value document more secure.

[0025] Furthermore, it is preferably provided that the film element is formed 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 depends on the viewing angle or the angle of incidence of the light. The design as an optically variable element is advantageous because optically variable elements often have a reflective metal layer, which can then additionally be used as the reflective layer. The optically variable element can also further increase the forgery security of the value document.

[0026] The reflective layer can have a specular or diffuse (scattering) reflectivity. For example, the reflective layer can be a metal layer or a metal layer stack, e.g., made of Al, or a white paint layer, e.g., TiO 2 .

[0027] 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.

[0028] Furthermore, it is preferably provided that the reflection 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 region that passes through the selection layer also impinges on the reflection layer. After reflection, the radiation reflected by the reflection layer returns, in particular, to the selection layer and passes through it again.

[0029] 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. The absorption of the infrared radiation can inhibit the intensity of this radiation. 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. Preferably, the absorption layer is designed 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 a 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 more cost-effective to integrate into a film element.

[0030] In one embodiment, the selection layer can be designed as a spectrally selectively reflecting selection layer. This allows the first wavelength to be reflected by the selection layer, and the second wavelength to penetrate the selection layer. In this case, the reflection layer is preferably designed as a broadband absorbing layer. In this case, another broadband absorbing layer can also be arranged between the selection layer and the reflection layer.

[0031] Furthermore, it is preferably provided that the reflection layer has a reflection spectral range and the selection layer has a selection spectral range, wherein the reflection spectral range is broader than the selection spectral range. Thus, a broader range of the infrared radiation from the luminescent marker is reflected by the reflection layer than is inhibited by the selection layer. Due to the broader reflection spectral range, the reflection layer can simultaneously be used for visual effects of the film element in the visible spectral range.

[0032] Furthermore, it is preferably provided that the reflective layer is configured to reflect at least 50%, preferably at least 80%, of the luminescent radiation emitted by the luminescent marker and incident on the reflective layer. This reflective property then allows reflected luminescent radiation to be detected to form a clearer spectral signature. The value document is thus more secure.

[0033] Furthermore, it is preferably provided that the luminescent marker is embedded in the carrier element. For example, the luminescent marker or phosphor can be incorporated into the carrier element during its manufacture. For example, if the carrier element is made of paper, the luminescent marker can be incorporated into the paper. This is advantageous because the luminescent marker is thus permanently bonded to the carrier element, making the valuable document more secure.

[0034] Additionally or alternatively, the luminescence marker can also be applied to a surface of the carrier element. The luminescence marker can be arranged on the side of the carrier element facing away from the film element, so that the luminescence radiation passes through the carrier element onto the film element, in particular the selection layer and the reflection layer. However, the luminescence marker can also be arranged on the side facing the film element, in particular between the carrier element and the film element.

[0035] In particular, the value document comprises a plurality of luminescence marker particles as the luminescence marker. Preferably, the luminescence marker particles are distributed, in particular completely, in the carrier element or over the carrier element.

[0036] Furthermore, it is preferably provided that the value document has a document-class-specific spectral signature, which is dependent on luminescence radiation emitted by the luminescence marker and incident on the selection layer, and in particular on the reflection layer. The spectral signature is formed in particular from intensity values ​​of several different infrared spectral ranges. Preferably, the different spectral ranges are filtered or inhibited differently by the selection layer, thereby creating the spectral signature. The spectral signature allows the value document and identical value documents to be assigned to a common class and separated from value documents of different designs.

[0037] In one embodiment, the reflection layer can be broadband diffusely reflective. Furthermore, the selection layer can be designed 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 ink layer. The white ink layer can serve as a reflection layer.

[0038] The invention also relates to a method. In the method according to the invention, a valuable document is classified using a carrier element comprising a luminescent marker and a foil element with a reflective layer arranged in a partial area of ​​the carrier element. The following steps are performed: a) Exciting the luminescence marker with radiation, in particular infrared radiation, from an excitation side of the value document, wherein the excitation side is the side of the value document facing away from the film element; b) Detecting an intensity of the luminescence radiation emitted by the excited luminescence marker and reflected by the reflective layer, wherein the detection is carried out in particular from the side facing away from the film element; b1) In particular, determining a spectral signature based on 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 based on the comparison, wherein the luminescence radiation emitted by the excited luminescence marker is spectrally inhibited by a selection layer of the film element before detection in step b).

[0039] It was surprisingly found that the detection of the intensity of the luminescence radiation which is reflected by the reflection layer, in particular on the side of the carrier element facing away from the film 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 reflection layer.

[0040] The luminescence radiation emitted by the excited luminescence marker is spectrally inhibited or filtered by a selection layer of the film element before detection in step b). The selection layer is preferably designed as an absorption layer. The selection layer inhibits at least a spectral portion of the luminescence light striking the selection layer from penetrating the selection layer, i.e., at most, only a portion of the intensities of the inhibited wavelengths reach the reflection layer. The selection layer can generate a clear spectral signature or combination signal curve. The valuable document can thus be classified more securely, and the presence and authenticity of the film element can be verified.

[0041] Furthermore, it is preferably provided that the luminescence radiation emitted by the excited luminescence marker first strikes the selection layer and only then the reflection layer. After striking the reflection layer, the radiation reflected by the reflection layer may then pass through the selection layer again before being detected. The selection layer is therefore arranged in particular between the carrier element and the reflection layer.

[0042] 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, each in the infrared spectral range. The at least two detected wavelengths allow the spectral signature to be formed with a higher information content, which in turn allows the value document to be formed more securely.

[0043] Furthermore, it is preferably provided that a direct luminescence intensity of the luminescence marker outside the sub-region, in particular within a further sub-region different from the sub-region, is detected via a direct propagation path, and in step d), the classification is carried out based on the direct luminescence intensity and the intensity detected in step b). The direct luminescence intensity is detected directly, i.e., without being reflected by the reflective layer.

[0044] Furthermore, it is preferably provided that the reference intensity is provided by a direct luminescence intensity of the luminescence marker detected outside the partial area and on a direct propagation path.

[0045] The further sub-area also includes, in particular, the luminescence marker, but is arranged outside the overlap area with the foil element. In particular, the foil element is present only in the sub-area and not in the further sub-area.

[0046] It is then preferably provided that the detected intensity of the further sub-area is compared with the detected intensity of the sub-area. In other words, the intensity detected by a luminescence marker outside the sub-area is compared with the intensity 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.

[0047] 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, is then reflected by the reflection layer and is then spectrally inhibited again by the spectral selection layer.

[0048] The preferred embodiments and their advantages presented with reference to the method according to the invention apply accordingly to the value document according to the invention. The physical components of the value document according to the invention are designed to carry out the respective steps of the method.

[0049] Further features of the invention emerge from the claims, the figures and the description of the figures.

[0050] Embodiments of the invention are explained in more detail below with reference to a schematic drawing.

[0051] Showing: Fig. 1 shows a schematic representation of an embodiment of a value document according to the invention with a carrier element and a film element, wherein the carrier element has a luminescence marker; Fig. 2 shows a schematic representation of a further embodiment of the value document, wherein the luminescence marker is arranged on the side of the carrier element facing away from the film element; Fig. 3 shows a schematic representation of a further embodiment of the value document, wherein the film element is embedded in the carrier element; Fig. 4 shows a schematic representation of a further embodiment of the value document, wherein the luminescence marker is arranged on the side of the carrier element facing the film element; Fig. 5 shows a schematic representation of a method for classifying a value document with a carrier element and a film element; Fig.Fig. 6 shows a schematic representation of excitation radiation for exciting the luminescence marker and luminescence radiation emitted by the luminescence marker; Fig. 7 shows a schematic representation of a luminescence spectrum, an absorption spectral range, and a spectral signature; Fig. 8 shows a further schematic representation of a luminescence spectrum, an absorption spectral range, and a spectral signature; Fig. 9 shows a schematic representation of a luminescence spectrum, a selection spectral range designed as a band-pass absorber filter, and a spectral signature; Fig. 10 shows a schematic representation of a luminescence spectrum, a selection spectral range designed as a low-pass filter, and a spectral signature; and Fig. 11 shows a schematic representation of a luminescence spectrum, a selection spectral range designed as a high-pass filter, and a spectral signature.

[0052] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0053] Fig. 1 schematically shows an 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.

[0054] A film element 4 is arranged in the partial region 3. Furthermore, the carrier element 2 has a luminescent marker 5 in the partial region 3. In particular, the luminescent marker 5 is formed as a plurality of, preferably powder-like, particles.

[0055] 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.

[0056] 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. Luminescent substances with both excitation and emission in the infrared spectral range are particularly suitable, as these result in particularly low scattering losses and thus particularly high intensities during the rear-side measurement through the carrier element 2.

[0057] Examples of such luminescent substances are inorganic pigments doped with one or more rare earth elements, in particular with the dopants neodymium, ytterbium, erbium, thulium, or holmium, or doped with certain transition metals. The combination of ytterbium with another dopant, in particular erbium, thulium, neodymium, or holmium, is preferred. Furthermore, organometallic complexes, in particular with neodymium, holmium, erbium, thulium, or ytterbium, or certain organic substances can be used.

[0058] A single luminescent substance or a mixture or combination of several luminescent substances can be used for the luminescent marker 5. In the latter case, the first and second wavelengths of the luminescence emission can be emitted by the same luminescent substance or by different luminescent substances of the luminescent marker 5.

[0059] In addition to the luminescent marker 5, the value document 1 can comprise further feature substances that increase counterfeit security, for example, further luminescent substances. Multiple luminescent markers 5 with different spectral signatures can also be combined in the value document 1. For example, the luminescent marker 5 can be present as a mixture with the further feature substance, or the luminescent 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.

[0060] The first wavelength 7 can be, for example, 1100 nm. The second wavelength 8 can be, for example, 1600 nm.

[0061] 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 carrier element 2 and the reflection layer 9. According to the exemplary embodiment, the reflection layer 9 and the selection layer 10 are arranged parallel to one another.

[0062] The reflection layer 9 is designed to reflect infrared radiation, in particular the luminescence radiation 6.

[0063] 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 by the selection layer 10 at the first wavelength 7 is at least 10% more or less than the inhibition of transmission at the second wavelength 8, specified in absolute percentage points. If the transmission through the selection layer 10 at the first wavelength 7 is, for example, 50%, the transmission through the selection layer 10 at the second wavelength 8 is preferably either at least 60% or at most 40%.

[0064] Preferably, the selection layer 10 is 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 comprises an IR absorber.

[0065] For the IR absorber in the selection layer, for example, inorganic, organometallic or organic pigments or dyes are used. The absorber layer is preferably printed on during production of the film element. The IR absorber is then present in particular in the form of pigment particles or a dye embedded in a printing ink. Suitable inorganic pigments can be, 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 include phthalocyanines or naphthalocyanines. Suitable organic compounds include CuH2Pc or porphyrins.

[0066] The structure of the value document 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 occurs in particular from a side 12 of the carrier element 2 facing away from the film element 4.

[0067] The luminescence marker 5 emits the luminescence radiation 6 upon excitation. The luminescence radiation 6, in turn, propagates within the carrier element 2 and at least partially impinges upon the selection layer 10. Only a portion of the spectrum is allowed to pass unhindered through the selection layer 10, or the entire spectral range of the luminescence radiation 6 may even be inhibited, preferably to varying degrees in intensity. The luminescence radiation 6 that 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.

[0068] The luminescence radiation, at least partially inhibited by the selection layer 10 or whose spectral intensity has been altered, now strikes 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. After passing through the selection layer 10, the luminescence radiation 6 passes through 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 detection, for example, a detector is arranged on the opposite side 12.

[0069] It may be that during the detection of the reflected luminescence signal or the reflected luminescence radiation 6, not only reflected luminescence radiation is detected, but also a portion of directly emitted luminescence radiation is combined.

[0070] According to the exemplary embodiment, the foil element 4 is designed as a layered security element. This security element is characterized by the fact that it is difficult to replicate without special manufacturing equipment and specialized manufacturing expertise. The foil element is preferably designed as a hologram and / or security thread and / or security strip.

[0071] According to the embodiment, the film element 4 is arranged on a surface 13.

[0072] According to the exemplary embodiment, the reflection layer 9 and the selection layer 10 are formed to overlap at least in some areas when viewed perpendicular to the carrier element 2. For example, the reflection layer 9 and the selection layer 10 are formed to completely overlap. For example, the reflection layer 9 and the selection layer 10 are formed in register with one another.

[0073] The reflection layer 9 has a reflection spectral range 14. The selection layer 10 has a selection spectral range 15. According to the exemplary embodiment, the reflection spectral range 14 is designed to be broader in bandwidth than the selection spectral range 15. This means that the reflection spectral range 14 or the reflection layer 9 reflects a larger wavelength range than the selection spectral range 15 or the selection layer 10 inhibits. This is advantageous because it also allows the use of broadband reflecting metal layers for the reflection layer, which can simultaneously provide other functions of the film element, such as a reflection hologram.

[0074] Fig. 2 shows the value document 1 analogous to Fig. 1 However, according to this embodiment, the luminescent marker 5 is arranged on the opposite side 12 of the carrier element 2. Thus, the luminescent marker 5 can, for example, be printed or applied to the back of the carrier element 2 as a coating.

[0075] In addition, the luminescence marker 5 can also be incorporated into the carrier element 2, as shown in Fig. 1 shown, embedded.

[0076] Fig. 3 shows the value document 1 also analogous to Fig. 1 According to the embodiment of Fig. 3 However, the film element 4 is embedded in the carrier element 2. This means, for example, that there is a recess 16 in the carrier element 2, into which the film element 4 is introduced, embedded or integrated. It may be that the film element 4 is incorporated into the carrier element 2 during production. For example, the film element 4 can be surrounded by the carrier element 2 only on one side or completely on all sides by the carrier element 2. This is particularly the case when the film element 4 is designed as a fully embedded security thread or only in some areas of a security thread that is partially embedded as a so-called window thread.

[0077] The luminescence marker 5 is according to the embodiment of Fig. 3 arranged in the carrier element 2. However, it may also be that the luminescence marker 5 in the embodiment of Fig. 3 only outside the support element 2, for example as in Fig. 2 shown, is arranged on the carrier element 2. Furthermore, it is also possible for the luminescence marker to be embedded in the carrier element 2 and at the same time applied to an outer side of the carrier element 2.

[0078] Fig. 4 shows a further embodiment of the value document 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. In addition, the luminescence marker 5 can also be formed in the carrier element 2.

[0079] Fig. 5 shows an embodiment of a method for classifying the value document 1. It shows an excitation unit 17, which excites the luminescence marker 5 with excitation radiation 26, for example, light. After the excitation process, the excited luminescence marker 5 emits the luminescence radiation 6. According to the embodiment, the luminescence radiation 6 is emitted at least at the first wavelength 7 and the second wavelength 8.

[0080] At least a portion of the luminescence radiation 6 strikes the selection layer 10 present and not shown in the figure, where it is at least partially spectrally inhibited, i.e. intensities of selected wavelengths of the luminescence radiation 6 are reduced or exit the selection layer 10 with less intensity than enter the selection layer 10. After the selection layer 10, the luminescence radiation 6, which has been at least partially inhibited or altered with regard to spectral intensities, strikes the reflection layer 9 and is reflected from there back to the selection layer 10, i.e. reflected, penetrates the selection layer 10 again, now also penetrates the carrier element 2 and is finally detected outside the carrier element 2, on the opposite side 12 of the carrier element 2, by a detection unit 18. The detection unit 18 is designed, for example, as a spectrometer and / or has at least two detection units.Preferably, a first detection unit is 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 value document 1 is preferably smaller than the extent of the film element 4. The first detection unit and the second detection unit preferably have substantially the same detection area.

[0081] Fig. 6 shows a schematic representation of an embodiment of the method in which excitation radiation 26 is emitted in the direction of the carrier element 2 to excite the luminescence marker 5. The excitation radiation 26 preferably has only a single wavelength. After excitation of the luminescence marker 5, the excitation radiation 26 continues to radiate at reduced intensity, penetrating the selection layer 10 in the exemplary embodiment, and striking the reflection layer 9. The excitation radiation 26 is reflected by the reflection layer 9, radiated again through the selection layer 10, and strikes the luminescence marker 5 again to excite it again at reduced intensity. After renewed excitation, the excitation radiation 26 then leaves the carrier element 2 with further reduced intensity at the side 12 facing away from the film element 4.

[0082] Furthermore, the first wavelength 7 of the luminescence radiation 6 is shown, which, after 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 essentially uninhibited. Subsequently, the first wavelength 7 is reflected by the reflection layer 9 and again penetrates the selection layer 10 essentially uninhibited. 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.

[0083] However, the first wavelength 7 is radiated in a non-directional manner, which is why the first wavelength 7 exits the carrier element unhindered at the opposite side 12 even without passing through the selection layer 10.

[0084] In addition, the second wavelength 8 is also shown, which is also emitted after 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. According to the exemplary embodiment, the selection layer 10 is designed to inhibit the second wavelength 8, i.e. the second wavelength 8 leaves the selection layer 10 attenuated 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, wherein the second wavelength 8 is further attenuated as it passes through the selection layer 10 again. Subsequently, the second wavelength 8 penetrates the carrier element 2 and leaves it on the opposite side 12.

[0085] The second wavelength 8 is also emitted in a particularly undirected manner, which is why the second wavelength 8 exits the carrier element unhindered at the opposite side 12 even without passing through the selection layer 10.

[0086] Fig. 7 shows an 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 location of the second wavelength 8. The dent 20 arises because the selection layer 10 inhibits the intensity of the second wavelength 8.

[0087] 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 reflection layer 9 is not present, and only the direct luminescence radiation of the luminescence marker 5 is detected, for example, outside of the partial area 3. The absorption-free curve 23 arises when the selection layer 10 is not present, thus eliminating selective inhibition, but the reflection layer 9 is present, for example, in the case of a counterfeit foil element. In the latter case, the dent 20 is then absent.

[0088] On an abscissa 24 of the diagrams according to Fig. 6 bis 11 The wavelength is plotted in nm. The signal strength is plotted on one ordinate 25 of the diagrams, for example, in units of the photocurrent of a photodiode.

[0089] Fig. 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 luminescence marker 5. The luminescence spectrum 27 can correspond to the standard curve 22 from Fig. 7 are equivalent to.

[0090] Fig. 9 shows a further 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.

[0091] Fig. 10 shows a further 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.

[0092] Fig. 11 shows a further 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.

[0093] In a further embodiment, a value document 1 is produced. A paper carrier element 2 is provided over its entire surface with a luminescent marker 5 consisting of two luminescent substances, both of which can be excited at the same wavelength or the same excitation radiation 26. The first luminescent substance emits luminescent radiation 6 at 1100 nm – corresponding to the first wavelength 7 – and the second luminescent substance emits luminescent radiation at 1600 nm – corresponding to the second wavelength 8. A security stripe is additionally applied to this carrier element 2 on the front side 13 in a partial area 3 as a film element 4. The security stripe has a visual level 1 feature consisting of a microlens structure with an underlying printed white ink layer. The white ink layer simultaneously serves as a reflective layer 9.In addition, the film element 4 has an IR absorber layer below the white ink layer as a selection layer 10. In this embodiment, the IR absorber layer consists of a security printing ink with broadly varying absorption, which has an absolute absorption of approximately 50% at 1100 nm and an absolute absorption of only 10% at 1600 nm. The structure of the security document corresponds to the . Fig. 1 , the spectral ratios of the Fig. 11 .

[0094] 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 impression forgery. The counterfeit foil element differs from the genuine foil element 4 in particular in that it lacks a selection layer 10.

[0095] For authenticity check according to Fig. 5 und Fig. 6 A sensor with remission geometry is used, which in particular has at least one excitation unit 17 and a detection unit 18. The value document 1 is transported past the sensor by a transport device, wherein the sensor takes at least one measurement of the luminescence radiation 6 in the partial area 3 and at least one further measurement of the luminescence radiation 6 outside the partial area 3. For this purpose, the value document 1 is illuminated with excitation radiation 26, which is designed to excite both luminescent substances of the luminescence marker 5 to emit luminescence. The luminescence radiation 6 emerging from the rear side 12 of the value document 1 is detected by the detection unit 18, wherein a first detection unit only detects the luminescence intensity at 1100 nm and a second detection unit only detects the luminescence intensity at 1600 nm.As seen from the sensor, behind the value document being transported there is a broadband absorbing surface, for example black.

[0096] 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 detected 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 during the measurement outside the partial area 3 or measured there (luminescence spectrum 27 in Fig. 11 ). In the present embodiment, this ratio is preferably 1.0.

[0097] In the measurements in sub-area 3, the measured luminescence 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 approximately 50% in the presence of a film element with a reflective layer 9.

[0098] If the film element has the IR absorber layer 10 characteristic of a genuine film element 4, the measured intensity at the first wavelength 7, in particular 1100 nm, is, however, due to the interaction with this selection layer, approximately 10% lower than at the second wavelength 8, in particular 1600 nm, which is particularly characteristic of the spectral signature 19. The authenticity of the film element 4 can thus be verified based on the measured ratio between the luminescence intensity at the first wavelength 7 and the luminescence intensity at the second wavelength 8. The difference between the intensity ratios outside of sub-area 3 and within sub-area 3 is used as the decision criterion.If the measured intensity ratio in sub-area 3 is, for example, more than 0.07 smaller than outside sub-area 3, the presence and authenticity of the foil element 4 is considered confirmed; otherwise, the checked value document 1 is rejected.

Claims

1. Valuable document (1) comprising a carrier element (2) and a film element (4) arranged in a partial region (3) of the carrier element (2), wherein the carrier element (2) has, at least in the partial region (3), a luminescence marker (5) designed to emit luminescence radiation (6) having at least a first wavelength (7) and a second wavelength (8) in each case in the infrared spectral range, characterized in that the film element (4) has a reflection layer (9) and a spectral selection layer (10), wherein the selection layer (10) is arranged between the carrier element (2) and the reflection layer (9), wherein the reflection layer (9) is configured to reflect infrared radiation, and the selection layer (10) is configured to spectrally selectively inhibit transmission of infrared radiation, wherein the inhibition of the transmission of the first wavelength (7) and the inhibition of the transition of the second wavelength (8) differ by at least 10%.

2. Valuable document (1) according to Claim 1, wherein the film element (4) is configured as a security element constructed in layered fashion.

3. Valuable document (1) according to Claim 1 or 2, wherein the film element (4) is configured as a patch and / or hologram and / or security thread and / or security strip.

4. Valuable document (1) according to any of the preceding claims, wherein the film element (4) is applied on a surface (13) of the carrier element (2).

5. Valuable document (1) according to any of the preceding claims, wherein the reflection layer (9) and the selection layer (10) are configured so as to overlap when viewed perpendicular to the carrier element (2).

6. Valuable document (1) according to any of the preceding claims, wherein the selection layer (10) is configured as an absorption layer.

7. Valuable document (1) according to any of the preceding claims, wherein the reflection layer (9) has a reflection spectral range (14), and the selection layer (10) has a selection spectral range (15), wherein the reflection spectral range (14) is more broadband than the selection spectral range (15).

8. Valuable document (1) according to any of the preceding claims, wherein the reflection layer (9) is designed to reflect at least 50% of a luminescence radiation (6) emitted by the luminescence marker (5) and incident on the reflection layer (9).

9. Valuable document (1) according to any of the preceding claims, wherein the luminescence marker (5) is embedded in the carrier element (2).

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

11. Method for classifying a valuable document (1) comprising a carrier element (2) having a luminescence marker (5), and comprising a film element (4) arranged in a partial region (3) of the carrier element (2) and comprising a reflection layer (9), in which method the following steps are carried out: a) exciting the luminescence marker (5) with radiation from an excitation side of the valuable document (1), wherein the excitation side is the side (12) of the valuable document (1) facing away from the film element (4) ; b) capturing an intensity of the infrared luminescence radiation (6) emitted by the excited luminescence marker (5) and reflected by the reflection layer (9); c) comparing the captured intensity with a reference intensity; and d) classifying the valuable document (1) on the basis of the comparison, wherein the luminescence radiation (6) emitted the excited luminescence marker (5) is spectrally inhibited by a selection layer (10) of the film element (4) before the capturing in step b).

12. Method according to Claim 11, 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 captured as the captured intensity.

13. Method according to either of Claims 11 and 12, wherein a direct luminescence intensity of the luminescence marker (5) outside the partial region (3) is captured on a direct propagation path, and in step d) the classifying is carried out on the basis of the direct luminescence intensity and the intensity captured in step b).

14. Method according to any of Claims 11 to 13, wherein the reference intensity is provided by a direct luminescence intensity of the luminescence marker (5) captured outside the partial region (3) and on a direct propagation path.

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