WO2004102490A1

WO2004102490A1 - Sensor for recognising the authenticity of a luminescent security element of a valuable document, valuable document and method for the production thereof

Info

Publication number: WO2004102490A1
Application number: PCT/EP2004/003461
Authority: WO
Inventors: Manfred Paeschke; Oliver Muth; Detlef Klepsch; Hermann Hecker; Arnim Franz-Burgholz
Original assignee: Bundesdruckerei Gmbh
Priority date: 2003-05-19
Filing date: 2004-04-01
Publication date: 2004-11-25
Also published as: DE10322794A1; DE10322794B4; EP1625552A1

Abstract

The invention relates to a sensor (1) for recognising the authenticity of a luminescent security element (2) of a valuable document (4). Said sensor comprises an emitter (6) which is used to produce a scanning signal comprising an excitation wavelength, and a radiation receiving device (12) which is used to detect a reply signal emitted by the safety element (2), said reply signal having a reply wavelength. The aim of the invention is to produce a sensor which has particularly high detectivity and precision in the examination of authenticity of the valuable document (4). As a result, the inventive emitter (6) is configured in such a manner that it can produce a scanning signal having an excitation wavelength of between, approximately, 940 nm - 990 nm and the radiation receiving device (12) in configured in such a manner that it can detect the reply signal having a reply wavelength of between, approximately 800 +/- 10 nm. The invention also relates to a valuable document (4) comprising at least one security element (2) equipped for recognising authenticity by means of said type of sensor (1). Said valuable document (4) comprises at least one marking layer (18) comprising luminescent anti-stroke pigments (20) which are disposed on an NIR transparent cover layer (22).

Description

description

Sensor for the authenticity detection of a luminescent security element of a value document, value document and method for producing a

value document

The invention relates to a sensor for the authenticity detection of a lumen-emitting security element of a value document, with an emitter for generating a scanning signal with an excitation wavelength, and with a radiation receiver for detecting a response signal emitted by the security element with a response wavelength. It further relates to a value document with at least one security element designed for authenticity detection by such a sensor, and to a method for producing such a value document.

To protect against counterfeiting or counterfeiting, value or security documents, such as banknotes, ID cards or chip cards, are provided with so-called security features or security elements which, for example in the case of paper-based value documents, are intended to reliably preclude imitation by making color copies. The security elements can in particular be designed as optically variable elements, such as holograms or interference layer elements, which convey different color impressions when viewed depending on the viewing angle, but are not transferred to the copy during the copying process. However, security elements of this type cannot be read out or evaluated by machine, or can only be carried out with difficulty, so that an automated security check of the respective value documents is only possible to a limited extent and with high technical outlay.

Especially when designing a value document as a data carrier, such as an identification card, credit card, passport, driver's license or the like, in addition to a visually recognizable authenticity check, the possibility of a machine authenticity check with high security against forgery is of particular importance. For this purpose it is, for example, from DE 101 13 266 A1 and from DE 101 13 267 A1 it is known to use luminescent anti-Stokes pigments in a security element of a document of value.

When using such anti-Stokes pigments, a suitable sensor is used to irradiate a scanning signal generated by an emitter, in particular a laser, into the marking area in which the anti-Stokes pigments are kept. In response to the irradiated scanning signal, the anti-Stokes pigments in the so-called “up-conversion mode” emit a response signal with a shorter response wavelength than the excitation wavelength, which is recorded in a suitably designed radiation receiver. The excitability of the Anti-Stokes pigments depends on the irradiated excitation wavelength, the response wavelength emitted also being characteristic of the material properties of the anti-Stokes pigment used, in particular of its activator and codotation with regard to the host lattice used Response wavelength compared to the irradiated excitation wavelength, possibly with additional evaluation of the signal shape of the emitted response signal, is therefore a comparatively reliable assignment of the signature of the response signal to signatures expected for certain anti-Stokes pigments If the detected signature matches an expected signature, the expected presence of a certain group of anti-Stokes pigments and thus the authenticity of the value document provided with such a luminescent security mark can thus be concluded.

The sensors known from EP 1170707 A2 and EP 1160719 A2 are particularly suitable for use in the detection of authenticity of documents of value with such luminescent security elements. Such sensors include an emitter for generating the scanning signal and a radiation receiver for detecting the response signal and can be designed to be static, stationary or mobile as a hand sensor.

The invention is based on the object of developing a sensor of the type mentioned above in such a way that a particularly high detection sensitivity and accuracy can be achieved in the authenticity check of the value document. Furthermore, one should a value document that is particularly suitable for authenticity detection by such a sensor and a method for producing the value document can be specified.

With regard to the sensor, this object is achieved according to the invention in that the emitter is designed to generate the scanning signal with an excitation wavelength of approximately 940 nm to 990 nm and the radiation receiver is designed to detect the response signal with a response wavelength of approximately 800 +/- 10 nm.

The invention is based on the consideration that for a particularly high detection sensitivity, the evaluation of the luminescent properties of the security element should be specifically aimed at a particularly high signal intensity of the anti-Stokes pigments that can be achieved. Particularly with regard to the type classes of anti-Stokes pigments that are particularly suitable for use in documents of value, it has surprisingly been found that the actually invisible anti-Stokes band located in the near infrared (NIR) range is particularly high , has about 100 to 500 times the luminescence intensity compared to the emission in the visible range. By using this anti-Stokes luminescence in a targeted manner, a signal intensity that can be easily and reliably evaluated by machine can therefore be achieved even with relatively small admixtures of the anti-Stokes pigments in the marking area of a value document. The sensor is therefore specifically designed to evaluate this NIR luminescence.

As has furthermore surprisingly been found, a targeted variation of the activator concentration and the codoping concentration in the anti-Stokes pigment can influence the response and decay time behavior of the respective luminescence. An evaluation of the response and decay time behavior of the luminescence enables an even more detailed conclusion to be drawn about the exact composition of the anti-Stokes pigments used. In order to make this also usable for the authenticity check in the sense of a large number of different types of pigment that are conceivable, the radiation receiver of the sensor is advantageously designed to detect a response time and / or a decay time. The sensor is advantageously integrated in a stationary card reader or is designed as a mobile and / or body-worn reader.

With regard to the document of value, the stated object is achieved in that the security element of the document of value comprises in a marking area a marking layer comprising luminescent anti-Stokes phosphor, which is covered by an NIR-transparent cover layer. The anti-Stokes phosphor is preferably in the form of anti-Stokes pigments.

It is provided that the document of value in its entirety is specifically aligned for common use with the sensor for authenticity detection. There should therefore be a marking layer which comprises anti-Stokes pigments which can be excited by the excitation wavelength of the sensor and which emit in the luminescence response with the intended response wavelength. In order to protect the anti-Stokes pigments held in the marking layer for high document security but also against external influences and in particular against manipulation, the marking layer should be covered by a cover layer in the manner of a hidden, encapsulated or protected version. The targeted evaluation of the luminescence phenomena in the NIR range remains unimpeded by the cover layer for radiation in the near infrared range, ie. H. is kept transparent, in particular for wavelengths of more than 780 nm and less than 1200 nm.

In a particularly advantageous embodiment, the NIR-transparent cover layer is designed as a print layer, as a film or as an opaque layer. In an alternative advantageous embodiment, the NIR-transparent cover layer is designed as an opaque substrate with a thickness of more than 20 μm, preferably more than 50 μm.

In a particularly advantageous embodiment, particularly fine-grained security pigments that can be processed in all known security printing techniques and adhesion promoter layers as well as in paper bodies and plastic films are used as anti-Stokes pigments. For this purpose, the anti-Stokes phosphor is advantageously in the form of a rare earth-activated, preferably thulium-activated and ytterbium-codotized ten host lattice. In particular, gadolinium oxysulfide (GdO ₂ S), yttrium oxysulfide (YO ₂ S), lanthanum oxysulfide (LaO ₂ S) and / or lutetium oxysulfide (LuO ₂ S) can be considered as the host lattice or matrix material. Anti-Stokes pigments of this type can be added to a single printing ink in a visible motif in a very small filling quantity, and can also be carried out as independent, invisible machine-readable printing features, such as bar codes or 2D codes or symbols, diagrams, patterns or letter numbers Combinations for, for example, an OCR reader and similar reading devices.

The anti-Stokes pigments mentioned also have anti-Stokes bands in the visually visible range, in particular between 460 and 490 nm and between 630 and 670 nm and between 680 and 720 nm, which are, however, considerably less intensive than those for evaluation now Anti-Stokes luminescence envisaged in the NIR range. The security features created with such anti-Stokes pigments can be used in a very fine grain size distribution of a few micrometers in size and, depending on the degree of filling, are invisible to whitish in preferably internal printed structures. Particularly when the emission in the visible wavelength range is not used in the authenticity check, such an anti-Stokes pigment can also be used internally in documents, it being only necessary to ensure that the surrounding layers are NIR-transparent for evaluation. Such anti-Stokes pigments can thus be arranged on the document of value completely invisible to the human eye in terms of printing technology or in terms of area or even the entire area.

In order to enable a high readout speed in the authenticity check and, on the other hand, to ensure a authenticity check differentiated according to different pigments by specifically adjusting the decay or decay behavior, the anti-Stokes pigment advantageously has a ytterbium content of 0.05 <x <0. 80, preferably 0.20 <x <0.60, and a rare earth content of 0.0001 <y <0.10, preferably 0.0001 <y <0.05. Additional cations and / or anions can also be built into the host lattice in order to influence the anti-Stokes pigment's decay and decay characteristics. By a suitable choice of Concentrations can be achieved in particular that the decay time can be set in a range from 1 to 200 μs and in particular from 10 to 50 μs.

In a particularly advantageous embodiment, the document of value is particularly suitable for printing production processes. In order to enable the anti-Stokes pigment to be incorporated into the security element in a particularly simple manner, preferably using a conventional printing process, the anti-Stokes pigment advantageously has an average particle size of less than 5 μm, in a particularly advantageous embodiment less than 3 μm, in particular less than 2 μm. The anti-Stokes pigments are advantageously incorporated in the form of small inorganic particles in a printing ink, the degree of filling being in the range from 1 to 30 percent by weight, advantageously in the range from 1 to 20 percent by weight and preferably in the range from 5 to 10 percent by weight is selected so that the graphic and in particular color design is not disrupted.

The document of value can in particular be designed in the manner of a data carrier as a so-called ID card, passport, visa, driver's license, credit card, postage stamp, coupon, general stamp, banknote or the like, with a high degree of reliability being a authenticity check at speeds of up to 10 m / s is feasible. The security element with the luminescent anti-Stokes pigments is furthermore in a particularly advantageous embodiment in a form invisible to the human eye as machine-readable coding in the form of individual or constant codes in the form of bar codes, 2-D codes, number Number symbol elements or the like are attached in the data carrier, the authenticity detection being carried out with the sensor and its evaluation unit in such a way that the code by means of a secret algorithm arranged in the evaluation unit in the form of a software module or also preferably in the form of a electronic component and / or in an external evaluation unit in connection with another information element on the data carrier can be verified for authenticity, information elements such as magnetic strips, bar codes, EAN codes and the like printing codes or also contact and / or contactless chip cards or RFID elements in the form of ROM-S memory elements with unique IC serial numbers from For example, some 10 bit to 128 bit length are secured against counterfeiting and / or copying.

As has been found, the luminescence provided for evaluation in the NIR range can be used in a particularly favorable manner by laminating the marking layer comprising the luminescent anti-Stokes pigments into a surrounding layer system. The value document therefore advantageously comprises a carrier body which is designed as a base body for the formation of a value or ID card into which the marking layer is laminated. The marking layer is advantageously covered by a plurality of NIR-transparent cover layers to form a laminate body.

The marking layer is advantageously formed by an extruded or injection-molded plastic body in which the anti-Stokes pigments are embedded in a matrix. At least one, preferably both, surfaces of the substrate or the core layer comprising the marking layer can be provided with a graphic design and optionally with an upper cover laminate and / or a lower cover laminate.

With regard to the method for producing the value document, the stated object is achieved by the marking layer using a coating method such as brushing, spraying, spraying, coating, dipping, but preferably using a printing method, preferably using screen printing, intaglio printing, offset printing, statistical printing, screen printing or letterpress printing, is applied to the carrier body. This enables a comparatively simple production of the value document equipped with the security element, and in addition a particularly high degree of flexibility can be achieved with a possibly desired graphic design of the marking layer, for example as a printed image. Screen gravure processes, steel gravure printing processes, flexographic printing processes, digital printing processes in the form of inkjet printing processes and / or liquid and solid toner processes or also the application via the adhesive layer of a thermal transfer and / or thermal sublimation tape are also suitable. A particularly simple processability can be achieved by advantageously when applying the marking layer a printing ink is used which contains a solvent and / or a binder in addition to the anti-Stokes pigments.

To further increase the security function of the security element, the specifications of a lateral structure can be provided in the marking layer, so that when analyzing the luminescence phenomena, a distinction can be made between active and inactive areas in a spatially resolved manner. In order to make this possible, radiation absorbers are advantageously generated in lateral partial areas of the marking layer by selective irradiation with a laser, preferably with an NDΥAG laser with a wavelength of 1064 nm. The laser radiation can in particular produce soot particles that absorb the emission radiation from the anti-Stokes phosphors, so that no emission from the outside is registered in these areas.

The advantages achieved by the invention are, in particular, that a particularly high signal intensity can be achieved through the targeted use of the luminescence phenomena of the anti-Stokes pigments in the NIR range, so that the pigments can be reliably identified during the authenticity check even with only comparatively low pigment concentrations can be reached in the marking layer. The luminescence security feature is also largely invisible in the visible wavelength range, but can be activated and verified by means of infrared radiation, so that the authenticity check is particularly suitable for machine evaluation. Due to the hidden arrangement of the security element, a replica of the security element is therefore not conceivable or only at all with considerable effort. The targeted influencing of the response and decay behavior of the anti-Stokes luminescence also makes it possible to increase the available variety of anti-Stokes pigments very greatly, so that replication or counterfeiting are made considerably more difficult.

An embodiment of the invention is explained in more detail with reference to a drawing. In it show: FIG. 1 shows schematically a sensor for the authenticity detection of a luminescent security element in an assigned value document,

FIG. 2 shows an alternative embodiment of the value document according to FIG. 1,

FIGS. 3 to 6 schematically each show the structure of further alternative embodiments of the value document according to FIGS. 1 and

Figure 7 shows the document of value according to Figure 1 in supervision.

Identical parts are provided with the same reference symbols in all figures.

The sensor 1 shown only schematically in FIG. 1 is designed for the authenticity detection of a luminescent security element 2 of an assigned value document 4. The sensor 1 can be configured as a stationary or also portable sensor and, in particular with regard to its functional components, can be configured the same or similar to the sensors known from the publications EP 1160719 A2 and EP 1170707 A2, the disclosure content of which is hereby fully incorporated , As essential functional components, the sensor 1 according to FIG. 1 comprises an emitter 6 for generating a scanning signal symbolized by the arrow 8 and a radiation receiver 12 designed for detecting a response signal symbolized by the arrow 10 and emitted by the security element 2.

In a marking area 14, the security element 2 of the value document 4 comprises a marking layer 18 which is applied to a carrier body 16 and which comprises active luminescent anti-Stokes pigments 20 for checking the authenticity. The marking layer 18 is covered by a cover layer 22.

For the purpose of checking the authenticity, the emitter 6 of the sensor 1 radiates a scanning signal with a predetermined excitation wavelength into the marking layer 18 comprising the anti-Stokes pigments 20. The anti- Stokes pigments 20 excited to luminescence and emit a response signal by means of up-conversion, the response wavelength of which is smaller than the excitation wavelength. The radiation receiver 12 detects the emitted response signal, and in particular a time-resolved evaluation can also be provided. Based on the characteristics of the response signal, in particular on the basis of a comparison of the response wavelength with the emitted excitation wavelength and possibly an analysis of the signal shape, the evaluation enables the type and possibly also number of anti-Stokes pigments 20 in the marking layer 18 to be inferred. It can thus be recognized whether an expected type of anti-Stokes pigment 20 is present in the marking layer 18, in which case the authenticity of the value document 4 is recognized.

The sensor 1 and the value document 4 to be used with it are designed for particularly high reliability in the authenticity check with comparatively simple means. For this purpose, provision is made for both the excitation of the luminescence and the evaluation of the luminescence in wavelength ranges in the NIR (near infrared). To make this possible, the emitter 6 is designed to generate the scanning signal with an excitation wavelength of approximately 940 nm to 990 nm and the radiation receiver 12 is designed to detect the response signal with a response wavelength of approximately 800 +/- 10 nm. The adaptation of the radiation receiver in particular can be made possible or facilitated by the selection of suitable detectors and / or, if necessary, by specifying suitable optics in the beam path.

In order to enable the consistent use of the luminescent in the NIR range provided in the exemplary embodiment, but on the other hand also to ensure reliable protection of the marking layer 18 against impairments or mechanical damage, the cover layer 22 is provided, which is designed to be NIR transparent by a suitable choice of material ,

The security feature 2 can be applied to the carrier body 16 over the entire surface or in a graphically designed manner. Alternatively, the marking layer 18 with the embedded anti-Stokes pigments 20 in the form of a polymer matrix can also be used to promote adhesion can be used for the top layer 22, wherein a graphic design (not shown) can also be arranged under or on the marking layer 18. The carrier body 16 can be formed in particular from plastic or from paper.

The anti-Stokes pigments 20 are based on a thulium (Tm) -activated and ytterbium (Yb) -codotated host lattice, with gadolinium oxysulfide (Gd ₂ O ₂ S), yttrium oxysulfide (Y ₂ O ₂ S) as host lattice, Lanthanum oxysulfide (La ₂ O ₂ S) and / or lutetium oxysulfide (Lu ₂ O ₂ S) can be used. The anti-Stokes pigment 20 is thus via the formula (Gdι _-x .yYbχTm _y ) ₂ O ₂ S or (Gdι.χ.y) ₂ θ ₂ S: YbχTm _yι (Yι _-x- yYbχTmy) ₂ θ ₂ S or (Y _1-xy ) ₂ O ₂ S: YbχTmy _t (Laι _-x . _y YbχTm _y ) ₂ θ ₂ S or (Laι _-X- _y ) ₂ O ₂ S: YbχTm _y , (Luι _-x- yYb _x Tm _y ) ₂ O ₂ S or (Lu-ι _-xy ) ₂ OS: Yb _x Tm _y writable, with concentration values of 0.20 <x ≤ 0.60 for being used to set a response and decay behavior that can be evaluated in detail in the luminescence the ytterbium portion and 0.001 <y ≤ 0.05 for the thulium portion.

The anti-Stokes pigments 20 are arranged in a matrix-like manner in the marking layer 18. It was used here that the anti-Stokes pigments 20 can be produced with comparatively small average particle diameters of, for example, less than 2 μm and without a reduction in the response intensity at comparatively high temperatures of up to 200 or 300 ° C. in the marking layer 18 can be integrated, whereby a polymer matrix can be produced and extrusion, thin film casting, calendering or injection molding can be used. The anti-Stokes pigments 20 are also very chemically resistant, so that they could also be incorporated into a paper matrix, such opaque paper substrates having anti-Stokes pigments 20 arranged in a matrix and / or with a graphically arranged arrangement or in the form of strips , Points or generally recurring patterns and can be used for authenticity detection.

In the exemplary embodiment according to FIG. 2, a particularly simple technical embodiment of the value document 4 is shown schematically. A paper or plastic substrate or another substrate customary in the security industry is used as the carrier body 16. The flat and / or graphically designed security element element 2 is applied by means of printing processes customary in the graphics industry, but can also be laminated on or embossed or otherwise applied in the form of a flat layer-like element. The cover layer 22 may now be arranged above this in the form of a graphic design. In the exemplary embodiment according to FIG. 2, both the carrier body 16 and the cover layer 22 provided in the form of a graphic design are transparent in the NIR wavelength range, so that an undisturbed authenticity check via the anti-Stokes pigments 20 contained in the marking layer 18 by using the sensor 1 is possible. For example, a clear verification could be carried out using conventional opaque white papers with a grammage of 70 to 120 per square meter.

In Figure 3, the individual layers of a document of value 4 are shown as separate segments. In this exemplary embodiment shown in cross section, document of value 4 has the structure of a laminate-like composite of several layers. The marking layer 18 comprising the electroluminescent pigments 20 or anti-Stokes phosphors is part of a substrate which, owing to its comparatively massive design, also forms the carrier body 2. This substrate can be provided on both sides with a graphic design 30, for example a printed image or pattern, the respective graphic design 30 in turn being covered with an upper or lower cover laminate 32. The cover laminates 32 and the graphic designs 30 are designed to be NIR-transparent to form the respective cover layer 22.

The value document 4 executed according to the exemplary embodiment according to FIG. 3 can be used, for example, as a simple ID card or as an insert in a passport and the like, wherein the carrier body 2 comprising the marking layer 18 can be a plastic substrate or also a paper substrate. The cover laminates 32 can be, for example, thin PET films with internal diffractive diffraction structures and a corresponding adhesion-promoting layer, wherein the cover laminates 32 can be micro-perforated to further increase the security against forgery. To further increase the safety standard, a coding can be written in the marking layer 18 or in the film 30 by means of an NDΥAG laser beam with a 1064 nm wavelength, with laterally selective irradiation of the ND: YAG laser beam lateral partial areas of the marking layer 18 are deactivated, so that a lateral structure, which can also be used as a security feature, is produced with regard to the luminescent properties.

In the exemplary embodiment according to FIG. 4, the value document 4 is designed as a data carrier in which the electroluminescent pigments 20 are arranged in a matrix-like arrangement in the adhesive layer 34 of a transparent hologram 36. In this embodiment, the hologram 36 thus serves as a cover layer 22 for the marking layer 18 formed by the adhesion-promoting layer 34. The hologram 36 is therefore transparent in the NIR wavelength range, so that a verification of the luminescence properties can be carried out by appropriate irradiation from above. Alternatively, the carrier body 2, which is in the form of a substrate, can also be NIR-transparent, so that the verification can be carried out by irradiation from below. The hologram 36 designates diffractive diffraction structures in the corresponding layer component.

In the likewise explosive representation of the exemplary embodiment according to FIG. 5, the value document 4 is designed as a typical ID document on the basis of two interconnected paper substrates 38 which are interconnected by means of an adhesion promoter layer 40. The adhesion promoter layer 40 serves as a marking layer 18, the electroluminescent anti-Stokes pigments 20 being integrated in the adhesion promoter layer 40. The paper substrates 38 are each provided with a graphic design 42 on their respective outside, for example with a printed image. The anti-Stokes pigments 20 can be incorporated into the adhesion promoter layer 40 uniformly in a matrix-like or graphically designed manner, with a coding design in particular also being possible. In a further embodiment, the graphic design 42 can be provided with further transparent protective layers. Conventional graphic printing techniques or rolls can be coated, curtains poured, sprayed and lidded, and similar coating technologies can be used.

In the exemplary embodiment according to FIG. 6, the value document 4 is also designed as a typical ID document based on two interconnected paper substrates 38. which are connected to one another with an adhesion promoter layer 40, the anti-Stokes pigments 20 being integrated into the adhesion promoter layer 40. In this embodiment too, the paper substrates 38 are each provided with a graphic design 42 on their respective outer sides. For further protection against external effects and mechanical damage is the one thus formed

Layer composite with a comprehensive transparent cover laminate 44 surrounded. The cover laminate 44 is kept transparent, in particular in the NIR wavelength range. A PET film, a PETG film or else a PVC, PC, PMMA or similar transparent polymer film of a typical thickness of, for example, 10 to 100 μm can preferably be used as the cover laminate 44. The foils can be provided with defractive diffraction structures on the inside, it also being ensured with these diffraction structures that there is transparency in the NIR wavelength range. The cover laminate 44 can additionally be provided with a microperforation to further increase the security against forgery.

In the exemplary embodiment according to FIG. 7, the value document 4 in the form of a value card is shown in supervision. The value document 4 is basically designed according to the regulations of the ISO / IEC 7810 standard. The value document comprises 4 areas 50, 52 which are kept NIR-transparent and possibly also optically transparent. The areas 50, 52 are therefore particularly suitable for receiving a marking layer with the electroluminescent pigments 20 in accordance with the present concept. The upper edge 54 of the area 50 is arranged at a distance of at least 21 mm from the upper edge 56 of the value document 4, the lower edge 58 of the area 50 being at least 33 mm from the upper edge 56. The area 52 directly adjoins the lower edge 58, its lower edge 60 being at least 44 mm away from the upper edge 56. The side edges 62 of the area 52 are each arranged at least 20 mm from the corresponding side edge 64 of the value document 4. LIST OF REFERENCE NUMBERS

sensor

security element

value document

Emitter, 10 arrow 2 radiation receiver

Marking area 6 carrier body 8 marking layer 0 anti-Stokes pigments

Top layer graphic design of top or bottom top laminate

Bonding layer

Transparent hologram

paper substrate

Adhesion promoter layer graphic design

Cover laminate, 52 NIR-transparent area upper edge

Top edge, 60 bottom edge, 64 side edge

Claims

Expectations

1. Sensor (1) for the authenticity detection of a luminescent security element (2) of a value document (4), with an emitter (6) for generating a scanning signal with an excitation wavelength, and with a radiation receiver (12) for detecting one of the security element (2) emitted response signal with a response wavelength,

characterized in that

the emitter (6) is designed to generate the scanning signal with an excitation wavelength of approximately 940 nm to 990 nm and the radiation receiver (12) is designed to detect the response signal with a response wavelength of approximately 800 +/- 10 nm.

2. Sensor (1) according to claim 1, wherein the radiation receiver (12) is designed to detect a response time and / or a decay time of the response signal.

3. Sensor (1) according to claim 1 or 2, which is integrated in a fixed card reader.

4. Sensor (1) according to claim 1 or 2, which is designed as a mobile and / or body-worn reading device.

5. document of value (4) with at least one security element (6) designed for authenticity detection by a sensor (1) according to one of claims 1 to 4,

characterized in that

the security element (6) comprises, in a marking area (14), a marking layer (18) comprising a luminescent anti-Stokes phosphor (20) which is applied to a carrier body (16) and is covered by an NIR-transparent cover layer (22) ,

6. document of value (4) according to claim 5, wherein the NIR-transparent cover layer is designed as a printing layer, as an adhesive layer, as a film or as a transparent and / or opaque layer.

7. document of value (4) according to claim 5 or 6, wherein the NIR-transparent cover layer (50, 52) is designed as an opaque substrate with a thickness of more than 20 microns, preferably more than 50 microns.

8. document of value (4) according to one of claims 5 to 7, wherein the anti-Stokes phosphor is a rare earth- _activated lanthanoid _{oxysulfide of} the formula (LNι _-xy ) ₂ O ₂ S

: Yb _x SE _y with LN = La, Lu, Gd, Y and SE = Tm, Er, Ho.

9. document of value (4) according to claim 8, wherein the anti-Stokes phosphor has a ytterbium content of 0.05 <x <0.80, preferably 0.20 <x <0.60, and a rare earth content of 0.0001 <y <0.10, preferably 0.0001 <y <0.05.

10. document of value (4) according to any one of claims 5 to 9, wherein the anti-Stokes phosphor is in the form of anti-Stokes pigments (20) which have an average particle size of less than 5 microns, preferably less than 3 μm, in particular less than 2 μm.

11. Value document (4) according to one of claims 5 to 10, the carrier body is designed as a base body for the formation of a value or ID card, in which the marking layer (18) is laminated.

12. document of value (4) according to claim 11, the marking layer (18) is covered by a plurality of NIR-transparent cover layers to form a laminate body.

13. document of value (4) according to claim 11 or 12, the marking layer (18) of an extruded, calendered, injection-molded or film-cast art is formed body in which the anti-Stokes pigments (20) are embedded in a matrix.

14. A method for producing a value document (4) according to one of claims 5 s to 13, in which the marking layer (18) is applied to the carrier body (16) by means of a printing process, preferably by means of screen printing, intaglio printing, offset printing or letter set printing.

15. The method according to claim 14, in which a printing ink is used in the application of the marking layer (18) in which, in addition to the anti-Stokes pigments

(20) a solvent and / or a binder is included.

16. The method according to claim 14 or 15, in which radiation absorbers are generated in lateral partial regions of the marking layer (18) by selective irradiation with a laser, preferably with an Nd: YAG laser with a wavelength of 1064 nm.