EP0980763A1 - Security document with light-active dyes for authenticity verification - Google Patents

Abstract

The document contains an optically excitable color (3) used to detect a defined emission spectrum for the document and provides a characteristic spectrum for the document. The spectrum is characteristic for the color embedded in the document and for the material of the document. The color is directly applied on or in the document or is embedded in it. The document has a color (3) embedded in a carrier material (4) to form a laser active element. Colors used for different valuable and security documents have different emission properties providing reliable differentiation of different documents. Alternatively the color is embedded in a resonator or pigment platelet consisting of a carrier layer coated on both sides by reflective coating.

Description

The invention relates to a value and security document according to the preamble of claim 1.

The invention is based on a prior art, such as in the US 4,738,901. There is a value and security document in Form of copy-protected paper is provided, in which phosphor particles are embedded. It is a copy protection, because with that Copier-associated lasers excite the phosphor particles and those of Radiation emitted by the phosphor particles is emitted by a second detector added, which accordingly tells the copier that it is a protected document. An authenticity check of such a value and Security document is not provided for in this copy protection process and not possible.

The object of the present invention is to carry out an authenticity check of value and To propose security documents with optically stimulable dyes which is a defined emission spectrum of the optically excited value and Security document can be recorded and therefore a characteristic spectrum for this value and security document which is characteristic of both in the Security document embedded dye as well as for the material of the Security document itself.

This object is achieved by the characterizing features of patent claim 1 solved.

The present invention is based on the fact that the introduction of certain optically stimulable dyes in a security document so that the optical excitation of the value and security document in the value and Security document embedded dyes in resonance with the material of the Value and security document to get a sharply defined To emit spectrum of all excited materials.

So there will be a resonance between the material of the value and Security document and the dyes embedded there creates what to leads to a precisely specified emission spectrum, which on the one hand from depends on the material of the document and on the other hand on the embedded dyes.

The integration of exclusively developed laser dyes with preferably not commercial excitation wavelengths (UV to IR) in safety and Valuable products can be made in different ways. In principle there is one Incorporation into the substrate (e.g. paper, plastic films), in paper additives (e.g. fibers, planchettes), in printing inks and in production technology Combination with other security features (e.g. fluorescent, EL, up-conversion or phosphorescent pigments, metallized plastic strips, Holograms) possible. For introducing the liquid dye molecules into a solid matrix (granules with a size in the µm to nm range) and / or Protection of the dyes against UV light, solvents or other reagents is a suitable one depending on the application, e.g. UV-absorbing protective cover necessary. In the best case, the laser dyes can be directly in one Color component (resins or pigments) can be integrated. For applications in Card / film area can contain the unencapsulated or encapsulated dyes are stirred directly into the polymer matrix and fixed. Under the term Laser dye is understood to be a very high excitable by laser beam efficiently fluorescent material in any physical state, d. H. firmly liquid or gaseous.

scharfen Emissionspeaks" stellen sich erfindungsgemäß nur dann ein, wenn die verwendeten laseranregbaren Fluoreszenzstoffe in einen optischen Resonator eingebunden sind. Nur durch diese Resonanzerzeugung ergeben sich die scharfen Emissionspeaks, die dann sowohl charakteristisch für die Geometrie und optischen Eigenschaften des verwendeten Resonators als auch für die verwendeten Fluoreszenzstoffe sind.One advantage of laser dyes compared to fluorescent substances is the sharp emission peaks at defined emission wavelengths over the entire fluorescence range of the laser dyes. The

According to the invention, sharp emission peaks only occur if the laser-excitable fluorescent substances used are incorporated into an optical resonator. Only through this resonance generation do the sharp emission peaks result, which are then characteristic both of the geometry and optical properties of the resonator used and of the ones used Are fluorescent substances.

In addition to introducing the laser dyes into a resonator, one is resonator-free introduction of the dyes at the expense of the emission intensities in Valuable and security documents possible.

The emission intensity can be reduced by installing the laser dyes in one Increase the resonator. For this purpose, the laser dye is coated on both sides containing polymer layers with metallic or dielectric layers a higher refractive index is necessary. In addition to the radiation intensity this also significantly increases security, because of the geometry and optical properties of the resonator, the number of peaks and their Set position in the wavelength range of fluorescence. In addition, also set the peak width using the geometry used.

In a first embodiment it is provided that the dyes directly into a To bring in the layer and / or print position of the value and security document, wherein the reflective and / or dielectric layers are parts of the value and Represent security document. This creates a laser-active element i.e. a resonator that is characteristic of excitation with laser light or another high-energy light.

In a further embodiment it is provided that the laser-active element is not formed as part of the layer structure of the value and security document, but that the laser-active elements are produced separately from the value and security document in the form of independent resonators and only then in the form of pigment Platelets, chopsticks or spheres, the size of which is, for example, a few μm, are introduced into or placed on the document.
The production of such resonators for applications in security printing products is feasible, for example, using thin-film technology. After the individual, μm-thick layers, ie at least one reflective layer, one layer with dyes and a further, reflective layer, have been deposited on a film substrate, the layer composite is comminuted, for example by breaking. The sheet-like fragments obtained in this way, which are also referred to below as flakes or pigment platelets, with a thickness of 1 - 10 µm and an area <20 x 20 µm ^2, can then, depending on their size ^, be printed in appropriate inks (e.g. steel engraving , Screen printing, offset, letterpress) or be integrated into the paper and foil material of the security document.

The use of geometrically different resonators leads to a characteristic, extremely difficult to adjust peak pattern (fingerprint) of the "mixture" used. In addition to the non-commercial excitation wavelength, the threshold energy (minimum energy for the excitation of a laser emission) would also be a further security parameter for verifying such security features. Laser dyes can be used as a hidden or two-stage security feature that can be controlled with UV light, because, as already mentioned, all laser dyes show broadband UV fluorescence.
The following sections describe ways of incorporating laser dyes into different components of security and value products.

Basic material (paper, plastic films)

The incorporation of polymer-bound laser dyes into the paper can either by directly adding the bound dyes to the raw material mixture or by screen printing after drying respectively. The direct addition has the economic disadvantage that large Amounts for sufficient luminance must be added. On subsequent application to the paper by screen printing requires much smaller amounts of laser dyes and enables additionally a structuring in the sense of a watermark. At transparent, colorless laser dyes could be "hidden" Watermark "can be introduced into the paper. When used different laser dyes made hidden, colored watermarks produce.

In comparison to the direct insertion into or onto the paper, the Card area a very thin plastic film "doped" with the laser dyes or printed. Due to the specific map structure, it can be used with Insert the foil provided with laser dyes in the middle of the laminate composite. This leads to chemical-physical protection of the dyes Environmental influences, e.g. UV light and for a higher security through the close material bond between laser dye and polymer layer.

Paper additives

Another possibility for integrating the laser dyes is the combination with so-called additives, such as plastic threads, fibers or planchettes. Plastic threads are partially metallized as window threads in security and security paper during manufacture. To increase security, these window threads are also provided with a micro script. The micro script can be produced chemically (etching) or physically (laser ablation). The exposed areas appear as windows. In this case, the connection to laser dyes could again be made via the plastic phase. As already mentioned, the laser dyes can be easily integrated into the plastic matrix. In the case of excitation from above, below or from the side by means of a suitable laser light, the micro-writing would then light up, for example blue, depending on the laser dye selected. Similar to the window threads, fibers or planchettes could also be provided with laser dyes. In the case of fibers, there are options for introducing the laser dyes into the fiber material, filling the fibers when using hollow fibers (d _i > 10 µm) or one doped with laser dyes. To use polymer matrix as a covering (d <2 µm) of the fibers. Planchettes can be coated or doped in a similar way to fibers.

When introducing such laser dyes into plastic threads, glass fibers and other transparent fibers, especially textile fibers, consists of The advantage that practically a kind of laser resonator is generated with it. If one imagines that a plastic thread of limited length to the is mirrored on both ends and this is excited with a laser. Then there is a resonance phenomenon, d. H. this plastic store itself works as a laser, because the irradiated radiation along to a stimulated emission the fiber leads. As with the tiles already described, the length determines the peak as well as the reflection at the fiber ends Half-width of the emission peaks. It is not even necessary that the end faces are mirrored; non-mirrored end faces are also sufficient out. The prerequisite for this is that the dye in the plastic store is embedded, is sufficiently efficient. This is a matter of course not limited to the use of plastic threads alone, so it can any fibers can be used. But this gives the general Operating principle of the invention, d. H. so on the general embedding of such laser-excitable dyes in the value and security document, with the aim generate an appropriate resonance to produce sharp-banded peaks enable.

The present invention is not based on the excitation by means of a Lasers limited; other high-energy optical systems can also be used Excitation media are used, such as. B. a flash lamp, sodium or High pressure lamps and the like. A suggestion is also possible Luminescent diodes not only in the visible, but also in the invisible Wavelength range possible.

Printing inks

The main use of laser dyes in valuable and security products is in direct insertion into a printing ink. These include steel engraving, screen printing and Offset inks (wet, dry offset and indirect letterpress printing) as well as inks for letterpress printing (numbering) and other for value and Security printing relevant printing process. There is one for each of these colors individual adjustment between printing ink and to be added Laser dyes, whether in molecular form or as a solid matrix, are necessary. If resonators are used, their shape (usually Platelets but also balls) and size for the transfer from the color to the Decisive material. While in steel engraving and screen printing in general Dye pigments up to a size of 20 µm printed without problems there is an upper limit of 2 to 4 µ in the offset. Form (Tiles or balls) has an impact on manufacturing costs, the Can be mixed into the printing ink (rubbing chair), the stability, the light output and the spectral distribution / line shape. Spherical structures are simpler manufacture and are mechanically more stable. This is at the expense of one poorer processing properties and lower resonator efficiency. The The production of platelets is technically complex and expensive, but usually leads to to a higher luminous efficacy as well as defined, adjustable peak patterns. Furthermore, the use of tiles allows the use of the Radiation geometry, you get anisotropic radiation. So you could theoretically a high one with a thin ink application, like with offset printing Achieve emission intensity. In general, the optical effects are reduced with a decrease in the active layer thickness (steel engraving up to 20 µm, offset 1 to 4 µm). Due to the color components of printing inks, it is also conceivable Integrate dye solutions directly into a component of the color. A Offer the opportunity to do this e.g. the resin components (rosin) of highly viscous steel engraving colors or a combination with existing ones Color or effect pigments through joint encapsulation. Inks are a stabilizer for unencapsulated laser dye solutions. In With regard to the color matching and the effect, the colors, which as Carrier media for the laser dyes do not have strong covering properties have and if possible be transparent. Introducing the solved or Bound laser dyes in the printing inks should be added directly to the Color mixture consisting of solvents, pigments and additives to be possible. Due to the strong effect, concentrations are in the sub% range sufficient and for reasons of economy as an upper limit to watch.

Combination with other security features

In addition to the incorporation of laser dyes into the starting products, there is also Combination with other security feature, be it as a hidden feature Increased protection, as a source of excitation for secondary effects e.g. UV fluorescence or phosphorescence, as backlighting from Holograms or other diffraction structures and as a supplement to Information where only part of the hidden ones without laser excitation Information with a tool (e.g. lenticular grid) is conceivable. The Combination of laser dyes with fluorescent fibers, planchettes and Window threads have already been described above. Another interesting variant would be the combination with electroluminescent (EL) pigments. The wrapping of inorganic. EL pigments doped with a laser dye Polymer phase with almost non-adjustable security feature different verification levels. UV excitation would be one Mixed fluorescence consisting of portions of EL pigments as well as portions of the laser dyes generate an excitation by means of a suitable one Laser beam would probably only excite the laser dyes, as for one Excitation of EL pigments using a pulsed laser beam Field portion of the laser light is unsuitable, and eventually one would electrical excitation to make the EL pigments glow. In addition to the there is certainly an interaction of individual effects, or mutual influence of the effects, since the simultaneous action different sources of excitation the band structure of the available materials and thus affect the impact.

The subject matter of the present invention results not only from the subject matter of the individual patent claims, but also from the combination of the individual patent claims with one another.
All of the information and features disclosed in the documents, including the summary, in particular the spatial design shown in the drawings are claimed to be essential to the invention, insofar as they are new to the prior art, individually or in combination.

In the following, the invention is explained in more detail with reference to drawings showing several possible embodiments. Further features and advantages of the invention which are essential to the invention emerge from the drawings and their description.
In principle, there are no restrictions on use for security and security printing. As examples, suggestions for the integration of laser dyes in plastic cards (ID card, EU driver's license, credit cards) ID cards and banknotes are listed.

Figur 1:

schematisiert ein grundsätzlicher Aufbau eines Pigment-Plättchens, welche in ein nicht näher dargestelltes Wert- und Sicherheitsdokument eingebettet ist, oder welches in eine entsprechende Farbe eingebettet ist, die auf dem Wert- oder Sicherheitsdokument aufgedruckt oder angebracht ist;

Figur 2:

zeigt die Einbringung derartiger Pigment-Plättchen nach Figur 1 in ein Papier;

Figur 3:

zeigt die Einbringung derartiger Pigment-Plättchen in eine Kunststoffolie;

Figur 4:

zeigt die Einbringung derartiger Pigment-Plättchen in eine Farbe zum Bedrucken von Papier- oder Kunststoffolien;

Figur 5:

zeigt einen laseranregbaren Fensterfaden in einem Wert- und Sicherheitsdokument;

Figur 6:

schematisiert einen Schnitt durch das Dokument nach Figur 5;

Figur 7:

Querschnitt durch eine Faser mit Einbringung der Pigment-Plättchen;

Figur 8:

der Querschnitt durch den oberen Teil eines Wert- oder Sicherheitsdokumentes mit in eine Druckfarbe eingebrachten Pigment-Plättchen;

Figur 9:

die Anwendung der erfindungsgemäßen Technik bei einer Kunststoffkarte mit Beleuchtung bei Tageslicht;

Figur 10:

die gleiche Darstellung wie Figur 9 bei Beleuchtung mit Laserlicht;

Figur 11:

Darstellung eines Personaldokumentes bei Beleuchtung mit Tageslicht;

Figur 12:

Die gleiche Darstellung des Dokumentes bei Beleuchtung mit Laserlicht;

Figur 13:

Eine Banknote bei Beleuchtung mit Tageslicht;

Figur 14:

Die Beleuchtung der gleichen Banknote mit Laserlicht;

Show it:

Figure 1:

schematized a basic structure of a pigment plate, which is embedded in a value and security document, not shown, or which is embedded in a corresponding color, which is printed or attached to the value or security document;

Figure 2:

shows the introduction of such pigment flakes according to Figure 1 in a paper;

Figure 3:

shows the introduction of such pigment platelets in a plastic film;

Figure 4:

shows the introduction of such pigment platelets in a color for printing on paper or plastic films;

Figure 5:

shows a laser-excitable window thread in a value and security document;

Figure 6:

schematized a section through the document of Figure 5;

Figure 7:

Cross section through a fiber with the introduction of the pigment platelets;

Figure 8:

the cross section through the upper part of a value or security document with pigment plates inserted into a printing ink;

Figure 9:

the application of the technology according to the invention in a plastic card with illumination in daylight;

Figure 10:

the same representation as Figure 9 when illuminated with laser light;

Figure 11:

Presentation of a personal document when illuminated with daylight;

Figure 12:

The same representation of the document when illuminated with laser light;

Figure 13:

A banknote when lit by daylight;

Figure 14:

Illuminating the same banknote with laser light;

FIG. 1 generally shows a pigment lamina 1 which consists of two reflective layers 2 which are essentially parallel to one another and have a mutual spacing and which are applied to a polymer layer 4. The reflective layers 2 consist of an oxide layer, for. As silicon dioxide, silicon liquid, tin oxide, titanium oxide and the like. But it can also be a metallic layer. It is only essential that two reflecting layers 2 lie opposite one another, which, as it were, receive the polymer layer as a mirror between them and the laser dyes 3 are embedded in the polymer layer 4.
In addition, it can be provided that, according to FIG. 1, the end faces of the pigment plate 1 are also provided with the reflective layers 2.

The polymer layer 4 consists of a plastic polymer. Instead of a polymer layer, however, a glass layer or another transparent support can be used, which must be both transparent to the exciting wavelength and transparent to the emitting wavelength. It is therefore not necessary to use a polymer layer 4, but any transparent carrier layers can be used. It is not necessary that they be transparent in visible light, but that they can also be transparent in invisible light.
In another embodiment, the electrical layers mentioned above can also be omitted and only reflecting layers can be present on the end faces.

A large number of substances can be used for the laser dyes 3 which are present in molecular grain size.
Such dye laser systems have already been verified on the basis of thin-layer systems (DCM-doped polymer waveguides) and ASPT-doped polymer rods [JD Bhawalkar, et al., Opitcs Communication 124, 1996, 33]. For example, Rhodamine 6G can also be used.

For economic reasons, a relatively low concentration of the Laser dye particles 3 aimed in the polymer layer 4. This is the However, the invention is not limited; it can also provide that such Particulate and molecular laser dyes 3 are clustered or are distributed very differently in the density in the polymer layer 4. A uniform density distribution is therefore not necessary for the solution.

The example according to FIG. 1, with one used as pigment plate 1 Dye 3 is not limitative of the present invention. Because it can instead of the pigment plate shown here with the two together opposite and reflecting layers 2 also Security document can be used, which this pigment plate 1 not includes. The two reflective layers would then be directly in the Security document integrated at a mutual distance parallel to each other and between the two reflective layers is the one with Carrier layer doped with laser dye molecules, e.g. a polymer layer, arranged. The result is a laser-active element or a laser-active element Area on the security document that comes from between the two reflective layers embedded and doped with laser dye Carrier layer exists. This means that the illustration according to FIG. 1 can also be used magnified ten thousand times directly as a layered document be considered.

It follows that the invention is not based on the introduction of pigment platelets 1 according to Figure 1 in different value and security documents is limited, but that value and security document itself can have such reflective layers, between which a transparent Polymer layer is arranged, which is present with said molecular Laser dyes is doped.

2 shows a paper 5 in which the pigment platelets according to FIG installed and distributed. For the distribution of the pigment platelets in paper 5 the same applies as above for the distribution of the laser dyes 3 in the Polymer layer 4 was said. It is not necessary for the pigment platelets to have a solution are arranged in a relatively thin distribution in the paper. You can also form clusters; they can also be distributed on the surface or they can also be close to each other. In areas where there are flakes overlay, the irradiated radiation can be impeded, because the pigment platelets partially cover each other and thus the excitation is weakened. There are then interference effects which the emitted Attenuate radiation. Such a distribution in the paper should be chosen be that the pigment platelets do not interfere and interfere with each other.

Figure 3 shows a similar representation where it can be seen that the pigment platelets 1 are embedded in a plastic film 6. The plastic film can have any thickness.

Figure 4 shows that a printing ink 7 is arranged on a carrier 8, wherein this carrier 8 can be a value and security document. In the printing ink 7, the pigment platelets 1 are embedded. The ink 7 itself should be on the emitted spectrum of the pigment platelets 1 can be adjusted to a to achieve sufficient emission radiation. The printing ink must also to be transparent to the stimulating as well as the emitted radiation to ensure any excitation of the pigment platelets 1 at all.

FIG. 5 shows the integration of a Window thread in a value and security document 9. This is around a window thread 10, which is known in view of the value and Security document 9 is integrated, wherein Figure 5a shows that the Window thread 10 is recessed in the area of the label 11, and / or Has cup-shaped depressions or has recesses which with the Laser dye are filled. So that means a color is used that is doped with the pigment plate 1. Will the window thread 10 now with the stimulated appropriate light, then this printing ink comes very strong Illuminate as shown in Figure 5a.

FIG. 6 shows a cross section through the representation according to FIG. 5, it being evident that a color 13 doped with pigment platelets 1 is applied to the paper or plastic substrate 5. The metallized thread (window thread 10), which has the microtext shown in FIG. 5a, is arranged above it. Instead of the specified text, a geometric pattern can also be applied. There is a partially covering paper layer 12 so that the surface of the window thread 10 is only partially visible.
After the window thread has been cut out in the area of the inscription 11, the dye layer 13 underneath comes to view through these cutouts. If the window thread 10 is now excited from above, then this laser dye layer 13 lights up and shines through the cutouts of the window thread 10.

FIG. 7 shows a cross section through a fiber 15, which fiber can be a plastic thread, a textile thread, a glass thread, or the like. Various possible ways of introducing the pigment platelets 1 according to the invention at different locations on this fiber 15 are shown here. Assigns e.g. B. the fiber 15 on a fiber jacket 14, then it can be provided that the pigment flakes 1 in the region of the fiber jacket (alone or in combination with other layers of the fiber) are arranged. You can therefore attach a corresponding fiber jacket 14 with the pigment flakes 1.
It is also possible to introduce the pigment platelets 1 directly into the fiber 15 or also into a fiber cavity 16. Here it can be provided that the fiber cladding 14 has a different optical refractive power than, for example, the fiber 15 itself. For example, if a fiber cladding 14 is used, which allows total reflection, it is ensured that the light incident on the outside of the fiber cladding 14 passes through the fiber cladding 14 practically without reflection and enters the fiber 15, where there is a particularly favorable excitation of the pigment platelets arranged there 1 is coming.

However, the invention is not based on the integration of such pigment platelets 1 in such a fiber 15 is limited. It is in a further development of the invention suggested that instead of the pigment platelets, the laser dyes in molecular Distribution can be introduced directly into the material of the fiber 15. Instead of Pigment platelets 1 which are shown in FIG. 7 then occur directly before mentioned laser dyes 3 in molecular distribution. To now one corresponding resonance excitation of these laser dyes 3 in the fiber 15 7a ensure that the end faces 17, 18th this fiber 15 are mirrored. Now such a fiber 15 from the outside excited with a suitable radiation, then there is a pumping process between the end faces 17, 18 through the fiber 15, where now through the Laser dyes 3 arranged in molecular distribution directly for lighting up to be brought. Corresponding emitted laser radiation then occurs on the End faces 17, 18, as is known in a fiber laser.

FIG. 8 shows the integration of a printing ink 7 on a paper 5, the aforementioned pigment platelets being arranged in so-called polymer sleeves 19. Pigment platelets are thus introduced into a matrix, a polymer shell 19, and this acts like a microencapsulation on the pigment platelets, which can thereby be integrated in the printing ink 7 at low cost. It is important that the polymer sleeve 19 can also serve as a carrier for an electroluminescent excitable pigment 20.
This has the advantage that when the printing ink 7 is excited by means of a suitable laser radiation, the pigment platelets 1 first light up. If a pigment 20 that can be excited via electroluminescence or another security pigment is additionally used, then additional radiation can be generated which is superimposed on the other radiation. Such pigments 20 can, for example, be illuminated by a corresponding electrostatic field, and their radiation can be superimposed on the radiation emitted by the pigment platelets 1. The wavelength of the light emitted by the pigments 20 can shift due to the laser emission of the pigment platelets 1. This leads to an improved safety effect of this arrangement, because this mutually superimposing radiation is very difficult to imitate.

In FIG. 9, a plastic card 21 is shown in the known manner when illuminated with daylight, which has a photo area 22 and a labeling field 23.
If this plastic card 21 is irradiated with laser light, the appearance according to FIG. 10 results. The laser light is used to excite hidden features. In this case, a first security element 24 is present, which is applied into the inscription space via the photo surface 22. In the exemplary embodiment, it consists of three different sector colors 25, which complement each other to form a circle, which consequently only light up when excited with the aforementioned laser light.
A window thread 10 is also shown, which extends through both the photo surface 22 and the labeling field 23 and other surfaces of the plastic card 21. This window thread can also have the aforementioned microtext; it can be designed to be illuminated.
The same applies to the printing thread 26, which can not only consist of a metallized thread, but which is printed in the form of a print and extends over the image and the labeling field in order to make forgeries visible in these areas.
Finally, for example, another security element 27 is shown in the form of a geometric element, which, for. B. is suitable for machine evaluation.

Another example of a personal document 28 is shown in FIGS. 11 and 12 differently concealed features. Again, it is one Photo area 22 and a labeling field 23 available. It can be seen in FIG. that two overlapping printing threads 26 are provided, both the Cover photo area 22 as well as labeling field 23. As another Example is the name of the holder of the personal document with a provided illuminating bar 29, which was overprinted with a printing ink, in which the pigment platelets 1 were distributed.

In the last exemplary embodiment according to FIGS. 13 and 14, a bank note 30 is shown which has a certain number of known features when illuminated with daylight.
When illuminated with a suitable laser to excite the laser dyes used, it can be seen that the security feature 31, which lights up in different colors in the form of a rosette, has now been excited accordingly with the laser light. The same applies z. B. also for the number field 32, which then lights up in a different color compared to the number field recognizable in daylight. It can also be seen that the value field 33 is overprinted with the same number but shifted to it, which lights up when excited with a laser of the appropriate color and energy. So this is also an additional security element.

A total of 3 different detection options are provided for the laser dyes shown here. First of all, the laser dyes shown here show fluorescence in the UV range.
If the pigment platelets 1 provided with the laser dyes are excited, then the previously described sharp emission lines in the emission spectrum occur due to the described resonance phenomena. Such an emission spectrum is now extremely suitable for machine evaluation of the authenticity features of such value and security documents. A number of security features can be queried and evaluated, such as B. Wavelength of the emitted radiation peaks, mutual position of the peaks, full width at half maximum, number of peaks and peak amplitude. These parameters depend on the laser color used, the excitation energy and the materials in which the laser color is embedded.

It is also pointed out that the sharp band produced here Emission radiation can be superimposed with other radiation emissions, as already illustrated using the exemplary embodiment according to FIG. 8 has been.

Drawing legend

1

Pigment platelets

2nd

reflective layer

3rd

Laser dye

4th

Polymer layer

5

paper

6

Plastic film

7

Printing ink

8th

carrier

9

Value and security document

10th

Window thread

11

Captions

12th

Paper layer

13

Dye layer

14

Fiber sheath

15

fiber

16

Fiber cavity

17th

Face

18th

Face

19th

Polymer shell

20th

pigment

21

Plastic card

22

Photo area

23

Labeling field

24th

Security element

25th

Sector color

26

Printing threads

27

Security element

28

Personal document

29

bar

30th

Banknote

31

Security feature

32

Numeric field

33

Word field

34

number

Claims (12)

Value and security document with optically stimulable dyes for authenticity testing, the dyes being applied to or incorporated into the value and security document, characterized in that
that the dyes (3) are embedded in a carrier material (4, 5, 6, 7) and together with this form a laser-active element. Value and security document according to claim 1, characterized in that the dyes (3) used in different value and security documents differ in their emission behavior, and thereby a reliable differentiation of the different value and security documents is possible. Value and security document according to claim 1 or 2, characterized in that the dyes (3) are embedded in a resonator which consists of a coating on both sides of the carrier material layer (4) containing the dye with reflective layers (2). Value and security document according to one of claims 1 to 3, characterized in that the resonators used in different value and security documents differ in their geometry and / or the materials used, and thereby a reliable differentiation of the different value and security documents is possible . Value and security document according to one of claims 1-4 , characterized in that the dyes (3) are introduced directly into a layer and / or print layer of the value and security document, the reflecting layers being parts of the value and security document (9) represent. Value and security document according to one of Claims 1 - 5, characterized in that the dyes (3) are embedded in pigment platelets (1) which consist of a carrier layer (4) doped with the laser dye and two essentially parallel carrier layers are built up between reflecting layers (2). Value and security document according to one of claims 1-5, characterized in that the dye (3) is embedded in pigment spheres which are constructed from a carrier material doped with the laser dye and a reflective layer surrounding the carrier material. Value and security document according to one of claims 1 to 7, characterized in that the carrier material (4-7) is a suitable material which is transparent both for the exciting wavelength and for the emitting wavelength. Value and security document according to one of claims 1-8, that the dyes (3), pigment platelets (1), sticks or balls with suitable materials (19) are microencapsulated. Value and security document according to one of claims 1 - 9, that the dyes (3), pigment platelets (1), rods or spheres directly are introduced into the color components of a printing ink (7). Value and security document according to one of claims 1 - 10, that the dyes (3), pigment platelets (1), rods or spheres directly in the paper (5) and / or plastic substrate (6) of the value and Security document are introduced. Value and security document according to one of claims 1 - 11, that the dyes (3), pigment platelets (1), sticks or balls in the paper additives used in the security and value document or -Additional elements (10, 11, 15, 24) are introduced.

Images