EP3470236B1 - Data carrier with luminescent motif areas - Google Patents

Description

The invention relates to a data carrier, in particular a document of value or security, with a substrate which is translucent in the visible spectral range with opposite first and second main surfaces and with luminescent motif regions arranged on both the first and the second main surfaces.

Data carriers, such as documents of value or identity documents, but also other valuable objects, such as branded articles, are often provided with security elements for security purposes, which allow the authenticity of the data carrier to be checked and which at the same time serve as protection against unauthorized reproduction. In this context, it has long been known to use luminescent substances to secure documents of value or identity documents. Various luminescent substances and luminescent colors are known for this purpose, the term luminescent substance including fluorescent substances, phosphorescent substances and anti-Stokes substances. Luminescent substances are also used for product protection and in the form of phosphorescent substances, for example for securing emergency exits.

Fluorescent security elements for documents of value are, for example, from the publications GB 2 300 596 A and EP 2 028 017 A2 known. The security features described there are limited in their design options. Among other things, motifs with text components or digits cannot be used meaningfully, since they are displayed reversed in at least one of the test situations and therefore easily confuse the user. EP 2 028 017 A2 discloses the preamble of claim 1. In EP 2 028 017 A2 a first fluorescent layer between two opaque layers with recesses and a second fluorescent layer are provided on one or on two transparent, ie non-translucent, substrates. In the register with the cutouts of the first opaque layer, a colored opaque layer can be present on the second opaque layer. The layers opaque in visible light can also be opaque for UV light.

Proceeding from this, the object of the invention is to specify a data carrier of the type mentioned at the outset with an attractive appearance and high security against forgery.

This object is solved by the features of the independent claims. Further developments of the invention are the subject of the dependent claims.

• auf der ersten Hauptfläche ein erster lumineszierender Motivbereich angeordnet ist, der bei UV-Anregung in einer ersten Lumineszenzfarbe luminesziert,
• auf der zweiten Hauptfläche ein zweiter lumineszierender Motivbereich angeordnet ist, der bei UV-Anregung in einer zweiten, unterschiedlichen Lumineszenzfarbe luminesziert,
• zwischen dem ersten und zweiten lumineszierender Motivbereich ein UV-Absorber angeordnet ist, und
• überlappend zum ersten lumineszierenden Motivbereich auf der zweiten Hauptfläche ein farbiger Motivbereich angeordnet ist, der die erste Lumineszenzfarbe absorbiert, wobei der farbige absorbierende Motivbereich die zweite Lumineszenzfarbe nicht absorbiert.

According to the invention it is provided in a generic data carrier that

• a first luminescent motif region is arranged on the first main surface, which luminesces in a first luminescent color when excited by UV,
• a second luminescent motif area is arranged on the second main surface, which luminesces in a second, different luminescent color when excited by UV,
• a UV absorber is arranged between the first and second luminescent motif area, and
• A colored motif area which absorbs the first luminescent color is arranged overlapping the first luminescent motif area on the second main surface, the colored absorbing motif area not absorbing the second luminescent color.

Since the first luminescent motif area and the colored absorbent motif area are arranged on opposite main surfaces of the data carrier, the term “overlapping” refers to the vertical projection of the area covered by the areas into a common one Level. In the same way, the term "congruent" refers to a projection of the areas involved into a common level.

In principle, the UV absorber at least in some areas prevents the luminescent motif area arranged on the opposite main area from being excited to luminescence when the data carrier is exposed to UV radiation. The UV absorber absorbs at least the excitation wavelengths of one of the luminescent motif areas, preferably even the excitation wavelengths of both luminescent motif areas. The excitation wavelength ranges of the two luminescent motif areas can be the same or different.

The UV absorber can be part of a fiber-based substrate, for example in the form of TiO ₂ , can be part of an ink acceptance layer of a film substrate which is transparent per se, for example based on TiO ₂ , or can be present as a printing layer on a translucent substrate.

Due to the additional colored absorbing motif area and its possible adjustment to the second luminescent motif area, diverse interactions between the motifs of the luminescent motif areas can be generated with UV excitation from opposite sides of the data carrier. When the first main surface of the data carrier is exposed to UV radiation, the first luminescent motif area is excited to emit the first luminescent color, which is not only visible when the first main surface is viewed, but also appears when the second main surface is viewed due to the translucency of the substrate. There, however, the first luminescent color is removed from the places where the colored absorbing motif area is present absorbed and replaced, for example, by the intrinsic color and / or a further luminescent color of the colored absorbing motif area, as explained in more detail below.

In an advantageous embodiment it is provided that the first and second luminescent motif areas overlap at least partially. With particular advantage, the first and second luminescent motif areas are even congruent.

In an advantageous embodiment, the colored absorbent motif area is non-luminescent. In an advantageous embodiment, the intrinsic color of the colored absorbing motif area essentially corresponds to the luminescent color of the second luminescent motif area. When the second main surface of the data carrier is exposed to UV radiation and simultaneous presence of ambient light, the second luminescent motif area and the colored absorbent motif area then produce essentially the same color impression, so that the presence of the colored absorbent motif area is hardly noticeable in this lighting situation.

Alternatively, the colored absorbent motif area can also be luminescent. After UV excitation, he can emit the same luminescent color as the second luminescent motif area and thereby camouflage his presence again when the second main surface is exposed to UV. Alternatively, the colored absorbing motif area can also emit a different luminescent color than the second luminescent motif area. The first and / or second luminescent motif area is advantageously not visually recognizable, and is in particular transparent or has a white body color.

The colored absorbent motif area can be arranged from the substrate above the second luminescent motif area, but it can also be in a recess in the second luminescent motif area, or can be arranged below the second luminescent motif area and even below the UV absorber. In the latter case, the UV absorber can camouflage the presence of the colored absorbent motif area when viewed from the second main area.

The colored absorbent motif area advantageously contains, as an absorber, a dye or an organic or inorganic colored pigment, the intrinsic color of which is complementary to the first luminescent color. The colored absorbing motif area advantageously does not absorb broadband, but in particular selectively essentially only the first luminescent color.

In a further development of the invention, it can be provided that the colored absorbent motif region contains a thermochromic or photochromic substance as an absorber. The thermochromic or photochromic material only shows its effect when it is visually visible. For this purpose, a photochromic substance must be activated by UV excitation, and depending on the type, a thermochromic substance must be converted into the visually visible state by applying heat or cooling.

In an advantageous embodiment, in addition to the colored absorbent motif area already described, a further colored motif area is provided, which overlaps the second luminescent motif area is arranged on the first main surface and which absorbs the second luminescent color.

In currently preferred designs, the luminescent motif areas each show a monochrome motif when viewed with UV excitation and viewed from the same side. However, it is also possible for at least one luminescent motif area to display multicolored luminescent motifs. For example, at least one luminescent motif area can contain fluorescent white, which is formed from three basic fluorescent colors red, green and blue. The colored absorbing motif area can then filter out a part of the luminescent color spectrum on the opposite side and thus change the color impression there in a targeted manner.

The UV absorber advantageously contains titanium dioxide in the anatase or rutile modification, Tinuvin 400 or Tinuvin 460. The UV absorber can be arranged on each of the main surfaces of the substrate or can also be provided in the substrate itself.

In a development of the invention, the luminescent motif areas are screened and consist of a large number of similar screen elements. The colored absorbing motif areas (identical) are only rasterized in configurations. For example, tiles made of squares, triangles or circles can be considered as raster elements. The edge length of the grid elements or the grid spacing is advantageously in the range from 100 μm to 5000 μm, preferably in the range from 200 μm to 3000 μm.

The substrate is translucent, but preferably not transparent. In the context of the present description, translucency means light permeability, while transparency means image or view permeability. A Translucent but not transparent substrate therefore lets light through, but scatters so strongly that objects behind or below it cannot be seen from the opposite side. The translucent but not transparent substrate can be, for example, a paper substrate or a hybrid substrate with a paper layer.

The data carrier advantageously also contains at least one reference motif that is visible without stimulation, the appearance of which corresponds to the appearance of one of the luminescent motif areas after UV stimulation, and which can therefore be used by the viewer as a reference for the appearance of the motif areas.

The data carrier is advantageously a banknote, a passport, an identification card, a tax stamp, a voucher, a certificate, a certificate, a certificate or product security.

In all designs, the luminescent colors mentioned can each be fluorescent colors, phosphorescent colors or anti-Stokes colors.

• ein transluzentes Substrat mit gegenüberliegenden ersten und zweiten Hauptflächen bereitgestellt wird,
• das transluzente Substrat auf der ersten Hauptfläche mit einem ersten lumineszierenden Motivbereich versehen wird, welcher bei UV-Anregung in einer ersten Lumineszenzfarbe luminesziert,
• das transluzente Substrat auf der zweiten Hauptfläche mit einem zweiten lumineszierenden Motivbereich versehen wird, welcher bei UV-Anregung in einer zweiten, unterschiedlichen Lumineszenzfarbe luminesziert,
• zwischen dem ersten und zweiten lumineszierender Motivbereich ein UV-Absorber angeordnet wird, und
• überlappend zum ersten lumineszierenden Motivbereich auf der zweiten Hauptfläche ein farbiger Motivbereich angeordnet wird, der die erste Lumineszenzfarbe absorbiert, wobei der farbige absorbierende Motivbereich die zweite Lumineszenzfarbe nicht absorbiert.

The invention also includes a method for producing a data carrier of the type described, in which

• a translucent substrate with opposite first and second main surfaces is provided,
• the translucent substrate is provided on the first main surface with a first luminescent motif area which luminesces in a first luminescent color when excited by UV,
• the translucent substrate is provided on the second main surface with a second luminescent motif area which luminesces in a second, different luminescent color when excited by UV,
• a UV absorber is arranged between the first and second luminescent motif areas, and
• A colored motif area which absorbs the first luminescent color is arranged overlapping the first luminescent motif area on the second main surface, the colored absorbing motif area not absorbing the second luminescent color.

A UV hand lamp can be used to check the authenticity of the data carrier, or else a sensor system in which at least one image recording with UV excitation on a first side and one image recording with UV excitation on a second side are evaluated by means of an image sensor.

Further exemplary embodiments and advantages of the invention are explained below with reference to the figures, in the illustration of which a true-to-scale and proportioned reproduction has been dispensed with in order to increase clarity.

Fig. 1

schematisch das Erscheinungsbild einer erfindungsgemäß ausgestatteten Banknote nach Anregung mit UV-Strahlung, in (a) bei Betrachtung der Vorderseite der Banknote bei UV-Anregung von der Vorderseite, in (b) bei Betrachtung der Rückseite der Banknote bei UV-Anregung von der Rückseite, und in (c) bei Betrachtung der Rückseite der Banknote bei UV-Anregung von der Vorderseite,

Fig. 2

schematisch einen Querschnitt der Banknote der Fig. 1 im Merkmalsbereich zur Erläuterung des Aufbau der Banknote und des Zustandekommens des geschilderten Effekts bei UV-Bestrahlung der Banknotenrückseite, und

Fig. 3

eine Darstellung wie Fig. 2 bei UV-Bestrahlung der Banknotenvorderseite.

Show it:

Fig. 1

schematically the appearance of a bank note equipped according to the invention after excitation with UV radiation, in (a) when viewing the front of the bank note with UV excitation from the front, in (b) when looking at the back of the banknote with UV excitation from the back, and in (c) when looking at the back of the banknote with UV excitation from the front,

Fig. 2

schematically shows a cross section of the banknote of Fig. 1 in the features area to explain the structure of the banknote and the occurrence of the described effect with UV irradiation of the back of the banknote, and

Fig. 3

a representation like Fig. 2 with UV radiation on the front of the banknotes.

The invention will now be explained using the example of securing banknotes. Figure 1 shows schematically the appearance of a bank note 10 equipped according to the invention after excitation with UV radiation.

First shows Fig. 1 (a) the appearance of the banknote 10 when viewing the front 10V of the banknote with UV excitation from the same side, that is to say the front 10V. In this case, a fluorescent motif 14, here in the form of a segmented sphere, is visible in a feature area 12, the individual segments 16 all shining with red fluorescent color in the exemplary embodiment. Without excitation, the fluorescent motif 14 is not visible on the front 10V, since the segments 16 each have a white body color and are therefore not visible against the background of the white banknote paper.

Figure 1 (b) shows the appearance of the banknote 10 when looking at the back 10R of the banknote with UV excitation from the same side, that is Back 10R. In this case, the spherical motif of the front is also visible in the feature area 12 as the fluorescent motif 18, but is now continuously in blue color. Despite the continuous blue color impression, there is a difference in appearance: while segments 20A glow with blue fluorescent color, segments 20B appear with blue (or cyan) intrinsic color. Without UV excitation, only the segments 20B with their own blue color are visible, while the segments 20A have a white body color and are not recognizable against the background of the white banknote paper. The motif 18 is therefore partially visible on the back 10R without suggestion.

A surprising appearance now arises when the bank note 10 is viewed from the rear 10R, but the UV excitation occurs from the opposite side, that is to say the front 10V, as in FIG Fig. 1 (c) shown. In this case, the spherical motif is again visible in the feature area 12 as a fluorescent motif 22, but now with a two-tone color impression. While the segments 20A glow with red fluorescent color, the segments 20B appear with blue color. This two-tone effect is surprising for the user, since with one-sided UV excitation only one color is visible on each side. The security feature therefore has a high level of attention and recognition.

The structure of the banknote 10 in the feature area 12 and the occurrence of the described effect are now described with reference to Figures 2 and 3 explained in more detail.

First shows Fig. 2 schematically shows a cross section of the bank note 10 in the feature area 12, the back 10 R of the bank note pointing upward in the orientation shown. The banknote paper 30 of the banknote 10 is translucent but not transparent for UV radiation and for visible light. At least the banknote paper is translucent for the selected wavelength or the selected wavelength range. In the feature area, a first luminescent motif area 32 is arranged on the front 10V of the banknote 10 on the banknote substrate 30, which luminesces in a first luminescent color, in the exemplary embodiment in red luminescent color, when excited by UV. On the opposite rear side 10R, a second luminescent motif area 34 is arranged congruently with the first motif area 32, which luminesces in a second, different luminescent color when UV-excited, namely in the exemplary embodiment in blue luminescent color. The shape of the motif areas 32, 34 corresponds to the segments 16 and 20A, 20B of the spherical motif Fig. 1 .

Between the two luminescent motif areas 32, 34, a UV absorber layer 36 is provided on the back 10R, which prevents UV excitation radiation incident from the front 10V or back 10R from reaching the motif area arranged on the opposite side. This ensures that UV excitation radiation incident from the front 10V only excites the first motif area 32 and UV excitation radiation incident from the rear 10R only the second motif area 34 for luminescence.

Finally, a colored motif area 38 in the form of the segments 20B is arranged on the second luminescent motif area 34 in a partial area, which is the first (ie present red) luminescent color of the first luminescent motif area 32 is absorbed. The colored motif area 38 has an intrinsic color visible without excitation, in the exemplary embodiment a blue intrinsic color which essentially corresponds to the blue luminescent color of the second luminescent motif region 34.

Still referring to Fig. 2 the second luminescent motif region 34 is excited to luminescence 42 with blue luminescent color when UV radiation 40 is applied to the back of the banknote 10R. The UV absorber 36 prevents the UV radiation 40 from reaching the feature area 32 arranged on the front 10V and stimulating luminescence. Since the motif area 38 also has a blue inherent color 44, the spherical motif 18 appears only with a blue color when excited and viewed from the back of the banknote 10R, as in FIG Fig. 1 (b) shown. It is assumed that in addition to UV radiation 40, as usual, there is also ambient light in the visible spectral range (daylight or artificial light), which is reflected by the motif area 38 and makes its own color 44 visible.

On the other hand, when UV radiation is observed and the front of the banknote 10V is viewed, the first luminescent motif area 32 is excited to luminescence with red luminescent color. The UV absorber 36 prevents the UV radiation from reaching the feature region 34 arranged on the rear 10R and stimulating luminescence. The ball motif 14 thus appears only with a red color when excited and viewed from the front of the banknote 10V. The UV absorber 36 can be present in variants (not shown) on the front 10V, below the motif area 32, on both sides 10R and 10V of the substrate 30, in the substrate 30 or in combinations of the aforementioned variants.

Figure 3 illustrated according to the situation of the Fig. 1 (c) the conditions with UV irradiation of the front side of the banknote 10V and viewing from the opposite side of the banknote back 10R. The first luminescent motif area 32 is excited to luminescence 52 with red luminescence color by the UV radiation 50 of the front of the banknote 10V. Due to the translucency of the banknote paper 30, the red luminescent radiation 52 is also visible on the back of the banknote 10R.

Although the UV absorber 36 prevents the UV radiation 50 from reaching the feature region 34 arranged on the rear 10R, it does not block the red luminescent radiation 52 in the visible spectral range. However, the red luminescent radiation 52 is absorbed by the motif region 38, so that in the areas in which the motif area 38 overlaps the first luminescent motif area 32, it is not the red luminescent radiation 52 but the blue inherent color 44 of the motif area 38 that is visible instead. Here, too, it is naturally assumed that, as usual, in addition to UV radiation 50, daylight is also present, which is reflected by motif area 38 and makes its own color 44 visible.

As a result, in the case of front-side excitation and rear-side observation, the in Fig. 1 (c) illustrated, surprisingly two-tone appearance of the spherical motif 18th

In the exemplary embodiment, the colored motif area 38 is non-luminescent, but in other configurations it can itself contain a luminescent substance. This can be a blue luminous luminescent substance, for example, so that the in Fig. 1 (b) shown situation a homogeneous blue luminescent appearance of the spherical motif 18 results. Alternatively, the luminescent substance of the motif area 38 can also shine in a different luminescent color.

In another embodiment, the colored motif area 38 is not on the second motif area 34 but in a recess in the second motif area 34-in Fig. 2 also arranged on the UV absorber 36. With UV excitation 50 from the rear 10R, the red luminescence radiation 52 is also visible in this embodiment only in the areas outside the motif area 38, while the red luminescence radiation is absorbed in the motif area 38 and the inherent color of the motif area 38 is visible instead. The motif area 38 can be non-luminescent or also luminescent, wherein the luminescent color can be the same or different from the luminescent color of the second motif area 34.

In a further variant, the absorbent motif area 38 is arranged below the UV absorber 36, so that the latter can visually hide the second motif area 34 on the rear side 10R. The motif area 38 is then visible with UV excitation from the front 10V and viewed from the rear 10R. For example, the UV absorber 36 may consist of TiO ₂ with a layer thickness sufficient for visual coverage. In this case too, the motif area 38 can be non-luminescent or luminescent with any luminescent color. The UV absorber 36 can also cover only a partial area of the second motif area 34 and / or the UV absorber can be present on both sides of the banknote or in the banknote paper 30.

It goes without saying that a plurality of colored motif areas with an absorption effect are also provided for at least one of the luminescent radiations can. For example, in addition to the red-absorbing motif area 38 arranged on the rear 10R, a blue-absorbing motif area 38 can also be arranged on the front 10V, which, for example, has a red inherent color. The interaction of the luminescent motif areas and the absorbent motif areas enables complex designs with a high securing effect to be created.

Furthermore, the motif area 32 can also consist of more than one fluorescent dye or luminesce with more than one fluorescent color. The color-absorbing motif area 38 will preferably absorb only one of the plurality of fluorescent colors.

In an embodiment not according to the invention, the second region 34 can be omitted. A different impression also arises for the viewer (but only) with UV excitation from the front 10V when viewed from the front 10V or the rear 10R.

Reference symbol list

10th

Banknote

10V, 10R

Front, back

12

Feature range

14

fluorescent motif

16

Segments

18th

fluorescent motif

20A, 20B

Segments

22

fluorescent motif

30th

Banknote paper

32

first luminescent motif area

34

second luminescent motif area

36

UV absorber layer

38

colored absorbent motif area

40

UV radiation

42

Luminescence

44

Own color

50

UV radiation

52

Luminescence

Claims (16)

1. A data carrier, in particular a value document or security document, with a substrate that is translucent in the visible spectral range with opposite first and second principal faces and with luminescent motif regions arranged on both the first and the second principal faces,

   - a first luminescent motif region is arranged on the first principal face, which luminesces in a first luminescent color upon UV excitation,

   - a second luminescent motif region is arranged on the second principal face, which luminesces in a second, different luminescent color upon UV excitation,

   - a UV absorber is arranged between the first and the second luminescent motif region, and

   - overlapping the first luminescent motif region, a colored motif region is arranged on the second principal face, said colored motif region absorbing the first luminescent color,

   characterized in that the colored absorbent motif region does not absorb the second luminescent color.
2. The data carrier according to claim 1, characterized in that the first and second luminescent motif regions mutually overlap at least partially.
3. The data carrier according to claim 1 or 2, characterized in that the first and the second luminescent motif region are configured to be congruent to each other.
4. The data carrier according to at least one of claims 1 to 3, characterized in that the colored absorbent motif region is non-luminescent.
5. The data carrier according to at least one of claims 1 to 3, characterized in that the colored absorbent motif region is luminescent and emits the same luminescent color as the second luminescent motif region after UV excitation.
6. The data carrier according to at least one of claims 1 to 5, characterized in that the colored absorbent motif region as a narrow-band absorber only absorbs the first luminescent color.
7. The data carrier according to at least one of claims 1 to 6, characterized in that the first and/or second luminescent motif region is not visually recognizable, and in particular is transparent or configured with a white body color.
8. The data carrier according to at least one of claims 1 to 7, characterized in that the colored absorbent motif region is arranged in a recess of the second luminescent motif region.
9. The data carrier according to at least one of claims 1 to 8, characterized in that the colored absorbent motif region contains, as the absorber, a dye or an organic or inorganic colored pigment, whose inherent color is complementary to the first luminescent color.
10. The data carrier according to at least one of claims 1 to 9, characterized in that the colored absorbent motif region contains, as the absorber, a thermochromic or photochromic substance.
11. The data carrier according to at least one of claims 1 to 10, characterized in that a further colored motif region, which absorbs the second luminescent color, is arranged on the first principal face in a manner overlapping the second luminescent motif region; and/or
    the first luminescent motif region luminesces in at least two luminescent colors, wherein the colored absorbent motif region does not absorb one of the at least two luminescent colors.
12. The data carrier according to at least one of claims 1 to 11, characterized in that the UV absorber contains titanium dioxide in the anatase or rutile modification, Tinuvin 400 or Tinuvin 460.
13. The data carrier according to at least one of claims 1 to 12, characterized in that the luminescent motif regions and the colored absorbent motif regions are each gridded and are composed of a multiplicity of grid elements of the same type.
14. The data carrier according to at least one of claims 1 to 13, characterized in that the data carrier contains at least one reference motif visible without excitation, whose appearance corresponds to the appearance of one of the luminescent motif regions after UV excitation.
15. The data carrier according to at least one of claims 1 to 14, characterized in that the data carrier is a bank note, a passport, an identification card, a fiscal stamp, a voucher, a certificate, a letter of reference, a deed or a product securing means.
16. A method for manufacturing a data carrier according to any of claims 1 to 15, in which

    - a translucent substrate with opposing first and second principal faces is supplied,

    - the translucent substrate on the first principal face is equipped with a first luminescent motif region, which luminesces in a first luminescent color upon UV excitation,

    - the translucent substrate on the second principal face is equipped with a second luminescent motif region, which luminesces in a second, different luminescent color upon UV excitation,

    - a UV absorber is arranged between the first and the second luminescent motif region, and

    - overlapping the first luminescent motif region, a colored motif region is arranged on the second principal face, said colored motif region absorbing the first luminescent color and not absorbing the second luminescent color.

Images