EP2996881B1 - Security element, production method, data carrier equipped with the security element and method for checking the authenticity - Google Patents

Description

The invention relates to a security element for data carriers, in particular for value documents, identity documents and the like. The invention further relates to a data carrier equipped with the security element, to a method for checking the authenticity of the data carrier and to a method for producing the security element.

For protection against counterfeiting, especially with color copiers or other reproduction methods, data carriers such as banknotes, securities, credit cards, identity documents, passports, certificates and the like, labels, packaging or other elements for product protection are provided with luminescent security elements. These include fluorescent fibers or planchettes (small colored discs), which are mixed as a security feature in paper production under the paper pulp. In addition, fluorescent security threads made of plastic, metal or other material are used, which are completely or partially embedded in the paper during paper production. Also known is the use of fluorescent imprints that are invisible or colorless in normal light, but fluorescent under UV light. Fluorescence is generally understood to mean a transient emission of light that ends within 10 ^-8 seconds. Instead of fluorescent inks and phosphorescent or photochromic inks are used. The luminous effect lasts for phosphorescent materials after the end of the irradiation, depending on the material from 10 ^-8 seconds to several seconds or hours. Photochromic ink changes color upon excitation with UV light. If the UV light source is removed, the color change takes for some time before the color returns to its original state. A special case of a photochromic printing ink is the iridescent photochromic printing ink. Iridescent or pearlescent colors contain transparent pigments consisting of tiny foil-covered tiny mica flakes. They cause an interference of the incoming light. This results in shiny, pearl-like shimmering effects with a change in color at different viewing angles or lighting angles.

From the EP 1 567 358 B1 For example, there is known a banknote security luminescent security element having two or more areas, each area containing a material or combination of materials, the two or more areas having substantially the same visible color under first viewing conditions, the visible light and various visible colors under second viewing conditions, wherein the second viewing conditions include a combination of visible light and UV light (see claim 1 of U.S. Pat EP 1 567 358 B1 ). Furthermore, from the EP 1 567 358 B1 a luminescent security element for securing banknotes, comprising two or more areas, each area containing a material or combination of materials, the two or more areas showing different visible colors under first viewing conditions, including visible light; Substantially the same visible colors under second viewing conditions, the second viewing conditions comprising a combination of visible light and UV light (see claim 2 of the EP 1 567 358 B1 ).

In addition, the interim patent published pursuant to Article 54 (3) EPC WO2014 / 082754A1 a Sichherheitselement for a disk with a motif of individual elements known, the individual elements each contain only two adjacent areas produced by printing technology.

Based on the above prior art, the present invention has the object, a security element of the aforementioned To provide a type that offers an increased level of security against counterfeiting and at the same time can be easily checked for authenticity. In addition, a data carrier with such a security element and a method for producing such a security element should be provided.

This object is achieved by the security element defined in the main claim. A method for producing the same, a data carrier with such a security element and a method for checking the authenticity of the data carrier are defined in the independent claims. Further developments of the invention are the subject of the dependent claims.

Summary of the invention

1. 1. (first aspect) security element for a data carrier, in particular a value document, comprising a carrier substrate whose front side has a macroscopic motif composed of a plurality of microscopic individual elements, wherein:
   • the microscopic individual elements each contain at least three, in particular four, adjacent areas produced by printing technology, which are designed so that the observer perceives a so-called first light-middle-dark contrast within each individual element under first viewing conditions, under second viewing conditions within each individual element perceives substantially uniform brightness and perceives, under third viewing conditions, within each individual element a so-called second bright-mid-dark contrast which is inverted compared with the first bright-mid-dark contrast; and
   • the microscopic individual elements in the observer cause a dynamic impression of the macroscopic motif with an oscillating change between the first and the third viewing conditions, and the first, second and third viewing conditions are defined as follows:
     • first viewing conditions: viewing under illumination with visible light;
     • second viewing conditions: viewing under illumination with a combination of visible light and ultraviolet light at substantially equal parts;
     • Third viewing conditions: viewing under illumination with ultraviolet light.
2. 2. (preferred) security element according to paragraph 1, wherein the macroscopic motif composing microscopic individual elements are arranged in the form of a flat cascade and the term cascade is an arrangement of successively connected individual elements to understand.
3. 3. (preferred) security element according to paragraph 2, wherein the microscopic individual elements within the planar cascade linear, rectilinear, circular or wavy are arranged one behind the other.
4. 4. (preferred) security element according to one of paragraphs 2 or 3, wherein the planar cascade comprises a plurality of arrangements of microscopic individual elements in which the microscopic individual elements each linear, rectilinear, circular or wavy are arranged one behind the other and configured the arrangements of the microscopic individual elements are that the dimensions of the microscopic individual elements are uniform within an array, but of Arrangement vary to arrangement and in particular continuously increase in one direction and / or decrease.
5. 5. (preferred) security element according to one of paragraphs 1 to 4, wherein the microscopic individual elements have a size of at least 0.1 mm x 0.2 mm and at most 5 mm x 10 mm, preferably a size of at least 1 mm x 2 mm and not more than 3 mm x 5 mm
6. 6. (preferred) security element according to one of the paragraphs 1 to 5, wherein the individual elements in the form of planar figures, in particular polygons, circles, circle-like figures or circular parts, are formed.
7. 7. (preferred) security element according to any one of paragraphs 1 to 6, wherein the microscopic individual elements each contain three adjacent areas produced by printing technology, of which exactly one area has a luminescent material that is invisible when illuminated with visible light and when illuminated with ultraviolet Light shows a bright visible color. The luminescent material may e.g. be mixed in a daylight color. In one alternative, the luminescent material and a daylight color may be screen printed next to each other so that the luminescent material is not mixed in the daylight color. According to a further alternative, the daylight color is present in a printing layer, above which a further printing layer comprising the luminescent material is applied.
8. 8. (preferred) security element according to any one of paragraphs 1 to 6, wherein the microscopic individual elements each contain four adjacent areas produced by printing technology, of which exactly two areas have a luminescent material, which is invisible when illuminated with visible light is and shows a bright visible color when illuminated with ultraviolet light. The luminescent material may for example be mixed in a daylight color. In one alternative, the luminescent material and a daylight color may be screen printed next to each other so that the luminescent material is not mixed in the daylight color. According to a further alternative, the daylight color is present in a printing layer, above which a further printing layer comprising the luminescent material is applied.
9. 9. (preferred) security element according to one of the paragraphs 1 to 7, wherein the microscopic individual elements each contain three adjacent areas produced by printing technology, of which:
   • a first region having a first color layer in a dark visible color and a second color layer formed above the first color layer and the second color layer containing a luminescent material under UV irradiation which is invisible when illuminated with visible light and a bright one upon illumination with ultraviolet light shows visible color;
   • a second region has a color layer in a medium or medium dark visible color; and
   • a third region has a color layer in a bright visible color.
10. 10. (preferred) security element according to one of the paragraphs 1 to 7, wherein the microscopic individual elements each contain three adjacent areas produced by printing technology, of which:
    • a first region comprises a color layer, and the color layer comprises a material in one dark visible color and another, under UV irradiation luminescent material, which when illuminated with visible Light is invisible and shows a bright visible color when illuminated with ultraviolet light;
    • a second region has a color layer in a medium or medium dark visible color; and
    • a third region has a color layer in a bright visible color.
11. 11. (preferred) security element according to any one of paragraphs 1 to 6 or paragraph 8, wherein the microscopic individual elements each contain four adjacent areas produced by printing technology, of which:
    • a first region having a first color layer in a very dark visible color and a second color layer formed above the first color layer and the second color layer containing a UV-luminescent material which is invisible when illuminated by visible light and when illuminated with ultraviolet light bright visible color shows;
    • a second region comprises a first color layer in a dark visible color and a second color layer formed above the first color layer and the second color layer contains a luminescent material under UV irradiation that is invisible when illuminated with visible light and a bright one upon illumination with ultraviolet light shows visible color;
    • a third region has a color layer in a medium or medium dark visible color; and
    • a fourth area has a color layer in a bright visible color.
12. 12. (preferred) security element according to any one of paragraphs 1 to 6 or paragraph 8, the microscopic individual elements each containing four adjacent areas produced by printing technology, of which:
    • a first region having a color layer and the color layer containing one material in a very dark visible color and another UV-luminescent material which is invisible when illuminated with visible light and exhibits a bright visible color when illuminated with ultraviolet light;
    • a second region having a color layer and the color layer containing one material in one dark visible color and another UV-luminescent material which is invisible when illuminated with visible light and exhibits a bright visible color when illuminated with ultraviolet light;
    • a third region has a color layer in a medium or medium dark visible color; and
    • a fourth area has a color layer in a bright visible color.
13. 13. (preferred) A security element according to any one of paragraphs 7 to 12, wherein the luminescent material is a fluorescent material, in particular a fluorescent ink or a fluorescent pigment.
14. 14. (Second aspect) data carrier, comprising a security element according to any one of paragraphs 1 to 13.
15. 15. (preferred) data carrier according to paragraph 14, wherein the data carrier is a value document, in particular a banknote, an identity document or a label.
16. 16. (Third aspect) A method of producing a security element according to any one of paragraphs 1 to 13, comprising the step of providing a carrier substrate and the step of producing microscopic individual elements on the front side of the carrier substrate, in particular by means of offset, flexo, sieve , Gravure, intaglio, or inkjet printing.
17. 17. (Fourth aspect) A method for verifying the authenticity of a data carrier, in particular a value document, according to paragraph 14 or 15, comprising the step of visually detecting the dynamic impression of the macroscopic motif defined in paragraph 1 by viewing the data carrier in daylight with the aid of a UV Light source, in particular a UV hand lamp, wherein the distance between the data carrier and UV light source is shortened in repetitive sequence and extended again.

Detailed description of the invention

The term "ultraviolet light" as used herein refers particularly to light having a wavelength in a range of 235 to 380 nm.

Instead of the term "visible light", the term "daylight" is used below.

The term "daylight color" is understood to mean a color based on light in a wavelength range from 380 nm to 750 nm. The synonyms body color and color are also used below.

The term "motif" is to be understood in particular as a pattern or a picture. The subject can also provide the viewer with information convey, for example, by having a character, a string or an image information.

The term "plane figure" is known in the art (see " Mathematical Formulary ", Konrad Wittwer KG, Stuttgart, 1984, pages 12-15 ). The planar figures include in particular the following elements: triangle, in particular right-angled triangle, isosceles triangle and equilateral triangle; Quadrangle, in particular square, rectangle, rhombus, parallelogram, kite quadrangle, trapezium, tendon quadrangle and tangent quadrangle; Circle; Circle-like figures, such as an ellipse; Circular parts, in particular circular section or circle sector (a circular section can be defined by the parameters r = radius, b = arc and α = center angle), circular ring (a circular ring can be defined by the parameters r = radius of the inner circle and R = radius of the outer circle can be defined) and annulus cut-out (an annulus can be defined by the parameters r = radius of the inner circle, R = radius of the outer circle, B = outer arc, b = inner arc and α = center angle).

The term "polygon" as used herein refers in particular to an n-corner with n≥3.

As used herein, the term "microscopic" is not to be understood as meaning "micrometer-sized" or the like, but is merely to be understood as relative. The microscopic individual elements (which are also referred to below simply as "microelements") are in each case perceptible to the viewer with the naked eye, ie without the use of optical aids, and are composed in an overall image, ie a macroscopic motif.

The invention is based on the idea of achieving a dynamic effect in a micro / macro image by the interaction of luminous colors or luminescent inks, in particular fluorescent inks, and body colors or colored inks by means of a suitable design. The dynamic effect is based on a light-dark interaction of a repeating microelement structure contained in the macroscopic motif and can, in particular, during oscillating (ie by a periodic "back and forth") of the transition of (1) the illumination of the security element with (2) a UV light / daylight lighting situation in approximately the 1: 1 ratio to (3) a substantially pure UV lighting situation can be observed. The thus created play of light of the microscopic individual elements causes a dynamic in the macroscopic motif. Decisive for the dynamic effect is the periodic change of the distance between the UV light source and the security element. The percentage ratio of daylight / UV light changes in particular in a range of 70/30 to 30/70. Since the human eye regards the brighter image components of a motif as superficial or dominant, the dynamic motion effect when changing the brightness of motif elements located close to one another, eg lines, points or circles, is particularly impressive. The change in brightness is produced by the change in the distance between the UV light source and the security element, whereby the illuminance of, for example, a fluorescent color increases quadratically in the course of the shortening of the distance. In this way, at a greater distance the brighter daylight color becomes dominant, at a smaller distance the fluorescent color, which otherwise appears darker in daylight.

The dynamic motion effect unfolds depending on the choice and arrangement of the microelements e.g. in the form of an optical illusion-induced rotational effect (i.e., the motion of a rotating wheel) or in the form of a "pumping action" otherwise known in holograms (i.e., the periodically changing three-dimensional appearance of a subject) or the like. A rotational effect can be e.g. by bringing together the microelements so that together they form a pattern with rotational symmetry, in particular a pattern with rotational symmetry and mirror symmetry. The joining of the microelements can take place without gaps or with spacing. For example, white areas or unprinted areas may be present between the individual microelements.

Particularly suitable for carrying out the invention are fluorescent pigments and fluorescent dyes (in particular organic colorants), the optical effect of which is based on their ability to absorb UV radiation and in the form of visible light without delay, ie with volatility, within 10 ^-8 Seconds ending light emission, to send out. Phosphorescent materials are less preferred, but can be used provided that the duration of the afterglow does not affect the detectability of the dynamic motion effect.

The security element according to the invention can be excitable in particular at two or more wavelengths and then show different fluorescent shades as a function of the wavelength.

The invention will be explained in more detail with reference to the following embodiment variants or examples in conjunction with the additional figures. The Examples are preferred embodiments, to which, however, the invention should in no way be limited. Furthermore, the representations in the figures of better understanding are highly schematized and do not reflect the realities. In particular, the proportions shown in the figures do not correspond to the conditions present in reality and serve exclusively to improve the clarity.

Figuren 1 bis 15:

die Ausführungsvariante eines Sicherheitselements, das nicht unter den Umfang der vorliegenden Ansprüche fällt; diese Ausführungsvariante wird lediglich des besseren Verständnisses der vorliegenden Erfindung erwähnt;

Figur 16:

eine Ausführungsvariante eines Sicherheitselements gemäß der vorliegenden Erfindung;

Figuren 17 bis 20:

vier Beispiele zur Erzeugung von mikroskopischen Einzelelementen, aus denen das makroskopische Motiv gemäß Fig. 16 zusammengesetzt sein kann.

In detail, the figures show:

FIGS. 1 to 15:

the embodiment of a security element that does not fall under the scope of the present claims; this embodiment is only mentioned for a better understanding of the present invention;

FIG. 16:

an embodiment of a security element according to the present invention;

FIGS. 17 to 20:

four examples for the production of microscopic single elements, from which the macroscopic motif according to Fig. 16 can be composed.

Fig. 10 illustrates the construction of a security element in a cross-sectional view. The illustrated security element does not fall within the scope of the present claims, but the embodiment shown is mentioned for a better understanding of the present invention.

The present invention is based on the principle of a dynamic color change game, which is obtained by combining a daylight color with a luminescent color. These basics are based on the FIGS. 1 to 15 described.

• Farbschicht 1: dunkelblaue Tageslichtfarbe
• Farbschicht 2: hellgrüne Tageslichtfarbe
• Farbschicht 3: gelbe Fluoreszenzfarbe

FIG. 10 Fig. 11 illustrates a carrier substrate, for example the paper substrate of a banknote, which has on its front side first motif elements (regions with the reference numbers 1 and 3) and second motif elements (regions with the reference number 2). The first and the second motif elements are each formed by color layers produced by printing technology, wherein the first motif elements each contain a lower color layer 1 and an upper color layer 3 and the second motif elements each comprise only one color layer 2. The color layers have the following properties:

• Color coat 1: dark blue daylight color
• Color layer 2: light green daylight color
• Color layer 3: yellow fluorescent color

The yellow fluorescent color of the color layer 3 is invisible when viewed in daylight alone and appears yellow when viewed in UV light.

FIGS. 1 to 3 show the structure of the printing plates for the production of in Fig. 10 shown security elements in plan view. In the Fig. 1 shown printing form is provided for the production of the color layer 1 in dark blue daylight color. Fig. 2 shows the printing plate for the production of the color layer 2 in light green daylight color. Fig. 3 shows the printing plate for the production of the color layer 3 in yellow fluorescent color.

Fig. 4 illustrates the construction of the compression, by the in the FIGS. 1 to 3 shown printing forms is available. The compression has an outer, rectangular border 4 and an inner region 5. The ink of the rectangular border 4 is exclusively on the in Fig. 1 shown printing form back. The inner region 5 contains one through the pressure forms of Fig. 1 and the Fig. 2 generated background pressure and several, by means of the printing plate of the Fig. 3 overprinted areas.

Fig. 5 shows the security element of Fig. 10 in top view when viewed in pure sunlight. The viewer perceives a first information formed by vertical, light green stripes 7 and a dark blue background 6.

Fig. 6 shows the security element of Fig. 10 in plan view when viewed substantially in pure UV light. The viewer perceives a second information formed by vertical, yellow stripes 10 and a very dark background 9.

Fig. 7 shows the security element of Fig. 10 in plan view when viewed under daylight and UV light in a ratio of about 1: 1. In the regions 11, the yellow fluorescent color with the underlying dark blue daylight color mixes by additive color mixing to a green which corresponds to the daylight green of the regions 12. Thus, as third information, a monochrome surface is created for the eye.

The conclusion of the in the FIGS. 5, 6 and 7 shown motifs is based on the in FIGS. 11, 12 and 13 illustrated cross-sectional views illustrated.

Fig. 11 shows the security element of Fig. 5 in the pure sunlight. Reference numeral 8 designates the color layers formed with fluorescent dye which are invisible under the present viewing conditions. The reference numerals 6 and 7 indicate the visible, formed with dark blue or light green daylight color layers.

Fig. 12 shows the security element of Fig. 6 in pure UV light. Reference numeral 10 denotes the color layers formed under the present viewing conditions and formed with yellow fluorescent color. Reference number 9 indicates the color layers formed with daylight color, which are invisible under the present viewing conditions.

Fig. 13 shows the security element of Fig. 7 when viewed under daylight / UV light in the ratio of about 1: 1. Reference numeral 11 denotes the green to be recognized by the additive color mixing of the yellow fluorescent color and the dark blue daylight color. The reference numeral 12 indicates the visible to the viewer, formed by daylight color green.

The dynamic light interplay in the course of the periodic movement of the UV light source is based on the FIGS. 8, 9 . 14 and 15 illustrated. In the course of reducing the distance between the UV light source and the object, the brightness of the fluorescent dye increases, conversely, this decreases as the distance increases. Compared to the fluorescent color, the brightness of the daylight colors changes inversely by reducing the amount of daylight when the object is immersed in a UV chamber or by shading by means of a UV flashlight moving above the object. In other words: reducing the distance to the UV lamp, the fluorescent color becomes lighter than the daylight color, as the distance increases, the daylight color becomes brighter than the fluorescent color.

FIGS. 8 (Plan view) and 14 (cross-sectional view) show the security element of Fig. 10 when viewed under daylight / UV light in the ratio of about 1: 2. The areas with the reference number 13 are perceived by the viewer with light green color, while the areas with the reference number 14 with dark green color.

Figures 9 (Plan view) and 15 (cross-sectional view) show the security element of Fig. 10 when viewed under daylight / UV light in the ratio of about 2: 1. The areas numbered 13 are perceived by the viewer with a dark green color, while the areas numbered 14 are perceived with a light green color.

<Embodiment 1>

Fig. 16 shows a macroscopic motif 15, in which many individual elements 16 are arranged in the form of a planar cascade. A cascade is an arrangement of cascaded, similar graphical elements to understand.

In planar, multiple arrangement of the individual elements is by a brightness shift (ie, an inversion or reversal of the contrast) creates the impression of a movement. Depending on the arrangement of the individual elements within the macroscopic motif and the nature of the individual elements, the direction of movement can be varied.

Due to the different brightness levels of the areas 17, 18 and 19 within a single element 16, a flowing movement effect in a specific direction is obtained in the macroscopic motif 15.

In the Fig. 16 the effect causes the overall picture 15 to be turned counterclockwise.

• der Größe eines Kaskaden-Elements 16,
• der Lichtstärke der UV-Lampe und der damit verbundenen Leuchtstärke der Fluoreszenz,
• dem Kontrast der Einzelelemente 16 verglichen mit dem gedruckten Umfeld,
• dem Helligkeitsunterschied von UV-Lampenlicht zu Tageslicht und
• von der Frequenz, mit der die UV-Lampe über dem gedruckten Element auf und ab, bzw. hin und her bewegt wird.

The quality of the movement effect depends, among other things, on

• the size of a cascade element 16,
• the intensity of the UV lamp and the associated luminous intensity of the fluorescence,
• the contrast of the individual elements 16 compared to the printed environment,
• the brightness difference from UV lamp light to daylight and
• the frequency at which the UV lamp moves up and down over the printed element.

Since, depending on the arrangement of the elements 16, the movement effect can take place in different directions, it is conceivable to generate motion effects in different directions within a macroscopic motif (for example, that in FIG Fig. 16 shown outer ring creates a counterclockwise motion effect, the next inner ring has a clockwise motion effect, etc.).

That in the Fig. 16 shown macroscopic motif 15 is composed of individual elements 16. The nature of a single element, more specifically the areas contained therein 17,18 and 19, is based on the FIGS. 17a to 17d explained in more detail.

That in the Fig. 17a shown single element has three areas A, B and C in three different brightness levels. The areas are generated in the present example by means of daylight color in the raster print, with each area a different area coverage is selected. That in the Fig. 17a The single element shown contains three areas with an area coverage of 10%, 50% and 100% respectively. The darkest area with a coverage of 100% is additionally equipped with a fluorescent paint 20 or is overprinted with fluorescent paint 20.

When changing from daylight to UV light, on the one hand there is a continuous brightening of the darker area A overprinted with fluorescent color 20, and on the other hand a darkening of the brighter areas B and C by shading by means of the UV lamp housing or the UV lamp (including the hand with UV -Handlampen) instead.

• d: dunkel;
  • d-m: dunkel bis mittel;
• m: mittel;
  • m-h: mittel bis hell;
• h: hell.

The in the FIGS. 17 to 19 existing abbreviations d (dark), m (medium or medium dark) and h (light) describe the brightness of the individual areas, where the abbreviations are structured with increasing brightness as follows:

• d: dark;
  • dm: dark to medium;
• m: medium;
  • mh: medium to light;
• h: bright.

Fig. 17b shows the brightness of the areas A, B and C of the single element when viewed in daylight.

Fig. 17c shows the brightnesses of the areas A, B and C of the single element when viewed in lighting with a combination of daylight and UV light to substantially equal parts.

Fig. 17d shows the brightness of the areas A, B and C of the single element when viewed in UV light.

In daylight the area C is the brightest, A the darkest. In the half / half situation, the darkest area becomes a little brighter, the brightest a little bit darker. The entire surface appears in a more or less uniform gray. Under UV light, the surface A is the brightest, the surface B the darkest. This shift in brightness from C to A gives the viewer the impression that the surface is moving from right to left.

<Embodiment 2>

In this example, this will be in the Fig. 16 shown macroscopic motif 15 composed of individual elements 16, wherein the nature of a single element, more specifically the areas contained therein 17,18 and 19, based on FIGS. 18a to 18d is explained in more detail.

That in the Fig. 18a shown single element has four areas A, B, C and D in four different levels of brightness. The areas are generated in the present example by means of daylight color in the raster print, with each area a different area coverage is selected. That in the Fig. 18a The individual element shown contains four areas with an area coverage of 10%, 40%, 70% and 100%, respectively. The darkest area with a coverage of 100% and the second darkest area with an area coverage of 70% is additionally equipped with a fluorescent color 21 or is overprinted with fluorescent ink 21.

When changing from daylight to UV light on the one hand finds a continuous brightening of the overprinted with fluorescent 21, darker areas A and B, on the other hand, a darkening of the brighter areas C and D by shading by means of the UV lamp housing or the UV lamp (including the hand in UV hand lamps) instead.

Fig. 18b shows the brightness of the areas A, B, C and D of the single element when viewed in daylight.

Fig. 18c shows the brightnesses of the areas A, B, C and D of the single element when viewed in lighting with a combination of daylight and UV light to substantially equal parts.

Fig. 18d shows the brightnesses of the areas A, B, C and D of the single element when viewed in UV light.

In daylight, surface D is the brightest, surface C the second brightest, surface B the darkest and surface A the second darkest. Due to the lightening of the two dark areas A and B under the UV lamp with simultaneous darkening of the light areas C and D, the entire area appears in a more or less uniform gray in the half / half situation.

Under UV light, this effect is further enhanced, so that position A appears as the brightest, position B as the second brightest surface. This shift in brightness from D to A gives the viewer the impression that the surface is moving from right to left.

<Embodiment 3>

According to a variant of the case described in the embodiment 2, further arrangements of the gray scale fields are within one in the Fig. 16 shown single element 16 conceivable.

Fig. 19a shows the brightness of the areas A, B, C and D of the single element when viewed in daylight.

Fig. 19b shows the brightnesses of the areas A, B, C and D of the single element when viewed in lighting with a combination of daylight and UV light to substantially equal parts.

Fig. 19c shows the brightnesses of the areas A, B, C and D of the single element when viewed in UV light.

In general, the realization of a single element can be carried out over any form of screening of a single color or as multicolor printing of different shades of gray or hues of different brightness or also by partial overprinting of two hues.

If the motif is printed rastered, the coverage ratio changes accordingly, since in this case there can be no 100% area coverage. In this case a maximum coverage of 70 to 80% is achieved.

The production is basically process-independent, ie it can be done for example by means of offset printing, intaglio printing, screen or flexographic printing. In the same way, the printing processes can be combined with one another, eg daylight color in offset, intaglio or screen printing and fluorescent ink in inkjet, screen or flexo printing.

<Embodiment 4>

In this example, this will be in the Fig. 16 shown macroscopic motif 15 composed of individual elements 16, wherein the nature of a single element, more specifically the areas contained therein 17,18 and 19, based on FIGS. 20a and 20b is explained in more detail.

Fig. 20a shows the partial overprint of different colored areas 22 and 23 of different brightness. Surface 22 is blue, surface 23 light green. The fluorescent color is printed in this example congruent over the blue surface 22 or can be mixed into this. The brightest surface (with an area coverage or gray scale of 10%) is paper white.

Fig. 20b FIG. 12 shows the superimposition pressure having the blue area 24, the dark blue area 25, the light green area 26, and the white area 27.

Claims (17)

1. A security element for a data carrier, in particular a value document, comprising a carrier substrate whose front side has a macroscopic motif composed of a multiplicity of microscopic single elements, wherein :

   the microscopic single elements respectively contain at least three, in particular four, neighboring regions produced by printing technology which are so constituted that the viewer perceives a so-called first light/medium/dark contrast within each single element under first viewing conditions, perceives a substantially uniform lightness within each single element under second viewing conditions, and perceives a so-called second light/medium/dark contrast which is inverted compared to the first light/medium/dark contrast within each single element under third viewing conditions; and

   the microscopic single elements arouse in the viewer a dynamic impression of the macroscopic motif upon an oscillating change between the first and the third viewing conditions, and the first, second and third viewing conditions are defined as follows:

   first viewing conditions: viewing upon illumination with visible light;

   second viewing conditions: viewing upon illumination with a combination of visible light and ultraviolet light in substantially equal parts;

   third viewing conditions: viewing upon illumination with ultraviolet light.
2. The security element according to claim 1, wherein the microscopic single elements composing the macroscopic motif are arranged in the form of a planar cascade, and the term cascade is understood to be an arrangement of successively placed single elements.
3. The security element according to claim 2, wherein the microscopic single elements are arranged so as to be successively placed in a linear, straight, circular or wavy form within the planar cascade.
4. The security element according to either of claims 2 to 3, wherein the planar cascade comprises a plurality of arrangements of microscopic single elements in which the microscopic single elements are respectively arranged so as to be successively placed in a linear, straight, circular or wavy form, and the arrangements of the microscopic single elements are so configured that the dimensions of the microscopic single elements are uniform within an arrangement but vary from arrangement to arrangement, in particular increasing and/or decreasing continuously in one direction.
5. The security element according to any of claims 1 to 4, wherein the microscopic single elements possess a size of at least 0.1 mm x 0.2 mm and at most 5 mm x 10 mm, preferably a size of at least 1 mm x 2 mm and at most 3 mm x 5 mm.
6. The security element according to any of claims 1 to 5, wherein the single elements are configured in the form of plane figures, in particular polygons, circles, cycloid figures or parts of a circle.
7. The security element according to any of claims 1 to 6, wherein the microscopic single elements respectively contain three neighboring regions produced by printing technology, of which exactly one region has a luminescent material which is invisible upon illumination with visible light and shows a light visible color upon illumination with ultraviolet light.
8. The security element according to any of claims 1 to 6, wherein the microscopic single elements respectively contain four neighboring regions produced by printing technology, of which exactly two regions have a luminescent material which is invisible upon illumination with visible light and shows a light visible color upon illumination with ultraviolet light.
9. The security element according to any of claims 1 to 7, wherein the microscopic single elements respectively contain three neighboring regions produced by printing technology, of which:

   a first region has a first color layer in a dark visible color and a second color layer formed above the first color layer, and the second color layer contains a material luminescing under UV irradiation which is invisible upon illumination with visible light and shows a light visible color upon illumination with ultraviolet light;

   a second region has a color layer in a medium or medium-dark visible color; and

   a third region has a color layer in a light visible color.
10. The security element according to any of claims 1 to 7, wherein the microscopic single elements respectively contain three neighboring regions produced by printing technology, of which:

    a first region has a color layer and the color layer contains a material in a dark visible color and a further material luminescing under UV irradiation which is invisible upon illumination with visible light and shows a light visible color upon illumination with ultraviolet light;

    a second region has a color layer in a medium or medium-dark visible color; and

    a third region has a color layer in a light visible color.
11. The security element according to any of claims 1 to 6 or claim 8, wherein the microscopic single elements respectively contain four neighboring regions produced by printing technology, of which:

    a first region has a first color layer in a very dark visible color and a second color layer formed above the first color layer, and the second color layer contains a material luminescing under UV irradiation which is invisible upon illumination with visible light and shows a light visible color upon illumination with ultraviolet light;

    a second region has a first color layer in a dark visible color and a second color layer formed above the first color layer, and the second color layer contains a material luminescing under UV irradiation which is invisible upon illumination with visible light and shows a light visible color upon illumination with ultraviolet light;

    a third region has a color layer in a medium or medium-dark visible color; and

    a fourth region has a color layer in a light visible color.
12. The security element according to any of claims 1 to 6 or claim 8, wherein the microscopic single elements respectively contain four neighboring regions produced by printing technology, of which:

    a first region has a color layer and the color layer contains a material in a very dark visible color and a further material luminescing under UV irradiation which is invisible upon illumination with visible light and shows a light visible color upon illumination with ultraviolet light;

    a second region has a color layer and the color layer contains a material in a dark visible color and a further material luminescing under UV irradiation which is invisible upon illumination with visible light and shows a light visible color upon illumination with ultraviolet light;

    a third region has a color layer in a medium or medium-dark visible color; and

    a fourth region has a color layer in a light visible color.
13. The security element according to any of claims 7 to 12, wherein the luminescent material is a fluorescent material, in particular a fluorescent ink or a fluorescent pigment.
14. A data carrier, comprising a security element according to any of claims 1 to 13.
15. The data carrier according to claim 14, wherein the data carrier is a value document, in particular a bank note, an identity document or a label.
16. A method for manufacturing a security element according to any of claims 1 to 13, comprising the step of supplying a carrier substrate and the step of producing microscopic single elements on the front side of the carrier substrate by printing technology, in particular by means of offset, flexographic, screen, gravure, intaglio or ink-jet printing.
17. A method for checking the authenticity of a data carrier, in particular a value document, according to claim 14 or 15, comprising the step of visually detecting the dynamic impression, defined in claim 1, of the macroscopic motif by viewing the data carrier in daylight with the aid of a UV light source, in particular a UV hand lamp, with the distance between data carrier and UV light source being shortened and lengthened again in recurrent succession.

Images