WO2013045056A1

WO2013045056A1 - Security element comprising a plurality of optically variable structures and a kinematic effect

Info

Publication number: WO2013045056A1
Application number: PCT/EP2012/003942
Authority: WO
Inventors: Karlheinz Mayer; Thanh-Hao Huynh; Peter Franz
Original assignee: Giesecke & Devrient Gmbh
Priority date: 2011-09-30
Filing date: 2012-09-20
Publication date: 2013-04-04
Also published as: DE102011114644A1; EP2760679B1; EP2760679A1

Abstract

The invention relates to a security element comprising an optically variable structure that has an embossed structure, said embossed structure comprising a plurality of non-linear, elevated embossed elements. Furthermore, the optically variable structure comprises in at least a first partial region at least one first additional information that is obtained by varying the geometric shape of the non-linear embossed elements using shadowing effects. According to the invention, the at least one first additional information is obtained by at least a partial section from the geometry of the respective non-linear embossed elements so that said at least one partial section is missing in the respective geometric shape of the non-linear embossed elements.

Description

Security element with several optically variable structures and a kinematic effect

The invention relates to a security element with an optically variable structure having an embossed structure of a plurality of non-linear, raised embossing elements. In addition, the optically variable structure has, at least in a first subarea, at least one first additional information which is produced by variation of the geometric shape of the nonlinear embossing elements by shading effects. The invention further relates to a tool for producing this security element.

In order to avert counterfeit attempts of value documents, such as banknotes, securities, identity cards, credit cards, debit cards or the like, new security elements are constantly being sought. It is advantageous elements that have a corresponding tilting effect, as they are difficult to copy, but are easy to check and without tools. For this purpose, structures such as dots or lines are preferably used, which have a tilting effect by a clever arrangement with a background pressure.

WO 2006/018232 A1 discloses a generic security element for value documents with an optically variable structure which has an embossed structure and a coating. The embossed structure and the coating are combined with one another in such a way that at least parts of the coating are completely visible when viewed perpendicularly, but are hidden when viewed obliquely. The embossed structure consists of nonlinear embossing elements that are combined with the coating in such a way that different when changing the viewing direction Information becomes visible. At least a part of the non-line-shaped embossing elements is arranged in grid form and consists for example of embossing elements in the form of a tetrahedron, cylinder section or a pyramid.

From WO 2009/013000 A2, a security element for value documents with an optically variable structure is known, which has a first embossing structure of first embossing elements. This embossed structure is also combined with a coating that contrasts with the surface of the security element in such a way that at least partial areas of the coating are visible when viewed from a first viewing angle range, but at least partially hidden when viewed under a second viewing angle range. When the security element is tilted about a first axis, a first tilting effect thus arises. The optically variable structure has a second embossing structure which is arranged within the first embossing structure and generates a second tilting effect in addition to the first tilting effect. Here, the second embossed structure is introduced either in the first embossing elements by a partial change in the geometry of the first embossing elements or consists of second embossing elements, which are attached at a certain angle respectively to a flank of the first embossing elements.

A disadvantage of the cited prior art documents is, in particular, that the embossed structures require a multicolor structured background printing which appropriately supports the feature and makes it susceptible to color shifts due to strong register variations. Furthermore, a maximum of two information contents in combination with corresponding color impressions are made possible. As strong as possible colors should be used, which in practice are often not real. len, since they do not fit into the overall design of a banknote as one of the background colors, especially in a very bright and colorful design.

The invention is therefore the object of developing a generic security element or a tool for producing a generic security element such that the disadvantages of the prior art is eliminated and the protection against counterfeiting is further increased. This object is solved by the features of the independent claims. Further developments of the invention are the subject of the dependent claims.

According to the invention, the at least one first additional information is formed by at least one partial section of the geometry of the respective non-linear embossing elements. This means that the respective geometric shape of the non-linear embossing elements this at least a partial cutout missing. If a viewer looks at the optically variable structure from a viewing angle range from which he does not see or recognize the at least one additional additional information, the observer thus sees or recognizes the "intact" side of the embossing elements Structure from a viewing angle range, from which he sees or recognizes the partial cutouts from the geometry of the embossing elements, the flanks of the partial cutouts create a shading of the respective embossing elements, so that the viewer sees or recognizes the embossing elements in a darker shade than the "Intact" embossing elements. A tool for producing such security elements or embossing elements is, for example, a printing plate, in particular a gravure printing plate, or an embossing plate, in particular a blind embossing intaglio printing plate. A blind embossing gravure printing plate in this case is a gravure printing plate whose recesses are not filled with color, so that the substrate is only embossed but not applied to its surface with a color.

According to a preferred embodiment, at least a part of the non-line-shaped embossing elements substantially in the form of a tetrahedron, spherical section, truncated pyramid, cone, truncated cone, cylinder section, torus, oval, drop or a pyramid.

According to a further preferred embodiment, the partial cutout has the shape of a triangle, a quadrangle, a polygon or an arcuate subsegment. Of course, any other shape is possible, such as an irregular shape or the shape of a graphic illustration. Thus, for example, the partial cutout has the shape of a triangular shaped piece of cake cut out or cut out from one side of a cone or a sphere portion. The remaining cone remainder or remainder of the spherical section, which now lacks the triangular pie slice, forms the nonlinear shaped, embossed embossing element according to the invention. In the production of the embossing element of course, the partial cutout is not cut out of the embossing element. Rather, the embossing plate, with which the embossing element is produced, recesses, which already have the shape of the embossing element with the corresponding cutout or, as the embossing plate is known, the negative of the have embossing element, with a correspondingly shaped notch or indentation into the recess inside.

Of course, instead of raised embossing elements, recessed embossing elements are also possible. In this case, the embossing elements do not protrude out of the plane of the substrate surface, but form recesses in the substrate surface, the embossing elements thus protrude into the substrate. However, in this case, a corresponding embossing plate can not have elevations relative to the embossing plate level, since these would impair the wiping process, for example by means of a doctor blade. Rather, in this case, the elevations must be introduced in a recessed or lowered area of the embossing plate, such that the elevations do not project beyond the embossing plate level. These structures thus correspond to structures, as are known, for example, from WO 2010/075979 AI. Thus, FIG. 2 of WO 2010/075979 A shows a correspondingly embossed substrate, and FIG. 3 shows an embossing plate for producing embossed structures of FIG. 2.

According to a further preferred embodiment, the at least one first subarea has an outline shape which contains the at least one first additional information, wherein the at least one first additional information is visually recognizable to a viewer only under a first viewing angle range. When viewing the security element from an angular range that is different from the first viewing angle range, the first additional information is not recognizable to a viewer.

For example, the outline shape forms a letter, a digit, or a graphic image that is optically discernable only under the first viewing angle range, whereas from all other viewing angle ranges, an "intact" and nearly uniform area is discernible. The embossed structure thus forms a tilting image that reveals different information from different viewing angles, namely once a nearly uniform surface and once the outline shape within this almost uniform surface.

According to a further preferred embodiment, in at least one second subregion of the optically variable structure, at least one second additional information is formed by at least one partial detail of the geometry of the respective nonlinear embossing elements so that the respective geometric shape of the nonlinear embossing elements is missing at least a partial detail. This at least one second subarea also preferably has an outline shape which contains a second information, wherein the second information is optically recognizable to a viewer only under a second viewing angle range. Together with the first additional information thus results in at least two information that can be seen from different viewing angle ranges.

According to a preferred embodiment, the surface of the optically variable structure of the security element has a uniform color at least in the region in which the embossing pattern is arranged. Preferably, this hue corresponds to the hue of the substrate of the security element, in which the embossed structure is embossed. If the optically variable structure is embossed directly into a substrate made of paper, for example a banknote, and if the substrate has no additional printing in this area, the color tone corresponds to the color tone of the paper. In the current series of euro banknotes of the first series, the paper of each denomination is colored differently, for example the purple € 50 banknote and the green € 100 green banknote. However, particularly preferably, an imprint or a coating having a uniform hue is applied to the substrate of the security element before or after the introduction of the embossing elements according to the invention, which has a particularly high contrast between direct illumination and indirect or shadowed illumination. It has been shown that a metallic or metal-like hue has a particularly high contrast and thus causes a particularly pronounced tilting effect, since in this case the incident light is primarily reflected and diffuse only to a small extent. The imprint or the coating is applied to the substrate, for example by screen printing, as a silver-colored patch or as a silver-colored foil.

Particularly preferably, the embossing and the printing of the substrate are carried out in one operation, for example by using an ink-bearing intaglio printing. Here, the wells of a gravure printing plate are at least partially filled with one or more different colors, so that not only deformed or embossed when printing the substrate of the printed material, but also applied with color.

The surface of the embossing elements is particularly preferably provided with a reflective or metallic or metallic reflective coating, so that the surface reflects the incident light almost mirror-like. This coating, which is applied to the substrate, is preferably carried out as follows: as a metallic or metallic-like screen printing ink, as a color with optically variable pigments, preferably so-called

OVI pigments, as a color with optically variable pigments which are additionally magnetically alignable, preferably so-called OVMI pigments,

as a color with optically variable iriodin pigments e.g. Bayer, which is applied in flexographic printing or screen printing and is preferably combined with a substrate applied in offset printing,

as a film in the form of a strip or patch applied to the substrate,

as a glossy offset ink, which preferably has a shiny metallic surface,

- As a glossy intaglio printing ink, which preferably has a black color or is colorless or may also have a shiny metallic appearance, such as gold or silver.

The substrate preferably comprises paper and / or a film, in particular a translucent film. In the simplest case, the substrate is completely made of either paper or plastic. However, the substrate can also be made of different materials in some areas, and in particular in a range of paper and at the same time in another area made of plastic, preferably from a translucent film exist. This makes it possible to emboss different materials as a substrate in one operation. Translucent film is here understood to mean either a transparent or a semitransparent film, for example a translucent film which contains, for example, polyamide, polyester, polyethylene or biaxially oriented polypropylene (BOPP).

According to a preferred embodiment, the embossing elements are introduced into a translucent film. For example, this translucent foil may at least partially cover an opening in an opaque value document. According to a preferred embodiment, at least a part of the non-linear embossing elements is arranged in a grid pattern. The nonlinear embossing elements are thus not stochastic at least in this subarea, but are arranged in a regular grid at a certain distance from one another.

According to a preferred embodiment, at least a part of the non-linear embossing elements is designed tactile detectable, so that the viewer not only visually recognize them but also can feel, for example, with the fingertips.

A particular advantage of the security element according to the invention is that it can not be imitated by comparatively simple techniques. In particular, its manufacture requires the use of a laser capable of producing exactly enough recesses in embossing plates to produce an embossing mold with a width to depth ratio of 2 to 1 (the so-called aspect ratio), a wider variety of geometries, and clear information content , The laser engraving is preferably carried out by means of an ultra-short pulse laser which emits laser pulses having a duration in the range of picoseconds or femtoseconds. Particularly preferred is a picosecond or ps laser is used which emits laser pulses with a duration in the range of picoseconds.

Likewise, the security element according to the invention for its production requires a very high mechanical pressure on the substrate to be embossed, without violating this by Papieran- or -durchschnitte. Preferably, the embossed structures are produced by means of the intaglio printing process, which is known from banknote printing and counterfeiters can not or only with considerable financial and technical effort can be imitated. Particularly preferably, the embossed structures on the flanks smoothly merge into one another, so that no injuries of the substrate can occur, such as the paper or paper averages mentioned in a paper substrate. In particular, the steepness of the embossed structures or their flanks influences the tear behavior of the substrate.

Further advantages of the security element according to the invention are that the security element is recognizable without aids for the user or the man on the street, it has a long-term stable embossing structure and can be used as a design means.

The engraving depth of the structures in an embossing plate for producing the embossing structures according to the invention is 20 m to 500 pm, preferably 30 pm to 255 pm and particularly preferably 50 pm to 130 pm. The height of the embossed structures that can be produced with such a stamping plate is dependent on the substrate in which the embossed structures are embossed. In the case of a cotton substrate, for example, the height of the embossed structures can be about 90% of the engraving depth and, for example, only 30% for a plastic substrate. The diameter of the embossed structures is from 30 pm to 2000 pm, preferably from 100 pm to 500 pm, and more preferably from 120 pm to 300 pm. The distance between individual embossed structures is 0 pm to 300 pm, preferably 0 pm to 50 pm, and particularly preferably 2 pm to 20 pm. The information generated by the embossed structures preferably consists of a combination of an alphanumeric indication, for example a value number "50", with a further graphical indication, for example a "€" symbol. In a first angular range, in which a viewer looks at the security element, the viewer sees the alphanumeric indication and in a second angle range the graphical indication.

Documents of value within the meaning of the present invention are, in particular, banknotes, stocks, bonds, certificates, vouchers, checks, high-quality admission tickets, but also other counterfeited papers, such as passports or other identification documents, and also card-shaped data carriers, in particular chip cards, as well as product security elements, such as labels , Seals, packaging and the like. The term "value document" also includes non-executable precursors of such data carriers, which, for example in the case of security paper, are available in virtually endless form and are processed further at a later time.

The advantages of the invention will be explained with reference to the following examples and additional figures. The described individual features and embodiments described below are inventive in their own right, but are also inventive in combination. The examples illustrate preferred embodiments, to which, however, the invention should not be limited in any way. The proportions shown in the figures do not correspond to the conditions present in reality and serve only to improve the clarity.

In detail, show schematically: 1a in each case with a partial cutout and in Fig. Lb with two partial cutouts, Fig. 2 is a knob-shaped embossing element of Fig. La in view obliquely from below (based on the figure of FIG in this case in FIG. 2 a without partial cutout, in FIG. 2 b with a triangular partial cutout and in FIG. 2 c with a trapezoidal partial cutout,

3 shows an arrangement of different embossing elements according to the invention in a security element, embossing elements according to the invention in plan view, each with a partial cutout, wherein the partial detail is rotated by 45 ° from FIG. 4d to 4d, an arrangement of different embossing elements according to the invention shown in FIG 4 in a security element for generating a movement effect,

Fig. 6 shows an arrangement of three different inventive

Embossing elements similar to Figure 4, wherein the outline results in each case the entirety of all embossing elements different illustrations,

7 shows three embodiments of basic shapes of embossing elements without partial cutout in knobbed form in oblique view from above, 8 shows three embodiments of embossing elements in the form of a truncated cone with a further additional information,

Fig. 9 embossing elements in the form of a truncated cone with variation of certain geometry parameters within a security element.

Fig. 1 shows exemplary advantageous embodiments of embossing elements according to the invention with a round base in plan view. The embossing elements are formed in this embodiment in the form of a "knob" or "knob-shaped", being understood as a knob in the context of this invention, a hump-like elevation on a surface (see also "Duden - German Universal Dictionary, 4th Edition, Dudenverlag, 2001 ). Each embossing element, which is described in this and the following exemplary embodiments, thus rises out of the paper surface in the shape of a pimple or hump, thus forming a three-dimensional and haptically detectable structure. However, a nub is not limited to only a round cross-sectional area. Rather, the base of a nub can take any shape, for example, in addition to round also three-, four- or polygonal and does not have to be symmetrical but can also be performed asymmetrically, elongated or bent.

In this case, FIG. 1 a shows two exemplary embodiments of nub-shaped embossing elements, each with a partial cutout in the lower region or the underside (with reference to the schematic representation of FIG. 1) of the embossing elements, wherein in the left-hand illustration an embossing element with a triangular partial cutout and is shown in the right figure with a square or trapezoidal cutout. The area shown in black represents the embossing element and the white area represents the partial section. The term "bottom" or "top", "bottom" or "top" and "bottom" and "top" of the embossing elements is here and below with reference to the schematic representation of the embossing elements in the figures. For example, the underside or the lower region of an embossing element thus does not designate the side which faces the substrate into which the embossing element is embossed, but rather a specific flank or side of the embossing element with reference to the schematic representation. Alternatively, the term "lower side" could be replaced by the term "southern side" or "northern side" instead of the term "upper side".

FIG. 1b shows two embodiments corresponding to FIG. 1a, each with an additional partial recess in the upper region of the embossing elements. If a viewer looks from obliquely down onto an embossing element, an additional information results, he looks obliquely from above on the embossing element, results in contrast to Fig. La further additional information.

1a shows an example of a nub-shaped embossing element from FIG. 1a in a view obliquely from below (with reference to the illustration of FIG. 1a) and in this case in FIG. 2a without partial cutout, in FIG. 2b with a triangular ("pie-shaped" 1a) and in FIG. 2c with a trapezoidal partial section according to the right-hand representation of FIG. 1a. The respective partial section is shown hatched.

Fig. 3 shows an advantageous embodiment with an arrangement of different embossing elements in a rechteckf örmigen security element, wherein the respective knob-shaped embossing elements contain different information. The entire security element has a uniform color by the embossed substrate is either not printed and thus the security element has the color of the substrate or by the substrate is printed with a uniform color, for example, with a shiny metallic color. In Fig. 3a, which shows the security element in plan view, the different information in different colors (white, gray, black) are shown for better illustration. In the upper left area of Fig. 3a, a plurality of embossing elements are shown, which show by way of example the arrangement of the knob-shaped embossing elements, as they are arranged on the entire security element. The nub-shaped embossing elements are in this case grid-like arranged in rows and columns.

FIGS. 3b to 3e show the plan view of the embossing elements of the respective regions with the different information from FIG. 3a.

Fig. 3b shows an embossing element of the field shown in white in Fig. 3a, this field containing no additional information, i. The field appears in almost all viewing angles in a uniform color. This field is formed by nub-shaped embossing elements, which have no recess and thus a completely circular base.

3a shows an embossing element of the field shown in black in FIG. 3a, this field showing in the outline a first additional information in the form of the number "1", which is recognizable only under a first viewing angle range formed by nub-shaped embossing elements, which have on their underside a trapezoidal recess. These nub-shaped embossing elements correspond to the nub-shaped embossing elements of Fig. La right representation and Fig. 2c. A flank of the partial recess casts a shadow on the opposite flank ke, which therefore appears darker within the first viewing angle range than the surrounding areas. In a viewing direction from a different than that of the first viewing angle range on the embossing element disappears the first additional information, ie the number "1".

3a shows an embossing element of the field shown in FIG. 3a in gray, this field showing in the outline a second additional information in the form of the letter "X", which is recognizable only under a second viewing angle range which is different from the first viewing angle range The letter "X" is formed by nub-shaped embossing elements, which have a trapezoidal recess on their upper side. The nubbf örmigen embossing elements correspond to the nub-shaped embossing elements of Fig. La right representation and Fig. 2c, which are rotated by 180 ° about its vertical axis. A flank of the partial recess casts a shadow on the opposite flank, which therefore appears darker within the second viewing angle range than the surrounding areas. In a direction of view other than that of the second viewing angle range on the embossing element, the first additional information, i. the letter "X".

Fig. 3e shows the area in which the first and second additional information overlap and overlap. In this area, the figure "1" can be seen in the first viewing angle range and the letter "X" in the second viewing angle range, wherein the embossing elements are shaped in accordance with the embossing pattern from FIG. 1b (right-hand representation). Thus, when tilting the security element along a tilt axis aligned parallel to the lower or upper edge of the security element, a viewer sees as viewed perpendicular to the security element an area in a uniform hue, such as a uniformly shiny silver surface ie only a nearly uniform surface without additional information,

within the first viewing angle range, the figure "1" in a hue darker than point 1., i.e., for example, in a dark silvery or dull silver surrounded by an area in a uniform hue, i.e., for example, in a uniform silver shining color;

within the second viewing angle range, the letter "X" in a hue darker than point 1, for example in a dark silver or dull silver color surrounded by a surface in a uniform hue, for example in a uniform silver glossy color,

wherein the numeral "1" and the letter "X" overlap in a subarea, so that in this subarea when viewed perpendicularly an area in a uniform hue, within the first viewing angle range the numeral "1" in a respect to 1. darker hue and Within the second viewing angle range, the letter "X" can be seen in a shade that is darker than point 1. FIG.

Fig. 4 shows an embossing element in plan view, which corresponds to an embossing element of Fig. La (left), wherein from Fig. 4a to Fig. 4d of the partial section by 45 ° with respect to the vertical axis of the embossing element is rotated further. Fig. 5 shows an arrangement of the embossing elements according to Fig. 4 in a security element, wherein each of the embossing elements of Figures 4a to 4d is arranged in a separate area with a triangular outline. The outline of each triangle rotates from left to right by 30 ° each.

When turning the security element about its vertical axis or the axis which is perpendicular to the plane of the security element, there is a movement effect, since from the respective viewing angle range of the corresponding embossing elements the differently rotated triangular outlines can be seen.

FIG. 6 shows an arrangement of three different embossing elements according to the invention similar to FIG. 4, wherein the outline results in different images around the entirety of all embossing elements. In the case of the upper embossing element, the outline gives a turtle, in the middle embossing element a butterfly and in the lower embossing element a fish, which can be recognized in each case from different viewing angle ranges.

Fig. 7 shows three embodiments of basic shapes of embossing elements without partial cutout in knob-like shape in oblique view from above. In the left figure, with a nearly semicircular cross-section at the top, tapered at the top, in the middle figure with a (semi-) egg-shaped cross section and in the right figure with a (semi-) egg-shaped cross-section torso with cut off or missing upper area.

Fig. 8 shows three embodiments of embossing elements in the form of a truncated cone with a further additional information. These additional additional Formation complements the first additional information, wherein the embossing elements 1 have on their top surface recesses 2 in the form of depressions, which can be seen by a viewer from a certain angle range. Fig. 9 shows embossing elements of a security element in the form of a truncated cone with variation of certain geometric parameters of the respective truncated cone. Here too, additional additional information advantageously complements the first additional information, wherein a viewer can recognize different embossing elements or groups of embossed elements from different angular ranges.

Thus, the height of the truncated cones varies in FIG. 9a, the diameter of the base areas and the diameter a of the cover areas remaining unchanged. In Fig. 9b, the opening angle of the truncated cones varies, wherein with unchanged height and base of the truncated cones, the top surface of a truncated cone or a first group of truncated cones diameter a and the top surface of another truncated cone or other group of truncated cones smaller diameter b.

In Fig. 9c also varies the opening angle of the truncated cones, wherein in this case varies with unchanged height and top surface of the truncated cones, the base of the truncated cones.

Claims

P a n t a n s p r e c h e

A security element having an optically variable structure, which has an embossed structure, wherein the embossing structure has a multiplicity of nonlinear, embossed embossing elements, wherein the optically variable structure has at least a first additional information, at least in a first subregion, which is obtained by varying the geometric shape of the embossing non-linear-shaped embossing elements by Abschattungseffek- te arises, characterized in that the at least one first additional information is formed by at least a partial section of the geometry of the respective non-linear embossed elements, so that the respective geometric shape of the non-linear embossing elements this at least a partial cutout missing ,

Security element according to claim 1, characterized in that the partial cutout has the shape of a triangle, a quadrangle, a polygon or an arcuate subsegment.

A security element according to claim 1 or 2, characterized in that the at least one first subregion has an outline shape which contains the at least one first additional information, wherein the at least one first additional information is visually recognizable to a viewer only under a first viewing angle range.

Security element according to one of the preceding claims, characterized in that in at least one second subregion of the optically variable structure at least one second additional information is formed by at least one partial detail of the geometry of the respective non-linear embossed elements, so that ometric shape of the non-linear shaped embossing elements of this at least one partial cutout is missing.

A security element according to claim 4, characterized in that the at least one second subregion has an outline shape which contains the at least one second additional information, wherein the at least one second additional information is visually recognizable to a viewer only under a second viewing angle range.

Security element according to one of the preceding claims, characterized in that at least a part of the non-linear embossing elements is arranged in a grid pattern.

Security element according to one of the preceding claims, characterized in that at least a part of the non-linear embossing elements is designed tactile detectable.

Security element according to one of the preceding claims, characterized in that at least a part of the non-linear embossing elements has substantially the shape of a tetrahedron, spherical section, truncated pyramid, cone, truncated cone, cylinder section, torus, oval, drop or a pyramid.

Security element according to one of the preceding claims, characterized in that the surface of the optically variable structure has a uniform color at least in the region in which the embossing elements are arranged.

10. A security element according to claim 9, characterized in that the security element consists of a substrate into which the embossing elements are embossed and which has a uniform color, wherein the hue of the surface of the optically variable structure corresponds to the hue of the substrate of the security element.

11. A security element according to claim 9, characterized in that on the surface of the optically variable structure an imprint or a coating is applied with a uniform hue.

12. A security element according to claim 11, characterized in that a reflective or metallic or metallic reflective coating, which is applied to the surface of the embossing elements, generates the uniform hue.

13. Tool for producing a security element according to one of claims 1 to 12.

14. Tool according to claim 13, characterized in that the tool is a printing or stamping plate.