Optical security element with effect region

Abstract

The invention relates to an optical security element (12) for protecting valuables, comprising at least two effect regions (14, 16) for producing different optical effects, the effect regions adjoining one another along a boundary line (18), and at least one of the two effect regions is formed by a micromirror region having a directional reflective micromirror. According to the invention, the boundary line (18) of the two effect regions is designed as a non-smooth edge such that a transition region (20) is formed in the two effect regions (14, 16) along the boundary line, in which transition region the optical effect of the first effect region (14) smoothly transitions into the optical effect of the second effect region (16) when viewed. The two effect regions may be formed from micromirror regions with directional reflective micromirror and different micromirror effects. One of the effect regions may be formed by a micromirror region with directional reflective micromirrors, and the other effect region may be formed by a diffractive relief structure (e.g., a hologram).

Description

[0001] The invention relates to an optical security element for protecting valuables, the optical security element having at least two effect areas for producing different optical effects. The invention also relates to a data carrier having such a security element and a method for producing such a security element.

[0002] Data carriers such as value documents or identification documents or other valuable articles such as brand-name goods are usually provided with a security element for protection against counterfeiting, which can verify the authenticity of the data carrier and at the same time serves to prevent unauthorized duplication.

[0003] In order to improve the anti-counterfeiting property of optical security elements, a combination of multiple different optical effects is usually used. If effect areas with different optical effects are adjacent to each other, a boundary line is therefore defined between these effect areas. For an observer, this boundary line can be used as a reference for register fluctuations that occur in other processes. Such fluctuations can have a stimulating effect on the observer. In addition to less visual appeal, the anti-counterfeiting property of optical security elements is also reduced, because counterfeits often have registration errors, and therefore, it is more difficult to reliably distinguish between originals and counterfeits in the case of registration fluctuations of the original.

[0004] Based on this, the technical problem to be solved by the present invention is to provide an optical security element of the type mentioned at the outset, which has a high degree of security against counterfeiting and an attractive visual appearance.

[0005] The technical problem is solved by the features of the independent claim. Developments of the invention are the technical solutions of the dependent claims.

[0006] The present invention provides an optical anti-counterfeiting element for protecting valuables, which has at least two effect areas for producing different optical effects, wherein the effect areas are adjacent to each other along a boundary line, and at least one of the two effect areas is composed of a micromirror area with directional reflective micromirrors.

[0007] Here, the boundary line of the two effect areas is designed as a non-smooth edge, so that a transition area is formed along the boundary line in the two effect areas, in which the optical effect of the first effect area smoothly transitions into the optical effect of the second effect area when observed. As a result, the optical security element has no clear boundary between the above-mentioned effect areas, so that there is no fixed reference point for the correct position of the (structural) feature generated in another process, for example, visually.

[0008] In an advantageous embodiment, the at least two effect regions are composed of micromirror regions with directional reflection micromirrors and different micromirror effects. In particular, one of the micromirror regions can be metallized, and the other micromirror region in the micromirror region can be non-metallized, for example, demetallized after metallization.

[0009] In a further, equally advantageous embodiment, one of the effect areas is formed by a micromirror area having directional reflecting micromirrors and another of the effect areas is formed by a diffraction relief structure, in particular a hologram, a holographic grating image or a hologram-like diffraction structure.

[0010] In all embodiments it can be advantageously provided that the micromirror region comprises a non-diffractive mirror and preferably a plane mirror, a concave mirror and / or a Fresnel-type mirror.

[0011] The borderline of the non-smooth edge is advantageously saw-cut, notched, toothed, lobed, cleft or wavy. Here, a borderline between two effect areas with a projection ending in a sharp angle and a notch ending in a sharp angle is called saw-cut, a borderline with a rounded projection and a notch ending in a sharp angle is called notched, a borderline with a projection ending in a sharp angle and a rounded notch is called toothed, and a borderline with a rounded projection and a rounded notch is called lobed, cleft or wavy, depending on the extent of the projection and notch extending into the adjacent effect area. Here, a larger extension of the projection or notch into the adjacent effect area of ​​more than 5 mm is called lobed, a medium extension of the projection or notch into the adjacent effect area of ​​0.5 mm to 5 mm is called cleft, and a smaller extension of the projection or notch into the adjacent effect area of ​​less than 0.5 mm is called wavy.

[0012] Advantageously, provision is made for the effect regions to merge into one another along a boundary line.

[0013] In an advantageous embodiment, it is provided that one of the effect regions forms an outer effect region which surrounds a further one of the effect regions which forms an inner effect region, and the boundary line is formed by the contour of the inner effect region.

[0014] In all embodiments, provision can advantageously be made for the boundary line of two effect areas to be designed as a non-smooth edge on a length scale below the resolution limit of the human eye.

[0015] In an advantageous embodiment, the boundary line of the non-smooth edge has a plurality of protrusions on a length scale below the resolution limit of the human eye, which protrusions have a clear change of direction. The width and spacing of the protrusions are advantageously below the resolution limit of the human eye, preferably below 150 μm, in particular below 100 μm.

[0016] In an advantageous embodiment, the elevations are arranged uniformly, in particular periodically, along the boundary line, wherein the period length is less than 300 μm, preferably less than 200 μm, particularly preferably between 10 and 100 μm.

[0017] In a further, likewise advantageous embodiment, the projections are arranged non-uniformly along the boundary line, preferably at varying intervals, the average value of which is less than 300 μm, preferably less than 200 μm, particularly preferably between 10 and 100 μm.

[0018] The height of the protrusion is preferably between 50 μm and 50 mm, preferably between 50 μm and 10 mm, particularly preferably above the resolution limit of the human eye and in particular between 0.5 mm and 5 mm. Correspondingly, the width of the transition region is preferably between 50 μm and 50 mm, preferably between 50 μm and 10 mm, particularly preferably above the resolution limit of the human eye and in particular between 0.5 mm and 5 mm.

[0019] The invention also includes a data carrier having an optical anti-counterfeiting element of the type described. The data carrier can be a valuable document, such as a banknote, in particular a paper banknote, a polymer banknote or a film composite banknote, or a stock, bond, certificate, gift certificate, check, seal, tax stamp, high-quality admission ticket, or a voucher, such as a credit card, bank card, cash payment card, authorization card, identity card or passport personal information page.

[0020] The security element can be present as a separate security element arranged on the data carrier to be protected, but can also be part of the data carrier to be protected itself.

[0021] The invention also comprises a method for producing an optical security element of the type described, wherein

[0022] - producing at least two effect regions for producing different optical effects on the carrier, the effect regions adjoining each other along a boundary line, wherein at least one of the two effect regions is formed by a micromirror region having directional reflective micromirrors, and

[0023] The boundary line of the two effect regions is designed as a non-smooth edge, so that a transition region is formed along the boundary line in the two effect regions, in which transition region the optical effect of the first effect region smoothly transitions into the optical effect of the second effect region when observed.

[0024] Further embodiments and advantages of the invention are described below with reference to the accompanying drawings, which are not shown to scale for the sake of greater clarity.

[0025] In the attached picture:

[0026] Figure 1A schematic diagram showing a banknote having a security element according to the invention, the security element having two effect areas adjoining one another along a border line;

[0027] Figure 2 (a) shows a detailed view of a security element according to the invention with a transition region with perfect alignment of the two effect regions, and (b) shows a detailed view of a security element not according to the invention without a transition region;

[0028] Figure 3 In (a) a detailed view of a security element according to the invention with a typical positional deviation of the effective region is shown, and in (b) a security element not according to the invention without a transition region is shown;

[0029] Figure 4 In the case of the security element according to the invention, transition areas between effect areas with boundary lines having non-smooth edges are shown;

[0030] Figure 5 In (a) and (b) two further transition regions of the security element according to the invention are shown; and

[0031] Figure 6 An anti-counterfeiting element is shown, wherein the first effect area is composed of a metallized micromirror area and the second effect area is composed of a demetallized micromirror area, wherein (a) shows the design specifications, (b) shows an anti-counterfeiting element without a transition area not according to the present invention as a comparative example, and (c) shows an anti-counterfeiting element with a transition area according to the present invention.

[0032] The invention will now be explained taking a security element for banknotes as an example. Figure 1 A schematic diagram of a banknote 10 with a security element 12 according to the invention is shown.

[0033] The security element 12 comprises two effect regions 14, 16 for producing different optical effects, which adjoin each other along a border line 18. In the present embodiment, the effect region 14 is formed by a micromirror region with directional reflective micromirrors, while the effect region 16 represents a hologram.

[0034] In particular, a transition region 20 is formed along the boundary line 18 in both effect regions 14 , 16 , in which transition region the optical effect of the first effect region 14 merges smoothly with the optical effect of the second effect region 16 when viewed.

[0035] The two different effect areas 14, 16 usually show certain register fluctuations compared to (structural) features produced in other processes, but these register fluctuations are masked by the transition area. As mentioned above, the problem with conventional designs is that register fluctuations reveal defects in the production process and visible position deviations of the effect areas can be irritating to the observer.

[0036] like Figures 2 to 5 As shown, these difficulties are overcome by providing a smooth, soft transition between the two effect areas 14, 16.

[0037] first, Figure 2 (a) shows a detailed view of a security element 12 with effect areas 14, 16 and a transition area 20 formed along a boundary line 18, ideally assuming that the two effect areas 14, 16 are perfectly aligned. In this case, the perfect alignment is such that, in the present embodiment, the boundary line 18 between the effect areas is exactly at the height of the structural feature 22 in accordance with the design specifications. For comparison, Figure 2 (b) shows a security element 12 ′ not according to the invention, which has no transition region and has an idealized perfect alignment of the boundary line 18 ′ relative to the structural feature 22 .

[0038] Figure 3 (a) shows a security element 12 with a typical position deviation Δ of the effect areas 14, 16 relative to the structural features 22, which occurs in real security elements due to unavoidable register fluctuations when producing the structural features 22 in a separate process step. For comparison, Figure 3 (b) shows a security element 12 ′ not according to the invention, which has no transition region and has the same position deviation Δ as the security element 12 .

[0039] Due to the design of the transition region 20 described in detail below, the optical effect of the first effect region 14 transitions smoothly there to the optical effect of the second effect region 16. Figure 2 (a) and Figure 3 The design according to the invention of (a) has no clear boundary between the two optical effects, so there is no visually fixed reference point for the correct position of the structural feature 22. Figure 2 (a) The idealized, perfectly aligned position and the basis Figure 3 The differences between the positions of (a) that typically occur in reality are very slight and not noticeable when observed.

[0040] In contrast, Figure 3In the comparative security element 12 ′ of (b), the incorrect alignment of the clear border line 18 ′ relative to the structural feature 22 is clearly perceptible due to the clearly perceptible position of the border line 18 ′ and leads to the above-mentioned disadvantageous effects.

[0041] Reference Figure 4 The transition region 20 between the two effect regions 14 and 16 is produced in such a way that the boundary line 18 of the two effect regions is designed as a non-smooth edge along the boundary line on a length scale that cannot be perceived by the naked eye. Figure 4 In the embodiment of the invention, the boundary line 18 is designed to be saw-cut and has a sawtooth structure with many fine sharp teeth 32, the width of which is less than 100 μm and thus below the resolution limit of the human eye. The height H of the sharp teeth 32 is substantially consistent with the required width of the transition region 20 and can be, for example, 0.5 mm or a few millimeters.

[0042] Due to the sharp-toothed design of the boundary line 18, the surface area share of the first effect region 14 decreases continuously from 100% to 0% at the height H of the sharp-toothed teeth 32 in a direction 30 perpendicular to the boundary line 18, while at the same time, the surface area share of the second effect region 16 increases continuously from 0% to 100%. As a result, the two effect regions 14, 16 merge into one another along the boundary line 18.

[0043] The sawtooth structure of the border line 18 can advantageously be regular, i.e. have sharp teeth of the same size and equal spacing, but can also be designed to be irregular, such as in Figure 4 As shown in the embodiments.

[0044] Figure 5 Two further embodiments of the security element according to the invention are shown. Figure 5 In the design of (a), the boundary line 18 between the effect areas 14, 16 is formed with a protrusion / cut 34 that is rounded in both directions. As mentioned above, this shape of the boundary line 18 is called a lobed, semi-cleft or corrugated shape, depending on the size of the protrusion or cut extending into the adjacent effect area.

[0045] Figure 5 The border line 18 of (b) has a mixed shape, wherein the protrusion / cutout 36 ends in a sharp angle toward the effect area 14 and is rounded toward the effect area 16. From the viewing direction of the effect area 14, this design is called a notch (sharp cutout, round protrusion), and from the viewing direction of the effect area 16, this design is called a toothed shape (round cutout, sharp protrusion).

[0046] exist Figure 5 3 and 4. The irregular arrangement of the protrusions or cutouts 34 and 36 is also shown in FIG. 3, but it is self-evident that the protrusions and cutouts can also be arranged regularly in the same shape and at the same intervals along the boundary line.

[0047] Also in Figure 5 In the design, in the transition region 20, the area share of the first effect region 14 continuously decreases from 100% to 0% at the height of the protrusions or cutouts 34, 36, while at the same time, the area share of the second effect region 16 continuously increases from 0% to 100%, so that the optical effect of the first effect region 14 smoothly transitions to the optical effect of the second effect region 16 in the transition region 20.

[0048] Figure 6 A security element according to a further embodiment of the invention is shown, in which the first effect region is formed by a metallized micromirror region 54 and the second effect region is formed by a demetallized micromirror region 56. The two effect regions 54, 56 also exhibit different micromirror effects.

[0049] To illustrate, Figure 6 (a) shows the design specifications of an idealized star-shaped demetallization 46 within the surrounding metallization area 44 . Figure 6 (b) shows as a comparative example a security element 52' not according to the invention which has no transition region, ie has a sharp boundary 58' and a certain register fluctuation of the demetallized portion 56' within the metallized region 54'. Figure 6 As can be seen in (b), due to the irregular star shape and the clearly defined boundary 58', the observer can clearly perceive the presence of registration fluctuations.

[0050] at last, Figure 6 (c) shows a security element 52 according to the present invention, wherein the boundary line between the demetallized micromirror region 56 and the metallized micromirror region 54 is formed as a non-smooth edge along the boundary line of the two micromirror regions on a length scale that cannot be distinguished by the naked eye.

[0051] For example, Figure 4 As shown, the borderline can have a sawtooth structure with many fine sharp teeth. Therefore, in the transition area 60, the thickness of the metallization portion decreases continuously from 100% to 0% along a direction perpendicular to the local orientation of the borderline from the outside, that is, from the fully metallized effect area 54 to the inside, that is, to the fully demetallized effect area 56. Of course, the borderline can also be formed in a notch-like, tooth-like, shallow crack-like, half-crack-like or corrugated shape.

[0052] In this way, a soft, smooth transition between the metallized area 54 and the demetallized area 56 is achieved, which masks the presence of register fluctuations, such as Figure 6 (c) as shown.

[0053] Reference numerals list

[0054] 10 banknotes

[0055] 12 Anti-counterfeiting elements

[0056] 12' Comparison Example

[0057] 14, 16 Effect Area

[0058] 18 Border Line

[0059] 18'Borderline in the comparison example

[0060] 20 Transition Zone

[0061] 22Structural features

[0062] 30 Direction perpendicular to the boundary line

[0063] 32 sharp teeth

[0064] 34, 36 bulge

[0065] 44 Metallization Areas in Design Specifications

[0066] 46 Demetallization in the design specification

[0067] 52 Anti-counterfeiting elements

[0068] 52' Comparison Example

[0069] 54 metallized micromirror area

[0070] 54'Metalized area in the comparative example

[0071] 56Demetallized micromirror area

[0072] 56' Demetallization section in comparative example

[0073] 58' Clearly defined boundaries in the comparison example

[0074] 60 Transition Area

Claims

1. An optical anti-counterfeiting element for protecting valuables, the anti-counterfeiting element having at least two effect areas for producing different optical effects, wherein: The effect regions are adjacent to each other along a boundary line, and at least one of the two effect regions is composed of a micromirror region having directional reflection micromirrors, It is characterized in that The boundary line of the two effect regions is designed as a non-smooth edge, so that a transition region is formed along the boundary line in the two effect regions, in which the optical effect of the first effect region smoothly transitions into the optical effect of the second effect region when observed.

2. The optical anti-counterfeiting element according to claim 1, characterized in that: The at least two effect regions are composed of micromirror regions having directional reflection micromirrors and different micromirror effects.

3. The optical anti-counterfeiting element according to claim 2, characterized in that: One of the micromirror regions is metallized and the other of the micromirror regions is non-metallized, in particular demetallized.

4. The optical anti-counterfeiting element according to claim 1, characterized in that: One of the effect regions is formed by a micromirror region having directionally reflective micromirrors, and the other of the effect regions is formed by a diffractive relief structure, in particular a hologram, a holographic grating image or a hologram-like diffractive structure.

5. The optical security element according to at least one of claims 2 to 4, characterized in that The micromirror region or the plurality of micromirror regions each contain a non-diffractive mirror and preferably a plane mirror, a concave mirror and / or a Fresnel-type mirror.

6. The optical security element according to at least one of claims 1 to 5, characterized in that Non-smooth edge borders are saw-cut, notched, jagged, lobed, cleft, or wavy.

7. The optical security element according to at least one of claims 1 to 6, characterized in that The effect areas merge into each other along the border lines.

8. The optical security element according to at least one of claims 1 to 7, characterized in that One of the effect regions forms an outer effect region which surrounds another of the effect regions which forms an inner effect region, and the boundary line is formed by the contour of the inner effect region.

9. The optical security element according to at least one of claims 1 to 8, characterized in that The boundary line of the two effect areas is designed as a non-smooth edge on a length scale below the resolution limit of human eyes.

10. The optical security element according to at least one of claims 1 to 9, characterized in that The boundary line of the non-smooth edge has a plurality of protrusions on a length scale below the resolution limit of human eyes, and the protrusions have clear direction changes.

11. The optical anti-counterfeiting element according to claim 10, characterized in that: The width and the spacing of the protrusions are below the resolution limit of the human eye, preferably below 150 μm, in particular below 100 μm.

12. The optical anti-counterfeiting element according to claim 10 or 11, characterized in that: The elevations are arranged uniformly, in particular periodically, along the boundary line, wherein the period length is less than 300 μm, preferably less than 200 μm, particularly preferably between 10 μm and 100 μm, or The projections are arranged non-uniformly along the boundary line, preferably at varying intervals, the average value of which is less than 300 μm, preferably less than 200 μm, particularly preferably between 10 μm and 100 μm.

13. The optical security element according to at least one of claims 1 to 12, characterized in that The height of the elevations is between 50 μm and 50 mm, preferably between 50 μm and 10 mm, particularly preferably above the resolution limit of the human eye and in particular between 0.5 mm and 5 mm.

14. The optical security element according to at least one of claims 1 to 13, characterized in that The width of the transition region is between 50 μm and 10 mm, preferably above the resolution limit of the human eye and in particular between 0.5 mm and 5 mm.

15. A data carrier comprising the optical security element according to any one of claims 1 to 14.

16. A method for producing an optical security element according to any one of claims 1 to 14, wherein - producing at least two effect regions for producing different optical effects on the carrier, which effect regions adjoin one another along a boundary line, wherein: At least one of the two effect regions is composed of a micromirror region having directional reflective micromirrors, and The boundary line of the two effect regions is designed as a non-smooth edge, so that a transition region is formed along the boundary line in the two effect regions, in which transition region the optical effect of the first effect region smoothly transitions into the optical effect of the second effect region when observed.

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