Security element and value document having said security element

Abstract

A value document having a security element in the form of a strip with a first polymer layer which comprises at least one embossed diffraction structure, having at least one reflection layer which visually interacts with the diffraction structure in order to form a reflection hologram as the first visually recognisable security feature, and having at least one imprint which is luminescent under UV radiation and which forms a second security feature that is visually recognisable under UV light, wherein the reflection hologram comprises at least one see-through region on the second security feature. In order to increase the level of protection against forgery of the security element, the luminescent imprint comprises a halftone print image, and the see-through region is formed by at least one recess in the reflection layer and by the polymer layer which is free in this region of the recess from the diffraction structure at least above the halftone print image of the imprint.

Claims

1. A security element in the form of a strip, comprising: a polymer layer having at least one embossed diffraction structure; at least one reflection layer which optically interacts with the at least one diffraction structure in order to form a reflection hologram as a first visually recognisable security feature; and at least one imprint which is luminescent under UV radiation and which forms a second security feature that is recognisable under UV radiation, the at least one luminescent imprint comprising a halftone print image, wherein the reflection hologram comprises at least one see-through region revealing the second security feature, and at least one recess in the at least one reflection layer and the polymer layer together form the at least one see-through region, wherein the polymer layer is free from the at least one diffraction structure in the at least one recess, at least above the halftone print image of the imprint.

2. A security element according to claim 1, wherein the at least one diffraction structure and the at least one reflection layer are aligned in relation to each other in register.

3. A security element according to claim 1, wherein the at least one recess and the halftone print image are aligned in relation to each other in register.

4. A security element according to claim 1, wherein the at least one reflection layer covers a boundary contour of the halftone print image at least in sections.

5. A security element according to claim 1, wherein the at least one recess is provided in the form of a character, pattern or coding in the at least one reflection layer.

6. A security element according to claim 1, wherein the reflection hologram comprises a motif and the at least one recess forms a motif part of the reflection hologram.

7. A security element according to claim 1, wherein for forming a multicolour luminescent imprint the halftone print image comprises halftone dots which are luminescent with different colours selected from the group consisting of red, green and blue.

8. A security element according to claim 7, wherein the halftone print image comprises a honeycomb grid, whose hexagonal grid cells consist of triangular halftone dots which are arranged adjacent to each other and bordering each other.

9. A security element according to claim 7, wherein the halftone prim image comprises grid cells with a size of 10 to 500 m.

10. A security element according to claim 1, wherein the security element comprises a transparent topcoat layer that is an adhesive layer.

11. A security element according to claim 1, wherein the security element comprises a transparent cover film.

12. A security element according to claim 1, wherein the security element comprises a carrier film formed as a transfer carrier.

13. A value document with a substrate and with at least one security element according to claim 1 provided on the substrate.

14. A value document according to claim 13, wherein the luminescent imprint is visually adjusted to match a visual appearance of the substrate.

15. A value document according to claim 13, wherein the security element is embedded in the substrate, and the substrate comprises at least one window for viewing the security element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject matter of the invention is shown in closer detail in the drawings by reference to an embodiment, wherein:

(2) FIG. 1 shows a cross-sectional view through an embodiment of the security element in accordance with the invention;

(3) FIG. 2 shows a cross-sectional view through a value document with a further embodiment of the security element;

(4) FIG. 3 shows a cross-sectional view through a further value document with a third embodiment of the security element, and

(5) FIG. 4 shows a top view of a security element in accordance with the invention with a detailed view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) FIG. 1 shows a security element 100, on which a polymer layer 2, especially a polymerized lacquer layer, is provided. A diffraction structure 3 is embossed in the polymer layer 2, which diffraction structure 3 forms a reflection hologram 5 with a reflection layer 4 provided on the polymer layer 2, which reflection hologram represents the first security feature of the security element 100. An imprint 6 is further applied, which is luminescent under radiation with UV-light. The imprint 6 especially contains luminescent dyes for this purpose. Recesses 7 are provided above the imprint 6 in the reflection layer 4.

(7) The highest level of security is achieved on the security element 100 in accordance with the invention in such a way that the see-through region 8 is formed by at least one recess 7 in the reflection layer 4 and by the polymer layer 2 which is free from the diffraction structure 3 in this region of the recess 7. Only this allows perceiving without distortions a luminescent imprint 6 with a halftone print image 60 which comprises isotropic fluorescent radiation. For this purpose, the recess 7 is provided at least over the halftone print image 60 of the imprint 6, as shown in FIG. 4. This ensures unlimited viewing of the halftone print image 60. The security element 100 can thus be viewed both from the side of the carrier film 1 and also from the side of the imprint 6, thus creating a security element 100 with a high level of protection against forgery.

(8) FIG. 1 further shows that the diffraction structure 3 embossed in the polymer layer 2 ends on the recess 7 of the reflection layer 4. No diffraction structures 3 are introduced into the see-through regions 8 in the first polymer layer 2, so that unobstructed viewing (e.g. an unchanged visual impression of the imprint 6) can be achieved, even in the boundary region. It can thus be prevented that a visual superposition between the diffraction structure 3 and the luminescent imprint 6 occurs in the boundary regions of the see-through regions 8. Furthermore, the imprint 6 is in the register with the see-through region 8 or the recess 7 in the reflection layer 5. For this purpose, the diffraction structure 3 and the reflection layer 4 are advantageously also arranged in the register with respect to each other. The boundary contour 9 of the reflection layer 4 can also slightly cover the boundary contour 10 of the halftone print image 60, i.e. the halftone image 60 can thus also extend minimally beyond the reflection layer 4 behind the diffraction structure 3. This leads to a sharp boundary contour between the luminescent imprint 6 and the reflection hologram 5. It is also possible, as shown in FIG. 2, that the boundary contour 10 of the halftone print image 60 is not covered by the boundary contour of the reflection layer 4 but lies in the region of the recess 7. Visual impairments in the visual perceptibility of the halftone print image 60 can thus be prevented.

(9) As is shown especially in FIG. 4, the halftone print image 60 comprises luminescent halftone dots 61, 62, 63 which have different colours, namely red, green and blue. This leads to a halftone print image 60 which is luminescent in true colour. Furthermore, the halftone print image 60 comprises a honeycomb grid 64, whose hexagonal grid cells 65 consist of triangular points 61, 62, 63 which are arranged adjacent to each other. Said grid cells 65 have a size of 10 to 500 m, especially 50 to 200 m.

(10) Furthermore, the boundary contour 9 of the recess 7 in the reflection layer 4 can follow the shape of a character, a pattern or a coding. It has proved to be especially advantageous if the boundary contour 9 of the recess follows or completes a motif generated by the reflection hologram 5. As a result, different motif parts can be recognised under different illumination situations.

(11) The imprint 6 is advantageously covered by a transparent topcoat layer 11, as shown in FIG. 1. The topcoat layer 11 can be formed as a transparent protective lacquer 11, or as an adhesive layer 11, especially as a hot-seal lacquer layer 11. It can also be considered that both a transparent protective lacquer and also the adhesive layer form the topcoat layer 11. Security elements 100, 101, 102 in accordance with the invention can be provided on value documents 201, 202 above the adhesive layer 11, as shown in FIG. 2 and FIG. 3.

(12) A transparent cover film 12 can further be attached to the adhesive layer 11 of the security element 100, 101, 102, as is shown for example in the security element 102 represented in FIG. 3.

(13) In a further embodiment, the polymer lacquer layer 2 is advantageously attached by way of adhesion to a carrier film 1. Such a carrier film 1 can both facilitate the production process of the security element 100, 101, 102, and also improve the stability thereof. Alternatively, the carrier film 1 or the transfer carrier 1 can be provided to be detachable from the polymer lacquer layer 2.

(14) Value documents 201, 202 are shown in FIG. 2 and FIG. 3, wherein a respective security element 101 or 102 is applied to the value documents 201, 202. The value documents 201, 202 can especially concern a banknote, a driver's license, an ID card, a passport or comparable documents in accordance with the invention.

(15) FIG. 2 shows a value document 201, wherein the carrier film 1 (see FIG. 1) was removed from the applied security element 101. The security element 101 was glued by the adhesive layer 11 onto the substrate 13 of the value document 201. The luminescent imprint 6 is visually adjusted to the visual appearance of the substrate 13 of the value document 201.

(16) The value document 202 shown in FIG. 3 comprises a security element 102, onto which a transparent cover film 12 was applied. The security element 102 is embedded between an upper substrate 14 and a bottom substrate 15. Both the upper substrate 14 and also the bottom substrate 15 comprise windows 16 in order to allow direct view at least in part onto the security features of the security element 102. An additional adhesive layer 17, especially a hot-seal lacquer layer, is provided between the security element 102 and the substrate 14, 15 of the value document 202, which are also left open in the region of the windows 16. The carrier film 1 and the transparent cover film 12 of the security element 102 can further be formed to be printable. It can be considered that a print 18, with or without luminescent dyes, is provided in each case on the carrier film 1 and the cover film 12.

(17) In another embodiment of the invention, only one of the substrates 13, 14 has a window 16, which was not shown in detail in the figures.

(18) In addition, in a further embodiment, a value document is created which has a security element 100, 101, 102 which is in accordance with the invention and which is applied to a single substrate 13, wherein the substrate 13 has a window for viewing the security element 100, 101, 102, which, however, is not described in detail in the figures. Such a security element can thus be viewed from two sides and thus increase the protection against forgery.