Exemplary embodiments of the invention are explained in more detail below with reference to the drawing, in which:
FIG. 1 schematically shows a section through a data carrier with a security element according to the invention,
FIG. 2 schematically shows a section through a data carrier with a security element in accordance with one variant,
FIG. 3 schematically shows a section through a data carrier with a security element in accordance with a further variant,
FIG. 4 shows a plan view of a line filter, and
FIG. 5 schematically shows a section through a security element for illustrating the relationship between the Moiré resolution and the distance between the filter and the band Moiré pattern.
FIG. 1 schematically shows a data carrier 1, which is for example a credit or identification card, an identity card or a so-called data page in a passport or some other document. The data carrier 1 has a substrate 2, which is for example a film composed of plastic, for example polycarbonate, or some other suitable material. A layer 3 is connected to the substrate 2, for example by the layer 3 being laminated onto the substrate 2. The layer 3 is fixedly and preferably inseparably connected to the substrate 2. The layer 3 may likewise be in monolayer or multilayer form. It is transparent at least in the region of a security element 7. The layer 3 has a top side 4, to which can be applied, in principle, a further transparent layer or a transparent lacquer or the like (not shown here). The said top side 4 is preferably parallel to an underside 6 of the substrate 2.
The security element 7 comprises a band Moiré pattern 10 or a customary Moiré pattern, which is arranged on a top side 5 of the substrate 2 or at an underside of the layer 3, and a filter 12, which is a line filter, in particular. The filter 12 is arranged at a distance from the band Moiré pattern 10 above the latter, as shown in FIG. 1. In accordance with FIG. 4, it comprises opaque lines 14 and transparent likewise linear parts 15. The opaque lines 14 have a comparatively very high opacity and are applied on the top side 4, for example by means of an analogue printing method, in particular screen printing or offset printing, or for example a digital printing method. The lines may also be inserted as additional elements between the substrate 2 and the layer 3. In accordance with FIG. 4, the opaque parts 14 and the transparent parts 15 may be straight parts that are parallel to one another, but they may also be formed as other forms that can be described mathematically, such as, for example, circles or spirals or wavy lines. The distances between the opaque parts 14 of the filter are identical in this case, however.
The band Moiré pattern 10 is printed onto the top side 5 of the substrate or is printed onto the underside 6 of the layer 3 or is inserted between the substrate 2 and the layer 3. For disclosure with regard to the formation and production of the band Moiré pattern, reference is made to the said two documents. In the case of the present invention, however, the said band Moiré pattern 10 is not viewed through an applied film, but rather through the filter arranged fixedly and at a distance with respect to the band Moiré pattern 10. The band Moiré pattern 10 contains an image or a subject which is inherently concealed and becomes visible through the filter 12. If the data carrier 1 is tilted, then the said image moves continuously. By way of example, the data carrier 1 may be tilted in such a way that the viewing direction changes from line L1 to line L2. Upon viewing in the direction of line L1, for example an image A (not shown here) becomes visible here, while upon viewing in the direction of line L2, an image B (not shown here) is visible. Upon changing from one direction to the other, the pattern moves continuously from the position A to the position B. The optical effect thus differs significantly from the flip effect known per se, in which either an image A or an image B is visible. Consequently, upon tilting, a fluid or continuous transition takes place in the case of the security element 7. In order for this to be possible, the arrangements shown in FIG. 5 are necessary. In the case of a viewing angle of 90°, which is indicated by the two arrows 17 and 18 in FIG. 5, a third of a Moiré tile period should be visible to a viewer 19. In this case, the said third corresponds to 2r and the Moiré tile period corresponds to 6r. A third is a guide value in this case since the optical effect is also dependent on the Moiré design. The distance h between the band Moiré pattern 10 and the filter 12 is also significant. If the said distance h is 0.1 mm, then it is equal to 0.1 mm. Since it is a sixth of the baseband period, the baseband period here is therefore at most 0.6 mm in order to obtain a good optical effect. The baseband period (also called Moiré tile period) denotes the height of the patterns repeating in a band Moiré pattern. A band Moiré pattern image comprises repeating identical patterns. The smaller the distance h, the finer the band Moiré pattern 10 should be in order to obtain a satisfactory optical effect. The distance h is at least 0.025 mm and preferably at least 0.05 mm. Preferably, the distance h is 0.1 mm or greater.
FIG. 2 shows a data carrier 1′, likewise having a substrate 2′ and a layer 3′. The layer 3′ is likewise fixedly connected to the substrate 2′, for example by lamination. The filter 12 may be formed in a manner identical to that mentioned above. The filter 12 is here in particular also a line filter, which was applied to the layer 3′ by means of a screen printing or offset printing method, by way of example. The data carrier 1′ has a security element 8 provided with a band Moiré pattern 11, which was produced by means of a laser only subsequently after the connection of the later 3′ to the substrate 2′. In order that the band Moiré pattern 11 can be produced by means of a laser, the filter 12 is formed in such a way that it is laser-transmissive. This likewise applies to the layer 3′. The substrate 2′ is produced from a laserable material. Such materials are known per se and become discoloured upon the impingement of laser beams. For this security element, the effect and the conditions are similar or identical to those explained above with reference to FIGS. 1 and 5. An essential advantage of this security element 8 is that the latter can be produced individually and on a personal basis. The band Moiré pattern 11 may contain for example an identification number or some other personal indication of the owner of the data carrier 1′. The band Moiré pattern 11 is preferably not produced until when the data carrier 1′ is personalized. At the same time, further data may also be applied outside the security element 8, for example may be printed on or likewise applied by means of a laser. Consequently, the data carrier 1′ is first produced only with the filter 12. Consequently, a semifinished product is produced which does not yet contain the band Moiré pattern 11. The said semifinished product can be stored until the data carrier 1′ is personalized and, in particular, the band Moiré pattern 11 is created by means of a suitable laser apparatus in the manner mentioned.
FIG. 3 shows a data carrier 1″ having a substrate 2″ and a layer 3″. The data carrier 1″ is provided with a security element 9 comprising a band Moiré pattern 16 and a filter 13. The band Moiré pattern 16 may be formed identically to the pattern 10 or 11 and is therefore likewise integrated into the data carrier 1″. The layer 3″ is likewise transparent and may be in monolayer or multilayer form. The filter 13 in this case is formed as a lens structure. The latter may be embossed onto the top side of the layer 3″ either directly during the lamination of the layer 3″ or in a subsequent embossing method. As can be seen, the filter 13 is applied to a partial region of the top side of the layer 3″, to be precise above the band Moiré pattern 16. Consequently, the filter 13 does not extend over the entire top side as is the case for the known flip images. In this case, too, the filter 13 is integrated directly into the data carrier 1″. In this case, too, a fluid movement of an image becomes visible when the data carrier 1″ is tilted. Here, too, the conditions are essentially identical to those explained above with reference to FIGS. 1 and 5.
LIST OF REFERENCE SYMBOLS
1 Data carrier
2 Substrate
3 Layer
4 Top side
5 Top side (substrate)
6 Underside (substrate)
7 Security element
8 Security element
9 Security element
10 Moiré pattern
11 Moiré pattern
12 Line filter
13 Lens grid
14 Opaque part
15 Transparent part
16 Moiré pattern
17 Arrow
18 Arrow
19 Viewer
- h Distance
- r Half visible part of the Moiré tile period
- L1 Line
- L2 Line
Patent Application
20070279697
