Abstract
The invention relates to a security element for application to a surface of a valuable document or at least partial embedding into a substrate of the valuable document, for example a banknote or a passport, wherein the security element consists of a plastics film. According to the invention, at least one printing ink which is transparent in the infrared wavelength range of electromagnetic radiation (referred to hereinafter as IR-transparent printing ink) and has a first reflectance value and at least one printing ink which is absorbent in the infrared wavelength range of electromagnetic radiation (referred to hereinafter as IR-absorbing printing ink) and has a second reflectance value are applied to the plastics film of the security element, the separation between the first and second reflectance values being at least 40%.
Claims
1.-5. (canceled)
6. A security element for application onto a surface of a document of value or at least partial embedding into a substrate of the document of value, for example a bank bill or a passport, the security element consisting of a plastic film, wherein at least one printing ink that is transparent in the infrared wavelength range of electromagnetic radiation (referred to below as an IR-transparent printing ink), having a first remission value, and at least one printing ink that is absorbent in the infrared wavelength range of electromagnetic radiation (referred to below as an IR-absorbent printing ink), having a second remission value, are applied onto the plastic film of the security element, the difference between the first and second remission values being at least 40%.
7. The security element as claimed in claim 6, wherein the at least one IR-transparent printing ink has a first remission value of >90% and the at least one IR-absorbent printing ink has a second remission value of <50%.
8. The security element as claimed in claim 6, wherein the difference of at least 40% between the first and the second remission value, or the remission values of the IR-transparent and IR-absorbent printing inks, exists only during the printing process, or for a freshly printed security feature, and printing inks does not fall below 20% throughout the entire circulation of a document of value.
9. The security element as claimed in claim 6, wherein the at least one IR-transparent printing ink and the at least one IR-absorbent printing ink are a solvent-based, water-based or UV-curable printing ink, or toner, which are printed onto the plastic film of the security element by intaglio printing, digital printing, UV offset printing, screen printing, inkjet printing or flexographic printing.
10. The security element as claimed in claim 6, wherein the at least one IR-transparent printing ink and the at least one IR-absorbent printing ink have the same coloring under illumination with visible electromagnetic radiation.
Description
[0035] The advantages of the invention will be explained with the aid of the following exemplary embodiments and the appended figures. The exemplary embodiments represent preferred embodiments, although the invention is in no way intended to be restricted to them. Furthermore, for the sake of better understanding, the representations in the figures are highly schematized and do not reflect the true situation. In particular, the proportions shown in the figures do not correspond to the ratios existing in reality and serve only to improve clarity. Furthermore, the embodiments described in the following exemplary embodiments are reduced to the essential core information for the sake of better comprehensibility. In practical implementation, substantially more complex patterns or images may be used.
[0036] In detail:
[0037] FIG. 1 schematically shows a side view of a security element according to the invention according to a first exemplary embodiment,
[0038] FIG. 2 schematically shows a side view of a security element according to the invention according to a second exemplary embodiment,
[0039] FIG. 3 schematically shows a side view of a security element according to the invention according to a third exemplary embodiment,
[0040] FIG. 4 schematically shows a side view of a security element according to the invention according to a fourth exemplary embodiment,
[0041] FIG. 5 schematically shows a side view of a security element according to the invention according to a fifth exemplary embodiment,
[0042] FIG. 6 schematically shows a side view of a security element according to the invention according to a sixth exemplary embodiment,
[0043] FIG. 7 schematically shows a side view of a security element according to the invention according to a seventh exemplary embodiment,
[0044] FIG. 8 schematically shows a plan view of a security element according to the invention according to an eighth exemplary embodiment,
[0045] FIG. 9 schematically shows a plan view of a security element according to the invention according to a ninth exemplary embodiment,
[0046] FIG. 10 schematically shows a plan view of a security element according to the invention according to a tenth exemplary embodiment.
[0047] FIG. 1 schematically shows a side view of a security element according to the invention according to a third exemplary embodiment. Two infrared-transparent printing inks 2 and 3 and two infrared-absorbent printing inks 4 and 5 are printed onto a substrate 1, for example a PET film, on one of its sides. The printing inks 2, 3, 4 and 5 are in this case printed at a certain distance from one another. The printing inks 2, 3, 4 and 5 may of course be printed directly next to one another and therefore without a distance from one another, as is shown in FIG. 2.
[0048] According to FIG. 3, the infrared-absorbent printing inks 4 and 5 may also be printed onto the opposite side of the substrate 1.
[0049] FIG. 4 schematically shows a side view of a security element according to the invention according to a fourth exemplary embodiment, in which an infrared-transparent printing ink 2 is printed fully over an infrared-absorbent printing ink 4 on one side of the substrate 1. According to FIG. 5, the printing inks 2 and 4 may also be printed congruently on opposite side of the substrate 1. Of course, only a partial overlap of the printing inks 2 and 4 is also possible in the exemplary embodiments mentioned above and below.
[0050] FIG. 6 schematically shows a side view of a security element according to the invention according to a sixth exemplary embodiment, in which an infrared-transparent printing ink 2 is printed fully over two infrared-absorbent printing inks 4 and 5 on one side of the substrate 1. According to FIG. 7, the printing inks 2, and 4 and 5, may also be printed congruently on opposite side of the substrate 1.
[0051] FIG. 8 shows a plan view of a security element according to the invention according to an eighth exemplary embodiment, in which an infrared-absorbent printing ink 4 is printed fully over an infrared-transparent printing ink 2 on one side of a substrate (not represented). The infrared-transparent printing ink 2 in this case forms the information of a five-pointed star, and the infrared-absorbent printing ink 4 forms the information of a circle which is arranged centrally inside the five-pointed star. Under illumination with visible electromagnetic radiation, or light with a wavelength of from about 380 nm to about 750 nm, an observer perceives both the star and the circle, left image in FIG. 8. Under illumination with electromagnetic radiation in the infrared wavelength range, the observer perceives only the circle, right image in FIG. 8.
[0052] FIGS. 9 and 10 show a plan view of a security element according to the invention according to a ninth and tenth exemplary embodiment, in which the words “ID” and “PASS” are printed with an infrared-absorbent printing ink and the word “PORT” and the separating symbols, or spaces, are printed with an infrared-transparent printing ink on one side of a substrate (not represented). The individual letters are printed as negative motifs with a light script against a dark background in FIG. 9, and as positive motifs with a dark script against a light background in FIG. 10. Under illumination with visible electromagnetic radiation, an observer perceives the entire lettering “ID PASSPORT”, in each case the upper image. Under illumination with electromagnetic radiation in the infrared wavelength range, the observer perceives only the lettering “ID PASS”, in each case the lower image.
