DE4343387A1 - Visually identifiable, optical security element for documents of value - Google Patents

Description

The invention relates to visually identifiable, optical Security elements for documents of value e.g. B. banknotes official credit cards, ID or check documents, or other objects to be secured, which have at least two Adjacent, differently structured when illuminated appearing, identifiable with the unarmed eye Include sub-areas.  

Such optical security elements that you Appearance depending on the viewing angle or the Changing lighting conditions are mostly for Credit cards, but also known for other areas of application. So far, the effort has gone in one Security element as many different optical as possible Effects, e.g. B. color changes, motion effects, holographic Effects, three-dimensional manifestations etc., in one Summarize motive to counterfeit the To make the security element as difficult as possible. this has however, the disadvantage that such a security element due to its unspecific appearance, especially for the Layperson and under the conditions, for example, of Payment transactions where lighting conditions are unfavorable prevail and only a very short exam time is available is not verifiable for authenticity. With such known optical security elements (so-called. OVD's) can thus actually falsifying the security elements become more difficult; a reliable check for authenticity is however only with appropriate devices or large visual examination effort, but not easily in the Fast possible by a layperson. Another disadvantage is that the non-specific appearance of the with various effects concentrated in one motif and therefore OVD’s overloaded with the range of information for reproductions with color copiers or printing technology Methods for the layperson under the aforementioned conditions is reproduced in an exchangeable manner. Who actually reached Security effect is therefore despite the considerable, for the Production of the OVD's operating expenses, comparatively low.

The invention is therefore based on the object of a visual identifiable, optical and in terms of  Appearance changing security element in such a way shape it easily even by a layperson and in particular quickly and under unfavorable lighting conditions Authenticity can be checked, the use also special instruments or devices for authenticity testing are not should be required. It is also said to be impressive Re-enactment of the OVD's using printing and copying technology be prevented.

A security element is used to solve these tasks of the type mentioned in the invention proposed that the sub-areas of the security element structured in this way are that for a viewer neighboring Sub-areas appear to be clearly contrasting or areas appearing homogeneous contrasting when counterfeited are reproduced, with each sub-area in itself is structured uniformly. In the simplest case it includes the security element only two correspondingly clear distinguishable, in each case uniform sub-areas, so that it would suffice for the user if he took the in optical effects occurring in two areas.

The invention is therefore based on the basic consideration that it for the intended purpose of the simple and rapid identification even under unfavorable Lighting conditions is essential to focus on one comparatively small number of different and clearer limit optical effects, the individual optical Effects in certain areas of the Security element are provided that are sufficiently large are and if possible have a certain shape to get away from that Quickly and easily recognized and distinguished viewers to be able to. The identification is thereby further relieved that clearly in each of the other  contrasting or contrasting in reproduction Sub-areas only provided a uniform structure is. One will proceed appropriately so that at least individual sections are designed such that the in desired optical effect also in these sub-areas unfavorable lighting conditions, e.g. B. diffuse or low light, is still clearly recognizable. So easy recognizable effects are color changes, for example, clearly Defined movements or changes in shape in the area of the the viewer of visible light or clearly visible Switch between structured and high-gloss areas.

In the context of the invention it is possible, for example, that at least a portion of the security element diffractive and / or refractive structure (Diffraction structure), e.g. B. a hologram, interference pattern, Diffraction grating or the like. Has, depending on the type the most different diffraction structure used Effects can be achieved. The can expediently Diffraction structure be designed so that when changing the Illumination or viewing angle a defined, the clearest possible color change is generated. Another Possibility according to the invention is that the Diffraction structure when changing the lighting or Viewing angle motion effects, e.g. B. color changes or Changes in geometric structures. After all it is also possible that the diffraction structure from such Structural elements is composed, for. B. in one Subarea depending on a defined one Viewing angle two or more different geometric figures, for example two different ones Letters or a change between a letter or a number on the one hand and the representation of a head etc. on the other hand.  

Optical effects can be clearly and easily perceived even if the different sub-areas of the Security element a different degree of reflection exhibit.

It is also possible within the scope of the invention that at least a partial area has a matt structure, both chromatic and achromatic matt structures are provided could be.

Another design option for the sub-areas is that that at least one section is not visibly structured is expedient, the at least one partial area is shiny, preferably metallic highly reflective. Straight the contrast between a highly reflective and thus different viewing or lighting angles in substantially identical sub-area on the one hand and its appearance depends on the lighting or Viewing area changing sub-area is a characteristic that the user of the Can easily memorize the value document.

Another possibility for the different design of subareas that are very easy for the viewer identify that is adjacent to each other Subareas have different colors, the different color suitably from a transparent Color varnish is formed, which also serves as a protective varnish, d. H. covers the structure in such a way that scratching or Changing the structure, be it intentional or unintentional, e.g. B. is prevented by use, at least in Partial areas with a diffraction or matt structure is provided.  

The correct identification of the individual sub-areas is then reliably guaranteed if - as according to the invention provided - each section has a minimum diameter or Minimum dimensions in each direction of at least 0.3 mm, preferably of at least 2 mm.

The recognizability or identification of a Security element according to the invention then continues relieved when a first sub-area at least frame-like surrounds a further partial area, advantageously the frame-like first section at least two more, in Partially spaced areas surrounds on all sides. This configuration is conveniently such proceeded that the frame-like, first section was shiny and the further sub-area (s) is a diffraction or Has a matt structure. By the reflective or shiny frame will attract attention of the viewer especially on those within the frame arranged sub-areas directed. Even with reproductions, e.g. B. with color copiers, with such an arrangement a good contrast effect that is clearly perceptible to the viewer created by the more or less chromatic, with low optical density rendering of the Diffractive optical structure areas differ from those in high density values reproducible high gloss Partial stands out clearly.

It is also possible in connection with the invention that at least a portion of a thin film element is formed, whereby thin-film element is to be understood, that in this area a transparent, generally colorless layer is provided, the thickness of which is so small that interference phenomena occur. For this purpose  the layer should definitely be thinner than a quarter of the Wavelength of the light used for viewing.

If, as is also possible according to the invention, at least one Part of the security element is transparent is, there is also a special optical, from Effect easily noticeable to the viewer. It also receives one has the advantage in this case that within the Security element in some areas the surface of the securing value document, for example one corresponding printed paper, shines through, a design that changes very difficult to achieve when trying to counterfeit leaves.

It is also possible for at least one partial area to pass through area-wise removal of a covering several sub-areas Metallization compared to the neighboring one or more Sub-area (s) is designed differently. The way of Demetalization will occur if either transparent sub-areas are sought or a provided over the entire surface of the security element Diffraction structure divided into different sections and for this purpose the diffraction structure in certain areas should be made invisible.

According to the invention, the document of value can be further secured can be achieved if the security element with provide at least one additional security indicator is. As an additional security indicator can be useful an at least partially overarching all sub-areas Pressure or a corresponding embossing may be provided, wherein this pressure usually after application of the Security element to be attached to the value document becomes.  

To form the additional security indicator in the form a special pressure will be advantageous Special colors are used, for example mineral or Metallic effect colors, liquid crystal colors or Coatings, IR and / or UV active colors, daylight Luminous colors or iridescent colors.

Another way to create an additional one Security indicator is a special, difficult forgery of the diffraction structure of at least one To provide part of the security element.

As can be seen from the above explanations, the Security element according to the invention pursues the goal in essentially only a few, for example only two, selected Use effects with high attention value. These effects that are as clear as possible with regard to their optical effect are so in the security elements according to the invention created that at least individual elements also under unfavorable lighting conditions still clearly visible and are effective. The effects themselves are useful in one cognitively favorable external shape, e.g. B. as a concrete symbol or present image from the design of a banknote, being in front all through an interrelation between highly reflective, non-diffractive optics on the one hand and Diffractive optically effective areas on the other hand particularly good results can be achieved. The usage of highly reflective areas also have the advantage that when trying to counterfeit by copy or color printing the highly reflective surfaces black, diffraction optics active structures, however, preferably diffuse and in non-specific colors are reproduced, differences that  even under the unfavorable conditions of payment transactions should be easy to perceive.

In principle, it is possible to use the security element according to the Manufacture invention in different ways and in particular to train on a value document. Regarding it is the handling and attachment on the value document but particularly useful if the invention Security element is part of an embossing or laminating film, which is an adhesive layer for fixing the security element on the document of value or object. Manufacturing process for such embossing or laminating films are generally known and should therefore not be described in more detail here are explained. It is also straightforward for a person skilled in the art clear how B. Hot stamping foils must be constructed if certain optical effects are to be achieved, for example highly reflective surfaces or surfaces with a diffraction structure should be present.

Further features, details and advantages of the invention are more preferred from the following description From examples of valuable documents with Security elements according to the invention with reference to the drawing, each of which shows schematically:

Fig. 1 shows part of a security with a first embodiment of a security element;

Fig. 2 shows a section along line II-II in Fig. 1 and

Fig. 3 shows a part of a security with a second embodiment of a security element according to the invention.

In Fig. 1 is a part of a security document 1, for example, a security such as a banknote, etc., shown on which a total of 2 designated safety element is mounted according to the invention.

In the embodiment of FIG. 1, the visually identifiable, optical security element 2 essentially comprises three sub-areas 2 a, 2 b and 2 c, these sub-areas being dimensioned such that they have minimum dimensions in each direction or a minimum diameter of at least 0.3 mm , but preferably of at least 2 mm. This means that the frame-like portion 2 a has a frame width a of at least 0.3 mm, but expediently of at least 2 mm. The subregions 2 b and 2 c are correspondingly at least 0.3 mm, but preferably at least 2 mm wide and high.

As indicated by the illustration in FIG. 1, the frame-like first partial region 2 a in the exemplary embodiment in FIG. 1 is reflective, for example a high-gloss metallization.

The subregions 2 b and 2 c have different surfaces, each with a diffractive or refractive optical effect. For example, the surface of sub-area 2 b can be formed by a diffraction structure that produces a color change, while the surface of sub-area 2 c can be structured in such a way that when the illumination or viewing angle changes, a color shift, for example in the sense of a beam rotation, such as it has long been known, in particular from decorative films, results.

In the exemplary embodiment in FIG. 1, additional structures 2 d and 2 e in the form of the letters “A” and “X” are arranged within the partial areas 2 b and 2 c, these structures 2 d and 2 e differing in terms of the surface quality of distinguish the rest of sub-areas 2 b and 2 c. For example, as is assumed in the embodiment of FIGS. 1 and 2, the surfaces of the letters "X" and "A" can have a matt structure. The addition of letters or the like is particularly useful if the document of value is a banknote. In this case, the respective short designation of the corresponding currency can be used instead of the letters "A" and "X". B. for Deutsche Mark the letter combination "DM".

As can be clearly seen from FIG. 1, the frame-like partial area 2 a surrounds the partial areas 2 b and 2 c such that there is a small distance 3 between the partial area 2 a and the partial areas 2 b and 2 c. In the same way, the partial areas 2 b and 2 c are separated from one another by a small distance 4 , the security element having no surface structure in the distance areas 3 and 4 . Rather, in the exemplary embodiment shown, it is transparent in the partial areas 3 and 4 , so that the surface 5 of the document of value 1 shines through in the area of the distances 3 and 4 within the security element 2 , a circumstance which helps to improve the security effect of the security element .

The security element 2 of the embodiment of FIGS. 1 and 2 is, as is particularly clear from FIG. 2, part of a hot stamping foil and is applied using a corresponding technique, ie by means of a stamp under the influence of heat and pressure from one in FIG. 2 Transfer the carrier 6 shown in dash-dotted lines to the surface 5 of the value document 1 .

The structure of the security element 2 can also be seen in more detail from FIG. 2.

Starting from the carrier film 6 , this comprises a transparent, deformable protective lacquer layer 7 , a lacquer layer 8 and an adhesive layer 9 for fixing on the surface 5 of the security 1 .

The corresponding diffraction or matt structures are formed at the interface 10 between the transparent, deformable protective lacquer layer 7 and the lacquer layer 8 , these structures being produced by appropriately embossing the protective lacquer layer 7 as long as it is still deformable.

The FIG. 2 clearly shows that, in the portion 2 b diffraction structures 11 are available in the form of substantially parallel lines of a given line frequency and depth. In contrast, in area 2 d of the letter "A", a matt structure 12 is produced, which ensures a diffuse reflection of light. Outside the partial area 2 b, ie in particular in the area of the distances 3 and the glossy frame 2 a, the surface 10 between the lacquer layers 7 and 8 is smooth.

In order to make the diffraction and matt structures clearly visible and to produce the high-gloss surface of the frame 2 a, a metallization 13 is provided between the two lacquer layers 7 and 8 , the metallization where the distance 3 between the frame 2 a and the Sub-areas 2 b and 2 c to be generated is removed.

In Fig. 2 it is finally indicated that the protective lacquer layer 7 can be colored in the section 14 b corresponding to the sub-area 2 b, although the coloring must be such that the protective lacquer layer 7 remains transparent in order to be applied to the document of value 1 Security element 2 can nevertheless recognize the individual subareas 2 a, 2 b and 2 c perfectly. The transparent coloring of the protective lacquer layer 7 in the area 14 offers the possibility of contrasting the two partial areas 2 b and 2 c with respect to one another or with respect to the frame 2 a, but also with respect to the surface 5 of the value document 1 .

The hot stamping film which is used to produce the security element 2 on the document of value 1 according to FIGS. 1 and 2 is produced in a manner known per se. A transparent protective lacquer layer 7 is first applied to a suitable carrier 6 in a customary, preferably printing process, the use of a printing process allowing the application of differently colored areas without difficulty. As long as the protective lacquer 7 has not yet fully hardened or - when using a thermoplastic lacquer for the protective lacquer layer 7 - under the action of heat, the structure 11 , 12 is then introduced in a corresponding replication process. This is followed by z. B. where the non-metallized distance 3 , 4 is to be provided, a soluble, expediently water-soluble lacquer is printed. Now the partially structured surface of the protective lacquer layer 7 pointing away from the carrier 6 is provided with a metallization 13 , for example vacuum-coated with a corresponding aluminum layer. After the application of the metal layer 13 , this is then in the region of the distances 3 and 4 , for. B. removed by washing out the water-soluble lacquer layer and appropriate detachment of the metal layer in these areas. Now the additional lacquer layer 8 and possibly the adhesive layer 9 are applied to complete the hot stamping foil.

In the embodiment of FIG. 3, a value document 1 , for example part of a banknote, is again shown, although here the security element 20 consists of four subareas 20 a, 20 b, 20 c and 20 d that are essentially the same size, each only have different surface structures, which is to be indicated by the different hatching. "Surface structures" is not only to be understood as a spatial configuration as shown in FIG. 2. The “surface structures” of the subareas 20 a to 20 d can also be generated, for example, only by different coloring, by using correspondingly thin lacquer layers, by different reflectivities, etc. In an arrangement according to FIG. 3, however, it is particularly expedient if the subregions 20 a to 20 d, for example, targeted color changes, eg. B. in the sense of a color shift from left to right and opposite from right to left when changing the viewing angle.

In the exemplary embodiment in FIG. 3, an additional security marking is now provided in the form of a pressure 21 that overlaps all sub-areas 20 a to 20 d of the security element 20 , the procedure being expediently such that the pressure 21 is formed by closed and uninterrupted lines, which in turn makes counterfeiting difficult, since continuous printing makes it practically impossible to cut out parts of the document of value and replace them with others.

Furthermore, 21 special colors will usually be used for printing, e.g. B. mineral or metallic effect colors, liquid crystal colors or coatings, IR or UV active colors, daylight fluorescent colors or iridescent colors. If such special colors are used, a further security check can then be carried out by using special light for the lighting, the printing then lighting up or assuming a specific color when the correct wavelength is used for the lighting.

An additional security label cannot only be achieved by overprinting or overprinting. It would also be conceivable, for example, to provide at least one of the partial areas 20 a to 20 d of the security element 20 with a particularly difficult to forge optical structure, the precise configuration of which can also only be identified using special instruments, at least using a magnifying glass.

The application of the security element has been mentioned above according to the invention essentially only for securities explained. Of course it can Security element according to the invention also on others Substrates, especially plastic cards, surfaces of Objects, etc. are attached, which is also in these Cases give the desired benefits.

Claims (23)

1. Visually identifiable, optical security element for documents of value, e.g. As banknotes, official credit cards, passes or check documents, or other objects to be safeguarded, which is adjacent at least two, when illuminated structured differently appearing identifiable with the naked eye portions comprises, characterized in that the partial regions (2 a to 2 e, 20 a to 20 d) of the security element ( 2 , 20 ) are structured in such a way that, for a viewer, each of the adjacent sub-areas appears to be clearly contrasting or, in the case of counterfeiting, homogeneous-looking areas are reproduced in a contrasting manner, each sub-area having a uniform structure. 2. Security element according to claim 1, characterized in that at least a portion ( 2 a to 2 e, 20 a to 20 d) has a light diffractive and / or refractive structure (diffraction structure) ( 11 ), z. B. has a hologram, interference pattern, diffraction grating or the like. 3. Security element according to claim 1 and 2, characterized in that the diffraction structure ( 11 ) generates a defined color change when changing the illumination or viewing angle. 4. Security element according to claim 1 and 2, characterized in that the diffraction structure ( 11 ) when changing the illumination or viewing angle movement effects, for. B. color changes or changes in geometric structures. 5. Security element according to one of the preceding claims, characterized in that the partial areas ( 2 a to 2 e, 20 a to 20 d) of the security element ( 2 , 20 ) have a different degree of reflection. 6. Security element according to one of the preceding claims, characterized in that at least one partial area ( 2 d, 2 e) has a matt structure ( 12 ). 7. Security element according to one of the preceding claims, characterized in that at least one partial area ( 2 a) is not visibly structured. 8. Security element according to claim 7, characterized in that the at least one partial area ( 2 a) appears shiny. 9. Security element according to claim 7 and 8, characterized in that the at least one partial area ( 2 a) is highly reflective metal. 10. Security element according to one of the preceding claims, characterized in that mutually adjacent sub-areas ( 2 a; 2 b, 2 c) have different colors. 11. Security element according to claim 10, characterized in that the different color is formed by a transparent color lacquer ( 7 ) which simultaneously serves as a protective lacquer and at least in partial areas ( 2 b, 2 c) with a diffraction ( 11 ) or matt structure ( 12 ) is provided. 12. Security element according to one of the preceding claims, characterized in that each partial area ( 2 a to 2 e, 20 a to 20 d) has a minimum diameter or minimum dimensions (a) in each direction of at least 0.3 mm, preferably of at least 2 mm. 13. Security element according to one of the preceding claims, characterized in that a first partial area ( 2 a) surrounds at least one further partial area ( 2 b, 2 c) like a frame. 14. The security element according to claim 13, characterized in that the frame-like first portion (2 a) at least two further, spaced at a distance (4) portions (2 b, 2 c) surrounds on all sides. 15. Security element according to claim 13 or 14, characterized in that the frame-like, first partial area ( 2 a) is glossy and the further partial area (s) ( 2 b, 2 c) a diffraction ( 11 ) or matt structure ( 12 ) has (have). 16. Security element according to one of the preceding claims, characterized in that at least one partial area ( 2 a to 2 e, 20 a to 20 d) is formed by a thin-film element. 17. Security element according to one of the preceding claims, characterized in that at least one partial area ( 3 , 4 ) is transparent. 18. Security element according to one of the preceding claims, characterized in that at least one partial area ( 3 , 4 ) by area-wise removal of a plurality of partial areas ( 2 a to 2 e) covering metallization ( 13 ) with respect to the or the adjacent partial area (s) ( 2 a to 2 c) is designed differently. 19. Security element according to one of the preceding claims, characterized in that it is provided with at least one additional security indicator ( 21 ). 20. Security element according to claim 19, characterized in that as an additional security indicator ( 21 ) an all areas ( 20 a to 20 d) at least partially overlapping pressure or a corresponding embossment is provided. 21. Security element according to claim 19 or 20, characterized in that special colors are provided to form the additional security indicator ( 21 ). 22. Security element according to one of claims 19 to 21, characterized in that the additional security indicator is formed by a special, difficult to falsify design of the diffraction structure of at least one partial area ( 20 a to 20 d). 23. Security element according to one of the preceding claims, characterized in that the security element ( 2 , 20 ) is part of an embossing or laminating film ( 6 , 7 , 8 , 9 ) which has an adhesive layer ( 9 ) for fixing the security element ( 2 ) on the document of value ( 1 ) or object.