WO2004097751A2

WO2004097751A2 - Security feature and document comprising said security feature and method for producing and applying said security feature to a document and method for checking authenticity of the document

Info

Publication number: WO2004097751A2
Application number: PCT/DE2004/000820
Authority: WO
Inventors: Hermann Hecker
Original assignee: Bundesdruckerei Gmbh
Priority date: 2003-04-25
Filing date: 2004-04-20
Publication date: 2004-11-11
Also published as: EP1618007B1; WO2004097751A3; DE10318715A1; DE502004002962D1; ATE354479T1; EP1618007A2

Abstract

The invention relates to a security feature comprising an information structure (27, 45, 97, 107), disposed along a lateral extension (25, 49, 65, 83, 99, 109) of the feature (21, 41, 91, 101), and an optically effective reproduction structure (29, 43, 50, 60, 70, 80a, 80b, 95, 105) by means of which information (94, 115) of the information structure (27, 45, 97, 107) can be read out subject to a predetermined condition. The inventive security feature (21, 41, 91, 101) is also characterized in that the reproduction structure (29, 43, 50, 60, 70, 80a, 80b, 95, 105) is configured by a plurality of optical wave guide elements (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111), one optical wave guide element (37, 46, 51 a, 51 b, 51 c, 61, 71, 81a, 81b, 96, 111) extending between an end facing the information structure (27, 45, 97, 107) and an end facing away from the information structure (27, 45, 97, 107) and forms along its extension a finite angle (ε) with respect to the lateral extension (25, 49, 65, 83, 99, 109) to define the predetermined condition. The invention also relates to a document (20, 40, 90, 100) which comprises such a security feature (21, 41, 91, 101), to a method for producing the security feature and to a corresponding document, as well as to a method for checking authenticity of the document.

Description

Security feature and corresponding document, method for producing the security feature and method for checking the authenticity

The invention relates to a security feature comprising an information structure arranged along a lateral extent of the feature and an optically effective imaging structure, by means of which information of the information structure can be read out depending on a predetermined condition. The invention also relates to a document with the security feature. The invention further relates to a method for producing the security feature, a carrier being provided and an information structure which is suitable for receiving information being applied along a lateral extent to the carrier and an optically effective imaging structure being applied to the information structure by means of which information of the information structure can be read out depending on a predetermined condition. Such a security feature is attached to a document in a suitable manner. Furthermore, the invention relates to a method for checking the authenticity of the document.

A security feature can be implemented in a particularly simple manner by means of a so-called “tilt image”, which is also known under the abbreviations “MLI” or “CLI” for “laser image” (English). Such a tilt image generally has a lens structure along its lateral extent as an optically effective imaging structure and is realized with an information structure stored in the lens structure. In different viewing directions, depending on the design of the tilt image, an image is visible or not visible or only to a very limited extent. Such tilting pictures are for example as a security feature on plastic cards and identification papers attached. Flip pictures can also be found on postcards. The advantage lies in the fact that the tilting pictures can be checked visually in a relatively simple manner, which is given even under simple lighting conditions. Such a tilt picture is disclosed for example in EP 0 219 012 A2.

As disclosed in EP 0 216 947 A1, additional relief lenses can be provided to increase the security against forgery.

Tilt pictures of the type mentioned can be realized using different materials, for example as disclosed in DE 100 07 916 A1. The change of motif described above when tilting the document on which the tilt image is located is therefore generally realized using microlenses. Other forms of implementation can be holograms or thin, multi-reflecting layers for iridescent effects. In any case, these are diffractive structures, which are composed of one or more layers in a lateral extent. The lateral optically effective and diffractive boundary layers serve to map the information stored in the information structure and, at the same time, to generate a variability when viewing or reading out the stored information. In this way the change of motif comes about. Such light diffractive, refractive or simply reflecting boundary layers are all arranged parallel to the lateral extent of the security feature.

This also applies to the gratings or diffraction structures of WO 02/11063 A2, in which the effect can also be non-visual and the reading and reading of the information is laser-assisted, possibly in the non-visible area of the light. Such an invisible and inconspicuously hidden security feature is known for example from DE 3 233 197 A1.

The simple nature of such tilting images, which are realized by means of optically active boundary layers arranged parallel to the lateral extent, also has the disadvantage that they are relatively easy to forge. For example, the lens structures of the type mentioned above are relatively inexpensive and easy to obtain. A lens or diffraction structure of the type mentioned above has a certain surface roughness which can wear out and lead to a change in the appearance of the security feature, which in the worst case can lead to dilution or a deterioration in the detectability of the security feature. Tilting pictures of the type mentioned above can therefore be easily damaged and reproduced, because the security deposit is generally only in the stored motif in combination with the tilting effect, even if a relief according to EP 0 216 947 A1 is additionally provided or the security feature itself DE 3 233 197 A1 is hidden.

It would therefore be desirable to provide a security feature that has increased security, ie a security feature that has improved security against forgery. This is where the invention comes in, the task of which is to specify a security feature and a document with such a security feature that permits increased security, which is brought about in particular by increased robustness and variability. Likewise, such a task arises in a method for producing the security feature and in a method for attaching the security feature to the document. The object of the present invention is also to specify a method for checking the authenticity of the document.

With regard to the security feature, the object is achieved by the invention by means of a security feature of the type mentioned at the outset, in which the imaging structure is formed by means of a number of light guide elements, wherein a light guide element extends between one end facing the information structure and one end facing away from the information structure and for specification the predetermined condition along its extension forms a final angle to the lateral extent.

The invention is based on the consideration that the optically active boundary layers previously used in tilted images are disadvantageously arranged parallel to the lateral extent of a security feature, that is to say perpendicular to an optical axis of the imaging structure layer, and are therefore limited in their security performance. In terms of robustness, they are easy to damage. With regard to variability, they only have one degree of freedom due to their geometric alignment.

The invention is based on the knowledge that a security feature can also be implemented with optically effective boundary layers that have an orientation that differs significantly from the lateral extent of the security feature. It has been found that light guide elements are surprisingly suitable for forming an imaging structure for a security feature. The invention takes into account the consideration that an imaging structure can be formed by means of a sufficient number of light guide elements. The optically active boundary layers of the light guide elements act light-guiding, that is, for. B. by means of total reflection or multiple reflection, to achieve the optically variable effect, which makes a significant difference to the only light-refractive optically active boundary layers in previously known tilt images. Since a light guide element essentially only allows light to pass in the direction of one allowed optical axis of a light guide element, or only in a limited conical angular space around this direction, surprisingly novel optically variable effects can be achieved. The interaction of the number of light guide elements can achieve a security-enhancing optical effect that is improved in terms of robustness and variability, the security performance of which can lie not only in the information stored in the information structure, but also in the mapping structure itself.

The invention also takes into account the consideration that the predetermined condition, depending on which information of the information structure can be read out, can be varied in a particularly varied manner in the proposed security feature. The method for checking the authenticity of the present invention described below is thus considerably safer than other known methods. The predetermined condition could be realized, for example, in the form of irradiation and / or viewing the security feature from a defined direction. The optically variable effect could be realized, for example, in the form of a contrast and / or a difference in brightness. The predetermined condition and the optical variable effect preferably work together in such a way that during an authenticity check, e.g. B. when viewing the information structure, an effect of the change in contrast and / or change in brightness depending on the viewing angle can be seen. This preferably results in the appearance or disappearance of a motif contained in the information structure. An optical waveguide element of the proposed security feature extends between an end facing the information structure and an end facing away from the information structure and in doing so forms a finite angle to the lateral extent along its extension for specifying the predetermined condition. The manner in which such a light guide element extends between its ends and which angle it forms in relation to the lateral extension provides a degree of freedom which can be used particularly expediently to provide an increased security performance of the security feature. For this purpose, depending on the application, the arrangement of the light guide elements to each other, the alignment of the light guide elements to each other and overall, as well as the configuration of the light guide elements themselves, for. B. in terms of material and type, are used in detail. The security feature proposed here therefore offers a considerably increased variability, which can be used with regard to the security performance. Light guide elements also prove to be due to their non-parallel arrangement for the lateral expansion of the security feature, as much more robust compared to the commonly used, laterally oriented, light-diffractive boundary layers.

In the proposed concept, an optically effective boundary layer is understood to mean any type of boundary layer which is optically effective for electromagnetic waves in the range between the extreme ultraviolet and far infrared. Accordingly, a light guide element in any form, e.g. B. as a light-conducting optical fiber, such as from a suitable glass or polycarbonate, or z. B. also as a suitable waveguide of any kind, for. B. made of metal or as an internally coated micro-holes in a solid material. In principle, a light guide element is to be understood as any type of arrangement of light-conducting boundary layers.

Advantageous developments of the invention can be found in the subclaims and specify advantageous options in particular for realizing the variability or robustness of the proposed security feature.

In principle, a light guide element could be curved as desired and each light guide element of the number could be arranged, aligned and designed differently. However, it proves to be particularly expedient that the light guide element forms a fixed angle to the lateral extent along its extension, i. H. runs straight. In particular, the number of light guide elements is aligned parallel to one another with a fixed angle to the lateral extent. In this way, z. B. reproduce a motif as resolvable information particularly well.

A fixed angle of 90 ° is particularly preferred. The angle is preferably between 30 ° and 90 °. Depending on the application, any angle in between could be selected, e.g. B. an angle of 60 °. The information of the information structure can be read particularly well in the direction of the angle. That means, depending on the choice of the angle, in the case of vertically arranged light guide elements, due to their vertically arranged optically light guiding boundary layers, the high reading quality is achieved with a reading direction perpendicular to the lateral extension. In the case of diagonally arranged light guide elements, the particularly good reading quality of the information is shifted to one Direction according to the selected finite angle, which the light guide elements or their optically active boundary layers form for lateral expansion.

It proves to be particularly advantageous if the number of light guide elements is formed by a light guide bundle. In particular, the light guide elements are arranged directly adjacent to one another for this purpose.

The number of light guide elements could be isolated or embedded in the filler material as a light guide bundle. This could be a filler material formed by the document material. It is particularly expedient if the filler material increases the reflective properties of the boundary layer of a light guide element.

With regard to the preferred extension of a security feature, it proves to be particularly expedient if the light guide element has a length that is between 50 μm and 1000 μm. A diameter between 5 μm and 50 μm has proven to be particularly advantageous.

According to a particularly preferred development of the invention, the security performance of the security feature can be increased considerably by arranging the number of light guide elements in the lateral extent of the feature relative to one another in accordance with a regular characteristic. For example, a two-dimensionally orthogonal or hexagonal geometry could be selected, or a fixed, but arbitrary looking arrangement.

In particular, two variants of the particularly preferred further development prove to be expedient. According to a first variant, the characteristic of the mapping structure could be superimposed on the information read out from the information structure. In this way, a read motif in its read appearance, in addition to the motif itself, could have optical effects superimposed by the characteristic, for example caused by differences in brightness or contrast.

According to a second variant, the characteristic of the mapping structure could be superimposed on the information of the information structure itself. This can expediently be achieved in that when the security feature is produced, the information passes through the mapping structure into the information structure. When introduced, the optical effects caused by the characteristic would be transferred to the information structure.

Both of the above-mentioned variants provide a security feature in which an additional security deposit is invisibly and inconspicuously hidden, namely predetermined by the characteristic. There are many possibilities by arranging the light guide elements in relation to one another and by different possibilities for inserting and reading out the information. For example, the type and wavelength of different light sources or lasers could be used to provide increased security.

For a production of the security feature, it is particularly expedient to accommodate the information structure in a first layer and the optically effective imaging structure in a second layer along the lateral extent. In this way, the two structures could be arranged one above the other in a particularly simple manner as a layer sequence. It goes without saying that this is not a necessary requirement. In principle, both structures could merge into one another and be delimited as desired.

In addition, it proves expedient to provide additional optical imaging elements with a lens and / or diaphragm effect in order to improve the imaging properties. Above all, an aperture surrounding the information in the first layer proves to be advantageous as an additional optical imaging element. In this way, advantageous shading can be provided, in particular for visually perceptible motifs, which, above all, make it difficult or impossible for the light to be incident on the side of the motif in order to support the visually perceived changes in contrast or brightness.

The invention also leads to a document with a security feature of the type mentioned above. This could be a plastic card or an identity document of any kind, e.g. B. an ID or ID card, a driver's license or all types of cards, especially from cashless payments such as credit cards or cash cards. In the following, a document is used to describe any type of security-enhanced document or object, regardless of its form, material, rial or use. As information, light-emitting, e.g. B. fluorescent substances, motifs, such as hard-to-copy print patterns, personalized information such as images, logos and the like, or characters, letters, numbers and chains of numbers can be incorporated into the information structure.

The security feature could preferably be located on the surface of the document. According to a preferred embodiment, it proves to be particularly favorable if the security feature is accommodated inside the document. It is particularly expedient if the document has an optically transparent area at least in the area of a lateral extension of the security feature. For example, the security feature could be read from the top of the document, while the security feature is appropriately irradiated from the bottom of the document. The readout and radiation wavelengths do not necessarily have to match. The optically transparent area is advantageously translucent in the visual wavelength range.

The object with regard to the method is achieved according to the present invention by a production method of the type mentioned at the outset, in which the imaging structure is formed in the form of a number of light guide elements according to the invention, the number of light guide elements from one light guide bundle under one being used to specify the predetermined condition finite cut-off angle to the axis of the light guide bundle is cut off, and the imaging structure is applied to the information structure, wherein a light guide element extends between an end facing the information structure and one end facing away from the information structure, and along its extension forms a finite angle to the lateral extent defined by the cut-off angle ,

The invention is based on the consideration that an imaging structure with light guide elements can be expediently cut from a light guide bundle or sawed off or otherwise removed or removed, and in this way a particularly favorable production of the security feature can take place. The above-mentioned characteristics of a mapping structure can also be easily implemented. For example, optical fibers could already be geometrically arranged in a fiber bundle in a characteristic manner. According to a particularly preferred embodiment of the production method, the number of light guide elements in the lateral extent of the feature is arranged relative to one another in accordance with a regular characteristic and the information is introduced through the optically effective imaging structure layer into the information structure layer, so that thereafter the characteristic of the imaging structure is superimposed on the information of the information structure itself.

A security feature described above can be attached to a document in any manner. H. apply to the surface of a document or completely or partially accommodate inside a document. According to the invention, it proves particularly expedient to manufacture the security feature as such by the manufacturing method described above and then to attach it to the document. However, a carrier could also be provided on a document and the security feature could be produced on the document using the manufacturing method described above.

Furthermore, the object is achieved according to the invention by a method for checking the authenticity of a document of the above-mentioned type with a security feature of the above-mentioned type, in which an optically variable effect is achieved depending on the predetermined condition, so that in the direction of the finite angle the Information is read out in a certain quality and with increasing deviation from the finite angle, the information is read out with changed quality. With this type of security feature, the angle with good readout quality is therefore predetermined by the finite angle which the optically active boundary layer of the light guide element forms with the lateral extent of the security feature. The optically active boundary layers of the light guide elements are aligned non-parallel to the lateral extension.

In the authenticity check, with increasing deviation from the finite angle, the optically variable effect is advantageously brought about in such a way that the information of decreasing quality, e.g. B. in terms of contrast and / or brightness, is read out. In principle, the predetermined condition could be any expedient condition when reading out the security feature, as determined by the finite angle or by the light guide elements themselves. It proves to be particularly expedient that the predetermined condition is implemented in the form of irradiation and / or viewing the document from a direction defined by an angled finite angle.

The optically variable effect can also be chosen as desired, depending on the type of application. It has proven particularly expedient for the optically variable effect to be realized in the form of a contrast and / or difference in brightness.

An embodiment of the invention is explained in more detail below with reference to a drawing. In comparison, the prior art is also shown. The drawing is not necessarily to show the exemplary embodiments to scale, rather the drawing, where useful for explanation, is carried out in a schematic and / or slightly distorted form. With regard to additions to the teachings which can be seen directly from the drawing, reference is made to the relevant prior art. It should be taken into account here that various modifications and changes regarding the form and detail of an embodiment can be made without departing from the general idea of the invention.

Preferred embodiments of the invention are described in connection with a motif applied to a plastic card. In particular, a visual readout of the motif is provided. In addition, however, any different and modified embodiment of the invention can be used without departing from the general idea of the invention. The features of the invention disclosed in the above description, in the drawing and in the claims can be essential for the embodiment of the invention both individually and in any combination. The general idea of the invention is not limited to the exact form or the detail of the preferred embodiments shown and described below, nor is it restricted to an object which would be restricted compared to the object claimed in the claims.

In detail, the drawing has the following figures: Figure 1 shows the principle of image formation in a tilt image according to the prior art;

FIG. 2 shows the principle of the embodiments according to the present invention, in which the imaging structure is formed by means of a number of light guide elements;

FIGS. 3a, 3b, 3c show the effect of an optically active boundary layer in the embodiments of the present invention, the boundary layers being arranged at a finite angle to the lateral extent of the security feature in order to specify the predetermined condition;

FIG. 4 shows a document with a security feature according to a first preferred embodiment of the invention;

FIG. 5 shows a spaced arrangement of light guide elements which can be implemented in the embodiments of the present invention;

FIG. 6 shows an arrangement of the light guide elements which deviates from a right angle and which can be implemented in the embodiments of the present invention;

FIG. 7 shows a particularly preferred ratio of a length to a diameter of a light guide element, which can be realized in the embodiments according to the invention;

FIGS. 8a, 8b show advantageous characteristics as a geometric arrangement of light guide elements in an imaging structure along the lateral extent of a security feature, which can be implemented in the embodiments of the present invention;

FIG. 9 shows a document with a printed motif and a security feature according to a second preferred embodiment of the present invention; FIG. 10 shows a document with an information structure, comprising information introduced by laser, an additional screen and a security feature in accordance with a third preferred embodiment of the invention.

FIG. 1 shows a data carrier 1 of the prior art, in which the principle of image formation in a tilted image is used as a security feature. In this tilt image 3, an information structure layer 7 of an optically effective imaging structure layer 9, which is arranged along a lateral extent 5 of the security feature 3, is deposited. Both layers 7 and 9 are located on a corresponding carrier 11 of the data carrier 1. The optically active boundary layers 13 of the optically active imaging structure layer 9 are indicated here as diffraction structures. The optically active boundary layers 13 run parallel to the lateral extent 5 of the optically effective imaging structure 9 and thus also parallel to the lateral extent 5 of the identification card 1 itself. The same applies to tilt images, the optically active imaging structure layer 9 of which is formed by means of microlenses or other optically active boundary layers , The situations 1a and 1b shown by way of example in FIG. 1 each show a predefined irradiation direction 15a and 15b of an illumination and a direction 17a and 17b which essentially coincides with the irradiation direction. An image can only be recognized in these directions 17a and 17b, caused by the optically effective boundary layers 13 of the optically active imaging structure 9. The image can be recognized best when the viewing direction coincides with the direction of irradiation 15a and 15b. The image is also still recognizable within the strip-shaped angular space described by the directions 17a and 17b, which is predetermined by the radiation directions 15a and 15b. Outside such a strip-like angular space, the motif stored in the imaging structure cannot be recognized at all in the information structure 7, or can only be recognized very poorly. Different information is usually stored in both directions, so that when the carrier is rotated from one angular area to the next, the viewer receives the impression of a tilting of the image from one item of information to another (“tilting image”).

The “tilt image” principle as such is used for an improved security feature in accordance with the embodiments of the invention presented below, but is implemented completely differently than in the prior art. This results in a completely different effect and significant improvements with regard to an information structure. door layer 7 and in particular relating to an imaging structure layer 9. As an essential principle, the fact that optically effective boundary layers according to the embodiments of the invention are no longer arranged parallel to the lateral extension 5 of the data carrier 1, but in a direction substantially different from the lateral extension, So above all perpendicular to the lateral extent 5 and obliquely to it.

The principle of the embodiments according to the invention is explained in FIG. 2.

FIG. 2 shows, again in schematic form, a data carrier 20 of a first preferred embodiment of the invention, in which the security feature 21 is attached to a carrier 23 of the data carrier along a lateral extent 25 thereof. The security feature has an information structure 27 and an optically effective imaging structure 29, both in the form of lateral layers, but the optically active boundary layers 31 are not arranged parallel to the lateral extent 25 in the embodiments of the invention and are along in the embodiment of FIG. 2 a direction 33 perpendicular to the lateral extent 25. The optically active boundary layers 31 are formed by light guide elements, which are likewise arranged along the vertical direction 33. This has the completely new effect that a motif stored in the information structure 27 can best be recognized only from a single direction 33, which runs perpendicular to the lateral extension 25 and thus in the direction of the optically active boundary layers 31. Likewise, the motif of the information structure 27 can also be recognized within a cone 35 about this direction 33, but the quality of the readability decreases with increasing deviation from the direction 33. Outside the cone 35, the motif of the information structure layer 27 can only be recognized very poorly or not at all.

FIGS. 3a, 3b and 3c explain the principle of operation of the light guide elements used in the embodiments of the invention. Such a light guide element 37 within the imaging structure 29 is shown schematically in FIGS. 3a, 3b and 3c. Likewise, the direction 33 perpendicular to a lateral extension 25 is indicated in dashed lines. The alignment of the light guide element 37 with respect to the lateral extension takes place here at a finite angle ε that is 90 °. As will be shown with reference to the further FIG. 6, a different angle ε (FIG. 6) between the alignment direction 33 of the light guide element 37 and the lateral extension 25 could also be selected. To explain the principle of operation of the embodiments of the invention, an angle of 90 ° is chosen for the sake of simplicity. It is also clear that this finite angle can be defined via two solid angles α and β, which further determine the direction 33 relative to the lateral extension 25. Both solid angles .alpha. And .beta. Can be varied as desired in accordance with further embodiments of the invention and thus lead to a wide range of possible uses of the proposed concept.

As shown in FIG. 3a, light 39a incident parallel to the direction 33 of the light guide element 37 formed here as a fiber is not reflected or deflected. In this case, information of the information structure 27 stored in the mapping structure 29 can best be read out. If the angle Y of the incident light 39b deviates from the direction 33 of the light guide element 37, as shown in FIG. 3b, there is first total reflection 36 at the boundary layer 31 of the light guide element 37. FIG. 3c shows that with larger deviations δ from the direction 33, the incident light 39c escapes from the light guide element by refraction 38 at the boundary layer 31 of the light guide element 37. Thus, in the case of FIG. 3c, information from the information structure 27 below the mapping structure 29 would be impossible or difficult to read out. That is, at a certain angle between 0 ° of FIG. 3a and the angle δ of FIG. 3c, for example at the angle Y of FIG. 3b, the cone 35 of FIG. 2 should be described, within which the information of the information structure 27 can just be read , d. that is, at the angle Y there is just total reflection.

The same principle applies in reverse for light that is emitted by the card 20, for example in the event that the security feature 21 of the card 20 would be irradiated from behind. As a security feature, in the preferred embodiments according to the invention, the effect of a change in brightness or contrast that is visible or otherwise measurable for the user, that is to say an optically variable effect as a function of a predetermined condition, in this case the viewing angle or, in the case of a directional light source to illuminate the data carrier 20 from behind, from the illumination angle. In addition to a change in contrast or brightness, the optically variable effect could also lie in another change in the appearance of the stored information of the information structure 27. The predetermined condition could be realized not only in the form of irradiation and / or viewing of the data carrier 20 or the lighting of the data carrier 20, but also in another form. Another form would be, for example, the use of different wavelengths when irradiated with a laser. In this case, the properties of a total reflection 36 and the properties of a refraction 38 would change with a light guide element 33 used. Therefore, the optically variable effect would change depending on the predetermined condition. It could e.g. B. different information at different wavelengths used. Here, too, there is a wide range of possible variations with regard to the implementation of the security feature 21 in the embodiments of the present invention.

Further implementation options relate to the light guide element 37 itself. Here, light guide elements 37 could be implemented as optical fibers, for example. Both optically visible wavelengths and optically invisible wavelengths in the infrared or ultraviolet range can be used. An optical fiber usually consists of a jacket and a core. The core has a refractive index ni that is greater than the refractive index n _{2 of} the surrounding cladding. This is a condition for total reflection in the optical fiber. This means that the cladding with the refractive index n ₂ is made of an optically thinner medium than the core with the refractive index ni. The limit angle Y, at which total reflection is just still taking place at a boundary layer 31 of a light guide element 37, can be approximated using the formula

sinö = V (",) ² - (" ₂ ) ²

describe. However, this formula only applies if the boundary medium to the optical fiber 37 has a refractive index n ₀ = 1, that is, for. B. with air as the boundary medium, which is usually not the case in the present embodiments. The formula is intended to illustrate the principle of total reflection. In the embodiments of the invention, the boundary medium consists either of document material or, optionally, of a suitable filler material, by means of which the total reflection properties of a light guide element 37 and the refractive properties The properties of a light guide element 37 at the boundary layer 31 can be changed such that, for example, the angle Y, at which total reflection 36 is just possible at the boundary layer 31, expediently becomes particularly large. Various types of optical fibers can also be used. For example, only optical fibers in their design as steps or gradient fibers are mentioned here. Multimode fibers would normally be used. However, there is no reason not to use single-mode fibers. A fiber usually has a circular cross section. Any other form of optical fiber would also be conceivable. In particular, reference is made to the wide range of usable plastic optical waveguides, which are described in detail in the book by Andreas Weinert, "Plastic Optical Waveguide, Basic Components, Installation" by the Publicis MCD Verlag from 1998, ISBN No. 3- 89578-059-6 which is hereby incorporated by reference into the disclosure of the present application, typically an optical fiber for use in the embodiments of the present invention would be made from materials such as polycarbonate, PMMA (plexiglass) or glass.

For very long-wave electromagnetic waves in the μm range, in addition to the plastic waveguides described, metallic waveguides would in principle also be possible for realizing the concept of a security feature proposed here.

The individual dimensions of the dimensions which a light guide element should have in the embodiments of the present invention are also explained with reference to FIG.

FIG. 4 schematically shows a further preferred embodiment of a data carrier 40 which has a security feature 41. The security feature 41 has an imaging structure 43 in the form of a layer and an information structure 45 in the form of a layer and a carrier 47. In this case, the information structure layer is simply formed by the boundary layer between imaging structure layer 43 and carrier 47. This example is intended to clarify that special information does not necessarily have to be stored in the information structure 45. The security deposit could be provided solely by the mapping structure 43, for example by attaching certain characteristics in the mapping structure 43, which can be achieved, for example, by means of an arrangement, direction or further design of the mapping structure. This will be explained in detail in particular with reference to FIGS. 8a and 8b. Other possible variations with regard to the imaging structure have already been explained with reference to FIGS. 2 and 3a to 3c. In the present preferred embodiment, the imaging structure layer is arranged along a lateral extent 49 on the data carrier 40. The light guide elements 46 are aligned with their boundary layers 48 perpendicular to the lateral extension 49. Furthermore, they are essentially closely adjacent or abutting one another and arranged parallel to one another. In principle, the close parallel arrangement of all light guide elements 46 is suitable for clearly recognizing the information of the information structure 45. In principle, however, an isolated and non-parallel arrangement of light guide elements could also be provided. Likewise, individual groups of closely adjacent and parallel to each other light guide elements could be provided, so that only isolated points or sections of the information structure 45 are visible or readable under a predetermined condition. With the arrangement of the light guide elements 46 according to the embodiment in FIG. 4, a situation is predefined which essentially corresponds to the situation described in FIG.

FIG. 5 shows an optically effective imaging structure 50 formed as a layer with light guide elements 51a, 51b and 51c. The light guide elements 51a and 51b touch as little as the light guide elements 51b and 51c. In this embodiment there is a filler material in the spaces 53, 55, which improves the total reflection and refraction properties of the light guide elements 51a, 51b and 51c in accordance with the principle explained with reference to FIGS. 3a to 3c in such a way that the angle Y at which just total reflection is still present 36 at an interface 31 is possible, is optimized, in this case, is as large as possible.

FIG. 6 shows a further preferred embodiment of an optically effective imaging structure 60, in which the light guide elements 61 with their boundary layers 63 are arranged obliquely, ie at a non-perpendicular angle to the lateral extension 65 of the imaging structure layer. As already explained with reference to FIGS. 3a, 3b and 3c, the oblique alignment can be defined by corresponding solid angles α, β, which in the embodiment of FIG. 6 no longer amount to 90 °. Accordingly, in this embodiment, according to the predetermined condition selected here, according to Angle α, β is the optically variable effect, ie a maximum brightness or contrast in direction 67. That is, in the case of obliquely arranged light guide elements 61 with their boundary layers 63, stored information of the information structure would no longer be possible with a vertical viewing angle of the data carrier, but would come , corresponding to the tilt angle ε of the light guide elements 61 with their boundary layers 63 to the lateral extension 65, is shifted in the direction 67 and within a cone 69 determined by the angle Y of the total reflection.

FIG. 7 shows the dimensions of an imaging structure layer 70 and an optical fiber arranged therein as an optical fiber element 71. The optical fiber has a length "I" and a diameter "d". The ratio of the length I of the fiber to the diameter d of the fiber should be at least five. However, this does not rule out that smaller ratios can also be appropriate if the application requires it. A diameter d of the fiber between 5 μm and 500 μm typically proves to be advantageous. A length could be between 50 μm and 1000 μm. The imaging structure 70 preferably has a layer thickness of 100 μm, so that the length I of the fiber also lies in this range. An imaging structure layer could additionally have a protective layer 73. The protective layer 73 could in principle also be dispensed with, since an optical fiber, unlike previously known lateral optically active structures, is very robust against signs of wear and tear. B. hardly scratched during normal use.

FIGS. 8a and 8b show different possible arrangements of light guide elements 81a and 81b designed as optical fibers, each in an imaging structure layer 80a and 80b in a lateral extent 83. The arrangement 85a in FIG. 8a corresponds to an orthogonal two-dimensional geometric arrangement. The arrangement 85b in FIG. 8b corresponds to a two-dimensional hexagonal geometric arrangement. Any other regular geometric, even non-pattern, arrangement is equally conceivable. In any case, the imaging structure 80a, 80b would be imprinted with the regular characteristic caused by the arrangement of the light guide elements 81a, 81b. With a corresponding design of the security feature, this naturally has an effect on a piece of information that is read out, which is read out by the light guide elements 81a, 81b. Specifically, this means that e.g. B. when viewing a stored motif, the geometric arrangement of light guide elements 81a as a regular characteristic of the fiber-optic layer 80a, 80b is also imaged. In this way, a further characteristic security performance of the security feature according to the embodiments of FIGS. 8a and 8b is made available. Such security deposit may only be possible with aids such. B. recognizable with a magnifying glass and thus not recognizable for untrained people. This means that the orthogonal arrangement 85a of FIG. 8a or the hexagonal arrangement 85b of FIG. 8b of the light guide elements 81a and 81b is an equally concealed and inconspicuous security performance of the respective security feature.

In the embodiments of FIGS. 8a and 8b, it is also appropriate to transmit the information of the information structure by laser engraving. In this case, the regular characteristic 85a, 85b would be superimposed on the information of the information structure, for example a motif. In this case, the information structure is technically designed so that it is able, for. B. by recording brightness and / or contrast features to record the regular characteristic 85a, 85b due to the laser effect in addition to information already available. This has the advantage that the information of the information structure and the mapping structure with their regular characteristics are inseparable from a security point of view and in any case cannot be produced separately and therefore cannot be falsified. The embodiments of the security feature in FIGS. 8a and 8b thus provide a security feature that is particularly secure against forgery.

FIG. 9 shows a further embodiment of a data carrier 90 with a security feature 91 and a carrier 93, which is essentially the document on which the security feature 91 is located. The security feature 91 has an imaging structure 95 in the form of a layer and an information structure 97 in the form of a layer. All layers are equally arranged along a lateral extent 99. The light guide elements 96 are arranged with their boundary layers 98 perpendicular to the lateral extension 99. In the embodiment shown here, the information 94 is implemented as a printed motif. Such a motif can be, for example, a photo or other personalized information. Motifs are particularly useful for documents such as check cards, driver's licenses or ID cards. A further embodiment of a data carrier 100 with a security feature 101 and a carrier 103 is shown schematically in FIG. The security feature 101 has an imaging structure 105 in the form of a layer and an information structure 107 in the form of a layer. Again, all layers are aligned parallel to the lateral extent 109 of the data carrier 100. The imaging structure 105 has a plurality of light guide elements 111 with their boundary layers 113. In the embodiment in FIG. 10, a lateral incidence of light on the information 115 of the information structure 107 is made more difficult or prevented by additional measures. In this way, visually perceived changes in contrast or brightness are supported. In particular, in this embodiment, a motif or a name or other personalized information 115 is partitioned off by an aperture 117 surrounding the information on the side. Such measures are particularly appropriate when the information 115 is introduced into the information structure layer 107 by laser engraving via the optically effective imaging structure layer 105. The screen 117, which acts as a screen, can also be laser-engraved into an information structure layer 107 in the form of a laser-active layer.

FIGS. 9 and 10 also show that when a security feature is produced in accordance with one of the previously explained embodiments, the information can be introduced into the information structure both before and after a composition of the security feature, from the information structure and the mapping structure. In FIG. 9, the information 94 is already present in the information structure 97 when the information structure layer 97 and the imaging structure layer 95 are combined to form the security feature 91. In contrast, in the embodiment of FIG. 10, a “bare” information structure layer 107 is brought together with an imaging structure layer 105. The information 115 is only introduced when the security feature has already been produced or is even on a document or on a carrier 103 of a data carrier 100.

In all the embodiments described above, it proves to be particularly advantageous if the light guide elements used in the imaging structure layer are removed from a light guide bundle; for example, they could be sawn off or cut off as a layer. It is irrelevant whether the light guide elements are directly adjacent, for example as in FIG. for example in FIG. 5 spaced apart from each other are embedded in filler material. It is equally advantageous to produce bundles with or without filling material. Bundles can also be produced in which a characteristic according to the embodiments of FIGS. 8a or 8b already exists. In each of the cases explained, a layer of appropriate thickness, as explained, for example, with reference to FIG. 7, can be removed at a perpendicular cutting angle to the elongated axis of the light guide bundle. In this way, an imaging structure layer is obtained directly. This is then applied to an information structure layer in such a way that a light guide element extends between an end facing the information structure layer and an end facing away from the information structure layer. In the embodiment of the production method mentioned here, a perpendicular cutting angle corresponds to a right finite angle of the extension of a light guide element for the lateral expansion of the imaging structure layer, that is to say, for example, an embodiment of FIGS. 2, 4, 9 or 10.

In the event that the layer with light guide elements is removed from a light guide bundle at a different finite intersection angle to the axis of the light guide bundle, the intersection angle, for example as shown with reference to FIG. 6, would be practically the finite angle ε that a light guide element with the late rale expansion of an imaging structure layer forms.

In summary, the present invention relates to a security feature 21, 41, 91, 101, which has increased security compared to a so-called tilt image. For this purpose, the security feature 21, 41, 91, 101 has an information structure 27, 45, 97, 107 arranged along a lateral extent 25, 49, 65, 83, 99, 109 of the feature 21, 41, 91, 101 and an optical one effective mapping structure 29, 43, 50, 60, 70, 80a, 80b, 95, 105, by means of which information 94, 115 of the information structure 27, 45, 97, 107 can be read out depending on a predetermined condition. In the case of the proposed security feature 21, 41, 91, 101, the imaging structure 29, 43, 50, 60, 70, 80a, 80b, 95, 105 is also by means of a number of light guide elements 37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111 is formed, with a light guide element 37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111 between one facing the information structure 27, 45, 97, 107 and one Extends the end facing away from the information structure 27, 45, 97, 107 and forms a finite angle ε to the lateral extent 25, 49, 65, 83, 99, 109 along its extension for specifying the predetermined condition. Correspondingly, a document 20, 40, 90, 100 with such a security feature 21, 41, 91, 101 is provided. In an intended production method, the number of light guide elements 37, 46, 51a, 51b, 51c, 61, 96, 111 is separated from a light guide bundle at a finite cut-off angle to the axis of the light guide bundle, and the finite angle is above the cut-off angle ε defined for the lateral extent 25, 49, 65, 83, 99, 109. The security feature 21, 41, 91, 101 can either be produced as a whole and then attached to a document 20, 40, 90, 100 or else be produced on the document 20, 40, 90, 100. When checking the authenticity of such a document, an optically variable effect is achieved depending on the predetermined condition, so that in the direction of the finite angle ε the information 94, 115 is read out in a predetermined quality and with increasing deviation from the finite angle ε the information 94, 1 5 can be read with changed quality.

Claims

claims

1. Security feature (21, 41, 91, 101), comprising an information structure (27, 45,) arranged along a lateral extent (25, 49, 65, 83, 99, 109) of the feature (21, 41, 91, 101) 97, 107) and an optically effective imaging structure (29, 43, 50, 60, 70, 80a, 80b, 95, 105), by means of which information (94, 115) of the information structure (27, 45, 97, 107) is dependent a predetermined condition can be read, characterized in that the imaging structure (29, 43, 50, 60, 70, 80a, 80b, 95, 105) by means of a number of light guide elements (37, 46, 51a, 51b, 51c, 61, 71 , 81a, 81b, 96, 111), wherein a light guide element (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81 b, 96, 111) is located between one of the information structures (27, 45, 97 , 107) facing and one end facing away from the information structure (27, 45, 97, 107), and for specifying the predetermined condition along its extension a finite angle (ε) to the lateral extension (25, 49, 65, 83, 99, 109).

2. Security feature according to claim 1, characterized in that the light guide element (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) along its extent a fixed angle (ε) to the lateral extent (25 , 49, 65, 83, 99, 109).

3. Security feature according to claim 1 or 2, characterized in that the number of light guide elements (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) parallel to each other with a fixed angle (ε) to lateral extent

(25, 49, 65, 83, 99, 109).

4. Security feature according to one of claims 1 to 3, characterized in that the angle (ε) is between 30 ° and 90 °.

5. Security feature according to one of claims 1 to 4, characterized in that the number of light guide elements (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) is formed by an optical fiber bundle. *

6. Security feature according to one of claims 1 to 5, characterized in that the number of light guide elements (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) is embedded in filler material, the filler material through a document material and / or through the reflective properties of a boundary layer

(48, 63, 113) of an optical waveguide element (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) is formed.

7. Security feature according to one of claims 1 to 6, characterized in that the light guide element (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) has a length (I) which is between 50 μm and 1000 μm.

8. Security feature according to one of claims 1 to 7, characterized in that the light guide element (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) has a diameter (d) which is between 5 μm and 50 μm.

9. Security feature according to one of claims 1 to 8, characterized in that the number of light guide elements (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) in the lateral extent (25, 49 , 65, 83, 99, 109) of the feature (21, 41, 91, 101) relative to one another, according to a regular characteristic (85a, 85b).

10. Security feature according to claim 9, _v characterized in that the characteristic (85a, 85b) of the map structure (29, 43, 50, 60, 70, 80a, 80b, 95, 105) the read-out information (94, 115) of the information structural - tur (27, 45, 97, 107) is superimposed.

11. Security feature according to claim 9, characterized in that the characteristic (85a, 85b) of the mapping structure (29, 43, 50, 60, 70, 80a, 80b, 95, 105) the information (94, 115) of the information structure (27 , 45, 97, 107) itself is superimposed.

12. Security feature according to one of claims 1 to 11, characterized in that the information structure (27, 45, 97, 107) within a first layer and / or the optically effective imaging structure (29, 43, 50, 60, 70, 80a, 80b,

95, 105) is housed within a second layer along the lateral extent (25, 49, 65, 83, 99, 109).

13. Security feature according to claim 12, characterized in that additional optical imaging elements with a lens and / or diaphragm effect are provided, in particular that a diaphragm (117) surrounding the information (115) is arranged as an additional optical imaging element in the first layer (103) ,

14. Document (20, 40, 90, 100) with a security feature (21, 41, 91, 101) according to one of claims 1 to 13.

15. Document according to claim 14, characterized in that the security feature (21, 41, 91, 101) is accommodated at least inside the document.

16. Document according to claim 14 or 15, characterized by an at least in the area of a lateral extent (25, 49, 65, 83, 99, 109) of the security feature (21, 41, 91, 101) optically transparent area.

17. A method for producing a security feature (21, 41, 91, 101) according to any one of claims 1 to 13, wherein a carrier (23, 47, 93, 103) is provided, and An information structure (27, 45, 97, 107) is applied along a lateral extension (25, 49, 65, 83, 99, 109) on the carrier (23, 47, 93, 103), which is used to hold information (94 , 115) is suitable, and an optically effective imaging structure (29, 43, 50, 60, 70, 80a, 80b, 95, 105) is applied to the information structure (27, 45, 97, 107) by means of which

Information (94, 115) of the information structure (27, 45, 97, 107) can be read out depending on a predetermined condition, characterized in that the mapping structure (29, 43, 50, 60, 70, 80a, 80b, 95, 105) in the form of a number of light guide elements (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111), the number of light guide elements (37, 46, 51a , 51b, 51c, 61, 71, 81a, 81b, 96, 111) is separated from an optical fiber bundle at a finite cutting angle to the axis of the optical fiber bundle, and the imaging structure (29, 43, 50, 60, 70, 80a, 80b , 95, 105) is applied to the information structure (27, 45, 97, 107), with a light guide element (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) between one of the Information structure (27, 45, 97, 107) facing and one end facing away from the information structure (27, 45, 97, 107), and along its extension an over de n separation angle defines a finite angle (ε) to the lateral extension (25, 49, 65, 83, 99, 109).

18. A method for producing a security feature according to claim 17, characterized in that the number of light guide elements (37, 46, 51a, 51b, 51c, 61, 71, 81a, 81b, 96, 111) in the lateral extent (25, 49 , 65, 83, 99, 109) of the feature (21, 41, 91, 101) relative to one another, is arranged according to a regular characteristic (85a, 85b) and the information (94, 115) through the optically effective imaging structure (29,

43, 60, 70, 80a, 80b, 95, 105) is introduced into the information structure (27, 45, 97, 107) so that the characteristic (85a, 85b) of the mapping structure (29, 43, 50, 60 , 70, 80a, 80b, 95, 105) is superimposed on the information (94, 115) of the information structure (27, 45, 97, 107) itself.

19. A method for attaching a security feature (21, 41, 91, 101) to a document (20, 40, 90, 100), wherein either the security feature (21, 41, 91, 101) according to the manufacturing method according to claim 17 or 18 is produced and as such on the document

(20, 40, 90, 100) is attached, or a carrier (23, 47, 93 ^' , 103) is provided on a document (20, 40, 90, 100) and the security feature (21, 41, 91, 101 ) is produced on the document (20, 40, 90, 100) according to the production method according to claim 17 or 18.

20. A method for checking the authenticity of a document (20, 40, 90, 100) according to one of claims 14 to 16 with a security feature (21, 41, 91, 101), characterized in that an optically variable effect is achieved depending on the predetermined condition is so that the information (94, 115) is read out in a certain quality in the direction of the finite angle (ε) and the information (94, 115) is read out with changed quality with increasing deviation from the finite angle (ε).

21. A method for checking the authenticity according to claim 20, characterized in that with increasing deviation (33, 35) from the finite angle (ε) the information (94, 115) is read out with decreasing quality.

22. A method for checking the authenticity according to claim 20 or 21, characterized in that the predetermined condition in the form of irradiation and / or viewing of the document is realized from a direction (33, 35) defined to the finite angle (ε).

23. Method for checking the authenticity according to one of claims 20 to 22, characterized in that the optically variable effect is realized in the form of a contrast and / or difference in brightness.