EP3984762B1 - Method of manufacturing of a security feature - Google Patents

Description

The invention relates to a method for producing a security element with a security element body in which a window area is formed. The security element can be a semi-finished product for the production of security documents or a security document itself.

A feature that is intended to prevent imitation, falsification, unauthorized manufacture and/or guarantee the authenticity and integrity of the item is referred to as security features. A physical object that has such a feature is called a security element. Typical security elements include holograms, security threads, but also complete security documents or security document blanks.

For a class of security features and security elements, it is intended to check and/or verify them optically, i.e. by means of a visual inspection, the capture of images and their evaluation and/or other optical methods. Different optical features can be used and/or checked.

One such optical feature is, for example, the ability to transmit light. Materials through which light can pass almost unhindered, such as clear window panes, are referred to as transparent in the context described here. This means that images according to the geometric optics are possible through the material. This can optionally be limited to a specific wavelength range of the human-visible spectral range. This is the case, for example, with colored clear glass or plastic.

Material that has a high transmission of light, but scatters it diffusely internally, is referred to here as translucent.

In the area of security documents, printed, filled plastic cards are usually referred to as opaque. Nevertheless, such objects also generally have a certain transmission of light when viewed in front of a light source, so that the light source is located behind the security element in the viewing direction.

In connection with what is described here, a distinction is made between transparent material and non-transparent material, which includes both opaque and translucent material.

Modern security documents that have one or more non-transparent material layers and/or printing sometimes have a so-called window in which the material is completely transparent in volume from a top to a bottom. Markings introduced, for example in the form of local blackening through laser marking and a partial imprint of individual alphanumeric characters or pixels on the inside, fundamentally do not change the property that it is a window. However, surface overprinting of volume-transparent material by non-transparent material or coverings by non-transparent material layers leads to the corresponding covered or area-overprinted area being viewed as a non-transparent area of the corresponding security element.

An example of a security document with a window area is, for example, in the DE 10 2016 203 609 A1 described.

EP 2 384 901 A1 describes a method according to the preamble of claim 1 and a substrate for the production of valuable documents, comprising a first layer with a first transmittance, which has at least one recess, in the area of which the first layer has a second transmittance, which is greater than the first transmittance is, wherein on a back and / or on a front of the substrate an opaque layer is applied, which has a third transmittance, which is smaller than the second transmittance. E corresponding value documents are also described.

US 4,710,614 describes a security document comprising a substrate containing at least one optical fiber, at least one end of which is flush with a surface of the substrate, to enable authentication of the document by a test based on exposing the document to an electromagnetic source Exposed to radiation while observing the radiation transmitted to both ends of the optical fiber. The optical fiber has a transparent coating and is located at a depth within the substrate of at least one surface of the substrate that is not greater than the penetration depth of the electromagnetic radiation into the substrate. The radiation that penetrates the substrate to the optical fiber is trapped in the optical fiber and transmitted to at least one end where it is observed to authenticate the document.

WO 2019/077316 A1 describes a security document with a window area and a non-window area. The window area is of lower opacity than the non-window area. The security document includes a transparent polymer layer at least in the window area of the security document, and the transparent polymer layer includes an internal laser marking therein that has an optical effect.

WO 2008/031170 A1 describes a security document and a method for producing a security document in which a radiation curable ink is applied to at least one side of a substrate containing at least one area of transparent plastic material that forms a window or half-window area. The ink is embossed while soft and cured with radiation to form an embossed security device within the window or half-window area that includes one or more diffractive structures, a lens structure, or other security elements having a relief structure.

In addition to very complex security features that require a lot of effort for verification, there is always a need to integrate security features that are easy to check into security elements. The invention is therefore based on the object of creating a method for producing a security element with which a security feature that is easy to verify but not easy to replicate is formed.

The invention is achieved according to the invention by a method with the features of patent claim 1. Advantageous embodiments of the invention result from the subclaims.

Basic idea of the invention

The invention is based on the general idea of creating a volume area made of transparent material inside the security element, which on the one hand is one of the The top side forms a window area extending to an opposite bottom side of the security element body, but between the top side and the opposite bottom side it has an expansion in cross-section inside that is larger than the cross-sectional areas of the window area of the top side and the bottom side, which are designed to be aligned with one another. This makes it possible for light that passes through the window area to partially reach the area, which is referred to here as the window bracket, which is covered translucently on the top and bottom, so that this transparent area cannot be seen in a top view.

A top view refers to an observation and/or the capture of an image in which illumination and capture take place from the same side of the security element. A transmitted light observation, on the other hand, is an observation or capture of an image of the security element, in which the light source is located on the side of the security element facing the capture. When viewing through transmitted light, light is irradiated onto the surface facing away from the viewer or the optical detection device and the light that is transmitted through the security element body is detected. Because the security element body comprises transparent material in the area of the window arm, the transmission through the security element body in the area of the window arm is increased compared to other areas, if there is any transmission of light through the security element body at all. These statements also apply if the window area is covered when viewed, so that no light inside the security element body can reach the window arm through the window area. If light is also irradiated through the window area in addition or at the same time, the window cantilever stands out even more strongly with suitable lighting and viewing directions, i.e. as a contrast difference in the security element body in the window cantilever area relative to the other non-transparent areas adjacent to the window area and/or the window cantilever area.

Definitions

The window area is the area on a surface of the security element body through which a view through the security element body is possible. through the transparent material inside to the opposite side is possible. Areas in which this is not possible are referred to as non-transparent areas of the security element body. That non-transparent area under which there is transparent material inside the window bracket, ie transparent material connected to the viewing window, is referred to as the bracket area.

A transparent material is the material that is clear in volume, possibly colored, but through which imaging according to geometric optics with light of at least one wavelength in the visible, i.e. perceptible to humans, wavelength range is possible.

Through a window area, imaging according to geometric optics is therefore possible at least for light of some wavelengths in the visible wavelength range if the window area is clear and colored, or for all wavelengths of the visible wavelength range if the transparent material that forms the window area is not colored .

Transmission of light through a material layer or through a body is the process of light passing or passing through the material layer or the body, whereby the light can be scattered in the material layer or the body in the sense of classical optics.

The transmittance of a material layer or a body is the ratio of the intensity of the light transmitted by the material layer or the body to the light intensity irradiated onto the material layer or the body. The term transmission is sometimes used as a synonym for the degree of transmission if the process of transmission is viewed as a measurable quantity.

Preferred Embodiments

In particular, by means of the method according to the invention, a security element with a security element body is created which has a window area in which the material of the security element body is transparent between a top and a bottom, the window area being circumferentially surrounded by a non-transparent area of the
Security element body is surrounded and limited, with the window area merging into a transparent window cantilever which extends into the non-transparent area, but the window cantilever is completely non-transparently covered both to the top and to the bottom of the security element body. A method for producing a security element is thus created, which comprises a security element body with a window area extending from a top to a bottom, which is formed from transparent material which merges into a window bracket, the transparent material of which extends to the top and to the bottom is covered completely non-transparently, comprising: providing a core layer that is non-transparent at least in a surface section; Introducing a recess in the core layer within the non-transparent surface section, so that the recess is surrounded all around by a non-transparent part of the surface section; inserting transparent material into the recess; non-transparently covering a cantilever portion of the recess to the top and bottom and applying heat to form the security element body. The core layer itself can consist of a plastic material or can be a composite of several material layers into which, for example, other elements and security features are integrated.

1. (a) zunächst ein erster Aussparungsabschnitt ausgebildet wird, der den Fensterauslegerabschnitt und ein Teil des Fensterbereichs umfasst,
2. (b) in den ersten Aussparungsabschnitt transparentes Material eingefügt wird, welches den Fensterauslegerabschnitt ausfüllt und eine Grenzlinie zwischen dem Fensterauslegerabschnitt und dem Fensterbereich vollständig überdeckt, und
3. (c) der Fensterauslegerabschnitt mindestens zu der Oberseite durch eine im Bereich des Fensterauslegerabschnitts nichttransparente obere Abdeckschicht und/oder an der Unterseite durch eine im Bereich des Fensterauslegerabschnitts nichttransparente untere Abdeckschicht abgedeckt wird, und
4. (d) die Kernschicht das eingefüllte transparente Material und die obere Abdeckschicht und/oder die untere Abdeckschicht punktuell miteinander verbunden werden, und
5. (e) anschließend die Aussparung der Kernschicht erweitert wird, sodass die Kernschicht im Fensterbereich der Aussparung frei von Material ist, wobei zeitgleich in die obere Abdeckschicht und/oder die untere Abdeckschicht ebenfalls Aussparungen eingebracht werden, die mit dem Fensterbereich der Aussparung in der Kernschicht fluchten, und
6. (f) Einbringen von transparentem Material zum bündigen Verfüllen der Aussparung.

According to the invention it is further provided that the introduction of the recess into the core layer and the filling with transparent material takes place in several processes or process steps, which include:

1. (a) a first recess section is first formed, which includes the window arm section and part of the window area,
2. (b) transparent material is inserted into the first recess section, which fills the window bracket section and completely covers a boundary line between the window bracket section and the window area, and
3. (c) the window cantilever section is covered at least on the top by an upper cover layer that is non-transparent in the area of the window cantilever section and/or on the underside by a lower cover layer that is non-transparent in the area of the window cantilever section, and
4. (d) the core layer, the filled transparent material and the upper cover layer and / or the lower cover layer are connected to one another at points, and
5. (e) the recess in the core layer is then expanded so that the core layer is free of material in the window area of the recess, whereby At the same time, recesses are also made in the upper cover layer and / or the lower cover layer, which are aligned with the window area of the recess in the core layer, and
6. (f) Introducing transparent material to fill the recess flush.

According to the invention, it is ensured that the non-transparent material layers surrounding the window area, for example the upper cover layer and/or the lower cover layer, have the same recess cross section as the window area of the core layer. In addition, a good, secure connection to the transparent material of the window bracket is achieved, which is initially inserted so that it partially protrudes into the window area. When expanding the core layer recess, in addition to the non-transparent material of the core layer, that part of the transparent material of the cantilever section that protrudes beyond the boundary lines into the window area is also removed from the window area, so that an optimal connection of the transparent material of the cantilever section with the and located in the window area transparent material inserted therein is produced.

It is therefore particularly preferred that the security element body has at least one non-transparent core layer with a recess which encloses the window area but is larger than the window area. In the finished security element body, the material of the window area, which is transparent in volume, also extends into a so-called window cantilever section of the recess in the core layer. This window bracket area is not completely transparently covered on both the top and bottom of the security element body. The contour of the recess can partially be the outer contour of the window area, but is "larger" than the window area at least in one area.

A good and simple covering of the window arm to the top and/or the bottom can be achieved in an embodiment in which it is provided that the window arm is covered on the top by an upper cover layer that is non-transparent in volume and/or on the underside by a lower cover layer that is non-transparent in volume is. The cover layer used here is a self-supporting layer before it is connected to the core layer and the material of the window bracket viewed. A pure printing layer, made of ink or printing ink, which is not independently load-bearing is not considered a cover layer in the sense of what is described here.

In other embodiments, it can be provided that the window arm is covered on the top by a non-transparent upper coating and/or on the underside by a non-transparent lower coating. Coatings can be applied, for example, by vapor deposition or by any printing process. For example, the covering can be done by an upper covering pressure or a lower covering pressure. Here, the cover prints or the cover coatings are aligned with one another at a boundary line between the window area and the window bracket. This means that in a vertical plan view, or if the boundaries of the window area are otherwise aligned with respect to another preferred direction, the cover coatings are aligned with one another with respect to the normal or the other preferred direction. When looking at the window area, the window arm can only be recognized if part of the inner wall is transparent and not opaque. The same applies to the upper and lower cover layers, which are also aligned at the boundary line between the window area and the cantilever area with respect to the surface normal or a preferred direction with respect to which the boundary of the window area is aligned.

In order to produce such a security element body, process steps (a) to (f) of the process according to the invention are suitable.

The introduction of the transparent material into the cantilever section in method step (b) is preferably carried out by means of a one-piece cantilever insert. Additionally or alternatively, the transparent material is inserted in process step (f) by means of a one-piece window plug. In both cases it is ensured that the corresponding recess or a section/area can be reliably filled in a simple manner in the former case of the cantilever section and in the latter case of the window area. In particular, if the security element or the security element body is a laminated body which consists of more than the core layer and optionally an upper and/or lower cover layer, preferred embodiments provide for the core layer to be applied before and/or after method step (c). the top or the bottom is covered with one or more further layers and for process steps (d), (e) and (f) are carried out as for the upper cover layer and / or the lower cover layer. There can therefore be additional layers stacked on top of each other and connected to each other at points in order to provide them with the recess for the window area at the same time as the other layers. This is preferably done in a punching process.

In a preferred embodiment, recesses are not made parallel to the surface normal of the respective layers, but rather obliquely. In this way, it can be achieved that inserted transparent material pieces, such as the cantilever insert or the window plug, are held despite gravity when assembled in the respective layers, the surfaces of which are oriented, for example, parallel to the earth's surface. This makes handling easier.

Even more preferably, the material processing is carried out in such a way that the recesses created have beveled side walls, for example conically tapering along the direction of introduction transversely to the surface of the material layer. Such recesses with side or boundary walls that are beveled relative to a surface normal of the material layer or the topmost material layer in the case of several material layers stacked on top of one another and/or tapered along the recess depth can be produced using laser processing or water jet techniques. Correspondingly adapted pieces of material that are inserted can be optimally held in the recesses during production. It goes without saying that the inserted pieces of material, such as the cantilever insert or the window plug, have correspondingly adapted sloping or tapering outer walls along their material thickness, so that an optimal positive fit takes place when inserted into the formed recesses. Pieces of material to be inserted can, for example, be designed as injection molded parts.

Pieces of material that are inserted into recesses with sloping or funnel-shaped side surfaces generally do not need to be secured by stapling (for example, adjacent layers to the layer containing the recess or to the layer in which they are inserted) and are only secured in a final letterpress print -High-temperature lamination process cohesively integrated into the document body.

The individual components are preferably put together to form the laminated body in such a way that heat is introduced and pressure is applied a lamination press to connect the transparent material to the core layer and the upper cover layer and/or the lower cover layer to form the security element body. If further material layers are present, they are also connected to the security element body in this lamination step in the lamination press.

Particularly preferred are the contours of the recesses in the upper cover layer, the lower cover layer and the core layer, which define the window area, coordinated with one another in such a way that in at least one contour section in which there is no window bracket area adjacent to the window area, at every point on an edge of the Recess in the upper cover layer has a straight line to a corresponding point on an edge of the lower cover layer, the course of which coincides with the contour of the core section. In this contour section, the recesses are aligned with one another, regardless of whether the outer contour of the transparent window area in the contour section is perpendicular to the outer surface of the security element body, obliquely, conically tapered or widened from the top of the security document body to an underside. This orientation can also be different in subsections of the at least one contour section. For verification, it is crucial that the alignment of the upper cover layer with the core layer and with the lower cover layer along the contour section can be checked at every point of the at least one contour section.

Preferably there is a point in the transparent window area relative to which this at least one contour section covers an angular range of more than 180°, more preferably more than 210°, even more preferably more than 225° of the contour of the window area.

Particularly preferably there is only one contour section in which there is no window bracket area next to the window area. In such a preferred embodiment, this contour section, supplemented by a transition section, results in the circumferential contour of the window area. The transition section is the section of the window contour in which the transparent material of the window area merges into the window bracket area. Preferably there is only one transition section in the contour of the window area. The length of the

Transition section of the circumferential contour of the window area is preferably less than a quarter of the length of the entire circumferential contour of the window area.

The security element body can represent a semi-finished product or a finished security document. If this is produced as a semi-finished product, it is preferred that one or more volume-transparent additional layers are applied to the top and/or the bottom, which serve, for example, as protective layers or contain further security features, such as a hologram or the like.

A verification of one of the security elements described with a window area that merges into a hidden window arm, for example a security element designed as a security document, is carried out according to an unclaimed embodiment of a verification method by shining verification light into the window area of the security element, at least one image of the top or the Underside is detected, which includes at least an area next to the window area, and the image is examined for differences in brightness in the area next to the window area, the security element being classified as genuine if an area with increased brightness is found that is adjacent to the window area and the verification decision is issued. The output can take place, for example, in the form of a signal. For example, the signal can be used to control an access device such as a door lock or a turnstile. The verification light can be, for example, the light of a flashlight or the like.

In a development that is also not claimed, a reference image of the corresponding top or bottom is recorded while no verification light, that is, preferably no light at all, is irradiated into the window area or, alternatively, no light is irradiated into the window area in addition to the ambient light, that is, only ambient light is incident, and at After evaluating the at least one image, a difference is first formed with the reference image and the differences in brightness are determined in the difference image, the security element only being classified as genuine if an area with increased brightness is found in the difference image, which is adjacent to the window area.

In a likewise unclaimed embodiment, the image is captured from the side from which the verification light is also irradiated. In this way, simple transmitted light effects, which can be attributed to the absorption of a security element varying across the surface, can be reliably distinguished from the effect caused by a window boom.

In alternative embodiments, which are also not claimed, the image is captured on the side of the security element that is opposite the side over which the verification light is irradiated. If the verification light is shined over the top, the image is captured from the bottom and vice versa. Here too, a reference image can be captured and included in the evaluation.

A further development, which is also not claimed, analyzes the shape of the area with increased brightness and compares it with predetermined shapes. If the shape matches a predetermined shape, the security element is classified as genuine, otherwise as not genuine. In a further development, security elements can be differentiated into groups or classes based on their correspondence to one of the specified forms and assigned to them.

If the at least one image is captured from the side that is opposite the side over which the verification light is irradiated, if a light cone of the verification light or an irradiation area of the verification light covers the contour section of the window area completely or in sections, it can be checked in the image whether the recesses in the core layer and the cover layers are aligned with one another. In this case, there are no brightness fluctuations in the contour except in the transition area into the window bracket(s).

The verification light preferably has a higher light intensity, preferably at least an integer factor higher, than the ambient light striking the rest of the outside during the capture of the at least one image.

The verification light is preferably irradiated only into the window area or into the window area and at the same time into the smallest possible area around the window area. A flashlight or flashlight is preferably placed on one outside so that the verification light radiation is, if possible, only in the window area or areas around the window area in which no window cantilever is expected or which should not be evaluated for the presence of a window cantilever. In order to verify the entire surroundings of the window area, the verification can be carried out one after the other for different areas adjacent to the window area while changing the verification light irradiation. The light source particularly preferably has a light exit surface whose shape is adapted to the shape of the window area. It can either be smaller or equal to the area, or slightly larger so that the surrounding contour of the window area is also illuminated.

Still other embodiments provide that the security element has a different transmittance between the top and the window bracket area than between the bottom and the window bracket area. In order to verify this property, the verification is carried out once by capturing the at least one image from the top and once by capturing the at least one image from the bottom. The side of the irradiation of the verification light is also changed accordingly. Based on the differences in brightness, with otherwise identical irradiation of the verification light, it can be checked whether the determined areas with increased brightness have a difference in brightness. If this is the case, the security element is verified as genuine if such a difference in brightness is expected, otherwise as false. The difference in brightness between the two compared areas with increased brightness can also be evaluated and compared with specifications.

In the latter type of evaluation and verification, which is also not required, it can also be checked whether the window arm can be detected from both sides or only from one side. This feature can also be used for verification, depending on how the real security element is designed.

It is understood by the person skilled in the art that the window bracket area is not transparently covered at least on the top or bottom in such a way that a minimum level of transmission for verification light exists, so that an area of increased brightness during verification via radiation of verification light into the window area is detectable.

Fig. 1

eine schematische Draufsicht auf ein Sicherheitselement;

Fig. 2

eine schematische Schnittansicht durch ein Sicherheitselement nach Fig. 1;

Fig. 3

eine schematische Draufsicht auf die Unterseite des Sicherheitselements nach Fig. 1 und Fig. 2;

Fig. 4

eine schematische Schnittansicht durch eine weitere Ausführungsform eines Sicherheitselements;

Fig. 5

eine weitere schematische Schnittansicht noch eines anderen Sicherheitselements;

Fig. 6

eine schematische Explosionszeichnung eines Sicherheitselements;

Fig. 7

eine weitere Explosionszeichnung eines anderen Sicherheitselements;

Fig. 8

eine schematische Draufsicht auf ein sich ergebendes Sicherheitsdokument mit einem Fensterbereich; und

Fig. 9

ein Ablaufdiagramm eines Verifikationsverfahrens zum Verifizieren eines Sicherheitselements mit einem verborgenen Fensterausleger.

The invention is explained in more detail below with reference to a drawing. Show here:

Fig. 1

a schematic top view of a security element;

Fig. 2

a schematic sectional view through a security element Fig. 1 ;

Fig. 3

a schematic top view of the underside of the security element Fig. 1 and Fig. 2 ;

Fig. 4

a schematic sectional view through a further embodiment of a security element;

Fig. 5

a further schematic sectional view of yet another security element;

Fig. 6

a schematic exploded drawing of a security element;

Fig. 7

another exploded view of another security element;

Fig. 8

a schematic top view of a resulting security document with a window area; and

Fig. 9

a flowchart of a verification method for verifying a security element with a hidden window bracket.

In Fig. 1 A top view of a security element 1 is shown schematically. The security element 1 is designed as a security document 10. The security element 1 has a non-transparent area 26 which completely encloses and delimits a window area 25. In the non-transparent area 26, the security element 1 is “opaque”. In the window area 25, however, it is designed to be transparent from a top side 21 to a bottom side 22, which faces the plane of the drawing, so that it is possible to see the information underneath through the window area 25.

Inside the security element 1, which has a security element body 20, a window arm is formed, which consists of transparent material, which merges into the transparent material 51 of the window area 25. The window boom 60, which is located inside the boom area 27, is not transparently covered from the top 21 or the bottom 22. Therefore, the window bracket 60 is only shown in dashed lines in this view, since it cannot be seen from the top 21 or the bottom 22 when viewed from above due to the non-transparent cover. However, if the security element 1 is arranged in front of a light source and viewed from the side facing away from the light source, a transmission in the display area 27 is generally greater than in the rest of the non-transparent area 26. This is further increased when light enters the window area 25 and partially reaches the window bracket 60 through the transparent material 51 inside.

The same technical features are given the same reference numbers in all figures. The specific deviations from the previously described examples and figures are described. In Fig. 2 is a schematic sectional view through the security element 1 Fig. 1 shown. The transparent material 51 in the window area 25, which merges into the window bracket 60, can be clearly seen. This is covered by an upper cover layer 70 to the top 21 and by the lower cover layer 80 to the bottom 22. The boom area is therefore not immediately visible when the security element 1 is viewed from above. The recesses 73 in the upper cover layer 70 and 83 in the lower cover layer 80 are identical to a window area 42 of the recess 40, which, however, is larger and additionally includes the offshoot section 41 in the core layer 30, which is designed to be non-transparent. Thus, the core layer 30, the upper cover layer 100 and the lower cover layer 110 are all three non-transparent. The window 50 in the window area 25 and the boom 60 in the boom area 26, however, are made of transparent material. The transparent material in the area of the boom 60 does not have to be identical to the transparent material in the window area 25. However, it is necessary that this material flows into each other without a gap. This enables light to pass from the window 50 into the window arm 60. As a rule, however, it will be the same material, in particular a transparent plastic material, particularly preferably polycarbonate. The core layer 30 and the upper cover layer 70 and the lower cover layer 80 are also preferably made of a plastic material, particularly preferably made of the same material as the window 50 and the window bracket 60. Polycarbonate is particularly preferred here. However, any other plastics and also fiber-reinforced plastics can also be used. Both the core layer and the upper cover layer 70 or the lower cover layer 80 can be designed in multiple layers, that is to say they can in turn be composite products made up of several layers or layers. These can also contain a variety of different security features and/or security elements.

In Fig. 3 is the schematic top view of the underside of the security element 1 Fig. 1 and Fig. 2 shown. Here too, the non-transparent area 26 can be seen, which covers the boom area and encloses and delimits the window area 25. The underside 22 of the security element 1 is also non-transparent in the boom area 27.

In Fig. 4 is a sectional view of another security element 1 shown schematically. This includes a core layer 30 with a recess 40, which is filled with transparent material 51. The core layer is designed to be non-transparent, preferably opaque. The transparent material 51 is covered in a non-transparent manner in the cantilever section 41 of the recess 40 on the top 21 by an upper coating 100, for example an upper cover print 101, and on the underside 22 by a lower coating 110, for example a lower cover print 111. When viewing the security element 1 from the top 21, the window arm 60 cannot be seen because it is not transparently hidden by the non-transparent upper coating 100 and when viewed from the bottom 22 by the lower coating 110. When viewed in transmitted light, however, depending on the choice of coating, there is usually a higher transmission in the area of the display section 27 than in the remaining non-transparent area 28 of the non-transparent area 26 of the security element 1. In addition, light entering the window area 25 penetrates, also get into the window boom 60 and thus increase the visibility of the window boom 60 or the boom area 27.

In Fig. 5 Another example of a security element is shown schematically. This differs from the example below Fig. 4 as a result of that the upper coating 100 for covering and the lower coating 110 for covering are each applied to a transparent upper protective layer 150 and a lower protective layer 160, respectively. The printing to form one of the coatings 100, 110 on the upper or lower protective layer 150, 160 can either be on the side facing the core layer 30, as shown for the lower protective layer 160, or on the side facing away from the core layer 30, as for the upper protective layer 150 shown can be applied. The security elements 1 shown in the figures are preferably security document blanks, which are connected with further layers to form a security document body. However, they can also be ready-made security documents.

In Fig. 6 a schematic exploded drawing of a security element designed as a security document is shown. A core layer 30 has a recess 40 with a window area 42 and a cantilever section 41. The display area 40 is filled with transparent material in the form of a cantilever insert 61, the cantilever insert being made of transparent material and being slightly larger than the cantilever section of the recess 40. A part of the cantilever insert 61 thus projects into the window area of the recess or the future window area. Towards an upper side, the core layer 30 and the window support insert 61 are covered with a data information layer 90, which is not transparent over the entire surface. These are connected to each other at points. The recess 40 is then expanded so that the window area receives its final shape. At the same time, an information layer recess 94 is created in the information layer. Their edges are aligned with the window area 42 of the recess 40 in the core layer 30. Part of the window cantilever insert 61 is also separated in order to ensure a clean connection between the transparent material of the window cantilever 60 and the material that forms the window area 42 of the recess 40 and the Window recess 94 in the information layer 90 is filled. Here, a transparent window plug 53 is inserted simultaneously into the information layer 90 and the core layer 30 or its window recesses 94, 42. In addition, an upper intermediate layer 180 and a lower intermediate layer 190 are joined together with the core layer 30 and the information layer 90, with a non-transparent print 192 being applied to the lower intermediate layer 190, which precisely leaves out the window area 25. An upper protective layer 150 is provided on an upper side 21 and a lower protective layer 160 is provided on the underside 22. All these layers are rolled into one final lamination step heated and combined to form a security element body.

In an alternative example, similar to the information side 90, a material layer that is not transparent in volume could also be provided below the core layer 30, into which a window recess is introduced at the same time as the recess 40 of the core layer is expanded and the window recess 94 of the information layer is introduced, after this further Layer has also been connected at points to the others before the recess is formed.

In Fig. 7 a further exploded drawing of another example of a security document not according to the invention is shown schematically. In this example, the information layer 90 is also the core layer 30, into which the recess 40 is made. This includes the window area 42 and the display section 41. The recess is filled with a one-piece transparent window bracket insert 61. A transparent upper intermediate layer 180, which is not printed transparently at least in the cantilever area 27, and an upper transparent protective layer 150 are arranged on the top. Under the information layer 90 is a printed further lower intermediate layer 190, which is provided with an imprint 192, so that the intermediate layer 190 is not printed translucently at least in the cantilever area 27 and is not printed in the window area 25, as well as a lower protective layer 160. All layers are bonded together to form the security element body, which is then a security document body.

In another example not according to the invention, the upper intermediate layer and the further lower intermediate layer can be saved and the cantilever area can be overprinted on the protective layer of the upper protective layer or the transparent insert directly or towards the underside on the intermediate layer, the cantilever or the lower protective layer.

In Fig. 8 is a schematic top view of a resulting security document 10 with a window area 25 shown schematically together with an enlarged section of the window 50, in which an extension 62 of the window arm 60, which extends into the non-transparent area of the security element, can be seen.

Even if the recesses in the various examples shown have side or boundary surfaces that are oriented perpendicular to the surfaces of the individual different layers, this is primarily due to a simplified representation. Although recesses with vertically oriented side surfaces represent possible embodiments, recesses that are designed with oblique, in particular tapering, side surfaces are preferred. As a result, preferably one-piece pieces of material to be inserted to fill the recess can be optimally held during production. These have correspondingly adapted sloping or also tapering side surfaces.

in Fig. 9 a flowchart of an unclaimed verification method is shown as an example.
Optional features are shown in dashed lines. Optionally, a reference image of a bottom side of a security element, for example a security document as in Fig. 8 , recorded. Alternatively or additionally, the reference image or a further reference image could also be captured from the top. No verification light is emitted here. However, the security element can be uniformly illuminated with ambient light.

Verification light is then irradiated into the window area 210, the intensity of which is higher than the intensity of the ambient light, if such is present. The irradiation takes place, for example, via the top. Alternatively, it could also be done via the underside of the security element.

At least one image of the security element is then captured 220, which includes at least an area next to the window area, preferably additionally the window area. When a reference image is captured, the image is captured from the page from which the reference image was captured. This can be the side from which the light was irradiated or the opposite side.

The at least one image is evaluated for differences in brightness in an area adjacent to the window area and an area or areas of increased brightness are searched for that border the window area 230. Was a Reference image is recorded, a difference image is formed during evaluation and the brightness differences in the difference image are examined 240.

It is checked whether one or more areas with increased brightness were found 250 that merge into the window area.

Based on a result of the test, a classification of the security element is made 260. For example, the security element is classified as genuine if an area of increased brightness was found that merges into the window area, and otherwise as not genuine.

A verification decision based on the classification is issued 270. This can be used, for example, to control an access device.

Optionally, the shape of the area with increased brightness can be determined 280 and compared with a predetermined shape or several predetermined shapes 290. The result of this comparison can be taken into account in the classification 260. For example, if there is no match with the predetermined shape or one of the several predetermined shapes, the security element is classified as not genuine.

An additional verification step can provide that the verification light is irradiated during the capture of the at least one image or during the capture of a further image 300 in such a way that a narrow strip of the area around the window area is irradiated with the verification light along at least one contour section of the window area. The window contour is now examined for brightness fluctuations outside a transition area from areas of increased brightness to the window area 310. If these are found, this is an indication that the recesses in the core layer and covers, e.g. the cover layers, are not aligned. A document is then also classified as inauthentic in step 260 if such brightness fluctuations are found.

Further investigations can be included in the verification. For example, the same scan can be performed on both sides of the security element.

The verification can be carried out from one side, i.e. with the irradiation of the verification light and the capture of the at least one image from the same side of the security element. This examination is particularly advantageous for detecting apparent falsifications that can simulate a similar effect in transmitted light. Only the examination of the contour of the window area is improved if it is carried out in such a way that the light is irradiated from the side that is opposite the side from which the at least one image is captured.

Examining whether the contours of the various recesses that define the window section are correctly aligned with one another, possibly in different directions in sections, can form an independent or supplementary verification method. This verification can also be carried out using other optical means, for example a magnifying glass or a microscope.

Reference symbol list

1

Security element

10

Security document

20

Security element body

21

Top

22

bottom

25

Window area

26

non-transparent area

27

Boom area

30

core layer

40

recess

41

Boom section

42

Window area of the recess

50

Window

51

transparent material

53

window plug

60

Window boom

61

Window bracket insert

62

Window bracket approach

70

top cover layer

73

Recess in the top cover layer

80

bottom cover layer

83

Recess in the bottom cover layer

90

Information layer

94

window recess

100

top coating

101

top cover pressure

110

bottom coating

111

lower cover pressure

150

upper protective layer

160

lower protective layer

180

upper intermediate layer

190

lower intermediate layer

192

non-transparent print

200

Capturing a reference image

210

Shining verification light into the window area

220

Capture at least one image

230

Evaluate the at least one figure

240

Forming a difference map and evaluating this difference map

250

Check whether an area with increased brightness exists

260

Classify the security element

270

Outputting a verification result

280

Determine a shape of the area of increased brightness

290

Comparing the shape with given shapes

300

Capturing another image

310

Examining the imaged window contour for brightness fluctuations

Claims (7)

1. Method of manufacturing a security element which comprises a

   security element body (20) having a window portion (25) extending from a upper side (21) to a lower side (22); formed of transparent material which merges into a window cantilever (60) whose transparent material is completely non-transparently covered to the upper side (21) and the lower side (22), comprising

   providing a core layer (30) which is non-transparent at least in a surface portion, inserting a recess (40) in the core layer (30) within the non-transparent areal portion so that the recess (40) is circumferentially enclosed by a non-transparent part of the areal portion, inserting transparent material into the recess (40);

   non-transparently covering a cantilever section of the recess (40) to the upper side (21) and to the lower side (22) and introducing heat to form the security element body (20),

   characterized in that

   the insertion of the recess (40) into the core layer (30) and the filling with transparent material are each performed in multiple operations, and

   (a) first forming a first recess section comprising the window cantilever section and a part of the window portion (25)

   (b) transparent material is inserted into the first recess section to fill the window boom portion and completely cover a boundary line between the window cantilever section and the window portion 25); and

   (c) the window cantilever section is covered at least to the upper side (21) by an upper covering layer (70) which is not transparent in the region of the window cantilever section (41) and/or at the lower side (22) by a lower covering layer (80) which is not transparent in the region of the window cantilever section (41); and

   (d) the core layer (30), the filled transparent material and the upper covering layer and/or the lower covering layer are connected to each other in a punctiform manner
   and

   (e) subsequently widening the recess (40) of the core layer (30) so that the core layer (30) is free of material in the window portion (25) of the recess (40), wherein at the same time recesses are also made in the upper covering layer (70) and/or the lower covering layer (80) which are aligned with the window portion (25) of the recess (40) in the core layer (30), and

   (f) introducing transparent material for flush filling of the recesses.
2. Method according to claim 1, characterized in that the transparent material is inserted in method step (b) by means of a one-piece cantilever insert and/or in method step (f) the transparent material is inserted by means of a one-piece window plug (53).
3. Method according to one of the claims 1 or 2, characterized in that the core layer (30) is covered before and/or after the method step (c) in each case on the upper side (21) and/or the lower side (22) with one or more further layers, for which the method steps (d), (e) and (f) are carried out as for the one upper covering layer (70) and/or the lower covering layer (80)
4. Process according to any one of claims 1 to 3, characterized in that the introduction of heat is carried out with a lamination press to bond the transparent material to the core layer (30) and the upper covering layer (70) and/or the lower covering layer (80) to form the security element body (20).
5. Method according to any one of claims 1 to 4, characterized in that one or more additional layers transparent in volume are additionally superimposed to the upper side (21) and/or the lower side (22).
6. Method according to any one of claims 1 to 5, characterized in that the recesses are created with beveled side walls.
7. Process according to claim 6, characterized in that the recesses are produced with side walls tapering conically along the direction of application transversely to the surface of the material layer.

Images