DE212012000264U1 - Security document with a translucent IR, magnetic or fluorescent motif - Google Patents

Abstract

Security document with at least one substrate layer (1a, 1b, 1c) that bears a translucent motif (5) that is formed by a combination of at least two dye layers (6a, 6b, 6c, 6d) that are on different sides of the substrate layer (1a , 1b, 1c), characterized in that the dye layers are selected from the group comprising: magnetic dye layers, IR dye layers and UV fluorescent dye layers.

Description

Technical area

The invention relates to a security document having a substrate layer carrying a translucent motif and a method for verifying such a security document.

background

It is known to apply translucent motifs to security documents, for example to banknotes or passports. Such motifs typically include dye layers of dark colors applied to opposite sides of a substrate layer. Upon reflection, only such a dye layer is visible, and the motif is not perceptible as a whole. However, when the document is viewed in transparency, both layers become visible and the subject can be perceived as a whole.

Disclosure of the invention

It is a basic object of the invention to provide a security document and a method of the kind specified above which provide improved security.

This object is solved by the document and the method according to the independent claims. A translucent motif is thus formed by a combination of at least two dye layers. Each dye layer is a magnetic dye layer and / or an IR dye layer and / or a UV fluorescent dye layer, and the two dye layers are disposed on different sides of the substrate layer.

By forming a translucent motif with magnetic dye layers and / or IR dye layers and / or UV fluorescent dye layers, the motif will receive at least some properties imperceptible to the human eye, making it less likely that the security feature will be successfully counterfeited , At the same time, the motif enjoys improved security resulting from the fact that the two dye layers must be printed aligned with each other, which is difficult without special security printing devices.

Advantageously, at least one of the dye layers forming the translucent motif is applied to a surface of the document which has the same coloration as the dye layer so that the dye layer is later imperceptible to the naked eye. This later makes it more difficult for a counterfeiter to detect the presence of the dye layer.

In another advantageous embodiment, the substrate comprises a plurality of substrate layers, wherein the dye layers are arranged between the substrate layers or on the outside thereof. This makes it possible to create a wide variety of complex, translucent motifs that are difficult to counterfeit.

Such substrate layers may be laminated to form the substrate. At least one of the dye layers of the motif may be disposed between two such substrate layers and / or on top of an uppermost substrate layer or on the underside of a lowermost substrate layer.

The substrate or the substrate layers may be, for example, paper layers or plastic layers.

The invention further relates to a method for checking the above security document. This method comprises the step of testing whether the at least two dye layers together make up the translucent motif in phantom.

Brief description of the drawings

The invention will be better understood and other advantages than those described above will be apparent from a reading of the following description. This description refers to the attached drawings, in which:

1 shows a plan view of a security document;

2 a sectional view taken along the line II-II in 1 shows (enlarged in the vertical direction),

3 a sectional view of another embodiment shows

4 a sectional view of a third embodiment shows

5 shows a plan view of a translucent code, and

6 a top view of a translucent text shows.

Embodiments of the invention

definitions:

A "magnetic dye layer" is a dye layer having a ferroelectric effect and / or having a DC magnetic permeability μ of at least 2.

An "IR dye layer" is a dye layer having an absorption of at least 30% at at least one wavelength between 770 nm and 10 μm.

A "UV fluorescent dye layer" is a dye layer which, when irradiated with a radiation of a wavelength of 400 nm or less, emits fluorescent light having a wavelength over 400 nm, more preferably, over 450 nm.

A translucent subject is a motif formed by dye layers on opposite sides of a substrate layer (e.g., a document or a film applied to a document) and which can be recognized as a whole when the security document is viewed in phantom, otherwise but not (or at least much worse) can be detected. The motif is recognizable as a motif by the human eye (eg because it represents an easily recognizable image) or it can be recognized by a machine (eg because it represents a machine-readable code). Often, but not necessarily, the translucent subject is difficult to discern when the document is viewed in reflection.

A "substrate layer" is a complete substrate of the security document or a layer of such a complete substrate.

Terms such as "down", "down", "down" and "down" refer to an orientation of the document when one of its surfaces faces up and the other down.

The term "paper" includes paper-based wood pulp as well as cotton.

1 shows a bill as an example of a security document. The document comprises a substrate or carrier material 1 , As I said, the substrate can 1 comprise a single substrate layer or multiple substrate layers, in particular of paper or plastic materials. In the sectional view of 2 is the substrate with a single substrate layer 1a shown.

The substrate 1 carries a variety of markers, as generally known, for. B. security features 2 , artistic representations 3 and text information 4 , In addition, the substrate carries 1 a translucent motif 5 ,

The translucent motif 5 comprises at least two dye layers 6a . 6b , As mentioned, the dye layers 6a . 6b magnetic dye layers and / or IR dye layers and / or UV fluorescent dye layers as defined above; that is, each dye layer 6a . 6b may be magnetic or IR absorbing or fluorescent under UV radiation. At least one of the dye layers 6a . 6b can also have at least two of these properties and z. B. both magnetic and IR absorbing to increase safety. In other words, at least one of the dye layers may include at least two members of the group comprising magnetic dye layers, IR dye layers, and UV fluorescent dye layers.

In an advantageous embodiment, only one of the dye layers 6a . 6b visible when the document is viewed in reflection, ie it is irradiated with electromagnetic radiation from one side and viewed (in the spectral range of electromagnetic radiation) from the same side; or if both dye layers are visible, one of them is clearly more recognizable than the other.

In "Transmission or Transmission Inspection", both dye layers become visible. The term "examination in transmission" has different meanings, depending on whether the dye layer pointing away from the viewer (ie from the sensor) is magnetic or IR-absorbing or UV-fluorescent:
When the dye-providing layer facing away from the viewer is a magnetic dye layer, a transmission study is usually a magnetic examination, e.g. B. by measuring the magnetic permeability μ or remanence of the document. For this purpose, z. For example, a measuring coil may be placed on one side of the document and used to measure the magnetic properties resulting from both magnetic color layers.

If the dye-providing layer facing away from the viewer is an infrared-absorbing dye layer, an examination in transmission usually involves irradiating the document on the side facing away from the viewer (sensor) so that the radiation (which is in the infrared spectral range between 770 nm and 10 μm) the document penetrates. Shadows are created by both dye layers (if they are both are infrared absorbing). The radiation wavelength is chosen so that the substrate 1 transmits a substantial portion of the radiation (at least 30%) while the dye layers absorb or reflect a substantial portion of the radiation (at least 30%).

If the dye layer facing away from the viewer is a UV fluorescent dye layer, an examination in transmission comprises irradiating the document on the side facing away from the viewer (sensor) with UV radiation so that fluorescent light is generated. The fluorescent light penetrates the document and combines with the dye layer on the other side to create a translucent motif. The dye layer on the other side can, for. B. also be a UV fluorescent dye layer, in which case the document should be designed such that it passes through at least a portion of the UV radiation.

The two dye layers may be different dye layers, e.g. A UV fluorescent dye layer may be combined with an IR dye layer or a magnetic dye layer, etc.

In the embodiment of 2 includes the substrate 1 a single substrate layer 1a , 3 shows an embodiment with multiple substrate layers 1a . 1b . 1c which are laminated to form a substrate. The different substrate layers 1a . 1b . 1c can be made of the same material or different materials.

In this embodiment, the dye layers 6a . 6b , ..., which form the translucent motif, on the top layer 1a , between the substrate layers 1a . 1b . 1c or under the lowest layer 1c be arranged.

One between the substrate layers 1a . 1b . 1c arranged dye layer, such as the dye layers 6c and 6d in 3 , is physically protected against the environment and against access by a user, improving security and durability. If at least one of the substrate layers 1a . 1b . 1c In the visible spectral range is not transparent, beyond the embedded dye layer is difficult to detect.

At least some or all of the dye layers 1a . 1b . 1c . 1d are separated by at least one substrate layer. In the embodiment of 3 For example, the dye layers 6a and 6b through all three substrate layers 1a . 1b . 1c separated while the dye layers 6a and 6c only through the substrate layer 1a are separated.

In this way, a complex multi-layered structure can be built which is difficult to imitate.

4 shows a sectional view of a security document with a window B. More generally, such a document has a first section 9 (the area around the window 8th around) with low transmission and a second area 8th with high transmission. The terms "low transmission" and "high transmission" are to be understood as a relative relationship, ie the section with low transmission has a lower transmittance (by at least 30%) than the section with high transmission. This transmission is to be measured at a given wavelength, which may be in the visible spectrum or in the infrared spectrum; ie the window 8th For example, an infrared window with increased infrared transmission at at least one wavelength may be between 0.8 and 10 microns, or there may be a visible light window with increased transmission in the visible spectrum, e.g. Between 400 nm and 770 nm.

In an advantageous embodiment, the dye layers 6a . 6b at least partially in the first section 9 arranged, ie in the section with low transmission. This ensures that the dye layer facing away from the viewer (sensor) 6b not clearly visible when reflected.

In a further advantageous embodiment, the dye layers 6a . 6b at least partially in the second section 8th arranged, ie in the high transmission section. This makes it possible to see the dye layers at the given wavelength from both sides, even upon reflection.

The window 8th That is, the high transmission portion may be formed in an otherwise opaque document in various manners known to those skilled in the art, e.g. By applying a nontransparent coating to a transparent substrate layer or by laminating nontransparent and transparent substrate layers having at least one opening in the nontransparent layer. In the example of 4 becomes the window 8th produced by a transparent substrate layer 1b between two nontransparent substrate layers 1a . 1c is embedded, wherein at least partially overlapping openings 13 in the non-transparent substrate layers 1a . 1c are provided.

The translucent motif 5 can be any symbol, as in 1 shown. It can also be a computer-readable code, as in 5 shown, wherein z. For example, a given range 10 of the security document is subdivided into subareas. In each of the subregions, there may be (a) no dye layer 6a . 6b give; (b) give only a first of the dye layers, (c) give only a second of the dye layers; or (d) dye layers 6a . 6b on both sides. This arrangement may, for. For example, encode 4 values per subrange if two dye layers are used.

Other coding schemes may be used, such as bar codes, QR codes, etc.

In yet another embodiment, the translucent element 5 be formed by an alphanumeric string or letters, as in 6 with some parts being formed by a first one of the dye layers and other parts being formed by a second one of the dye layers. It is also possible to form some parts through both dye layers.

As mentioned, the dye layers 6a . 6b magnetic dye layers or infrared dye layers or both. Infrared and magnetic dye layers can also be combined in the same document.

The dye layers 6a . 6b , ... should preferably be aligned, ie their relative position should be precise within certain limits. If the limits are chosen sufficiently narrow, z. B. 500 microns or less, a forgery is particularly difficult because normal printing devices can not print on two sides of a document or a substrate layer with such accuracy. However, security printing devices, particularly devices that print simultaneously on both sides of the substrate or a substrate layer, are capable of achieving such accuracy of registration.

For testing the alignment accuracy, at least one edge of the first dye layer 6a be arranged on the same line as an edge of the second dye layer 6b , as in 1 shown.

The dye layers can be printed by suitable printing techniques, such as offset printing, screen printing or gravure printing. However, the best alignment accuracy can be achieved in offset printing, which is therefore an advantageous method.

The translucent subject can be applied to any part of the document. The dye layers 6a . 6b , ... can be applied in combination with conventional printing layers, as in 2 by a dashed line 11 indicated either below or above the normal print layers.

In an advantageous embodiment, as mentioned above, at least one of the dye layers is applied to a surface of the document which has the same color as the dye layer, so that it becomes difficult to see the dye layer. The color of the area around the dye layer may be either the original color of the substrate layer adjacent to the dye layer or it may be the color of a printed layer applied below the dye layer.

In yet another embodiment, at least a portion of the dye layers 6a . 6b , ... with a non-transparent printed layer 11 be covered, as in 2 represented by dashed lines.

A document of the type described here can be checked by adding the dye layers 6a . 6b , ... are then checked to see if they together form the translucent motif at Transmission. Additional reflection inspection steps can further improve security or, as mentioned above, allow larger amounts of data to be read out.

The different dye layers 6a . 6b , ... may at least partially overlap one another, or they may cover completely separate areas.

The technique described above can be applied to any type of security document such as banknotes, passports, checks, value documents, identity documents, authorization documents, certificates, etc.

While presently preferred embodiments of the invention have been shown and described, it will be understood that the invention is not limited thereto, but otherwise practiced and practiced within the scope of the following claims.

Claims (17)

Security document with at least one substrate layer ( 1a . 1b . 1c ), which is a translucent motif ( 5 ), which is formed by a combination of at least two dye layers ( 6a . 6b . 6c . 6d ) formed on different sides of the substrate layer ( 1a . 1b . 1c ), characterized in that the dye layers are selected from the group comprising: magnetic dye layers, IR dye layers and UV fluorescent dye layers. A security document according to claim 1, wherein the two dye layers ( 6a . 6b . 6c . 6d ) are magnetic dye layers. A security document according to claim 1, wherein the two dye layers ( 6a . 6b . 6c . 6d ) Are infrared dye layers. A security document according to claim 1, wherein one of the dye layers ( 6a . 6b . 6c . 6d ) an infrared dye layer and the other of the dye layers ( 6a . 6b . 6c . 6d ) is a magnetic dye layer. Security document according to one of the preceding claims, wherein at least one of the dye layers ( 6a . 6b . 6c . 6d ) is applied to a surface having the same color as the dye layer, so that the dye layer is imperceptible to the naked eye. Security document according to one of the preceding claims, comprising a plurality of substrate layers ( 1a . 1b . 1c ). A security document according to claim 6, wherein at least one of the dye layers ( 6a . 6b . 6c . 6d ) between two substrate layers ( 1a . 1b . 1c ) is arranged. Security document according to claim 7, wherein both dye layers ( 6a . 6b . 6c . 6d ) between two substrate layers ( 1a . 1b . 1c ) are arranged. Security document according to one of claims 6 or 8, wherein at least one of the dye layers ( 6a . 6b . 6c . 6d ) on an upper side of the uppermost substrate layer ( 1a ) or on an underside of the lowest substrate layer ( 1c ) is arranged. Security document according to one of claims 6 to 9, wherein the translucent motif ( 5 ) by a combination of at least three dye layers ( 6a . 6b . 6c . 6d ), wherein at least some of the dye layers ( 6a . 6b . 6c . 6d ) by at least one substrate layer ( 1a . 1b . 1c ) are separated. Security document according to one of the preceding claims, wherein the substrate layer or layers ( 1a . 1b . 1c ) Paper layers and / or plastic layers is / are. Security document according to one of the preceding claims, with a first section ( 9 ) with low transmission at a given wavelength and a second section ( 8th ) with high transmission at a given wavelength, the dye layers ( 6a . 6b . 6c . 6d ) at least partially in the first section ( 9 ) are arranged. Security document according to one of the preceding claims, with a first section ( 9 ) with low transmission at a given wavelength and a second section ( 8th ) with high transmission at a given wavelength, the dye layers ( 6a . 6b . 6c . 6d ) at least partially in the second section ( 8th ) are arranged. A security document according to any one of claims 12 or 13, wherein the given wavelength is between 0.8 μm and 10 μm. A security document according to any one of claims 12 or 13, wherein the given wavelength is between 400 nm and 770 nm. Security document according to one of the preceding claims, wherein at least one of the dye layers ( 6a . 6b . 6c . 6d ) belongs to at least two elements of the group consisting of: magnetic dye layers, IR dye layers and UV fluorescence dye layers. A security document according to any one of the preceding claims wherein the first dye layer and the second dye layer overlap at least partially.

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