DE7634293U1 - FLAT RECORDERING MEDIA - Google Patents

Description

Patent attorneys *:
Dipl. Ing. H: .ins-Jürgon Müller *
Dr. rer. nat. Thomas Bcrendt

08 Munich 80 Lucile-Grahn-Strasse 38

^{LGZ LANDIS & GYR ZUG AG} CH-6301 2UG Switzerland

document

The innovation relates to a document with a flat Carrier body on which authenticity information is embossed in the form optical markings with a light-modifying Relief structure are stored.

Documents such as banknotes, securities, identity cards, authorization cards, Tickets and the like have become an indispensable tool in daily life. The money or The legal value of such documents is often considerable, which incites criminal elements of society to do so to falsify, modify or copy.

More and more machines are being used in industrialized countries used to check the authenticity or identity of the documents Examples are bank note validators and bank note changers and acceptance devices for tickets or tickets mentioned. If the authenticity or identity features are more suitable for machines Documents are designed too simply, this in turn represents a strong incentive for fraudulent activities.

One of the safest known methods of opposing a document Securing counterfeiting consists in relying on this authenticity

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information in the form of a diffraction grating or hologram save. Such diffraction gratings and holograms can be relatively easily machine read and authenticated; their production, on the other hand, requires difficult to access, Costly technical aids and in-depth specialist knowledge, so that promising counterfeits at best possible with an extremely high level of effort are .

It is known for the mass production of holograms embossed with an embossing die in a carrier made of thermoplastic material. The application of this duplication method was already used for the production of card-shaped Means of payment proposed, with holograms or diffraction gratings be embossed into a carrier body made of plastic.

Furthermore, an identity card is known which is protected against counterfeiting in that it is placed in a carrier body made of plastic a refractive profile is punched.

So far, however, it has not been possible to use the embossing technique for duplication of holograms or diffraction gratings on substrates made of paper, cardboard or similar materials. The invention is therefore based on the object of creating a document of the type mentioned at the outset, which under Application of the known embossing technology can be produced, although its carrier body consists of a material that because of its fiber, grain or cell structure or because of its thermal properties for the application of the embossing technique is unsuitable in itself.

The innovation is that it is made of non-thermoplastic Material of the existing carrier body is at least partially coated with a thin thermoplastic layer, in which the optical markings are embossed.

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Some exemplary embodiments of the innovation are described below explained in more detail with reference to the drawings.

1 shows a document in plan view,

Fig. 2 greatly enlarged sectional views

and 3. _,,

of a document,

Fig. 4 greatly enlarged excerpts from embossing

and 5 stamp and

6 shows another document.

In Fig. 1, 1 denotes the flat support body of a Document, which is preferably a banknote or a security, an identity card or an authorization card (admission ticket, Ticket, etc.) is. The carrier body 1 consists of a non-thermoplastic material, preferably paper or cardboard, which due to its surface texture or its thermal properties is unsuitable in itself, through an embossing process information in the form of a very fine light-modifying friction structure.

The carrier body 1 is at least partially with a thermoplastic Layer 2 coated. In the example of FIG. 1, this layer consists of thermoplastic printing ink which is on the carrier body 1 is printed and represents numeric or alphanumeric characters. By applying sufficient paint it is ensured that the thermoplastic printing ink from the surface of the carrier body 1 is not completely is absorbed, so that after the printing ink dries, a smooth layer surface is created in the printed areas, which is the fiber, grain or cell structure of the carrier body 1 covered. The thermoplastic printing ink has such a temperature characteristic that the layer 2 can be plastically deformed using pressure and heat without the carrier body 1 of the document damaged. The remaining areas of the document left open in FIG. 1 can be carried out in a conventional manner and Way with characters, ornaments, pictorial representations and the like. Be printed.

PA 1898

Optical markings with a light-modifying relief structure are embossed into the thermoplastic layer 2. This relief structure is designed in such a way that when Reading out the authenticity information represented by the friction structure in an optical reading device is a modification of the beam path of the reading light beam.

In Fig. 2, the carrier body 1 and the thermoplastic Layer 2 can be seen in section. The optical markings 3 embossed in the layer 2 represent a light diffraction element here which has microscopic fine details and light thrown onto the relief structure due to the laws modified by light diffraction. It is easily possible to emboss optical markings 3, the details of which are shown in are of the same order of magnitude as the wavelength of the visible light. The light diffraction element can preferably be a simple phase diffraction grating with a characteristic Periodicity and characteristic line profile; advantageous A hologram is also suitable, which converts incident radiation with a given wavelength into one or more predetermined Directs directions.

The authenticity information contained in the light diffraction element can be read in suitable reading devices with the help of light sources and light sensors. Such readers are known and are therefore not described in more detail here. Preferably the authenticity information is read out based on the radiation reflected by the optical markings 3. If the carrier body 1 causes a low scattering and absorption of the incident radiation, it is also possible query the transmitted radiation.

The presence of optical markings 3 on a document can also be easily checked visually. In particular in the case of a light diffraction element with a diffraction grating structure the authenticity of the document can be determined based on the color spectrum in which daylight or white light falls

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Artificial light is broken down without any aids will,

The optical markings 3 representing a light diffraction element have a typical line spacing d of approximately 2 Micron on; but it is also a smaller or larger one Line spacing in the range of 0.5 to 10 microns possible. The typical profile depth χ of the relief structure is less than 1 Microns and the typical layer thickness h of the thermoplastic Layer 2 is a multiple of x.

In addition to such fine structures, it is also possible to use the thermoplastic layer 2 to emboss optical markings with a coarser relief structure, the incident light essentially not by diffraction, but by reflection or optical refraction due to the laws of geometrical optics modified. An optical marking of this type embossed in the layer 2 is denoted by 4 in FIG. 3, wherein It should be noted that FIG. 3 is not drawn to scale in relation to FIG. 2. The line spacing d is here 10 to 1OO micronr The markings 4 are in the Example of FIG. 3 shows a facet profile with a sawtooth-shaped Cross-section that reflects incident light in a defined manner.

Markings 3 or 4 are embossed using pressure and heat with an embossing die. Fig. 4 shows a section of an embossing die 5 made of metal, into which a master diffraction grating or for pressing the markings 3 a master hologram is incorporated by etching or the like. A section from an embossing die 6, which is suitable for embossing the markings 4, can be seen from FIG. 5. The embossing dies 5, 6 can be designed as a stamp or as an endless embossing belt.

If the embossing die 5 or 6 also covers areas of the document that are not coated with the thermoplastic layer 2

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are true, these areas may also be deformed. In contrast to coated areas, however, the uncoated embossed areas cause considerable scatter of the incident radiation without modifying it in a characteristic way.

The storage of authenticity information in the form of embossed Optical markings in the thermoplastic layer 2 can be used for this purpose, printed numeric or alphanumeric To make characters machine-readable when different characters have different relief structures or different orientations are assigned to a structural structure will. In other words, this means that on the carrier body 1 information in numerical or alphanumerical form Form are printed and that the same information in coded form in the embossed markings.>, 4 included are. This allows, for example, the name of a person or an account number in the reader in a simple manner from the printed Read out document.

In Fig. 6, 7 denotes the supporting body of a conventionally printed document. Printed and / or unprinted Areas of the carrier body 7 are subsequently coated with a thermoplastic, transparent layer 8, which in the example shown has the shape of a narrow band similar to the security thread of a bank note. the Layer 8 can also cover the entire surface of the document. You can use known printing or coating methods be applied to the printed carrier body 7. In the thermoplastic layer 8 are in turn optical Markings 3 or 4 (Fig. 2 and 3) embossed with a light-modifying Re flow structure.

Coded information can also be included in the document be entered that the optical markings 3, 4 only in selected areas of the thermoplastic layer 2 or 8, the location of the markings on the document representing the information.

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To the embossed in the thermoplastic layer 2 or 8 optical markings 3, 4 against mechanical wear, To slit sweat and the like, this is preferably covered with a transparent protective layer. So that the diffraction effect the fine relief structures are preserved, a protective layer can be buried, the other Has refractive index than the thermoplastic layer 2 or 8, Furthermore, a thin layer can be placed between the two layers

metallic reflective layer can be inserted. Such

Reflective layer can be produced chemically or by vapor deposition

■ | and have a thickness of a few hundred angstroms.

j Finally, it is also possible to use a

simple transparent wrapping against damage to the markings 3, 4 to protect.

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Claims (8)

Today's Sohutz claims 1 - 10 1. Flat document with light-modifying, optical Authenticity information corresponding markings, in which a non-thermoplastic carrier with a thermoplastic layer having optical markings is coated, characterized in that that the carrier body (1; 7) at least partially with a thin thermoplastic layer (2; 8) is coated, in which the optical markings (3; 4) are embossed. 2. Document according to claim 1, characterized in that the carrier body (1; 7) consists of paper or cardboard. 3. Document according to claim 1 or 2, characterized in that the optical markings (3) are of the type that they are due to the light cast on their relief structure modify the laws of light diffraction. 4. Document according to claim 3, characterized in that the optical markings (3) have a line spacing of 0.5 to 10 microns. 5. Document according to one of Claims 1 to 4, characterized in that that the optical markings (4) are of such a type that they are thrown onto their relief structure Modify light through reflection or optical refraction based on the laws of geometrical optics. 7634293 08/05/77 OT P , 6. Document n, soh one of claims 1 to 5, characterized characterized in that the carrier body (1) is printed with thermoplastic ink (2) and that the markings (3; 4) are embossed into the color scheme. 7. Document according to one of claims 1 to 6, characterized characterized in that the thermoplastic layer (8) ■■ is transparent and on printed and / or unprinted I th areas of the support body (7) is arranged. f 8. Document according to one of claims 1 to 7, characterized in that I indicates that the markings (3; 4) are machine-readable i are. < ^s 9 · Document according to Claim 8, characterized in that ; the machine-readable markings (3; 4) numeric or ii are alphanumeric print characters (12). 10. Document according to one of claims 1 to 9, characterized in that that the machine-readable markings (3; 4) Form at least one phase diffraction grating or hologram. 7634293 9105.77