EP1322478B1 - Method and device for personalising luminescent marks of authenticity - Google Patents

Abstract

A method and device for personalizing the luminescent authenticity features on data carrier, in particular plastic cards. The luminescent authenticity feature being applied to or incorporated in a composite card and the authenticity feature is personalized with a high-energy beam in that the intensity and/or wavelength of the beam is chosen such that local bleaching of the structure of the authenticity feature takes place.

Description

In the prior art, it is possible to produce black markings with laser marking systems. This is used in laser personalization, which is used as a high-quality economic process in many areas and is often a security feature.

Furthermore, so-called "UV inks" are used in security features. These "UV colors" are only visible when excited by UV light for fluorescence or phosphorescence. They are available in printing inks or in fibers and are processed by various printing processes or added directly to the substrates paper or plastic.

A problem arises from the fact that in safety technology the so-called "UV colors" are used, which are only visible under UV light due to fluorescence or phosphorescence, but that security features developed from them can not be personalized. Rather, these features are z. B. in the case of securities or plastic cards as a print or as an additive (fibers) in paper or plastic.

The US 3,507,655 A discloses a data carrier in the form of an identity card, in which the authenticity feature is heat-changeable and is partially extinguished by the action of heat. There, the authenticity feature is partially changed by thermal fading of the heat-sensitive ink. There is no luminescent authenticity feature, and no negative image of an authenticity feature is generated.

With the subject of US 3,507,655 A a plastic container has become known, wherein a plastic substrate is proposed for attachment to the walls of a container, in which a serial number is written by fading. The writing of a serial number by bleaching however, the color is merely a primary authentication feature because only partial fading occurs. However, there can be no review of controlled bleaching. Consequently, there is no personalization of this registered serial number by a subsequent processing.

The invention is therefore based on the US 4,663,518 the task is to create a personalization with higher reliability and the possibility of later reviewing this personalization.

To solve the problem, the invention is characterized by the technical teaching of claim 1.

Accordingly, in the invention, a negative image of the personalized authenticity feature is inscribed in the non-personalized authenticity feature, which is designed to be luminescent. In other words, the personalized authenticity feature does not light up when excited.

The invention thus sets a laser personalization of UV security features z. B. in plastic cards and combines the advantages of two methods, namely a personalization by laser beam and beyond the personalization of luminescent substances and their verification under UV light or other high-energy excitation medium.

The invention generally claims the personalization of luminescent authentication marks, of whatever kind, on any data carriers. Furthermore, the personalization of chemo- and / or bioluminescent substances is generally claimed as essential to the invention. It is therefore used in the following description of the generic term "luminescence" as a synonym for all three luminous phenomena.

In a preferred embodiment of the invention, a multi-layered plastic card (eg in the form of a check card) is described as a data carrier. However, the invention is not limited thereto. Merely for reasons of simplification, the construction of a check card for the further description of the invention will be referred to in the following.

Likewise, all possible integrations and installation locations of the luminescent marking in a data carrier are claimed. The marking can therefore be printed on a certain or even several layers of the data carrier or applied in other ways as an ink. However, the marking can also be incorporated in the plastic polymer of one or more layers of the data carrier. The luminescent substance may also be incorporated in the adhesive, the paint or as an additive in the plastic material.

For the purpose of further simplification, the term "UV color" generally means a label, substance or authenticity feature which, by utilizing photo and / or chemo and / or bioluminescence upon absorption of a high-energy light (usually ultraviolet light), produces a luminous appearance caused. Although it is preferred within the scope of the invention that the luminous phenomenon occurs in visible light. However, the invention is not limited thereto. For a machine authenticity recognition of check cards, therefore, this luminous appearance can also occur in the non-visible spectral range and be evaluated by machine. Likewise, the invention is not limited to excitation with UV light; It is therefore also possible to provide an excitation in a corresponding electromagnetic field, which is suitable for bringing the substance to light (visible or non-visible).

Among the various interactions between laser light and matter is the bleaching of color-active substances. According to the invention, it is possible with the aid of a laser beam to destroy these color-active substances. For example, the body color of a substrate containing pigments changes from colored to white.

This process is used in the context of the present invention.

A basic prerequisite for this process is that the color-active substance absorbs the laser light and enters into a chemical reaction in which it loses its color properties. In the simplest case, a chemical degradation of the color-active substance takes place. In addition, the laser light should not excite any side reactions that lead to a discoloration of the substrate, and thus cause no bleaching to white.

The principle of bleaching with laser light can now according to the invention also be transferred to so-called "UV colors". These "UV inks" contain pigments or dyes which normally do not appear colored or are only slightly colored, but are excited by UV absorption or other electromagnetic excitation to emit visible light.

The phenomenon is commonly referred to as "cold glow" or luminescence. Depending on the lifetime of the excited states, a distinction is made between fluorescence and phosphorescence, in the first case the emission being very fast, in the second case afterglow even after UV excitation.

The term "UV inks" is commonly used but is misleading in that most of the so-called substances are not colored. In addition, the term "UV inks" is used inaccurately for UV-curable inks. Here, the term UV does not refer to luminescent effects, but to the mechanism of chemical curing during processing.

In the bleaching of "UV inks" according to the invention, the color-active substance is destroyed by intense laser light, analogously to the absorption colors. However, the substrate should not be damaged in the visible range or changed in their color impression. It must therefore be a selective (UV) wavelength range (band, in the non-visible range) are selected and the intensity must be metered so that the UV color itself by the absorption is excited and then disintegrates, which corresponds to a bleaching. In this way one would do the bleaching with visible pigments.

Since "UV inks" are not or only slightly colored under normal conditions, they barely absorb any visible light. Therefore, ultraviolet light must be used for bleaching. In this case, it is preferable to select a laser wavelength range which is absorbed particularly well by the "UV color" used.

• Zinnsulfidderivate,
• Benzoxazinonderivate,
• Pyrazolinderivate

"UV inks" which are suitable for bleaching by UV laser radiation belong, for example, to the following substance classes:

• Zinnsulfidderivate,
• Benzoxazinonderivate,
• pyrazoline

For bleaching the "UV inks" it is possible to use not only ultraviolet but also infrared radiation and / or radiation of other wavelengths if the color-active substances in the corresponding spectral range absorb the particular radiation used without there being any visible discoloration of the color-active substances.

In a simple embodiment of the invention, the substrate to be marked has a uniform luminescence. This is achieved by a uniform application of "UV inks" or by incorporation of the "UV inks" into a polymeric matrix. The substrate can then be marked by the laser by bleaching the "UV color" locally completely. In this way, for example, vector fonts or raster-scanning images can be generated. Furthermore, it is possible to achieve a partial bleaching by modulation of the laser power and thus to generate grayscale images.

In the following the invention will be explained in more detail with reference to drawings showing only one embodiment. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Fig.1:

Schnitt durch einen vereinfacht dargestellten Kartenaufbau im Ausgangszustand des Verfahrens;

Fig.2:

Schnitt durch den Kartenaufbau nach Fig. 1 mit Einwirkung eines Laserstrahls;

Fig. 3:

schematisiert eine Draufsicht auf den Aufbau nach Figur 2;

Fig. 4:

den Kartenaufbau nach Fig. 2 und 3 bei Anregung mit energiereichem Licht;

Fig. 5:

die Draufsicht auf den Kartenaufbau nach Figur 4.

Show it:

Fig.1:

Section through a simplified illustrated map structure in the initial state of the process;

Figure 2:

Cut through the map structure after Fig. 1 with the action of a laser beam;

3:

schematizes a plan view of the structure FIG. 2 ;

4:

the map structure after FIGS. 2 and 3 when excited with high-energy light;

Fig. 5:

the top view of the map structure after FIG. 4 ,

In FIG. 1 is a section of a map structure shown in section to an unqualified size. On a carrier film 2 in this case a luminescent authenticity feature 3 is arranged. When lighting with, for example, UV light 5, the structure 4 is excited in such a way that, for example, in the visible light 6 is a lighting up.

According to the invention, this authenticity feature 3 is to be personalized. For this purpose, with a laser beam 7 (see FIGS. 2 and 3 ), for example Lettering 8 inscribed in the structure 4 of the authenticity feature 3. The intensity of the laser beam is chosen so that the structure 4 is converted into the structure 4 'only in the region of the action of the laser beam. In this case, the structure 4 'should have no visible in the visible light structure or color change.

Only in the case of irradiation with UV light 5 should the structure 4 '(see FIG. 5 ) no longer or only very slightly luminescent light up, but it should be a different colored light 9 or even a negative image in the illuminating overall picture. The inscribed lettering 8 does not light up or only partially or differently colored than the surrounding area.

If the luminescence chosen by selecting the intensity of the laser beam 7 so that it only leads to an impairment of luminescence, but not to extinction, even when irradiated with a UV lamp 10, a halftone or gray scale image can be seen as lettering 8 ,

Of course, the embodiment explained here is not restrictive to the scope of protection. There are all variants and modifications described in the general description part. For example, it requires no irradiation with a UV lamp 10 to bring the authenticity feature 3 to light up. It is also sufficient to excite with radiation of other wavelengths in the non-visible spectral range and / or in the alternating electromagnetic field.

drawing Legend

1

cover sheet

2

support film

3

authenticity feature

4

structure

4 '

changed structure

5

UV light

6

radiated light

7

laser beam

8th

Lettering (personalization)

9

radiated light

10

UV lamp

Claims (8)

1. Data carrier of any kind, especially composite cards, wherein authenticity features (3) being applied or incorporated in or on the composite card (1,2) which can be personalized with a high-energy beam, e.g. a laser beam (7) or an electron or neutron beam, wherein intensity and/or wavelength of the beam are chosen to enable local bleaching of structures (4,4') of the authenticity feature (3), within which the bleaching destroys at least partly a chromophoric substance of the authenticity feature (3) which can be personalized, and wherein the authenticity features (3) which can be personalized are luminescent and wherein the destruction of the chromophoric substance of the authenticity features (3) which are luminescent and personalized cannot be detected in visible light, characterized in that the personalized luminescent authenticity features (3) are not luminescent with the authenticity features (3) which are not personalized and in such a negative image appears in the overall luminescent image or that a negative luminescent image is visible.
2. Data carrier according to claim 1, characterized in that partly bleaching of the structure (4') of the authenticity feature (3) is achieved through modulation of the energy of a laser beam (7)
3. Data carrier according to one of claims 1 or 2, characterized in that the personalized authenticity feature (3) can be lighted up through use of an electromagnetic field.
4. Data carrier according to one of claims 1 to 3, characterized in that the lighting up of the authenticity feature (3) can be achieved by photoluminescence and/or chemiluminescence and/or bioluminescence.
5. Data carrier according to one of claims 1 to 4, characterized in that the lighting up can be achieved in the visible and/or invisible spectral range.
6. Data carrier according to claims 1 to 5, characterized in that the excitation of the authenticity feature (3) can be achieved by UV-light (5) and/or IR-radiation.
7. Data carrier according to one of claim 1 to 6, characterized in that the color active substance of the authenticity feature (3) which can be personalized belongs to the classes of derivatives of stannic sulfides, derivatives of benzoxazinone or derivatives of pyrazoline.
8. Data carrier according to one of claim 1 to 7, characterized in that the personalized authenticity features (3) are phosphorescent and in that, after the personalization, a negative phosphorescence image becomes visible upon excitation.

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