EP1384594B1 - Protection against data tampering - Google Patents

Abstract

Means for protecting a printed document from data falsification comprises a relief pattern in a zone bearing the data, the relief being exclusively due to the thickness of the ink used to form the pattern. An Independent claim is also included for protecting a printed document from data falsification by printing a substrate with the data, printing a design with a thick layer of ink containing an activatable polymerizable material, and activating polymerization by supplying energy.

Description

The invention relates to devices and methods for preventing the falsification of statements affixed either by printing or manually to a printed document.

The type of falsification targeted by the device of the invention is specifically the alteration of initial data, which are replaced by others, which serve the purposes of the fraudster.

These data can be either "fixed" data, which are identical on all the documents of a series (facial value of a voucher), or data specific to a specific document; in this case they are referred to generically as "variable data" and can typically be a signature, serial number, code, etc.

The documents covered by the present protection system are, in particular, authentic or authenticated documents, checks, traveler's checks, certificates, identity documents, lottery tickets, titles, etc. The substrate on which these documents are printed will therefore go from normal paper to plastic card, through special paper, watermark, etc.

Using a traditional forgery technique, fraudsters start from a worthless document (or of lesser value) and alter by scrubbing or scraping some initial data that interferes with them (nominal value of a check, lottery number, name of beneficiary, etc.) to replace them with others.

To complicate the task of these fraudsters, different methods are applied, such as the use of alterable surface or the printing of an underlying pattern: the alteration of the initial data also alters the underlying pattern, which must be redrawn or completed.

EP 0 184 529 describes the use of an ink absorbing substrate used by the variable data.

Another method consists in giving a relief to the surface of the substrate in particular by the process of soft-cutting (intaglio), which forces the fraudsters to further alter the surface of the substrate.

It goes without saying that these different processes can, in addition, be combined with each other, making the task of fraudsters all the more difficult.

The effectiveness of these different processes is, however, defeated by the increasingly tortuous methods applied by fraudsters, hence the need for an apparatus sometimes very sophisticated to detect fraud.

An object of the invention is that an attempt at fraud is easily detectable, even to a little exercised.

Another object of the invention is the development of a relatively inexpensive method, which can be easily extended to many types of documents.

The object of the invention is a device for protecting against falsification of data carried on a printed document in which, at least in a zone intended to affix the variable data, the document comprises at least one raised pattern, obtained by one of the following methods: screen printing, flexography, rotogravure. This relief is due exclusively to the thickness of the ink layer used to form this pattern. The embossed pattern is affixed either above or below the data to be protected.

The ink used preferably contains optical effect pigments; the optical effect is advantageously an iridescence or an opalescence.

1. a) sélectionner un substrat
2. b) imprimer sur ce substrat une donnée à protéger
3. c) sélectionner une encre contenant un matériau polymérisable et un accélérateur de polymérisation
4. d) sélectionner un procédé d'impression parmi les procédés suivants : la sérigraphie, la flexographie, l'héliogravure
5. e) imprimer un motif avec cette encre à l'aide de ce procédé
6. f) activer l'accélérateur de polymérisation par un apport énergétique ad hoc
7. g) faire polymériser l'encre en couche épaisse

Another object of the invention is a method for protecting against falsification of data on a printed document which comprises the following operations:

1. a) select a substrate
2. b) print on this substrate a piece of data to protect
3. c) selecting an ink containing a polymerizable material and a polymerization accelerator
4. d) select a printing process among the following methods: screen printing, flexography, rotogravure
5. e) print a pattern with this ink using this process
6. f) activate the polymerization accelerator with an ad hoc energy supply
7. g) polymerize the ink in a thick layer

In this method, the operation b can be performed after the operation g, the sequence being as follows: a, c, d, e, f, g, b

The printing process is preferably selected from the following methods: screen printing, flexography, gravure printing.

Advantageously, the polymerization is activated by an energy supply by electromagnetic radiation, selected from the following: infrared, UV, microwave.

• La Fig. 1 est une vue schématique en perspective avec dimensions exagérées montrant la falsification par grattage d'un document à substrat plat.
• La Fig. 2 est une vue schématique en perspective montrant la falsification par grattage d'un document à substrat embossé.
• La Fig. 3 est une vue schématique en perspective du résultat d'une tentative de falsification du dispositif de l'invention.
• La Fig.4 est une vue schématique similaire à la Fig.3 avec apposition ultérieure de la donnée à protéger.

Other features and advantages of the invention will emerge from the following description of modes of particular embodiment of the invention, reference being made to the appended drawings in which:

• Fig. 1 is a schematic perspective view with exaggerated dimensions showing the forgery forgery of a flat substrate document.
• Fig. 2 is a schematic perspective view showing the forgery forgery of an embossed substrate document.
• Fig. 3 is a schematic perspective view of the result of an attempt to falsify the device of the invention.
• Fig.4 is a schematic view similar to Fig.3 with subsequent affixing the data to be protected.

Fig. 1 shows the effect of scratching in the case of a conventional printed document on flat substrate 8.

The scraping by any sharp object 2 of a datum to be protected, a "variable datum" 4 (here a letter A) also alters an underlying printed pattern 6, leaving a "white zone" that the fraudster is obliged to maintain. make up to conceal the falsification.

Fig. 2 shows the effect of scraping in the case of an embossed substrate 9: the fraudster is brought, during scraping, to penetrate the surface of the embossed substrate 9.

Such alteration is normally easily identified by transparency. However, some particularly skilled criminals manage to minimize this characteristic.

Fig. 3 shows the result of an attempt to falsify a document protected by the device of the invention.

In this device, where the shape of the substrate 8 is of little importance, a pattern 10 is superimposed on the data at 4. This pattern 10 appears in relief because it is formed of an ink deposited in a thick layer 12.

Accordingly, the data to be protected 4 is closely related to the reason 10 and it is impossible to proceed with selective scraping. Any attempt to falsify automatically causes a three-dimensional destruction of the pattern 10. It is impossible for the fraudster, even if he had an ink comprising pigments reproducing a color comparable to that of the ink used (which is not already not so easy), to restore the effect given by the relief of the ink layer 12 of the device of the invention.

In order to obtain the particular relief 12 of the device of the invention, an ink containing, in addition to the pigments and a certain quantity of solvents, polymerizable materials ("varnishes", monomers), which is deposited on the appropriate substrate in using a printing process for the transfer of a thick ink layer and the use of large pigments.

These methods include, typically, screen printing, flexography and gravure printing.

The current practice in printing is that, in order to obtain the maximum optical effect of the pigments dispersed in the ink, the ink layer is as thin as possible, and therefore practically two-dimensional. A thin layer also has the advantage of making scraping more difficult.

This result is generally obtained by conventional drying.

Quite the opposite of this practice, in the process of the invention, a brief drying is carried out with intense energy supply, so as to obtain a polymerization almost instantaneous of the ink layer, virtually without volume reduction. As a result, a layer 12 with three-dimensional extension (of the order of ten μm) is obtained. This energy supply can be achieved by raising the temperature, electromagnetic radiation or electron beam.

As we have seen above, in an almost paradoxical way, the scraping of the data 4 is not facilitated, on the contrary: the alterations 14 become only more apparent.

Furthermore, to avoid altering the readability of the data 4 to be protected, the use of a dark and opaque pattern is avoided: it is preferable to use a delicate pattern such as a guilloche pattern (typically width of the order of 0.1 to 0.2 mm, equally spaced), more difficult to reproduce, and made with transparent or translucent inks, for example loaded with pigments producing a particular optical effect when they are are viewed from a certain angle, such as iridescence or opalescence.

In the example of FIG. 3, the apposition of the ink layer has been performed over the data item to be protected 4, the own apposition of which is included in the printing process of the substrate 8.

It will be noted that the data to be protected 4 may itself be a piece of data authenticating the document, such as a holographic image, whose mere presence (even if impaired) may be sufficient for an observer who is not very attentive to concluding that a document is authentic.

The same technique can also be used to protect variable data 4 affixed a posteriori on the relief ink layer 12, as shown in FIG. 4. The most typical case is that of a data item written by hand (signature, etc.).

In this case, the reliefs formed by the thick layer 12 are crushed locally at the time of handwriting. The deletion, as careful as it is, of the data to be protected 4 can not hide the presence of "damaged" reliefs 16, which makes it possible to easily locate a falsified document.

Claims (8)

1. Device for protecting against the falsification of data on a printed document, comprising a document, a printed feature and a feature in relief, characterized in that, at least in an area intended for affixing data to be protected, the document comprises at least one feature in relief obtained by one of the following processes: screen printing, flexography, gravure printing, this relief being due exclusively to the thickness of the ink layer used to form this feature, the feature in relief being affixed either above or below the data to be protected.
2. Protection device according to Claim 1, characterized in that the ink used contains pigments having an optical effect.
3. Protection device according to Claim 2, characterized in that the optical effect is an iridescent effect.
4. Protection device according to Claim 2, characterized in that the optical effect is an opalescent effect.
5. Method for protecting against the falsification of data on a printed document, characterized in that it comprises the following operations:

   a) a substrate is selected;

   b) data to be protected is printed on this substrate;

   c) an ink containing an activatable curable material is selected;

   d) a printing process is selected from the following processes: screen printing, flexography, gravure printing;

   e) a feature is printed with this ink using the above process;

   f) the curing is activated by an influx of energy for the purpose; and

   g) the ink is cured as a thick layer.
6. Method for protecting against the falsification of data on a printed document, characterized in that it comprises the following operations:

   a) a substrate is selected;

   b) an ink containing an activatable curable material is selected;

   c) a printing process is selected from the following processes: screen printing, flexography, gravure printing;

   d) a feature is printed with this ink using the above process;

   e) the curing is activated by an influx of energy for the purpose;

   f) the ink is cured as a thick layer; and

   g) data to be protected is printed on this substrate.
7. Method according to either of Claims 5 and 6, characterized in that the curable material contains a cure accelerator.
8. Method according to any one of Claims 5 to 7, characterized in that the curing is activated by an influx of energy selected from the following means: infra red, UV, microwaves.

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