WO2012130907A1

WO2012130907A1 - Security element for a value document, manufacturing method, and corresponding document

Info

Publication number: WO2012130907A1
Application number: PCT/EP2012/055565
Authority: WO
Inventors: Xavier Borde; Julien Gillot
Original assignee: Oberthur Fiduciaire Sas
Priority date: 2011-03-30
Filing date: 2012-03-28
Publication date: 2012-10-04
Also published as: RU2013148138A; AU2012234225B2; PL2691573T3; FR2973398B1; BR112013024902A2; BR112013024902B1; FR2973398A1; CA2828398A1; AU2012234225A1; CN102729673A; EP2691573A1; KR20140026446A; CA2828398C; CN102729673B; RU2586130C2; EP2691573B1; KR101899528B1

Abstract

The present invention relates, in particular, to a security element (12) for a value document (1), which consists of an initially planar substrate (G), including an array (14) of raised lines (16), each raised line (16) comprising a profile (F), said profile (F) comprising gradual variations in the shape thereof along a predetermined line (16) or from one line to the other, said array (16) being colored, characterized in that said colored network (16) consists of repeating contiguous strips (3) formed by adjacent or contiguous threads (120, 121, 122) of at least two different colors (B, R, Y), said strips (3) being overall oriented in the same direction as that of said lines (16) of said array (14).

Description

SECURITY ELEMENT FOR VALUE DOCUMENT, MANUFACTURING METHOD, AND CORRESPONDING DOCUMENT

The present invention relates to a security element for a document-value. E l also relates to a method of manufacturing such a security element, as well as a document-value that includes at least one such element.

The present invention applies more particularly to a security element for a document-value such as, for example, a fiduciary document or similar.

The term "fiduciary document" is understood to mean all documents such as bank notes, checks, bank cards or other means used to transmit a sum of money.

The term "assimilated document" is understood to mean all documents issued by a State administration to prove the identity of a person, or of his rights to drive a vehicle, such as an identity card. , a passport or a driver's license.

This expression also refers to any type of document used to authenticate an object of value, such as, for example, a label to put on a garment. We also hear any document used to authenticate the payment of a tax, such as tax stamps.

In such a field, and more particularly for banknotes, it is known to affix one or more security elements of various natures to protect these documents from possible counterfeiting.

Thus, there are different types of security element, and more particularly those called "first level".

Such a security element is by nature difficult to achieve, while being easily identifiable by the public during a simple observation.

This security element often has a relatively complex graphic design, such as line printing, guilloche, numismatic background, and so on. He employs various printing techniques, such as offset, screen printing, intaglio, flexography, typography, and so on. Of particular interest in the context of the present invention to a security element giving a moiré effect.

In general, moiré is a visual phenomenon of interference resulting, for example, from the superimposition of two non-parallel line networks.

Thus, in the field of banknotes, there are some that have a security element formed of parallel lines in relief, and a network of parallel lines in color, oriented differently from the raised lines.

Depending on the angle of observation, some effects of colors, iridescence occur through this phenomenon of moiré.

The prior art in the art can be illustrated by the documents US 4,033,059, EP 1,580,020, EP 1 829 709 and EP 1 393 925.

The present Applicant has found that it is possible to obtain a particularly spectacular moiré effect without necessarily having to use non-parallel networks.

Thus, a first object of the invention relates to a security element for a document-value which consists of an initially plane support, comprising a network of lines in relief, each raised line comprising a profile, said profile comprising gradual variations in shape along a given line or from one line to another, said grating being colored, characterized in that said colored grating consists of a repetition of contiguous strips, formed of threads of at least two different colors, adjacent or contiguous, these bands having the same direction as said lines of said network.

By "the same direction" is meant the fact that the strips extend parallel to the lines of the network, without however excluding the situation in which a fraction of these bands extends in a different direction.

This invention is based on the teachings of French Patent No. 2,942,881.

Thanks to the invention, an amplified optical effect is produced compared to that described above, and this to the naked eye. This is a first level security.

However, a microscopic observation of this element of safety reveals a different structure, more difficult to reproduce by counterfeiters, because of the complexity of the relief produced.

Thus, the invention makes false notes detectable using a microscope.

So we are dealing with second-level security.

According to other advantageous and non-limiting features of this security element:

at an angle of observation perpendicular to said plane, the width of said nets is such that said at least two colors can not be clearly distinguished from each other with the naked eye;

said shape variation is periodic, such as a variation in height of the profile;

said profiles comprise at least one sidewall each defining an angle of inclination with respect to a direction normal to the network, said shape variation comprising a variation of the inclination angle of the sidewall of at least one ligand or at least one of them, lines of the grating, gradually along this line, respectively from one line to another, so as to form in light reflection, a gradient optical effect changing according to an observation angle of the element of security ;

said profiles have a generally triangular shape, two adjacent profiles each having a peak, separated by a groove and said variation in shape consists of a variation of the position of the peak of said profiles between two adjacent grooves or a variation of the height of the Crest ;

said grooves are parallel to said bands;

the width of said strips is substantially equal to that of the raised lines;

the width of the bands is preferably between 50 and 2000 μm, advantageously between 200 and 600 μm, even more preferentially of the order of 400 μm; the colored threads forming said strip are of the same width;

said strips have, on at least a portion of their extent, a different orientation, so as to constitute at least one numismatic image;

a generally flat support of said colored strips is coated and deformed using a soft-printing plate, by the dry stamping technique, which has a network of engraved lines, of a shape complementary to that a line of said network.

A second object of the invention relates to a method of manufacturing a security element as described above.

Finally, the invention also relates to a document-value which comprises at least one element as described above.

Preferably, the security element is integrated therein or is reported there.

Advantageously, this document-value is paper, fibrous material, plastic or a combination of at least two of these materials.

Other features and advantages of the present invention will appear on reading the following description of certain preferred embodiments.

This description will be made with reference to the appended drawings in which:

FIG. 1 is a simplified top view of a document-value consisting of a banknote and comprising a security element according to a first embodiment of the invention;

- Figure 2 is a greatly enlarged top view of a portion of the security element visible in Figure 1, before it is deformed;

FIG. 3A is a perspective view of a portion of an etching plate making it possible to obtain a security element according to a first embodiment of the invention;

FIG. 3B represents a perspective view of three contiguous lines of a network integrated with the security element, according to a first variant of an embodiment of the invention, obtained with a plate as described with reference to Figure 3A;

- Figures 4A and 4B are views equivalent to the preceding figures, a plate and a security element, according to a second embodiment. ;

- Figure 5A is a top view and partial of the security element of Figure 1, after deformation;

FIGS. 5B and 5C are end and opposite views of the element of FIG. 5A;

FIG. 5D is a partial cross-sectional view of the security element of FIG. 5A at the reference point of inflection.

FIGS. 6 and 7 are end and perspective views respectively of a third and a fourth embodiment of the invention;

FIG. 8 is a plan view of a numismatic printing integrated into a security element such as that of the invention;

- Figures 9 and 10 are very enlarged views and at different scales of a printing plate intaglio to obtain the security element that appears in Figure 3B;

- finally, Figures 1 1 and 12 are very enlarged views and at different scales of a printing plate intaglio to obtain the security element that appears in Figure 4B.

By convention, the numerical references relating to the printing plates of the "prime" index will be applied throughout the present application. Under these conditions, the same numerical reference, with or without the index "prime" designates the same element of the plate, respectively of the security element.

There is shown in Figure 1 a document of value 1 consisting of a bank note.

In the traditional way and in the example presented here, the bill has on at least its front face, an indication of its value referenced 10 (in this case 100), and a decoration referenced 1 1, here representing a portrait.

Also visible on this bank note 1 to the left of the portrait, a security element 12 according to the invention. The valuable document 1, in this case the bank note, is made of paper or of fibrous material, or alternatively, of a plastic embodiment or of a combination of these materials.

The security element 12 is either reported or integrated in the ticket.

In the latter case, it means that it is in one piece with said ticket.

This security element, according to a feature of the invention, comprises a colored network which consists of a repetition of contiguous strips 3 formed of adjacent or contiguous nets of at least two different colors.

In the case shown in FIG. 2, each strip is formed of three parallel threads 120, 121 and 122 respectively having different colors.

In this specific embodiment, the threads 120 identified by small crosses have the blue color referenced B.

The nets 121 immediately contiguous and illustrated here by small circles have a red color referenced R.

Finally, the third thread 122, which is devoid of locating means in the figure, is yellow and referenced J.

Of course, according to other embodiments, one could choose other color combinations.

The pitch (i.e., the width of each band) and the width of each net are respectively referenced Pi and L-i.

Preferably, at an observation angle perpendicular to the plane G in which the support of the security element is contained, the width Li of the nets 120 to 122 is such that the colors B, R and J can not be distinguished. one from the other with the naked eye. In other words, the eye perceives a combination of these colors.

Particularly advantageously, the pitch Pi is of the order of 400 μm, while the nets 120 to 122 of color forming each strip 3 are of the same width L-i.

In another embodiment not shown, it could be a different number of colors, for example two or four.

These nets are not necessarily contiguous; they can simply be adjacent. In the case where the white color is used, this color results from a lack of coloration or a coloring in white.

In the case of a lack of coloring, it is the color, in this case the white of the support which appears directly.

The security element 12 is preferentially colored by an offset type printing process.

In Figure 3 is shown partially in perspective, a plate for obtaining a first embodiment of the security element according to the invention.

This plate comprises a network 14 'of lines 16' in relief, substantially parallel. These lines 16 'have, in cross section, a triangular shape.

The two flanks of these lines have been designated by the references 17Ά and 17'B.

Here, the angle of inclination ₂ of the sidewall 17'B of a line 16 'varies gradually along this line, while the angle αΊ of inclination of the sidewall 17Ά gradually changes in the opposite direction. Thus, the two sides 17Ά and 17'B opposite two contiguous lines of the network 14 'meet forming a groove 21' of constant depth.

It is referenced H 'the height of the reliefs, L' ₂ the width of the lines 16 'and 1 / 2T' the half-frequency of variation of the aforementioned angles

In Figure 3B is shown a portion of the security element obtained with the plate of Figure 3A. Its shape is exactly the opposite (complementary) to that of the plate.

In this case, this security element includes a network

14 of lines 16 in relief, substantially parallel. These lines 16 have, in cross section, a triangular shape.

The two flanks of these lines have been designated by references 17A and 17B.

Here, the angle? ₂ of inclination of the 17B side of a line 16 gradually varies along this line, while the angle CM 17A flank inclination varies gradually in the opposite direction. Thus, the two sides 17A and 17B vis-à-vis two adjacent lines of the network 14 join together forming a groove 21 of constant depth.

Of course, the parameters H, L ₂ and 1 / 2T are strictly equal to H ', L' ₂ and 1 / 2T. As illustrated in FIG. 4A (second embodiment), the plate also comprises an array 14 'of lines 16' in relief. Each line comprises at least flanks 17Ά and 17'B defining an angle of inclination αΊ with respect to a direction normal to the plane of the grating 14 '(this direction is shown schematically by an axis z on the Cartesian coordinate system (x), (y) ) and (z) indicated in the figures.

In this example, each line 16 'has a generally rectilinear shape, and the lines 16' of the grating 14 'are parallel to one another.

The angle of inclination αΊ of the flank 17Ά of at least one line 16 'of the grating 14' varies gradually along this line 16 '.

In Figure 4B is shown a portion of the security element obtained with the plate of Figure 4A.

The angle of inclination ai of the sidewall 7A of at least one line 16 of the grating 14 varies gradually along this line 16 so as to form in light reflection a changing optical effect as a function of the observation angle of the security element 12.

In fact, this gradual variation is sinusoidal.

Under this network appears the colored frame described with reference to Figure 2.

In both embodiments of Figures 3B and

4B, the pitch L ₂ of each line is equal to the pitch Pi of the colored network of FIG. 2.

In Figure 4B is also shown the colored frame of Figure 2.

FIG. 5A is a top view, under a microscope, of a security element integrating both a colored network and a deformed network.

Note that this deformation is carried out by embossing the support, in particular according to the so-called dry stamp technique, namely intaglio without ink.

In this figure, there is the presence of a juxtaposition of contiguous bands of color, namely three different colors.

In this embodiment, the grooves 21 which separate each line 16 are always at the same altitude and rectilinear, while the peak 20 moves in a sinusoid S whose inflection point is referenced Si. In this figure, the eye of an observer is referenced by the numeral 15, which looks laterally at the security element under intense illumination.

The periodic nature of the inclination of the flanks results in two phenomena.

On one hand at certain angles, the flanks are oriented orthogonally to the direction of observation, which maximizes the observed surfaces. On the other hand, the ridge masks the opposite flanks. Since this peak is periodic and moves, the colors of the threads of the bands are exposed alternately.

Moreover, the fact that the paper deforms by embossing reflects a certain plasticity of it. But by deforming it, one also lengthens mathematically the path of a point which would traverse transversely the embossed network.

As regards the colored nets, the same phenomenon comes into play. The width of the bands formed of three contiguous nets measure, for example 400 μm. The lines of the etching plate have an identical width of 400 μm, but because of the addition of a third dimension, in this case the depth, the path for connecting the two transverse ends of said lines is increased. On the support now, assuming, for example, that in a given section line (perpendicular to the direction of extension of the lines of the network), a blue thread is at the top of a ridge and that it is extended on either side of this ridge, if one moves along the cutting line, the blue net will pass gradually from one side or the other depending on the direction of movement and leave the place in the contiguous net.

All these phenomena contribute to the appearance of a moiré effect resulting in a macroscopic iridescence, visible to the naked eye, of the colors constituting the nets and thus, in this way, to authenticate the element of security and the document on which it is affixed.

FIGS. 5B, 5C and 5D show the profiles of the deformations of two contiguous lines 16. In the views 5B and 5C, each line has the shape of a right triangle whereas in FIG. in the form of an isosceles triangle.

Of course, the visual effect is dependent on the height

H of the reliefs, of the period T of the sinusoidal evolution of the inclination of flanks of the reliefs and pitch P of angular variation of said flanks.

In Figure 6 is shown another embodiment in which the reliefs of each line have an isosceles triangle-shaped section, the peak of which is moving in height in a sinusoidal progression.

In the embodiment of Figure 7, we are dealing with a progression of the lines according to step stairs of progressive height.

In FIG. 8 is represented, within a network of color bands, an impression N of numismatic type made of a fraction of bands oriented in an arc of a circle. Together they constitute a C-shaped numismatic image.

In FIGS. 9 and 10 is a top view under an electron microscope of a printing plate in intaglio format corresponding to the embodiment of FIG. 3A. This plate is engraved in patterns complementary to those desired on the security element.

Likewise, in FIGS. 11 and 12 is shown, seen from above with an electron microscope, a printing plate in intaglio mode corresponding to the embodiment of FIG. 4A.

Preferably, the following parameters have the values indicated below:

Period of periodic movements: T is between 0.5 and 50 mm, preferably between 5 and 25 mm.

Depth of engravings on plates: P is between 1 and

200 microns, preferably between 40 and 150 microns, particularly 100 microns.

Width Lg of engraved plates: Lg is between 50 and 2000 microns, preferably between 200 and 600 microns, particularly 400 microns.

Width Lf of the threads and Lb of the strips: Preferably Lb = n x Lf (width of the threads) with n> 2. Preferably n = 3 and Lf = Lg / n. If Lg = 400 μm and n = 3, then Lf = 133.333 μm and Lb = 400 μm.

We can also consider different widths Lf provided that ΣLf = Lg. Embossed lines with periodic movements are not necessarily aligned transversely. They can be shifted line by line.

The colors of the threads can accommodate 2 ^nd level properties (fluorescent inks, phosphorescent, infrared, thermochromic, label etc.).

Claims

A security element (12) for a document-value (1) which consists of an initially plane support (G), comprising a network (14) of lines (16) in relief, each raised line (16). having a profile (F), said profile (F) having gradual shape variations along a given line (16) or line to line, said grating (16) being colored, characterized in that said colored network (16) consists of a repetition of contiguous strips (3) formed of threads (120, 121, 122) of at least two different colors (B, R, J), adjacent or contiguous, these strips (3) having the same direction as said lines (16) of said network (14).

2. Security element according to claim 1, characterized in that said variations are shaped so that the relief hides part of the threads (120, 121, 122), when viewed at an angle not perpendicular to said auditory plane (G), said portion varying gradually along the line (16) or from one line to another, showing a variation in color and / or brightness.

3. Safety element according to one of claims 1 or 2, characterized in that, at an angle of observation perpendicular to said plane (G), the width of said threads ( 120, 121, 122) is such that said at least two colors (B, R, J) can not be clearly distinguished from each other with the naked eye.

4. The security element according to one of the preceding claims, characterized in that said shape variation is periodic, such as a variation in height of the profile (F).

5. Safety element according to one of the preceding claims, characterized in that said profiles (F) comprise at least one flank (17A, 17B) each defining an angle of inclination (α-ι) with respect to a normal direction (z) to the network (14), said shape variation comprising a variation of the angle of inclination (α-ι) of the sidewall of at least one line (16) or at least two lines of the grating (14), gradually along this line (16), respectively from one line (16) to the other, so as to form in light reflection, a gradient optical effect changing according to an observation angle of the security element.

6. Security element according to claim 5, characterized in that said profiles have a generally triangular shape, two neighboring profiles each having a ridge (20), separated by a groove (21) and that said variation in shape consists of a variation of the position of the ridge (20) between two neighboring grooves (21) or a variation of the height (H) of the ridge (20).

7. Security element according to claim 5, characterized in that said grooves (21) are parallel to said strips (3).

8. Security element according to one of the preceding revendications ications, characterized in that the width of said strips (3) is substantially equal to that of the lines (16) in relief.

9. Security element according to one of the preceding claims, characterized in that the width of the bands is between 50 and 2000 pm, preferably between 200 and 600 pm, and even more preferably of the order of 400 pm.

10. Safety element according to one of the preceding claims, characterized in that the color threads (120, 121, 122) forming said strip (3) are of the same width.

11. A security element according to one of the preceding claims, characterized in that said strips (3) have, on at least a portion of their extent, a different orientation, so as to constitute at least one numismatic image.

12. A method of manufacturing a security element (12) according to one of the preceding claims, characterized in that is coated a support (G) generally plane said strips (120, 121, 122) colored and qu it is deformed using a printing plate (4) intaglio which has at least one engraved groove, of complementary shape to that of a line of said network (14).

13. Document-value (1) characterized in that it comprises at least one element according to one of claims 1 to 1 1.

14. Document-value according to claim 13, characterized in that the security element (12) is integrated therein or is related thereto.

15. Document-value (1) according to one of claims 13 or 14, characterized in that it is paper, fibrous material, plastic or a combination of at least two of these materials.