EP3254864A1 - Characteristic and method for its production - Google Patents

Abstract

The invention relates to a method for producing a feature (12), in particular for a security element, a security paper or a data carrier which has a region provided with a colored pattern (22, 48, 50) and at least one aperture (32) in the register. , a recess and / or a scribe, wherein a support (14) is provided which has at least in the area a coating (16) with a laser-sensitive substance which is modifiable by means of at least one first laser radiation (20) with respect to their color at least one first laser radiation (20) is irradiated onto the region of the carrier (14) in such a way that the colored pattern (22) is produced, wherein the at least one first laser radiation (20) modifies the substance with respect to its color, but no change of the carrier (14), and the at least one first laser radiation (20) also in a the colored pattern (22) surrounding edge strips (24) is inserted is irradiated in order to rule out that by tolerance fluctuations parts of the pattern (22) are not exposed to laser radiation (20), and by means of ablating, second laser radiation (26), which differs from the first laser radiation (20), the breakthrough (32) , the indentation and / or the scribe is produced in the carrier (14), which stands in the register to the colored pattern (22), wherein the second laser radiation (26) is irradiated also on the region of the carrier (14) in a frame-shaped section (36) which at least partially surrounds the colored pattern (22), the coating (16) is removed and / or the substance is dyed to a maximum, wherein the frame-shaped section (36) completely covers the edge strip (24).

Description

The invention relates to a method for producing a feature, in particular for a security element, a security paper and a data carrier which has a colored patterned area and at least one breakthrough in register, wherein the colored pattern is generated by a laser-active substance is used, which is modifiable by means of a first laser radiation in terms of their color, and the breakthrough is generated by means of ablative, second laser radiation.

Identification documents, such as credit cards or identity cards, are often laser engraved with an individual identifier. The production of continuous openings in value documents, eg banknote papers, by laser cutting has also been known for some time. For example, in the document DE 4334848 C1 describes a security with a closed by a transparent cover film window-like opening, which can be generated by a laser cutting process.

The WO 2009/003587 A1 describes a manufacturing method and a corresponding security feature that is produced by a laser cutting method by irradiating laser radiation from an upper side onto the carrier. The support of the security feature is previously coated on top with a marker which changes color by the action of laser beams. For the production of the hole or holes, a cutting laser beam is used whose intensity in the radiation cross section is non-uniform, for example, Gaussian, distributed. Due to this drop in intensity, an edge is formed at the top, on which the carrier is no longer cut, but a modification of the marker takes place with regard to its color effect. In this way, the edge region of the hole produced by means of laser radiation appears colored at the top. This effect is from the WO 2011/154112 A1 and WO 2010/072329 A1 known.

A colored border of holes is also from the WO 2009/003588 A1 However, several laser beams of different intensities are required in order to achieve a particularly large and thus well-recognizable color effect.

Laser radiation-sensitive markers are known, for example, from the following publications: EP 1657072 B1 . EP 2332012 B1 . EP2528742 B1 . US 7270919 . US 7485403 . US 7998900 . US 8021820 . US8048608 . US8048605 . US 8083973 . US 8101544 . US 8101545 . US 8105506 . US 8173253 . US 8178277 . US 8278243 . US 8278244 and US 842028 ,

From the EP 1641627 B1 A method for applying markings on both sides of a security paper is known, wherein the processing takes place from one side. In order to provide the page opposite side of the paper with a security mark, laser radiation is radiated through the paper, wherein the laser radiation ablated on the opposite side applied photosensitive layer or changed in color. The WO 98/36913 is also concerned with the creation of security markings on both sides of a security paper, using a laser beam which simultaneously performs an ablation on the front and back of the security paper so as to produce identical markings on both sides.

The DE 102010053052 A2 discloses a data carrier containing a marking produced by the action of laser radiation, which produces a different visual impression when viewed, than in a plan view.

The DE 102008046513 A1 discloses a security element which is partially provided with a metallization. Above these sections and also next to it, a laser-sensitive marking substance is applied as a coating. By means of laser radiation, a deliberate color change in the coating is produced in the areas next to the metallization. Sections in which the coating overlies the metallization are also laser treated in such a way that both the coating and the metallization are removed. Thus, a negative pattern is generated in the metallization, which is due to the targeted introduction of the laser radiation in perfect registration to the adjacent areas in which the color change was triggered on the coating.

In the DE 102010053052 A1 It is described to form cutting lines in a substrate in perfect registration to demetallization lines by generating both line types by laser application with the same processing laser beam in the same operation and varying a laser parameter, for example laser power and / or cutting speed.

The EP 2528742 B1 describes a laser arrangement in which a scanning deflection of a laser beam is replaced by the line or grid arrangement of a plurality of diode lasers. This allows a faster processing speed can be achieved. The resolution depends on the number of diode lasers used. A typical resolution is 400 dpi. The number of diode lasers, the resolution and the width of a carrier web to be processed, the so-called processing width, are linked together. The wider the machining width should be, the lower the resolution or the greater the number of diode lasers needed. Similarly, the resolution decreases as the number of diode lasers decreases, or as the width of the carrier web to be processed increases.

The invention has for its object to provide a method for producing a feature having a provided with a colored pattern area and standing in the register to at least one breakthrough, depression and / or scribe, with a high registration accuracy is achieved and at the same time Production with respect to the introduction of the laser radiation is simplified.

1. (a) ein Träger bereitgestellt wird, der mindestens im Bereich eine Beschichtung mit einer lasersensitiven Substanz aufweist, die mittels mindestens einer ersten Laserstrahlung hinsichtlich ihrer Farbe modifizierbar ist,
2. (b) die mindestens eine erste Laserstrahlung auf den Bereich des Trägers so eingestrahlt wird, dass das farbige Muster erzeugt wird, wobei
   • die mindestens eine erste Laserstrahlung die Substanz hinsichtlich ihrer Farbe modifiziert, aber keine Veränderung des Trägers bewirkt, und
   • die mindestens eine erste Laserstrahlung auch in einem das farbige Muster umgebenden Randstreifen eingestrahlt wird, um auszuschließen, dass durch Toleranzschwankungen Teile des Musters nicht mit Laserstrahlung beaufschlagt werden, und
3. (c) mittels abtragender, zweiter Laserstrahlung, die sich von der ersten Laserstrahlung unterscheidet, der Durchbruch, die Vertiefung und/ oder die Ritzung im Träger erzeugt wird, der/die im Passer zum farbigen Muster steht, wobei die zweite Laserstrahlung auch auf den Bereich des Trägers so eingestrahlt wird, dass in einem rahmenförmigen Abschnitt, der das farbige Muster mindestens teilweise umgibt, die Beschichtung entfernt und/ oder die Substanz maximal gefärbt wird, wobei der rahmenförmige Abschnitt den Randstreifen vollständig überdeckt.

The object is achieved by a method for producing a feature, which is preferably provided on a security element, a security paper or a data carrier, which is provided with a colored pattern area and standing in the register to at least one breakthrough, depression and / or scribing having,

1. (a) providing a carrier which has at least in the region a coating with a laser-sensitive substance which is modifiable in terms of its color by means of at least one first laser radiation,
2. (B) the at least one first laser radiation is irradiated on the region of the carrier so that the colored pattern is generated, wherein
   • the at least one first laser radiation modifies the substance with respect to its color but does not cause any change in the carrier, and
   • the at least one first laser radiation is also irradiated in an edge strip surrounding the colored pattern in order to preclude that parts of the pattern are not exposed to laser radiation by tolerance fluctuations, and
3. (C) by means of ablative, second laser radiation, which differs from the first laser radiation, the aperture, the recess and / or the scribe is generated in the carrier, which stands in the register to the colored pattern, wherein the second laser radiation on the area the support is irradiated so that in a frame-shaped portion which at least partially surrounds the colored pattern, the coating is removed and / or the substance is stained maximum, wherein the frame-shaped portion completely covers the edge strip.

The manufacturing method combines two laser beams, wherein the at least one first laser radiation generates the colored pattern in the laser active substance and the second laser radiation generates both the aperture, the recess and / or the scribe and in a frame-shaped portion surrounding the pattern, the coating , in which the laser-active substance is applied, removed and / or the substance stains maximum. In this way, the at least one laser radiation which modifies the substance with respect to its color can be irradiated with a much lower resolution than would be required for the register. The first laser radiation outshines the pattern, so it is also irradiated in an edge strip surrounding the colored pattern. This ensures that parts of tolerances or lower resolution of the first laser radiation do not undesirably leave parts within the pattern free. The second laser radiation removes the coating with the laser-sensitive substance in the marginal strip or dyes the substance to a maximum and thus creates a frame-shaped section which surrounds the colored pattern. He is either colorless or completely colored to the highest degree of coloration to which the substance is capable and forms a frame around the pattern.

Thus, the resolution of the first laser radiation is no longer relevant to the accuracy of the passport, but only the accuracy with which the second laser radiation is applied. Since this also produces the breakthrough, the depression and / or the scribe, the registration to the colored pattern is carried out exclusively by the accuracy with which the second laser radiation is irradiated and ultimately also the aperture etc. is generated. Thus, the aperture etc. and the colored pattern are in register accuracy with each other, which is predetermined solely by the precision with which the aperture, recess and / or score is created and placed.

As used herein, the term "resolution" is intended to denote not only the size of minimum features, but also the exactness of the positioning of the first laser beam, i.e., the location of carrier and first laser radiation.

The sequence of irradiation of the first laser radiation and of the second laser radiation can also be understood in such a way that the first laser radiation generates the pattern over a large area, the difference to the target shape being due to the resolution of the first laser radiation. The second laser beam cuts the pattern to a desired outline by ablation or complete staining.

This procedure makes it possible to use a much more productive laser beam source for the first laser radiation in terms of production, for example laser diode arrays as described in US Pat EP 2528742 B1 are known.

The order in which the first and second laser beams are irradiated is not specified. There are two possibilities. In a first option, the at least one first laser radiation is first applied, that is to say the colored pattern is formed in the region and a color effect is also triggered in the edge strip. In this way, irrespective of the resolution with which the first laser radiation is irradiated, it is ensured that the pattern is completely produced, since the first laser radiation is also introduced into the edge region which surrounds the pattern. Subsequently, the aperture, the recess and / or the scribe is produced by means of the second laser radiation and the colored pattern is cut by removing the coating with the discolored laser-sensitive substance in the frame-shaped section or fully dyed through. The latter variant creates a frame around the pattern. To ensure that the discolored edge strip is also completely processed, the second laser radiation is irradiated in such a way that the frame-shaped section completely covers the edge strip.

In a second option, the second laser radiation is first radiated in, ie the frame-shaped section is created which surrounds the (at this time still to be generated) colored pattern. Subsequently, the at least one first laser radiation is irradiated onto the carrier and the colored pattern is generated. Again, the first laser radiation is guided over the edge strip. In contrast to the first option, however, no (further) color effect arises here, since the second laser radiation has already removed or completely colored the coating in the preceding step.

The generation of the breakdown, the depression and / or the scoring with the second laser radiation will generally be effected in that the fluence of the second laser radiation is then higher than for the removal or staining of the coating in the frame-shaped section. Inverse applies to the feed rate of the second laser radiation.

As already mentioned, laser-sensitive substances are known which can be colored differently in multistage processes. It is therefore preferred that a plurality of first laser radiations are used which produce the color modification. For example, a first laser radiation can cause an activation of the substance and another a color change. So is from the already mentioned EP 2528742 B1 a laser-sensitive substance is known, which is colored with a multi-stage process, here a three-stage process. Two-stage systems are also known to the person skilled in the art, for example in which a first stage activates the laser-sensitive substance and a second stage triggers the color change. It is now possible to remove the opaque layer with the laser radiation according to the first step in the pattern and to activate the laser-sensitive substance in the entire pattern. The second stage of irradiation of the laser radiation, which usually takes place at a different wavelength, then causes the triggering of the color effect with the desired structuring within the pattern. The laser radiation of the plurality of stages can be effected in succession in time, for example when passing through a processing section, or also simultaneously in time through a corresponding radiation mixture.

Of course, the invention is not limited to the fact that a color effect is either triggered or not. It is equally possible that instead of a yes / no effect of the laser radiation, the color effect in the sense a gradation can be graded. This can be achieved, for example, the variation of the fluence of the first laser radiation, ie, then the intensity of the first laser radiation is varied to produce different intense color changes.

It should be noted that the pattern may provide motifs, images or alphanumeric characters.

The substance need not be further structured or specially applied for the registration between pattern and breakthrough. It is even possible to provide them over a whole area in a much larger area than the surface treated with laser radiation occupies.

As a substance with advantage markers come into question whose visible color is changed by the action of the laser radiation. For example, thermoreactive colored pigments such as ultramarine blue can be used for this purpose. Advantageously, it is also possible to use marking substances whose infrared-absorbing properties or their magnetic, electrical or luminescent properties are changed by the action of the laser radiation. It is also possible to use a combination of different marking substances, for example in order to enable both a visual and a machine authenticity check of the (security) feature. When using several markers, these can come to lie next to each other as well as in different layers one above the other.

According to an advantageous variant of the invention, laser radiation-modifiable effect pigments are used as the laser-radiation-modifiable marker. Such effect pigments are available to the person skilled in the art with different Properties, in particular with respect to their body color, the color change under laser radiation, the threshold energy and the required laser radiation wavelength available. Also, effect pigments which change not only their visible color under laser radiation but their infrared-absorbing, magnetic, electrical or luminescent properties are known to the person skilled in the art. The modification of the effect pigments can be carried out with laser radiation in the ultraviolet, visible or infrared spectral range.

In a further likewise advantageous variant of the invention, a pigment-free laser-radiation-modifiable marker is used. Pigment-free marking substances can also be applied to the support, for example as a stich or printing ink. With pigment-free marking materials, a coating of high transparency can be produced, into which a permanent and high-contrast marking can be introduced by laser action at high speed. Pigment-free markers can be modified by laser radiation in the ultraviolet, visible or infrared spectral range. Specific, non-limiting examples of pigment-free laser-modifiable markers are in the references WO 02/101462 A1 . US 4343885 and EP 0290750 B1 specified, the disclosure of which is included in the present description in this regard.

The second laser radiation is irradiated positionally accurate to the first laser radiation. In particular, the irradiation takes place in the same operation and / or in the same transport section of the carrier. As a transport section for the carrier can be considered one of several sections in a system through which the carrier is transported, which lies in particular between two pulleys of the transport system.

The laser sources are preferably arranged directly one behind the other. A positional deviation of less than +/- 0.3 mm between the two irradiated laser beams can be achieved, more preferably less than +/- 0.1 mm are achieved.

As far as the terms "front" and "back" are used in this description, they refer to the irradiation of the laser radiation. The front side is the side on which the laser radiation is irradiated, the back side is the opposite side of the carrier. The carrier is flat. The terms front and back have nothing to do with a later use of the wearer. The term choice is not intended to imply that one of the pages must or may not have a particular meaning for use. Insofar as the terms "above" and "below" are used in this description, this position specification also refers to the direction of incidence of the laser radiation.

The term "color" is not limited to a colorful impression, but can also include white and black, grayscale and the change between transparent and opaque. Multicolor is here to be understood as "colorful".

Further exemplary embodiments and advantages of the invention are explained below with reference to the figures, in the representation of which a representation true to scale and proportion has been dispensed with in order to increase the clarity.

• Fig. 1 eine Draufsicht auf eine Banknote mit einem Sicherheitsmerkmal,
• Fig. 2 eine Schnittdarstellung durch eine erste Ausführungsform des Sicherheitsmerkmals der Banknote der Fig. 1 während einer ersten Phase der Herstellung, in welcher erste Laserstrahlung aufgebracht wird,
• Fig. 3 eine Schnittdarstellung ähnlich der Fig. 2 während einer zweiten Phase der Herstellung, in welcher zweite Laserstrahlung aufgebracht wird,
• Fig. 4 eine Schnittdarstellung durch das Sicherheitsmerkmal nach Abschluss der Herstellung,
• Fig. 5 eine Draufsicht auf eine zweite Ausführungsform des Sicherheitsmerkmals, in der herzustellenden Form,
• Fig. 6 eine Darstellung ähnlich der Fig. 5 nach einer ersten Stufe der Herstellung, in welcher erste Laserstrahlung aufgebracht wurde,
• Fig. 7 eine Darstellung ähnlich der Fig. 6 nach Abschluss des Herstellverfahrens, nachdem auch zweite Laserstrahlung aufgebracht wurde,
• Fig. 8 eine Darstellung einer dritten Ausführungsform eines Sicherheitsmerkmals nach Abschluss eines ersten Herstellungsschritts, indem Laserstrahlung, die in den Ausführungsformen der Fig. 1 bis 7 zweite Laserstrahlung war, zuerst verwendet wurde, und
• Fig. 9 das Sicherheitsmerkmals nach Abschluss der Herstellung, d.h. nachdem Laserstrahlung, die in den Ausführungsformen der Fig. 1 bis 7 erste Laserstrahlung war, aufgebracht wurde.

Show it:

• Fig. 1 a top view of a banknote with a security feature,
• Fig. 2 a sectional view through a first embodiment of the security feature of the banknote of Fig. 1 during a first phase of production, in which first laser radiation is applied,
• Fig. 3 a sectional view similar to the Fig. 2 during a second phase of the production in which second laser radiation is applied,
• Fig. 4 a sectional view of the security feature after completion of the production,
• Fig. 5 a plan view of a second embodiment of the security feature, in the form to be produced,
• Fig. 6 a representation similar to the Fig. 5 after a first stage of production in which first laser radiation was applied,
• Fig. 7 a representation similar to the Fig. 6 after completion of the manufacturing process after second laser radiation has been applied,
• Fig. 8 a representation of a third embodiment of a security feature after completion of a first manufacturing step, by laser radiation, which in the embodiments of the Fig. 1 to 7 second laser radiation was used first, and
• Fig. 9 the safety feature after completion of the production, ie after laser radiation, which in the embodiments of the Fig. 1 to 7 first laser radiation was applied.

The production of a feature is explained using the example of a security feature of a banknote. Fig. 1 shows a schematic representation of the banknote 10, the security feature 12 is generated using a manufacturing process, for the various embodiments with reference to Fig. 1 to 10 be explained in more detail.

The security feature 12 has a colored pattern, which in the register to a breakthrough, depression and / or scribe, here z. B. is a hole. The embodiments here have in common that on a carrier 14 laser-sensitive substance in the form of a coating 16 is applied, which is modified by means of first laser radiation in terms of their color impression in a pattern. Further, in the carrier 14 is a depression, a scribe and / or an opening, z. B. in the form of a hole, incorporated breakthrough etc. and colored pattern in the register should be. Further, all embodiments have in common that the aperture, the recess and / or the scratching is generated by means of a second laser radiation, which differs from that with which the colored pattern is generated in the coating 16 of the laser-active substance.

As will be explained below, the manufacturing method is designed such that the precision requirements with which the first laser radiation generates the colored pattern are lower than the precision requirements for the second laser radiation, without adversely affecting the register between the hole and the colored pattern would.

In a first embodiment, the colored pattern in the coating 16 is first generated by irradiation of radiation from a beam source 18. The laser radiation 20 changes the color of the laser-sensitive substance. It is also possible to structure the pattern in different gray levels or color levels by means of suitable intensity modulation.

The laser radiation 20 is in the sense of this description a first laser radiation, wherein, as will be explained later, the term "first" is not limited to a chronological order. Rather, it serves to distinguish from the laser radiation, which later generates the hole, which is referred to as second laser radiation.

The method begins with the provision of a carrier 14 to which the coating 16 is applied. Of course, the coating can also be applied in the context of the process. Subsequently, the laser-sensitive substance is modified in terms of color by means of the laser radiation 20.

The first laser radiation can particularly preferably consist of a laser beam source array, for example a diode array according to FIG EP 2528742 B1 and generates in the coating 16 the pattern with a first resolution.

Fig. 3 shows a sectional view after completion of this manufacturing step. On the carrier 14, the coating 16 can be seen, in which a colored pattern 22 was formed by the first laser radiation 20. The colored pattern 22 in the illustration of Fig. 3 is surrounded by a marginal strip 24, which forms the edge of the colored pattern at this stage of manufacture. The different hatching in Fig. 3 are therefore registered, to illustrate the different division into colored pattern 22 and edge strip 24. The edge strip 24 can be considered as an unnecessary edge of the pattern 22 - to what extent it is not needed, will become apparent from the following description. It is dimensioned in particular at the first resolution with which the first laser radiation 20 was irradiated. It is dimensioned so that the colored pattern is definitely formed entirely within a target area.

Now, in another step, as in Fig. 3 is shown, second laser radiation 26 applied, which in this embodiment has no color-changing effect, but a erosive effect. The second laser radiation 26 originates for example from a CO2 laser 28 whose laser beam is guided by means of a scanner 30 over the coating 16. The second laser radiation 20 is now irradiated with a second resolution, which is optionally higher than the first resolution, so that an in Fig. 4 shown hole 32 is incorporated in the carrier 14. Next, the coating 12 is ablated in the edge strip 24 by means of the second laser radiation 26. This is done in a single operation, resulting in almost no tolerances between the hole hole 32 and frame 36. As a result, as a rule, a recess 34 is formed in the carrier 14. The ablation on the edge of the desired colored pattern 22 thus creates a frame section 36 which completely removes the edge strip 24. The width B of the frame portion 36 is thus at least as large as the edge strip 24. In Fig. 4 By way of example, a situation is shown in which the frame portion 36 has a width B which is greater than the width b of the edge strip 24. Further, purely by way of example, the inner (relative to the pattern 22) edge of the frame portion 36 is congruent with the inner edge of the Marginal strip 24. Both designs are optional. It is essential only that the frame section 36 covers the edge strip 24 and is arranged so that it limits the target surface of the colored pattern 22.

In the embodiment of the Fig. 1 to 4 First, the first laser radiation 20 and then the second laser radiation 26 was applied. This order can also be inverted, ie first the hole 32 and the frame portion 36 are generated and then formed with the first laser radiation 20 in the remaining area, the pattern 22, the second laser radiation is at least partially directed into the frame portion 36, where they due to the already removed or completely colored coating 16 no (further) colored effect can trigger more. Ultimately, one then obtains the state in the same way Fig. 4 ,

The Fig. 5 to 9 show in plan further embodiments for the manufacturing method of the security feature. Fig. 5 shows in plan view a target design, which should have the security feature 12. The target design in this case is a star-shaped hole 32 with colored tips 38 which should lie in exact register with the hole 32.

Fig. 6 shows the first stage of production after application of the first laser radiation 20. At the locations of the tips 38 colored fields 40 are applied. The location of the later hole 32 is shown as outline 42. For example, as shown by the mismatch at location 44, the peaks 38 do not lie in sufficient register with the outline 42 and thus with the later hole 32.

Fig. 7 shows the completion of the manufacturing process after introducing the hole 32 by means of the second laser radiation 26. The frame sections 36 produced by the second laser radiation 26 in the form of a frame line 46 Each color field 40 cuts exactly to the shape of the desired tip 38 and almost perfectly to the hole 32, since both are done in one operation. Thus, the first laser radiation 20 could be applied much more imprecisely than would actually be necessary for the tips 38. Nevertheless, after completion of the manufacturing process, the tips 38 are in exact registration to the hole 32 and have exactly the desired shape.

Fig. 8 shows a further embodiment in the example, on the one hand, the order of the two processing steps is reversed. First, a hole 32 is produced with the second processing laser radiation and in one operation the frame sections 36 in the form of a picture frame. Subsequently, an image 48 and a frame structure 50 are generated with the first laser radiation as a black-and-white pattern. Both are due to the preparation, ie the frame portions 40 and the hole 32 in perfect register to the hole 32 and also have exactly the desired dimensions, since the frame portion 36 prevents that by the lower resolution with which the laser radiation 20 is applied, the image 48th and the frame structure 50 would be in undesirable locations. On the other hand are in Fig. 8 the frame sections not by removing the coating, but by complete coloring by means of low intensity second laser radiation 26 generated. They form a colored, here black framing.

In the embodiments of the Fig. 2 to 4 the color change in the laser-sensitive substance takes place by adjusting the intensity of the laser beam, ultimately the area density, ie fluence, at the surface of the material to be processed. However, the intensity is not the only parameter that can be varied with the introduction of the laser radiation. Ultimately, the parameter depends on the laser-sensitive substance. For a laser-sensitive Substance that can be brought to color change only very narrow band, for example within a certain absorption band, could also be the variation of the laser radiation wavelength used as a parameter. The same applies to a variation of the polarization.
It can also be used a laser-sensitive substance, which is brought in a multi-stage process for color variation. Such a multi-stage process is for example from the already mentioned EP 2528742 B1 known. The laser-sensitive substance disclosed therein can be modified by a three-stage process so that a multicolor is possible.

The manufacturing method is particularly advantageous to apply when used for the first laser radiation as a beam source, a diode laser array, either in the form of a diode laser bar or in the form of a diode laser stack. A typical resolution for such diode lasers is 400 dpi. A common wavelength is in the near infrared range, e.g. at 1 .mu.m, in particular at 978 nm. With lasers of this wavelength, the carrier 14, for example paper, can not usually be cut, since the carrier is too transparent for this wavelength. It is therefore provided in preferred embodiments that the first laser radiation is applied so that it does not change the carrier 14 or can not change. The second laser radiation is in a spectral range with which the carrier 14 can be cut well, for example in the mid-infrared range, for. B. at 10.6 microns.

The invention has the advantage that the first laser radiation can be provided so that it can process surfaces very quickly. In particular, a high-resolution and generally slow scanner 30 can be dispensed with.

Instead of only turning on and off the beam source for the first laser radiation, for example a diode laser, to produce a black-and-white image, the power can also be regulated to obtain a gray-scale image. In a diode laser array, each individual diode laser can usually be regulated in power. This makes it possible to produce a grayscale image instead of an b / w image. If a substance is used that responds to both CO2 laser radiation and diode laser radiation, a grayscale image well-matched to the laser hole can be generated. For this purpose, a laser-sensitive substance can be used which exhibits a high-contrast color change at one of the two wavelengths (eg 10.6 μm). So that a high-contrast color change can then also be achieved at the other wavelength (for example 1064 nm), a corresponding NIR absorber additive is optionally introduced into a binder matrix of the coating 16. A binder of the coating 16 has high transparency for both wavelengths, so that the laser radiation can penetrate unhindered to the pigment without being absorbed by the binder itself.

The edge effect is difficult to counterfeit. The slight registration tolerances of the coloring with the first laser radiation are quasi absorbed by the frame sections 36. Despite a pass tolerance of, for example, +/- 0.1 mm for the first laser radiation, the image 48 and the frame structure 50 can nevertheless be arranged with a registration which is predetermined exclusively by the accuracy of the second laser radiation.

LIST OF REFERENCE NUMBERS

10

bill

12

security element

14

carrier

16

coating

18

first beam source

20

first laser radiation

22

colored pattern

24

edge strips

26

second laser radiation

28

second beam source

30

scanner

32

hole

34

deepening

36

frame section

38

top

40

colored field

42

outline

44

mismatching

46

frame line

48

image

50

frame structure

B, b

width

Claims (9)

A method of making a feature (12) having a colored patterned portion (22, 48, 50) and having at least one aperture (32), indentation and / or score therewithin (a) providing a carrier (14) which has at least in the region a coating (16) with a laser-sensitive substance which is modifiable in terms of its color by means of at least one first laser radiation (20), (B) the at least one first laser radiation (20) on the area of the support (14) is irradiated so that the colored pattern (22) is generated, wherein - The at least one first laser radiation (20) modifies the substance in terms of their color, but causes no change in the carrier (14), and - The at least one first laser radiation (20) in a colored pattern (22) surrounding the edge strip (24) is irradiated in order to exclude that tolerance variations parts of the pattern (22) are not acted upon by laser radiation (20), and (c) by means of ablating, second laser radiation (26), which differs from the first laser radiation (20), the breakthrough (32), the recess and / or the scribe in the carrier (14) is generated in the register to the colored pattern (22), wherein in one operation, the second laser radiation (26) is irradiated also on the region of the support (14) so that in a frame-shaped portion (36), the colored pattern (22) at least partially surrounds the coating (16) removed and / or the substance is colored to the maximum, wherein the frame-shaped portion (36) completely covers the edge strip (24). The method according to claim 1, wherein step (c) is carried out before step (b) by irradiating the at least one first laser radiation (20) on the marginal strip (24) there due to the coating (16) removed in the frame-shaped section (36) maximum colored substance is no longer modifiable in color further substance is present. Method according to one of claims 1 to 2, wherein the second laser radiation (26) in the frame-shaped portion (36) is irradiated with lower fluence, as in the generation of the aperture (32). Method according to one of claims 1 to 3, wherein the laser-active substance is modifiable in terms of their color in a modification process comprising at least two stages, wherein in both stages first laser radiation (20) is irradiated and the steps with respect to a wavelength of the first laser radiation (20) differ. The method of claim 4, wherein the one wavelength of the first laser radiation (20) causes activation of the substance and another color change of the substance. Method according to one of claims 1 to 5, wherein the first laser radiation (20) a grayscale or color step image (50,48) is generated. Method according to one of claims 1 to 6, wherein the second laser radiation (26) is irradiated positionally accurate to the first laser radiation (20) on the carrier, preferably with a positional deviation of less than +/- 0.3 mm, more preferably of less than + / - 0.1 mm. Method according to one of claims 1 to 7, wherein the second laser radiation (20) by means of a scanner (30) via the carrier (14) is deflected and the first laser radiation (20) is provided by a driven laser array. The method of any one of claims 1 to 8, wherein the frame-shaped portion (36, 46) limits or cuts the pattern (22, 48, 50) to a desired extent.

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