DE102005052562A1 - Method for production of safety element with optically variable structure, involves providing substrate with marking structure with many flat markings and relief structure with many reflex relief elements - Google Patents

Abstract

Method involves providing substrate (40) with a marking structure with many flat markings(24,26) and with relief structure with many reflex relief elements (22) whereby marking structure and relief structure are combined such that different information are visible from different reflection directions. Optically variable structure (20) having individualized character is produced with contact less procedure or print process on solid printing block. Independent claims are included for the following: (1) Safety element; and (2) Application of safety element.

Description

The The invention relates to a security element with an optically variable Structure containing an individualization indicator, as well a method for producing such a security element. The invention further relates to a with such a security element equipped disk.

To the Protection against imitation, especially with color copiers or comparable reproduction methods, will be data carriers, such as for example banknotes, securities, certificates, vouchers, checks, high-quality tickets, but also other counterfeit securities, such as credit cards, Passports and other identification documents, as well as product protection elements, such as Labels, seals and packaging, with optically variable security elements fitted. The counterfeit protection is based mainly on the fact that the optically variable effects for the visually simple and clear to recognize human observers they are not, however, with today's known reproductive devices can be imitated Since these are the optically variable elements always only from one line of sight play.

at the same time should such disks often include an individualization or personalization, like such as a numbering on banknotes or personal data or a photograph for ID documents. These individual components of the disk compete with other security elements around the space on the disk.

As optically variable security elements for data carriers are for example from the document EP 0 801 604 B1 Relief structures known with tilting effect. These security elements essentially consist of a pre-grid of certain spatial frequency, which is combined with a flat coating grid of the same spatial frequency so that at least parts of the coating grid are visible when viewed vertically, but hidden under oblique viewing under a predetermined viewing direction. When alternately vertical and oblique viewing so creates a tilting effect.

The standard used printing and embossing procedures However, do not leave individual information for everyone Single use in the tilted picture too. On the other hand, would be the standard procedure for individualization of banknotes or value prints, the numbering used in book or high pressure, so would a previously introduced embossing partially destroyed. The order of printing can be reversed but difficult because the Personalization is generally used as the last print.

Further can because of the raster structures to fine line or Dot matrix, effect color, which due to their pigment size only in the relatively coarse screen printing can be applied, as a rule flat pressure can not be used.

One Another disadvantage is that the flat pressure and the corresponding Relief structure must be produced in two different passes, and This results in Passerschwankungen that even the tipping effect can not appear or only weak. Therefore, the tilting security elements become usually several times and slightly offset against each other on one disk arranged to ensure that the tipping effect at least in one of the elements appears well visible.

From the publication DE 199 47 425 A1 is a method for coating existing relief structures is known in which the relief material is coated by means of color droplets or pigments each at an oblique angle, so that the flanks are each colored with a particular color. However, this method requires an oblique orientation of the Farbtröpfchen- or pigment stream relative to the relief structure, preferably in an evacuated or over-pressurized area, which makes fast mass production difficult with conventional printing machines. Although the method allows a later, but no individual marking of the disk.

From that Based on the invention, the object is based, a generic security element which avoids the disadvantages of the prior art. In particular, the security element customization and connect optically variable effect in an advantageous manner and also at the high processing speeds required in securities printing let produce.

These Task is by the manufacturing process and the security element with the characteristics of the independent claims solved. Further developments of the invention are the subject of the dependent claims.

• a) Versehen eines Substrats mit einer Markierungsstruktur mit einer Mehrzahl flacher Markierungen; und
• b) Versehen des Substrats mit einer Reliefstruktur mit einer Mehrzahl erhabener Reliefelemente.

According to the invention, a method for producing a security element with an optically variable structure which contains an individualization indicator comprises the method steps:

• a) providing a substrate having a marking structure with a plurality of flat marks; and
• b) providing the substrate with a relief structure with a plurality of raised relief elements.

there the marking structure and the relief structure are combined that from different viewing directions different Information is visible and the customization indicator is in at least one of the steps a) or b) with a non-contact method or a printing process without a fixed printing form.

printing process without a solid printing plate are also referred to as non-impact printing methods or NIP methods. The term "non-impact" is based on a distinction to formerly usual "impact printers", where one Type or needles by impact the information on the paper has brought. Such systems were often by electrophotographic Procedure replaced, where the information about a laser contactless is transferred to an intermediate carrier, the latent charge image stored there is colored with a toner and then transferred to the paper becomes. Also in the NIP process there is therefore a contact during printing between the information color carrier and the paper, but the information is not transmitted "impact" (see Handbook of Print Media, eds: Helmut Kipphan, Springer, 2000, p. 709). In particular, the printing methods without a fixed printing form count Electrophotography, ionography, magnetography, ink-jet method and thermography (ibid., p. 711).

In In a first advantageous embodiment, the marking structure and the relief structure produced by the same method in one step. According to another, also advantageous embodiment Marking structure and relief structure in separate steps he testifies, with the marking structure before or after the relief structure can be generated.

In All embodiments are advantages of a space-saving connection achieved by security element and individualization of a data carrier, as well as an additional Security by the possibility the correspondence of security element and other individualizations, for example, the connection of a tilting element with a digit on a banknote.

Become the flat marks, for example, by laser color removal preprinted surfaces can be created for These also use effect colors, which because of their pigment size only in the Screen printing with a relatively high mesh size can be applied and therefore in the printing no fine resolution in the required spatial frequency allow. In this way, for example, color and information tilt effects can be connect with each other.

Especially if the flat marks and the relief elements of the relief structure is not created in grids of the same spatial frequency, it is not necessary, a weird one To maintain the angle between the two production steps.

By the creation of the reliefs is essentially in the substrate of the data carrier also the problem of abrasion of paint films in use prevents, as for example from the DE-692 09 185-T2 known method may occur. As is the relief Essentially located in the substrate, it has better durability also against other mechanical or chemical loads.

Becomes the marking structure and the relief structure with the same Device in In addition, there is no passer problem between Relief information and marking information. This can be done on it be omitted to represent the resulting tilting information multiple times.

The Substrate of the data carrier is in particular a coated or uncoated cotton paper or a coated or uncoated plastic film, in particular based on PVC, polycarbonate or PET.

According to a preferred embodiment of the method, the relief structure is embossed into the substrate. The embossing can be done for example with a stamping tool or in intaglio. According to another, likewise preferred embodiment, the substrate is provided with the relief structure by the action of a laser beam. The laser parameters for generating the relief structure are tuned in a conventional manner to the composition and the properties of the substrate, such as in the publications DE 102 47 591 A1 or DE 32 13 315 A1 described, the disclosure of which is included in the present application in this respect.

The relief structure is advantageously designed in the form of a grid, preferably a grid with a constant spatial frequency. It goes without saying that the term "halftone dot" is understood in the usual sense in printing technology and does not mean an expansion-free point in the mathematical sense. Possible raster arrangements include rasters with a constant period (constant dot size, constant dot pitch), amplitude modulated rasters (variable dot size, constant dot pitch), frequency modulated rasters (constant dot size, variable dot pitch), and higher order non-periodic rasters as described in the above-mentioned Handbook of Print Media on pages 44 ff. In addition to two-dimensional grids, one-dimensional grids (line grids) are also possible. The "grid points" are formed in this case by linear grid elements.

In an advantageous variant of the invention, the substrate by exposure a laser beam provided with the marking structure. The marking structure can be in a substrate body, such as a cotton paper or a plastic film, or in a on the substrate body applied layer can be introduced. After another, also advantageous Invention variant is the marking structure on the substrate printed. The marking structure, for example, in the ink-jet process or with applied to a low-pressure digital printing process become. In other embodiments, the marking structure becomes with advantage in planographic printing, such as in offset printing, in high pressure, such as in letterpress or flexographic printing, in screen printing or a thermography method, such as in the thermal transfer method, generated.

As the relief structure will also benefit the marking structure designed in the form of a grid, preferably in the form of a grid with constant spatial frequency, the flat markings forming the "grid points" of the grid. The possible Raster arrangements are the same as above in connection described with the relief grids.

The Rasters of relief structure and marking structure preferably have the same spatial frequency. However, it is also possible that Relief structure and the marking structure for the generation of beating or moiré effects train with slightly different spatial frequencies.

The Individualization indicator preferably comprises letters, Numbers or a symbol code, such as a bar or matrix code.

The Substrate and / or the surface of the security element contain additional safety substances, which in at least one of Steps a) or b) activated, exposed, covered, partially destroyed or removed.

The The invention also encompasses a security element with an optical element variable structure containing a marking structure with a plurality flat markings and a relief structure with a plurality of raised Contains relief elements, wherein the marking structure and the relief structure are combined in such a way that from different viewing directions different Information is visible. The marking structure and / or the Relief structure is provided with an individualization indicator, that with a non-contact Process or a printing process without a fixed printing form generated is.

The Relief elements of the relief structure and / or the flat markings the marking structure are advantageously in the form of a grid, preferably in the form of a grid with constant spatial frequency, arranged. As mentioned above, can the grid of the relief structure and the marking structure are the same Spatial frequency or, to create beating or moiré effects, easily have different spatial frequencies.

The flat marks are appropriate at least partially arranged on flanks of the relief elements, wherein a relief element and a flat marking disposed on at least one of its flanks together form a structural element. The flat marks point with advantage at least one colored area. Often it will be to form the flat markings with multiple colored surfaces, at least partially arranged on different flanks of the relief elements are, allowing the viewer from different viewing directions different color impressions wins.

In an advantageous embodiment of the invention contains the optical variable structure a plurality of structural elements (ie relief elements with flat marks arranged on at least one of its flanks), which represent a multicolored picture motif, its visual impression when changing the Viewing angle varies.

The Personalization marks can be letters, numbers or comprise a symbol code, such as a bar or matrix code. It can also have several constituents that are only under different Viewing angles are recognizable. For example, the customization flag represent a digit, depending on the viewing angles in a different color appears, or it can be two or more different symbols included, each recognizable from different directions are.

The Relief structure and the marking structure can be on a single or multi-layered Substrate, or on a substrate that is single or multi-layered coated, printed, glued, laminated or laminated.

The substrate and / or the surface of the security element can also have further, in particular machine-readable, security features in order to further increase the security against counterfeiting hen.

In A further development of the invention are the marking structure and the relief structure with one or more further layers combined, which is visually recognizable when viewed vertically Pattern or picture.

The raised relief elements of the relief structure can also be tactile with advantage be formed detectable. The height of this tactile marker above the surface can by choosing the laser parameters, the substrate material and Relative speed of laser beam and substrate during laser marking be varied in a wide context. Typically, a height is between 30 μm and about 100 μm selected.

The Relief structure may in particular a plurality of non-linear relief elements contain, wherein advantageously at least part of the non-linear relief elements essentially the shape of a tetrahedron, a sphere section, a truncated pyramid, a truncated cone, a cylindrical section, a torus section, an oval, a drop or a pyramid having.

Around To compensate for variations in register, the relief structure can be divided into subregions be divided, in which different partial relief structures are arranged. In particular, you can the partial relief structures each have a grid of the same screen ruling form and the grid of partial relief structures in at least two adjacent partial areas by a fraction of the grid width, in particular by about one third of the screen width, staggered be.

The Invention contains furthermore a data carrier, in particular a document of value such as a banknote, identity card or the like, with a security element of the above-described Art.

Further embodiments as well as advantages of the invention are described below with reference to FIGS explained. For better clarity, the figures refer to a scale and proportionally true representation omitted.

It demonstrate:

1 a schematic representation of a banknote with a security element according to an embodiment of the invention,

2 a section along the line II-II of 1 .

3 a section only of the relief structure of the security element of 1 in supervision,

4 a section only of the marking structure of the security element of 1 in supervision,

5 the combination of the relief structure of 3 and the marking structure of 4 .

6 a plan view of a security element according to an embodiment of the invention in a schematic representation,

7 a representation like in 5 for a security element according to a further exemplary embodiment of the invention,

8th a detail of only the marking structure of a security element according to a further embodiment of the invention in supervision,

9 a section only of the relief structure of the security element of 8th .

10 the combination of the marking structure of the 8th and the relief structure of 9 .

11 in (a) and (b) are schematic plan views of the basic grid of security elements according to further embodiments of the invention,

12 a schematic plan view of the basic grid of another security element according to the invention,

13 a security element according to yet another embodiment of the invention, wherein (a) shows the image impression when viewed perpendicularly (b), and (c) represents the image impression when viewed from an oblique angle (d), and

14 an evolution of the security element of 12 ,

The invention will now be explained using the example of a banknote. 1 shows a banknote 10 with a security element according to the invention 12 that in the print image area 14 the banknote is arranged. The security element 12 contains an optically variable structure that presents different information to the viewer under different viewing directions, thus exhibiting a tilting effect. Such security elements are often used in banknotes and other monetary documents, since the tilting effect can be easily visually recognized and checked by the viewer, but he just because of the directional dependence of the visual impression with today's copy machines that reflect the optically variable structure from only one line of sight, can not be reproduced.

The optically variable structure of the security element 12 also has an individualization flag, which is characteristic of the individual data carrier. For example, banknotes can be all or part of the serial number; for identity documents, the individualization can contain personal data or a portrait. In order to be able to integrate this individualization code in the optically variable structure, this is, as explained in detail below, generated in at least one of the steps for producing the optically variable structure with a non-contact method or a printing method without fixed printing form.

First, the basic structure of the optically variable structure of the security element 12 with reference to the 2 to 5 explained in more detail, wherein 2 a schematic sectional view taken along the line II-II of 1 shows. 3 shows a section of only the relief structure of the security element 12 in supervision, 4 a section only of the marking structure of the security element 12 in supervision and 5 shows the combination of the relief structure of 3 with the marking structure of 4 ,

As best in the presentation of 2 to recognize, has the optically variable structure 20 a plurality of raised relief elements 22 on, for example, by embossing the banknote 10 can be generated. If the banknote is mechanically deformed with an embossing tool, the underside of the banknote shows corresponding negative deformations, which, however, are not essential in the context of the present invention and are therefore not shown in the figures. If the relief elements are produced in a different way, for example by the action of a laser beam on the substrate material, then as a rule no corresponding deformations occur on the banknote backside.

The optically variable structure 20 further includes a marker structure having a plurality of flat marks 24 . 26 on different flanks of the relief elements 22 are arranged and give the security element so depending on the viewing direction different appearance.

The 3 and 4 show for illustrative purposes a section of the relief structure and the marking structure in a plan view, wherein the dotted-line square grid serves only for a clearer representation. Both the relief elements 22 as well as the flat marks 24 . 26 are arranged in a grid with a constant spatial frequency whose horizontal and vertical grid width are given by values x and y. In the exemplary embodiment, a square grid with x = y is shown.

As in 4 To recognize, is the spatial frequency of the marking structure on an imaginary reference point 28 in the center of each grid square. The flat markings 24 . 26 itself can take different positions within the grid squares to come to lie on different flanks of the relief elements. If, for example, the marking structure of the 4 with the relief structure of 3 combined, so come the flat marks 24 and 26 on opposite flanks of the relief elements 22 to lie, as in the 2 and 5 shown. In each case a relief element 22 forms together with the arranged on one of its flanks flat mark 24 or 26 a structural element 32 , wherein the structural elements 32 as the smallest units, the pixels form the rasterized information represented overall by the optically variable structure.

When viewed from a first viewing direction 30 ( 2 ) determine especially the markings 24 the picture impression, while the markings 26 hardly or not at all visible. By contrast, when looking at the structure from an opposing viewing direction, it is the markings that predominate 26 the picture impression, while the markings 24 hardly or not at all contribute. By suitable arrangement of the markings 24 and 26 can be an individualization indicator with tilt effect in the optically variable structure 20 of the security element 12 to get integrated.

Hereinafter, some concrete embodiments will be described, wherein first on the basis of 2 to 10 Embodiments are described in which the relief structure and the marking structure are generated in separate steps.

In a first embodiment, now mainly with reference to the representation of 2 and 6 is explained in more detail, the individual information is introduced by color change or color removal in relief structures, which were embossed with or without flat color layers in substrates.

This is done first on a substrate 40 a laser absorbing, for example, black color layer 42 imprinted, which can be removed or modified locally in a later step by the action of laser radiation, so that at the location of the laser application, a local color change.

Then relief structures are embossed in the printed substrate, in the exemplary embodiment in the form of a regular nub relief 22 , as in 2 and 3 shown. The printed and embossed substrate is then exposed to generate the flat markings with laser radiation according to a predetermined bitmap template, wherein the reference points of the dot screen template the same screen widths x and y as the knob relief 22 having.

In the simplest case, the laser coating causes the black color layer 42 locally worn, leaving at the marked places 22 . 24 the white background layer of the substrate emerges as in 2 shown. Under the laser absorbing paint layer 42 it is also possible to arrange a different-colored, nonabsorbing ink layer which is exposed locally by the laser application. In further embodiments, by the laser radiation without ablation a local color change in the ink layer 42 be induced. For example, the color layer may comprise a color mixture with a mixture component absorbing the laser radiation and a mixture component transparent to the laser radiation, wherein the absorbing mixture component bleaches, vaporizes, changes in its reflection properties under the action of the laser radiation, or changes into a material having other optical properties by a chemical reaction Properties can be converted so that visually recognizable flat marks arise.

It will be appreciated that the flat markings of the dot screen pattern are not all located at the reference point to represent information. Rather, as in 6 shown a first subgroup 46 the flat marks from the reference point are shifted by (+ x / 4, + y / 4), ie to the upper right, while a second subgroup 48 the flat marks from the reference point by (-x / 4, -y / 4), that is shifted to the lower left. The first and second subgroups of flat marks thus come on opposite flanks of the relief elements 22 to lie. The clearer presentation is in 6 the one with the black color layer 42 printed relief elements 22 unfolded while the flat marks 22 . 24 , in which the color coating is removed, and thus appear bright to the viewer, in the schematic representation of 6 are shown filled.

The first and second subgroups of flat marks 46 . 48 together form the information that is written to the optically variable structure by the laser as an individual identifier. In the embodiment of 6 form the two subgroups 46 . 48 together the number "5". Viewing from direction 50 The viewer looks especially at the bright markings 26 the first subgroup 46 while the marks 24 the second subgroup 48 on the side facing away from the viewer flank of the relief elements 22 lie. The numeral "5" therefore appears dark against a light background from this direction.

Looking from direction 52 on the other hand, the viewer looks at the bright markings 24 the second subgroup 48 while the marks 26 the first subgroup 46 on the side facing away from the viewer flank of the relief elements 22 lie, giving the numeral "5" out of direction 52 bright against a dark background appears. This contrast change occurs noticeably when tilting the security element. It is understood that depending on the shape of the relief elements 22 and the relative location of the marks 24 . 26 to the reference point 28 Other excellent viewing directions can be chosen.

Since the registration of a printing press must be expected that the lasered markings 24 . 26 also on the middle of the pimples 22 and in the valley between the pimples 22 can land and so no visible tilting effect, several similar fields can be created with relief structures in which the lasered dot grid is shifted by, for example, 1/3 of the screen widths. Equally, the pre-embossed knob pattern could also have these shifts in different fields.

The attachment of the flat marking 24 . 26 in the right place can be supported by the substrate 40 matching the relief structure 22 is coated so that, for example, certain places accept color, others not. If the marking is carried out with the aid of laser markers, the coating can advantageously be arranged such that certain points absorb laser radiation at a certain parameter set (for example from energy and / or wavelength and / or pulse length) and thus undergo a color change, but others only other parameter set.

Possible register problems can also be reduced by determining the position of the given grid by means of suitable metrological measures. For this purpose, for example, registration marks can be introduced with the relief-giving operation, which then before the application of the flat markings 24 . 26 can be read by suitable sensors, or it can be used industrial image processing to determine the location of the given relief 22 to investigate. Since non-contact and / or digital printing methods can work without fixed original, not only the content but also the position of the flat marking can be determined shortly before the application and thus to the actual position of the reli efs be adapted.

In the same way, the information to be applied can be based on data that is only available during the transport of the substrate 40 be read from this, and then applied in accordance with this information. Thus, for example, the serial number of a banknote can be read before the laser and then the final digit as information in the nubs 22 be lasered. The same applies, for example, for personalization data of ID documents that are first read and then z. B. be partially incorporated into a tilted image.

The Information can also arise from the fact that the lasered points different size or Form or contracted to lines. she can for example, by color removal, color lightening or a change in the Color impression arise, with all these variants in the present Description be subsumed under the term "color change".

At The place of lasering can also be the ink-jet process or another Digital printing processes that operate with so little pressure that the relief structures are not destroyed become. Normally, this makes dark structures appear bright Substrate with embossing generated.

The Sequence of steps can also be reversed. typically, However, the order described is preferred because then the individualization takes place as the last print.

The relief elements 22 Can also be attached to two or more different places with markings 24 . 26 be provided, as in the embodiment of 7 shown. In this case, depending on the perspective different pictures. For example, a first symbol, such as a digit, may consist of landmarks 24 to be assembled, the lower left of the relief elements 22 appear. A second symbol, such as a letter, becomes a marker 26 composed, the top right of the relief elements 22 appear. Depending on the viewing angle, the first or second symbol is then perceived.

The The procedure for a stroke relief, ie a relief structure with linear relief elements, is analogous: In the pre-printed color a line pattern is coined, the has parallel flanks pointing in opposite directions. The flat marks are then inserted so that dashes arise, which land on the flanks. Different information can For example, be represented by the line grid around half the distance of the pre-embossed Reliefrasters is moved.

The preprinted ink can also be made as screen printing ink, contains the feature or effect pigments. It is essential for the present Design only that this color edit using the laser leaves. In this way, the for Tilting necessary resolution be achieved, even if for the pressure sieves with large mesh size have to be used around the higher one Pigment size calculation to wear.

Another possibility for introducing the individual information into the optically variable structure is to introduce the relief structures into contactlessly already provided with flat mark substrates, as now with reference to the 8th to 10 described.

First, in these embodiments, a substrate at regular intervals of a certain spatial frequency with flat marks, for example in the form of different colored circles 60 provided, as in 8th shown. For this purpose, all conventional printing methods of suitable resolution can be used.

Then, in the substrate by exposure to laser radiation, a relief structure with raised relief elements 62 . 64 generated as in 9 shown. In the exemplary embodiment, the grid widths x, y of the relief structure are selected to be identical to the grid widths x, y of the marking structure. The laser parameters for generating the relief structure are matched to the composition and the properties of the substrate, wherein for details of the known methods on the documents DE 102 47 591 A1 or DE 32 13 315 A1 is referenced. In addition, the laser parameters and the properties of the inks used for the flat markings are coordinated so that the inks used do not or only slightly absorb the laser radiation, so that they are not or only slightly changed or removed by the laser radiation.

In order to be able to display information, the relief structure in this exemplary embodiment contains a first and a second subgroup of relief elements 62 respectively. 64 , which are offset from each other by half the grid width. Depending on which of the colored circles 60 where on the relief elements 62 . 64 land, arise for the viewer from different viewing directions different color impressions, as based on 10 illustrated. Similar to the embodiment of the 3 to 5 can be the two subgroups of the relief elements 62 . 64 represent the shape of the desired individualization identifier, for example a number, a letter or another symbol. The excerpts of the 8th to 10 For example, they showed part of an optically color variable Representation of a number "5".

In this embodiment as well, it must be expected with normal registration using a printing press that the printed dots 60 also on the middle of the pimples 64 . 66 and land in the valley between the pimples and so no visible tipping effect arises. Therefore, a plurality of identical or similar fields can be created in which the lasered knob pattern, for example, each shifted by 1/3 of the screen widths in different directions. The preprinted dot matrix could be just as well 60 have these shifts in different fields.

The inscribed individual information can also arise because the lasered knobs, for example, have different size or shape or z. For example, to lines or "worms." The pre-printed dots 60 can also be provided with nubs at two or more different locations, so that different pictures are created depending on the viewing angle. So z. For example, a number may be composed of pimples, which appear below the dots in the bottom left corner, another one made of pimples, which appear at the top right. Depending on the angle of view, one or the other number is then perceived.

The The procedure for a stroke relief is similar again: Here is in the preprinted Draw a bar pattern palpable introduced, which has parallel flanks, which in opposite Show directions. The flat marks are then on the Flanks of this relief. Different information is displayed by the relief z. B. by half the distance of the preprinted line grid is moved.

The individual information can be generated in further embodiments of the invention in the form of a color or relief change to existing tilt images. In this case, first of all a conventional tilt image is produced according to the prior art and the individualization identifier is then determined by a contactless and / or a digital method in the form of an information-containing marking structure (such as in US Pat 2 to 7 or in the form of an informative relief structure (such as in 8th to 10 ) generated. This creates additional information within the specified tilting image that generates its own tilting effect.

Basically the inscribed, in particular lasered information also here by color change (Color removal, lightening or a change in the color impression) arise. The information can also arise because of that, that others Shapes are lasered as dots or dashes or different Sizes or Line weights used become.

A Variant of the invention arises when in front of the information-leading pressure passages one or more further layers are pre-printed. Then can either changed this layer be and thereby overhead layers are influenced or it can be exposed, depending on which of the layers is absorbent. If there are more layers underneath, they can be exposed. One of the layers can also be a feature color contained, only with technical aids seen or detected can be affected and exposed by the lasering.

In the other, now with reference to the 11 to 14 described embodiments, the relief structure and the marking structure by means of the same non-contact method, in particular by means of laser application generated, so that registration problems are inherently avoided. The individual information can be represented by the relief structure or the marking structure.

at first embodiments this variant of the invention is by applying coated Substrates each produced a relief structure in the substrate. The coating is chosen so that by the laser radiation in the same operation a color change (Color removal, lightening, bleaching) can be generated.

In the coated substrate can first the relief structures and then the flat marks or be introduced vice versa, depending on how it is procedurally advantageous appears. In most cases, it will be, the flat To bring in markings first. The arrangement of the two shares At the resulting tilting image can with the above described Figures and examples match, so that the flat markings consist of points that point to the Flanks of relief-forming pimples appear.

Of the Information content can either be in the arrangement of the flat marks or lie in the arrangement of the relief elements. Also in this variant of the invention Is it possible, different information visible from different angles too Make the flat marks for each different piece of information to come to rest on different parts of the relief. Also can effect colors be used as a substrate.

The basic grid can be aligned horizontally and vertically, as in 11 (a) shown in which the reference numeral 70 the relief elements and the reference number 72 denotes the flat marks. The grid width can be, for example, x = y = 0.5 mm. For the designs of the 11 (a) the pattern must be tilted "over corner" to view the different states, as by the arrows 74 indicated. If the pattern is to be tilted vertically from top to bottom, as the viewer might involuntarily say, it is an advantage to arrange the basic grid rotated by 45 °, as in 11 (b) shown. The arrangement of the information "on the corner", ie on the diagonal, has the advantage that more space is available for the information to be displayed.

Of course, there are other regular arrangements of the relief elements 70 or the flat markings 72 possible, in particular those in which the grid is stretched or compressed in one of the two main directions.

It may also be advantageous in the pre-printed substrate through fine textures or slightly different colors a graphic, to bring in a picture or a pattern that is visible in the top view is and the eye of the beholder of the hidden in the tilting image Information distracts. Only when tilting is then introduced Individualization information clearly.

There the creation of the relief elements by means of laser with a distance As the color goes along, the relief element expands the brightened Job. It can Also excipients are used in the substrate, the relief formation support; in this case will be for it A lower energy can be used, resulting in a less extensive color removal leads, so that for the flat marking area used a larger proportion obtained on the entire color removal and the information contained in the flat mark better visible becomes.

The height, the extent and the brightness of the relief elements 70 and the extent and brightness of the flat marks 72 can also be varied so that a raster image is created in the manner of an autotypic raster (ie equal spacing of the raster points for different point sizes). In this way, the observer in supervision will only perceive the raster image, but when tilting, there will be further information.

Also with another, with respect to 12 explained embodiment can be achieved that the inscribed individual information in supervision initially does not appear or difficult to see. For this purpose, the laser parameters are chosen so that the relief structure 70 and the flat marking structure in the coated substrate have the same or at least a similar gray value. Then be in certain areas 76 the arrangement of the relief elements 70 and the flat markings 72 interchanged. At an oblique angle, information can be seen that, depending on the angle of view and light, appears bright on a dark background or dark on a light background.

The latter two approaches can also be combined with each other, as now with reference to 13 explained. In the portrait shown there 80 the relief elements and the flat markings are each arranged in a constant grid. The different impression of brightness arises only through a variation of height, extent and brightness of the relief elements and of the extent and brightness of the flat markings. In the area 82 whose outline represents individual information, in the embodiment the figure "5", the arrangement of the relief elements and the flat markings is interchanged, as in 12 shown.

Looking at the portrait 80 from the vertical viewing direction 84 ( 13 (b) ), this interchanging can not be recognized, since the exchanged and unexchanged arrangements produce the same brightness impression from this viewing direction. The image impression thus corresponds to the representation of 13 (a) , Will the portrait 80 on the other hand tilted and from an oblique angle 86 considered ( 13 (d) ), so the area rises 82 depending on the direction of observation bright or dark from its surroundings and the registered individual information is recognizable as in 13 (c) shown schematically.

The described embodiments can be extended such that the optically variable structure contains additional information which can be recognized, for example, in the horizontal tilting direction. 14 shows an extension of the embodiment of 12 , So a relief structure with Re elements running 70 and a marking structure with flat marks 72 , wherein the arrangement of the relief elements 70 and the flat marks 72 in certain areas 76 is reversed. In the embodiment of the 14 are perpendicular to the line connecting the relief elements and the flat markings additional markings 78 provided that may contain further information.

This further information lies outside the flanks of the relief elements 70 and is therefore easy to see even when viewed vertically. The further information can therefore be used to display image content, especially in the supervision that the eye of the beholder of the actual Kip distract p information first.

In other embodiments, the additional markings 78 be appropriate only in certain places or reinforced in certain places. It is also possible the additional marks 78 and the tilt picture 70 . 72 to be arranged so that they complement each other.

The additional marks 78 can also be used to lighten the overall appearance of a security element or to further match the gray values of flat markings and relief elements. For this purpose, size and color removal of these additional marks can be adjusted accordingly.

The contrast arising when tilting can be improved by adjusting the area ratio of the light markings (flat and relief) to the brightness impression of the total area. For a technical description and comparison measurement, the brightness is described in grayscale. The so-called simple contrast is thus formed from the ratio of gray level of the bright points (G _h ) to the middle gray level of the total area (G _m ): K = G H /G m ,

As you can see now this ratio is better, the darker the overall impression of the surface and thus the smaller G _m.

The same applies to the so-called Weber contrast, which is due to K w = (G H - G m )/G m is given, and in the case of the gray values present here also for the modulation K M = (G H - G m )/(G H + G m ).

It So is advantageous, the individual marking points in one distribute lower spatial frequency, since thereby the impression of brightness the total area is lowered. Still, when optimizing the contrast, too Care should be taken that when tilting for the brighter image components a sufficient area coverage is necessary and that the picture context is too far apart Pixels is not lost. To meet these requirements To carry, preferred screen widths are between about 0.4 mm and 1.2 mm, the range between 0.5 mm and 1 mm being particularly preferred is.

In the same way, the overall brightness can be lowered by using the darkest possible shade with the highest possible saturation for the background color. It is particularly advantageous to use the method of stitch printing used in security printing, which allows a good saturation due to the ho hen layer thicknesses. Since it is problematic with conventionally produced intaglio printing plates to print surfaces, methods are preferred which allow a small-scale structuring even of deeper surfaces and thus produce defined inking patterns, as for example in the documents DE 100 44 711 A1 or DE 198 45 440 A1 described, the disclosure of which is included in the present application in this respect.

Instead of to coat the substrate with a laser-sensitive layer, can also substrates are used, which are on the laser application with blackening or coloring react. Also in this variant of the invention is the order the production of the two parts Relief and flat marking free. The arrangement of the two parts, for example, again the correspond to the illustrations shown above.

the Substrate can Additives that assist in the production of Relief. simultaneously can with big Advantage dyes or pigments are used, which at different Power or energy density of the laser a different Color change, or those that depend on it from other laser parameters, such as wavelength or pulse duration, etc. do.

Advantageous are also substrates that already without special additives with different color impressions different laser power or energy densities react. For example, you can for plastics be used in the high power or energy density Relief structures are introduced by the fact that in the substrate Expansion of gases bubbles form. These generally have a whitish color due to light scattering Color impression. A lower energy running flat mark results contrast, a color change to darker shades. As substrates are available here especially PVC, polycarbonate or PET variants.

Also the combination of the two process steps described above is possible. For example, in one with for the laser radiation absorbing pigments and / or dyes coated substrate first a flat mark can be lasered, which removes the color becomes. The flat mark contains also the location of the relief structure. Then the relief structure is in The exposed substrate is lasered and produces there again a blackening or a color change.

Claims (36)

Method for producing a security element with an optically variable structure, which is an individualization mark contains with the process steps: a) Providing a substrate with a marking structure having a plurality of flat marks; b) Providing the substrate with a relief structure having a plurality raised relief elements, the marking structure and the relief structure are combined so that from different viewing directions different information is visible, and the Individualization indicator in at least one of the steps a) or b) with a non-contact Process or a printing process without a fixed printing form generated becomes. Method according to claim 1, characterized in that that the marking structure and the relief structure with the same Procedures are generated in one step. Method according to claim 1, characterized in that that the marking structure and the relief structure in separate Steps are created, with the marking structure before or after the relief structure can be generated. Method according to at least one of claims 1 to 3, characterized in that the relief structure in the substrate embossed becomes. Method according to claim 4, characterized in that that the relief structure is produced with a stamping tool. Method according to claim 4, characterized in that that the relief structure is produced in intaglio printing. Method according to at least one of claims 1 to 3, characterized in that the substrate by the action of a Laser beam is provided with the relief structure. Method according to at least one of claims 1 to 7, characterized in that the relief structure in the form of a Rasters, preferably a grid with constant spatial frequency, is trained. Method according to at least one of claims 1 to 8, characterized in that the substrate by the action of a Laser beam is provided with the marking structure. Method according to at least one of claims 1 to 8, characterized in that the marking structure on the Substrate is printed. Method according to claim 10, characterized in that that the marking structure in the ink-jet process or with a applied with low pressure digital printing process to the substrate becomes. Method according to claim 10, characterized in that that the marking structure in planographic printing, such as in the offset method, in high pressure, such as letterpress or flexographic printing, in screen printing or a thermographic process such as in the thermal transfer process, is generated. Method according to at least one of claims 1 to 12, characterized in that the marking structure in shape a grid, preferably a grid with a constant spatial frequency formed becomes. Method according to at least one of claims 1 to 13, characterized in that the individualization indicator Letters, numbers or a symbol code, such as a dash or matrix code. Method according to at least one of claims 1 to 14, characterized in that the substrate and / or the surface of the Security elements contains additional safety substances that in at least one of the steps a) or b) activated, exposed, covered, partially destroyed or removed. Security element with an optically variable structure, the one marking structure with a plurality of flat marks and a relief structure having a plurality of raised relief elements contains whereby the marking structure and the relief structure are combined in this way are different from different viewing directions Information is visible, characterized in that the marking structure and / or provided the relief structure with an individualization indicator is that with a non-contact Process or a printing process without a fixed printing form generated is. Security element according to claim 16, characterized that the relief elements of the relief structure in the form of a grid, preferably a grid with a constant spatial frequency, arranged are. A security element according to claim 16 or 17, characterized in that the flat markings of the marking structure in the form of a Rasters, preferably a grid with a constant spatial frequency, are arranged. Security element according to claim 17 and 18, characterized characterized in that the grid of the relief structure and the marking structure have the same spatial frequency. Security element according to claim 17 and 18, characterized characterized in that the relief structure and the marking structure slightly different to produce beat or moiré effects Have spatial frequencies. Security element according to at least one of claims 16 to 20, characterized in that the flat marks at least partially arranged on flanks of the relief elements, wherein a relief element and a arranged on at least one of its flanks flat mark together to form a structural element. Security element according to Claim 21, characterized the flat markings have at least one colored surface. Security element according to at least one of claims 21 to 22, characterized in that the flat markings more colored surfaces at least partially on different flanks the relief elements are arranged. Security element according to at least one of claims 21 to 23, characterized in that the optically variable structure a Contains a plurality of structural elements that form a multicolored image motif represent its visual impression when changing the viewing angle varied. Security element according to at least one of claims 16 to 24, characterized in that the individualization identifier Letters, numbers or a symbol code, such as a dash or matrix code. Security element according to at least one of claims 16 to 25, characterized in that the relief structure and the marking structure on a single or multilayer substrate are arranged. Security element according to at least one of claims 16 to 26, characterized in that the relief structure and the marking structure on are arranged on a substrate which is coated on one or more layers, printed, glued, laminated or laminated. Security element according to at least one of claims 16 to 27, characterized in that the substrate and / or the surface of the Security elements further, especially machine-readable security features having. Security element according to at least one of claims 16 to 28, characterized in that the marking structure and the Relief struc ture combined with one or more other layers which are a visually recognizable pattern when viewed vertically or picture. Security element according to at least one of claims 16 to 29, characterized in that the relief elements tactile detectable are formed. Security element according to at least one of claims 16 to 30, characterized in that the relief structure has a plurality non-linear relief elements contains. Security element according to at least one of claims 16 to 31, characterized in that at least a part of the non-linear relief elements essentially the shape of a tetrahedron, a sphere section, a truncated pyramid, a truncated cone, a cylindrical section, a torus section, an oval, a drop or a pyramid having. Security element according to at least one of claims 16 to 32, characterized in that the relief structure in partial areas is divided, arranged in which different partial relief structures are. Security element according to claim 33, characterized in that that the partial relief structures each have a grid of the same screen ruling form and the grid of partial relief structures in at least two together bordering areas by a fraction of the grid, in particular arranged offset by about one third of the grid. disk, in particular value document such as banknote, identity card or the like, with a security element according to one of claims 1 to 34th Use of a security element after at least one of the claims 1 to 34 or a data carrier according to claim 35 for counterfeiting of goods of any kind.