HK1059418B - Data carrier, method for the production thereof and gravure printing plate - Google Patents

Description

Data carrier, method for producing the same and intaglio printing plate

Technical Field

The invention relates to a data carrier having a security element (security element) with a plain-embossed security element formed by intaglio printing, to a method for the production thereof, and to a printing plate for the plain-embossed security element.

Background

The data carrier according to the invention is a security or value document, for example: banknotes, identification cards, passports, cheques, shares, certificates, stamps, tickets, etc., as well as labels, seals, packaging or other product protectors. The simplified names "data carrier" and "security document or value document" in the following generally include documents of the type mentioned.

Documents whose market value or use value far exceeds the value of the material must be distinguishable, by suitable measures, from counterfeits and counterfeits. They therefore carry special security elements which cannot be imitated or cannot be imitated and counterfeited with great effort.

In the past, it has been demonstrated that: in particular, those security elements which are authentic and can be produced with great effort without the need for tools to be identified by an observer are useful. These security elements are, for example: watermarks in data carriers, or basic motifs (motifs) produced by intaglio printing, are only possible in paper-making processes, these security elements being characterized by a characteristic tactile impression which cannot be imitated by copiers.

For gravure printing, it is unusual: the printed areas (i.e., ink transfer areas) of the printing plate appear as depressions on the surface of the plate. These recesses are formed by a suitable engraving tool or by etching. Prior to the actual printing operation, ink is applied to the cliche plate and excess ink is removed from the cliche plate surface by a stripper blade or wiping roller so that the ink remains only in the depressions. The substrate (usually paper) is then pressed against the clich e and removed, and the ink adheres to the substrate surface and forms a printed image thereon. If clear ink is used, the ink thickness determines the hue.

In the gravure printing technique, there is a difference between rotogravure printing and intaglio printing or line gravure printing. In rotogravure printing, the printing plates are produced, for example, by electron beams, laser beams or engraving knives. Rotogravure printing is characterized by the fact that different grey levels or colour values of the printed image are obtained by means of intaglio ink cells of different densities, sizes and/or depths regularly arranged in the printing plate.

In contrast, in gravure printing, linear depressions are formed on a printing plate to form a printed image. In mechanically manufactured printing plates for gravure printing, since a tapered engraving tool is generally used, a wider line is formed by increasing the depth of the engraving. Furthermore, the ink receptivity of the engraved lines and the opacity of the corresponding printed lines increases with increasing engraving depth. During the etching of intaglio printing plates, the non-printing areas of the printing plates are covered with a chemically inert lacquer. Subsequent etching may create recesses for receiving ink in the exposed plate surface. The depth of the engraved lines depends in particular on the etching time and the line width.

The high load pressure of gravure printing subjects the substrate material to additional imprinting, causing the imprinting to stand out on the back side of the substrate. If a non-inked intaglio printing plate is used, the substrate used is subjected to so-called embossing, which gives the data carrier a typical surface relief.

Intaglio printing, in particular steel intaglio printing, provides a characteristic printed image or embossed image. These images are easily recognized by laymen and cannot be reproduced by other conventional printing methods. Data carriers printed by intaglio printing are given a printed image by embossing and inking if the engraving in the printing plate is sufficiently deep; and applying ink on the printed image may form a relief that is perceived with tactile feel. Steel intaglio printing is therefore preferably used for printing data carriers, in particular bonds and securities (e.g. banknotes, stocks, bonds, certificates, vouchers, etc.), which documents must comply with high anti-counterfeiting standards.

WO97/48555 discloses a method for manufacturing intaglio printing plates in a reproducible manner by machine. The lines of the original lines are detected and the surface of each line is accurately determined. An engraving tool, such as a rotary nicking tool or a laser beam, is first used to engrave the outer contour of this surface to clearly define the surface. The defined area of the surface is then finished by means of the same or another engraving tool, so that all lines are engraved exactly according to the original line. Depending on the form and manipulation of the engraving tool, a substantially uneven pattern of ink traps for the ink appears on the bottom of the finished surface.

It is also proposed to use intaglio printing plates for the embossing of the elements. It is known in the art to perform a primordial imprint in a metal layer. However, the known embossing of the master is a very simple embodiment, which has only one predetermined embossing height or depth. That is, imprinting is performed with a printing plate having only one-step finished engraved lines of a fixed depth. Embossed areas of different sculpture depths (e.g. lines of different depths) are always separated by areas that are not engraved. Such an imprint is only visually discernible at certain oblique viewing angles, and therefore such security features are often not perceptible to a viewer and are more likely to miss attempts at counterfeiting. Typically, such impressions are not as deep as the impression to the viewer.

Disclosure of Invention

The technical problem underlying the present invention is to increase the security of a data carrier by applying to the data carrier a more difficult to imitate, more complex security document which is easily visually perceptible and has an optically noticeable pattern.

This technical problem is solved by the independent claims. Further developments are the subject matter of the dependent claims.

The data carrier of the invention is characterized in that: the security document is at least visually detectable and has an imprint in the form of a half tone (halftone) plain imprint by inkless intaglio printing, at least in partial areas.

A halftone elementary embossing (halftone marking) is an elementary embossing with a plurality of different embossing heights or depths preferably touching each other smoothly. Preferably, the halftone elements are imprinted as a stereoscopic image of a three-dimensional original (e.g., a styling art or relief image). Alternatively, starting from a two-dimensional original, the image can also be converted into a three-dimensional original according to the respective properties (for example according to the colors present in the two-dimensional original, the halftone, the line width, etc.). In a next step, starting from the three-dimensional original to be reproduced as an impression, a halftone image particularly suitable for the knurling of printing plates is produced in which a certain engraving depth is given a certain grey value.

The darkest grey scale is preferably given to the areas that float most in the impression, and thus the depth of the sculpture is greatest; for areas with more depressions, lighter shades of gray are given, and thus the depth of the sculpture is smaller. When the halftone image is converted into an engraved image, a three-dimensional relief is formed on the engraved plate. The engraving tool may be directed to form a pattern having a continuous engraving depth. In particular, by reinforcing the edges of the basic pattern profile, a clear and sharp image can be obtained on the paper.

In a simple embodiment the original consists of alphanumeric characters and/or simple pattern elements constituting text or the like. The characters and/or elements have different relief heights, forming a "modulated" surface structure. The effect is even more enhanced if the size of the characters and/or elements also changes.

According to a preferred embodiment, an original is used, such as a portrait, which can be converted into a plurality of different intermediate tones or grey levels. The individual gray levels or groups of gray levels of this conversion are then made to have different depths of engraving, for example, the maximum depth of engraving is made black and the minimum depth of engraving is made white. That is, the nose of the portrait, which is usually the brightest portion in the original, must be represented in black at its highest point in the halftone image, with the engraving deeper at that location, so that the resulting impression is raised above the paper. Accordingly, all image portions in the portrait are converted to corresponding gray values. The intermediate tone image converted into the depth of the sculpture is used to control the sculpture tool. The areas milled to different depths are directly adjacent. I.e. they are not separated by a zone located at the level of the printing plate. The depth of the engraving may be up to 300 microns and more, preferably up to 250 microns. As mentioned above, the engraving can basically also be performed with laser engraving.

The intaglio printing plate thus produced, having three-dimensional engraving reliefs, is finally used to imprint a data carrier in which the three-dimensional reliefs are again formed. This is essentially a printing process, but without transfer of ink. As is usual in intaglio printing, the data carrier is pressed into the depressions of the engraving plate and is permanently deformed, i.e. embossed, with a strong load pressure. The plate area with the largest depth of the sculpture generates the most obvious impression, namely the area with the largest deformation of the paper is formed; while the plate region with the smallest depth of the score forms the weakest impression. The paper in contact with the non-engraved areas of the printing plate or stamp is compressed uniformly with a large load pressure and compacted at least on the surface, so that these surface areas have an increased gloss after gravure printing.

It is also possible to selectively influence the gloss or the visual impression of the imprinted image sections. By means of the shape and the manner of manipulation of the engraving tool, it is possible to selectively form a relief pattern on the bottom of the engraving-finished surface, as was initially described in the description of the engraving method described in WO 97/48555. In the case of embossing, such unevennesses of the embossing plate affect the visual impression of the embossing area. In this way, an engraving tool with a large tip radius, a rounded geometry and a close proximity (e.g., about 10 microns) of a trimming track (clear path) may achieve a smooth engraving resulting in an impression that is smooth and tends to be somewhat reflective. On the other hand, if the tip radius of the selected engraving tool is small, with a geometry of point-cut edges and widely spaced trimming trajectories (e.g., in the range of about 50 microns), the resulting engraving is rough and significantly textured, resulting in a matte and diffusely scattered impression.

Another or additional way of varying the light scattering of the imprinted substrate is to change the trim direction in each local area during the engraving of the printing plate or the depressions in the printing plate. Engraving along a trimming trajectory that is linear but rotated, for example, by 90 ° produces visually distinguishable impressions with different light reflections. This method is also suitable for engraving with straight or curved trimming tracks, in contrast to spiral or concentric trimming tracks. These effects not only serve to emboss more attractive or noticeable patterns, but also to improve the security. This selectively applied engraving method can be used to superimpose structures on the embossed relief that are distinguishable only at certain viewing or reflection angles. On banknotes or other value documents, halftone pixel imprints forming a portrait may be superimposed, for example, with distinction by engraved substructures.

The imprinted image is three-dimensional and structurally complex. The surface occupied by the halftone pixel imprinting is not limited in any way. Preferably, the halftone pixel impression occupies 0.25cm²To a few cm²Of (2) is provided.

The halftone pixel imprints may form elements of any geometric shape, such as circles, triangles, squares or asymmetric outline structures, picture symbols, characters or other symbols. However, portrait images are particularly preferred because human perception is trained to recognize very small differences in the portrait, making the recognized value of such security elements particularly high. Multiple halftone pixel imprints may also be combined into any number and form.

To further improve the security of the security element, halftone pixel embossing may be combined with background print that is not formed by intaglio printing. The background print may be applied in a separate printing process prior to the manufacture of the intermediate tonemark. The background print is preferably made in solid form. The background print may be in the form of, for example, screen printing, lithography, indirect letterpress, letterpress or digital printing.

Any ink may be used to form the background print, but it is preferred to use an ink that has an additional anti-counterfeiting effect and a special effect that is difficult to imitate due to its physical properties. Particularly suitable inks are metallic inks, metal-pigment inks or interference layer-pigment inks, e.g. IRIONE from Merck^)。

Alternatively, the background imprint may also consist of a metal layer, which can be applied to the data carrier, for example, by hot embossing.

Preferably, the halftone pixel imprint is located entirely within the background print area. In a particular embodiment, the background print is constituted by an oval or circular metal print. This background print is then imprinted with a halftone element using gravure printing. Ideally, the halftone pixel impression is centered with respect to the background print to create the impression of a coin image.

Registration errors may occur because the background print and the halftone pixel imprint are applied to the substrate in different printing processes. Such alignment errors may be masked by a synthesis of correspondingly designed colored regions arranged in alignment with the halftone pixel imprint, so that the viewer has the impression of a precisely aligned halftone pixel imprint in the center of the background print. The halftone pixel imprints and one or more colored regions are preferably spaced apart unless the pixilated elements are selectively directed into the colored regions to form an optical bridge.

The colored area may be arranged to overlap the background print and may be shaped and colored such that the edges of the background print are "optically dissolved", i.e. to avoid smooth edge contours and to effectively hide or mask any deviations. For colored areas, a line pattern (e.g., a guilloche pattern) is particularly suitable, but solid marks can also be used, particularly with an ink layer thickness suitable to cover the background print or have the same hue as the background print.

According to a preferred embodiment, the colored region forms a border around the halftone pixel impression. The boundary may be any contour. However, an elliptical or circular profile is preferred and is provided at a fixed distance around the prime stamp, centering the prime stamp relative to the colored region. The boundary may be continuous or interrupted. Similarly, the boundary may be formed as a region, or as a pattern. Preferably, the border is in the form of a guilloche or a ring with an optically soluble inner edge (e.g. a centrally directed sawtooth). Also, the border may be composed of characters or have a geometric pattern, such as guilloches, combined with, for example, characters. The edges of the background print may also be designed in this way. If edge dissolution is achieved by periodic structures (e.g., serrations, guilloches, arcs, etc.) formed on both the colored areas and the edges of the background print, then the formation of a phase or frequency difference between the periodic structures of the background print and the colored areas can optimize "optical dissolution" or masking.

If both the halftone pixel print and the color print are formed by gravure printing, precise alignment between the halftone pixel print and the color print can be easily achieved. In this case, the intaglio printing plate can be provided with engravings for the halftone pixel imprinting and engravings for the colored areas in one process step. The high thickness of the intaglio-printed ink layers is particularly advantageous here because they can effectively cover any background print present.

This intaglio printing plate is preferably made by engraving with a rapidly rotating, tapered scale, as all other intaglio printing plates according to the present invention. The engraving tool can form depressions of selectively varying engraving depth in the surface of the printing plate, depending on the contour shape of the surface to be printed or primordially imprinted. If the engravings for the halftone pixel imprinting and the engravings for the colored areas are adjacent in some places, it is known from DE19845436a1 that it may be advantageous to provide separating edges in these border line areas to prevent ink from entering the areas of the halftone pixel imprinting or flowing further into the pixel imprinting.

Only the engraved portions forming the colored areas are filled with ink before the printing process. During printing, the substrate is pressed into the engraved areas of the printing plate with and without ink. In this way, ink is transferred from the inked engraved portion to the substrate. At the same time, the substrate is embossed as is usual in gravure printing. But in the non-inked areas of the intaglio printing plate the substrate is only embossed. No ink is transferred from the untreated, i.e. non-engraved, surface areas of the printing plate.

When printing or embossing the data carrier in the manner described above, correspondingly designed embossings of the data carrier are formed, depending on the form of the above-described engravings of the printing plate, with some of these embossed areas being inked. The dimensions of the ink layer areas (e.g. width and ink layer thickness) are determined by the depth and width of the engravings of the printing plate of the invention and the ink used in printing.

Typical gravure inks can be printed opaque, or to some extent transparent and translucent, depending on the ink layer thickness selected. Suitable layer thicknesses and an advantageous selection of the background color result in hues of different brightness and color saturation. If the ink layer thickness difference is large enough, the contrast can be easily seen by the human eye without additional tools. This presupposes normal lighting conditions and normal viewing distances.

In order to increase the stability of the data carrier, it is advantageous if the imprint produced on the front side of the security element can be filled with a coating (e.g. lacquer). The paint may contain characteristic substances (e.g. luminescent substances, etc.) or other special effect pigments (e.g. liquid crystal pigments). In addition, the paint may be matte or glossy. In addition, the protective lacquer layer also serves to increase the gloss effect and to protect the impression.

Data carriers with such complex security elements are characterized by an improved security against forgery as a result of the effect of a high contrast of light and shade produced by multi-step halftone pixel imprinting. The integration of the possibly also tactile intaglio printing of colours arranged in register with the halftone pixel imprints and overlapping with the background print may also increase the protection against counterfeiting and imitation.

Another way of increasing the security is to provide the basic pattern of the halftone pixel imprint several times on the data carrier, but each time in a different way. For example, the same basic pattern may be used for watermarking and/or classic colour intaglio printing. It is also possible to repeat the same basic pattern in the background print on the imprinted hologram using inks with varying fluorescence or optical properties, for example inks with interference layers or liquid crystal pigments, or using so-called latent images and combinations of the above.

The security element according to the invention can be used for a single data carrier or a substrate with a plurality of data carrier replicas.

Suitable substrate or data carrier materials are all substrate materials which can be used for gravure printing, for example: paper, plastic sheeting, paper or coated paper laminated to plastic sheeting, and multi-layer composites. The method of the invention is particularly suitable for printing data carriers which have to meet security standards, such as security documents and value documents, for example banknotes, stocks, bonds, certificates, vouchers and the like.

Drawings

Embodiments and advantages of the present invention will be further explained with reference to the accompanying drawings. Wherein:

FIG. 1 shows a front view of a banknote;

FIG. 2 shows a cross-section taken along line A-A in FIG. 1;

FIGS. 3-6 illustrate different embodiments of security elements of the present invention;

FIG. 7 shows a halftone image of the halftone pixel imprinting of the present invention;

FIG. 8 shows the engraved depth pattern of the intaglio printing plate of the present invention taken along the line A-A in FIG. 7;

FIG. 9 shows a data carrier according to a further embodiment of the invention;

FIG. 10 shows an enlarged detail of FIG. 9;

FIG. 11 shows a cross-section taken along line A-A in FIG. 9;

FIG. 12 shows a front view of a data carrier according to the invention;

fig. 13 shows the layout of the background print and the colored areas.

Detailed Description

Fig. 1 shows a schematic representation of a banknote 1 as a data carrier with a security element 2 according to the invention. The security element 2 according to the invention consists of a background print 4, a halftone pixel imprint 3 and a color region 5 arranged in register with the halftone pixel imprint 3. In order to increase the security of the banknote 1, the basic pattern of the halftone pixel 3 is repeatedly impressed several times on the banknote in different ways. In the example shown, the basic motif on the banknote 1 is a engraved-steel portrait 13 and a watermark 14.

In the example shown, the security element 2 according to the invention is in the form of a coin, wherein a halftone pixel imprint 3 is preferably provided on a metallic background imprint 4. The background print 4 overlaps a colour print 5, which may be of a plurality of colours and/or be a pattern, character, etc. In the example shown, the colored area 5 is shown as a solid border around the halftone pixel imprint 3, which in some areas is combined with the characters "XYZ" and "chapter". The colored areas 5 can be designed according to the engraved depth of the printing plate to form tactile edges on the printed image.

However, the colored regions may have other forms. For example, it may consist of a guilloche pattern. The colored area 5 may also be a color that is coordinated with the background print 4 such that the edges of the background print 4 "dissolve", i.e. hide, for the viewer.

In order to form the security element 2 according to the invention, in a first step, a background print 4 is produced on the data carrier. Preferably, the solid background print is made by screen printing using a gold or silver colored metallic pigment ink. Then, in one working step, halftone pixel imprints 3 and colored areas 5 are formed in the area of the background print 4 by means of gravure printing. I.e. the corresponding intaglio printing plate has engravings according to the coloured areas 5 and engravings according to the halftone pixel imprints 3. However, for the printing process, only the engraved areas where the colored areas 5 are formed are filled with ink. This results, as in conventional intaglio printing, in that the data carrier 1 is embossed and carries ink in the region of the colored areas 5 during the printing process. On the halftone pixel imprinting area, however, the data carrier is only imprinted. Since the load pressure on pressing the data carrier 1 into the engraved regions of the steel intaglio printing plate is high, the back side of the data carrier 1 also has visible impressions.

This state is shown in fig. 2. Fig. 2 shows a cross-section through a security element 2 according to the invention, taken along the line a-a. It can be seen that in the intaglio printing process the data carrier 1 or the background print 4 is embossed only in the area of the halftone pixel impressions 3. Since the background print 4 is applied to the data carrier 1 in a separate process step, alignment errors may occur between the background print 4 and the halftone pixel imprinting or color areas 5. For this reason, as shown in fig. 2, the colored area 5 is preferably arranged to overlap the background print 4 in order to conceal such alignment errors. It is also evident from fig. 2 that the left area of the background print 4 is covered much less by the colored area 5 than the right area. However, since the coloured areas 5 are arranged in register with the halftone pixel impression 3, the viewer perceives the halftone pixel impression to be in the centre of the area of the background print 4.

The optical effect of the three-dimensional relief of the halftone pixel imprint can be enhanced for the viewer by different light and shade effects, especially if a background print with metallic luster is used.

The method of accurately aligning the areas printed and embossed using gravure printing may be used to combine the basic patterns forming the printed and embossed portions. For example, trunks and branches may be nanoimprinted, while leaves or tops may be printed with ink. In text or other regularly arranged structures, a precisely aligned, linear arrangement of alternately printed and embossed symbol or picture elements is also possible.

Fig. 3 to 6 show front views of different embodiments of the security element 2. In fig. 3, the background print 4 has a ray-like lysing edge. The colored area 5 forms a solid circular border which is preferably printed concentrically with the background print 4 and whose inner edge dissolves in the form of a ray pointing to the center of the circle. The different frequencies of the rays superimposed on each other by the intaglio-printed background print and the coloured areas can optically mask the misalignment between the two prints.

The difference between fig. 4 and the example shown in fig. 3 is only that the border 5 does not cover the entire circumference of the radial edge of the background print 4, but only in a partial area.

Fig. 5 shows the principle of a further embodiment of the security element 2, in which at least a part of the halftone pixel imprint is drawn in register with the colored regions 5 and continues in the form of gaps in the colored regions 5. In this example, the schematically represented halftone pixel imprint consists of different hatched or hatched areas 6, 7, 8. The halftone pixel imprinted elements 7 form a fine line cross (hairlineacross) and as far as the colored areas 5. The embossed thin-line cross formed by the embossing elements 7 continues in the color border 5 in the form of gaps 9. Precise alignment between the stamping elements 7 and the gaps 9 is only possible in one process step, using a gravure printing plate to form the stamping and coloured boundaries 5 simultaneously. The counterfeit method in which the embossed areas 6, 7, 8 and the coloured areas 5 are formed independently of each other cannot achieve this alignment. This alignment offset is easily visually recognizable and therefore can be easily distinguished from a genuine document.

Fig. 6 shows another embodiment of the principle shown in fig. 5. In this example, the halftone pixel impression 3 represents a bird on a branch. The end of the branches that reaches the coloured border 5 is formed by the stamping element 7 and continues as a negative image or gap 9 in the printed area 5. The same is true for bird tail feathers. These feathers are also drawn as impression elements 7 to the colored area 5 and continue there in the form of gaps 9.

Fig. 7 shows a halftone image whose data may be used to make the intaglio printing plate of the present invention. The halftone image is formed from a three-dimensional original with darker gray levels in areas that float out more in the subsequent impression. The different gray levels of this halftone image have different depths of the sculpture and these data are sent to a milling machine, such as a CNC milling machine. The milling machine engraves the intaglio printing plate according to this information.

Fig. 8 shows the pattern of the groove depth taken along line a-a in fig. 7. The greatest depth of the score is in the nose tip region and neck fold region, which are shown as dark black areas in fig. 7. The engraved depth of all the halftone images located between these regions is small.

Fig. 9 schematically shows a banknote 1 as a data carrier of a further embodiment of a security element 2 according to the invention.

The security element 2 of the invention consists of a background print 4 in the form of an oval emblem, indicated with black dots, and a halftone pixel imprint 3 representing the number "6" added to, preferably, the center of the background print 4. The appearance of the background print 4 is preferably metallic, in particular gold or silver, in order to give the viewer the impression of a coin.

Fig. 10 shows an enlarged detail of the security element 2 shown in fig. 9, which shows the sectional line a-a and the lower part 1/3 of the number "6" located below this line.

In this example, the halftone pixel impression 3 is composed of three different impression levels 10, 11 and 12, which are realized in the impression image with staircase-like steps. Of course, more than three different degrees of embossing may be included. The white areas 10 shown in fig. 10 represent areas with no or little embossing; while the light grey area 11 represents a more embossed area than area 10; while the dark grey areas 12 are most embossed. Smoothing the data carrier material (e.g. paper) or background print produces a special gloss in the areas 10 which are not engraved or are engraved very slightly. On the other hand, regions 11 and 12 are matte.

Fig. 11 schematically shows a data carrier 1, wherein a cross-section of the background print 4 is taken along the line a-a shown in fig. 10. The different embossed areas 10, 11 and 12 can be clearly identified. The areas 10 are areas that are very smooth or have no imprint, and are formed by areas of the printing plate that have not been engraved during the imprinting process. The areas 11 and 12 represent medium or strongly embossed data carriers which are formed by means of medium or large engraved depth areas on the printing plate.

The level variation of the various degrees of embossing in one embossed image and the various combinations of these degrees result in complex security elements with high identification value.

Fig. 12 shows a data carrier 1 according to the invention, for example a banknote with a security element 2. The dotted background print 4 is formed by indirect relief printing as a shiny gold surface. The halftone pixel impressions 3 are formed simultaneously with the coloured areas 5 during the intaglio printing process, which ensures that the pixel impressions are aligned absolutely precisely with the coloured prints framing them. The colored areas 5 are fine guilloche structures that are difficult to reproduce. In order to better integrate the colored areas with their surroundings on the pattern and to soften the transition between the background print and the colored print, it is preferred that the colored print has an outer area that is "broken" and an inner area that comprises entangled fine lines in the positive image that only allows a small coverage. On the other hand, the central region has a high coverage and is spanned by thin lines, for example in a negative image.

The advantages and structure of this embodiment are illustrated in fig. 13, which fig. 13 is an exploded view showing the position of the coloured area 5 relative to the background print 4. The halftone pixel imprinting is not shown in this figure. The colored area 5 is disposed above the background print 4 such that the central area of the colored print 5 with a large coverage is above the edge of the background print 4. Since the background print 4 and the colour print 5 are printed by different printing methods and in mutually independent printing processes, there must be a misalignment, which can amount to several millimetres and which will greatly affect the appearance of the document with the security element. With the embodiment and structure shown in fig. 13, both types of print position errors can be compensated and effectively concealed.

Claims (39)

1. A data carrier (1) having a security element (2) which is at least visually detectable and which has an imprint at least in partial regions, characterized in that the imprint is a halftone pixel imprint (3) which is realized by means of inkless intaglio printing.

2. A data carrier as claimed in claim 1, characterized in that the halftone pixel imprint (3) represents an alphanumeric character, a pattern element or a halftone image.

3. A data carrier as claimed in claim 2, characterized in that the halftone pixel imprint (3) represents a portrait.

4. A data carrier as claimed in claim 1 or 2, characterized in that, in addition to the halftone pixel imprint (3), there is at least one color area (5) formed by intaglio printing in precise alignment, and the halftone pixel imprint (3) is spaced apart from the color area (5).

5. A data carrier as claimed in claim 4, characterized in that the distance between the halftone pixel imprint (3) and the one or more colored regions is at least 1 mm.

6. A data carrier as claimed in claim 5, characterized in that the distance between the halftone pixel imprint (3) and the one or more colored regions is at least 3 mm.

7. A data carrier as claimed in claim 1 or 2, characterized in that the halftone pixel imprint (7) and the colored region (5) are directly adjacent.

8. A data carrier as claimed in claim 7, characterized in that the halftone pixel imprint (7) adjoining the colored region (5) continues at least partially as a gap (9) into the colored region (5).

9. A data carrier as claimed in claim 4, characterized in that the halftone pixel imprint (3) is arranged centrally with respect to the color area (5).

10. A data carrier as claimed in claim 4, characterized in that the colored region (5) is formed around the border of the halftone pixel imprint (3).

11. A data carrier as claimed in claim 4, characterized in that the colored areas form a guilloche.

12. A data carrier as claimed in claim 1, characterized in that the halftone pixel imprint (3) is applied entirely on the background print (4) that is not produced by intaglio printing.

13. A data carrier as claimed in claim 12, characterized in that the background print (4) overlaps the colored area (5) at least in a partial area.

14. A data carrier as claimed in claim 12 or 13, characterized in that the background print (4) is printed by screen printing, offset printing or indirect letterpress printing.

15. A data carrier as claimed in claim 12 or 13, characterized in that the background print (4) is an effect layer.

16. The data carrier as claimed in claim 15, characterized in that the effect layer consists of a metal, a metallic ink or an ink containing a pigment of the interference layer.

17. A data carrier as claimed in claim 15, characterized in that the effect layer is bronze, gold or silver.

18. A data carrier as claimed in claim 12 or 13, characterized in that the background print (4) and the colored area (5) are mutually coordinated in color.

19. A data carrier as claimed in claim 18, characterized in that the background print (4) and the colored area (5) are of the same hue.

20. A data carrier as claimed in claim 12 or 13, characterized in that the colored areas (5) have an inner area with a large coverage and an inner and/or outer area with a small coverage; and the area with large coverage is arranged above the edge of the background print (4).

21. A data carrier as claimed in claim 1, characterized in that the basic pattern of the halftone pixel imprint (3) is formed on the data carrier several times and in different ways.

22. A data carrier as claimed in claim 1, characterized in that, in addition to the halftone pixel imprint (3), there is a watermark (14) and a further printed additional element; the watermark (14), the additional element and the halftone pixel imprint (3) have the same basic pattern.

23. A data carrier as claimed in claim 22, characterized in that the additional element (13) is printed by intaglio printing.

24. A data carrier as claimed in claim 1, characterized in that the partial regions of the halftone pixel imprint (3) have different roughness, so that the reflected light is visually distinguishable.

25. A data carrier as claimed in claim 1, characterized in that the halftone pixel imprint has, superimposed thereon, at least over part-areas, substructures which influence the visual appearance of the imprint and which have different orientations over the individual part-areas.

26. A method for producing a data carrier with a security element, comprising the following steps:

a) providing a data carrier material;

b) forming a gravure printing plate while engraving the three-dimensional relief into the plate surface; and

c) the data carrier material is subjected to a prime-embossing with the intaglio printing plate produced in step b).

27. The method of claim 26, wherein the three-dimensional relief represents an alphanumeric character, a pattern element, or a halftone image.

28. The method of claim 27, wherein the three-dimensional relief represents a portrait.

29. A method according to claim 26 or 27, characterized in that in step b), in addition to the three-dimensional relief, at least one further area is engraved into the plate surface, which area is exactly aligned with the three-dimensional relief and filled with ink; the ink is then transferred in step c) simultaneously with the halftone pixel imprinting from the other engraved area onto the data carrier material.

30. The method of claim 29, wherein the halftone pixel imprinting is centered with respect to the inked engraved regions.

31. The method of claim 29, wherein the colored region is formed as a border around the pixel imprint.

32. The method of claim 30, wherein the colored regions form a guilloche.

33. A method as claimed in claim 26, characterized in that after step a), background prints which are not formed by intaglio printing are applied to the data carrier material; and in step c) the prime stamp is applied completely on the background print area.

34. The method of claim 33, wherein the background print is printed using screen printing, indirect letterpress printing, or lithographic printing.

35. The method of claim 33, wherein the colored area overlaps the background print at least in a partial area.

36. The method of claim 33, wherein the colored regions are formed to have a central region with a large coverage and an inner region and/or an outer region with a small coverage; and the area of high coverage is disposed over the edge of the background print.

37. Intaglio printing plate for the production of halftone elementary imprints (3) having at least one engraved area on the plate surface, characterized in that the engraved area has a three-dimensional engraved relief with a continuous pattern of engraved depths.

38. Intaglio printing plate according to claim 37, wherein the engraved partial areas have different roughness.

39. Intaglio printing plate according to claim 37 or 38, wherein the three-dimensional depth profile has superimposed thereon, at least in partial areas, substructures having different orientations in the individual partial areas.