CA2699234C - Data carrier having an intaglio motif - Google Patents

Abstract

The invention relates to a data carrier (10) having a recess printing motif (12) that, when viewed with the naked eye, appears as a halftone image having a continuous tonal value progression, wherein the recess printing motif (12) comprises a plurality of fine, projecting printed lines (20) not resolvable by the naked eye that are modulated in the width and/or height thereof in order to produce the different tonal values of the halftone image.

Description

Data Carrier Having an Intaglio Motif The present invention relates to a data carrier having an intaglio motif and an intaglio plate, and an intaglio printing method for printing a motif, and a method for manufacturing such an intaglio plate.

Data carriers within the meaning of the present invention especially include security or value documents, such as banknotes, passports, identification documents, check forms, stocks, certificates, stamps, vouchers, plane tickets and the like, as well as labels, seals, packaging and other elements for product protection. In the following, the term "data carrier" encompasses all such documents and product protection means.

Normally, through suitable measures, security and value documents whose commercial or utility value far exceeds their material value are made distinguishable as authentic and discriminable from imitations and counterfeits. For this, they are most often provided with special security elements that ideally can be imitated only with great effort or not at all, and are not counterfeitable.

In the past, particularly such security elements have proven successful that can be identified by the viewer and recognized as authentic without auxiliary means, but at the same time can be manufactured only with extensive technical or financial outlay. This includes, for example, watermarks that can be introduced into the data carrier only during paper manufacture, or images produced in an intaglio printing process that feature a characteristic tactility that is easily distinguishable, also for the layperson,

-2-and that cannot be reproduced by other printing processes and especially by copiers or scanners.

Line or intaglio printing technology, especially steel intaglio printing technology, is of great importance especially for printing on security papers, such as banknotes and the like. What distinguishes intaglio printing is that linear depressions are introduced into the printing plates to produce a print image. The ink-transferring regions of the printing plate are thus present as depressions in the printing plate surface. These depressions are produced by means of a suitable engraving tool, by laser ablation or by means of etching.
In mechanically produced printing plates for intaglio printing, a wider line is produced with increasing engraving depth as a result of the usually conically tapered engraving tools. Furthermore, the ink absorption capacity of the engraved line, and thus the opacity of the printed line, increases with increasing engraving depth.

Compared with other common printing technologies, such as offset printing, line intaglio printing technology permits relatively thick inking on a data carrier. The comparatively thick ink layer produced in the line intaglio printing process, together with the partial deformation of the paper surface resulting from the paper being pressed into the engraving of the printing plate, is, with an appropriate depth of the engraving, easily tangible manually, also for the layperson, and thus easily perceptible as an authenticating feature based on its tactility. The tactility cannot be imitated with a copier, such that line intaglio printing technology offers valuable protection against counterfeits.

To be able to combine contiguous printing with tactile elements in one printing operation, it was suggested in publication WO 03/052702 A2 to

-3-provide a data carrier with a halftone image produced in intaglio printing and including directly adjacent printed sub-areas in at least one sub-region of the image, the sub-areas exhibiting certain tonal values, and at least one sub-region of the image being tactilely perceptible. Here, the term "halftone image" refers to an image that exhibits intermediate tones between the lightest and darkest place of the image.

To manufacture such a print image, in WO 03/052702 A2, an original is subdivided into sub-areas based on halftone values, and the individual tonal values or groups of tonal values are assigned, in line with the printing ink used, different engraving depths for the printing plate to be produced. Here, the tonal values of the original are translated into corresponding engraving depths on the printing plate, the engraving depth required to produce special tonal values being able to vary from printing ink to printing ink. In practical application, particularly technical depictions can be rendered well with such methods, while other halftone depictions, especially portraits, often seem unnatural.

Based on that, it is the object of the present invention to create a data carrier having high counterfeit security that exhibits a motif produced in intaglio printing and appearing as a halftone image when viewed. In particular, the intaglio motif is intended to be able to be advantageously combined with tactile elements.

The term "halftone image" is not used consistently in the literature on printing technology and especially also in patent literature. In some cases, it refers to only "true" halftone images, in other words images whose tonal values display true gradations between black and white, as can be produced for example, with photographic methods. In the field of printing technology,

-4-however, the term is also often used for line images that actually consist of only discrete, printing (e.g. black) and non-printing (e.g. white) image elements in which, however, the printing and non-printing image elements are developed to be so fine that, due to the integrative effect of the eye, an image is created that appears for the viewer to exhibit true halftone gradations. The printing or non-printing image elements are typically halftone dots that are arranged in a regular grid having a small screen ruling.
For example, at normal reading distance, the human eye can no longer distinguish the individual dots above a 60 screen, that is, a grid having a line screen frequency of 60 lines/cm, the image appears for the viewer visually smoothed and seems like a true halftone image (see, for example, H.
Kipphan, Ed., Handbuch der Printmedien (Handbook of Print Media), Springer, 2000, pages 92-93).

That said, in the context of this description, the term "halftone image" is used in the sense of a true halftone image. The fact that also a line image, in other words an image having discrete, printing and non-printing image elements, can, in an appropriately fine execution of the image elements, have the visual effect of a true halftone image for a human viewer, is expressed in the context of this description by the formulation that such an image appears as a halftone image when viewed with the naked eye.

According to the present invention, the above-mentioned object is solved by the data carrier having the features of the main claim. An intaglio printing process and an intaglio printing plate for manufacturing a data carrier according to the present invention and a method for manufacturing such an intaglio printing plate are specified in the coordinated claims. Developments of the present invention are the subject of the dependent claims.

-5-According to the present invention, a data carrier of the kind cited above includes an intaglio motif that appears as a halftone image having a continuous tonal gradation when viewed with the naked eye. Here, the intaglio motif comprises a plurality of fine, raised print lines that are not resolvable with the naked eye and that are continuously modulated in their width and/or height to produce the different tonal values of the halftone image.

Also the phrase "continuous tonal gradation" is based on the perception of the motif with a human eye. A continuous tonal gradation thus need not exhibit infinitely many different tonal values, but rather merely such a large number that the impression of a continuous gradation is created for a human viewer.

In an advantageous embodiment, the intaglio motif of the data carrier comprises a family of parallel print lines. According to current knowledge, particularly good results can be achieved if the intaglio motif comprises a regular cross-line screen that is preferably formed by two families of parallel print lines that intersect at an angle a. For the angle a, values between 40 and 80 , especially between 50 and 70 , have proven to be particularly favorable.

The parallel print lines of the intaglio motif advantageously exhibit a center-to-center distance of 400 m or less, preferably of 50 m to 200 gm, particularly preferably of 60 ~tm to 150 m and very particularly preferably of 70 gm to 120 um.

The spacing of the print lines can be constant across the entire intaglio motif, or it can also vary. For example, the intaglio motif can be subdivided into

-6-sub-regions and each sub-region exhibits a certain spacing of the lines that differs from the other sub-regions. But the spacing of the lines can also vary across the entire motif.

Furthermore, it is alternatively possible that the line spacing of two adjacent lines is continuously modulated, in other words no parallel lines are present.
With a larger spacing, lighter tones are obtained, and with smaller spacing, darker tones. In this way, the tonal gradation can be increased even further.

In an advantageous embodiment of the data carrier according to the present invention, the print lines are arranged with a precision of +/- 5gm or less, preferably of +/- 2.5 gm or less, particularly preferably of about +/- 1 m or less, especially are arranged in one or more parallel families.

The width of the print lines is preferably below 250 m and, in non-tactile regions, advantageously between 3gm and 150 m. In tactile regions, the width of the print lines can also be larger. In dark motif regions and especially in tactile print regions, the print lines can also partially overlap.

In a further advantageous embodiment, the motif is surrounded, as an outer contour, with a print line that is modulated in its width and/or height. Here, the line ends of the motif are covered by the print tine that serves as the outer contour. In particular, the print line that serves as the outer contour is modulated such that lines that taper off widely, corresponding to dark motif regions, are superimposed with a wider outer contour, and line ends that taper off narrowly, corresponding to light motif regions, with aiiarrow outer contour. The line width of the print line that serves as the outer contour is preferably in the range of 5 m to 250 m, preferably in the range of 10 m to 120 m. Coordinated with the brightness levels in the motif, for light motif

-7-regions, the width of the outer contour line is preferably in the range of 5 m to 30 m, for dark motif regions, preferably in the range of 60 m to 150 m.
According to an advantageous embodiment of the present invention, the intaglio motif includes print lines having a width of 15 m or less, especially even having a width of 10 m or less. On the one hand, a particularly large width range with a correspondingly large dynamic range can be made usable through the use of also such narrow print lines, and on the other hand, very high resolutions and very fine tonal gradations can be realized through the use of very narrow print lines.

The width and height of the print lines are preferably modulated together such that wider print lines exhibit a greater height and narrower print lines a smaller height.

The intaglio motif exhibits especially a non-tactile print region in which the print lines are not tactilely discernible. Further, the intaglio motif advantageously exhibits a tactile print region in which the print lines are tactilely discernible. Here, the tactile print region is expediently arranged in particularly dark image portions of the halftone image.

Compared with conventional methods, the present invention shows particularly great advantages in intaglio motifs that depict a representation of a person, or a portrait.

In contrast to conventional intaglio depictions in hand engraving style, in which the individual lines and dots are clearly distinguishable with the naked eye and in which the engraving inks often appear having a gray cast, the individual print lines of a print depiction produced according to the

-8-present invention are not distinguishable with the naked eye, and the engraving inks of the halftone images appear vibrant, crisp and luminous due to the high resolution.

The present invention further includes an intaglio plate for printing a motif that appears as a halftone image having a continuous tonal gradation when viewed with the naked eye. The intaglio plate includes an engraving motif that comprises a plurality of fine engraving lines that are not resolvable with the naked eye and that are continuously modulated in their width and/or depth to produce the different tonal values of the halftone image.
The engraving motif advantageously comprises a family of parallel engraving lines. Particularly good results are achieved when the engraving motif comprises a regular cross-line screen, composed of engraving lines, that is preferably formed by two families of parallel engraving lines that intersect at an angle a. For the angle a, values between 40 and 80 , especially between 50 and 70 , have proven to be particularly favorable.
The parallel engraving lines preferably exhibit a center-to-center distance of 400 gm or less, preferably of 50 gm to 200 m, particularly preferably of 60 m to 150 m and very particularly preferably of 70 m to 120 m. In particularly advantageous embodiments, the engraving lines are arranged with a high precision of +/- 5 m or less, preferably of +/- 2.5 m or less, particularly preferably of about +/-1 gm or less, especially are arranged in one or more parallel families.

In dark motif regions, the engraving lines can also partially overlap one another. To produce correspondingly narrow print lines, the engraving motif

-9-advantageously includes engraving lines having a width of 15 m or less, especially even having a width of 10 m or less.

The spacing of the engraving lines can be constant across the entire intaglio motif, or it can also vary. For example, the intaglio motif can be subdivided into sub-regions and each sub-region exhibits a certain spacing of the lines that differs from the other sub-regions. But the spacing of the lines can also vary across the entire motif.

Furthermore, it is alternatively possible that the line spacing of two adjacent lines is continuously modulated, in other words no parallel lines are present.
With a larger spacing, lighter tones are obtained, and with smaller spacing, darker tones. In this way, the tonal gradation can be increased even further.
The width and height of the engraving lines are preferably modulated together such that wider engraving lines exhibit a greater depth and narrower engraving lines a smaller depth. Such a joint modulation can be achieved, for example, using a conically tapering engraving stylus.

The engraving motif advantageously exhibits a shallow engraving region for printing a non-tactile print region in which the engraving lines exhibit a depth of up to 80 m, preferably of 2gm to 70 m. The width of the engraving lines in the shallow engraving region is preferably below 250 gm, especially between 3 m and 150 m.

Further, the engraving motif advantageously exhibits a deep engraving region for printing a tactile print region in which the engraving lines exhibit a depth of 70 gm to 300 m, preferably of 70 m to 200 m, particularly preferably of 80 m to 120 m. The width of the engraving lines in the deep

-10-engraving region is preferably below 400 m, especially between 120 gm and 250 m.

The present invention also includes a method for manufacturing an intaglio plate for printing a motif that appears as a halftone image having a continuous tonal gradation when viewed with the naked eye, having the method steps:

- providing a printing plate having a printing plate surface, - engraving in the printing plate surface a plurality of fine engraving lines, not resolvable with the naked eye, with a continuous modulation in their width and/or depth such that an engraving motif is created for producing the different tonal values of the halftone image.

Here, the local engraving line width and/or depth to be engraved is advantageously determined at this local position from the tonal value of the halftone image to be depicted. Here, lighter tonal values correspond to narrower and/or less deep engraving lines, darker tonal values to wider and/or deeper engraving lines. The engraving lines determined in this way can then be produced with an electronically controlled stylus or another method in the respective locally required width and depth.

In the method according to the present invention, preferably, a) in the motif, a tactile and a non-tactile print region are established, and associated deep and shallow engraving regions are established for printing the tactile and the non-tactile print region, and

- 11 -b) for both print regions, the local engraving line width and/or depth to be engraved are determined at this position from the tonal value of the halftone image to be depicted.

Further, in an advantageous method variant, cl) the engraving lines in both engraving regions are produced in the printing plate in accordance with the determined local width and/or depth, and di) in the deep engraving region, further engraving lines having a depth of 70 m to 300 m, preferably of 70 m to 200 m, particularly preferably of 80 m to 120 gm are produced.

According to another likewise advantageous method variant, cz) the engraving lines in the shallow engraving region are produced in the printing plate in accordance with the determined local width and/or depth, and d2) the engraving lines in the deep engraving region are produced having a depth of 70 m to 300 m, preferably of 70 gm to 200 m, particularly preferably of 80 pim to 120 m.

According to a further, likewise advantageous method variant,

-12-c3) the engraving lines in the shallow engraving region can also be produced in the printing plate in accordance with the determined local width and/or depth, and d3) the engraving lines in the deep engraving region can also be produced having an excessive width and/or depth compared with the determined local width and/or depth such that, at least in part, engraving lines are produced having a depth of 70 m to 300 ttm, preferably of 70 gm to 200 m, particularly preferably of 80 m to 120 m.

The engraving of the printing plate can, in principle, be carried out by means of laser beam or through etching, but engraving by means of an electronically controlled, rotating stylus is currently preferred.

Further exemplary embodiments and advantages of the present invention are explained below by reference to the drawings, in which a depiction to scale and proportion was omitted in order to improve their clarity.
Shown are:

Fig. 1 a schematic diagram of a banknote having an intaglio motif according to the present invention, Fig. 2 a detailed section of the banknote in fig. 1 in the region of the intaglio motif, in top view, Fig. 3 schematically, in cross section, an intaglio plate according to the present invention for printing a motif appearing as a halftone image, and

-13-Fig. 4 in (a) and (b), two simplified representations of detailed top views of printing plates according to the present invention, having engraving lines in the form of cross-line gratings.

The invention will now be explained using a banknote as an example. Fig. 1 shows a banknote 10 that is provided with an intaglio motif 12 that appears as a halftone image having a continuous tonal gradation when viewed with the naked eye. In dark image regions, the intaglio motif 12 optionally additionally includes tactile sub-regions 18 in which the relief pattern of the intaglio printing is tactilely discernible for the user and thus forms a tangible marking.

In addition to the intaglio motif 12, the banknote 10 typically exhibits further print images that are produced with different printing processes. For example, the banknote 10 can include a pattern 14 produced in offset printing, such as a guilloche pattern composed of regularly interlaced lines, as well as a serial number 16 imprinted in letterpress printing. Regions produced by screen printing or other printing methods can also be provided.
To allow the impression of a continuous tonal gradation to be created in the intaglio motif 12, this motif comprises a plurality of fine, raised print lines 20 that are not resolvable with the naked eye, as shown in top view in the detailed section in fig. 2. In the exemplary embodiment, the print lines 20 form a family of parallel print lines having a spacing d measured from center to center.

To produce the different tonal values of the halftone image, the print lines are continuously modulated in their width and height, as can be seen in fig. 2

-14-for the print line width. Here, in lighter image regions (such as at the right and left edge of the section in fig. 2), the print lines 20 exhibit a small width and height, in darker image regions (such as in the center of the section in fig. 2) a greater width and height. In the non-tactilely-discernible regions, the width b of the print Iines 20 varies between a minimum width bm;I, and a maximum width bna, The maximum width can also be larger in some regions than the spacing d of the lines such that the print lines 20 overlap and form particularly dark motif regions.

In the exemplary embodiment, due to the production of the engraving lines in the intaglio plate with a conical stylus, the width and height of the print lines are positively correlated, in other words, wide print lines exhibit a greater height, narrower print lines a smaller height. Thus, in accordance with the width varying between b,,,iõ and bn,z,,,, also the height of the print lines 20 in the non-tactilely-discernible regions varies between a minimum height hn,lõ and a maximum height hn,,,. Here, the maximum height hn,a, is chosen taking into account the composition of the printing ink used and of the banknote paper such that the print lines 20 are not tangible for the user in the non-tactile region.

In contrast, the width bt and the height ht of the print lines 20 in the tactilely discernible regions 18 are above the maximum values of the non-tactilely-discernible regions, thus, they constitute very dark image regions. In particular, taking into account the composition of the printing ink and banknote paper, the height ht is chosen to be so large that a tangible marking 18 in the intaglio motif 12 is created for the user. Within a tactilely discernible region 18, the width and height of the print lines 20 can be constant or exhibit a modulation to still render drawing portions within the dark image regions 18.

-15-The spacing d of the print lines is below 400 m, preferably in the range of 70 gm to 120 m, and is 100 m in the exemplary embodiment in fig. 2. The width b of the print lines 20 in the exemplary embodiment varies between bmiõ = 4 m and bmaX = 140 gm in the non-tactilely-discernible regions. The height h of the print lines 20 is always below 70 gm such that they are not tactilely discernible.

In the tactilely discernible regions 18, in contrast, the height of the print lines is preferably between 80 m and 120 m, for example 100 m, such that a tactilely well discernible marking is created there. In this region, the center-to-center spacing d of the print lines is, for example, only 80 m.

With these parameters, the print lines 20 are not resolvable even for the naked eye, the intaglio motif 12 thus appears for a viewer as a halftone image having a continuous tonal gradation that is determined by the local width and height of the print lines 20. The tactilely discernible regions 18 lend the intaglio motif an additional authenticating mark that can be easily distinguished and checked upon rubbing the banknote 10 between the fingers. Since the tactile regions 18 are arranged in particularly dark image portions of the depicted halftone image, they merge visually inconspicuously with the remaining regions of the halftone image.

Fig. 3 shows schematically, in cross section, an intaglio plate 30 for printing a motif appearing as a halftone image, such as the above-described intaglio motif 12. In the intaglio plate 30, an engraving motif that comprises a plurality of fine engraving lines that are not resolvable with the naked eye and that are continuously modulated in their width and/or depth to

-16-produce the different tonal values of the halftone image corresponds to the printed motif 12.

In the illustration in fig. 3 are shown, for example, three sections of the engraving lines 32, 34, 36 that serve to produce a light tonal value in the motif (engraving line 32), a dark tonal value in the motif (engraving line 34) and to produce the tactilely discernible region 18 (engraving line 36).

All engraving lines are produced with an electronically controlled, conically tapering engraving stylus, through which an increasing width of the engraving lines results with increasing engraving depth. For example, in the exemplary embodiment, when an engraving stylus having a conical opening angle of about 80 is used, an engraving depth t- b/(2*tan(80 /2)) results, in other words, the engraving depth is nearly 60% of the engraving width.

According to the present invention, for the engraving of the intaglio print motif, it is also possible to use different engraving styli having different conical opening angles. The conical opening angle preferably ranges from 60 to 100 . For example, the intaglio motif can be subdivided into sub-regions that are worked with engraving styli having different conical opening angles. Preferably, sub-regions having a lighter tone are engraved with an engraving stylus that exhibits a conical opening angle of 40 , while sub-regions having a darker tone are engraved with an engraving stylus that exhibits a conical opening angle of 100 . Instead of subdividing the motif into sub-regions, also individual lines can be engraved with different engraving styli.

Of the engraving lines shown for illustration in fig. 3, the section of the engraving line 32 exhibits an engraving depth of ti = 25 m and,

-17-accordingly, a width b1 of around 40 m, the section of the engraving line 34 an engraving depth of t2 = 50 m and, accordingly, a width b2 of around 80 m, and the section of the engraving line 36 an engraving depth of t3 = 100 m and, accordingly, a width b3 of around 165 m.

Even if, in fig. 3, only one engraving line 32, 34, 36 is depicted in each case, the intaglio plate 30 includes, of course, a plurality of such engraving lines, which can be arranged in parallel or especially in the form of a cross-line grating composed of parallel engraving lines. Here, the spacing of the parallel engraving lines 32, 34 in the non-tactile print region is 100 m in the exemplary embodiment, the spacing of the parallel engraving lines 36 in the tactile print region 80 m.

With a width of 40 ttm and a distance of 100 m, the engraving lines 32 produce a light tonal value within the motif 12 upon printing. The engraving lines 34 having a width of 80 gm and a spacing of 100 m already produce a very dark tonal value upon printing. The engraving Iines 36 that, at a spacing of 80 m, exhibit a width of 165 ttm, additionally produce upon printing, besides a very dark tonal value, a tangible marking 18 due to the thick inking and the deformation of the banknote paper.

Following the above, it is understood that the width and depth of the engraving lines are modulated along their dimension in accordance with the tonal value to be depicted locally, such that the cross section in fig. 3 shows, in each case, only a local width and depth of a section of the engraving lines 32, 34, 36. The sections 32, 34, 36 can even represent sections of the same engraving line at different spots along its dimension. It is further understood that the width and depth of the engraving lines are varied continuously in a

-18-specified width and depth range, and do not exhibit only the discrete values shown for illustration in fig. 3.

The parallel engraving lines are produced in the intaglio plate 30 with a high precision of +/- 5 m, preferably even with the extraordinarily high precision of +/-1 gm. Due to this high precision, extraordinarily fine tonal value differences can be achieved.

Furthermore, through series of tests, the inventors found that, with an arrangement of the engraving lines in a suitable cross-line screen, particularly stable printing is possible at different engraving depths. With reference to fig. 4(a), which shows a section 40 of a top view of a printing plate according to the present invention, such a cross-line screen consists of two families 42, 44 of parallel engraving lines that intersect at an angle a.
To improve diagram clarity, the width/depth modulation of the engraving lines that is, of course, present in practice, is not depicted in fig. 4(a).
Particularly good results are obtained with cross-line screens in which the angle a is between 40 and 80 , especially about 60 . For the spacing, widths and depths of the engraving lines 42, 44, each of which are parallel, the above explanations given for parallel engraving lines in general apply.

The engraving lines of the printing plate 30 need not necessarily run straight, as illustrated in the section 50 depicted in fig. 4(b), which shows two intersecting, curving line families 52, 54. Here, too, to improve diagram clarity, the existing width/ depth modulation of the engraving lines is not depicted.

-19-To obtain from a specified halftone original an intaglio plate 30 having an appropriate engraving motif, according to the present invention, the following approach, for example, can be used:

As the base modulation for the halftone image, a cross-line screen having engraving lines of an orientation of +/- 40 (in other words an intermediate angle a = 80 ) is used, as depicted schematically in fig. 4(a). Such a cross-line screen can be printed particularly stably with the values for width, depth and spacing of the engraving lines considered here.

The calculation of the form and position of the engraving lines is preferably done with the aid of a computer, it being possible to use commercially available programs that permit the calculation of the engraving depth based on the tonal values to be depicted in the halftone image.

In a next step, a press proof is effected of a grayscale ramp with the desired steel printing ink with a continuous range of 0 - 100% area coverage and the chosen engraving rendition, for example in the form of the chosen cross-line screen.

The ha]ftone region to be used, called impact region in the following, is established based on the press proof. The established scope can comprise, for example, a region of 3% - 40% area coverage.

Then the halftone original is rendered within the impact region, with lighter tonal values corresponding to a shallower engraving, darker tonal values to a deeper engraving. Here, the halftone image must generally be adapted to the desired specific printing conditions through image retouching. The particular print characteristics of the steel printing ink are also taken into

-20-account here, especially the very high pigment content, which leads to a very large spread from light to dark, as well as different additives, such as absorbers, lithopone, transparent white, maschine readable features and the like, which in some cases change the scumble behavior of the chromatic ink considerably.

In a further method step, the desired tactile regions of the motif are established. For this, particularly dark regions of the halftone original are detected and supplemented with the desired extra sections. To achieve the tactile properties, the patterns created in this way are overdrawn (superelevated), possibly likewise subjected to retouching, and first saved separately.

Then, with the aid of a computer and a suitable program, the halftone original (projection), with the engraving definition and the desired tactile region, is calculated and, based on the calculated engraving lines, a printing plate produced with an electronically controlled stylus.

Here, the base modulation can be combined with the tactile portion in different ways. In the simplest rendition, the tactile portion is simply transferred to the existing basic cut model. Alternatively, the tactile portion can be omitted from the basic model and then be newly applied to the uncut area. In a further variant of the present invention, the tactile portion is omitted from the basic model and, thereafter, the tactile region again calculated anew from the halftone image such that a depth modulation can be created here that renders individual drawing portions.

As a result, a cut printing plate is present that, through the different depths and widths of the engraving lines, renders the desired tonal gradation of the

-21-halftone image and exhibits the tactile elements integrated in the halftone rendition. After press proof, review and, if applicable, correction, the design for the motif 12 can be incorporated into the cut file of the banknote or another desired value document.

The approach according to the present invention offers especially the following advantages:

- The steel printing ink facilitates a broad spectrum of light to dark that can be taken advantage of with the method according to the present invention.

- Desired tactile elements can be integrated in the motif design.

- The method permits an attractive rendering of halftone originals, especially also for the banknote reverse.

- Line printing is an attractive alternative to stochastic screening.
- When manufacturing the printing plate, the cutter can stay in the material continuously without permanent striking and, in this way, facilitate an execution favored by the method.

Claims (44)

Claims

1. A data carrier having an intaglio motif that appears as a halftone image having a continuous tonal gradation when viewed with the naked eye, the intaglio motif comprising a plurality of fine, raised print lines that are not resolvable with the naked eye and that are continuously modulated in their wid:th and/or height to produce the different tonal values of the halftone image.

2. The data carrier according to claim 1, characterized in that the intaglio motif comprises a family of parallel print lines.

3. The data carrier according to claim 1 or 2, characterized in that the intaglio motif comprises a regular cross-line screen.

4. The data carrier according to claim 3, characterized in that the cross-line screen is formed by two families of parallel print lines that intersect at an angle .alpha..

5. The data carrier according to claim 4, characterized in that the angle a is between 40° and 80°, preferably between 50° and 70°.

6. The data carrier according to any one of claims 2 to 5, characterized in that the parallel print lines exhibit a center-to-center distance of 400 µm or less, preferably of 50 µm to 200 µm , particularly preferably of 60 µm to 150 µm and very particularly preferably of 70 µm to 120 µm .

7. The data carrier according to any one of claims 1 to 6, characterized in that the print lines are arranged with a precision of +/- 51 µm or less, preferably of +/- 2.5 µm or less, particularly preferably of about +/- 1 µm or less, especially are arranged in one or more parallel families.

8. The data carrier according to any one of claims 1 to 7, characterized in that the print lines partially overlap in dark motif regions.

9. The data carrier according to any one of claims 1 to 8, characterized in that the intaglio motif includes print lines having a width of 15 µm or less, especially in that the intaglio motif includes print lines having a width of µm or less.

10. The data carrier according to any one of claims 1 to 9, characterized in that the width and height of the print lines are modulated together such that wider print lines exhibit a greater height and narrower print lines a smaller height.

11. The data carrier according to any one of claims 1 to 10, characterized in that the intaglio motif exhibits a non-tactile print region in which the print lines are not tactilely discernible.

12. The data carrier according to claim 11, characterized in that the width of the print lines in the non-tactile print region is below 250 µm, preferably between 3 µm and 150 µm.

13. The data carrier according to any one of claims 1 to 12, characterized in that the intaglio motif exhibits a tactile print region in which the print lines are tactilely discernible.

14. The data carrier according to claim 13, characterized in that the width of the print lines in the tactile print region is below 400 µm , preferably between 120 µm and 250 µm .

15. The data carrier according to claim 13 or 14, characterized in that the tactile print region is arranged in particularly dark image portions of the halftone image.

16. The data carrier according to any one of claims 1 to 15, characterized in that the intaglio motif constitutes a representation of a person, or a portrait.

17. An intaglio plate for printing a motif that appears as a halftone image having a continuous tonal gradation when viewed with the naked eye, having an engraving motif that comprises a plurality of fine engraving lines that are not resolvable with the naked eye and that are continuously modulated in their width and/ or depth to produce the different tonal values of the halftone image.

18. The intaglio plate according to claim 17, characterized in that the engraving motif comprises a family of parallel engraving lines.

19. The intaglio plate according to claim 17 or 18, characterized in that the engraving motif comprises a regular cross-line screen composed of engraving lines.

20. The intaglio plate according to claim 19, characterized in that the cross-line screen is formed by two families of parallel engraving lines intersecting at an angle .alpha..

21. The intaglio plate according to claim 20, characterized in that the angle .alpha. is between 40° and 80°, preferably between 50° and 70°.

22. The intaglio plate according to any one of claims 18 to 20, characterized in that the parallel engraving lines exhibit a center-to-center distance of 400 µm or less, preferably of 50 µm to 200 µm , particularly preferably of 60 µm to 150 µm and very particularly preferably of 70 µm to 120 µm .

23. The intaglio plate according to any one of claims 17 to 22, characterized in that the engraving lines are arranged with a precision of +/-µm or less, preferably of +/- 2.5 µm or less, particularly preferably of about +/- 1 µm or less, especially are arranged in one or more parallel families.

24. The intaglio plate according to any one of claims 17 to 23, characterized in that the engraving lines in dark motif regions partially overlap.

25. The intaglio plate according to any one of claims 17 to 24, characterized in that the engraving motif includes engraving lines having a width of 15 µm or less, especially in that the engraving motif includes engraving lines having a t gift of 10 µm or less.

26. The intaglio plate according to any one of claims 17 to 25, characterized in that the width and height of the engraving lines are modulated together such that wider engraving lines exhibit a greater depth and narrower engraving lines a smaller depth.

27. The intaglio plate according to any one of claims 17 to 26, characterized in that the engraving motif exhibits a shallow engraving region for printing a non-tactile print region in which the engraving lines exhibit a depth of up to 80 µm, preferably of 2 µm to 70 µm.

28. The intaglio plate according to claim 27, characterized in that the width of the engraving lines in the shallow engraving region is below 250 µm, especially between 3 µm and 150 µm.

29. The intaglio plate according to any one of claims 17 to 28, characterized in that the engraving motif exhibits a deep engraving region for printing a tactile print region in which the engraving lines exhibit a depth of 70 µm to 300 µm, preferably of 70 µm to 200 µm, particularly preferably of 80 µm to 120 µm.

30. The intaglio plate according to claim 29, characterized in that the width of the engraving lines in the deep engraving region is below 400 µm, especially between 120 µm and 250 µm.

31. The intaglio plate according to any of claims 17 to 30, characterized in that the engraving motif is produced with a stylus.

32. An intaglio printing method for printing a motif that appears as a halftone image having a continuous tonal gradation when viewed with the naked eye, in which an intaglio plate according to any one of claims 17 to 31 is used.

33. A method for manufacturing an intaglio plate for printing a motif that appears as a halftone image having a continuous tonal gradation when viewed with the naked eye, having the method steps:
providing a printing plate having a printing plate surface, engraving in the printing plate surface a plurality of fine engraving lines, not resolvable with the naked eye, with a continuous modulation in their width and/or depth such that an engraving motif is created for producing the different tonal values of the halftone image.

34. The method according to claim 33, characterized in that the local engraving line width and/or depth to be engraved is determined at this local position from the tonal value of the halftone image to be depicted.

35. The method according to claim 34, characterized in that the engraving lines are produced with an electronically controlled stylus in the respective locally required width and depth.

36. The method according to any one of claims 33 to 35, characterized in that the width and depth of the engraving lines are modulated together such that wider engraving lines exhibit a greater depth, and narrower engraving lines a smaller depth.

37. The method according to any one of claims 33 to 36, characterized in that the engraving lines are formed in the form of a family of parallel engraving lines or in the form of a cross-line screen composed of two families of parallel engraving lines that intersect at an angle .alpha..

38. The method according to any one of claims 33 to 37, characterized in that the parallel engraving lines are produced having a center-to-center distance of 400 µm or less, preferably of 50 µm to 200 µm, particularly preferably of 60 µm to 150 µm and very particularly preferably of 70 µm to 120 µm.

39. The method according to any one of claims 33 to 38, characterized in that a) in the motif, a tactile and a non-tactile print region are established, and associated deep and shallow engraving regions are established for printing the tactile and the non-tactile print region, and b) for both print regions, the local engraving line width and/or depth to be engraved are determined at this position from the tonal value of the halftone image to be depicted.

40. The method according to claim 39, characterized in that c1) the engraving lines in both engraving regions are produced in the printing plate in accordance with the determined local width and/or depth, and d1) in the deep engraving region, further engraving lines are produced having a depth of 70 µm to 300 µm, preferably of 70 µm to 200 µm, particularly preferably of 80 µm to 120 µm.

41. The method according to claim 39, characterized in that c2) the engraving lines in the shallow engraving region are produced in the printing plate in accordance with the determined local width and/or depth, and d2) the engraving lines in the deep engraving region are produced having a depth of 70 µm to 300 µm, preferably of 70 µm to 200 µm, particularly preferably of 80 µm to 120 µm.

42. The method according to claim 39, characterized in that c3) the engraving lines in the shallow engraving region are produced in the printing plate in accordance with the determined local width and/or depth, and d3) the engraving lines in the deep engraving region are produced having an excessive width and/or depth compared with the determined local width and/or depth such that, at least in part, engraving lines are produced having a depth of 70 µm to 300 µm, preferably of 70 µm to 200 µm, particularly preferably of 80 µm to 120 µm.

43. The method according to any one of claims 33 to 42, characterized in that a rotating stylus is used for engraving.

44. The method according to any one of claims 33 to 42, characterized in that the engraving is carried out by means of a laser beam or through etching.