Title of Invention	DATA CARRIER WITH AN OPTICALLY VARIABLE STRUCTURE AND METHOD FOR PRODUCING THE SAME
Abstract	The invention relates to a data carrier (1) with an optically variable structure (2) having an embossed structure with raised areas and a first coating contrasting with the surface of the data carrier. The embossed structure and the first coating are so combined that at least parts of the coating are completely visible upon perpendicular viewing but concealed upon oblique viewing so that a tilt effect arises upon alternate perpendicular and oblique viewing. The first coating is provided only in certain areas. Additionally, the optically variable structure has at least in partial areas a second coating likewise contrasts with the data carrier surface and disposed in overlap with the first coating at least in partial areas.

Title of Invention

DATA CARRIER WITH AN OPTICALLY VARIABLE STRUCTURE AND METHOD FOR PRODUCING THE SAME

Abstract

The invention relates to a data carrier (1) with an optically variable structure (2) having an embossed structure with raised areas and a first coating contrasting with the surface of the data carrier. The embossed structure and the first coating are so combined that at least parts of the coating are completely visible upon perpendicular viewing but concealed upon oblique viewing so that a tilt effect arises upon alternate perpendicular and oblique viewing. The first coating is provided only in certain areas. Additionally, the optically variable structure has at least in partial areas a second coating likewise contrasts with the data carrier surface and disposed in overlap with the first coating at least in partial areas.

Full Text	This invention relates to a data carrier with an optically variable structure having an embossed structure with raised areas and a first coating contrasting with the surface of the data carrier, the embossed structure and the coating being so combined that at least parts of the coating are completely visible upon perpendicular viewing but con- cealed upon oblique viewing so that a tilt effect arises upon alternate perpendicular and oblique viewing. The invention further relates to a method for producing such a data carrier. It has been known for some time to equip data carriers, such as bank notes, pa- pers of value, credit cards or ID cards or the like, with optically variable security ele- ments, in particular optically variable diffraction structures such as holograms. Protec- tion from forgery by holograms is based on the different optical impression of said holograms that occurs upon a change of viewing angle relative to trie hologram. Said optically variable impression cannot be rendered by copying machines since copying machines only render the appearance of the hologram from a certain viewing angle. A data carrier with such a hologram is known for example from EP 0 440 045 A2. This print proposes applying the hologram to the data carrier as a prefabricated element or as an embossing in a lacquer layer applied to the data carrier. However, there are other optically variable security elements that can be pro- vided on a data carrier. Thus, it is known for example from CA 1 019 012 to provide a bank note in a partial area of its surface with a parallel printed line pattern. To produce the optically variable effect, a line structure is additionally embossed into the data car- rier in the area of the printed line pattern so as to form flanks visible only at certain viewing angles. Selectively disposing the printed line pattern on like-oriented flanks of the embossed line structure causes the line pattern to be visible upon oblique viewing of the flanks provided with the lines. Upon oblique viewing of the rear side of the flanks the line pattern is not recognizable. The antiforgery effect of such embossed optically variable security elements can be improved further if additional visually recognizable effects are produced by selec- tively changing the line pattern or embossed structure. Examples of such additional effects are described in WO 97/17211 and WO 02/20280. The optically variable effect of the latter known security elements arises funda- mentally from the combination of a print with a blind embossing that is preferably produced by intaglio printing. Blind embossing has the disadvantage that it cannot be integrated into a colored intaglio image but can only be used as an isolated security feature. This is because a relatively great distance between the blind embossing areas and the ink-carrying areas is required to make sure that absolutely no ink gets into the blind embossing depressions when the intaglio printing plate is inked. The invention is therefore based on the problem of proposing a data carrier with an optically variable security element of the abovementioned kind that can be inte- grated into a printed image. This problem is solved by the features of the independent claims. Developments are the subject matter of the subclaims. The invention is based on the finding that the optically variable effect of the se- curity element is retained if an ink-carrying embossing is used instead of the blind em- bossing. That is, the optically variable structure has at least in partial areas a second coating likewise contrasting with the data carrier surface and disposed congruent to the raised areas of the embossed structure. The second coating offers the advantage of sta- bilizing the embossed structure without an additional printing operation. Moreover, the inventive security element has the advantage that it can be inte- grated into an intaglio motif and thus into the representational and color design of the main motif. Intaglio printing is characterized in that linear depressions are provided in the printing plates to produce a printed image. Areal representations are also produced by closely adjacent engraved lines, the individual engraved lines normally being fractions of a millimeter wide. For the printing operation the engraved lines of the plate are filled with ink. Sur- plus ink is removed from the plate with the help of a wiping cylinder or doctor blade such that the engraved lines are filled with ink up to the edge. During the printing op- eration the data carrier to be printed, normally paper, is finally pressed onto the plate with high pressure by means of a pressure cylinder having an elastic surface. The data carrier is thereby pressed into the ink-filled engraved lines of the plate, thus coming in contact with the ink. When the data carrier is detached it pulls the ink out of the de- pressions of the engraved lines. The thus produced printed image has printed lines that vary in ink layer thickness depending on the depth of engraving. The data carrier is pressed into the depressions of the plate so strongly that it not only receives ink from the depressions but is also simultaneously embossed. When translucent inks are used in intaglio printing, light color tones are obtained if a white data carrier is printed with thin ink layers, and darker color tones if printed with thick ink layers. This effect can also be utilized within the scope of the invention to produce different color effects and increase the contrast of the tilt effect. Likewise, it is possible to combine translucent and nontranslucent inks. The inventive optically variable structure can therefore be integrated into the printing plate of an intaglio motif in a very simple way by providing the embossed structure likewise in the form of depressions in the plate. During the printing operation the depressions belonging to the embossed structure are filled with an ink having for example the same color as the intaglio motif to be printed. This ink layer, which is transferred to the data carrier with the embossing operation, forms the inventive sec- ond coating disposed congruent to the raised areas of the embossed structure. It is not necessary for the total embossed structure to be inked with this color. Only partial areas of the embossed structure can also be provided with a color. Alter- natively, it is also possible to provide the embossed structure with different colors or a color flow. Such a color flow can be produced via a color split whereby the printing plate is accordingly inked by means of single color stencils. Preferably, the color of the second coating is integrated into the color design of the intaglio motif. The color split and a corresponding choice of printing inks employed are used se- lectively here to control the contrast of the optically variable structure. The color split can also be used to make parts of the optically variable structure machine-readable by adding at least one feature substance, such as a luminescent sub- stance, magnetic substance or electrically conductive substance, to at least one of the inks. Different parts of the optically variable structure can also be provided with dif- ferent feature substances. Alternatively, the total optically variable structure can also be equipped with a uniform machine-readable property. The optically variable structure can be directly adjacent to the intaglio motif or else be part of the steel intaglio motif. Since such intaglio motifs are primarily applied in security printing, the inventive data carrier is preferably a paper of value, in particular a bank note. The paper of value can be a security paper made of cotton fibers, a paper containing synthetic fibers and/or chemical pulp, or consist of pure plastic foils. Such a paper of value can also be used advantageously for protecting any products and goods. The second coating disposed in the area of the embossed structure can moreover have a color contrasting with the first coating and be disposed at least in partial over- lap with the first coating. Further, one of the coatings can have machine-readable properties at least in certain areas. These may be for example magnetic, electrically conductive or luminescent properties. Finally, the data carrier can have a metallic background layer in the area of the optically variable structure. The embossed structure is preferably executed as a screen structure. It can be tri- angular, but also trapezoidal, sinusoidal, semicircular or another shape. Preferably, the embossed structure is executed as a line screen with a constant screen ruling. In some embodiments, however, it can also be expedient to use different screen rulings. For example, the screen ruling can increase continuously in the edge area of the optically variable structure so that the embossed structure quasi tapers out. The same effect can be obtained by a continuous reduction of line width with constant or increasing screen ruling. In this edge area the first coating can be adapted in accordance with the em- bossed structure or be completely lacking. Further effects can be obtained if the flank angles vary within a line of the em- bossed structure executed as a line screen. To better bring out the optically variable effects, the embossed structure can be subdivided into partial areas where different partial embossed structures are provided, as described in WO 02/20280. The disclosure of this print is incorporated in the pres- ent invention by reference. The partial areas preferably form a two-dimensional matrix having m partial ar- eas in the horizontal direction and n partial areas in the vertical direction, where m, n = 1, preferably m,n = 2. The partial embossed structures in at least two adjoining partial areas are disposed mutually offset by a fraction, in particular one third, of the screen ruling. The first coating is preferably a print likewise formed as a screen structure, whereby the individual screen elements can be designed at will. However, a line screen, with a constant screen ruling is preferably used. According to a preferred em- bodiment, said line screen consists of printed lines of any desired color design. The print is done by any desired printing process, such as offset or screen printing. Any desired indirect printing processes, such as indirect letterpress, can also be applied. The methods moreover make it possible to provide the first coating with a color flow, a so-called "rainbow blend." Printed screen and embossed structure are adjusted to each other, preferably such that the width of the printed screen lines is somewhat smaller than the length of the flanks of the embossed structure lines and that they extend parallel or largely parallel. Printed screen and embossed structure need not necessarily extend in a straight line, they can instead also be designed in the form of wavy lines, etc. The line widths are between 25 microns and 300 microns, preferably between 55 microns and 150 mi- crons. If the line screen is composed of printed, spaced-apart lines, a ratio of about 1 :1 is preferably selected for the ratio of printed to unprinted areas. If a line width in the order of magnitude of about 100 microns is additionally selected, the lines can virtu- ally no longer be resolved by the eye and a homogeneous color effect arises. That is, the line screen is visually perceived only as a homogeneous colored surface. Addition- ally, the lines can be executed thicker in certain areas and thus represent for example a halftone image or another motif. Preferably, the lines only have thickened areas on one side. This likewise leads to stronger contrast. Alternatively, the lines can have gaps.to produce an additional visually recognizable pattern. The first coating and/or the em- bossed structure can also be executed so as to repeat the content of other information present on the document of value to make comparison possible. Quite generally it is to be underlined that the color design of the security element can be adjusted at will by a corresponding color choice of first and second coatings, since the mixture of the two colors is always perceived at least in a top view. Likewise, the information perceptible from different viewing angles can be adjusted by a corre- sponding choice of parameters, such as color, line thickness and line modulation of the first coating and flank angle, flank height and flank modulation of the embossed struc- ture. Rasterization of the print can be dispensed with if optically variable inks are used, i.e. inks having different optical effects dependent on the angle of vision. These may be high-gloss, e.g. metallic, layers or else inks that change their color effect them- selves in angle-dependent fashion, as is the case for example with liquid crystal pig- ment inks. However, an inventive optically variable structure with a rasterized first coating can also be additionally underlaid or covered with an optically variable printed image. This is preferably done with printing inks having interference layer and/or liquid crys- tal pigments. An additional metallic background is also conceivable. The printed im- age can be executed to be positive or negative. The use of liquid crystals additionally provides elevated protection from forgery since the printed image in this case has light-polarizing properties that can be read by machine. This holds in particular when the printed image is composed of partial printed images, with liquid crystals having different polarization properties being used for the partial printed images. The inventive optically variable structure can be underlaid or covered, not with an additional printed image, but with a foil element, such as a diffraction structure em- bossed into a lacquer layer. Here, any desired layer structures and types of foil ele- ments can be used, such as real holograms, lattice structures, volume holograms that are executed to be transparent, semitransparent or opaque. According to a preferred embodiment, the inventive optically variable structure consists of a print in the form of a printed line screen, a first color and an embossed structure superimposed on said line screen and likewise executed in linear fashion whose raised areas are provided with a further color contrasting with said first color. Said second color is preferably produced by means of translucent printing inks that have a certain transparency so that the color of the first coating shines through said color and the viewer thus perceives a mixed color in the superimposed areas. Espe- cially good effects are achieved if there is a complementary contrast between the first and second colors. When viewing said optically variable structure perpendicular to the data carrier surface, the viewer ideally recognizes only a uniform color effect. When the data car- rier is tilted or the viewing angle changed, parts of the first and/or second coating are concealed by the embossed structure, so that in certain areas the color effect of the first or second coating or of the mixed color of the two coatings predominates and thus variable color effects arise. This interplay of colors appears all the more clearly the better-contrasting the colors of the two coatings are. For example, a dark, e.g. black, line screen can be com- bined with a well-contrasting colored intaglio print with translucent inks, such as yel- low or other light color tones. The first coating in the form of a black line screen is preferably printed on here by the offset process. Alternatively, a further preferably all-over ink layer can be disposed under the first preferably screenlike coating. Said layer serves to stabilize the paper in the area of the security element and permits sharper edges in the area of the embossed structure. Said layer can be executed as a primer or colored lacquer layer or else contribute addi- tionally to the color design of the security element if said layer has a color contrasting with the first coating. One can use conventional printing inks or else special-effect inks, such as luminescent inks or printing inks containing interference or liquid crystal pigments. Finally, additional information can also be incorporated by designing the em- bossed structure and/or first coating accordingly. For example, the raised areas of the embossed structure can have different heights. If the embossed structure is produced by intaglio printing, this means that the engraving depths for the embossed structure are selected differently. The areas of lower engraving depth are filled with less ink in the printing or embossing operation and produce areas with a lighter color tone if translucent inks are used. In this way the inventive second coating can be used to pro- duce additional information visually recognizable at all viewing angles. Due to the different embossing heights, however, a change of viewing angle yields additional op- tically variable effects that are caused by the relative position of the first and second coatings as well as the embossed structure and the interplay thereof. The additional information can also be emphasized by an unembossed edge con- tour, as already described in WO 02/20280. Alternatively, the edge contour can also be provided with the second coating and the embossed structure according to the inven- tion. As mentioned above several times, the inventive optically variable security ele- ment is preferably produced in two printing operations. In a first printing operation, preferably by the offset process or an indirect printing process, the first coating is printed on the data carrier. In the second printing operation, which is preferably done by intaglio according to the invention, the embossed structure and the second coating are finally transferred to the data carrier simultaneously. Similar optical effects can be achieved if the two coatings are printed on in regis- ter to each other by offset and/or screen printing and this printed area is then provided with a blind embossing likewise in register. All embodiments described within the scope of the invention can be produced in this way. According to a special embodi- ment, for example, a line screen in a first color can be applied and at least partly in overlap therewith a second coating of translucent inks all over. In a last step, the total printed area is provided with a blind embossing in the form of a line screen in register. However, it is also possible to use the reverse order, providing first the embossed structure and second coating on the data carrier and then the first coating. Further embodiments and advantages of the invention will be explained with ref- erence to the figures, in which: Fig. 1 shows an inventive data carrier, Fig. 2 shows a section along A - A in Fig. 1, Fig. 3 shows a schematic representation of the relative position between the first and second coatings of the inventive security element in a first embodiment, Fig. 4 shows a schematic representation of the relative position between the first and second coatings of the inventive security element according to a second embodi- ment, Fig. 5 shows a schematic representation of the relative position of the first and second coatings of the inventive security element according to a third embodiment, the embossed structure having raised areas of different heights, Fig. 6 shows an inventive embossing mold in cross section for producing the em- bossed structure with additional information, Fig. 7. shows a further embodiment of the inventive embossing mold, Fig. 8 shows a further variant of the inventive security element, Fig. 9 shows a further variant of the inventive security element, Fig. 10 shows a special embodiment of the inventive security element wherein the embossed structure is present in the form of a matrix, Fig. 11 shows a special embodiment of the embossed structure of the inventive security element. Fig. 1 shows inventive data carrier 1 with optically variable structure 2. Optically variable structure 2 is a security feature that can be checked without aids and is used optionally alongside further security features for checking the authenticity of the data carrier. The further security features may be for example a security thread, watermark or the like. As preferred within the scope of the invention, optically variable structure 2 is disposed in the area of intaglio motif 3 of document of value 1. The geometrical and color design of optically variable security element 2 can be adapted to intaglio motif 3. Depending on the execution of intaglio motif 3, optically variable structure 2 can also be integrated completely into said intaglio motif. However, the inventive security element can alternatively be disposed at any other place on document of value 1. It is especially advantageous to use inventive optically variable structure 2 in bank notes, as well as other papers of value such as shares, checks or the like. Labels or other elements for product protection can also be provided with such an optically variable structure. Optically variable structure 2 consists according to the shown embodiment of a first coating in the form of a print contrasting with the surface of the data carrier as well as an embossed structure and a second coating that likewise contrasts in color with the data carrier surface and is disposed congruent to the raised areas of the em- bossed structure. The various elements of optically variable structure 2 are combined with each other such that at least partial areas of the first coating are completely visible upon perpendicular viewing but concealed upon oblique viewing. This principle is made clear by the section along A-A shown in Fig. 2. First coating 4 consists of line screen 4, in the case shown here, and embossed structure 5 is also designed in the form of a line screen structure. Second ink layer 6 is disposed congruent to embossed structure 5, thus completely covering first coating 4. Upon per- pendicular viewing from viewing direction A, the viewer ideally recognizes only a colored surface whose color largely corresponds to the mixed color of first coating 4 and second coating 6. Upon oblique viewing from viewing direction B, the viewer is faced by the flank of embossed structure 5 that coincides with the printed lines of printed screen 4. The viewer therefore perceives from viewing direction B an almost uniform colored print in the color of the mixed color from first coating 4 and second coating 6. In viewing direction C the viewer is faced by the flanks of embossed struc- ture 5 that coincide with the particular gap of line screen 4, so that from this direction the viewer perceives a likewise uniformly colored surface in the color of second coat- ing 6. Embossed structure 5 and second coating 6 are preferably transferred to docu- ment of value 1 by the intaglio printing plate. This has the advantage that the security element can be produced simultaneously with intaglio motif 3 in one operation. For this purpose, both the negative of desired embossed structure 5 and the intaglio motif are engraved into the printing plate. During the printing operation the printing plate is filled with ink and then data carrier material 1 is pressed into the engraved areas of the plate and lastingly deformed. The high contact pressure causes embossing 5 to also be noticeable on the back of data carrier material 1. The printing plate can be inked with a uniform color for the printing operation so that second coating 6 and intaglio motif 3 have the same color. Different colors can also be used, however. Since translucent inks are preferably used for second coating 6, the viewer can recognize the mixed color of the two colors in the overlap area between first and sec- ond coatings 4, 6. Embossed structure 5 shown in Fig. 2 consists of directly adjoining triangular profiles when viewed in cross section. However, the triangular profiles can also be slightly spaced apart. The relative position of first coating 4 and second coating 6 or embossed structure 5 can also vary, as made clear by Figs. 3 to 5. Here, only the em- bossed profile and the relative position of coatings 4, 6 are shown. In Fig. 3 the triangular profiles of embossed structure 5 are spaced apart, which is indicated by connection bars 7. First coating 4 is disposed on one of the flanks of em- bossed structure 5 below second coating 6, as shown in Fig. 2. Connection bars 7 are coating-free, however, so that the data carrier surface is visible in this area. Fig. 4 shows a variant in which first coating 4 completely covers connection bars 7 and part of the flanks of embossed structure 5. In this example, second coating 6 covers first coating 4 only partly, so that first coating 4 is also visible in partial areas. Fig. 5 shows a further embodiment in which the relative position of embossed structure 5, first coating 4 and second coating 6 corresponds to the embodiment al- ready shown in Fig. 3. However, the raised areas of embossed structure 5 have differ- ent heights in this example. If embossed structure 5 and coating 6 are produced by ink- carrying intaglio printing, this means that more ink is transferred in the areas of the embossed structure with the higher raised areas. Due to the higher ink layer thickness in area 8 of embossing 5, partial areas 8 of embossing 5 appear in a darker color tone than partial areas 9 of embossing 5. In this way, additional information can be pro- duced in the optically variable element. However, such visually recognizable additional information can also be produced in other ways. If translucent printing inks are used, the additional information can also be represented by a higher ink layer thickness in certain areas of the printed image. Fig. 6 shows in cross section printing plate 30 for producing such additional in- formation. First printed image 31 is engraved into plate 30 with depth t1. Second printed image 32, which is superimposed on first printed image 31, is engraved into plate 30 with depth t2. Since the engraving for second printed image 32 is deeper than the engraving for first printed image 31, more ink is transferred in the area of printed image 32. When translucent printing inks are used, a darker color effect therefore re- sults in the area of printed image 32, and printed image 32 is recognizable against lighter printed image 31. According to this example, the two printed images 31, 32 form the second coating that is transferred to the document of value simultaneously with the embossed structure in the printing operation. Fig. 7 shows a further variant for producing additional information in the second coating. It again shows printing plate 30, into which a line with width b is milled. Said line is composed of different areas 33, 34 that differ in their depth and flank steepness. In the finished printed image said line shows different color effects along its length since the inking is different in areas 33, 34. If the line depth is too great, paper tears might occur during the embossing opera- tion. To therefore permit the same line width to be retained, it might therefore be nec- essary to make the line just as wide but less deep. If a milling tool is used for produc- ing the printing plate, it might therefore be necessary to produce the line by means of a narrower engraving tool that nevertheless produces the width of the desired engraved line by corresponding guidance of the milling tool. Fig. 8 shows a further embodiment of the inventive optically variable structure. In this example, the first coating consists of two crosswise disposed line screens 10, 11 that can also be designed in different colors. In the shown example, the lines of printed screen 11 are disposed on one of the flanks of embossed structure 5. This association emerges from the profile sketches at the lower edge of Fig. 8, which shows a detail of embossed structure 5 and coating 6 in cross section. Fig. 9 shows an embodiment of the inventive optically variable structure in which the first coating consists of one-sided screen 40. Said screen starts at straight baseline 41. Opposite line 42 of the screen element is of irregular design and can vary from screen element to screen element. This particular screen can be used to represent very well-contrasting halftone images. As explained above with reference to Fig. 8, said screen elements 40 preferably come to lie on the flanks of embossed structure 5 and are covered by second coating 6. Fig. 10 shows a top view of the basic structure of inventive optically variable structure 2. It consists of the first coating in the form of line screen 4 with a constant screen ruling, the line screen consisting of spaced-apart printed lines. Embossed struc- ture 5 is disposed in overlap with print 4, being indicated only by the dash-lined frame for clarity's sake. Shown embossed structure 5 is subdivided into six partial areas 50, 51, 52, 53, 54, 55 where partial embossed structures are disposed, being omitted from the drawing as mentioned above. The second coating, which is disposed congruent to the raised areas of the partial embossed structures, is not shown either. Partial areas 50, 51, 52, 53, 54, 55 are directly adjacent here and form a two-dimensional matrix. De- pending on the embodiment, said matrix can have n partial areas in the vertical direc- tion and m partial areas in the horizontal direction, where n, m = 1, preferably n, m = 2. In the shown example, n = 3 and m = 2. A second coating, which is likewise omitted from the drawing, is disposed congruent to the raised areas of embossed structure 5 in this example as well. The relative position of the partial embossed structures and line screen 4 varies within embossed structure 5 from partial area to partial area, so that partial areas 50, 51, 52, 53, 54, 55 differ in their color, color tone or brightness and are thus visually recognizable as contrasting partial areas. Upon a change of viewing angle, the color and light/dark impressions of the partial areas vary. This impression is strengthened by superimposed second coating 6. Fig. 11 schematically shows a further special embodiment of embossed structure 5. It is composed of partial areas 50, 51, 52, 53, 54, 55 where different partial em- bossed structures 20, 21, 22, 23, 24, 25 are disposed. The sloping lines in Fig. 11 indi- cate the course and arrangement of particular partial embossed structure 20, 21, 22, 23, 24, 25. The shown lines mark the valleys of the embossed structure, as is made clear by the sketch in the left area under embossed structure 5, which shows partial em- bossed structure 23 in cross section. For clarity's sake, the zeniths of partial embossed structures 20, 21, 22, 23, 24, 25 have not been shown with lines in the figures. All partial embossed structures 20, 21, 22, 23, 24, 25 have same screen ruling a. However, pairs of adjoining partial embossed structures 20, 21, 22, 23, 24, 25 are mu- tually offset. In the shown example, the offset is preferably a fraction 1/x of screen ruling a. Preferably, a pair of adjacent partial embossed structures is mutually offset by one third of screen ruling a. The first coating has been omitted in Fig. 11 for clarity's sake. Since the arrangement of the partial embossed structures and congruently dis- posed second coating varies from partial area to partial area, however, the relative po- sition between the first coating and particular partial embossed screen 20, 21, 22, 23, 24, 25 also varies accordingly. This produces frequently changing light/dark contrasts and changing color effects that visually stand out clearly and are well recognizable. If the offset is selected for example so that the partial embossed structures recur within embossed structure 5, a plurality of partial areas show the same appearance from one viewing angle. However, partial embossed structures 20, 21, 22, 23, 24, 25 of inven- tive embossed structure 5 need not be fundamentally offset by a fraction of screen rul- ing a. Any other offset is equally conceivable. Also, not all partial embossed structures 20, 21, 22, 23, 24, 25 need be mutually offset. In some circumstances it is sufficient if only two of partial areas 50, 51, 52, 53, 54, 55 are provided with mutually offset par- tial embossed structures 20, 21, 22, 23, 24, 25. The latter also need not necessarily be directly adjacent. Likewise, single partial areas 50, 51, 52, 53, 54, 55 can be provided with partial embossed structures 20, 21, 22, 23, 24, 25 with different screen ruling a. The extending direction of single partial embossed structures 20, 21, 22, 23, 24, 25 can also vary with respect to the extending direction of adjacent partial embossed struc- tures 20, 21, 22, 23, 24, 25. For example, partial embossed structure 20 can be dis- posed at an angle of 90° to partial embossed structure 21. In the shown examples, the first coating was always applied first and then em- bossing 5 or second coating 6. Alternatively, it is of course also possible to first apply the embossed structure and the second coating and then print the first coating on the second coating. We claim: 1. A data carrier with an optically variable structure having an embossed structure with raised areas and a first coating contrasting with the surface of the data carrier and provided only in cer- tain areas, the embossed structure and the coating being so combined that at least parts of the coating are completely visible upon perpendicular viewing but concealed upon oblique viewing so that a tilt effect arises upon alternate perpendicular and oblique viewing, and the optically variable structure having at least in partial areas a second coating disposed in overlap with the first coating at least in partial areas, characterized in that the second coating likewise contrasts with the data carrier surface and at least one of the coatings comprises at least partly, translucent inks, characterized in that the first coating is a printed line screen structure with a constant screen ruling and thickened areas at least in certain areas and only on one side. 2. A data carrier as claimed in claim 1, wherein the second coating is disposed congruent to at least parts of the raised areas of the embossed structure. 3. A data carrier as claimed in claim 2, wherein the data carrier has an intaglio motif. 4. A data carrier as claimed in claim 3, wherein at least parts of the embossed structure are disposed in the area of the intaglio motif. 5. A data carrier as claimed in claim 3, wherein the second coating has the same color as the intaglio motif. 6. A data carrier as claimed in claim 3, wherein the second coating is part of the intaglio mo- tif. 7. A data carrier as claimed in claim 1, wherein the second coating has a color contrasting with the first coating. 8. A data carrier as claimed in claim 1, wherein the color used for the first coating has a complementary contrast with the color of the second coating. 9. A data carrier as claimed in claim 1, wherein the first and second coatings are disposed at least partly in overlap. 10. A data carrier as claimed claim 1, wherein the optically variable structure has a metallic background layer. 11. A data carrier as claimed in claim 1, wherein at least one of the first or second coat- ing has machine-readable properties at least in certain areas. 12. A data carrier as claimed in claim 11, wherein at least one of the first and/or second coating has magnetic, electrically conductive or luminescent properties. 13. A data carrier as claimed in claim 1, wherein the optically variable structure is su- perimposed or underlaid with an additional transparent optically variable layer or a foil element. 14. A data carrier as claimed in claim 1, wherein one of the coatings is of multicolor design. 15. A data carrier as claimed in claim 1, wherein the line screen comprises colored, spaced-apart lines or colored, directly adjoining lines. 16. A data carrier as claimed in claim 1, wherein the line screen represents a halftone image. 17. A data carrier as claimed in claim 1, wherein the embossed structure is an embossed screen structure. 18. A data carrier as claimed in claim 1, wherein the embossed structure is executed as a line screen with a constant screen ruling. 19. A data carrier as claimed in claim 1, wherein the embossed structure has a varying screen ruling in certain areas. 20. A data carrier as claimed in claim 1, wherein the embossed structure and the second coating are executed as colored intaglio prints. 21. A data carrier as claimed in claims 1, wherein the first coating is a dark line screen and the second coating is present in the form of a light, colored line screen. 22. A data carrier as claimed in claim 1, wherein the embossed structure has raised areas of different height. 23. A data carrier as claimed in claim 1, wherein the embossed structure and the first coating have the same screen ruling. 24. A data carrier as claimed in claim 1, wherein the embossed structure is subdivided into partial areas where different partial embossed structures are provided. 25. A data carrier as claimed claim 24, wherein the partial areas form a two-dimension- al matrix having m partial areas in the horizontal direction and n partial areas in the vertic- al direction, where m, n = 1, preferably m, n=2. 26. A data carrier as claimed in claim 24, wherein the partial embossed structures in at least two adjoining partial areas are disposed offset by a fraction, in particular one third, of the screen ruling. 27. A data carrier as claimed in claim 24, wherein at least the partial embossed struc- tures of one partial area have an unembossed edge contour. 28. A data carrier as claimed in claim 1, wherein the data carrier is a paper of value. 29. A method for producing a data carrier with an optically variable structure having an embossed structure with raised areas and a first coating contrasting with the surface of the data carrier and applied to the data carrier only in certain areas, the embossed structure and the coating being so combined that at least parts of the coating are completely visible upon perpendicular viewing but concealed upon oblique viewing so that a tilt effect arises upon alternate perpendicular and oblique viewing, characterized by the following steps: applying the first coating to the data carrier only in certain areas, wherein the first coating is a printed line screen structure with a constant ruling and thickened areas at least in certain areas and only on one side, embossing the embossed structure in the data carrier by means of an embossing tool, whereby with the embossing a second coating comprising, at least partly, translucent inks is transferred to the data carrier in overlap with the first coating at least in par- tial areas, whereby a color likewise contrasting with the surface of the data carrier is selected for the second coating, and the transferring of the second coating to the data carrier is done con- gruently to at least parts of the raised areas of the embossed structure. 30. A method as claimed in claim 29, wherein the data carrier is provided with an in- taglio motif and at least parts of the embossed structure are disposed in the area of the in- taglio motif. 31. A method as claimed in claim 29, wherein the first coating is produced by the offset process. 32. A method as claimed in claim 29, wherein the embossed structure and the second coating are produced by ink-carrying intaglio printing. 33. A method as claimed in claim 32, wherein the second coating is executed as a color split. 34. A method as claimed in claim 29, wherein the first coating is applied first, and in a second step the embossed structure and the second coating are transferred simultaneously. 35. The data carrier as claimed in claim 28, wherein the paper of value is a bank note.

Full Text

This invention relates to a data carrier with an optically variable structure having
an embossed structure with raised areas and a first coating contrasting with the surface
of the data carrier, the embossed structure and the coating being so combined that at
least parts of the coating are completely visible upon perpendicular viewing but con-
cealed upon oblique viewing so that a tilt effect arises upon alternate perpendicular
and oblique viewing. The invention further relates to a method for producing such a
data carrier.
It has been known for some time to equip data carriers, such as bank notes, pa-
pers of value, credit cards or ID cards or the like, with optically variable security ele-
ments, in particular optically variable diffraction structures such as holograms. Protec-
tion from forgery by holograms is based on the different optical impression of said
holograms that occurs upon a change of viewing angle relative to trie hologram. Said
optically variable impression cannot be rendered by copying machines since copying
machines only render the appearance of the hologram from a certain viewing angle. A
data carrier with such a hologram is known for example from EP 0 440 045 A2. This
print proposes applying the hologram to the data carrier as a prefabricated element or
as an embossing in a lacquer layer applied to the data carrier.
However, there are other optically variable security elements that can be pro-
vided on a data carrier. Thus, it is known for example from CA 1 019 012 to provide a
bank note in a partial area of its surface with a parallel printed line pattern. To produce
the optically variable effect, a line structure is additionally embossed into the data car-
rier in the area of the printed line pattern so as to form flanks visible only at certain
viewing angles. Selectively disposing the printed line pattern on like-oriented flanks of
the embossed line structure causes the line pattern to be visible upon oblique viewing
of the flanks provided with the lines. Upon oblique viewing of the rear side of the
flanks the line pattern is not recognizable.
The antiforgery effect of such embossed optically variable security elements can
be improved further if additional visually recognizable effects are produced by selec-
tively changing the line pattern or embossed structure. Examples of such additional
effects are described in WO 97/17211 and WO 02/20280.
The optically variable effect of the latter known security elements arises funda-
mentally from the combination of a print with a blind embossing that is preferably
produced by intaglio printing. Blind embossing has the disadvantage that it cannot be
integrated into a colored intaglio image but can only be used as an isolated security
feature. This is because a relatively great distance between the blind embossing areas
and the ink-carrying areas is required to make sure that absolutely no ink gets into the
blind embossing depressions when the intaglio printing plate is inked.
The invention is therefore based on the problem of proposing a data carrier with
an optically variable security element of the abovementioned kind that can be inte-
grated into a printed image.
This problem is solved by the features of the independent claims. Developments
are the subject matter of the subclaims.
The invention is based on the finding that the optically variable effect of the se-
curity element is retained if an ink-carrying embossing is used instead of the blind em-
bossing. That is, the optically variable structure has at least in partial areas a second
coating likewise contrasting with the data carrier surface and disposed congruent to the
raised areas of the embossed structure. The second coating offers the advantage of sta-
bilizing the embossed structure without an additional printing operation.
Moreover, the inventive security element has the advantage that it can be inte-
grated into an intaglio motif and thus into the representational and color design of the
main motif.
Intaglio printing is characterized in that linear depressions are provided in the
printing plates to produce a printed image. Areal representations are also produced by
closely adjacent engraved lines, the individual engraved lines normally being fractions
of a millimeter wide.
For the printing operation the engraved lines of the plate are filled with ink. Sur-
plus ink is removed from the plate with the help of a wiping cylinder or doctor blade
such that the engraved lines are filled with ink up to the edge. During the printing op-
eration the data carrier to be printed, normally paper, is finally pressed onto the plate
with high pressure by means of a pressure cylinder having an elastic surface. The data
carrier is thereby pressed into the ink-filled engraved lines of the plate, thus coming in
contact with the ink. When the data carrier is detached it pulls the ink out of the de-
pressions of the engraved lines. The thus produced printed image has printed lines that
vary in ink layer thickness depending on the depth of engraving. The data carrier is
pressed into the depressions of the plate so strongly that it not only receives ink from
the depressions but is also simultaneously embossed.
When translucent inks are used in intaglio printing, light color tones are obtained
if a white data carrier is printed with thin ink layers, and darker color tones if printed
with thick ink layers. This effect can also be utilized within the scope of the invention
to produce different color effects and increase the contrast of the tilt effect. Likewise,
it is possible to combine translucent and nontranslucent inks.
The inventive optically variable structure can therefore be integrated into the
printing plate of an intaglio motif in a very simple way by providing the embossed
structure likewise in the form of depressions in the plate. During the printing operation
the depressions belonging to the embossed structure are filled with an ink having for
example the same color as the intaglio motif to be printed. This ink layer, which is
transferred to the data carrier with the embossing operation, forms the inventive sec-
ond coating disposed congruent to the raised areas of the embossed structure.
It is not necessary for the total embossed structure to be inked with this color.
Only partial areas of the embossed structure can also be provided with a color. Alter-
natively, it is also possible to provide the embossed structure with different colors or a
color flow. Such a color flow can be produced via a color split whereby the printing
plate is accordingly inked by means of single color stencils. Preferably, the color of the
second coating is integrated into the color design of the intaglio motif.
The color split and a corresponding choice of printing inks employed are used se-
lectively here to control the contrast of the optically variable structure.
The color split can also be used to make parts of the optically variable structure
machine-readable by adding at least one feature substance, such as a luminescent sub-
stance, magnetic substance or electrically conductive substance, to at least one of the
inks. Different parts of the optically variable structure can also be provided with dif-
ferent feature substances. Alternatively, the total optically variable structure can also
be equipped with a uniform machine-readable property.
The optically variable structure can be directly adjacent to the intaglio motif or
else be part of the steel intaglio motif.
Since such intaglio motifs are primarily applied in security printing, the inventive
data carrier is preferably a paper of value, in particular a bank note. The paper of value
can be a security paper made of cotton fibers, a paper containing synthetic fibers
and/or chemical pulp, or consist of pure plastic foils. Such a paper of value can also be
used advantageously for protecting any products and goods.
The second coating disposed in the area of the embossed structure can moreover
have a color contrasting with the first coating and be disposed at least in partial over-
lap with the first coating. Further, one of the coatings can have machine-readable
properties at least in certain areas. These may be for example magnetic, electrically
conductive or luminescent properties. Finally, the data carrier can have a metallic
background layer in the area of the optically variable structure.
The embossed structure is preferably executed as a screen structure. It can be tri-
angular, but also trapezoidal, sinusoidal, semicircular or another shape. Preferably, the
embossed structure is executed as a line screen with a constant screen ruling. In some
embodiments, however, it can also be expedient to use different screen rulings. For
example, the screen ruling can increase continuously in the edge area of the optically
variable structure so that the embossed structure quasi tapers out. The same effect can
be obtained by a continuous reduction of line width with constant or increasing screen
ruling. In this edge area the first coating can be adapted in accordance with the em-
bossed structure or be completely lacking.
Further effects can be obtained if the flank angles vary within a line of the em-
bossed structure executed as a line screen.
To better bring out the optically variable effects, the embossed structure can be
subdivided into partial areas where different partial embossed structures are provided,
as described in WO 02/20280. The disclosure of this print is incorporated in the pres-
ent invention by reference.
The partial areas preferably form a two-dimensional matrix having m partial ar-
eas in the horizontal direction and n partial areas in the vertical direction, where m, n =
1, preferably m,n = 2. The partial embossed structures in at least two adjoining partial
areas are disposed mutually offset by a fraction, in particular one third, of the screen
ruling.
The first coating is preferably a print likewise formed as a screen structure,
whereby the individual screen elements can be designed at will. However, a line
screen, with a constant screen ruling is preferably used. According to a preferred em-
bodiment, said line screen consists of printed lines of any desired color design. The
print is done by any desired printing process, such as offset or screen printing. Any
desired indirect printing processes, such as indirect letterpress, can also be applied.
The methods moreover make it possible to provide the first coating with a color flow,
a so-called "rainbow blend."
Printed screen and embossed structure are adjusted to each other, preferably such
that the width of the printed screen lines is somewhat smaller than the length of the
flanks of the embossed structure lines and that they extend parallel or largely parallel.
Printed screen and embossed structure need not necessarily extend in a straight line,
they can instead also be designed in the form of wavy lines, etc. The line widths are
between 25 microns and 300 microns, preferably between 55 microns and 150 mi-
crons. If the line screen is composed of printed, spaced-apart lines, a ratio of about 1 :1
is preferably selected for the ratio of printed to unprinted areas. If a line width in the
order of magnitude of about 100 microns is additionally selected, the lines can virtu-
ally no longer be resolved by the eye and a homogeneous color effect arises. That is,
the line screen is visually perceived only as a homogeneous colored surface. Addition-
ally, the lines can be executed thicker in certain areas and thus represent for example a
halftone image or another motif. Preferably, the lines only have thickened areas on one
side. This likewise leads to stronger contrast. Alternatively, the lines can have gaps.to
produce an additional visually recognizable pattern. The first coating and/or the em-
bossed structure can also be executed so as to repeat the content of other information
present on the document of value to make comparison possible.
Quite generally it is to be underlined that the color design of the security element
can be adjusted at will by a corresponding color choice of first and second coatings,
since the mixture of the two colors is always perceived at least in a top view. Likewise,
the information perceptible from different viewing angles can be adjusted by a corre-
sponding choice of parameters, such as color, line thickness and line modulation of the
first coating and flank angle, flank height and flank modulation of the embossed struc-
ture.
Rasterization of the print can be dispensed with if optically variable inks are
used, i.e. inks having different optical effects dependent on the angle of vision. These
may be high-gloss, e.g. metallic, layers or else inks that change their color effect them-
selves in angle-dependent fashion, as is the case for example with liquid crystal pig-
ment inks.
However, an inventive optically variable structure with a rasterized first coating
can also be additionally underlaid or covered with an optically variable printed image.
This is preferably done with printing inks having interference layer and/or liquid crys-
tal pigments. An additional metallic background is also conceivable. The printed im-
age can be executed to be positive or negative. The use of liquid crystals additionally
provides elevated protection from forgery since the printed image in this case has
light-polarizing properties that can be read by machine. This holds in particular when
the printed image is composed of partial printed images, with liquid crystals having
different polarization properties being used for the partial printed images.
The inventive optically variable structure can be underlaid or covered, not with
an additional printed image, but with a foil element, such as a diffraction structure em-
bossed into a lacquer layer. Here, any desired layer structures and types of foil ele-
ments can be used, such as real holograms, lattice structures, volume holograms that
are executed to be transparent, semitransparent or opaque.
According to a preferred embodiment, the inventive optically variable structure
consists of a print in the form of a printed line screen, a first color and an embossed
structure superimposed on said line screen and likewise executed in linear fashion
whose raised areas are provided with a further color contrasting with said first color.
Said second color is preferably produced by means of translucent printing inks that
have a certain transparency so that the color of the first coating shines through said
color and the viewer thus perceives a mixed color in the superimposed areas. Espe-
cially good effects are achieved if there is a complementary contrast between the first
and second colors.
When viewing said optically variable structure perpendicular to the data carrier
surface, the viewer ideally recognizes only a uniform color effect. When the data car-
rier is tilted or the viewing angle changed, parts of the first and/or second coating are
concealed by the embossed structure, so that in certain areas the color effect of the first
or second coating or of the mixed color of the two coatings predominates and thus
variable color effects arise.
This interplay of colors appears all the more clearly the better-contrasting the
colors of the two coatings are. For example, a dark, e.g. black, line screen can be com-
bined with a well-contrasting colored intaglio print with translucent inks, such as yel-
low or other light color tones. The first coating in the form of a black line screen is
preferably printed on here by the offset process.
Alternatively, a further preferably all-over ink layer can be disposed under the
first preferably screenlike coating. Said layer serves to stabilize the paper in the area of
the security element and permits sharper edges in the area of the embossed structure.
Said layer can be executed as a primer or colored lacquer layer or else contribute addi-
tionally to the color design of the security element if said layer has a color contrasting
with the first coating. One can use conventional printing inks or else special-effect
inks, such as luminescent inks or printing inks containing interference or liquid crystal
pigments.
Finally, additional information can also be incorporated by designing the em-
bossed structure and/or first coating accordingly. For example, the raised areas of the
embossed structure can have different heights. If the embossed structure is produced
by intaglio printing, this means that the engraving depths for the embossed structure
are selected differently. The areas of lower engraving depth are filled with less ink in
the printing or embossing operation and produce areas with a lighter color tone if
translucent inks are used. In this way the inventive second coating can be used to pro-
duce additional information visually recognizable at all viewing angles. Due to the
different embossing heights, however, a change of viewing angle yields additional op-
tically variable effects that are caused by the relative position of the first and second
coatings as well as the embossed structure and the interplay thereof.
The additional information can also be emphasized by an unembossed edge con-
tour, as already described in WO 02/20280. Alternatively, the edge contour can also be
provided with the second coating and the embossed structure according to the inven-
tion.
As mentioned above several times, the inventive optically variable security ele-
ment is preferably produced in two printing operations. In a first printing operation,
preferably by the offset process or an indirect printing process, the first coating is
printed on the data carrier. In the second printing operation, which is preferably done
by intaglio according to the invention, the embossed structure and the second coating
are finally transferred to the data carrier simultaneously.
Similar optical effects can be achieved if the two coatings are printed on in regis-
ter to each other by offset and/or screen printing and this printed area is then provided
with a blind embossing likewise in register. All embodiments described within the
scope of the invention can be produced in this way. According to a special embodi-
ment, for example, a line screen in a first color can be applied and at least partly in
overlap therewith a second coating of translucent inks all over. In a last step, the total
printed area is provided with a blind embossing in the form of a line screen in register.
However, it is also possible to use the reverse order, providing first the embossed
structure and second coating on the data carrier and then the first coating.
Further embodiments and advantages of the invention will be explained with ref-
erence to the figures, in which:
Fig. 1 shows an inventive data carrier,
Fig. 2 shows a section along A - A in Fig. 1,
Fig. 3 shows a schematic representation of the relative position between the first
and second coatings of the inventive security element in a first embodiment,
Fig. 4 shows a schematic representation of the relative position between the first
and second coatings of the inventive security element according to a second embodi-
ment,
Fig. 5 shows a schematic representation of the relative position of the first and
second coatings of the inventive security element according to a third embodiment, the
embossed structure having raised areas of different heights,
Fig. 6 shows an inventive embossing mold in cross section for producing the em-
bossed structure with additional information,
Fig. 7. shows a further embodiment of the inventive embossing mold,
Fig. 8 shows a further variant of the inventive security element,
Fig. 9 shows a further variant of the inventive security element,
Fig. 10 shows a special embodiment of the inventive security element wherein
the embossed structure is present in the form of a matrix,
Fig. 11 shows a special embodiment of the embossed structure of the inventive
security element.
Fig. 1 shows inventive data carrier 1 with optically variable structure 2. Optically
variable structure 2 is a security feature that can be checked without aids and is used
optionally alongside further security features for checking the authenticity of the data
carrier. The further security features may be for example a security thread, watermark
or the like. As preferred within the scope of the invention, optically variable structure
2 is disposed in the area of intaglio motif 3 of document of value 1. The geometrical
and color design of optically variable security element 2 can be adapted to intaglio
motif 3. Depending on the execution of intaglio motif 3, optically variable structure 2
can also be integrated completely into said intaglio motif.
However, the inventive security element can alternatively be disposed at any
other place on document of value 1.
It is especially advantageous to use inventive optically variable structure 2 in
bank notes, as well as other papers of value such as shares, checks or the like. Labels
or other elements for product protection can also be provided with such an optically
variable structure.
Optically variable structure 2 consists according to the shown embodiment of a
first coating in the form of a print contrasting with the surface of the data carrier as
well as an embossed structure and a second coating that likewise contrasts in color
with the data carrier surface and is disposed congruent to the raised areas of the em-
bossed structure. The various elements of optically variable structure 2 are combined
with each other such that at least partial areas of the first coating are completely visible
upon perpendicular viewing but concealed upon oblique viewing.
This principle is made clear by the section along A-A shown in Fig. 2. First
coating 4 consists of line screen 4, in the case shown here, and embossed structure 5 is
also designed in the form of a line screen structure. Second ink layer 6 is disposed
congruent to embossed structure 5, thus completely covering first coating 4. Upon per-
pendicular viewing from viewing direction A, the viewer ideally recognizes only a
colored surface whose color largely corresponds to the mixed color of first coating 4
and second coating 6. Upon oblique viewing from viewing direction B, the viewer is
faced by the flank of embossed structure 5 that coincides with the printed lines of
printed screen 4. The viewer therefore perceives from viewing direction B an almost
uniform colored print in the color of the mixed color from first coating 4 and second
coating 6. In viewing direction C the viewer is faced by the flanks of embossed struc-
ture 5 that coincide with the particular gap of line screen 4, so that from this direction
the viewer perceives a likewise uniformly colored surface in the color of second coat-
ing 6.
Embossed structure 5 and second coating 6 are preferably transferred to docu-
ment of value 1 by the intaglio printing plate. This has the advantage that the security
element can be produced simultaneously with intaglio motif 3 in one operation. For
this purpose, both the negative of desired embossed structure 5 and the intaglio motif
are engraved into the printing plate. During the printing operation the printing plate is
filled with ink and then data carrier material 1 is pressed into the engraved areas of the
plate and lastingly deformed. The high contact pressure causes embossing 5 to also be
noticeable on the back of data carrier material 1.
The printing plate can be inked with a uniform color for the printing operation so
that second coating 6 and intaglio motif 3 have the same color. Different colors can
also be used, however.
Since translucent inks are preferably used for second coating 6, the viewer can
recognize the mixed color of the two colors in the overlap area between first and sec-
ond coatings 4, 6.
Embossed structure 5 shown in Fig. 2 consists of directly adjoining triangular
profiles when viewed in cross section. However, the triangular profiles can also be
slightly spaced apart. The relative position of first coating 4 and second coating 6 or
embossed structure 5 can also vary, as made clear by Figs. 3 to 5. Here, only the em-
bossed profile and the relative position of coatings 4, 6 are shown.
In Fig. 3 the triangular profiles of embossed structure 5 are spaced apart, which is
indicated by connection bars 7. First coating 4 is disposed on one of the flanks of em-
bossed structure 5 below second coating 6, as shown in Fig. 2. Connection bars 7 are
coating-free, however, so that the data carrier surface is visible in this area.
Fig. 4 shows a variant in which first coating 4 completely covers connection bars
7 and part of the flanks of embossed structure 5. In this example, second coating 6
covers first coating 4 only partly, so that first coating 4 is also visible in partial areas.
Fig. 5 shows a further embodiment in which the relative position of embossed
structure 5, first coating 4 and second coating 6 corresponds to the embodiment al-
ready shown in Fig. 3. However, the raised areas of embossed structure 5 have differ-
ent heights in this example. If embossed structure 5 and coating 6 are produced by ink-
carrying intaglio printing, this means that more ink is transferred in the areas of the
embossed structure with the higher raised areas. Due to the higher ink layer thickness
in area 8 of embossing 5, partial areas 8 of embossing 5 appear in a darker color tone
than partial areas 9 of embossing 5. In this way, additional information can be pro-
duced in the optically variable element.
However, such visually recognizable additional information can also be produced
in other ways. If translucent printing inks are used, the additional information can also
be represented by a higher ink layer thickness in certain areas of the printed image.
Fig. 6 shows in cross section printing plate 30 for producing such additional in-
formation. First printed image 31 is engraved into plate 30 with depth t1. Second
printed image 32, which is superimposed on first printed image 31, is engraved into
plate 30 with depth t2. Since the engraving for second printed image 32 is deeper than
the engraving for first printed image 31, more ink is transferred in the area of printed
image 32. When translucent printing inks are used, a darker color effect therefore re-
sults in the area of printed image 32, and printed image 32 is recognizable against
lighter printed image 31. According to this example, the two printed images 31, 32
form the second coating that is transferred to the document of value simultaneously
with the embossed structure in the printing operation.
Fig. 7 shows a further variant for producing additional information in the second
coating. It again shows printing plate 30, into which a line with width b is milled. Said
line is composed of different areas 33, 34 that differ in their depth and flank steepness.
In the finished printed image said line shows different color effects along its length
since the inking is different in areas 33, 34.
If the line depth is too great, paper tears might occur during the embossing opera-
tion. To therefore permit the same line width to be retained, it might therefore be nec-
essary to make the line just as wide but less deep. If a milling tool is used for produc-
ing the printing plate, it might therefore be necessary to produce the line by means of a
narrower engraving tool that nevertheless produces the width of the desired engraved
line by corresponding guidance of the milling tool.
Fig. 8 shows a further embodiment of the inventive optically variable structure.
In this example, the first coating consists of two crosswise disposed line screens 10, 11
that can also be designed in different colors. In the shown example, the lines of printed
screen 11 are disposed on one of the flanks of embossed structure 5. This association
emerges from the profile sketches at the lower edge of Fig. 8, which shows a detail of
embossed structure 5 and coating 6 in cross section.
Fig. 9 shows an embodiment of the inventive optically variable structure in
which the first coating consists of one-sided screen 40. Said screen starts at straight
baseline 41. Opposite line 42 of the screen element is of irregular design and can vary
from screen element to screen element. This particular screen can be used to represent
very well-contrasting halftone images. As explained above with reference to Fig. 8,
said screen elements 40 preferably come to lie on the flanks of embossed structure 5
and are covered by second coating 6.
Fig. 10 shows a top view of the basic structure of inventive optically variable
structure 2. It consists of the first coating in the form of line screen 4 with a constant
screen ruling, the line screen consisting of spaced-apart printed lines. Embossed struc-
ture 5 is disposed in overlap with print 4, being indicated only by the dash-lined frame
for clarity's sake. Shown embossed structure 5 is subdivided into six partial areas 50,
51, 52, 53, 54, 55 where partial embossed structures are disposed, being omitted from
the drawing as mentioned above. The second coating, which is disposed congruent to
the raised areas of the partial embossed structures, is not shown either. Partial areas 50,
51, 52, 53, 54, 55 are directly adjacent here and form a two-dimensional matrix. De-
pending on the embodiment, said matrix can have n partial areas in the vertical direc-
tion and m partial areas in the horizontal direction, where n, m = 1, preferably n, m = 2.
In the shown example, n = 3 and m = 2. A second coating, which is likewise omitted
from the drawing, is disposed congruent to the raised areas of embossed structure 5 in
this example as well.
The relative position of the partial embossed structures and line screen 4 varies
within embossed structure 5 from partial area to partial area, so that partial areas 50,
51, 52, 53, 54, 55 differ in their color, color tone or brightness and are thus visually
recognizable as contrasting partial areas. Upon a change of viewing angle, the color
and light/dark impressions of the partial areas vary. This impression is strengthened by
superimposed second coating 6.
Fig. 11 schematically shows a further special embodiment of embossed structure
5. It is composed of partial areas 50, 51, 52, 53, 54, 55 where different partial em-
bossed structures 20, 21, 22, 23, 24, 25 are disposed. The sloping lines in Fig. 11 indi-
cate the course and arrangement of particular partial embossed structure 20, 21, 22, 23,
24, 25. The shown lines mark the valleys of the embossed structure, as is made clear
by the sketch in the left area under embossed structure 5, which shows partial em-
bossed structure 23 in cross section. For clarity's sake, the zeniths of partial embossed
structures 20, 21, 22, 23, 24, 25 have not been shown with lines in the figures.
All partial embossed structures 20, 21, 22, 23, 24, 25 have same screen ruling a.
However, pairs of adjoining partial embossed structures 20, 21, 22, 23, 24, 25 are mu-
tually offset. In the shown example, the offset is preferably a fraction 1/x of screen
ruling a. Preferably, a pair of adjacent partial embossed structures is mutually offset by
one third of screen ruling a. The first coating has been omitted in Fig. 11 for clarity's
sake. Since the arrangement of the partial embossed structures and congruently dis-
posed second coating varies from partial area to partial area, however, the relative po-
sition between the first coating and particular partial embossed screen 20, 21, 22, 23,
24, 25 also varies accordingly. This produces frequently changing light/dark contrasts
and changing color effects that visually stand out clearly and are well recognizable. If
the offset is selected for example so that the partial embossed structures recur within
embossed structure 5, a plurality of partial areas show the same appearance from one
viewing angle. However, partial embossed structures 20, 21, 22, 23, 24, 25 of inven-
tive embossed structure 5 need not be fundamentally offset by a fraction of screen rul-
ing a. Any other offset is equally conceivable. Also, not all partial embossed structures
20, 21, 22, 23, 24, 25 need be mutually offset. In some circumstances it is sufficient if
only two of partial areas 50, 51, 52, 53, 54, 55 are provided with mutually offset par-
tial embossed structures 20, 21, 22, 23, 24, 25. The latter also need not necessarily be
directly adjacent. Likewise, single partial areas 50, 51, 52, 53, 54, 55 can be provided
with partial embossed structures 20, 21, 22, 23, 24, 25 with different screen ruling a.
The extending direction of single partial embossed structures 20, 21, 22, 23, 24, 25 can
also vary with respect to the extending direction of adjacent partial embossed struc-
tures 20, 21, 22, 23, 24, 25. For example, partial embossed structure 20 can be dis-
posed at an angle of 90° to partial embossed structure 21.
In the shown examples, the first coating was always applied first and then em-
bossing 5 or second coating 6. Alternatively, it is of course also possible to first apply
the embossed structure and the second coating and then print the first coating on the
second coating.
We claim:
1. A data carrier with an optically variable structure having an embossed structure with raised
areas and a first coating contrasting with the surface of the data carrier and provided only in cer-
tain areas, the embossed structure and the coating being so combined that at least parts of the
coating are completely visible upon perpendicular viewing but concealed upon oblique viewing
so that a tilt effect arises upon alternate perpendicular and oblique viewing, and the optically
variable structure having at least in partial areas a second coating disposed in overlap with the
first coating at least in partial areas, characterized in that the second coating likewise contrasts
with the data carrier surface and at least one of the coatings comprises at least partly, translucent
inks, characterized in that the first coating is a printed line screen structure with a constant
screen ruling and thickened areas at least in certain areas and only on one side.
2. A data carrier as claimed in claim 1, wherein the second coating is disposed congruent to at
least parts of the raised areas of the embossed structure.
3. A data carrier as claimed in claim 2, wherein the data carrier has an intaglio motif.
4. A data carrier as claimed in claim 3, wherein at least parts of the embossed structure are
disposed in the area of the intaglio motif.
5. A data carrier as claimed in claim 3, wherein the second coating has the same color as the
intaglio motif.
6. A data carrier as claimed in claim 3, wherein the second coating is part of the intaglio mo-
tif.
7. A data carrier as claimed in claim 1, wherein the second coating has a color contrasting
with the first coating.
8. A data carrier as claimed in claim 1, wherein the color used for the first coating has a
complementary contrast with the color of the second coating.
9. A data carrier as claimed in claim 1, wherein the first and second coatings are disposed at
least partly in overlap.
10. A data carrier as claimed claim 1, wherein the optically variable structure has a metallic
background layer.
11. A data carrier as claimed in claim 1, wherein at least one of the first or second coat-
ing has machine-readable properties at least in certain areas.
12. A data carrier as claimed in claim 11, wherein at least one of the first and/or second
coating has magnetic, electrically conductive or luminescent properties.
13. A data carrier as claimed in claim 1, wherein the optically variable structure is su-
perimposed or underlaid with an additional transparent optically variable layer or a foil
element.
14. A data carrier as claimed in claim 1, wherein one of the coatings is of multicolor
design.
15. A data carrier as claimed in claim 1, wherein the line screen comprises colored,
spaced-apart lines or colored, directly adjoining lines.
16. A data carrier as claimed in claim 1, wherein the line screen represents a halftone
image.
17. A data carrier as claimed in claim 1, wherein the embossed structure is an embossed
screen structure.
18. A data carrier as claimed in claim 1, wherein the embossed structure is executed as a
line screen with a constant screen ruling.
19. A data carrier as claimed in claim 1, wherein the embossed structure has a varying
screen ruling in certain areas.
20. A data carrier as claimed in claim 1, wherein the embossed structure and the second
coating are executed as colored intaglio prints.
21. A data carrier as claimed in claims 1, wherein the first coating is a dark line screen
and the second coating is present in the form of a light, colored line screen.
22. A data carrier as claimed in claim 1, wherein the embossed structure has raised areas
of different height.
23. A data carrier as claimed in claim 1, wherein the embossed structure and the first
coating have the same screen ruling.
24. A data carrier as claimed in claim 1, wherein the embossed structure is subdivided
into partial areas where different partial embossed structures are provided.
25. A data carrier as claimed claim 24, wherein the partial areas form a two-dimension-
al matrix having m partial areas in the horizontal direction and n partial areas in the vertic-
al direction, where m, n = 1, preferably m, n=2.
26. A data carrier as claimed in claim 24, wherein the partial embossed structures in at
least two adjoining partial areas are disposed offset by a fraction, in particular one third,
of the screen ruling.
27. A data carrier as claimed in claim 24, wherein at least the partial embossed struc-
tures of one partial area have an unembossed edge contour.
28. A data carrier as claimed in claim 1, wherein the data carrier is a paper of value.
29. A method for producing a data carrier with an optically variable structure having an
embossed structure with raised areas and a first coating contrasting with the surface of the
data carrier and applied to the data carrier only in certain areas, the embossed structure
and the coating being so combined that at least parts of the coating are completely visible
upon perpendicular viewing but concealed upon oblique viewing so that a tilt effect arises
upon alternate perpendicular and oblique viewing, characterized by the following steps:
applying the first coating to the data carrier only in certain areas, wherein the first
coating is a printed line screen structure with a constant ruling and thickened areas
at least in certain areas and only on one side,
embossing the embossed structure in the data carrier by means of an embossing tool,
whereby with the embossing a second coating comprising, at least partly, translucent
inks is transferred to the data carrier in overlap with the first coating at least in par-
tial areas,
whereby a color likewise contrasting with the surface of the data carrier is selected for the
second coating, and the transferring of the second coating to the data carrier is done con-
gruently to at least parts of the raised areas of the embossed structure.
30. A method as claimed in claim 29, wherein the data carrier is provided with an in-
taglio motif and at least parts of the embossed structure are disposed in the area of the in-
taglio motif.
31. A method as claimed in claim 29, wherein the first coating is produced by the offset
process.
32. A method as claimed in claim 29, wherein the embossed structure and the second
coating are produced by ink-carrying intaglio printing.
33. A method as claimed in claim 32, wherein the second coating is executed as a color
split.
34. A method as claimed in claim 29, wherein the first coating is applied first, and in a
second step the embossed structure and the second coating are transferred simultaneously.
35. The data carrier as claimed in claim 28, wherein the paper of value is a bank note.

Documents:

323-KOLNP-2005-ABSTRACT 1.1.pdf

323-kolnp-2005-abstract.pdf

323-kolnp-2005-assignment.pdf

323-KOLNP-2005-CANCELLED PAGES.pdf

323-KOLNP-2005-CLAIMS 1.1.pdf

323-kolnp-2005-claims.pdf

323-KOLNP-2005-CORRESPONDENCE 1.1.pdf

323-kolnp-2005-correspondence-1.3.pdf

323-KOLNP-2005-CORRESPONDENCE.1.2.pdf

323-kolnp-2005-correspondence.pdf

323-KOLNP-2005-DESCRIPTION (COMPLETE) 1.1.pdf

323-kolnp-2005-description (complete).pdf

323-KOLNP-2005-DRAWINGS 1.1.pdf

323-kolnp-2005-drawings.pdf

323-KOLNP-2005-EXAMINATION REPORT REPLY RECIEVED.pdf

323-kolnp-2005-examination report.pdf

323-KOLNP-2005-FORM 1.1.1.pdf

323-kolnp-2005-form 1.pdf

323-kolnp-2005-form 18-1.1.pdf

323-kolnp-2005-form 18.pdf

323-KOLNP-2005-FORM 2.pdf

323-kolnp-2005-form 3-1.2.pdf

323-KOLNP-2005-FORM 3.1.1.pdf

323-kolnp-2005-form 3.pdf

323-kolnp-2005-form 5-1.1.pdf

323-kolnp-2005-form 5.pdf

323-KOLNP-2005-FORM-27.pdf

323-kolnp-2005-gpa-1.1.pdf

323-kolnp-2005-gpa.pdf

323-kolnp-2005-granted-abstract.pdf

323-KOLNP-2005-GRANTED-CLAIMS1.1.pdf

323-kolnp-2005-granted-description (complete).pdf

323-kolnp-2005-granted-drawings.pdf

323-kolnp-2005-granted-form 1.pdf

323-kolnp-2005-granted-form 2.pdf

323-KOLNP-2005-GRANTED-SPECIFICATION1.1.pdf

323-KOLNP-2005-OTHERS-1.1.pdf

323-kolnp-2005-others.pdf

323-KOLNP-2005-PETITION UNDER RULE 137.pdf

323-kolnp-2005-reply to examination report.pdf

323-kolnp-2005-specification.pdf

323-KOLNP-2005-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

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Patent Number

250988

Indian Patent Application Number

323/KOLNP/2005

PG Journal Number

07/2012

Publication Date

17-Feb-2012

Grant Date

15-Feb-2012

Date of Filing

02-Mar-2005

Name of Patentee

GIESECKE & DEVRIENT GMBH

Applicant Address

PRINZREGENTENSTRASSE 159, 81677 MUNCHEN

Inventors:

#	Inventor's Name	Inventor's Address
1	FRANZ, PETER	TANNENWEG 15, 85567 BRUCK
2	ADAMCZYCK, ROGER	MUHLBACHSTRASSE 10, 84424 ISEN

PCT International Classification Number

B42D 15/00

PCT International Application Number

PCT/EP2003/008891

PCT International Filing date

2003-08-11

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102 43 863.3	2002-09-20	Germany
2	102 37 642.5	2002-08-13	Germany