COUNTERFEIT-PROTECTED DATA CARRIER AND METHOD FOR MANUFACTURING SAME

Abstract

 The invention relates to counterfeit-protected data carriers and methods for protecting printed products against counterfeit. Data carrier has a transparent portion with graphic elements disposed on both sides thereof in the form of a high resolution line screen, said graphic elements forming a periodic structure, wherein the elements are mutually arranged such that they form an image which is hidden when viewed in reflected light and visible when viewed in transmitted light; furthermore, when viewed from a different direction in transmitted light the image changes from positive to negative and vice versa, and/or the color of the image changes completely or partially, and/or the effect of motion of monochrome or multi-colored moire fringes appears. Method for manufacturing the data carrier comprises applying graphic elements to both sides of a transparent portion of the carrier by printing. The data carrier retains its flatness after printing. The invention enhances the security of products, provides a novel optically variable effect and/or a motion effect, as well as improves the production effectiveness and reduces the cost of the security element.

Description

Technical Field

[0001] The invention relates to counterfeit-protected data carriers and methods for protecting against counterfeit printed products, such as security papers, bank notes, identity documents, both paper and polymer based.

Description of Prior Art

[0002] A method for manufacturing security papers disclosed in DE 3208204 A1 relates to the protection against unauthorized copying by offset printing. Data carrier is a transparent paper or another transparent carrier material with periodic or almost periodic patterns consisting of dots or lines applied to both sides thereof. In application, images on the front and reverse sides of the carrier are precisely registered using two-sided printing machines. Therefore, this method provides for a periodic structure of lines, which has the appearance of fine lines when the structure is properly correlated in transmitted light, but moire patterns appear at a slight displacement of the structure in a case of forgery.

[0003] The disadvantage of this approach is that the elements on the front and reverse sides must be precisely registered, and this fact complicates the manufacturing process as it necessitates the use of only the double-sided printing equipment and increases the likelihood of defective products. It should also be noted that the use of double-sided printing due to process peculiarities makes infeasible the use of images with a line width less than 40 µm.

[0004] A similar approach is disclosed in US 6,494,491 B1, 17.12.2002, wherein to provide a latent image the graphical elements forming a security element are arranged such that part of the elements are slightly displaced with respect to each other. Latent image can be recovered using a transparent material with a grid applied thereon, said grid corresponding to the position of non-displaced graphical elements. When the material is superimposed on the carrier, the grid elements cover the non-displaced graphical elements of the carrier and the latent image appears as positive. When the transparent material is superimposed with a displacement such that the grid elements cover displaced elements, the latent image appears as negative.

[0005] The disadvantage of this approach is the necessity to register the transparent material with the printed portion without skew, which complicates identification of the security element by an unskilled user.

[0006] The closest prior art is RU 2386544 C1, 20.04.2010, which discloses a security element for printed products, comprising a multilayer transparent polymer film with a first screened image formed on the upper surface of the upper layer of the film, having a resolution of the same order of magnitude as the film thickness, and a second screened image formed on the lower surface of one of underlying layers of the polymeric film and/or on the surface of the product being protected, on which the security element is positioned, and the second screened image is positioned such that when viewed in reflected light at different angles or in transmitted light, the image gradually changes from positive to negative or vice versa, wherein the first and second screened image is transparent and/or translucent, and/or reflective and/or luminescent, and/or embossed. A method of manufacturing the security element comprises applying images to the surface of film layers by methods of local carbonization and/or laser beam engraving in surface layers of the film having a thickness of 1-10 µm, and/or by thermal diffusion copying methods.

[0007] The disadvantage of this approach is the restrictions on the method of forming the screen elements; in particular, such elements cannot be formed without the use of laser treatment, which significantly limits the range of application in protected printed products.

Summary of the Invention

[0008] The object of the invention is to enhance the security of products through the use of high-resolution images that are infeasible by digital printing devices and commercial printing, and to provide a novel variable optical effect and/or motion effect, as well as to improve the production effectiveness and reduce the cost of the security element owing to forming the screen by printing.

[0009] The object is attained owing to the features set forth the claims. Preferred embodiments of the inventive data carrier and methods of manufacturing are defined in dependent claims.

[0010] A counterfeit-protected data carrier has at least one transparent portion with graphic elements disposed on both sides thereof in the form of a high-resolution line screen, the graphic elements forming a high-resolution periodic structure, wherein according to the invention the graphic elements are formed by printing, and the data carrier retains its flatness after printing; the thickness of the applied ink layer is in the range of from 3 to 10 µm, and the elements are mutually arranged such that they form an image which is hidden when viewed in reflected light and visible when viewed in transmitted light; furthermore, when viewed from a different direction in transmitted light, the image changes from positive to negative and vice versa, and/or the color of the image changes completely or partially, and/or the effect of motion of monochrome or multi-colored moire fringes appears. The width of the graphical elements and the clearance between them should be less than or equal to the thickness of the carrier, this dictates the use of high-resolution graphic elements and images since the thickness of the transparent portion of the data carrier can range from 10 to 40 µm.

[0011] The transparent portion of the data carrier can be formed by a single layer or a multilayer polymer film, transparent or partially dyed in the bulk or on the surface; or a specially impregnated paper; or a filigree watermark.

[0012] The image can be formed by broken or curved lines, or dots, or strokes, or graphic primitives, or a combination thereof.

[0013] A method of manufacturing a counterfeit-protected data carrier comprises applying graphic elements in the form of a line screen to at least one transparent portion of the carrier to form a periodic structure, wherein according to the invention the graphic elements are applied by printing to one or both sides of the carrier, and the elements are mutually arranged such that they form an image exhibiting an optically variable effect.

[0014] The graphic elements are applied by intaglio printing provided the following conditions are observed: the depth of engraving hatch should not exceed 14 µm and the width of the graphic elements should match the order of magnitude of the thickness of the data carrier. The resulting data carrier must retain its flatness, and the thickness of the ink layer should be in the range of from 3 to 10 µm.

[0015] In particular, graphic elements on one or both sides of the carrier can be formed by a laser method of partial removal of a pre-applied metal layer, respectively, from one or both sides of the carrier.

Brief Description of the Drawings

[0016] List of Figures

Fig. 1 shows a structure of a transparent portion in the manufacturing process.

Figs. 2-3 show an arrangement of graphical elements on the front and reverse sides of the transparent portion.

Fig. 4 shows an embodiment of a structure of a transparent portion in the manufacturing process, and a process of formation of a hidden image.

Figs. 5-8 show how an image is obtained when observing the carrier in transmitted light at various angles of inclination.

Fig. 9 shows an embodiment of a structure of a transparent portion in the manufacturing process using special inks.

Fig. 10 shows a structure of a transparent portion in the manufacturing process.

[0017] Fig. 1 shows an embodiment of a structure of a transparent portion of a carrier produced by a first method. Graphic elements 2, 3 are applied to a transparent portion of a carrier 1 by printing.

[0018] Fig. 2 shows an embodiment of an image on one side of data carrier, containing a background image. The image consists of equally spaced straight lines having a constant width.

[0019] Fig. 3 shows an embodiment of an image on one side of a data carrier. It consists of straight lines having a constant width. In contrast to Fig. 2, part of the lines forming a background image 4 and part of the lines forming a hidden latent image 5 are displaced relative to each other.

[0020] Fig. 4 shows an embodiment of a structure of a transparent portion of the carrier produced by the first method, and how a negative image can be obtained when the carrier is viewed in transmitted light at appropriate angle to the surface of the carrier.

[0021] Part of graphic elements 5 on the front side of the carrier are displaced relative to the other elements forming the background 4. When viewing the carrier in transmitted light at angle α to the surface of the carrier, the observer sees a dark background 4a and a bright image 5a.

[0022] Fig. 5 shows the resulting image in which additional information is visible when the carrier is viewed in transmitted light, and the angle of viewing is such that elements on the reverse side overlap clearances between elements on the front side positioned without displacement, thereby forming a bright image on a dark background.

[0023] Fig. 6 shows the resulting image, in which the angle of inclination of the carrier ensures overlapping by the reverse side elements the clearances between the front side elements positioned with displacement, which leads to formation of a dark image on a bright background.

[0024] Figs. 7-8 show the resulting image at different angles, in which graphical elements of the front and reverse sides are angled relative to each other, which leads to formation of a moire pattern. Changing the angle of inclination of the carrier provides motion of the moire pattern over the element.

[0025] Fig. 9 shows an image obtained under UV or IR light.

[0026] Fig. 10 shows an embodiment of a structure of a transparent portion of the carrier 6, produced by a third method. Graphical elements are applied to the front side 8 by printing, while printing on the reverse side 7 is omitted; the graphical elements are produced by partial demetallization within the transparent material.

Best Embodiments of the Invention

[0027] The invention is illustrated by the following examples.

Example 1 (Figs. 1, 2, 3, 4, 5, 6, 7, 8, 9).

[0028] A counterfeit-protected data carrier (Fig. 1) comprises a transparent portion 1, to which graphic elements 2 and 3 are applied by printing. Graphic elements 2 comprise a background image (Fig. 2), and graphic elements 3 applied to the other side comprise a hidden image 4 and a background image 5 (Fig. 3).

[0029] When viewing the carrier in reflected light a uniformly colored field is observed. When viewing the same in transmitted light, as shown in Fig. 4, at different angles, the image changes from positive to negative and vice versa (Figs. 5 and 6).

[0030] If graphical elements (Fig. 2, 3) are applied at an angle to each other, when the carrier is viewed in transmitted light at different angles, motion of moire fringes can be observed as shown in Figs. 7 and 8.

[0031] If graphic elements are printed on the front or reverse side (Figs. 2 and 3) using a special ink, coloring can be observed under UV or IR light in at least a portion of the element, as shown in Fig. 9.

Example 2 (Fig. 10).

[0032] A counterfeit-protected data carrier, manufactured by the second method, comprises a transparent portion 11 on which part of the graphic elements 12 are formed by partial demetallization within the transparent material, and graphic elements 13 are applied to the carrier by printing.

[0033] Therefore, the inventive data carrier offers a novel optical variable effect. Information displayed on the surface of the transparent portion is hidden in reflected light and visible in transmitted light. This allows both the machine- readable authenticity control and visual inspection of the carrier, while greatly enhancing the effectiveness of visual inspection.

[0034] The advantage of the method of manufacturing a counterfeit-protected data carrier is that high-resolution graphic elements can be used, that are infeasible by digital printing devices and commercial printing; printing the elements does not require monitoring the accurate registration of the front and reverse sides, and the technological process is improved owing to the omission of additional steps, in particular, laser engraving, which reduces the cost of the counterfeit-protected data carrier. Application of graphic elements by traditional printing does not require extra processing steps and additional equipment.

Industrial Applicability

[0035] The invention can be used for protection against forgery of printed products, such as security papers, bank notes, identity documents, both paper and polymer-based; it ensures more efficient authenticity control of data carriers both visually and using an equipment.

Claims

1. A counterfeit-protected data carrier having at least one transparent portion with graphic elements disposed on both sides thereof in the form of a high-resolution line screen, said graphic elements forming a periodic structure, characterized in that the elements are mutually arranged such that they form an image which is hidden when viewed in reflected light and visible when viewed in transmitted light; furthermore, when viewed from a different direction in transmitted light the image changes from positive to negative and vice versa, and/or the color of the image changes completely or partially, and/or the effect of motion of monochrome or multi-colored moire fringes appears; the width of the graphical elements and the clearance between the graphical elements are proportionate to the thickness of the data carrier, and the thickness of the ink layer is in the range of from 3 to 9 µm, and the data carrier should retain its flatness after printing.

2. A data carrier according to claim 1, characterized in that the transparent portion of the data carrier can be formed by a single-layer or multilayer polymer film, transparent or partially colored in the bulk or on the surface, or partially demetalized; or a specially impregnated paper.

3. A data carrier according to any one of claim 1 or 2, characterized in that the image is formed by broken or curved lines, or dots, or strokes, or graphic primitives, or a combination thereof with the proviso of high resolution.

4. A data carrier according to any one of claim 1 or 2, characterized in that said graphic elements on the front and reverse side are computer readable at least at some portions.

5. A data carrier according to any one of claim 1 or 2, characterized in that said graphic elements on the front and reverse side are computer readable and/or luminescent under UV light and/or IR metameric (exhibit identical optical characteristics in the daylight and different absorption in IR light) at least at some portions.

6. A method for manufacturing a counterfeit-protected data carrier as defined in any one of claims 1 to 5, comprising applying graphic elements at least to both sides of a transparent portion of the carrier in the form of a line screen to form a periodic structure, characterized in that the graphic elements are formed by printing, wherein the data carrier retains its flatness after printing, and the elements are mutually arranged such that they form an image exhibiting an optically variable effect in transmitted light; the depth of engraving hatch should not exceed 14 µm and the thickness of the ink layer at the transparent portion of the data carrier should be within the range of from 3 to 10 µm.

7. A method according to claim 6, characterized in that the graphic elements on one side of the transparent layer are formed by partially removing of a pre-applied metalized layer by laser processing.

8. A method according to claim 6, characterized in that said applying of the graphic elements to the front or reverse side uses special inks that are computer readable and/or luminescent under UV light and/or IR metameric (exhibit identical optical characteristics in the daylight and different absorption in IR light).

Drawing