Security device

[0001] The invention relates to security elements for securing valuable items and documents such as banknotes, checks, identification documents such as passports, documents for securing trademarks and the like.

[0002] In the past, a wide range of security elements has been used, some of which are used directly on objects or documents, while others are in the form of labels that are applied to objects. Said security elements are in the form of printing and / or embossing and form a variety of different security patterns. When producing documents, they contain other security features, such as watermarks and galvanotypes.

[0003] US-A-6505779 describes the use of security signs formed by at least partially transparent windows made in a secure document, the presence of which can be detected in transmitted light. The characters are created within a security pattern that is designed to hide security characters when viewed in reflected light. This invention is based on the principle that it is possible to hide or hide small amounts of information in larger information structures that confuse the sight. The disadvantage of this technique is the use of a relatively large area of ​​the document and the lack of complete concealment of security characters.

[0004] US-A-6089614 describes another security element in which the first and second characters are located on opposite sides of the substrate, and the arrangement of the insert from the screening material is in accordance with the second characters, in order to eliminate the possibility of viewing at least the second signs on one side of the ground in reflected light. However, in transmitted light, the second characters can be viewed from one side of the ground.

[0005] There is a continuing need to provide new security features that are more difficult to reproduce by scammers and counterfeiters.

[0006] According to the present invention, the security element comprises one or more first areas printed or applied, wherein each of the first areas has one or more first colors, and one or more second areas printed or applied, characterized by the that one or more second or more printed or applied second areas are on the same side of the substrate as the first area / first areas, each of the second areas has one or more second colors, wherein at least one of the first and second areas contains a discontinuous pattern located on the background, and where the first area or first areas surround / surround the second area or second areas, each of the first areas may be distinguished from the second area or second areas; and in that the first area / first areas and / or the second area / second areas form the image; and the fact that the image and at least in the adjacent area surrounding the image has a masking pattern applied on the same side of the substrate as the first and second areas, while the masking pattern has such a chosen color and pattern that in combination with the first and second areas the pattern masking makes the image essentially invisible in reflected light, but is visible when viewed in transmitted light, wherein the elements forming the masking pattern and the areas of the substrate between the elements of the discontinuous pattern are approximately equal in size or the elements of the masking pattern have a line width similar to the width of the elements of the discontinuous pattern.

[0007] In most cases, the first area (s) creates / creates a negative image, which is the second area. This second area (s) contains / contain a discontinuous pattern. In some examples, however, the second area / second areas creates / form a positive area that is surrounded by a discontinuous pattern contained in the first area / first areas.

[0008] In this context, the discontinuous pattern comprises discrete elements printed or applied on the background. Background areas are defined as spaces between printed or applied elements.

[0009] It has surprisingly been found that a discontinuous pattern, which in other cases would be very pronounced in reflected light, can be hidden by printing a suitable masking pattern on it. The sense of sight disorientation occurs especially when the masking pattern contains lines of similar brightness as the background areas between the elements of the discontinuous pattern. In addition, the camouflage pattern should usually contain elements that have at least one dimension similar to the dimension of the background areas between the elements of the discontinuous pattern.

[0010] However, cases have also been found in which the line width of the elements contained in the masking pattern is much greater than the width of the background areas, but similar to the width of the discontinuous elements themselves, ie the masking pattern is of the "white-type" pattern.

[0011] In transmitted light, the masking pattern is no longer clearly visible in the first area / first areas and / or the second area / second areas forming the image, which is associated with the partial transparency of the masking print, due to which it ceases to perform the masking function, and the image becomes visible. In the case of examples with a negative image, if the sizes of the individual elements of the discontinuous pattern are small enough, the overall shape of the negative area is seen, not its individual elements.

[0012] Some of the advantages of the invention compared to the current state of the art are related to the fact that the invention can be manufactured in the form of a large element, which in transmitted light can be easily noticed by persons without special verification equipment, but in reflected light is largely hidden, it can also be economically and efficiently produced on a paper or polymer substrate having a suitable coating without the need for special equipment and / or materials. It enables the production of a printed element visible in transmitted light on documents printed using multi-aggregate printing presses. The element provides an increase in the level of security for documents containing other elements visible in transmitted light, because it encourages viewing documents in transmitted light, which also verifies other elements visible in transmitted light that are found in the document, e.g. watermarks, galvanotypes, embedded security threads , window threads, traditional transparent elements and the like. In a preferred embodiment, the structure of the security element is complemented by elements such as galvanotypes and transparent elements, for example in the form of an apple, which in visible light becomes visible both within the element and the galvanotype. The element is more difficult to counterfeit compared to the solutions known in the current state of the art, because it cannot be reproduced by methods of color copying or small DTP polygraphy, nor can it be easily disassembled into components in order to obtain the possibility of counterfeiting by photographic techniques or by separating lines and the use of printing techniques.

[0013] The discontinuous pattern forming one of the first and second regions preferably has approximately the same color (s) as the color / colors of the remaining of the first and second regions. However, some of the elements that make up the discontinuous pattern may have different colors. This is more important for lighter colors than for darker colors.

[0014] In all cases, the discontinuous pattern contained in the first area / first areas or second area / second areas should be brighter than in the remaining area / remaining areas, and when viewed in transmitted light the contrast between them increases, which makes the image visible. In reflected light, the contrast between the area containing the discontinuous pattern and the remaining area / remaining areas is masked by the masking pattern printed on top that has been described above.

[0015] Contrast is in this case defined as the difference between the brightness of two or more areas in the absence of any difference between their shades.

[0016] The discontinuous pattern usually comprises an arrangement of points, lines, squares or other small shapes, for example alphanumeric characters, graphic symbols and similar elements or combinations thereof, and usually occupies from 50% to 80%, preferably 60% to 70% of the first the second area in which it is located. The maximum size in the transverse direction of the individual elements forming the discontinuous pattern depends on its design, but is usually smaller than 1.5 mm, preferably smaller than 1 mm.

[0017] The discontinuous pattern may be a random, stochastic or regular pattern.

[0018] The elements forming the discontinuous pattern are preferably placed on a background that can be unprinted, may be previously printed with a matte shade or other discontinuous pattern that may not be matched with the main discontinuous pattern, or may be combined with it, or may be later printed with another matte shade or other discontinuous pattern that may not be matched with the main discontinuous pattern or may be matched with it. Preferably, the background areas are not printed.

[0019] The background areas are preferably white or have a light color, where if they are printed, this can be achieved by printing them at a low density. This allows you to vary the contrast between the color of the discontinuous pattern and the color of another area / other areas, so that the hidden image is clearly visible in transmitted light.

[0020] The first or second area, which does not contain a discontinuous pattern, preferably has a uniform color or colors, but can also be cut by thin unprinted lines or lines of another color, it can also be filled with dense halftones.

In all cases, if both the first and second areas are printed with a light shade on a white or light background, the discontinuous pattern is easier to mask by the masking pattern printed on it. However, the image is more difficult to see in transmitted light, because the contrast between the discontinuous pattern and the remaining area is insufficient.

[0022] The area may be applied / the areas may be applied using any conventional printing technique, e.g. gravure printing, lithographic printing, rotogravure printing, screen printing, flexographic printing, inkjet printing, laser printing, toner application or digital printing, or may be applied in the form of partially metallised foil, foil inserts with holographic print, a set of applied elements and the like. Areas preferably (but not necessary) are printed simultaneously. If a holographic foil or patch is used to create a discontinuous pattern, another area (s) may / may contain unmetallized foil.

[0023] The hidden image / hidden images can / can form simple shapes such as circles or squares or more complex shapes such as stars, alphanumeric characters or other images, for example representing a butterfly, apple or bird. The image is usually in the range of 10-15 mm x 10-15 mm, but its minimum transverse dimension can be from 2.5 mm to 30 mm or more.

[0024] Each first or second area may be single color, may contain two or more colors or rainbow colors. For printed areas, it is possible to use the full range of printing inks, including metallic, colored, optically variable, thermochromic, photochromic, luminescent and similar inks. In addition to the visible components, the ink may additionally contain components that can be machine detected, i.e. magnetic, luminescent, anti-Stokes components, detected in infrared radiation and the like.

[0025] The color or colors of the areas should be chosen so as to provide a relatively high contrast to the background areas between the elements of the discontinuous pattern. This ensures a relatively high contrast between the first and second areas. Measurements carried out on the examples showed that the brightness difference ΔL * between the discontinuous pattern and the adjacent area / adjacent areas should be from 5 to 30, more preferably from 10 to 20.

[0026] The image is visible in transmitted light due to the contrast between the discontinuous pattern and the other area (s).

[0027] It is possible to use the first image (s) to provide a characteristic, separate security element, or they may be included in a larger structure. The larger structure may contain other security elements that are commonly used in secured documents, e.g., copy protection structures, transparent elements, microtext and the like, as well as the other examples of the invention described herein.

[0028] The masking pattern is preferably selected in such a way that one dimension of the pattern, for example the thickness of the line forming the pattern consisting of lines, is approximately the same as the width of the background areas between the elements of the discontinuous pattern. For example, in the case of a black pattern consisting of lines, at least one dimension of the printed line should be approximately the same as the width of the background areas between the elements of the discontinuous pattern. However, in the case of a white pattern consisting of lines, at least one dimension of the unprinted area between the printed lines should be approximately the same width as the elements of the discontinuous pattern.

[0029] The color of the masking pattern is preferably chosen so that it matches the areas of the background visible through the discontinuous pattern, it may for example be white or have a light shade.

[0030] The masking pattern may be an integrated pattern or a separate individual pattern. The masking pattern may be regular or irregular and may consist of one or more lines, points, squares or other small shapes. Other preferred patterns are those that contain an additional expressive visual element, for example, the characters contained in the masking pattern.

[0031] The masking pattern may be printed using one of the following techniques: lithographic printing, rotogravure printing, screen printing, flexographic printing, inkjet printing, laser printing, toner application or digital printing or dye diffusion. In a preferred embodiment, white intaglio printing ink is used.

[0032] Preferred masking patterns comprise elements having a width in the range from 0.1 to 1.5 mm spaced apart by a distance from 0.1 to 4 mm, preferably elements with a width in the range from 0.25 up to 1.25 mm apart from 0.25 to 3 mm apart. It has been surprisingly found that even with a masking pattern with a high degree of ink coverage, a negative image may still be visible in transmitted light, provided that the applied ink is partially transparent. It is also preferred that the masking pattern itself contains characteristic images or patterns. The reason is the perception of the image viewed by the human eye, during which the brain tends to process images based on their grouping, which is why, for example, the discontinuous pattern underneath is not clearly seen.

[0033] A second, similar element may be located on the opposite side to the first element. Said second element may be printed in such a way that the discontinuous pattern is accurately aligned with the pattern of the first element, alternatively it is possible to print, also with an exact alignment, the pattern inverse to the discontinuous pattern. The print made with the exact composition can be viewed from the other side in the same way as a conventional transparent element, which makes it possible to conveniently check that the secured document has been printed using an ordinary printing press. The second image may be masked or not. In this case, it is possible to make a solution in which two "images" respectively form elements of a common, single image.

[0034] Generally, any print made on the other side that is not juxtaposed with a discontinuous pattern should be made in the region of the element with a low print density.

[0035] In all cases, the substrate should exhibit a sufficiently high translucency to allow the element to be viewed in transmitted light.

[0036] In all aspects of the invention, the security element may be placed in the area of ​​the substrate with a reduced degree of opacity compared to other parts of the substrate, although this is not a critical requirement. In the case of a paper substrate, said reduction in the degree of opacity can be achieved using a variety of techniques, such as those described in EP-A-0388090, GB-A-2282611 and GB-A-2283026, which aim to create a region with greater transparency during substrate production, or can be obtained during final treatment. This has the advantage that the element can be easily viewed in transmitted light without the use of specialized viewing equipment.

[0037] Instead of a paper substrate, it is also possible to use a polymer substrate.

[0038] The security element may be printed on a substrate such as paper previously coated with a security coating such as a Platinum® coating or subsequently coated with a security varnish.

[0039] The elements may be placed on valuable documents such as banknotes, identification documents and similar documents, or may be in the form of labels intended to be attached to objects or documents using a suitable adhesive.

[0040] Some examples of security elements according to the invention will be described below with reference to the attached drawing, in which:

Fig. 1 schematically shows a top view of a secured document provided with a security element;

Figures 2A, 2B and 2C show a negative image, enlarged view of a discontinuous pattern, and the masking pattern used in the first example of the security element, respectively;

Figures 3A to 3C are similar to Figures 2A to 2C, but relate to the second example;

Figures 4A to 4H illustrate further examples of security features against printing a masking pattern;

Figures 4I and 4J illustrate the appearance of the security element viewed in reflected and transmitted light, respectively;

Figures 5A to 5E illustrate further examples of discontinuous patterns; and Fig. 6 illustrates another example of a masking pattern.

[0041] Fig. 1 is a top view of a secure document 1 such as a banknote. Generally, printed information characteristic of this type of secured documents, e.g. denominations, money, portraits, consisting of lines of copy protection structures and the like, are in area 2. An example of a security element according to the present invention 3 is in area 2.

Example 1 (Figures 2A to 2C) [0042] Elements of this security element were printed on white paper with a basis weight of approximately 90 gsm and a degree of whiteness in the CIE L * a * b * model of 83, -1.5, 3 respectively 1. In this first example, the first area 5 of the single print was printed using the dark blue Pantone 294U lithographic printing technique with an L * value of 39, which creates a negative image 6 in the form of a star in the second area. Star 6 is filled with a discontinuous pattern 4 printed in roughly the same color as the uniform area 5. The discontinuous pattern 4 is formed in the form of a system of dots with a diameter of 0.6 mm, which are spaced apart to provide an overall density of ink coverage of approximately 70%. The louvre angle is 45 °. In Fig. 2B, the discontinuous pattern 4 is shown in enlargement. After measuring a discontinuous pattern 4 with the spectrophotometer and associated non-printed background areas, an L * value of approximately 52 was obtained. In the areas shown in Fig. 2A, the masking pattern 40 in Fig. 2C was printed using the intaglio and white printing method. The aforementioned masking pattern was designed in such a way that after printing it using white ink, when observing with the naked eye in reflected light, it is not possible to recognize the shape underneath the negative image 6. The degree of coverage of the masking pattern with printing ink is approximately 70%. The width of the line elements of the masking pattern is usually 0.250 mm. When observing in reflected light from a normal reading distance, image 6 is not perceived. When viewed in transmitted light, the shape of star 6 filled with discontinuous pattern 4 is clearly visible.

Example 2 [0043] This example was printed in the same way as example 1. The same discontinuous pattern 4 was used, but instead of the unprinted background areas between the points, the areas between the points were printed with a yellow Pantone 100U shade. After measuring a discontinuous pattern 4 with a spectrophotometer, the associated background areas L = a value of approximately 49 was obtained. The 2C masking pattern was printed using the intaglio printing method and roughly the same color as the Pantone 100U. In this example, when observing in reflected light from a normal reading distance, image 6 is not perceived. When viewed in transmitted light, the shape of star 6 filled with discontinuous pattern 4 is clearly visible.

Example 3 [0044] This example was printed in the same way as Example 1, but on paper with a blue shade of approximately 90 gsm and a whiteness degree in the CIE L * a * b * model of 80, -4.6, respectively , -4.4. The same discontinuous pattern 4 and masking pattern 2C were used. In this example, when observing in reflected light from a normal reading distance, image 6 is not perceived. When viewed in transmitted light, the shape of star 6 filled with discontinuous pattern 4 is clearly visible.

Example 4 (Figures 3A to 3C) [0045] The elements of this security element were printed on white paper with a basis weight of approximately 90 gsm. Fig. 3A shows the first areas of the uniform print 10A, 10B printed using the lithographic printing technique in purple Pantone 520U rainbow-colored 562U green and designating in the corresponding second areas two negative images 8, 9 forming the number "10". Each of the negative images 8, 9 is filled with a discontinuous pattern 7 having the same rainbow transition as the areas of uniform print 10A, 10B. The discontinuous pattern 7 is formed in the form of a 0.4 mm x 0.4 mm square pattern, which is surrounded by an unprinted rim providing an ink coverage density of approximately 60%. The louvre angle is 45 °. In Fig. 3B, the discontinuous pattern 7 is shown in enlargement. In the areas shown in fig. 3A, the masking pattern shown in Fig. 3C was printed using the intaglio printing method and white ink. The mentioned masking pattern, which consists of a number of repetitive characteristic elements of the pattern, has been designed in such a way that after printing it is impossible to recognize the shape of the images 8, 9 with the naked eye. The degree of coverage of the masking pattern with printing ink is approximately 70%. When observing in reflected light from the normal reading distance, images 8, 9 are not perceived. When observing in transmitted light, the shapes "1" and "0" 8, 9 filled with discontinuous pattern 7 are clearly visible.

[0046] In another example, the "1" and "0" shapes 8, 9 may be filled with discontinuous patterns 4 and 7, respectively, and in the alternative, the discontinuous patterns may contain repeating characters associated with shapes 8, 9, e.g. in the case of the shape of the number '1' and zeros in the case of the shape of the number '0'.

Examples 5 (Figures 4A to 4H) [0047] In the previous examples, the first areas 5 and 10a, 10B were in the form of simple shapes. It is possible to use more complex shapes. Figure 4 shows some examples. In Figs. 4A and 4B, as in Fig. 3A, the first area 10A penetrates into the surrounding printing area 11A, 11B, respectively. In Figs. 4C and 4D, the first area 10A is integrated with the larger pattern 12, 13. In Fig. 4E and 4F, the area of ​​the uniform print 14 and the discontinuous pattern 15 are inverted compared to the previous examples, and therefore, when viewed in transmitted light, the image formed, the number "5", is visible as a positive image, not as a negative image. In Fig. 4E, the first area has a uniform rim 16, whereas in Fig. 4E it does not. In Figs. 4G and 4H, the first region 17 having slight gaps creates a negative image 18 filled with a discontinuous pattern 19. In the case of Figs. 4G, said gaps are in the form of thin lines, while in Fig. 4H the gaps are unprinted areas in a halftone pattern with a high degree of coverage (> 80%). The first and second areas can be in the form of a single color, rainbow colors or multiple colors.

[0048] Figures 4A to 4H show a security element against printing a masking pattern.

[0049] Fig. 4I illustrates the appearance of a similar element to Fig. 3A, but the negative image is in the form of the number "5" and not the number "10". Fig. 4I illustrates this element viewed in reflected light, but it is obvious that the image is not visible because it is hidden by a "spiral" masking pattern printed using white intaglio ink. In fig. 4J shows this element viewed in transmitted light, with the picture "5" clearly visible here, because the masking pattern is no longer clearly visible.

[0050] In the above examples, discontinuous patterns 4, 7 and the like were created using points and squares. Other designs may also be used, provided that they provide a 50 to 80% coverage by ink. Some examples thereof are enlarged in Figs. 5A to 5E. These discontinuous patterns may have about the same color as other areas. However, some elements of the discontinuous pattern may have a different color or other colors, provided that these colors do not dominate the final result.

Example 6 (Fig. 6) [0051] A preferred way to add a distinctive visual element to the masking pattern in the form of patterns or characters that can be distinguished by sight is to include relatively large characters 20. An example of such a solution is shown in Fig. 6. when this pattern was printed in white by intaglio printing on an image such as that shown in fig. 2A and viewing it in reflected light from a normal reading distance, image 6 is not perceived. When viewed in transmitted light, the shape of star 6 filled with discontinuous pattern 4 is clearly visible. The reason that this masking pattern provides particularly effective concealment of the image 6 in reflected light is that it provides the visual sense with a clear image 20 on which it can be focused, so that this sense does not deal with distinguishing the image 6.

Example 7 [0052] In this example, the arrangement of the elements is the same as in Fig. 2. The elements of this security element were printed on white paper with a basis weight of approximately 90 gsm. However, in this example, the first area of ​​the uniform print 5 was printed using silver metallic ink with a gloss value of 60 gloss units, forming a negative image 6 in the form of a star. Star 6 is filled with a discontinuous pattern 4 printed in more or less the same color as the uniform area. The discontinuous pattern 4 is formed in the form of a system of dots with a diameter of 0.6 mm, which are spaced apart to ensure an overall density of ink coverage of approximately 70%. The louvre angle is 45 °. In Fig. 2B, the discontinuous pattern 4 is shown in enlargement. Due to the high gloss of metallic printing ink, when viewed in reflected light from a normal reading distance, image 6 is not perceived. When viewed in transmitted light, the shape of star 6 filled with discontinuous pattern 4 is clearly visible. No masking pattern is used in this example because the reflective properties of the ink ensure that the image is hidden.