MXPA01008402A - Improved security documents - Google Patents

Abstract

A security document, banknote, bond, travellers cheque, passport or token, including a substrate (1), said substrate having a device including a first macro-embossing (2, 3) of the substrate having a predetermined feature, and a second micro-embossing of smaller dimensions formed in or on said predetermined feature of said embossing. The first embossing being formed to hide and reveal said second embossing at predetermined viewing anglesa,ß. The macro-embossing may comprise lines having a height of about 20 microns and a spacing of 80 microns, and the micro-embossing in the form of lines or dots (4) to a height of about 2 to 5 microns. The lines have a predetermined height (H) and a predetermined spacing (S) such that the ratio S:H is typically from about 6:1 to 2:1. A transparent portion or clear window (W) of a polymer substrate (1) can be provided with embossing such that the first embossing is able to hide and reveal the finer second embossing at various viewing angles by using the gloss and transmission properties of the transparent substrate rather than the traditional reflection and absorption properties of the printed media.

Description

IMPROVED SECURITY DOCUMENTS Field of the Invention This invention relates to security documents or with distinguishing features, such as banknotes, traveler's checks, titles, passports and the like, and a method of producing same.

Background of the Invention The use of transparent windows in banknotes is now well known, as exemplified by patent PCT / AU82 / 00135 (WO 83/00659), "Banknotes" Enhanced and Similar "as well as its use as a carrier for security features One of these features is a transient image of the type described in patent PCT / AU94 / 00302 (WO 94/29229)," Enhanced Banknotes. "The transient nature of the image produced by the embossing depends on the properties of the transparent polymer film, which include excellent transparency / clarity at most viewing angles, and high-brightness characteristics or of reflection, when viewed perpendicular to a light source, as observed with a mirror.

Compendium of the Invention and Objects It is an object of the present invention to provide an improved security feature, which includes an additional level of complexity, which makes the security feature more difficult to reproduce or copy. The invention provides a security document or badge, which includes a substrate, this substrate has a security device that includes a first enhancement of the substrate having a predetermined characteristic, and a second enhancement of smaller dimensions, formed on the predetermined feature of the first enhanced, this first highlight is formed to hide and reveal the second highlight at predetermined viewing angles. In other words, the security device includes a macro-embossing of the substrate and a micro-embossing of a portion of the macro-embossing, this macro-embossing functions to hide and reveal the micro-embossing at predetermined viewing angles. Forming a second embossing, or micro-embossing, on the first embossing, or macro-embossing, this first embossing, or macro-embossing, hides and reveals the secondary embossing or micro-embossing at predetermined viewing angles, and, in this way , provides a security feature, which is then capable of being produced by high-level security procedures, at a reasonable price, while it is extremely difficult, for an average producer of security documents or a forger, to reproduce or simulate. The security feature is optically variable, however, it is easy for an ordinary person to use to identify a genuine document. The substrate is preferably a polymer substrate, such as a laminated polymer substrate, of the type used in the production of banknotes in Australia and in other countries. The first embossing is preferably formed on a transparent portion of the substrate, although acceptable results can be achieved by forming the embossed portion in other regions of the substrate. In a preferred form of the invention, the secondary embossing is preferably applied to the sides or bottom portions of the first embossing. By using the transparent portion of the polymer substrate, the first embossing is able to hide and reveal the second finer embossing at various viewing angles, using the brightness and transmission properties of the transparent substrate, rather than the traditional reflection and absorption of printed media.

In a simple embodiment, the macro-emboss may comprise an enhanced array of lines, formed on the substrate, these lines have a predetermined height, H, and a predetermined spacing, S. The height H may vary from a minimum of about 5 microns , to a maximum, which corresponds to the maximum height that can be enhanced from the substrate. The spacing S depends on the height and the S: H ratio is typically around 6: 1 to 2: 1. The micro-embossing can be formed as lines or points on the sides of the highlighted lines, so that secondary raised lines are hidden by the primary raised lines, in addition to a predetermined range of angles. Secondary lines or points are raised to a height of the order of approximately 2 to 20 microns, which causes the clear substrate to appear as a mat surface at the predetermined viewing angles. If desired, the lower portions of the macro-embossment, or portions of the substrate between the adjacent macro-embossments, may be micro-embossed, or in addition to the sides, or as an alternative thereto. In a preferred embodiment, the micro-embossing comprises lines having a height of about 5 to 3 μm, at a spacing of about 10 to 100 μm, and preferably a height of about 10 to 25 μm and a spacing of about 30 μm. up to 100 μm. The vertical lines created by the macro-enhancement are micro-enhanwith lines or points on their sides, in such a way that they cause a clear substrate to appear as a matte substrate, at viewing angles of approximately up to 45 ° to the substrate surface. . The micro-realization can be configured to form composite configurations, portraits, or any other recognizable device. The macro- and micro-embossing can be executed as part of the printing process and is particularly adapted to the engraving printing process. Tale processes are described more clearly in our earlier application WO 94/29119. The invention further provides a method for producing a security document or badge, which includes forming an enhansecurity device, having a predetermined feature on the substrate, and further a predetermined feature of enhancement, with a minor enhancement, so that the Enhansecurity device hide and reveal minor highlighting at predetermined viewing angles. The security device is preferably raised to a height of about 10 to 30 microns, and the sides of the embossing are, in turn, raised to a height of about 2 to 20 microns, the further embossing being plaso that the first Enhanhides and reveals secondary highlighting at predetermined viewing angles.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention is more easily understood, a preferred embodiment will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic elevation of part of an enhanced banknote, according to the invention; Figure 2 is a schematic representation of the banknote, when viewed at a predetermined angle, revealing the micro-embossing; Figure 3 is a view similar to Figure 2, in which a bank note is seen at an angle concealing the micro-emboss; Figure 4 is a schematic representation of a document, embodying the invention when viewed; Figure 4B illustrates several indices when viewed under different conditions; Figure 5 is a plan view of a printed document, such as a banknote, having the macro-embossed placed within a clear window in the document; Figures 6A to 6H schematically illustrate the process of making a macro-embossing engraving plate; Figures 7A to 7M schematically illustrate the manufacturing process of a micro-embossing engraving plate; and Figure 8 illustrates the calculation of the elongation ratio used in the formation of a micromask, to create a desired image in the micro-embossing.

DESCRIPTION OF THE PREFERRED EMBODIMENT Firstly referring to Figures 1 to 4, a simple embodiment of the invention is illustrated in Figure 1, which includes a substrate 1, such as a protective substrate used for the production of banknotes, and which it comprises a laminate of a polymer film, having a printed portion P and a portion L of a clear window, as illustrated in Figure 5, which has been macro-embossed with a series of parallel lines of embossing, 2, 3, having a height of about 20 μm and a spacing of 80 μm, each acro-enhanced line having a micro-embossed in the form of lines or points 4, at a height of about 2 to 5 μm, formed on its sides, so that micro-embossing 4 is visible when viewed at angles equal to or greater than a (14.5 °) and hidden when viewed at angles less than ß (7.2 °), as illustrated in Figures 1 and 2 and 1 and 3, respectively. In Figure 4A, a document substrate 1 is shown at a typical viewing angle of approximately 30 ° from normal and from this position the document can be flipped to the left or right, rotated up and down, or pivoted to the right or left, or any of its combinations. When viewed in this manner, the clear window W appears to be substantially transparent, as illustrated in (d) in Figure 4B. In the illustration of Figure 4B, the macro-enhanced lines comprise a set of vertical parallel lines and a set of horizontal parallel lines, in a generally triangular pattern, as illustrated in (a) of Figure 4B. When this pattern is maintained at right angles to the light source, the horizontal lines are substantially transparent, while the vertical lines are visible, as illustrated in (b) in Figure 4B. Conversely, when the horizontal lines are at right angles to the light source, these horizontal lines are visible and the vertical lines are substantially transparent, as illustrated in (c) of Figure 4B. Thus, the series of lines have three phases: 1. when a set of lines goes perpendicular to a light source, the image appears, because the lines reflect the light; 2. when a set of lines goes in the same direction as the light source, then this set of lines appears substantially transparent, and 3. when the light source is diffuse and the observer is looking through the clear area, the lines macro-enhanced are substantially invisible, as illustrated in (d) in Figure 4B. The micro-embossing 4 generates a secondary image, which causes the raised portions of the clear window W of the substrate 1 to appear matt when viewed at predetermined angles. Referring to Annex B, the image at the beginning becomes visible in the angle ß (7.2 °, in this case). In the angle a (24.5 °, in this case), all the micro-embossing is visible. The image will not be to scale at this point. The image will be optimal at this angle, in terms of continuity (low U / V ratio). However, the elongation angles have not been calculated in this angle. The angle of vision chosen for the calculation of the elongation angle is greater: 30 °. The image will be "recognizable" up to an angle of around 45 °. The reason that the image can not be seen at greater angles of this, is because the matte lines become thinner and the apparent spacing becomes wider, as illustrated in Annex B. The chosen angle of vision is selected by: Average (14.5, 45) = 30 °. The micro-embossing may be in the form of lines or dots of about 2 to 5 μm in height. When the micro lines / dots of this height are enhanced on the sides of the macro-embossed lines 2, 3, using an engraving printing machine, the lines maintain a particularly high fidelity, since the polymer of the substrate 1 has a weight high molecular Alternatively, similar results are achieved when the micro lines / dots are formed in the portions of the substrate 1, between the lines 2, 3, or instead of the lateral highlights, or in addition to them. The ratio of space to height, S: H, should be in the approximate range of 6: 1 to 2: 1. The height can vary from around 5 to 30 μm. which is close to the limit for the polymer substrate 1 of the preferred embodiment, although acceptable results in the height range of about 5 to 20 μm can be achieved. Within this range, the spacing between the S lines may vary between about 15 and 20 μm, for a height of 5 μm, between about 30 and 50 μm for a height of 10 μm, between about 30 and 90 μm for a height of 15 μm, between about 40 and 100 μm for a height of 20 μm, between about 50 and 100 μm for a height of 25 μm, between about 60 and 90 μm for a height of 30 μm, between about 65 and 75μm for a height of 35 μm. The table in Annex A illustrates the preferred parameters of height and spacing, with the shaded area representing the most preferred spacings for heights between 5 and 35 μm. See the attached Table. As illustrated in Figure 5, the macro-embossing comprises horizontal lines, while the micro-embossing is performed in a manner that includes a micro-mask reproducing a device, such as an arrow, having the appearance illustrated in the Figure 5, when the document flips down and up, respectively. Turning now to Figures 6 to 8 of the drawings, the macro-embossing process is illustrated in Figures 6A through 6H and comprises the following steps: 1. Rotate the photo-protective polymer on a copper metal plate in a thickness uniform up to 3 μm. 2. Place the macro-embossed mask on the photo-protective polymer. 3. Irradiate the surface with UV lamps. 4. Remove the UV lamps. 5. Remove the macro-enhanced mask. 6. Dissolve and wash separating the photo-protective polymer without exposing. 7. Use a solution of ferric chloride and copper, to engrave the macro-enhanced structure. 8. Remove the photo-protective polymer. If desired, the process can be carried out with a protective layer in the opposite light, using negative types instead of positive ones. Figures 7A to 7N illustrate the preferred process of micro-embossing, which involves the following steps: 1. Use the same plate, as that used for the macro-embossing, rotate the photo-protective polymer on the metal plate, ensure that the protective layer enters with a uniform thickness within the macro-enhanced structure, as shown in Figure 7A. 2. Place the revised macro-mask in the same position as the original macro-mask. This revised macro-mask will have the center of all macro-enhanced lines removed. 3. Irradiate the surface with UV lamps. This should be done to ensure that the non-engraved sections of the plate and the bottom section of the radar-embossed sections are exposed. 4. Remove the UV lamps. 5. Remove the revised macro-enhanced mask. 6. Place the first mask A micro-embossed on the protective layer in light. This mask A consists of an elongated image. This image is lengthened so that when viewed at the preferred optimum viewing angle of around 30 °, the image appears to scale. 7. Irradiate the surface with UV lamps. These UV lamps should be placed at an optimum viewing angle of around 30 ° to the horizontal. These lamps should radiate a uniform light in order to create correct exposure patterns, as shown in Figure 6. 8. Remove the UV lamps. 9. Remove the mask A. 10. Place the second micro-embossed mask B on the protective layer in the light. Mask B also consists of an elongated image, with an optimum viewing angle of 30 °. Mask B may consist of a different image than mask A. 11. Irradiate the surface with UV lamps. These UV lamps should be placed at the optimum viewing angle of around 30 ° to the horizontal, in the opposite direction to that of mask A. 12. Remove the UV lamps. 13. Remove the mask B. 14. Dissolve and wash and separate the protective layer in non-exposed light.

. Use hydrochloric acid to record the micro-enhanced structures. 16. Remove the polymer from the protective layer to light. In the previous process, both the micro-mask A and the micro-mask B consist of elongated images. The extent of elongation was previously determined by the preferred viewing angle. This preferred viewing angle has been set at approximately 30 ° for the document. Elongation ratio; x / y = 1 / sin (gamma) x = length of elongation of the image on the substrate. y = height of vision of the image. With an optimum viewing angle of 30 °, the extension extension is 2: 1. For example, if an image has a viewing height of 15 mm, then the image created by the micro-mask will be 30 m long on the substrate. The image is only elongated in the vertical viewing direction. Following the above processes, the engraving plate to achieve macro- and micro-embossing is obtained by the following steps: 1. A nickel metal plate grows from the copper plate. 2. The nickel plate is pressed into a PVC sheet. 3. The PVC slabs are cut and welded in the major engraving design. Directional enhancement images are usually a subset of a general engraving design. 4. The metal printing plate is made of welded PVC master slabs. 5. The engraving impression is executed as described in WO 94/29119. Some areas of the engraving plate can be inked like a traditional engraving print. The area of the engraving plate, which is intended for the directional enhancement feature, will not be inked. The embossing process is a continuous process, whereby the substrate to be enhanced is passed through two bearing cylinders under high pressure. The enhanced engraving plate covers one of the two cylinders, the other cylinder is the impression cylinder. During the process, the substrate is forced into the engravings of the plate by the printing cylinder. The substrate is plastically deformed in the configuration of the engravings. When the substrate leaves the rolling cylinders, the macro-embossing is partially reflected back into the configuration, due to the nature of the material. The embossing on the substrate remains intact. However, the height of the embossing is not equal to the engraving height on the plate, a typical ratio is around 1: 5. For this reason, the maximum expected final enhancement in the relaxed substrate is approximately 35 to 40 μm.

MAX U / V Viewing angle,? (degrees) 10 15 20 25 30 35 40 45 50 55 60 RELATION U V The horizontal interval is the acceptable range of vision for a ratio of S.H given U / V 2 RELATIONSHIP S: H to 1 45.00 22.50 2 26.57 13.28 14 4.09 2.04 15 3.81 1.91 Height (μm) 10 15 20 25 30 35 40 45 50 Spacing (μm) RELATIONSHIP S: H a ß 1 45.00 22.50 2 26.57 13.28 3 18.43 9.22 4 14.04 7.02 5 11.31 5.65 6 9.46 4.73 7 8.13 4.07 8 7.13 3.56 9 6.34 3.17 10 5.71 2.86 11 5.19 2.60 12 4.76 2.38 13 4.40 2.20 14 4.09 2.04 15 3.81 1.91

Claims (10)

1. CLAIMS 1. A security document or distinctive feature, which includes a substrate, this substrate has a security device, which includes a first embossing of the substrate, which has a predetermined characteristic, and a second embossing, of smaller dimensions, formed on said predetermined feature of the first embossing, this first embossing is formed to hide and reveal the second embossing at predetermined viewing angles.
2. 2. The document or distinguishing feature according to claim 1, wherein the substrate is a polymer substrate, such as a laminated polymer sheet, of the type used in the production of banknotes.
3. 3. The document or distinguishing feature, according to claim 1, wherein the first embossing is formed in a transparent portion of the substrate.
4. 4. The document or distinguishing feature, according to claims 1, 2 or 3, wherein the first embossing has side and bottom portions, the second embossing is formed in these side or bottom portions of the first embossing.
5. 5. The document or distinguishing feature, according to any of the preceding claims, in which the first embossing includes lines or points, having a height H and a spacing S, this height varies from about 5 microns to a maximum corresponding to the maximum height that it can be enhanced for the particular substrate, this spacing depends on the height, with the S: H ratio varying from approximately 6: 1 to 2: 1.
6. 6. The document or distinguishing feature, according to claim 5, in which the secondary embossing includes lines or points that are raised to a height of about 2 to 6 microns.
7. 7. The document or distinguishing feature, according to claims 5 or 6, in which the first enhancements have a height of about 5 to 30 microns, and a spacing of about 10 to 100 microns.
8. 8. The document or distinguishing feature according to claim 7, in which the height is from about 10 to 25 microns, and the spacing is from about 30 to 100 microns, the second enhancement is such that the substrate appears as a matte substrate at angles of vision between approximately 5 and 45 °.
9. 9. A method for producing a security document or distinguishing feature, which includes forming an enhanced security device, having a predetermined feature on the substrate, and then enhancing the predetermined feature with minor enhancement, so that this enhanced security device hides and reveal the minor highlight, at predetermined viewing angles.
10. 10. The method of claim 9, wherein the document or distinguishing feature is enhanced in the manner claimed in any of claims 3 to 8.