Security document installed with security device demonstrating improved harvesting resistance

Abstract

To improve anti-harvesting property of a security device (SD).SOLUTION: A security document (10) comprises: a security substrate (16); a security device (14); and a structural weakness element (12). The security device is coupled to the security substrate. The structural weakness element is integrated with at least one of the security substrate or the security device. The structural weakness element defines an anti-harvesting area (17) and a bulk area (19). The anti-harvesting area has one or more of structural fidelity or optical fidelity with the bulk area.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] SUMMARY The present disclosure relates generally to a security document having a security device coupled to a security substrate and having a structurally fragile element incorporated therein. [Background technology]

[0002] Security documents may be made less susceptible to tampering or counterfeiting by incorporating security devices. Security devices have a variety of security features and are provided in a variety of forms within a security document. The security or integrity of a document or paper generally increases, all other things being equal, with the complexity and number of separate and distinct security features contained within the document or paper.

[0003] Counterfeiters often rely on the knowledge of contemporary printing and copying technologies to copy genuine security documents. In recent years, anti-counterfeiting security devices, specifically security threads and patches with optically variable security features, have been increasingly used as authentication features to secure security documents. Optically variable security features appear visually different to viewers from different viewing angles. Therefore, even the most developed printing and copying technologies are unable to mimic the optical variability provided by the optically variable features.

[0004] By way of example, U.S. Patent No. 7,333,268 to Steenblik et al. describes a micro-optical film material that generally includes (a) an arrangement of micro-sized image icons disposed on or in a polymer substrate, and (b) an arrangement of focusing elements (e.g., microlenses). The arrangement of image icons and focusing elements is configured such that when the arrangement of image icons is viewed through the arrangement of focusing elements, one or more composite images are projected. These composite images may exhibit optical variability by exhibiting a number of different optical effects (e.g., changes in color, size, shape, number, etc.) when viewed from various viewpoints. Material configurations capable of providing such effects are also described in U.S. Pat. No. 7,468,842 to Steenblik et al., U.S. Pat. No. 7,738,175 to Steenblik et al., U.S. Pat. No. 7,830,627 to Commander et al., U.S. Pat. No. 8,149,511 to Kaule et al., U.S. Pat. No. 8,878,844 to Kaule et al., U.S. Pat. No. 8,786,521 to Kaule et al., European Patent No. 2 162 294 to Kaule et al., and European Patent No. 2 164 713 to Kaule.

[0005] International Patent Application No. PCT / GB2005 / 001618 to Commander et al. describes a security device comprising a substrate having an array of microlenses on one side and one or more corresponding arrays of microimages on the other side. The distance between the microlens array and the microimage array(s) is substantially equal to the focal length of the microlenses. The substrate is sufficiently transparent to allow light to pass through the microlenses to reach the microimages. Each microimage is defined by an anti-reflective structure (e.g., a moth-eye structure) on the substrate. The anti-reflective structure is formed by a periodic array of identical structural elements and an at least partially reflective layer. The microimage is formed by one or both of the anti-reflective structure and the at least partially reflective layer. Light passing through the substrate and impinging on the microimage is reflected to a different extent than light not impinging on the microimage, thereby making the microimage visible.

[0006] For banknotes and other security documents, these security threads and patches are either partially embedded within the banknote or document or affixed to its surface. For passports or other identification (ID) documents, these materials may be used as fully laminated.

[0007] Due in part to the general effectiveness of security devices, such as those described above, in preventing counterfeiting based on copying the security device, counterfeiters have had to turn to a number of other techniques to create counterfeit security documents. One such technique is harvesting. The term "harvesting," in the context of this disclosure, encompasses removing or decoupling a security device intact from the security substrate of a security document for the purposes of either counterfeiting, imitation, or substitution. Harvesting is a method of counterfeiting when traditional counterfeiting (e.g., photocopying, or other methods of reproduction) is technically impossible or otherwise not an option. Summary of the Invention

[0008] Surprisingly, the inventors of the present disclosure have found that improved anti-harvesting properties of a security device (SD) can be achieved by incorporating a structurally vulnerable element (SWE) into a security document such that the security device comprises an anti-harvesting area and a bulk area. According to some embodiments, the anti-harvesting area produces a structural or visual change in the security device when an attempt is made to harvest the security device from the security document. In some embodiments, the anti-harvesting area prevents all or a portion of the security device from being removed intact from the security document. According to certain embodiments, the structurally vulnerable element is incorporated as part of the security document in such a way that the anti-harvesting area exhibits structural or optical fidelity with the bulk area of ​​the security document.

[0009] Embodiments of the present disclosure include (i) a security document; (ii) a method of forming the security document; (iii) a product-by-process, the product being a security document formed by a process defined by the method of aspect (ii); and (iv) the use of a structurally fragile element.

[0010] In a first embodiment, a security document comprises a security device (SD) coupled to a security substrate, and a structurally fragile element (SWE) is incorporated into the security substrate, the security device, or both to define an anti-harvesting area and a bulk area within the security device. The anti-harvesting area has at least one of structural or optical fidelity with the bulk area. The security device, and by extension the security document having the security device incorporated therein, is provided with improved harvesting resistance compared to conventional security documents (e.g., a bank note having a micro-optical security device as described in U.S. Patent No. 7,333,268 to Steenblik et al., but at least without the structurally fragile element).

[0011] In a second embodiment, a method of forming a security document includes providing a security document having an attached (e.g., bonded) security device and incorporating a structurally fragile element into the security device or security substrate, the structurally fragile element being configured to cause the security device or security document to fail when an attempt is made to separate the security device from the security substrate.

[0012] In a third embodiment, a security document comprises a security device (SD) coupled to a security substrate, and a structurally fragile element (SWE) incorporated into the security substrate, the security device, or both to define an anti-harvesting area and a bulk area within the security device. The security document is formed by providing a security document having an affixed (e.g., coupled) security device and incorporating the structurally fragile element into the security device or the security substrate.

[0013] In a fourth embodiment, the use of a structurally fragile element to provide enhanced anti-harvesting resistance includes providing a security document as described herein, where the security document includes a security substrate coupled to a security device, and a structurally fragile element incorporated into the security substrate or security device to define an anti-harvesting area and a bulk area such that the anti-harvesting area has at least one of structural fidelity or optical fidelity with the bulk area.

[0014] The presently disclosed embodiments are directed to providing an apparatus and method for discouraging harvesting of a security device. More importantly, the presently disclosed embodiments are directed to providing a security document that exhibits improved harvesting resistance without affecting the counterfeit resistance provided by the security device incorporated therein. For example, it has been surprisingly found that incorporating a structurally fragile element as part of the security document provides improved harvesting resistance, and in some embodiments, improved harvesting resistance without affecting the counterfeit resistance provided by optically variable features found in certain threads, patches, and the like. Surprisingly, certain embodiments that incorporate a structurally fragile element after the security device is securely bonded to the security substrate provide at least one of optical fidelity and structural fidelity between the anti-harvesting area and the bulk area of ​​the security device. As used herein, the term "optical fidelity" encompasses security devices that provide an optically variable image in the anti-harvesting area that is at least substantially similar to an optically variable image found in the bulk area. This may be particularly advantageous in the context of composite image(s) provided by a micro-optical security device (e.g., a thread), such as that provided in U.S. Patent No. 7,333,268 to Steenblik et al. According to various embodiments, certain micro-optical security devices (such as stripes or patches) are particularly suited for combination with the structurally fragile elements disclosed herein because such security devices include an array of focusing elements through which the structurally fragile elements can be formed to complement the composite image without destroying the underlying image icon (i.e., image element). As used herein, the term "structural fidelity" encompasses the property that the security thread in the anti-harvest area is not deformed relative to the shape of the thread in the bulk area.Alternatively, when structurally fragile elements are incorporated in the anti-harvesting area, they do not deform in any significant way. Applicant has surprisingly found that this may be advantageous in the context of products utilizing security devices (e.g., threads, stripes, patches, etc.), such as those provided in U.S. Patent No. 7,333,268 to Steenblik et al. Such security devices, being constructed of polymeric base materials, may be susceptible to physical deformation in the anti-harvesting area due to the variability of the stretch or tension applied to the security device during bonding to the security substrate. For example, adjusting the tension will stretch the security device and also cause a permanent or apparent deformation of the anti-harvesting area separate from the bulk area. For example, stretching the substrate may cause the width of the thread to narrow faster in the anti-harvesting area. Alternatively, stretching the substrate may cause the structurally fragile elements to deform the optically variable effect faster in the area around the security device than in the bulk area. Thus, depending on how the security device is integrated into the bulk area of ​​the substrate, tensile stresses on the substrate may destroy the structural integrity between the two areas, for example by causing a tapering of the anti-harvesting area that is not replicated in the bulk area. However, by first bonding the security device to the security substrate as described with reference to certain embodiments of the present disclosure, the security device can be retained in the security substrate, such that the structurally fragile elements do not affect the structural integrity of the security device during the bonding phase. This is because the security device will already be bonded to the security substrate. Thus, the structurally fragile elements will not cause the security device in the anti-harvesting area to lose the structural or optical fidelity that matches the bulk area. Rather, the security document with the security device bonded to the security substrate is not tapered or otherwise deformed.

[0015] In certain embodiments of the present disclosure, the structurally fragile element comprises a set of perforations formed in the security device, the security substrate, another component layer of the security document, or any combination thereof. As used herein, the term "set" encompasses one or more items of a particular type. In certain embodiments, the set of perforations is arranged to define an anti-harvesting area separate from the bulk area of ​​the security device. In embodiments with multiple perforations, the perforations may be arranged randomly or in a pattern and may define bulk and anti-harvesting areas.

[0016] In certain embodiments according to the present disclosure, the security document is a bank note comprising a security substrate, a security device, and a structurally fragile element, which in some embodiments is a thread (i.e., a patch or stripe) coupled to (i.e., surface-fixed, embedded, or partially embedded in) the security substrate, and the structurally fragile element is a set of perforations incorporated into at least one of the security substrate and the security device to define anti-harvest and bulk areas within the security device that have structural and optical fidelity to one another.

[0017] Further advantages and embodiments of the present disclosure will be readily apparent to those skilled in the art (PHOSITA) in view of the following detailed description. As will be apparent, the non-limiting examples described herein can be modified, and such modified embodiments are within the scope of the present disclosure. The present disclosure may be practiced without some or all of these specific details. In other instances, the operation of well-known processes has not been described in detail to avoid unnecessarily obscuring the present disclosure. Thus, the drawings and detailed description are to be regarded as illustrative in nature, and not restrictive.

[0018] Other technical features may be readily apparent to those skilled in the art from the following drawings, detailed description, and claims.

[0019] Before embarking on the detailed description below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "coupled" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not they are in physical contact with one another. The terms "include" and "comprise" and their derivatives mean inclusion, without limitation. The term "or" means inclusive and / or. The phrase "associated" and its derivatives mean including, contained therein, interconnected, containing, contained therein, connected, coupled, capable of communicating, cooperating, interleaved, juxtaposed, adjacent, bound, having, having the nature of, having a relationship, and the like. The phrase "at least one," when used in conjunction with a list of items, means that various combinations of one or more of the listed items may be used, and also that only one item in the list may be required. For example, "at least one of A, B, and C" includes any of the combinations of A, B, C, A and B, A and C, B and C, and A, B, and C.

[0020] Definitions for other specific words and phrases are provided throughout this patent document, and those of skill in the art will understand that in most, if not all, instances such definitions apply to prior and future uses of such defined words and phrases.

[0021] For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals refer to like parts and in which: [Brief description of the drawings]

[0022] [Figure 1A]FIG. 1 illustrates an example of a security document in accordance with some embodiments of the present disclosure, in which a set of perforations extend at a perpendicular angle through the entire thickness of both the micro-optical security device and the underlying security document. [Figure 1B] FIG. 2 illustrates an example of a security document according to some embodiments of the present disclosure, where a set of perforations extend at an oblique angle instead of a perpendicular angle. [Diagram 2] FIG. 1 illustrates an example of a security document according to some embodiments of the present disclosure, in which a set of punch holes serve to cut out two focusing elements, but not the underlying optical spacer and image icon. [Figure 3A] FIG. 1 illustrates an example of a security document in accordance with some embodiments of the present disclosure, where a set of perforations extend at a perpendicular angle through the entire thickness of only the micro-optical security device. [Figure 3B] FIG. 2 illustrates an example of a security document according to some embodiments of the present disclosure, where a set of perforations extend at an oblique angle instead of a perpendicular angle. [Figure 4A] FIG. 2 illustrates an example of a security document according to some embodiments of the present disclosure, where a set of perforations extend at a perpendicular angle through the entire thickness of only the underlying security document. [Figure 4B] FIG. 2 illustrates an example of a security document according to some embodiments of the present disclosure, where a set of perforations extend at an oblique angle instead of a perpendicular angle. [Diagram 5] FIG. 1 illustrates an example of a security document in accordance with some embodiments of the present disclosure, where perforations have been applied in a pattern, with a set of perforations applied as (a) a matrix of dots forming a dollar sign symbol contained within the boundary of the security thread, and (b) non-linear lines spanning the security thread and extending outward into the body of the security document. [Figure 6]FIG. 1 illustrates an example of a security document in accordance with some embodiments of the present disclosure, where trapezoidal and linear perforations are used to cut the security device into what appears to be a patch. [Figure 7] FIG. 1 illustrates an example of a security document according to some embodiments of the present disclosure, the security document being a bank note, where a set of punch holes are used to serialize the bank note, spanning the security device and extending into the body of the bank note to serialize the number. [Figure 8] FIG. 1 illustrates an example of a security document according to some embodiments of the present disclosure, in which linear perforations are formed in the security device, some of which extend toward and interrupt the edge of the attached device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Certain embodiments of the present disclosure relate to security documents that provide improved harvesting resistance without any attendant degradation of the counterfeit resistance provided by the security device. In some embodiments, the security document comprises a structurally fragile element incorporated within at least one other component of the security document, such that the security device or security substrate of the security document is defective upon an attempt to harvest the security device. Surprisingly and advantageously, in certain embodiments, the structurally fragile element can be incorporated after the security device is bonded to the security substrate without causing damage to the security device or the security substrate. Although it is expected that the structurally fragile element can be applied to the security device before the structurally fragile element is applied to the security substrate, the applicant has found that under such conditions the security device may become deformed upon bonding to the security substrate. Such deformation may disrupt the structural or optical fidelity between the harvesting-resistant area of ​​the security device and the bulk area of ​​the security device. In various embodiments of the present disclosure, the security device is first bonded to the security substrate, and then the structurally fragile element is incorporated into at least one of the security device and the security substrate. Thus, in some embodiments, the resulting security document includes a security device having at least one of structural fidelity between the anti-harvesting area and the bulk area, or optical fidelity between the anti-harvesting area and the bulk area.

[0024] As previously described herein, embodiments of the present disclosure include (i) a security document, (ii) a method of forming the security document, (iii) a product-by-process, where the product is a security document formed by a process defined by the method of (ii), and (iv) the use of structurally fragile elements, and more broadly, the use of the security documents of (i) and (iii) to impart anti-harvesting properties to the security document.

[0025] Security Board A variety of suitable security substrates will be apparent to those skilled in the art in view of the present disclosure. These embodiments are understood to form alternative embodiments to those described herein and are therefore within the scope of the present disclosure. For example, substrates that include paper or other fibrous materials, such as cellulose, paper-containing materials, composite materials, paper-polymer hybrids, and combinations thereof, are contemplated to be within the scope of the present disclosure. Examples of composite materials include, but are not limited to, multi-layered structures or laminates of paper and at least one plastic or polymeric material. In some embodiments, the security substrate is a fibrous paper substrate.

[0026] Security Devices Security documents according to certain embodiments of the present disclosure include a security device coupled to a security substrate. In view of the insights of the present disclosure, various embodiments of the present disclosure including a variety of suitable security devices will be apparent to those skilled in the art. Thus, the specific security devices described herein are merely exemplary. For example, although a micro-optical security device is described herein, other security devices are contemplated within the scope of the present disclosure, including security devices with and without optically variable features.

[0027] Examples of security devices suitable for use in certain embodiments of the present disclosure are described, without limitation, in U.S. Patent No. 9,873,281 to Cape et al. These single layer systems are formed of an arrangement of optionally reflective arcuate elements having an upper arcuate surface, a lower surface, an arcuate area bounded by the upper and lower surfaces, and an optionally reflective pattern of image relief microstructure disposed on or within at least some of the optionally reflective arcuate elements. The arrangement of optionally reflective arcuate elements and the optionally reflective pattern of image relief microstructure are within a single layer and interact to project one or more images.

[0028] The microstructures in a particular single layer security device may extend from the upper arcuate surface to the lower surface, or may alternatively begin or terminate at a point between the surfaces. For a category of microstructures beginning or terminating at a point between the surfaces, for an upper arcuate surface having a convex surface curvature, the microstructure of the image relief extends downward from the surface and terminates in an arcuate area. For an upper arcuate surface having a concave surface curvature, the microstructure of the image relief extends upward from the surface and terminates within an area defined by the curvature of the upper arcuate surface. One or more images are formed by transmission of light through the system, reflection of light from the system, or a combination thereof.

[0029] Examples of multi-layer security devices that can be used in embodiments of the present disclosure include, but are not limited to, published international patent applications WO2005 / 052650, WO2006 / 125224, WO2008 / 008635, WO2011 / 019912, WO2011 / 163298, WO / 2013 / 028534, WO No. 6,399,992, WO2014 / 143980, WO2009 / 017824, WO2016 / 044372, WO2016 / 011249, WO2013 / 163287, WO2007 / 133613, WO2012 / 103441, WO2015 / 148878, WO2005 / 106601, and WO2006 / 087138, all of which are hereby incorporated in their entirety herein. Such security devices may include one or more arrangements of image elements (i.e., image icons) on or within a surface of a substrate, and one or more arrangements of focusing elements (e.g., microlenses). The focusing elements are disposed substantially parallel to the arrangement(s) of image elements and at a distance from the image elements sufficient for the microlenses to project one or more synthetically magnified images of the image elements in the image icons. Groups of associated focusing elements (e.g., microlenses) and image elements (e.g., icon structures) may or may not be repeated across the length or width of the image security device and may or may not collectively form, magnify, and project a composite image (i.e., optically variable feature). As an example, the microlenses / icon structures project one or more synthetically magnified images as the system is tilted or the viewing angle changes.

[0030] In some embodiments, the micro-optical security devices described herein include a device substrate that is optically transparent. In one embodiment, such a device substrate is an optically transparent polymer film. In such a micro-optical security device, the optically transparent polymer film functions as an optical spacer. The optically transparent polymer film of certain embodiments may be formed of one or more essentially colorless polymers, such as polyester, polyethylene, polyethylene terephthalate, polypropylene, polyvinyl carbonate, polyvinylidene chloride, and combinations thereof.

[0031] According to various embodiments, the thickness of the light-transmitting polymer film ranges from about 12 microns to about 26 microns (in some embodiments, from about 13 microns to about 17 microns). Suitable focusing elements include, but are not limited to, microlenses, such as (i) one or more arrangements of cylindrical or non-cylindrical lenses, (ii) one or more arrangements of focusing reflectors, (iii) one or more opaque layers containing multiple apertures, and (iv) one or more reflective layers.

[0032] The focusing elements according to various embodiments of the present disclosure can be non-cylindrical lenses, in particular lenses having spherical or aspherical surfaces. Aspherical surfaces include conical, elliptical, parabolic, and other profiles. The lenses may have circular, ovoid, or polygonal base geometries and may be arranged in regular or random one- or two-dimensional arrays. In a particular embodiment, the microlenses are aspheric lenses having polygonal (e.g., hexagonal) base geometries arranged in regular two-dimensional arrays on a substrate or light-transmitting polymer film.

[0033] Microlens focusing elements according to various embodiments of the present disclosure have widths and base diameters less than about 50 microns. In certain embodiments, widths less than about 45 microns or between about 10 microns and about 45 microns may be advantageous. In various embodiments, the focal length for these focusing elements is less than about 50 microns, with focal lengths less than about 45 microns or between about 10 microns and about 30 microns being particularly advantageous in some embodiments. Focusing elements according to certain embodiments of the present disclosure have f-numbers of 2 or less, with f-numbers of 1 or less being advantageous in certain embodiments.

[0034] Image elements (i.e., icons) according to various embodiments of the present disclosure include one or more icon designs. Additionally, an image element may include one or more slices (i.e., narrow bands or strips) from one or more image element designs, with each slice being spaced slightly apart from, abutting (i.e., touching or joining at an edge or border) adjacent slice(s), or slightly overlapping adjacent slice(s). The slices may be manipulated with respect to content, spacing, or degree of overlap to adjust or better tune the final projected image(s).

[0035] The icon designs used to prepare the first type of image icon (i.e., a complete image icon formed of one or more icon designs), or the second type (i.e., a so-called stitched icon), may be any type of fixed or fluid graphic design, including, but not limited to, positive or negative symbols, shapes, letters, numbers, text, and combinations thereof. Examples of fixed icon designs include stars, boxes, bells, bells combined with numbers, etc., while examples of fluid icon designs include blinking eyes and contracting or rotating currency symbols.

[0036] To form a stitched icon, the icon designs that will form the stitched icon are broken down into bands or strips. The bands or strips from each icon design may then be arranged in a staggered or interleaved fashion with the slices spaced apart, abutting, or slightly overlapping to form the stitched icon. Each slice in the stitched icon is aligned behind one or more lenses at the focal point(s) of the lens. In certain embodiments of the present disclosure, a computer program is used to prepare the slices. U.S. Patent No. 8,739,711 to Cote provides a non-limiting selection of examples of stitched icons suitable for use in embodiments of the present disclosure.

[0037] While certain embodiments of the present disclosure are described primarily in the context of security devices having optically variable features, it is to be understood that the scope of the present disclosure is not so limited. It is also to be understood as being applicable where the security device does not include an optically variable feature or uses a combination of static and optically variable features. Furthermore, the security devices may take a variety of forms, such as single or multi-layer film materials employing metal, fluorescent and magnetic elements with metal coatings and selectively demetalized, color shifting, holographic, 3D effects, gratings, and combinations thereof.

[0038] join Certain embodiments according to the present disclosure include a security document with a security device coupled to a security substrate. It should be understood herein that in some embodiments, the security device is directly coupled to the security substrate, however, it is also contemplated herein that the security device may be indirectly coupled to the security substrate. Thus, references to coupling the security device to the security substrate shall be understood and read in this context. For example, in one embodiment, the security device is directly bonded to the surface of the security substrate by adhesive. In alternative embodiments, the security device is bonded to interleaved components such as a constraining layer, a masking layer, a reflective layer, an ink layer, or other machine detectable (e.g., IR, fluorescent, etc.) material layer. These components are then bonded directly or indirectly to the security substrate. Furthermore, the bonding of the security device to the security substrate, whether directly or indirectly, may be at the top or bottom surface of the security substrate or embedded therein. It is also contemplated herein that in some embodiments the security device may be in the form of a strip or patch. In the case where the security device is a strip / strip, it is contemplated that the strip may be affixed to the surface, embedded, or woven into the paper. When a security device is surface affixed, the entire surface of the security device is exposed, while for a woven security device, a portion of one surface of the security device is hidden under a portion of the security substrate. For example, a woven security device forms a window within which the security device is accessible / visible and forms a bridge, below which the security device is inaccessible / hidden. When the security device is embedded, it can be embedded underneath, within the security substrate, and in one embodiment is visually detectable through transmitted light.

[0039] Further methods for directly or indirectly bonding the security device, such as those that may be apparent to one skilled in the art, are within the anticipated scope of the present disclosure. For example, heat, water, or radiation activated adhesives are most suitable. Alternatively, the security device may be bonded directly to the security substrate during or after its formation. For example, in one exemplary embodiment, the security device is bonded to the security substrate by weaving it into the fiber slurry used to form the security substrate, and is also woven with the slurry during the paper manufacturing process. In some embodiments, it is further anticipated that a pressure, heat, water, or other radiation activated adhesive is affixed between the security device and the security substrate to bond the two components of the security document. In some embodiments, it may be advantageous to use a heat or water activated adhesive.

[0040] As described herein, in certain embodiments, the security device may be a thread (i.e., a patch or stripe). Bonding a security device to a security substrate during the manufacturing process of the security substrate often requires in-process adjustment of the tension on the security device during manufacturing. As part of such in-process adjustment, the security device is stretched, compressed, or released. Such in-process adjustment causes the security device to be deformed by generating at least one of an optical defect or a structural defect. Here, the anti-harvesting area of ​​the security device may lose at least one of its optical or structural fidelity with the bulk area of ​​the security device. The present disclosure is most suitable when the security device is a stripe. This is because the greatest stretching (change in tension) of the security device occurs when bonding the security device to the security substrate.

[0041] According to various embodiments, when a single or multiple layer micro-optical security device is provided as a security thread, it may be woven (i.e. partially embedded) into the banknote and is visible only in clearly defined windows and hidden in certain sections of the banknote's surface. These windows, in certain embodiments, measure from about 6 millimeters (mm) to about 21 mm in length and about 3.5 mm to about 4.5 mm in width, while allowing for a range of imaging groups from about ½ to about 5 in number to be physically present in any such window. The security device may be designed such that the imaging groups in each window project images having the same or different optical effects. To further improve the counterfeit resistance of the banknote, the security device may be bonded to a security substrate, such that these projected images may be coordinated with images printed on the security device or security substrate.

[0042] According to various embodiments, when the single or multi-layer micro-optical security device is in the form of a patch, the security device may be affixed to the surface of the banknote by an adhesive. In one contemplated embodiment, an adhesive layer having a thickness ranging from about 3 microns to about 12 microns is affixed to the surface of the patch. Suitable adhesives are not limited, and include thermoplastic adhesive systems, including acrylics (e.g., poly(methyl methacrylate)), and polyurethanes, as well as heat-activated adhesives (i.e., hot melt or heat seal adhesives).

[0043] Structural weak elements As discussed elsewhere in this disclosure, harvesting is a practical mechanism for creating counterfeit or inauthentic security documents, and thus preventing harvesting remains a source of technical challenge and motivation for improving security device and security document performance. It is further desirable to be able to incorporate anti-harvesting features into security documents without compromising or eliminating the anti-counterfeiting features of the security device. It is also desirable to be able to incorporate anti-harvesting features into security documents without affecting the binding of the security device to the security substrate of the security document. It is therefore an objective of embodiments of the present disclosure to provide security devices that appeal to users' concerns regarding harvesting resistance. The term "structural weakness" as used in this disclosure encompasses portions of a security device or security document that contain an applied defect that causes a structural or optical defect in the security device, rendering the device inoperable (e.g., by ceasing to provide an optical variability that provides an indicia of authenticity) in response to an attempt to harvest the security device from the security document.

[0044] In certain embodiments of the present disclosure, by forming a point of weakness (an anti-harvesting area) in the security device or security substrate, the harvesting resistance of the security device / security document is increased without negatively impacting the counterfeiting resistance of the security device / security document. The structurally fragile element provides the security document or security device with increased harvesting resistance. In certain embodiments, the structurally fragile element causes the device or document to fail (i.e., break, crack, deform, or separate) when an attempt is made to separate (e.g., forcibly remove) the security device from the security document. In selected embodiments, the structurally fragile element prevents the security device from being separated (i.e., decoupling) from the security substrate without permanently or visibly deforming or damaging the security device, security substrate, or security document. For example, in certain embodiments, the structurally fragile element prevents the security device from being decoupled as a single, reusable piece, thereby preventing its harvesting and reuse on counterfeit security documents. In certain embodiments, the present disclosure is suitable for securing and authenticating security documents such as identification documents (e.g., passports, government IDs, etc.), monetary documents (e.g., checks, bank notes, etc.), or consumer product documents (e.g., labels, signs, tags, etc.).

[0045] In certain embodiments according to the present disclosure, the optical variability of the security device remains, for example, intact and functional, even when a structurally fragile element is added to the device, thereby maintaining its ability to thwart counterfeiting attempts that rely, for example, on improved printing / copying techniques. However, because the structurally fragile element, in some embodiments, is strategically incorporated into at least one structural element of the security document, an attempt to harvest the security device will identifiably deform the security device. Such identifiably deformed compromises the security device, making it unsuitable for use with a counterfeit document, where the security device of the counterfeit document will have a visual indicia of authenticity provided by the security device. These identifiably deformed may be more easily understood as structural or optical defects of the security device. As used herein, the term "structural defects" encompasses at least a portion of the security device being torn, shredded, broken, crumpled, or split. This prevents the security device from being transferred intact from a genuine document to a counterfeit document. As used herein, the term "optical defect" encompasses the visual degradation of an optically variable feature of a security device. Examples of optical defects include, but are not limited to, rendering a dynamic (e.g., moving) optically variable feature static, rendering an optically variable feature invisible, or reducing the quality (e.g., transparency) of an optically variable feature.

[0046] According to certain embodiments of the present disclosure, it is contemplated herein that the structurally fragile element may be incorporated into any layer or component of the security document. In certain embodiments, it may be advantageous to incorporate the structurally fragile element into the security substrate or security device. The reason for this is that in some embodiments, at least one of the security device and the security substrate is often located on the surface(s) of the security document and is therefore a point of attack by would-be counterfeiters / harvesters. Incorporating the structurally fragile element into the security substrate can improve harvesting resistance by causing the substrate to fail (i.e., break apart or fall apart) during harvesting. Furthermore, incorporating the structurally fragile element into the security substrate can improve the difficulty of separating the security device from an area in the security substrate that has the structurally fragile element. Alternatively, in some embodiments, the structurally fragile element is incorporated into at least the security device. Specifically, structurally fragile elements are strategically incorporated into the security device to create defect points / areas within the security device that make harvesting the security device increasingly difficult, if not impossible, without identifiable deformation of the security device, resulting in structural or optical defects. Those skilled in the art will appreciate that some security documents include window-like security devices, in which the security device is embedded within the security substrate during manufacture of the security substrate, forming a window-like area and a bridge. In such embodiments, it has been found to be advantageous to include a structurally fragile element across the bridge, thereby creating a structural impediment to harvesting attempts to the portion of the security device buried beneath the bridge. The portion of the security device buried beneath the bridge will be identifiable deformed if provided with a structurally fragile element.

[0047] The structurally weakened elements, in some embodiments, are strategically incorporated such that they are configured (e.g., sized, shaped, numbered, distributed, or positioned) in a manner that encourages at least one of structural or optical defects during a harvesting attempt. In some embodiments, the structurally weakened elements include a set of perforations. As used herein, the term "perforations" or "multiple perforations" encompasses holes that extend through at least a portion of the depth / thickness of a particular component or combination of components of the security document.

[0048] The perforations according to some embodiments of the present disclosure may take on various shapes and sizes and may be arranged in various patterns or randomly distributed in the anti-harvesting area. In certain embodiments, the perforations are arranged to define an anti-harvesting area separate from the remaining bulk area. As used herein, the term "anti-harvesting area" encompasses the area in, under, or over the security device in which the set of perforations is arranged, such as in the security substrate, in the security device, or in any other component of the security document. In other words, in some embodiments, the anti-harvesting area includes the location(s) where the arrangement of the set(s) of perforations overlaps with the security device. The perforations, in certain embodiments, are arranged such that a border region is formed between the bulk area and the anti-harvesting area. In some embodiments, it may be advantageous to arrange the perforations in a predetermined pattern. Surprisingly, embodiments in which the perforations are arranged in a pattern that tapers from either edge of the security device to the center, or from one side to the opposite side, have proven effective in inducing structural or optical defects in response to a harvesting attempt.

[0049] Perforations contemplated within the scope of the present disclosure may be of uniform size, shape, or depth across the anti-harvesting area, or they may vary in size across the anti-harvesting area. In certain embodiments, it may be advantageous for the perforations to be wide enough to create structural or optical defects in the event of harvesting, but visually undetectable, especially in reflected light. The perforations may allow light to escape (i.e., at least 1 / 2 the wavelength of the incident light), but be visually undetectable in at least one of reflected or transmitted light. In various embodiments, the set of perforations is preferably sized such that at least one of the perforations is less than 100 microns, less than 50 microns, or less than 35 microns. Reflected light viewing within the context of the present disclosure includes illuminating the security document or security device from one side and viewing the security device from the same side. Alternatively, transmitted light viewing includes illuminating the security document or security device from one side and viewing the security device from the opposite side.

[0050] The perforations defining the anti-harvest area may extend at a right angle or an oblique angle, or a combination thereof, in the anti-harvest area, according to various embodiments of the present disclosure. In certain embodiments, in light of the performance of having perforations extending at an oblique angle, it may be advantageous for the perforations to be less visually detectable. In certain embodiments, angled perforations are used when a set of perforations is incorporated into a security device. As used herein, the term "visually detectable" encompasses the characteristics of a feature that can be analyzed by the naked eye, while the term "visually undetectable" encompasses features that cannot be analyzed by the naked eye. For example, in one embodiment, the set of perforations is visually undetectable when the anti-harvest area is viewed in reflected light. In certain embodiments, not only are the set of perforations visually undetectable, but they are also positioned relative to the optically variable features such that they do not substantially interfere with the fidelity of the optically variable features in the anti-harvest area that matches the fidelity of the optically variable features in the bulk area. Oblique perforations are preferred in some embodiments because they reduce detection in transmitted light as well as reflected light when detection requires that the anti-harvest area be viewed at an oblique angle to the perforation, the angles referenced herein being made with respect to a plane parallel to the upper surface of the security device.

[0051] The set of perforations may be distributed in the anti-harvesting area in any predefined pattern in various embodiments according to the present disclosure. For example, it is contemplated that the perforations are arranged in a set of indicia that may serve as an additional element of authentication of the security document in some embodiments. More specifically, the set of perforations may be arranged to form letters, numbers, or symbols. For example, in an embodiment in which the security document is a bank note, the set of perforations is arranged in the form of numbers indicating the denomination of the bank note. Furthermore, it is contemplated that in some embodiments, the set of perforations extends through a single component of the security document, through multiple components, through only a portion of the depth of a single component, through a portion of the depth of multiple components, or any combination thereof. For example, in at least one embodiment, the perforations extend through only a portion of the depth of the security device. In certain embodiments, the set of perforations in the anti-harvesting area extends through the entire thickness of the security device and through the entire thickness of the security substrate. In certain embodiments that have been shown to exhibit superior anti-harvesting resistance, the set of perforations in the anti-harvesting area includes perforations that extend through at least 85% of the entire depth of the security device, and are at least 90%, 95%, 96%, 97%, 98%, 99%, or 100% deep of the depth / thickness of the security device.

[0052] In at least one embodiment, where the security device is a micro-optical security device comprising at least an array of focusing elements and an array of micro-image elements, it is expected that the set of perforations will be sized or arranged to provide a visually detectable indicia of authenticity. For example, in certain embodiments, the set of perforations will extend the entire depth of the focusing elements and serve to cut or remove these focusing elements, but not the underlying micro-image elements or other components that form part of the security device. For example, in at least one embodiment, the set of perforations includes at least one perforation having at least one lateral dimension that is greater than 100 microns, greater than 125 microns, or greater than 135 microns, and having a distinct feature, where the set of perforations renders the security device incapable of projecting a composite image (e.g., an optically variable feature) in the anti-harvesting area. In certain embodiments, the perforations can be characterized as cut out and can be combined or arranged in the form of various indicia, such as an image, a string of characters, an encoding, or a pattern. Although not required, in various embodiments, the cut out areas are aligned with one or more composite images in the anti-harvest or bulk area. In at least one embodiment, the cut out areas are larger than the perforations described above, but still small enough that they are individually visually undetectable in reflected light, but visually detectable in transmitted light. According to various embodiments, the cut out areas are visually detectable both individually and in combination in this embodiment when the security device is viewed in reflected light.

[0053] It is also contemplated herein that in certain embodiments of the present disclosure, the cut out regions may be combined with other artifacts of the security document, for example in at least one embodiment the cut outs forming the anti-harvesting areas are laminated with an ink or effects layer disposed on the security substrate.

[0054] The set of perforations may extend through a minor or major portion of the depth of the security document, or any component of the security document, or combination thereof. As used herein, the term "major portion" encompasses a thickness depth that is greater than 50% (up to and including 100% of) the thickness of the referenced security document or component of the security document. Conversely, in the context of the present disclosure, it is understood that the term "minor portion" encompasses a thickness depth that is 50% or less of the thickness of the referenced security document or component of the security document. For example, the set of perforations may extend through a major or minor portion of the thickness of the security device, a major or minor portion of the substrate, or a combination of the security device, security substrate, and any other interleaved (e.g., adhesive between the security substrate and the security device) or otherwise bonded component of the security document. Such partial depth perforations have been found to work well in certain embodiments according to the present disclosure in disguising the appearance of an anti-harvesting area. This is because the perforation may still not be visually detectable even in transmitted light. Such partial depth perforations may also be approximated by having a perforation tapered from one side of the security document, security substrate or security device towards the other side, in particular from the side of the security device where the anti-counterfeiting feature is to be observed. Furthermore, such an embodiment may be particularly suitable for manufacturability, since it may not be necessary to implement the manufacturing controls necessary to terminate the perforation within the depth / thickness of the security device or security substrate, as may be the case.

[0055] As discussed, the set of perforations may be uniform in dimensions or may vary in their dimensions (e.g., inner circumference, diameter, taper, depth, etc.) across the anti-harvesting area in some embodiments. Additionally, the distribution, size, and shape (e.g., lines, circles, trapezoids, triangles, stars, rhomboids, ovals, etc.) of the set of perforations may be uniform or variable across the anti-harvesting area in some embodiments. In at least one embodiment, all perforations within each of the anti-harvesting areas are uniform across those areas but distinct within the various anti-harvesting areas within the security device, such that a first anti-harvesting area has a first set of perforations and a second anti-harvesting area has a second set of perforations that differ in terms of shape, size, depth, or arrangement.

[0056] It should be understood that a security document may have multiple security devices, and that a security device may have multiple harvesting prevention areas, and a reference herein to a single harvesting prevention area of ​​a single security device should be understood to encompass multiple of the same.

[0057] While the anti-harvesting area is confined within the boundaries of the security device in various embodiments according to the present disclosure, it is also contemplated herein that the set of perforations defining the anti-harvesting area may extend beyond the edges of the security device. For example, in certain embodiments, the set of perforations forming the anti-harvesting area is supplemented by a set of perforations that extend beyond the anti-harvesting area on portions of the security substrate that are not overlapped by the security device. It is also contemplated herein that the perforations may be provided with tactile or tactile features that are easily detectable by a user or easily detectable by a machine. Alternatively, in one embodiment, the arrangement of the set of perforations may be arranged in a predefined periodicity such that the arrangement provides a tactile feature of authentication.

[0058] The set of perforations according to various embodiments of the present disclosure can be configured in various ways. In certain embodiments according to the present disclosure, the effective perforations are formed in a selection of components of the security document after the security device is bonded to the security substrate. Furthermore, it has been found that it is most suitable to use laser irradiation to form the set of perforations in either the security device, the security substrate, or other security document components. For example, in one embodiment, the perforations are generated using an infrared laser, such as a CO2 laser. In particular, when it is desired that the perforations are tapered, it is suitable to use a laser to form the perforations. The cuts described herein are also formed in exemplary embodiments by using a laser, such as a CO2 laser.

[0059] In certain embodiments, lasers, particularly high frequency excited, rapidly modulated CO2 lasers, have been shown to provide excellent power stability and control and are suitable for constructing security documents according to embodiments of the present disclosure, particularly those embodiments that use tapered perforations. According to some embodiments, the laser-formed perforations range in size from about 50 microns to about 400 microns in diameter at their widest opening and can achieve punching speeds of, for example, as high as 420,000 holes per second.

[0060] Security Documents Various alternative uses of security documents will become apparent to those skilled in the art upon subsequent consideration of this disclosure. For example, security documents contemplated within the scope of this disclosure include, but are not limited to, security documents such as identification documents (e.g., passports, government IDs, etc.), currency documents (e.g., checks, bank notes, etc.), or consumer product documents (e.g., labels, signs, tags, etc.).

[0061] In at least one embodiment, the security document comprises a security device that is a micro-optical security device, comprising an array of micro-sized image elements (i.e., image icons) and an arrangement of focusing elements disposed on or in a polymer substrate. The image elements and the arrangement of focusing elements may be separated by an optical spacer. In either case, the arrangement of image icons and focusing elements is configured such that the arrangement of image icons is viewed through the arrangement of focusing elements to project one or more composite images (i.e., optically variable features). In this embodiment, the micro-optical security device is affixed to the upper surface of the security substrate, and one or more perforations extend through the entire thickness of both the micro-optical security device and the underlying security substrate. The lower surface of the security substrate / document may be provided with a simple ink layer or an effect layer (e.g., a layer containing luminescent or optically variable particles) if such a layer does not interfere with the optical effects generated by the security device. The effect layer may serve as a publicly or mechanically detectable and, optionally, machine-readable security feature.

[0062] How to create security documentation In another aspect of the present disclosure, a method of forming a security document is provided. In certain embodiments according to the present disclosure, the method includes providing a security device coupled to a security substrate and incorporating a structurally fragile element into at least one of the security device and the security substrate. The structurally fragile element is incorporated in certain embodiments such that an anti-harvesting area and a bulk area are defined within the security device. The anti-harvesting area is configured to cause the security device or the security substrate to suffer at least one of a structural defect or an optical defect.

[0063] In certain embodiments, a method is provided for increasing or enhancing the harvesting resistance of a security document or security device, the method comprising attaching one or more structurally fragile elements to at least one of the security substrate or security device, the structurally fragile elements being configured to apply an optical or structural defect upon a harvesting attempt.

[0064] According to various embodiments, a laser is used to create the perforations after the security device (e.g., security thread or patch) is attached to the security substrate, either on the paper machine or earlier in the foil laying process using an offline stripe or patch attachment system, such as the system sold by LEONHARD KURZ Stiftung & Co. KG and Pasaban SA. In various embodiments, once the device is attached to the paper, laser punching, ablating, or cutting of the security device or security paper can maintain at least one of the optical or structural fidelity required to attach the device to the paper. After the anti-harvesting area is added, the security device or security substrate suffers optical or structural defects in response to a harvesting attempt, thereby preventing removal of the device in a single, reusable piece.

[0065] Structural / Optical Fidelity As used herein, optical fidelity encompasses the similarity of the optically variable effects observed in the anti-harvest area to the bulk area of ​​the security device. As used throughout this specification, the term "structural fidelity" encompasses the alignment of the anti-harvest area of ​​the security device to the bulk area or substrate of the security device. Structural fidelity, in some embodiments, is demonstrated by substantial alignment of the anti-harvest area of ​​the security device to the bulk area or substrate of the security device. Substantial alignment, as used in this disclosure, encompasses, at a minimum, when (i) the anti-harvesting area of ​​the security device has a width ranging from about 75% of the width of the bulk area of ​​the security device to about 125% of the width of the bulk area, more preferably about 80% to about 120%, and even more preferably about 90% to about 110%, or (ii) the perforations in the anti-harvesting area of ​​the security device extend beyond the boundaries of the security device such that the shape of the perforations in the anti-harvesting area are identical to the shape of the perforations extending into the substrate or are entirely within the substrate. For example, in at least one embodiment, the anti-harvesting area of ​​the security device has structural fidelity with the bulk area of ​​the security document such that the edges of the security device that cross the anti-harvesting area are substantially aligned with the bulk area of ​​the security device connected immediately adjacent to the security device such that there is no structural defect (i.e., the taper of the anti-harvesting area from the bulk area). In at least one embodiment, structural integrity is exemplified by perforations that extend beyond the boundaries of the security device, where the shape of the perforations in the anti-harvest area is identical in shape and size to perforations in the bulk area or in areas of the substrate adjacent to the anti-harvest area.

[0066] In various embodiments according to the present disclosure, the anti-harvesting area of ​​the security device has optical fidelity consistent with the adjacent bulk area, such that optically variable features present in the anti-harvesting area are also present in the bulk area without visually observable distortion. As used in this disclosure, the term "observable distortion" encompasses at least one change in effect, shape, size, color, or transparency of the image. Optical or structural fidelity is ensured in various embodiments by incorporating a structurally weakened element (e.g., a set of perforations) into the security device after it is bonded (e.g., directly and securely affixed to the security substrate). By incorporating a structurally weakened element after the security device is bonded to the security substrate, a process step of adjusting the tension of the security device is avoided if the perforations are already formed in the security device. The perforations may cause non-uniform deformation of the security device, resulting in more and irreversible deformation in the anti-harvesting area compared to the bulk area.

[0067] Certain embodiments of the present disclosure include methods for using one or more structural vulnerabilities attached to a security device or security document that create a flaw in the security device, causing the device to fail upon any attempt to harvest the security device from the security document.

[0068] Working Example The invention will now be described with reference to a security document in the form of a bank note. In the exemplary embodiment shown in FIG. 1A, a security document 10 (e.g., a bank note) 10 is provided, which comprises a micro-optical film material (i.e., a security device) 14 bonded to a security substrate 16. Referring to the non-limiting example of FIG. 1A, harvest resistance is provided by a set of perforations 12 that define an anti-harvest area 17 and a bulk area 19, the set of perforations 12 extending perpendicularly to a surface 14a of the micro-optical security device 14. According to various embodiments, the perforations of the set of perforations 12 extend through both the micro-optical security device 14 and the security substrate 16. In this exemplary embodiment, the micro-optical security device 14 comprises an array of non-cylindrical microlenses 14b arranged across an array of image elements 14c. In various embodiments of the present disclosure, an optical spacer 14d is disposed between the array of microlenses 14b and the array of image elements 14c, thereby causing the security device 14 to project one or more composite images (not shown).

[0069] FIG. 1B illustrates an example of a security document according to some embodiments of the present disclosure. Referring to the non-limiting example of FIG. 1B, a variation of the exemplary embodiment described in FIG. 1A is shown in which a set of perforations 12 extend at an oblique angle instead of at a right angle. In the non-limiting example of FIG. 1B, the security document 10 includes a micro-optical film 14 in the form of a stripe. The micro-optical film 14 is bonded to a security substrate 16 before the perforations 12 are applied, thereby providing structural fidelity between the anti-harvest area 17 of the security device and the bulk area of ​​the security device 19.

[0070] As previously discussed, when the security device is viewed in reflected light, the perforations 12 are visually undetectable. However, when viewed in transmitted light, the perforations are visually detectable at the same angle at which the perforations extend. According to certain embodiments, the on-off quality of visibility of the perforations 12 is particularly asserted when the perforations extend at oblique angles. According to some embodiments, the anti-harvest area 17 of the micro-optical security device 14 has optical and structural fidelity with the bulk area 19 of the security device.

[0071] FIG. 2 illustrates an example of a security document according to certain embodiments of the present disclosure. The perforations 12 are fairly wide and extend entirely through the focusing microlenses 18, serving to cut or remove these focusing elements 18 without cutting or punching the underlying components of the security document 10, such as the optical spacers 20 and the image icons 22. According to certain embodiments, the perforations 12 are shaped such that they do not affect the ability of the micro-optical security device 14 to project a composite image in these areas. The set of perforations 12 is configured such that in combination with the microlenses 18, the set of perforations 12 provides additional authentication in the form of visually detectable indicia. According to various embodiments, when the micro-optical security device 14 is viewed in reflected light, the cut-out areas may or may not be visually detectable. When viewed in transmitted light, the cut-out areas are visually detectable. Importantly, the anti-harvesting area 17 of the micro-optical security device 14 has optical and structural fidelity with the bulk area 19 of the security device.

[0072] Figure 3A illustrates an example of a security document 10 according to some embodiments of the present disclosure, in which a set of perforations extend at an oblique angle. With reference to the non-limiting example of Figure 3A, an alternative embodiment of the security document 10 of Figure 1A is shown. According to a particular embodiment, the perforations of the set of perforations 12 extend at right angles, but only through the thickness of the micro-optical security device 14 without affecting the underlying banknote component.

[0073] FIG. 3B illustrates a further example of a security document 10 according to various embodiments of the present disclosure. Referring to the non-limiting example of FIG. 3B, a variation of the security document 10 is shown, in which the perforations of the set of perforations 12 extend at an oblique angle through the device 14, but not through the underlying security document 10 components. According to certain embodiments, precise control of the laser intensity and focus allows punching or cutting only through the security device 14, and not through the underlying security document 10 components 16. Similarly, precise control of the laser intensity and focus can prevent undesired cutting into deeper layers when cutting from the opposite side. According to various embodiments, when the micro-optical security device 14 is viewed in reflected light, the perforations of the set of perforations 12 are visually undetectable. However, when viewed in transmitted light, the perforations are visually detectable at the same angle as the perforations of the set of perforations 12 extend. Importantly, the anti-harvesting area of ​​the security device has optical and structural fidelity with the bulk area of ​​the security device.

[0074] 4A illustrates an example of a security document 10 according to some embodiments of the present disclosure, where the perforations of the set of perforations 12 extend at a perpendicular angle through the entire thickness only of the underlying component 16 of the security document 10. Referring to the non-limiting example of FIG. 4A, the perforations of the set of perforations 12 extend at a perpendicular angle through the entire thickness only of the underlying component 16 of the security device 10 (e.g., a fibrous or polymeric security substrate).

[0075] 4B is a diagram illustrating an example of a security document 10 according to various embodiments of the present disclosure. Referring to the non-limiting example of FIG. 4B, the perforations of the set of perforations 12 extend at an oblique angle through the underlying structure 16 of the security document 10. In some embodiments, the perforations of the set of perforations 12 (e.g., the embodiment shown in the examples of FIG. 4A and FIG. 4B) are tapered such that they are wide at the interface with the micro-optical security device 14 and narrow toward the opposite side of the underlying structure 16. Importantly, the anti-harvesting area 17 of the micro-optical security device 14 has optical and structural fidelity with the bulk area 19 of the micro-optical security device 14.

[0076] FIG. 5 illustrates an example of a security document 50 according to various embodiments of the present disclosure. Referring to the non-limiting example of FIG. 5, the perforations of the set of perforations 12, 12' are in the form of a "dot matrix" in the shape of a dollar sign symbol. The perforations are contained within the boundary of the security device 14 and are in the form of non-linear lines that span the security device 14 and extend outside the boundary of the security device 14 towards the bulk of the underlying structure 16. According to certain embodiments, the dot matrix form of the set of perforations 12 and 12' adds an additional anti-counterfeiting feature by having a complementary pattern of perforations outside the security device 14 that directly correlates to the set of perforations within the boundary of the security device 14. As shown in this non-limiting example, the security device 14 has structural fidelity between the perforations 12 in the anti-harvesting area 17 of the security device and the bulk area 19 of the security device. There is also structural fidelity between the perforations 12' in the anti-harvesting area 17' and the perforations 12' in the bulk area 19' of the substrate. According to certain embodiments, a set of perforations in the security device are visually undetectable in reflected light but visually detectable in transmitted light, while the perforations outside the anti-harvesting area (i.e., in the security substrate) are visually detectable in both reflected and transmitted light.

[0077] FIG. 6 illustrates an example of a security document 60 according to some embodiments of the present disclosure. Referring to the non-limiting example of FIG. 6, the perforations 24, 26 of the security device 10 are formed with varying shapes to improve resistance to harvesting. In particular, the perforations 24 have a trapezoidal shape. This shape improves harvesting resistance since the security device will be permanently and easily deformed even upon slight attempts to harvest the security device 14, especially when force is applied to the anti-harvesting area. A line-shaped perforation 26 is also provided in the security device. This line-shaped perforation 26 extends through one edge of the security device and through the other edge, thereby requiring a potential harvester to remove multiple pieces of the security device to successfully harvest a single thread. The perforations may be in the form of a pattern selected from the group of (a) a dot matrix forming a complex or simple design, and (b) a simple shape in the form of one or more lines, which may be linear or non-linear. By extending across the entire width of security device 14, the line serves to cut security device 14 into smaller pieces, such as patches. According to certain embodiments, shaped perforations, such as perforations 24 and 26, may be provided in combination with other anti-harvesting features, such as those described with reference to the examples of Figures 1A-5 of this disclosure. In certain embodiments according to the present disclosure, the anti-harvesting area of ​​security device 60 has optical and structural fidelity with the bulk area of ​​the security device.

[0078] Figure 7 illustrates an example of a security document, in this case a bank note 28, according to various embodiments of the present disclosure. Referring to the non-limiting example of Figure 7, the perforations 12a and 12b may also be used to serialize the bank note 28. As shown in this non-limiting example, the perforations 12a and 12b extend into the body of the bank note 28, across the affixed security device 14. This not only adds a defect point to the device 14 and the bank note 28 that can be acted upon during a harvesting attempt, but also adds a unique pattern to the device and the bank note. Importantly, the anti-harvest area of ​​the security device 14 has optical and structural fidelity with the bulk area of ​​the security device.

[0079] FIG. 8 illustrates an example of a security document 80 according to certain embodiments of the present disclosure. Referring to the non-limiting example of FIG. 8, line-shaped perforations 30a, 30b, 32, and 34 are formed in the security device 14. As shown in the illustrative example of FIG. 8, the perforations 30a, 30b, 32, and 34 have an orientation relative to the underlying structure 16. Some of the perforations (30a, 30b) are oriented horizontally (i.e., along a first axis x), while the perforation 32 is oriented vertically (i.e., along a second axis y) and the perforation 34 is at an acute angle to the first axis. Some of the perforations (30a, 32) are contained within the limits of the device, while others (30b, 34) extend to and break the edge of the device. According to certain embodiments, the orientation of the perforations at an angle and placement of the perforations in various locations relative to the security device 14 can improve the likelihood of tear propagation if someone attempts to remove the device, and the visual impact and visibility of the affixed features can be improved by increasing the complexity of their shape or pattern. Importantly, the anti-harvest area of ​​the security device 14 has optical and structural fidelity with the bulk area of ​​the security device.

[0080] Examples of security documents according to various embodiments of the present disclosure include a security document having a security substrate, a security device, and a structurally fragile element, wherein the security device is coupled to the security substrate, and the structurally fragile element is incorporated into at least one of the security substrate or the security device, and wherein the structurally fragile element defines an anti-harvesting area and a bulk area, and wherein the anti-harvesting area has one or more of structural or optical fidelity with the bulk area.

[0081] Examples of security documents according to various embodiments of the present disclosure include a security document in which the security device is a micro-optical security device comprising an array of image elements and the structurally fragile element comprises a portion of the array of image elements.

[0082] Examples of security documents according to various embodiments of the present disclosure include security documents in which the structurally weak element includes a set of perforations.

[0083] Examples of security documents according to various embodiments of the present disclosure include security documents in which a set of perforations include perforations that extend either perpendicular or at an oblique angle to a plane parallel to the top surface of the security device.

[0084] Example security documents according to various embodiments of the present disclosure include a security document in which a set of perforations extend through at least a portion of the depth of the security device or security substrate.

[0085] Examples of security documents according to various embodiments of the present disclosure include security documents in which the security device is a micro-optical security device comprising an array of micro-sized image elements and an array of focusing elements disposed on or in a polymer substrate, the array of micro-sized image elements and the array of focusing elements being configured such that when the array of micro-sized image elements is viewed through the array of focusing elements, one or more composite images are projected.

[0086] Examples of security documents according to various embodiments of the present disclosure include security documents in which a set of punch holes extend through the entire security device or extend through a subset of the focusing elements, cutting out the focusing elements of the subset of the focusing elements and rendering the security device unable to project a composite image in those areas.

[0087] An example security document according to various embodiments of the present disclosure includes a security document having a set of perforations extending through a majority of the security substrate.

[0088] Examples of security documents according to various embodiments of the present disclosure include security documents in which all perforations within the anti-harvesting area have substantially the same shape and the same lateral dimension parallel to the surface of the security document, as well as the same axial dimension perpendicular to the surface of the security substrate.

[0089] Examples of security documents according to various embodiments of the present disclosure include security documents in which each perforation in the anti-harvesting area has substantially different shapes or different lateral dimensions parallel to the surface of the security substrate or different axial dimensions perpendicular to the surface of the security substrate.

[0090] An example security document according to various embodiments of the present disclosure includes a security document in which a set of perforations are entirely disposed within a security device.

[0091] An example security document according to various embodiments of the present disclosure includes a security document in which a set of perforations extend beyond the boundaries of the security device.

[0092] Examples of security documents according to various embodiments of the present disclosure include security documents, where the security document is a bank note.

[0093] Examples of security documents according to various embodiments of the present disclosure include a security document in which the security document is a bank note and the set of punch holes comprises a serial number relating to the bank note and extends across both the anti-harvesting area of ​​the security device and the boundary of the security device.

[0094] An example security document according to various embodiments of the present disclosure includes a security document in which a set of perforations form a visible pattern.

[0095] Examples of security documents according to various embodiments of the present disclosure include security documents where the set of perforations comprises one or more of line-shaped perforations or polygon-shaped perforations.

[0096] An example security document according to various embodiments of the present disclosure includes a security document in which a set of perforations forming an anti-harvesting area extends across the entire width of the security device and cuts the security device into smaller pieces.

[0097] While various embodiments of the present disclosure have been described above, it should be understood that these descriptions have been presented solely by way of example, and not limitation, and thus the breadth and scope of the present disclosure should not be limited by any of the exemplary embodiments.

[0098] Although the present disclosure has been described with respect to various embodiments, various modifications or variations may be suggested to those skilled in the art, and it is intended that the present disclosure encompass such modifications or variations as fall within the scope of the appended claims.

[0099] This disclosure should not be read as implying that any particular element, step, or function is an essential element, step, or function that must be included within the scope of the claims. Moreover, the claims are not intended to invoke 35 USC § 112(f) unless the express words "means for" are followed by a participle.

Claims

1. A security board (16); a security device (14) including an array of image icons, an optical spacer, and an array of focusing elements, the array of focusing elements projecting synthetically magnified images of image elements within the array of image icons, the array of focusing elements being disposed on the optical spacer; a structurally fragile element (12); the security device is coupled to the security board; the structurally weakened element includes a set of perforations extending through the array of focusing elements; the structurally fragile element is not visible in reflected light and is visible in transmitted light; A security document (10) in which the structurally fragile element visually complements the synthetically magnified image projected by the array of focusing elements.

2. 10. The security document of claim 1, wherein said set of perforations comprises perforations that extend either perpendicular or at an oblique angle to a plane parallel to a top surface of said security device.

3. The security document of claim 1 , wherein the set of perforations extends through a thickness of the security device or security substrate.

4. The set of perforations The security document of claim 1 , extending throughout said security device.

5. 3. The security document of claim 2, wherein the set of perforations extends through 50% or more of the thickness of the security substrate.

6. 2. The security document of claim 1, wherein all perforations of the set of perforations have substantially the same shape and the same lateral dimension parallel to the surface of the security document and the same axial dimension perpendicular to the surface of the security substrate.

7. 2. The security document of claim 1, wherein each perforation of the set of perforations has a different shape or a different lateral dimension parallel to a surface of the security substrate or a different axial dimension perpendicular to a surface of the security substrate.

8. The security document of claim 1 , wherein the entire set of perforations is disposed within the security device.

9. The security document of claim 1 , wherein the set of perforations extends beyond the boundaries of the security device.

10. 2. A security document according to claim 1, wherein said security document is a bank note.

11. 2. The security document of claim 1, wherein the security document is a bank note and the set of punch holes comprises a serial number for the bank note and extends across both the security device and an area not comprising the security device.

12. The security document of claim 1 , wherein the set of perforations forms a visible pattern.

13. 2. The security document according to claim 1, wherein said set of perforations comprises one or more of line-shaped perforations (26) or polygon-shaped perforations (24).

14. The security document of claim 2 , wherein the set of perforations extends across the entire width of the security device.

15. providing a security device (14) including an array of image icons, an optical spacer, and an array of focusing elements, said array of focusing elements projecting synthetically magnified images of image elements within said array of image icons, said array of focusing elements disposed on said optical spacer, said security device (14) coupled to a security substrate (16); incorporating into said security device or said security substrate a structurally fragile element (12) that includes a set of perforations extending through said array of focusing elements.

16. A security document formed according to the method of claim 15.

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