阅读说明：本技术 全微光学安全文件 (All-micro-optical security document ) 是由 S·M·卡派 K·默克-汉密尔顿 F·范布利克森-芬纳克 J·范古姆斯特 J·科万 R·图 于 2019-09-10 设计创作，主要内容包括：一种安全文件(200),包括安全基材(205)。所述安全基材包括观察侧(209)和背衬侧(211),以及在所述观察侧上提供光学可变效果(OVE)(513)的微光学系统(305,321)。所述安全文件还包括保护层(225)和掩模层(215),所述掩模层(215)设置在所述保护层与所述安全基材的所述背衬侧之间。(A security document (200) comprising a security substrate (205). The security substrate comprises a viewing side (209) and a backing side (211), and a micro-optical system (305, 321) providing an Optically Variable Effect (OVE) (513) on the viewing side. The security document further comprises a protective layer (225) and a masking layer (215), the masking layer (215) being disposed between the protective layer and the backing side of the security substrate.)

1. A security document (200) comprising:

a security substrate (205) comprising a viewing side (209) and a backing side (211), and a micro-optical system (305, 321) providing an Optically Variable Effect (OVE) (513) on the viewing side;

a protective layer (225); and

a mask layer (215), the mask layer (215) being disposed between the protective layer and the backside of the security substrate.

2. The security document of claim 1, wherein the protective layer comprises a second security substrate (465).

3. The security document of claim 1 wherein the mask layer comprises a layer of opacifying material.

4. A security document as claimed in claim 1 in which the masking layer comprises a layer of reflective material.

5. The security document of claim 1 wherein said mask layer comprises a window (217).

6. The security document of claim 5, further comprising:

a patch (245), the patch (245) comprising an authenticity optical marking (247),

wherein the patch is visible through the window of the mask layer.

7. The security document of claim 6, wherein the authentic optical indicia provided by the patch comprises at least one of a watermark, an offset design, a gravure design, or an optical security device.

8. The security document of claim 1, further comprising:

a tactile feature (445, 455, 460), the tactile feature (445, 455, 460) disposed on the viewing side of the security substrate.

9. The security document of claim 8, wherein the tactile feature (445) comprises a material printed on the viewing side of the security substrate.

10. The security document of claim 9, wherein the tactile feature comprises intaglio printing on the viewing side of the security substrate.

11. The security document of claim 1, wherein the security substrate comprises:

a focusing element layer (409);

an image icon layer (413); and

an optical spacer (415) is provided,

wherein the focusing element layer is disposed on a first side of the optical spacer, an

Wherein the image icon layer includes image icons disposed proximate to a focal point of focusing elements of the focusing element layer.

12. The security document of claim 11, wherein the focusing element layer comprises refractive focusing elements.

13. The security document of claim 11, wherein the focusing element layer comprises a reflective focusing element.

14. The security document of claim 11 wherein the image icon layer is disposed on a second side of the optical spacer.

15. The security document of claim 11, wherein the optical spacer is integral with the focusing element layer.

16. The security document of claim 11, wherein the image icon layer is integral with the focusing element layer.

17. The security document of claim 16, wherein the image icons in the image icon layer are provided as relief structures in the focusing elements of the focusing element layer.

18. The security document of claim 11, further comprising:

a sealing layer (450), the sealing layer (450) disposed on the viewing side of the security substrate.

19. The security document of claim 18, further comprising a tactile feature (460), the tactile feature (460) being provided as a variation in the thickness of the sealing layer.

20. The security document of claim 11 wherein the optical spacer comprises a transparent polymeric sheet.

21. The security document of claim 20, wherein the transparent polymer comprises at least one of polyethylene terephthalate (PET), biaxially oriented polypropylene, polycarbonate, polyester, polypropylene, or polyvinyl chloride (PVC).

22. The security document of claim 1 wherein said OVE includes a moire magnification effect.

23. The security document of claim 1, wherein the security substrate comprises a region exhibiting overall transparency, wherein the overall transparency allows static features disposed on or below the backing side of the security substrate to be visible through the viewing side of the security substrate.

24. The security document of claim 23, further comprising:

a static feature printed on the backing side of the security substrate.

25. The security document of claim 23, further comprising:

a static feature provided as a color change in the mask layer.

26. The security document of claim 1, wherein the mask layer and the protective layer are provided as a single layer of material coupled to the backing side of the security substrate.

27. The security document of claim 1, further comprising:

a machine readable security feature (473).

28. The security document of claim 1, further comprising a tactile feature,

wherein the tactile features are registered with one or more of windows in the mask layer, a patch, features of a printed layer, or the OVE.

Technical Field

The present disclosure relates generally to security documents (e.g., banknotes) that provide significantly enhanced resistance to the collection of difficult-to-copy security features (e.g., micro-optical features) for the production of counterfeit banknotes.

Disclosure of Invention

The present disclosure provides an all-micro-optical security document.

In a first embodiment, a security document includes a security substrate having a viewing side and a backing side, and a micro-optical system providing an Optically Variable Effect (OVE) on the viewing side. The security document further comprises a protective layer and a mask layer disposed between the protective layer and the backing side of the security substrate.

Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

Definitions for certain other words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words or phrases.

Drawings

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

fig. 1 illustrates, in a background manner, at least one technical problem addressed in accordance with certain embodiments of the present disclosure;

fig. 2 illustrates an example of a security document according to various embodiments of the present disclosure;

fig. 3 illustrates an example of a security substrate according to certain embodiments of the present disclosure;

fig. 4A-4H illustrate examples of security documents according to some embodiments of the present disclosure; and is

Fig. 5 illustrates an example of a security document according to at least one embodiment of the present disclosure.

Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "couple" and its derivatives refer to any direct or indirect communication or interaction between two or more elements, whether or not those elements are in physical contact with one another. The terms "send," "receive," and "communicate," as well as derivatives thereof, encompass both direct and indirect communication. The terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation. The term "or" is inclusive, meaning and/or. The phrase "associated with … …" and derivatives thereof is intended to include, be contained within … …, be interconnected with … …, contain, be contained within … …, be connected to or with … …, be coupled to or with … …, be in communication with … …, cooperate with … …, be interleaved, juxtaposed, proximate to, incorporated into or in conjunction with … …, have the nature of … …, have a relationship with or to … …, and the like. The term "controller" means any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase "at least one of … …," when used with a list of items, means that different combinations of one or more of the listed items can be used, and only one item in the list may be required. For example, "at least one of A, B and C" includes any one of the following combinations: A. b, C, A and B, A and C, B and C and a and B and C.

Definitions for certain other words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words or phrases.

Detailed Description

Figures 1 through 5, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged payment device.

With the background and disclosure of at least one technical problem addressed according to certain embodiments of the present disclosure, fig. 1 shows an example 100 of a mechanism by which the security features of one authentic security document 105 (in this example, a banknote) can be collected and used to provide a malicious actor with two counterfeit security documents of usable quality.

Referring to the example of fig. 1, an example of a security document 105 is provided. As shown, the security document 105 includes a substrate 107 incorporating a plurality of structural features that provide visible and invisible indicia of the authenticity of the security document 105. Examples of construction features that provide invisible indicia of the authenticity of the document include, but are not limited to, magnetic ink or machine-readable features (e.g., radio frequency identification ("RFID")) antennas attached to or embedded in the substrate 107.

Examples of construction features of the visible indicia that provide authenticity include watermarks, printed effects, specialty inks, and security devices formed in, applied to, or embedded in the substrate 107. In this illustrative example, the structural features of the visible indicia of the security document 105 that provide authenticity include a watermark 109, which in some embodiments, the watermark 109 is formed by using a patterned watermark roll during the process of making the paper of the substrate 107. Additional examples of construction features of the security document 105 that provide visual indicia of authenticity include: a gravure design 111, the gravure design 111 comprising a difficult to replicate line pattern that produces a characteristic moire interference effect and has a unique surface texture due to the fine resolution of the pattern and the use of gravure printing techniques. In this illustrative example, the constructional features of the security document 105 that provide visual indicia of the authenticity of the document include regions 113 printed with a dedicated, difficult to obtain ink (such as an optically variable ink or a colour shifting ink), the appearance of the regions 113 changing in response to changes in the angle of incidence of light striking the ink. The constructional features of the visible indicia providing authenticity of the security document 105 may also include a security device 115. In some embodiments, the security device 115 comprises thin sections of material (e.g., narrow strips of polymer substrate) supporting one or more arrays of micro-or nano-scale optical structures (e.g., lenses, iconic structures, or diffraction gratings) that collectively produce a unique optical effect. Examples of such optical effects include, but are not limited to, optically variable effects such as moire magnification effects (sometimes referred to as "synthetically magnified images" or "synthetic images"), integrated imaging effects, color shifts, or holograms.

Improvements in imaging and printing technology and criminal intelligence provide malicious actors with the ability and materials to produce counterfeit security documents built around paper substrates, thereby providing a viable imitation of many of the above-described construction features that provide a visible indication of the authenticity of the security document disposed on the substrate 107. Given the small scale of the optical structures in security device 115 and the institutional controls over certain tools, materials, and techniques involved in producing security device 115, most malicious actors do not currently have the means or know-how to emulate security device 115.

As a variation of being unable to duplicate the security device 115, a malicious actor who expects to produce counterfeit security documents is directed to "collect" the security device from the authentic document, with the goal of incorporating portions of the collected security device into one or more counterfeit security documents. Referring to the illustrative example of fig. 1, security device 115 is a micro-optic line spanning the width of security document 100. As shown, the security device 115 is embedded in the substrate 107 such that portions of the security device 115 are visible through windows 117 in the substrate, while other portions of the security device are hidden by the bridge 119.

Referring to the illustrative example of fig. 1, in some instances, a malicious actor removes security device 115 substantially completely by soaking security document 100 in a solvent (e.g., water or bleach) for a long period of time to release the adhesive bond between security device 115 and substrate 107 or to break down substrate 107. Once substantially completely removed, the security device 115 may be carefully cut 130 into small pieces that may be attached to the surfaces of a plurality of counterfeit substrates 140a and 140b, or alternatively to the surfaces of the embedded carrier threads, to create a large number of counterfeit documents from an initial number of authentic security documents that, although not perfect copies of the security document 105, carry sufficient visual indicia of authenticity to be readily circulated and mistaken by many users as authentic documents.

Although not discussed in the illustrative example of fig. 1, other methods of producing counterfeit security documents may be implemented by collecting substantially complete security devices 115. For example, once collected, the security device 115 may be upgradeable to produce counterfeit banknotes of a higher denomination than the security document 105. Alternatively, where the security document is an identification document or is otherwise associated with an authorized actor, collecting substantially the entire security device 115 may facilitate creation of a counterfeit security document (e.g., creation of a fake passport) associated with an unauthorized actor.

As shown in the illustrative example of fig. 1, the collected operational assumptions include at least the assumption that the optical security device can be separated from the substrate, and the assumption that the structural features of the substrate that provide visual indicia of the authenticity of the security document can be copied by malicious actors. As discussed herein, these operational assumptions are reversed in accordance with certain embodiments of the present disclosure by providing a security document constructed around a security substrate comprising a section of material exhibiting flexibility and tensile strength suitable for the application and at the same time providing an optical effect (such as an optically variable effect) that is difficult to replicate. As such, certain embodiments according to the present disclosure provide at least the following technical and practical benefits: deprives malicious actors of the opportunity to create counterfeit documents by applying components collected from real documents to counterfeit substrates of a quality available in criminals.

Fig. 2 illustrates, in an exploded view, elements of a security document 200 incorporating a security substrate, according to various embodiments of the present disclosure. Although fig. 2 illustrates a banknote as an example of a security document according to various embodiments of the present disclosure, embodiments according to the present disclosure are not limited thereto. Examples of security documents according to the present disclosure include, but are not limited to, identification documents (e.g., driver's licenses), authentication tags on counterfeit target products (e.g., handbags or watches), or financial documents (e.g., bankbook tickets or other negotiable instruments). In this illustrative example, the components numbered 205, 215, 225, 235, 245, and 255 in the figure control aspects of the appearance of the security document 200 when viewed from above (e.g., facing element 255 in fig. 2).

Referring to the non-limiting example of fig. 2, the security document 200 includes a security substrate 205 (e.g., the security substrate 300 in fig. 3), which security substrate 205 provides an optical effect based on an authentication microstructure, and at the same time is suitably flexible, durable, and strong to act as a structural anchor for the security document 200. According to certain embodiments, the security substrate 205 comprises a sheet of material having microstructures that create an optical effect that serves as a visual indicia of the authenticity of the security document 200. In some embodiments, the microstructures create an Optically Variable Effect (OVE), such as a moir é magnification effect (also sometimes referred to as a "synthetic image" or "synthetic magnified image") of icon microstructures, a motion effect (where the synthetic image appears to "shift" or change appearance relative to a change in viewing angle), or a color shift effect. As shown in the illustrative example of fig. 2, in certain embodiments, the microstructures that create the optical effect comprise microscale focusing elements (e.g., focusing element 207). According to an embodiment, the focusing element 207 is a refractive focusing element (e.g., a microlens having a plano-convex profile, a concave profile, or a flat profile, such as a gradient index ("GRIN") lens). In some embodiments, the focusing element 207 is a reflective focusing element (e.g., a micro-scale concave mirror). In some embodiments, the microstructures on the security substrate 205 are diffractive microstructures that produce a diffraction-based effect (e.g., a color effect produced by a diffraction grating in the security substrate 205).

In some embodiments, security substrate 205 comprises a viewing side 209 (visible in fig. 2) and a backing side 211 (not visible in fig. 2) opposite viewing side 209.

As shown in the illustrative example of fig. 2, the security document 200 includes a masking layer 215, the masking layer 215 being disposed between the protective layer 225 and the backing side 211 of the security substrate 205. According to various embodiments, the mask layer 215 comprises a sheet of material or applied coating that blocks the view of some or all of the printed layer 235, the security substrate 205, and the tactile layer 255 from the perspective of the underside 227 facing the protective layer 225. In certain embodiments, the mask layer 215 comprises a layer of opacifying material (such as a coating or opaque film) having a color selected to enhance the visibility of the optical effect produced by the security substrate 205. In some embodiments, mask layer 215 has a color selected to contrast with other features (e.g., the color used in print layer 235). In embodiments where the security substrate 205 produces a moire magnification effect, a light color (e.g., white) may be particularly suitable for opacifying the mask layer 215. In certain embodiments, the mask layer 215 comprises a layer of reflective material, such as a metal coating or an applied foil.

In certain embodiments, the mask layer 215 includes a window 217 through which light entering the security document 200 through the underside 227 of the protective layer 225 can pass to the security substrate 205. In various embodiments, a patch 245 is disposed in the window 217. According to various embodiments, the patch 245 comprises a section of material (e.g. a fibrous material such as currency paper, a polymeric material or a metallic material) which provides the security document 200 with a further optical indicium of authenticity and is visible from one or both sides of the security document 200. As shown in the illustrative example of fig. 2, in some embodiments, the additional authentic optical indicia provided by the patch 245 is a watermark 247. In some embodiments, the additional authentic optical indicia provided by the patch 245 is a printed design (e.g., an offset or intaglio printed design) or another optical security device (e.g., a hologram). In this manner, the window 217 and patch 245 facilitate the incorporation of recognized security features from conventional security documents in which the optical security device is a separate component from the substrate into a security document according to the present disclosure that is constructed around the security substrate 205. As a practical example, a user who has authenticated a banknote for decades by checking whether there is a properly formed watermark may similarly authenticate the security document 200.

In some applications, it may be advantageous to construct security document 200 such that all of the visual information of the document is provided as an optical effect, particularly where compatibility with conventional document processing machines (e.g., bill readers in vending machines) or the adoption of older security documents by users familiar with such documents is not a significant bottleneck problem. However, in some applications, it is appropriate that a portion of the visual information provided by the security document 200 is provided as a static (no change in appearance with respect to viewing angle or lighting conditions) feature. Examples of visual information that may be advantageous to provide as a static feature include, but are not limited to, printed features that extend over traditional security features (to facilitate backwards compatibility with existing document processing systems), and alphanumeric text that provides basic information (such as denomination, address, or serial number) (to facilitate machine readability of such information and to reduce eye strain on a human reader).

Referring to the non-limiting example of fig. 2, the security substrate 205 includes one or more regions exhibiting overall transparency. As used in this disclosure, the term "overall transparency" encompasses the property of providing static features on or below the backing side 211 of the security substrate at a macroscopic level that is visible through the viewing side 209 (i.e., presented in a proportion that is visible to the human eye). In certain embodiments according to the present disclosure, such as in certain embodiments in which the security substrate 205 uses a layer of refractive focusing elements to provide a moir é magnification effect of the micro-scale iconic features in the icon layer, the micro-scale iconic and lens features make the entire security substrate 205 very transparent.

According to some embodiments, static features visible through very transparent regions of the security substrate 205 are provided in the printed layer 235 applied to the backing side 211 of the security substrate 205. In some embodiments according to the present disclosure, the static features (e.g., geometric pattern 237 and indicia 239) are printed using one or more printing techniques suitable for making security documents, including, but not limited to, offset printing, flexographic printing, gravure printing, or inkjet printing. In some embodiments, the features of print layer 235 are applied in registration with one or more of the optical effects provided by security substrate 205, window 217, patch 245, or tactile layer 255. In some embodiments, print layer 235 is applied to the backside of security substrate 205, and mask layer 215 is subsequently applied. In some embodiments, printing layer 235 and mask layer 215 comprise a single integral layer.

Referring to the non-limiting example of fig. 2, in some embodiments, the security document 200 includes a tactile layer 255, the tactile layer 255 including features applied to the viewing side 209 of the security substrate 205 and the features being touchable by a user handling the security document 200. According to some embodiments, the tactile layer 255 comprises a transparent sealing layer covering the viewing side 209 of the security substrate 205. In some embodiments (e.g., like embodiments in which the viewing side 209 of the security substrate 205 has a substantially non-planar surface (e.g., a concave-convex surface with plano-convex microlenses)), the sealing layer may improve the overall performance of the security document by filling gaps between the lenses in which contaminants may accumulate and reduce the ability of the security substrate 205 to provide an optical effect. In some embodiments where tactile layer 255 comprises a transparent sealing layer, tactile features (e.g., text 257 and denomination number 259) may be provided by printing material on the surface of the sealing layer (e.g., using gravure printing that creates a characteristic surface texture). In various embodiments, where the tactile layer 255 includes a transparent sealing layer, the tactile features can be provided by creating (e.g., by embossing) a thickness variation of the sealing layer. In certain embodiments, where the tactile layer 255 does not include a transparent sealing layer, the tactile features are created by printing the material directly onto the viewing side 209 of the security substrate 205. According to various embodiments, the tactile features (e.g., features 257 and 259) of tactile layer 255 are formed in registration with one or more of the optical effect provided by security substrate 205, the feature of print layer 235, window 217, or patch 245.

As shown in the illustrative example of fig. 2, the security document 200 includes a protective layer 225. According to various embodiments, the protective layer 225 comprises a single or multi-layer structure that protects the thin structure (e.g., the reflective foil used as the mask layer 215) or delicate structure (e.g., the patch 245) of the security document from abrasion and exposure to destructive contaminants. In some embodiments, the protective layer 225 comprises a sheet of material (e.g., a thin polymer film or a fibrous material, such as paper) that is adhered to the mask layer 215. In various embodiments according to the present disclosure, the protective layer 225 comprises an applied coating of a suitably durable material (e.g., a photocurable resin suitable for creating the sealing layer 340 in fig. 3). In some embodiments, the protective layer 225 is integral with the mask layer 215 (e.g., a single layer of the same material). According to certain embodiments, the protective layer 225 comprises a multilayer structure (e.g., as shown in fig. 4H and 5 of the present disclosure) configured around the second security substrate.

Fig. 3 illustrates structural aspects of an example of a security substrate 300 according to various embodiments of the present disclosure. For reference, fig. 3 is oriented such that the viewing side 301 of the security substrate appears near the top of the figure, while the backing surface 303 appears at the bottom of the figure.

Referring to the non-limiting example of fig. 3, in certain embodiments, the security substrate 300 includes a plurality of focusing elements 305 (including, for example, focusing elements 307) and an image icon arrangement 321 (including, for example, image icons 320). According to various embodiments, each focusing element of the plurality of focusing elements 305 has a footprint in which one or more image icons of the image icon arrangement 321 are positioned proximate to a focal point of the focusing element such that, at certain viewing angles, the focusing element focuses on the image icon. Collectively, the focusing elements in the plurality of elements 305 magnify portions of the image icon arrangement 321 to produce a moire magnification effect (also referred to as a "synthetically magnified image" or, more succinctly, a "synthetic image"), wherein individual microscopic image icons are collectively magnified by the plurality of focusing elements 305 to produce an image that dynamically reacts (e.g., by appearing to move or change color) in response to a shift in viewing angle. In some embodiments, in combination with the moire magnification effect described above, a plurality of focusing elements 305 may operate with the image icon arrangement 321 to produce a unitary image. As used in this disclosure, the term "unified image" encompasses a visual effect produced by, for example, a micro-optics system based on processing a set of viewpoint images to produce an image layer that is used to define the configuration of the image icon arrangement 321 or a portion thereof. In accordance with certain embodiments of the present disclosure, WIPO publication WO 2013/163287 entitled "Security Device For Projecting a Collection of Synthetic Images" provides a non-limiting example of a unified image. For many malicious actors, it is difficult, if not impossible, to replicate the moire magnification effect described above, which in many cases is a trusted visual indicia of the authenticity of a security document constructed around the security substrate 300.

According to certain embodiments, the plurality of focusing elements 305 comprises a planar array of micro-optical focusing elements. In some embodiments, the focusing elements of the plurality of focusing elements 305 comprise micro-optic refractive focusing elements (e.g., plano-convex lenses or GRIN lenses). In some embodiments, the refractive focusing elements of the plurality of focusing elements 305 are produced from a photocurable resin having a refractive index in the range of 1.35 to 1.7 and a diameter in the range of 5 μm to 200 μm. In various embodiments, the focusing elements of the plurality of focusing elements 305 comprise reflective focusing elements (e.g., very small concave mirrors) having diameters in the range of 5 μm to 50 μm. Although the focusing elements of the plurality of focusing elements 305 are shown to comprise circular plano-convex lenses in this illustrative example, other refractive lens geometries (e.g., biconvex lenses) are possible and within the intended scope of the present disclosure.

As shown in the illustrative example of fig. 3, the image icon 320 arrangement includes a set of image icons (including image icon 321) positioned at predetermined locations proximate to the focus of the focusing elements of the plurality of focusing elements 305. According to various embodiments, each of the image icons 320 arrangement includes a region of light curable material associated with a focusing path of structured light (e.g., collimated UV light) light through the plurality of focusing elements 305 from a projection point associated with one or more predetermined ranges of viewing angles. In some embodiments, each image icon in the arrangement of image icons 320 is disposed within a structured image icon layer that includes structures for holding a volume of pigmented material. In some embodiments, individual image icons in the arrangement of image icons 320 are not disposed within the structured image icon layer. As used in this disclosure, the term "structured image layer" encompasses a layer of material (e.g., a photocurable resin) that has been embossed or otherwise formed to include structures (e.g., recesses, posts, grooves, or mesas) for positioning and retaining image icon material. According to various embodiments, the individual image icons of the arrangement of image icons 321 are disposed within a structured image layer that includes one or more of voids, mesas, or posts that act as retaining structures to retain the micro-scale and nano-scale volumes of chromonic material. In some embodiments, the image icons of the image icon layer 321 are formed by: the light curable material is directionally cured by the plurality of focusing elements 305 to control the viewing angle at which the focal point of the focusing elements falls on the image icons and the viewing angle at which a particular optical effect is made visible by expansion.

As shown in the illustrative example of fig. 3, in certain embodiments, the security substrate 300 includes an optical spacer 310. According to various embodiments, optical spacer 310 comprises a film of substantially transparent material that operates to position an image icon in an arrangement of image icons 320 within or about a focal plane of a focusing element of the plurality of focusing elements 305. In certain embodiments according to the present disclosure, optical spacer 310 comprises a fabrication substrate onto which one or more layers of photocurable material may be applied to form one or more of the image icon 320 arrangement or plurality of focusing elements 305. In certain embodiments according to the present disclosure, the optical spacer 310 does not include a structure separate from the plurality of focusing elements 305, but is integrally formed (e.g., by casting) with the plurality of focusing elements 305.

According to various embodiments, the security substrate 300 includes one or more regions of light curable protective material 330, the one or more regions of light curable protective material 330 occupying the spaces between the image icons in the arrangement of image icons 320. In some embodiments, the arrangement of image icons 320 is first formed (e.g., by selectively curing and removing liquid light curable material on the optical spacer 310), and then a layer of clear light curable material is applied to fill the spaces between the image icons in the arrangement of image icons 320, and then flood cured to form a protective layer that protects the image icons from movement from their position within the footprint of the focusing element of the plurality of focusing elements 305. In certain embodiments, the light curable material used to form the image icon 320 arrangement is a colored Ultraviolet (UV) curable polymer.

In certain embodiments according to the present disclosure, the security substrate 300 comprises a sealing layer 340 on the viewing side 301 of the security substrate 300. According to certain embodiments, the sealing layer 340 comprises a thin (e.g., 2 μm to 50 μm thick layer) substantially clear material interfacing with the focusing elements of the plurality of focusing elements 305 on a lower surface, and comprises an upper surface having less curvature variation than the plurality of focusing elements 305 (e.g., by being smooth or by having a surface with local undulations having a radius of curvature greater than that of the focusing elements).

Although fig. 3 provides one example of a security substrate 300 according to various embodiments, the present disclosure is not so limited. For example, although in fig. 3, the image icon arrangement 321 is shown as being structurally different from the plurality of focusing elements 305, in some embodiments, the focusing elements and image icons may be disposed in a single layer. For example, in some embodiments, the image icons may be provided as relief structures or "indentations" that are selectively positioned on the surface of an array of convex lenses (sometimes referred to as "grewhat" lenses). As another example, in embodiments incorporating reflective focusing elements, the image icons may be provided as color regions in a "layer" between the reflective surfaces of the focusing elements. In such embodiments, the image icons and focusing elements may be disposed on a single side of the optical spacer, as opposed to the example of fig. 3, where the image icons 320 and focusing elements 307 occupy different sides of the optical spacer 310 in fig. 3.

Fig. 4A-4H illustrate examples of security documents constructed using a security substrate according to various embodiments of the present disclosure. The examples discussed with reference to fig. 4A-4H illustrate a wide range of potential configurations of security documents constructed around one or more security substrates according to embodiments of the present disclosure. Additional embodiments and configurations other than those described with reference to fig. 4A-4H are within the intended scope of the present disclosure. For convenience, structural elements that are common to more than one figure are similarly numbered.

Referring to the non-limiting example of fig. 4A, a security document 400 is shown in accordance with various embodiments of the present disclosure. In some embodiments according to the present disclosure, a security document 400 includes a security substrate 405 (e.g., security substrate 300 in fig. 3), a protective layer 430, and a mask layer 420 disposed between a backing side 403 of the security substrate 405 and the protective layer 430, the security substrate 405 having a viewing side 401 and a backing side 403. According to certain embodiments, the security substrate 405 comprises micro-scale optical structures that produce an optical effect on the viewing side that is an optical signature of the authenticity of the security document 400.

According to certain embodiments, the security substrate 405 provides an optically variable effect, such as a moire magnification effect, by the pattern of focus of the focusing elements (e.g., focusing elements 407) in the focusing element layer 409 incident relative to the image icons (e.g., image icons 411) in the image icon layer 413. In some embodiments, the security substrate 405 includes an optical spacer 415. As shown in the illustrative example of fig. 4A, optical spacer 415 comprises a carrier film having a first side and a second side. According to some embodiments, the focusing element layer 409 is disposed on a first side of the optical spacer 415 and the image icon layer 413 is disposed on a second side of the optical spacer 415. In some embodiments, both the focusing element layer 409 and the image icon layer are disposed on the same side of the optical spacer 415. In various embodiments, one or more of the optical spacer 415, focusing element layer 409, and image icon layer 413 are integral with one another, such as by being iteratively constructed in a common material (e.g., photocurable polymer) layer.

While in the illustrative example of fig. 4A, the security document 400 has been discussed with respect to an embodiment in which the security substrate 405 includes optical microstructures that provide optically variable effects (e.g., moire magnification effects), other embodiments are within the contemplation of the present disclosure including security substrates whose microstructures produce different optical effects (e.g., interference-based effects or diffractive effects), which are embodiments of security documents directed to the assumption of flipping the structural backbone of the security document, which are substrates from which components comprising optical effect producing microstructures can be separated.

Referring to the non-limiting example of fig. 4A, the mask layer 420 comprises a thin layer of material (e.g., an applied layer or coating or a reflective or opaque film of material) that limits the visibility of structures disposed between the mask layer and the viewing side 401 of the security substrate from the underside of the security document. According to various documents, the security document 400 further includes a protective layer 430, which protective layer 430 may be, according to embodiments, one or more layers of material that operate to shield structures between the mask layer 420 and the viewing side 401 of the security substrate from contact with objects or solvents that may damage or degrade the microstructures of the security substrate 405 (e.g., image icons 411) or other security features and visual information of the security document 400 (e.g., a watermark applied in a window of the mask layer 430). In some embodiments, protective layer 430 comprises a sheet of polymeric (e.g., biaxially oriented polypropylene) or fibrous (e.g., currency paper) material.

As noted elsewhere in this disclosure, constructing the security document around the security substrate 405 allows for the replacement of a wide range of constructs and features that may be incorporated into the security document, the security substrate 405 both providing a signature optical effect that is difficult for most (if not all) malicious actors to replicate through the microstructure of the security substrate itself) and at the same time providing a structural basis for the security document as a whole. Fig. 4B shows an example of additional features (in this case, windows and patches) that may be incorporated into a security document according to various embodiments of the present disclosure.

Referring to the non-limiting example of fig. 4B, in some embodiments, a window 423 is provided in the mask layer 420. In certain embodiments according to the present disclosure (e.g., embodiments in which the mask layer 420 is an applied coating), the window 423 is formed by not applying a coating to the backing side 403 of the security substrate 405. In some embodiments, the window 423 (e.g., preformed as an aperture in a reflective or opaque film applied to the backside 403 of the security substrate 405. according to some embodiments, the window 423 is formed in registration with an area 427 of the security substrate 405 that exhibits overall transparency that allows static features of a certain dimension to be visible through the viewing side 401 of the security substrate 405 that are observable by the naked eye. depending on the configuration of the security document 400, the window 423 itself may be a feature of the security document 400. as an illustrative example, in embodiments where the protective layer 430 is transparent, the window 423 allows light to pass through the entire security document 400, the window 423 itself may be a very distinctive feature of certain security documents (such as banknotes) that are generally opaque across its entire surface area.

In some embodiments, window 423 operates to facilitate the inclusion of material patch 425 to provide additional optical indicia of authenticity. According to certain embodiments, the authentic optical indicia provided by the patch 425 is at least one of a watermark, a printed design (e.g., a design printed using offset or intaglio printing), or another optical security device (such as a hologram), or an optical security device that provides a scattering-based visual effect (such as a color change that occurs in response to transmitted or reflected light).

As discussed elsewhere in this disclosure, performance requirements for the security document 400 may require that in addition to being constructed around the security substrate, a portion of the visual information provided by the security document 400 is provided statically, rather than as part of the optical effect. From a performance perspective, it may be desirable to include static features in the security document to ensure backward compatibility with traditional document handlers, reduce eye strain on duplicate observers (e.g., bank tellers or passport control agents), and facilitate speed and accuracy of automated processing techniques (e.g., by allowing the use of sophisticated trusted processing techniques such as optical character recognition).

Fig. 4C shows an example of incorporating static features (in this case, incorporating window 423 and patch 425) into security document 400, according to various embodiments of the present disclosure. Referring to the non-limiting example of fig. 4C, in some embodiments, the static features are applied by a printed layer 440 applied to the backing side 403 of the security substrate 405. According to embodiments, the static features of the printed layer 440 may be preformed, such as on the surface of a material film applied to the backing side 403 of the security substrate 405. In various embodiments, the static features of print layer 440 may be printed onto the backing side 403 of the security substrate by any suitable printing technique, including but not limited to inkjet printing or flexographic printing. Although in the illustrative example of fig. 4C, print layer 440 is depicted as stopping at the boundary of window 423, embodiments according to the present disclosure are not so limited, and in certain embodiments, features of print layer 440 extend into window 423 and may also be applied to patches 425 disposed in window 423.

As noted elsewhere in this disclosure, the tactile "feel" of the surface of a security document (e.g., a banknote) can be both an indicia of authenticity (e.g., where printing techniques leave an ink pattern over the non-ink surface of the document) and a factor that facilitates the use of a banknote that is configured around a security substrate (e.g., a long-term user may prefer that they feel the same as an older, more familiar version of the document).

Fig. 4D illustrates an example of a security document 400 providing the tactile features described above according to various embodiments of the present disclosure. According to various embodiments, the features of the tactile layer 445 may be formed on the viewing side 401 of the security substrate 405 by printing a material (e.g., a photocurable polymeric ink) onto portions of the viewing side 401 of the security substrate 405. According to certain embodiments, the features of the tactile layer 445 may also provide static features of the banknote (e.g., serial number or graphic design). Depending on the design parameters and as an additional feature to discourage counterfeiters, the static features of the security document 400 may be provided both in the printed layer 440 and through the tactile layer 445. Additionally, in certain embodiments according to the present disclosure, static features disposed in the tactile layer 445 may be applied in registration with other features of the security document 400, including but not limited to optical effects provided by the security substrate 405, the window 423, the patch 425, or features disposed in the printed layer 440.

In some cases, the usage pattern of a particular security document (e.g., banknotes that are in large circulation or storage by users resulting in one or more of rapid wear or limited scrap and replacement) facilitates the application of additional surface protection layers to isolate the micro-optical structures of the security substrate (e.g., focusing element layer 409) from contacts that can accelerate wear of the security substrate 405, and to fill voids or pits in the surface of the security substrate 405 in which dust, oil, or other substances can be present that can reduce the ability of the security substrate 405 to provide authentication optical effects. Fig. 4E shows an example of a security document 400 incorporating such an additional surface protection layer, according to various embodiments of the present disclosure.

Referring to the non-limiting example of fig. 4E, the security substrate 405 includes a sealing layer 450 applied to the viewing side 401 of the security substrate 405. According to various embodiments, the sealing layer 450 comprises a substantially transparent layer of material that conforms to the non-planar portion of the viewing side 401 of the security substrate 405 and provides a substantially planar outer surface of the security document 400.

As noted elsewhere in this disclosure, the use of a security substrate to construct a security document, according to some embodiments of the present disclosure, allows for a wide range of embodiments including the combination and reconfiguration of construction features. Fig. 4F illustrates a non-limiting example of a manner in which the construction features of a security document according to various embodiments of the present disclosure may be mixed and matched.

Referring to the non-limiting example of fig. 4F, the security document 400 includes a sealing layer 450 applied to the viewing side 401 of the security substrate 405. According to various embodiments, the features of the tactile layer 455 may be formed by applying a material (e.g., by printing) directly onto the surface of the sealing layer 450. Although not shown in fig. 4F, in some embodiments, features (e.g., features of the tactile layer 445) are printed onto the viewing side 401 of the security substrate 405 prior to adding the sealing layer 450, and then the features of the tactile layer 455 are subsequently applied. In some embodiments, the features of the tactile layer 455 are applied in registration with one or more other features of the security document, requiring tighter production control and increasing the technical challenges of counterfeiting.

As described elsewhere herein, the security substrate architecture for creating the security document 400 according to certain embodiments of the present disclosure allows for flexibility in integrally forming certain components of the present disclosure as a single component or layer of material (e.g., in some embodiments, two or more of the mask layer 420, the protective layer 430, or the printed layer 440 may be integrally formed). Fig. 4G shows an example of such structural integration in a security document 400.

Referring to the non-limiting example of fig. 4G, the security document 400 includes a sealing layer 450. In this illustrative example, the features of the tactile layer 460 are formed by varying the thickness of the sealing layer 450 (e.g., by embossing the material of the sealing layer 450). In some embodiments, the features of the tactile layer 460 are registered with features disposed in other layers of the security document, giving the other features the sensation of "printing on. In some embodiments, the features of the tactile layer 460 can be used to provide information to a security document in a non-visual manner (e.g., as braille or other indicia familiar to visually impaired users).

In some embodiments, the protective layer 430 comprises a single layer structure (e.g., a transparent film or protective lacquer). In certain embodiments, mechanically masking the microstructures and potentially fragile components of the security document 400 disposed below the backing side 403 of the security substrate 405 may be performed by a protective layer 430 comprising a multilayer protective structure.

Fig. 4H illustrates an example of a security document 400 utilizing a multilayer protective layer 465, according to various embodiments of the present disclosure. Referring to the illustrative example of fig. 4H, in some embodiments, the multilayer protective layer 465 comprises an element of a security document comprising a second security substrate 467 and a second printed layer 469. As shown in the non-limiting example of fig. 4H, certain structures of the security document 400 may function to provide visual information or support optical effects on not only one side, but both sides of the security document 400. For example, in fig. 4H, a single masking layer 420 controls the passage of light through the security document 400 to the viewing side 401 of the security substrate 405 and to the viewing side 471 of the second security substrate plate 467. Similarly, in some embodiments, the window 423 and the patch 425 operate to provide visual information or optical effects that are visible through the regions of the security substrate 405 and the second security substrate 467 that exhibit overall transparency.

According to various embodiments, the security document 400 also includes one or more machine-readable security features that may be detected using specialized equipment, such as a Bill Equipment Manufacturer (BEM) device, including but not limited to Radio Frequency Identification (RFID) antennas, magnetically readable strips, or other devices known in the art as "level 3" features.

As noted elsewhere, examples described with reference to fig. 4A-4H of the present disclosure, including, for example, different configurations of micro-optical structures within the security substrate 405 and different combinations and integrations of components described in the illustrative examples of fig. 4A-4H, are illustrative, and not limiting of embodiments according to the present disclosure.

Fig. 5 illustrates an example of a security document 500 constructed around a pair of security substrates according to various embodiments of the present disclosure.

As discussed with respect to the security document 400 in fig. 4H of the present disclosure, in certain embodiments, the second security substrate may be a protective layer for the first security substrate. In the non-limiting example of fig. 5, an additional illustration of such a security document 500 is provided, wherein a pair of security substrates act as protective layers for each other. According to certain embodiments, the security document 500 comprises a first security substrate 520a (e.g. the security substrate 300 in fig. 3) and a second security substrate 520b (e.g. the second example of the security substrate 300 in fig. 3). In some embodiments according to the present disclosure, the micro-optical structures in the first security substrate 520a project the synthetic image to a viewpoint proximate to the security document 500. As an example of such a composite image, the rolling wave of the "+" sign shown in the figure may appear to "float" above or below the surface of the first security substrate 520 a. According to some embodiments, the security document 500 includes a patch 512 visible through a portion of the first security substrate 520 exhibiting overall transparency. In various embodiments, the security document 500 further includes features of the tactile layer 514 applied to the viewing side of the first security substrate 520a as intaglio-like printed features.

Examples of security documents according to certain embodiments of the present disclosure include: a security document comprising a security substrate comprising a viewing side and a backing side, and a micro-optical system providing an Optically Variable Effect (OVE) on the viewing side; a protective layer; and a masking layer disposed between the protective layer and the backside of the security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents wherein the protective layer comprises a second security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents in which the mask layer comprises a layer of opacifying material.

Examples of security documents according to certain embodiments of the present disclosure include security documents in which the mask layer comprises a layer of reflective material.

Examples of security documents according to certain embodiments of the present disclosure include security documents wherein the mask layer comprises a window.

Examples of security documents according to certain embodiments of the present disclosure include security documents comprising a patch having an authenticity optical marking, wherein the patch is visible through the window of the mask layer.

Examples of security documents according to certain embodiments of the present disclosure include security documents wherein the authentic optical indicia provided by the patch includes at least one of a watermark, an offset design, a gravure design, or an optical security device.

Examples of security documents according to certain embodiments of the present disclosure include security documents comprising tactile features disposed on the viewing side of the security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents wherein the tactile features comprise material printed on the viewing side of the security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents wherein the tactile features comprise intaglio printing on the viewing side of the security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents, wherein the security substrate comprises a layer of focusing elements, a layer of image icons, and an optical spacer, wherein the layer of focusing elements is disposed on a first side of the optical spacer, and wherein the layer of image icons comprises image icons disposed proximate to a focal point of the focusing elements of the layer of focusing elements.

Examples of security documents according to certain embodiments of the present disclosure include security documents in which the focusing element layer comprises refractive focusing elements.

Examples of security documents according to certain embodiments of the present disclosure include security documents in which the focusing element layer comprises a reflective focusing element.

Examples of security documents according to certain embodiments of the present disclosure include security documents in which the image icon layer is disposed on the second side of the optical spacer.

Examples of security documents according to certain embodiments of the present disclosure include security documents in which the optical spacer is integral with the focusing element layer.

Examples of security documents according to certain embodiments of the present disclosure include security documents in which the image icon layer is integral with the focusing element layer.

Examples of security documents according to certain embodiments of the present disclosure include security documents in which ones of the image icons are provided as relief structures in ones of the focusing elements.

Examples of security documents according to certain embodiments of the present disclosure include security documents comprising a sealing layer disposed on the viewing side of the security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents comprising a sealing layer disposed on the viewing side of the security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents that include tactile features provided as a variation in the thickness of the sealing layer.

Examples of security documents according to certain embodiments of the present disclosure include security documents wherein the optical spacer comprises a transparent polymeric sheet.

Examples of security documents according to certain embodiments of the present disclosure include security documents wherein the transparent polymer comprises at least one of polyethylene terephthalate (PET), biaxially oriented polypropylene, polycarbonate, polyester, polypropylene, or polyvinyl chloride (PVC).

Examples of security documents according to certain embodiments of the present disclosure include security documents wherein the OVE includes moire magnification effects.

Examples of security documents according to certain embodiments of the present disclosure include security documents wherein the security substrate comprises an area exhibiting overall transparency, wherein the overall transparency allows static features disposed on or below the backside of the security substrate to be visible through the viewing side of the security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents comprising static features printed on the backing side of the security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents comprising static features provided as color changes in the mask layer.

Examples of security documents according to certain embodiments of the present disclosure include security documents in which the mask layer and the protective layer are provided as a single layer of material coupled to the backing side of the security substrate.

Examples of security documents according to certain embodiments of the present disclosure include security documents that include machine-readable security features.

An example security document of a security document according to certain embodiments of the present disclosure, the security document comprising tactile features, wherein the tactile features are in registration with one or more of a window in the mask layer, a patch, a feature of the printed layer, or the OVE.

While the present disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure, as defined by the following claims.