Fully Micro-Optical Security Document

Abstract

To provide a complete micro-optical security document.SOLUTION: A security document 200 includes a secure substrate 205. The secure substrate 205 includes: a visible side 209; a back side 211; and a micro-optical system that provides an optically variable effect (OVE) on a visible side 209. The security document 200 further includes: a protective layer 225; and a mask layer 215 disposed between the protective layer 225 of the secure substrate 205 and the back side.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure generally relates to security documents (e.g., banknotes) that provide significantly enhanced resistance to the incorporation of security mechanisms (e.g., micro-optical mechanisms) that are difficult to replicate for the production of counterfeit banknotes.

Summary of the Invention

[0002] The present disclosure provides a complete micro-optical security document.

[0003] In a first embodiment, the security document includes a secure substrate having a viewing side and a back side, and the micro-optical system provides an optically variable effect (OVE) on the viewing side. The security document also includes a protective layer and a mask layer disposed between the protective layer of the secure substrate and the back side.

[0004] Other technical features may become apparent to those skilled in the art from the following drawings, description, and claims.

[0005] Definitions for other specific words and phrases are provided throughout this patent specification. Those skilled in the art should understand that, although not many, in many instances such definitions apply to subsequent uses in conjunction with the previous use of such defined words and phrases.

[0006] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0007]

Figure 1

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Mode for Carrying Out the Invention

[0008] Before proceeding to the embodiments for carrying out the following invention, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent specification. The term "couple" and its derivatives refer to any direct or indirect communication or interaction between elements, whether or not those elements are in physical contact with each other. The terms "transmit", "receive", and "communicate", along with their derivatives, encompass both direct and indirect communication. The terms "include" and "comprise", along with their derivatives, mean inclusion without limitation. The term "or" is inclusive and means "and / or". The phrase "associated with", along with its derivatives, means include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or have a relationship or with, etc. 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 in a combination of hardware and software and / or firmware.The functionality associated with any particular controller may be centralized or distributed, regardless of whether it is local or remote. 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 may be used and 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 A, B, C, A and B, A and C, B and C, and A and B and C.

[0009] Definitions for other particular terms and phrases are provided throughout this patent specification. One of ordinary skill in the art should understand that, although not many, in many instances such definitions apply to both prior and subsequent uses of such defined words and phrases.

[0010] The FIGS. 1-5 discussed below and in various embodiments used to explain the principles of the present disclosure in this patent specification are for illustrative purposes only and should not be construed as limiting the scope of the disclosure in any way. One of ordinary skill in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged payment device.

[0011] By presenting the background art and at least one technical problem addressed by a particular embodiment in accordance with the present disclosure, FIG. 1 shows, thereby, an example 100 of a mechanism that can incorporate the security mechanism of one genuine security document 105 (a banknote in this example) and can be used to manufacture two counterfeit security documents of serviceable quality for malicious persons.

[0012] Referring to the embodiment of FIG. 1, an embodiment of a security document 105 is provided. As shown in the figure, the security document 105 includes a substrate 107 incorporating a plurality of structural mechanisms, the plurality of structural mechanisms providing a genuine visible mark and an invisible mark of the security document 105. Examples of structural mechanisms providing an invisible mark of the document include, without limitation, magnetic ink or a machine-readable mechanism (e.g., radio frequency identification (“RFID”)) antenna attached to or embedded in the substrate 107.

[0013] Examples of structural mechanisms with a genuine visible mark include watermarks, printing effects, special inks, and security elements formed within, applied to, or embedded in substrate 107. In this exemplary embodiment, the structural mechanism of security document 105 with a genuine visible mark includes watermark 109, which in some embodiments is formed through the use of a dandy roll patterned during the manufacture of the paper of substrate 107. A further example of the structural mechanism of security document 105 with a genuine visual mark includes intaglio pattern 111, which, due to the high-definition resolution of the pattern and the use of intaglio printing technology, includes a pattern of lines that is difficult to reproduce and produces a characteristic moiré interference effect with a unique surface texture. In this exemplary embodiment, the structural mechanism of security document 105 with a genuine visual mark of the document includes an area 113 printed with a special, hard-to-obtain ink, such as an optically variable ink or a color shift ink, whose appearance changes in response to a change in the angle of incidence of light striking the ink. The structural mechanism with a genuine visible mark of security document 105 can also include security element 115. In some embodiments, security element 115 includes a microscale or nanoscale optical structure, for example, a thin material (such as a narrow ribbon of a polymer substrate) that supports one or more arrays of lenses, icon structures, or diffraction gratings that collectively produce a unique optical effect. Examples of such optical effects include, without limitation, moiré magnification effects (sometimes referred to as "synthetically enlarged images" or "synthetic images"), integral imaging effects, color shifts, or optically variable effects such as holograms.

[0014] With improvements in imaging and printing technologies, criminal ingenuity has provided malicious actors with the ability and materials to create counterfeit security documents constructed around paper substrates that provide many serviceable reproductions of the described structural mechanisms for providing a true visible mark of the security document provided on substrate 107. Assuming the very small scale of the optical structures within security element 115 and the organizational control over the specific tools, materials, and techniques involved in the manufacture of security element 115, most malicious actors currently do not have the means or technical know-how to replicate security element 115.

[0015] As a fallback when it is not possible to reproduce security element 115, malicious actors seeking to create counterfeit security documents "capture" the security element from a genuine document for the purpose of incorporating parts of the captured security element into one or more counterfeit security documents. Referring to the illustrative embodiment of FIG. 1, security element 115 is a micro-optical thread spanning the width of security document 100. As shown in the figure, security element 115 is embedded in substrate 107 such that portions of security element 115 are visible through window 117 in the substrate and other portions of the security element are concealed by bridge 119.

[0016] Referring to the illustrative embodiment of FIG. 1, in certain cases, malicious actors can remove security element 115 substantially intact by soaking security document 100 in a solvent (e.g., water or bleach) for an extended period of time such that the adhesive between security element 115 and substrate 107 is removed or substrate 107 is destroyed. Once removed substantially intact, security element 115 is carefully cut into pieces (130), and the pieces, while not a perfect replica of security document 105, can be easily circulated among many users as a genuine document and mistaken for the real thing. Carrier threads are attached to the surfaces of a plurality of counterfeit substrates 140a and 140b, or alternatively to the surfaces of carrier threads embedded in the surfaces of a majority of counterfeit documents that carry minute visual markings, so as to be manufactured from an initial number of genuine security documents.

[0017] Although not discussed in the illustrative embodiment of FIG. 1, other methods of manufacturing counterfeit security documents may be enabled by incorporating the security element 115 substantially intact. For example, when incorporated, the security element 115 may be upcycled to manufacture counterfeit banknotes that are more valuable than the security document 105. Alternatively, in cases where the security document is an identification document or otherwise associated with an authorized person, incorporating the security element 115 substantially intact may facilitate the manufacture of counterfeit security documents associated with unauthorized persons (e.g., for manufacturing counterfeit passports).

[0018] As shown by the illustrative embodiment of FIG. 1, the valid hypotheses behind incorporation include, at a minimum, the hypothesis that the optical security element is separable from the substrate and the hypothesis that the structural mechanism of the substrate providing the genuine visual markings of the security document can be reproduced in a state usable by malicious persons. As discussed herein, certain embodiments in accordance with the present disclosure cover those valid hypotheses by providing a security document structured around a secure substrate that includes a region of material exhibiting suitable flexibility and tensile strength for application while at the same time presenting difficulties in reproducing optical effects such as optical variable effects. In so doing, certain embodiments in accordance with the present disclosure provide technical and practical advantages that deny malicious persons the opportunity to manufacture counterfeit documents by applying components incorporated into criminally usable quality counterfeit substrates from genuine documents.

[0019] Figure 2 shows, in an exploded view, the elements of a security document 200 incorporating a secure substrate, according to various embodiments of the present disclosure. Figure 2 shows a banknote as an example of a security document according to various embodiments of the present disclosure, but embodiments according to the present disclosure are not so limited. Examples of security documents according to the present disclosure include, without limitation, identification documents (e.g., driver's licenses), authentication labels on products counterfeiting targets (e.g., handbags or watches), or financial documents (e.g., money orders or other negotiable instruments). In this exemplary embodiment, the components numbered 205, 215, 225, 235, 245, and 255 in the figure control the appearance aspect of the security document 200 when viewed from above (in Figure 2, the surface element 255).

[0020] Referring to the non-limiting embodiment of Figure 2, the security document 200 includes a secure substrate 205 (e.g., the secure substrate 300 in Figure 3), which is appropriately flexible, durable, and strong to serve as a structural anchor for the security document 200 while providing an optical effect based on authentication microstructures. According to certain embodiments, the secure substrate 205 includes a sheet of material including microstructures that produce an optical effect that serves as a genuine visual mark of the security document 200. In some embodiments, the microstructures produce optically variable effects (OVE) such as the moiré magnification effect of icon microstructures (sometimes also referred to as "synthetic images" or "synthetically enlarged images"), a motion effect (where the synthetic image appears to "move" or change appearance in response to a change in the viewing angle), or a color shift effect. As shown in the exemplary embodiment of Figure 2, in certain embodiments, the microstructures that produce the optical effect include microscale focusing elements (e.g., the focusing element 207). Depending on the embodiment, the focusing element 207 is a refractive focusing element (e.g., flat A microlens having a convex outer shape, a concave outer shape, or a flat outer shape (such as a gradient index (GRIN) lens). In some embodiments, the focusing element 207 is a reflective focusing element (e.g., a microscale concave mirror). In some embodiments, the microstructure on the secure substrate 205 is a diffractive microstructure that produces diffractive-based effects (e.g., color effects caused by diffraction gratings within the secure substrate 205).

[0021] In some embodiments, the secure substrate 205 includes a viewing side 209 (visible in FIG. 2) and a back side 211 that is opposite the viewing side 209 (invisible in FIG. 2).

[0022] As shown in the exemplary embodiment of FIG. 2, the security document 200 includes a mask layer 215 disposed between the protective layer 225 of the secure substrate 205 and the back side 211. According to various embodiments, the mask layer 215 includes a sheet of material or an applied coating that blocks some or all views of the printed layer 235, the secure substrate 205, and the tactile layer 255 from a viewing point facing the lower surface 227 of the protective layer 225. In certain embodiments, the mask layer 215 includes a layer of an opaque material, such as a coating or an opaque film having a color selected to enhance the visibility of the optical effects produced by the secure substrate 205. In some embodiments, the mask layer 215 has a color selected for contrast with other mechanisms (e.g., the colors used within the printed layer 235). In embodiments where the secure substrate 205 produces a moiré magnification effect, a light color (e.g., white) may be particularly suitable for the opaque mask layer 215. In certain embodiments, the mask layer 215 includes a layer of a reflective material, such as a metal coating or an applied foil.

[0023] In certain embodiments, the mask layer 215 includes a window 217, through which light incident on the security document 200 through the lower surface 227 of the protective layer 225 can pass through the secure substrate 205. In various embodiments, the patch 245 is provided within the window 217. According to various embodiments, the patch 245 includes a region of material (e.g., a fibrous material such as banknote paper, a polymer material, or a metallic material), the region of material providing a further authentic optical mark of the security document 200 and being visible from one or both sides of the security document 200. As shown in the exemplary embodiment of FIG. 2, the further authentic optical mark provided by the patch 245 is, in some embodiments, a watermark 247. In some embodiments, the further authentic optical mark provided by the patch 245 is a printed pattern (e.g., an offset or intaglio printed pattern) or another optical security element (e.g., a hologram). In this way, the window 217 and the patch 245 facilitate the incorporation of a widely recognized security mechanism into a security document according to the present disclosure, structured around the secure substrate 205, from a legacy security document where the optical security element was a separate component from the substrate. As a practical example, a user who has authenticated banknotes for decades by checking for the presence of accurately formed watermarks can similarly authenticate the security document 200.

[0024] In particular, in some applications where compatibility with legacy document processors (e.g., currency readers in vending machines) or adaptation by users familiar with older security documents is not a gating issue, it may be advantageous to structure the security document 200 such that all of the visual information of the document is provided as optical effects. However, in some applications, it may be appropriate for a portion of the visual information provided by the security document 200 to be provided as a static (not changing in appearance with respect to viewing angle or lighting conditions) mechanism. Examples of visual information that may advantageously be provided as a static mechanism include, without limitation, printing mechanisms carried over from legacy security mechanisms (for promoting backward compatibility with existing document processing systems), and alphanumeric text providing essential information such as face value, address, or serial number (for promoting machine readability of this information and reducing eye fatigue for human readers).

[0025] Referring to the non-limiting example of FIG. 2, the secure substrate 205 includes one or more regions exhibiting overall transparency. As used in the present disclosure, the term "overall transparency" encompasses the characteristics of static mechanisms provided on or below the back side 211 of the secure substrate to be visible through the viewing side 209 at a macro level (i.e., in a state at a scale visible to the human eye). In certain embodiments according to the present disclosure, for example, in certain embodiments where the secure substrate 205 uses a layer of refractive focusing elements to produce a moiré magnification effect of micro-scale iconographic mechanisms within an icon layer, the very small scale icons and lens mechanisms render the entirety of the secure substrate 205 substantially transparent.

[0026] According to some embodiments, a static mechanism that can be viewed through a substantially transparent region of the secure substrate 205 is provided within a printed layer 235 applied to the back side 211 of the secure substrate 205. In some embodiments according to the present disclosure, the static mechanism (e.g., geometric shape pattern 237 and flag 239) is printed using one or more printing techniques suitable for manufacturing security documents, including, without limitation, offset printing, flexographic printing, intaglio, gravure, or inkjet printing. In some embodiments, the mechanism of the printed layer 235 is applied such that it is recorded by one or more of the optical effects provided by the secure substrate 205, the window 217, the patch 245, or the tactile layer 255. In some embodiments, the printed layer 235 is applied to the back side of the secure substrate 205 and the mask layer 215 is then applied. In some embodiments, the printed layer 235 and the mask layer 215 comprise a single integrated layer.

[0027] Referring to the non-limiting embodiments of FIG. 2, in some embodiments, the security document 200 includes a haptic layer 255 that is applied to the viewing side 209 of the secure substrate 205 and includes a mechanism that can be touched by a user handling the security document 200. According to some embodiments, the haptic layer 255 includes a transparent sealing layer that covers the viewing side 209 of the secure substrate 205. For example, in some embodiments, such as embodiments where the viewing side 209 of the secure substrate 205 has a surface that is not substantially flat (e.g., a concave-convex surface by a plano-convex microlens), the sealing layer may accumulate contaminants and may reduce the ability of the secure substrate 205 to provide an optical effect. By filling the gaps between the lenses, the overall performance of the security document can be improved. In some embodiments where the haptic layer 255 includes a transparent sealing layer, the haptic mechanism (e.g., text 257 and currency unit 259) may be provided by printing a material on the surface of the sealing layer (e.g., using intaglio printing that produces a characteristic surface texture). In various embodiments where the haptic layer 255 includes a transparent sealing layer, the haptic mechanism may be provided by causing variations in the thickness of the sealing layer (e.g., by embossing). In certain embodiments where the haptic layer 255 does not include a transparent sealing layer, the haptic mechanism is generated by directly printing a material on the viewing side 209 of the secure substrate 205. According to various embodiments, the haptic mechanism of the haptic layer 255 (e.g., mechanisms 257 and 259) is formed to be recorded by one or more of the optical effects provided by the secure substrate 205, the mechanisms of the printing layer 235, the window 217, or the patch 245.

[0028] As shown in the exemplary embodiment of FIG. 2, the security document 200 includes a protective layer 225. According to various embodiments, the protective layer 225 includes a single-layer or multi-layer structure that protects the thin (e.g., reflective foil used as the mask layer 215) or delicate (e.g., patch 245) structure of the security document from wear and exposure to destructive contaminants. In some embodiments, the protective layer 225 includes a sheet of material (e.g., a fibrous material such as a thin polymer film or paper) adhered to the mask layer 215. In accordance with the present disclosure In various embodiments, the protective layer 225 includes a coating of a suitably durable material (e.g., a photocurable resin suitable for forming 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 includes a multi-layer structure structured around a second secure substrate (e.g., as shown in FIGS. 4H and 5 of the present disclosure).

[0029] FIG. 3 shows the structural aspects of an exemplary embodiment of a secure substrate 300 in accordance with various embodiments of the present disclosure. For reference, FIG. 3 is oriented such that the viewing side 301 of the secure substrate appears near the top of the figure and the back surface 303 appears at the bottom of the figure.

[0030] Referring to the non-limiting embodiment of FIG. 3, in certain embodiments, the secure substrate 300 includes a plurality of focusing elements 305 (e.g., including focusing element 307), and an array 321 of image icons (e.g., including image icon 320). According to various embodiments, each focusing element of the plurality of focusing elements 305 has a footprint, and in the footprint, one or more image icons of the array 321 of image icons are positioned proximate to the focus of the focusing element such that at a particular viewing angle, the focusing element focuses on the image icon. Collectively, the focusing elements of the plurality of elements 305 enlarge a portion of the array 321 of image icons to produce a moiré magnification effect (also referred to as a “synthetically enlarged image” or more simply, a “synthetic image”), and the individual microscopic image icons are collectively enlarged by the plurality of focusing elements 305 to produce an image that dynamically responds (e.g., appears to move or appears to change color) in response to a shift in the viewing angle. In some embodiments, in conjunction with the moiré magnification effect described above, the plurality of focusing elements 305 may operate with the array 321 of image icons to generate an integrated image. As used in this disclosure, the term “integrated image” encompasses the visual effect produced by a micro-optical system based on processing a set of viewpoint images to generate an image layer used to define the configuration, or a portion thereof, of the array 321 of image icons. International Publication No. WO2013 / 163287, entitled “Security Device For Projecting a Collection of Synthetic Images”, provides non-limiting examples of integrated images according to certain embodiments of the present disclosure. Although difficult for many malicious actors to reproduce, if not impossible, the moiré magnification effect described above is, in many cases, a true and reliable visual mark of a security document structured around the secure substrate 300.

[0031] According to certain embodiments, the plurality of focusing elements 305 includes a planar array of micro-optical focusing elements. In some embodiments, the focusing elements of the plurality of focusing elements 305 include micro-optical refractive focusing elements (e.g., plano-convex or GRIN lenses). The refractive focusing elements of the plurality of focusing elements 305 are, in some embodiments, generated from a photocured resin having a refractive index ranging from 1.35 to 1.7 and having a diameter ranging from 5 micrometers to 200 micrometers. In various embodiments, the focusing elements of the plurality of focusing elements 305 include reflective focusing elements (e.g., very small concave mirrors) having a diameter ranging from 5 micrometers to 50 micrometers. In this exemplary embodiment, the focusing elements of the plurality of focusing elements 305 are shown as including annular plano-convex lenses, although other refractive lens geometries, such as lenticular lenses, are possible and within the scope contemplated by the present disclosure.

[0032] As shown in the exemplary embodiment of FIG. 3, the array of image icons 320 includes a set of image icons (including image icon 321) positioned at a predetermined location proximate the focal point of the focusing elements of the plurality of focusing elements 305. According to various embodiments, individual image icons of the array of image icons 320 include regions of photocured material associated with the focal path of structured light (e.g., collimated UV light), the light passing through the plurality of focusing elements 305 from a projection point associated with one or more predetermined ranges of viewing angles passes through. In some embodiments, individual image icons of the array of image icons 320 are provided within a structured image icon layer that includes a structure for maintaining a large amount of pigmented material. In some embodiments, individual image icons of the array of image icons 320 are not provided within a 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 maintaining image icon material. According to various embodiments, individual image icons of the array 321 of image icons are provided within a structured image layer that functions to maintain a structure for holding colorant materials of microscale and nanoscale volumes, and includes one or more of cavities, mesas, or posts. In some embodiments, the image icons of the image icon layer 321 are formed by directing the curing of a photocurable material through a plurality of focusing elements 305 to control the viewing angle at which the focus of the focusing element is positioned over the image icon and, by extension, the viewing angle at which a particular optical effect is visible.

[0033] As shown in the exemplary embodiment of FIG. 3, in certain embodiments, the secure substrate 300 includes an optical spacer 310. According to various embodiments, the optical spacer 310 includes a film of substantially transparent material that operates to position the image icons of the array of image icons 320 within or around the focal plane of the focusing elements of the plurality of focusing elements 305. In certain embodiments according to this disclosure, the optical spacer 310 includes a manufacturing substrate on which one or more layers of curable material can be applied to form one or more of the array of image icons 320 or the plurality of focusing elements 305. In certain embodiments according to this disclosure, the optical spacer 310 does not include a structure separate from the plurality of focusing elements 305, but rather is formed integrally with the plurality of focusing elements 305 (e.g., by molding).

[0034] In accordance with various embodiments, the secure substrate 300 includes one or more regions of a light-cured protective material 330 that occupy the space between the image icons of the array of image icons 320. In some embodiments, the array of image icons 320 is first formed (e.g., by selectively curing and removing a liquid light-curable material on the optical spacer 310), and then a layer of a transparent, light-curable material is applied to fill the space between the image icons of the array of image icons 320, and then flood cured to produce a protective layer that protects the image icons from moving from their positions within the footprints of the focusing elements of the plurality of focusing elements 305. In certain embodiments, the light-curable material used to form the array of image icons 320 is a pigmented, ultraviolet (UV)-curable polymer.

[0035] In certain embodiments in accordance with the present disclosure, the secure substrate 300 includes a sealing layer 340 on the viewing side 301 of the secure substrate 300. In accordance with certain embodiments, the sealing layer 340 includes a thin portion of a substantially transparent material (e.g., a layer having a thickness of 2 micrometers to 50 micrometers) that joins on the lower surface having the focusing elements of the plurality of focusing elements 305, and an upper surface that varies less in curvature than the plurality of focusing elements 305 (e.g., by being flat or having a surface with local undulations that are undulations of a radius of curvature greater than that of the focusing elements).

[0036] FIG. 3 provides one example of a secure substrate 300 in accordance with various embodiments, but the present disclosure is not so limited. For example, in FIG. 3, the array of image icons 321 is shown as being structurally distinct from the plurality of focusing elements 305, but in some embodiments, the focusing elements and the image icons can be provided in a single layer. For example, in some embodiments, the image icons can be provided as selectively positioned relief structures or “dimples” on the surface of an array of convex lenses (sometimes referred to as “Gregison” lenses). As a further example, embodiments incorporating reflective focusing elements In one state, the image icon may be provided as a color region within a "layer" between the reflective surfaces of the focusing element. In such an embodiment, the image icon and the focusing element may be provided on a single side of the optical spacer, in contrast to the embodiment of FIG. 3, and the image icon 320 and the focusing element 307 occupy different sides of the optical spacer 310.

[0037] Figures 4A - 4H show examples of security documents structured using secure substrates according to various embodiments of the present disclosure. The examples discussed with reference to Figures 4A - 4H are illustrative of a wide range of potential configurations of security documents structured around one or more secure substrates according to embodiments of the present disclosure. Additional embodiments and configurations beyond those described with reference to Figures 4A - 4H are within the contemplated scope of the present disclosure. For convenience, structural elements common to more than one figure are numbered alike.

[0038] Referring to the non - limiting example of FIG. 4A, a security document 400 according to various embodiments of the present disclosure is shown in the figure. In some embodiments according to the present disclosure, the security document 400 includes a viewing side 401 and a back side 403, a protective layer 430, and a secure substrate 405 (e.g., the secure substrate 300 in FIG. 3) having a mask layer 420 disposed between the back side 403 of the secure substrate 405 and the protective layer 430. According to certain embodiments, the secure substrate 405 includes micro - scale optical structures that produce an optical effect on the viewing side, which is the true optical mark of the security document 400.

[0039] According to certain embodiments, the secure substrate 405 provides an optical variable effect, such as a moiré magnification effect, through a pattern at the incidence of the focus of the focusing element (e.g., focusing element 407) of the focusing element layer 409 on the image icon (e.g., image icon 411) of the image icon layer 413. In some embodiments, the secure substrate 405 includes an optical spacer 415. As shown in the exemplary embodiment of FIG. 4A, the optical spacer 415 includes a carrier film having a first side and a second side. According to some embodiments, the focusing element layer 409 is provided on the first side of the optical spacer 415, and the image icon layer 413 is provided on the second side of the optical spacer 415. In some embodiments, both the focusing element layer 409 and the image icon layer are provided on the same side of the optical spacer 415. In various embodiments, one or more of the optical spacer 415, the focusing element layer 409, and the image icon layer 413 are integral with each other by being repeatedly structured within a layer of a common material (e.g., a photocurable polymer).

[0040] In the exemplary embodiment of FIG. 4A, security document 400 has been discussed with respect to embodiments in which the secure substrate 405 includes an optical microstructure that provides an optical variable effect (e.g., a moiré magnification effect), but other embodiments that include a secure substrate that produces different optical effects (e.g., interference-based effects or diffraction effects) are within the scope contemplated by the present disclosure, which covers embodiments of security documents where the structural backbone of the security document is a substrate from which components that include microstructures that produce optical effects can be separated.

[0041] 4A, the mask layer 420 comprises a thin layer of material (e.g., a painted layer, a coating, or a thin film of a reflective or opaque material) that limits the visibility of structures disposed between the mask layer and the viewing side 401 of the secure substrate from the underside of the security document. According to various documents, the security document 400 further comprises a protective layer 430 that, depending on the embodiment, protects the secure substrate 405 from contact with objects or solvents that may damage or degrade the microstructures of the secure substrate 405 (e.g., the pictorial icons 411) or other security features and visual information of the security document 400 (e.g., a watermark painted in a window of the mask layer 430). There may be one or more layers of material that operate to shield structures between the mask layer 420 and the viewing side 401 of the substrate. In some embodiments, the protective layer 430 comprises a sheet of polymer (e.g., biaxially oriented polypropylene) or fibrous (e.g., banknote paper) material.

[0042] As noted elsewhere in this disclosure, structuring the security document around the secure substrate 405 allows for a wide range of permutations of structures and features that can be incorporated into the security document, as well as providing a structural underpinning to the security document while also providing signature optical effects that are difficult for most, if not all, malicious actors to replicate through the microstructure of the secure substrate itself. Figure 4B shows examples of additional features (in this case, windows and patches) that can be incorporated into the security document, in accordance with various embodiments of the present disclosure.

[0043] Referring to the non-limiting embodiment of FIG. 4B, in some embodiments, window 423 is provided within mask layer 420. In certain embodiments according to the present disclosure (e.g., embodiments where mask layer 420 is a coated film), window 423 is formed by not applying the coating to the back side 403 of secure substrate 405. In some embodiments, window 423 is pre-formed (e.g., as a hole in a reflective or opaque film applied to the back side 403 of secure substrate 405). According to certain embodiments, window 423 is formed such that it is recorded by region 427 of secure substrate 405 that exhibits a total transparency, which enables a static mechanism on a scale visible to the naked eye to be visible through viewing side 401 of secure substrate 405. Depending on the structure of security document 400, window 423 may be, alone, a mechanism of security document 400. As an exemplary embodiment, in embodiments where protective layer 430 is transparent, window 423 allows light to pass through the entirety of security document 400, which can be a very specific mechanism of certain security documents, such as banknotes, which are often opaque over their entire surface area.

[0044] In some embodiments, window 423 operates to facilitate the inclusion of patch 425 of material with a genuine additional optical mark. According to certain embodiments, the genuine optical mark provided by patch 425 is at least one of additional optical security elements such as a watermark, a dyed pattern (e.g., a pattern printed using offset or intaglio printing), or a hologram, or a scattering-based visual effect (such as a change in color in response to transmitted or reflected light).

[0045] As discussed elsewhere in this disclosure, the performance requirements for the security document 400 may require that, in addition to being structured around the secure substrate, a portion of the visual information provided by the security document 400, rather than being part of the optical effect, is provided statically. From a performance perspective, including static mechanisms in the security document can ensure backward compatibility with legacy documents handled by machines, reduce eye fatigue for repeat viewers (e.g., bank tellers or immigration officers), and may be desirable for facilitating the speed and accuracy of automated processing technologies (e.g., by enabling the use of mature and reliable processing technologies such as optical character recognition).

[0046] FIG. 4C shows an example incorporating a static mechanism, in this case, with window 423 and patch 425 within security document 400, in accordance with various embodiments of the present disclosure. Referring to the non-limiting example of FIG. 4C, in some embodiments, the static mechanism is applied through a printed layer 440 applied to the back side 403 of the secure substrate 405. Depending on the embodiment, the static mechanism of the printed layer 440 may be pre-formed, such as on the surface of a film of the material applied to the back side 403 of the secure substrate 405. In various embodiments, the static mechanism of the printed layer 440 may be printed on the back side 403 of the secure substrate by any suitable printing technology, including, without limitation, inkjet printing or flexographic printing. In the exemplary embodiment of FIG. 4C, the printed layer 440 is shown as ending at the boundary of the window 423, but embodiments in accordance with the present disclosure are not so limited, and in certain embodiments, the mechanism of the printed layer 440 may extend into the window 423 and may be applied to a patch 425 provided within the window 423.

[0047] As otherwise described herein, the tactile "feel" of the surface of a security document (e.g., a banknote) can be both a genuine mark (e.g., a printing technique that leaves a pattern of ink on a surface of the document where no ink was previously applied) and a factor that facilitates the adaptation of the banknote structured around the secure substrate (e.g., a long-term user can evaluate how similarly they feel to older, more sophisticated versions of the document).

[0048] Figure 4D shows an example of a security document 400 according to various embodiments of the present disclosure provided with the tactile mechanism described above. According to various embodiments, the mechanism of the tactile layer 445 can be formed on the viewing side 401 of the secure substrate 405 by printing a material (e.g., a photo-curable polymer ink) on a portion of the viewing side 401 of the secure substrate 405. According to certain embodiments, the mechanism of the tactile layer 445 can also provide a static mechanism (e.g., a serial number or a graphic pattern) of the banknote. Depending on the pattern parameters and as an additional mechanism to deter counterfeiters, the static mechanism of the security document 400 may be provided both within the printing layer 440 and through the tactile layer 445. Additionally, in certain embodiments according to the present disclosure, the static mechanism provided within the tactile layer 445 can be applied to be recorded by other mechanisms of the security document 400, including, without limitation, optical effects provided by mechanisms provided within the secure substrate 405, the window 423, the patch 425, or the printing layer 440.

[0049] In some cases, the usage patterns of certain security documents (e.g., banknotes that are circulated or stored extensively by users, leading to one or more of rapid wear or restricted disposal and replacement) may cause contact that accelerates the wear of the secure substrate 405, separating the micro - optical structure (e.g., layer 409 of focusing elements) of the secure substrate from contact, and there may be dust, oil, or other substances that degrade the ability of the secure substrate 405 to provide an authenticable optical effect. This favors the application of an additional layer of surface protection to fill voids or depressions within the surface of the secure substrate 405. FIG. 4E shows an example of a secure document 400 according to various embodiments of the present disclosure incorporating such an additional layer of surface protection.

[0050] Referring to the non - limiting example of FIG. 4E, the secure substrate 405 includes a sealing layer 450 applied to the viewing side 401 of the secure substrate 405. According to various embodiments, the sealing layer 450 includes a substantially transparent layer of material that conforms to the non - flat portions of the viewing side 401 of the secure substrate 405, resulting in a substantially flat outer surface of the security document 400.

[0051] As otherwise described in the present disclosure, the use of a secure substrate for constructing a security document according to some embodiments of the present disclosure allows a wide range of embodiments to include combinations and reconfigurations of structural mechanisms. FIG. 4F shows a non - limiting example of how the structural mechanisms of a security document according to various embodiments of the present disclosure can be mixed and matched.

[0052] 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 secure substrate 405. According to various embodiments, the mechanism of the tactile layer 455 is by directly applying material on the surface of the sealing layer 450 (e.g., Alternatively, it can be formed by printing. Although not shown in FIG. 4F, in some embodiments, before the addition of the sealing layer 450, a mechanism (e.g., the mechanism of the haptic layer 445) is printed on the viewing side 401 of the secure substrate 405, and then the mechanism of the haptic layer 455 is subsequently applied. In some embodiments, the mechanism of the haptic layer 455 is applied to be recorded by one or more other mechanisms of the security document, which requires more stringent manufacturing control and increases the technical challenges of counterfeiting.

[0053] As otherwise described in this disclosure, the secure substrate architecture used to create a security document 400 according to certain embodiments of this disclosure allows for flexibility in integrating certain components of this 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 printing layer 440 can be integrally formed). FIG. 4G shows an example of such a structural integration within the security document 400.

[0054] Referring to the non-limiting example of FIG. 4G, the security document 400 includes a sealing layer 450. In this exemplary embodiment, the mechanism of the haptic layer 460 is formed by causing a variation in the thickness of the sealing layer 450 (e.g., by embossing the material of the sealing layer 450). In some embodiments, the mechanism of the haptic layer 460 is recorded by a mechanism provided within another layer of the security document, thereby giving a "printed" tactile sensation to the other mechanism. In some embodiments, the mechanism of the haptic layer 460 can be used to provide information of the security document in a non-visual manner (e.g., Braille text, or other marks known to users with visual impairments).

[0055] In some embodiments, the protective layer 430 includes a single-layer structure (e.g., a transparent film or a protective lacquer). In certain embodiments, mechanically shielding the microstructures and potentially delicate components of the security document 400 disposed under the back side 403 of the secure substrate 405 can be performed by a protective layer 430 including a multi-layer protective structure.

[0056] FIG. 4H shows an example of a security document 400 utilizing a multi-layer protective layer 465, according to various embodiments of the present disclosure. Referring to the exemplary embodiment of FIG. 4H, in some embodiments, the multi-layer protective layer 465 includes elements of the security document, including a second secure substrate 467 and a second printed layer 469. As shown in the non-limiting example of FIG. 4H, the particular structure of the security document 400 can function to provide visual information or support optical effects on both sides of the security document 400, not just a single side. For example, in FIG. 4H, a single mask layer 420 controls the passage of light to the security document 400 from the viewing side 401 of the secure substrate 405 to the viewing side 471 of the second secure substrate 467. Similarly, in some embodiments, the windows 423 and patches 425 operate to provide visual information or optical effects that are visible through regions of the secure substrate 405 and the second secure substrate 467 that exhibit overall transparency.

[0057] According to various embodiments, the security document 400 further includes one or more machine-readable security mechanisms including, without limitation, other devices known in the art as "Level 3" mechanisms detectable using special devices such as radio frequency identification (RFID) antennas, magnetic readable strips, or banknote equipment manufacturer (BEM) devices.

[0058] As described elsewhere, the embodiments described with reference to FIGS. 4A-4H of the present disclosure are exemplary and do not limit embodiments in accordance with the present disclosure, including, for example, different configurations of the micro-optical structures within the secure substrate 405 and different combinations and integrations of the components described in the illustrative embodiments of FIGS. 4A-4H.

[0059] FIG. 5 shows an example of a security document 500 structured around a pair of secure substrates in accordance with various embodiments of the present disclosure.

[0060] For example, as discussed with respect to the security document 400 in FIG. 4H of the present disclosure, in certain embodiments, the second secure substrate can be a protective layer for the first secure substrate. In the non-limiting example of FIG. 5, a further example of such a security document 500 is provided where a pair of secure substrates serve as protective layers for each other. In accordance with certain embodiments, the security document 500 includes a first secure substrate 520a (e.g., the secure substrate 300 of FIG. 3), and a second secure substrate 520b (e.g., a second example of the secure substrate 300 of FIG. 3). In some embodiments in accordance with the present disclosure, the micro-optical structure within the first secure substrate 520a projects a synthetic image at a viewing point proximate to the security document 500. As an example of such a synthetic image, the wavy "plus" sign shown in the figure can appear to "float" above or below the surface of the first secure substrate 520a. In accordance with some embodiments, the security document 500 includes a patch 512 that is visible through a portion of the first secure substrate 520 that exhibits a total transparency. In various embodiments, the security document 500 further includes a mechanism of a haptic layer 514 applied to the viewing side of the first secure substrate 520a as an intaglio printing mechanism.

[0061] Examples of security documents according to certain embodiments of the present disclosure include a secure substrate including a viewing side and a back side, a micro-optical system that provides an optically variable effect (OVE) on the viewing side, a protective layer, and a mask layer disposed between the protective layer of the secure substrate and the back side.

[0062] Examples of security documents according to certain embodiments of the present disclosure include a security document in which the protective layer includes a second secure substrate.

[0063] Examples of security documents according to certain embodiments of the present disclosure include a security document in which the mask layer includes a layer of an opaque material.

[0064] Examples of security documents according to certain embodiments of the present disclosure include a security document in which the mask layer includes a layer of a reflective material.

[0065] Examples of security documents according to certain embodiments of the present disclosure include a security document in which the mask layer includes a window.

[0066] Examples of security documents according to certain embodiments of the present disclosure include a security document including a patch including a genuine optical mark, the patch being visible through the window of the mask layer.

[0067] Examples of security documents according to certain embodiments of the present disclosure include a security document in which the genuine optical mark provided by the patch includes at least one of a watermark, an offset print pattern, an intaglio print pattern, or an optical security element.

[0068] Examples of security documents according to certain embodiments of the present disclosure include a security document including a tactile mechanism disposed on the viewing side of the secure substrate.

[0069] Examples of security documents according to certain embodiments of the present disclosure include security documents in which the haptic mechanism includes materials printed on the viewing side of the secure substrate.

[0070] Examples of security documents according to certain embodiments of the present disclosure include security documents in which the haptic mechanism includes intaglio printing on the viewing side of the secure substrate.

[0071] Examples of security documents according to certain embodiments of the present disclosure include security documents in which the secure substrate includes a layer of focusing elements, a layer of image icons, and an optical spacer, the layer of focusing elements being disposed on a first side of the optical spacer, and the layer of image icons including image icons disposed proximate to the foci of the focusing elements of the layer of focusing elements.

[0072] Examples of security documents according to certain embodiments of the present disclosure include security documents in which the layer of focusing elements includes refractive focusing elements.

[0073] Examples of security documents according to certain embodiments of the present disclosure include security documents in which the layer of focusing elements includes reflective focusing elements.

[0074] Examples of security documents according to certain embodiments of the present disclosure include security documents in which the layer of image icons is disposed on a second side of the optical spacer.

[0075] Examples of security documents according to certain embodiments of the present disclosure include security documents in which the optical spacer is integral with the layer of focusing elements.

[0076] Examples of security documents according to certain embodiments of the present disclosure include security documents in which the layer of image icons is integral with the layer of focusing elements.

[0077] An example of a security document according to a particular embodiment of the present disclosure includes a security document in which image icons of an image icon layer are provided as relief structures within focusing elements of a focusing element layer.

[0078] An example of a security document according to a particular embodiment of the present disclosure includes a security document that includes a sealing layer disposed on the viewing side of a secure substrate.

[0079] An example of a security document according to a particular embodiment of the present disclosure includes a security document that includes a sealing layer disposed on the viewing side of a secure substrate.

[0080] An example of a security document according to a particular embodiment of the present disclosure includes a security document that includes a tactile mechanism provided as a variation in the thickness of a sealing layer.

[0081] An example of a security document according to a particular embodiment of the present disclosure includes a security document in which an optical spacer includes a sheet of transparent polymer.

[0082] An example of a security document according to a particular embodiment of the present disclosure includes a security document in which the transparent polymer includes at least one of polyethylene terephthalate (PET), biaxially oriented polypropylene, polycarbonate, polyester, polypropylene, or polyvinyl chloride (PVC).

[0083] An example of a security document according to a particular embodiment of the present disclosure includes a security document in which OVE includes a moiré magnification effect.

[0084] An example of a security document according to a particular embodiment of the present disclosure includes a secure substrate that includes a region exhibiting total transparency, and the total transparency is disposed above or below the back side of the secure substrate. A security document is included that enables a static mechanism provided to be visible through the viewing side of the secure substrate.

[0085] An example of a security document according to a particular embodiment of the present disclosure includes a security document that includes a static mechanism printed on the back side of the secure substrate.

[0086] An example of a security document according to a particular embodiment of the present disclosure includes a security document that includes a static mechanism provided as a variation in color within a mask layer.

[0087] An example of a security document according to a particular embodiment of the present disclosure includes a security document in which a mask layer and a protective layer are provided as a single layer of material bonded to the back side of the secure substrate.

[0088] An example of a security document according to a particular embodiment of the present disclosure includes a security document that includes a machine-readable security mechanism.

[0089] An example of a security document according to a particular embodiment of the present disclosure includes a security document that includes a tactile mechanism, and the tactile mechanism is recorded by one or more of a window, a patch, a mechanism of a printed layer, or an OVE within the mask layer.

[0090] Although the present disclosure has described particular embodiments and methods in general terms, alternatives and substitutions of those embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of the embodiments of the examples does not define or constrain the present disclosure. Other changes, substitutions, and modifications are possible without departing from the spirit and scope of the present disclosure as defined by the following claims.

Claims

1. a secure substrate (205) having a viewing side (209) and a back side (211), the secure substrate (205) including a micro-optical system (305, 321) having micro-structures providing an optically variable effect (OVE) on the viewing side (209) and integrated within the secure substrate (205); a protective layer (225) disposed facing the back side (211); a mask layer (215) disposed between the protective layer (225) and the back side (211) of the secure substrate (205); A security document (200) comprising: A security document (200) in which the secure substrate (205) provides a structural foundation for the protective layer (225) and the mask layer (215) of the security document (200), the structural foundation being formed by the protective layer (225) and the mask layer (215), which are made of the same material, being integrated with each other on the secure substrate (205).

2. 2. The security document (200) of claim 1, wherein the protective layer (225) comprises a second secure substrate (465) spaced apart from the secure substrate (205) with the mask layer (215) interposed therebetween.

3. The security document (200) of claim 1, wherein the mask layer (215) comprises a layer of opaque material.

4. The security document (200) of claim 1, wherein the mask layer (215) comprises a layer of reflective material.

5. The security document (200) of claim 1, wherein the mask layer (215) includes a window (217).

6. a patch (245) including an optical indicia of authenticity (247); the patch (245) is visible through the window (217) in the mask layer (215); The security document (200) of claim 5.

7. 7. The security document (200) of claim 6, wherein the optical indicia (247) of authenticity provided by the patch (245) comprises at least one of a watermark, an offset printed pattern, an intaglio printed pattern, or an optical security element.

8. 10. The security document (200) of claim 1, further comprising a tactile mechanism (445, 455, 460) disposed on the viewing side (209) of the secure substrate (205).

9. 10. The security document (200) of claim 8, wherein the tactile feature (445) comprises a material printed on the viewable side (209) of the secure substrate (205).

10. 10. The security document (200) of claim 9, wherein the tactile feature (445) comprises intaglio printing on the viewing side (209) of the secure substrate (205).

11. The microstructures of the secure substrate (205) are repeatedly structured in a layer of a common material of the secure substrate (205), the microstructures of the secure substrate (205) being A layer of focusing elements (409); A layer of image icons (413); an optical spacer (415); the layer of focusing elements is disposed on a first side of the optical spacer (415); the layer of graphical icons includes graphical icons disposed proximate to focal points of focusing elements of the layer of focusing elements; The security document (200) of claim 1.

12. 12. The security document (200) of claim 11, wherein the layer of focusing elements comprises refractive focusing elements.

13. 12. The security document (200) of claim 11, wherein the layer of focusing elements comprises reflective focusing elements.

14. 12. The security document (200) of claim 11, wherein the layer of graphical icons is disposed on a second side of the optical spacer (415).

15. 12. The security document (200) of claim 11, wherein said optical spacer (415) is integral with said layer of focusing elements.

16. 12. The security document (200) of claim 11, wherein said layer of graphical icons is integral with said layer of focusing elements.

17. 17. A security document (200) according to claim 16, wherein the image icons of said layer of image icons are provided as relief structures in focusing elements of said layer of focusing elements.

18. 12. The security document (200) of claim 11, further comprising a sealing layer (450) disposed on the viewing side (209) of the secure substrate (205).

19. 20. The security document (200) of claim 18, further comprising a tactile feature (460) provided as a variation in thickness of the sealing layer (450).

20. 12. The security document (200) of claim 11, wherein the optical spacer (415) comprises a sheet of transparent polymer.

21. 21. The security document (200) 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 the OVE includes a Moire magnification effect.

23. 2. The security document (200) of claim 1, wherein the secure substrate (205) includes an area exhibiting total transparency that enables static features disposed on or below a back side (211) of the secure substrate (205) to be visible through the view side (209) of the secure substrate (205).

24. 24. The security document (200) of claim 23, further comprising a static feature printed on the back side (211) of the secure substrate (205).

25. 24. The security document (200) of claim 23, further comprising a static mechanism for changing color in said mask layer (215) depending on viewing direction.

26. 2. The security document (200) of claim 1, wherein the mask layer (215) and the protective layer (225) are provided as a single layer of material bonded to the back side (211) of the secure substrate (205).

27. 10. The security document (200) of claim 1, further comprising a machine-readable security feature (473).

28. Further comprising a tactile mechanism (445, 455, 460); 2. The security document (200) of claim 1, wherein the tactile features (445, 455, 460) are recorded by one or more of a window (217), a patch (245) in the mask layer (215), a feature in a printed layer, or the OVE.

Images