Micro-optic security device with absolute registration

Abstract

To provide technology related to anti-counterfeiting of secure and / or expensive documents including banknotes, passports and tickets.SOLUTION: A micro-optic security device (100) comprises a planar array (105) of micro-optical focusing elements and a first arrangement (120) of image icons, each image icon (121) of the first arrangement of image icons includes a light-cured material region. Furthermore, the first arrangement of image icons can be visually recognized through the planar array of micro-optic focusing elements across a range of predetermined first viewing angles relative to the micro-optic security device, and the first arrangement of image icons cannot be visually recognized through the planar array of micro-optic focusing elements across a range of predetermined second viewing angles relative to the micro-optic security device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure generally relates to the prevention of forgery of secure and / or expensive documents such as banknotes, passports, and tickets. More specifically, the present disclosure relates to a micro-optical security device involving absolute alignment between a light-collecting element and individual micro-optical layers enlarged by the light-collecting element.

Background Art

[0002] Certain documents, including banknotes and some government-issued documents, but not limited thereto, utilize a micro-optical security device comprising a plurality of small-scale light-collecting elements (e.g., microlenses), each of the light-collecting elements having a footprint, and in that footprint, visual information is provided to generate a synthetic image visible to a viewer of the document. The visual information within the footprint of any given lens is generally too small to be seen by the human eye, but by the light-collecting operation of each of the plurality of light-collecting elements, a portion of the visual information provided within the footprint of each light-collecting element is displayed in a form visible to humans (sometimes referred to as a "synthetically enlarged" image, or "synthetic image"). This humanly visible display provides an indelible mark indicating the authenticity of the document.

Summary of the Invention

[0003] By controlling the collective dimensional characteristics (e.g., pitch, angle) of the visual information placed under the footprints of multiple light - collecting elements, the appearance of the visible display provided by the micro - optical system can be adjusted. For example, by adjusting the repetition period between items of visual information (e.g., icons) with respect to the pitch or repetition period of the light - collecting elements, the perceived distance of the visible display (in some embodiments, a synthetic image) with respect to the plane of the document can be adjusted such that the display appears to "float" above the document or to be at a depth below the document. Similarly, by slightly rotating the repetition axis of the visual information with respect to the repetition axis of the multiple light - collecting elements, a visual effect due to ortho - parallax (perpendicular parallax) can be achieved. Here, the tilt of the viewing perspective along one axis causes a position shift in the visible display along the orthogonal axis.

[0004] The wide range of visual effects and characteristics of the visible display provided by the micro - optical security system can be generated by controlling the intensive spatial relationship between the visual information and the light - collecting elements. However, absolute alignment, i.e., the skill of placing visual information at a specific position within the footprint of the light - collecting element, and, implicitly, the skill of providing a visible display at a predefined viewing angle, remain a cause of technical challenges and opportunities for improvement.

[0005] This disclosure provides a micro - optical security device with absolute alignment.

[0006] In the first embodiment, the micro-optical security device includes a planar array of micro-optical focusing elements and a first array of image icons, where each image icon in the first array of image icons includes a region of a light-cured material. Further, the first array of image icons is visible through the planar array of micro-optical focusing elements over a predetermined first field-of-view angle range with respect to the micro-optical security device. Also, the first array of image icons is not visible through the planar array of micro-optical focusing elements over a predetermined second field-of-view angle range with respect to the micro-optical security device.

[0007] In the second embodiment, a method of manufacturing a micro-optical system includes applying a layer of a light-curable material to a first surface of the micro-optical system that has a fixed relationship with a planar array of focusing elements, where the first surface is disposed proximate to one or more focal points of the focusing elements in the planar array of focusing elements. The method further includes directing a first pattern of structured light toward the lens surface of the planar array of focusing elements until a first array of image icons in which a first portion of the light-curable material layer is cured is formed, and removing or inactivating uncured light-curable material from the first surface of the micro-optical system. Additionally, the first pattern of structured light is directed toward the lens surface of the planar array of focusing elements from a predetermined first field-of-view angle range with respect to the planar array of focusing elements. e material) layer is applied, the first surface being disposed proximate to one or more focal points of the focusing elements in the planar array of focusing elements. The method further includes directing a first pattern of structured light toward the lens surface of the planar array of focusing elements until a first array of image icons in which a first portion of the light-curable material layer is cured is formed, and removing or inactivating uncured light-curable material from the first surface of the micro-optical system. Additionally, the first pattern of structured light is directed toward the lens surface of the planar array of focusing elements from a predetermined first field-of-view angle range with respect to the planar array of focusing elements.

[0008] Other technical features will be readily apparent to those skilled in the art from the following drawings, description, and claims.

[0009] Prior to the following detailed description, it may be advantageous to present definitions of certain words and phrases used throughout this patent document. The term "couple" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not these elements are in physical contact with each other. "Include" )」and the terms “comprise” and derivatives thereof mean non-limiting inclusion. The term “or” is inclusive and means and / or. The phrase “associated with” and derivatives thereof mean “to 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”, “have a relationship to or with”, etc. Also, functions associated with a particular controller may be centralized or distributed, whether local or remote. The phrase “at least one of” when used with a list of items means that one or more different combinations of the listed items may be used and only one item in the list may be required. For example, “at least one of A, B, and C” includes any combination of A, B, C, A and B, A and C, B and C, and A and B and C. Definitions of other specific phrases are provided throughout this patent document. One of ordinary skill in the art should understand that, in most if not all cases, such definitions apply to the use of the terms so defined both before and after.

[0010] ​

[0011] To more fully understand the present disclosure and its advantages, reference is made to the following description taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0012]

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[0013] The FIGS. 1-7B described below and the various embodiments used to explain the principles of the present disclosure in this patent document are for illustrative purposes only and should in no way be construed as limiting the scope of the present disclosure.

[0014] FIG. 1 shows an example of a micro-optical system 100 according to a particular embodiment of the present disclosure.

[0015] Referring to the non-limiting embodiment of FIG. 1, at a basic level, the micro-optical system 100 includes a plurality of light collecting elements 105 (e.g., including the light collecting element 107) and an array of image icons 120 (e.g., including the image icon 121). According to various embodiments, each light collecting element of the plurality of light collecting elements 105 has a footprint where one or more image icons of the array of image icons 120 are disposed. In certain embodiments, the position of the image icons within the array of image icons 120 within the footprint of each of the plurality of light collecting elements 105 is associated with a predetermined range of viewing angles with respect to a coordinate system using the plane of the plurality of light collecting elements 105. By controlling the visibility of the array of image icons 120 over a predetermined range of viewing angles (with respect to the plane of the plurality of light collecting elements 105), the performance of the micro-optical system 100 is enhanced at least in the following aspects. Since the variation of the viewing angle related to the visible display created by the micro-optical system 100 is reduced, it becomes easier to detect counterfeits, and more complex visual effects (e.g., 3D effects) within the visible display can be realized. According to certain embodiments, the micro-optical system 100 can project a synthetically enlarged image, an image having a motion effect (e.g., when the image appears to change position within the visual plane), and an animation effect (e.g., the visual content projected by the system includes a view of at least one common visual element that continuously changes over a range of viewing angles, e.g., providing a "flip book" effect), or combinations thereof, but is not limited thereto.

[0016] According to certain embodiments, the plurality of light condensing elements 105 includes a planar array of micro-optical light condensing elements. In some embodiments, the light condensing elements of the plurality of light condensing elements 105 include micro-optical refractive light condensing elements (e.g., plano-convex lenses or GRIN lenses). The refractive light condensing elements of the plurality of light condensing elements 105 are manufactured from a photocurable resin having a refractive index in the range of 1.35 to 1.7 and have a diameter in the range of 5 μm to 200 μm in some embodiments. In various embodiments, the light condensing elements of the plurality of light condensing elements 105 include reflective light condensing elements (e.g., very small concave mirrors) having a diameter in the range of 5 μm to 50 μm. In this exemplary embodiment, the light condensing elements of the plurality of light condensing elements 105 are shown as including circular plano-convex lenses, but other refractive lens shapes, such as lenticular lenses, are also possible and are within the scope intended by the present disclosure.

[0017] As shown in the exemplary embodiment of FIG. 1, the array 120 of image icons includes a set of image icons (including image icon 121) disposed at predetermined positions within the footprint of the plurality of condenser elements 105. According to various embodiments, individual image icons of the array 120 of image icons include regions of photocurable material associated with the focal path of structured light (e.g., collimated UV light) passing through the plurality of condenser elements 105 from projection points associated with one or more predetermined field-of-view angle ranges. In some embodiments, individual image icons of the array 120 of image icons are not provided within a structured image icon layer. The term "structured image layer" as used in this disclosure encompasses a layer of material (e.g., a photocurable resin) embossed or otherwise formed to include structures (e.g., recesses, posts, grooves, or mesas) for positioning and holding image icon material. According to various embodiments, individual image icons of the array 120 of image icons are provided within a structured image layer and are simultaneously absolutely aligned with predetermined positions within the footprint of the condenser elements. In certain embodiments according to the present disclosure, one or more image icon elements of the array 120 of image icons have a "gumdrop" shape, and the sidewalls of the image icons are tapered inwardly toward the foci of the condenser elements of the plurality of condenser elements 105.

[0018] As shown in the exemplary embodiment of FIG. 1, in certain embodiments, the micro-optical system 100 includes an optical spacer 110. According to various aspects, the optical spacer 110 includes a film of substantially transparent material that functions to dispose the image icons of the array 120 of image icons within or around the focal plane of the condenser elements of the plurality of condenser elements 105. In certain embodiments according to the present disclosure, the optical spacer 110 includes a manufacturing substrate, one or more layers of photocurable material are applied onto the manufacturing substrate, and can then be selectively cured with structured light that has passed through the plurality of condenser elements 105.

[0019] According to various embodiments, the micro-optical system 100 includes regions 130 of one or more photo-cured protective materials that occupy the space between the image icons of the image icon array 120. In some embodiments, first, the image icon array 120 is formed (e.g., by selectively curing and removing a liquid photo-curable material on the optical spacer 110), and then a layer of transparent photo-curable material is applied to fill the space between the image icons of the image icon array 120 and subsequently flood-cured to form a protective layer. This protective layer protects the image icons from moving from their positions within the footprints of the condenser elements of the plurality of condenser elements 105. In certain embodiments, the photo-curable material used to form the image icon array 120 is a colored ultraviolet (UV) curable polymer. In some embodiments, as an alternative to the photo-curable material, the protective layer 130 may be formed from an adhesive material suitable for attaching the micro-optical system 100 to the substrate 150. According to various embodiments, by constructing the protective layer 130 from an adhesive, the harvesting-resistance of the micro-optical system 100 can be enhanced. This is because when attempting to harvest the micro-optical system 100, some or all of the image icons of the image icon array 120 separate from the micro-optical system 100 and remain adhered to the substrate 150, thereby visually impairing the micro-optical system 100.

[0020] In certain embodiments according to the present disclosure, the micro-optical system 100 includes a sealing layer 140. According to certain embodiments, the sealing layer 140 includes a thin layer of a substantially transparent material (e.g., a layer having a thickness of 2 μm to 50 μm), the thin layer having a bottom surface in contact with the condenser elements of the plurality of condenser elements 105 and an upper surface with less curvature variation than the plurality of condenser elements 105 (e.g., by being smooth or having a surface with a radius of curvature larger than that of the condenser elements for local undulations).

[0021] As shown in the non-limiting example of FIG. 1, in certain embodiments, the micro-optical system 100 can be attached to a substrate 150 to form a security document 160. According to various embodiments, the substrate 150 can be a sheet-like currency paper or a polymer substrate. According to some embodiments, the substrate 150 is a thin and flexible sheet of biaxially oriented polypropylene (BOPP) that is a polymer film. In various embodiments, the substrate 150 is part of a synthetic paper material such as TESLIN®. According to some embodiments, the substrate 150 is part of a polymer card material, such as a polyethylene terephthalate (PET) blank of a type suitable for creating credit cards and driver's licenses.

[0022] FIG. 2 is a diagram showing an example of footprints of a micro-optical security device and a light collecting element of the micro-optical security device according to various embodiments of the present disclosure.

[0023] Referring to the non-limiting example of FIG. 2, a security document 200 is shown. According to various embodiments, the security document 200 is a banknote. In some embodiments, the security document 200 is an identity document such as a page of a passport or a driver's license.

[0024] As shown in the exemplary embodiment of FIG. 2, the security document 200 includes a micro-optical security device 205 (e.g., the micro-optical system 100 of FIG. 1). According to certain embodiments, the micro-optical security device 205 is substantially coplanar with the security document 200, and a part or all of the micro-optical security device 205 is maintained in a sufficiently flat state to define a coordinate system 207 suitable for defining a viewing angle or viewing vector indicating the incident direction of the observer's line of sight of the micro-optical security device 205, or the direction in which light from the micro-optical security device 205 is directed. In this illustrative example, the micro-optical security device is depicted as a plane in a three-dimensional Cartesian coordinate system 207. Other coordinate systems and improvements for taking into account the curvature in the micro-optical security device 205 are possible and within the intended scope of the present disclosure.

[0025] As shown in the enlarged view 210 of a part of the micro-optical security device 205, the micro-optical security device 205 includes an array 215 of image icons (e.g., the array 120 of image icons of FIG. 1), and each image icon of the array of image icons includes a region of a photocurable material having a focus-tapered sidewall profile. According to various embodiments, as shown in the enlarged view 210, the micro-optical security device 205 further includes a planar array 220 of light collecting elements. In some embodiments according to the present disclosure, the micro-optical security device 205 is relatively flexible and can be bent to accommodate intended bends (e.g., bending of a banknote within a wallet, or bending while moving around a roller in a vending machine or an automated teller machine). Thus, the term "plane" as used in the present disclosure includes the property that, at the micro level (e.g., considering a millimeter-length portion of the micro-optical security device 205), the components of the micro-optical security device are considered to be planar.

[0026] According to various embodiments, one or more of the encapsulation layer 140, the plurality of light concentrating elements 105, the optical spacer 110, and the protective layer 130 are formed from a photocurable material that is a polymer matrix, and this material is applied to a flat surface in a liquid or "goo" form and then cured using light to form a harder and more dimensionally stable structure. Examples of materials for use in such a polymer matrix and having a refractive index of 1.5 or less include, but are not limited to, isodecyl acrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polyester tetraacrylate, trimethylolpropane triacrylate, and hexanediol diacrylate. Further examples of photocurable materials according to this embodiment include substantially transparent or clear, colored or colorless polymers such as acrylic, acrylated polyester, acrylated urethane, epoxy, polycarbonate, polypropylene, polyester, and urethane. Even further examples of materials that can be used in the polymer matrix according to some embodiments of the present disclosure include acrylate monomers, acrylate oligomers, O-phenylphenoxyethyl acrylate, phenylthioethyl acrylate, bis-phenylthioethyl acrylate, cumylphenoxyl ethyl acrylate, biphenylmethyl acrylate, bisphenol A epoxy acrylate, fluorene-type acrylate, brominated acrylate, halogenated acrylate, melamine acrylate, and combinations thereof, but are not limited thereto. According to a particular embodiment, the composition of the photocurable material is specially formulated to not include materials having a polarizing element such as iodine, bromine, chlorine, or sulfur.

[0027] In various embodiments according to the present disclosure, the refractive index of the material used to form one or more of the encapsulation layer 140, the plurality of light collecting elements 105, the optical spacer 110, or the protective layer 130 can be adjusted or tuned by adding or adjusting the concentration of nanoparticles in a material mixture (e.g., a polymer matrix) used to form the constituent layers of the micro-optical system 100. According to some embodiments, the refractive index of a particular constituent layer of the micro-optical system 100 can be adjusted, for example, by adding inorganic nanoparticles having a particle size of 100 nm or less to the mixture. Examples of inorganic nanoparticles that can be added to the material mixture include, but are not limited to, aluminum oxide, zirconium dioxide, titanium dioxide, zinc sulfide, or zinc telluride. According to certain embodiments, adding nanoparticles to the material mixture can increase the refractive index of the material mixture from less than 1.5 to greater than 1.7. In some embodiments, refractive indices greater than 1.7 are possible by adding nanoparticles to an organic resin.

[0028] In the non-limiting example of FIG. 2, the light collecting elements of the planar array 220 of light collecting elements are shown as refractive light collecting elements (in this example, plano-convex lenses), but other embodiments using other types of light collecting elements (e.g., reflective light collecting elements) are possible and within the intended scope of the present disclosure.

[0029] As shown by the further enlarged view 230, each light collecting element 240 of the planar array 220 of light collecting elements is associated with a footprint 250. According to various embodiments, the footprint 250 can include an area on which an image icon can be placed and on which light can be focused by the light collecting element 240. Depending on the embodiment, the area and shape of the footprint 250 can have the same extent as the light collecting element 240 (e.g., a circle having the same diameter and the same center). Alternatively, in certain embodiments, the footprint of the light collecting element can be larger than the light collecting element and can overlap the footprints of other light collecting elements. In some embodiments, the footprint 250 includes a subset of the area directly below the light collecting element 240.

[0030] In certain embodiments, within the footprint 250, one or more image icons 260 and 265 are disposed at positions within the footprint 250 that are associated with a predetermined field of view angle of the micro-optical security device 205. According to various embodiments, one or more image icons 260 and 265 are formed from regions of a photocurable material. In certain embodiments, the individual regions of the photocurable material have a "gumdrop-like" shape and have sidewalls that taper inwardly as the distance between the image icon and the light collecting element increases. In some embodiments, the sidewalls of the regions of the photocurable material may not exhibit the focal taper described above, and instead are substantially perpendicular to the plane of the surface on which the regions of the photocurable material are formed.

[0031] As suggested by the grid lines within the footprint 250, each of the image icons 260 and 265 occupies a predefined position within the area of the footprint 250. By occupying a predefined position within the footprint 250, each of the image icons 260 and 265 can be said to exhibit absolute registration. As used in this disclosure, the term "absolute registration" encompasses a further degree of alignment between the condenser element and the image icon that goes beyond aggregate registration. In a micro-optical system exhibiting aggregate registration, the collective dimensions of the layer of the condenser element and the layer of the image icon are aligned, and a visible display appears at an unknown viewing angle and (in some embodiments) varies (e.g., turns on and off) at a predefined angle with respect to the unknown viewing angle. However, in a system exhibiting aggregate registration, for a given footprint of a given condenser element, the position of the image icon within that footprint is not predetermined or known in advance. In contrast, in a system exhibiting absolute registration, the position of the image icon within a particular footprint is predetermined and associated with providing a particular "visible display" at a predefined viewing angle within a coordinate system (e.g., coordinate system 207). Thus, according to certain embodiments, a micro-optical system (e.g., the micro-optical security device 205) with absolute registration exhibits an unexpectedly high degree of angular control with respect to one or more visible displays provided by the micro-optical system.

[0032] In the exemplary embodiment of FIG. 2, an embodiment is described in which the image icons 260 and 265 within the footprint 250 each contain all of the characteristics of a visible display, but embodiments according to the present disclosure are not so limited. According to certain embodiments, the footprint 250 can include a control pattern, and areas of photocurable material corresponding to only a portion of the visible display can be provided within the footprint 250.

[0033] Figures 3A and 3B show an example of angle control for a micro-optical security device and a visible display provided by the micro-optical security device according to some embodiments of the present disclosure. For convenience of cross-reference, structures common to both Figures 3A and 3B are given the same numbers.

[0034] Referring to the non-limiting examples of Figures 3A and 3B, a first view 301 (shown in Figure 3A) and a second view 351 (shown in Figure 3B) of a security document 305 (e.g., security document 200 of Figure 2) are shown. According to various embodiments, the security document 200 includes a micro-optical security device 310 (e.g., micro-optical security device 205 of Figure 2) that indicates absolute alignment. As shown in the exemplary examples of Figures 3A and 3B, the security document 305 is held by the observer's right hand and is maintained in a substantially planar state such that the viewing angle can be represented as one or more of a set of vectors or angular coordinates relative to the coordinate system 315. In this non-limiting example, the coordinate system 315 is a three-dimensional Cartesian coordinate system, but other coordinate systems can be used to represent the viewing angles of the security document 305 and the micro-optical security device 310 and are within the intended scope of the present disclosure. For example, in certain embodiments, a coordinate system approximating local flatness can be assigned to a local region (e.g., a 1 mm square portion in one example) of the micro-optical security device 310 to account for curvature. Thus, a unique viewing vector in three-dimensional space can be assigned to each point of the security device.

[0035] As shown in the exemplary embodiments of FIGS. 3A and 3B, in the first view 301, the security document 305 and the micro-optical security device 310 are held such that an observer views the micro-optical security device 310 at a predetermined first viewing angle Θ1 shown in the drawing. When viewed at Θ1, the light collecting element of the micro-optical security device 310 provides a synthetically enlarged image of a portion of the footprint of the light collecting element (e.g., the image icon 260 in FIG. 2), and this image contains visual information related to the first visible display 320.

[0036] According to certain embodiments, in the second view 351, the security document 305 and the micro-optical security device 310 are held such that an observer views the micro-optical security device 310 at a predetermined second viewing angle Θ2 shown in the drawing. When viewed at Θ2, the light collecting element of the micro-optical security device 310 provides a synthetically enlarged image of a portion of the footprint of the light collecting element (e.g., the image icon 265 in FIG. 2), and this image contains visual information related to the second visible display 360.

[0037] In contrast to certain micro-optical systems that show only aggregated alignment, the absolute alignment between the light collecting element of the micro-optical security device 310 and the image icon means that the viewing angles Θ1 and Θ2 related to the first visible display 320 and the second visible display 360 are predetermined in a coordinate system (e.g., coordinate system 315). In contrast, in a system having only aggregated alignment, the difference between Θ1 and Θ2 (e.g., quantification of the change in viewing angle required to cause a switch between the first visible display 320 and the second visible display 360) can be determined in advance, but the uncertainty regarding the position of the image icon within the footprint of the light collecting element means that the values of Θ1 and Θ2 are not predetermined. In contrast, certain micro-optical systems according to embodiments of the present disclosure show the absolute alignment between the image icon and the light collecting element, which in particular facilitates a high degree of angular control over the presentation of visible displays by the micro-optical system.

[0038] Figures 4A and 4B illustrate certain technical challenges related to achieving angular control for visible displays in some micro-optical security devices. For ease of cross-reference, structures common to both Figures 4A and 4B are given like numbers.

[0039] Referring to the non-limiting embodiments of Figures 4A and 4B, a first view 400 (shown in Figure 4A) of a refractive focusing element 401 disposed on a first surface of an optical spacer 403 is shown. A structured image icon layer 405 is disposed on a second surface of the optical spacer 403. Dashed lines 407a and 407b indicate the boundaries of the footprint of the focusing element 401. In this exemplary embodiment, the footprint of the focusing element 401 has the same extent as around the focusing element 401, although in other embodiments it is possible for the footprint to be larger or smaller than the focusing element 401 and still be within the intended scope of the present disclosure.

[0040] According to certain embodiments, the structured image icon layer 405 includes a layer of material that defines a pattern of recesses, posts, mesas, and other structures in the material. In various embodiments, the structure of the structured image icon layer 405 is such that a subsequently applied (e.g., by doctor blading a resin into voids within the structured image icon layer 405) coloring material is placed and retained, thereby filling the negative space within the structured image icon layer. Referring to the non-limiting embodiments of Figures 4A and 4B, a region 409 of the coloring material is shown as being retained within the structure of the structured image icon layer 405 and occupying a position within a first offset 411 with respect to the right boundary 407b of the footprint of the focusing element 401.

[0041] Referring to the non-limiting embodiments of Figures 4A and 4B, in certain embodiments, a first viewing angle Θ aThe light that passes through the lens surface 413 of the light condensing element is focused by the light condensing element 401 on the region 409 of the coloring material. The term "lensing surface" used in the present disclosure encompasses both a curved boundary between regions of different refractive indices (e.g., in a system using a refractive light condensing element) and a curved region of a reflective material (e.g., in a system using a reflective light condensing element). According to a particular embodiment, the light condensing element 401 is part of a larger planar array of similar light condensing elements, and the structured image icon layer 405 is likewise part of a larger array of image icons. In some embodiments, the planar array of light condensing elements (including the light condensing element 401) and the larger array of image icons (including the structured image icon layer 405) synthetically expand a portion of the image icon layer to create a visible display.

[0042] The second view 450 (shown in FIG. 4B) shows some of the technical challenges associated with achieving angular control for the visible display provided by the micro-optical system when the alignment of the colored image icon to the light condensing element depends only on holding the coloring material within the structure of the structured image icon layer. As described elsewhere in the present disclosure, the light condensing element according to a particular embodiment of the present disclosure has a diameter of 5 μm to 50 μm and a relatively large footprint. Given the scale of the footprint of the light condensing element, in order to control the angular range through which an image icon can be seen through a particular light condensing element, the image icon needs to be positioned with micron or sub-micron accuracy. It is possible to control the relative distances between the structures within the structured icon layer in microns and sub-microns (e.g., by achieving intensive alignment), but reliably positioning the structured image icon layer with micron or sub-micron accuracy relative to the footprint of the array of micro-optical light condensing elements remains a significant technical challenge.

[0043] The technical problem related to aligning the structured icon layer with respect to a specific position within the footprint of the light collector element is shown with reference to the second view 450. As shown in the second view 450, for example, due to limited manufacturing tolerances, or other confounding factors that affect the accuracy of the structured icon layer relative to the array of light collector elements, the structure ured image icon layer 405 is shifted by a small distance Δ, such that region 409 is disposed within a new second offset 421 relative to the right boundary 407b of the footprint of the light collector element 401. As a result of region 409 being positioned at new coordinates within the footprint of the light collector element 401, in order for light passing through the lens surface 413 of the light collector element 401 to be focused onto region 409, the light must be angled at a different angle Θ b onto region 409. As a practical matter, the net effect of the uncertainty in the alignment of the position of region 409 within the footprint of the light collector element 401 includes that the angle of the visible display contributed by region 409 is not predetermined.

[0044] Figures 5A, 5B, and 5C show examples of passing structured light through a light collector element for a predetermined position within the footprint of the light collector element, according to various embodiments of the present disclosure, from three different viewpoints. For ease of cross-reference, like numbers are assigned to elements common to the plurality of figures of Figures 5A-5C.

[0045] According to certain embodiments of the present disclosure, it is possible to overcome technical problems related to achieving absolute alignment and achieving angular control of the presentation of a synthetically enlarged visible display. In certain embodiments according to the present disclosure, structured light is projected onto the lens surface of the light collecting elements of a planar array of light collecting elements from a projection angle corresponding to a predetermined field of view angle range. Here, the structured light is focused by the light collecting elements of the planar array of light collecting elements onto the uncured regions of the photocurable material within the footprint of the light collecting elements of the planar array of light collecting elements. Subsequently, either the uncured photocurable material is removed (e.g., by spray cleaning) or chemically inactivated, so that only the cured regions of the photocurable material are visible through the light collecting elements within the predetermined field of view angle range. In this way, the technical problems related to aligning the structured icon layer to a specified position with respect to the footprint of the light collecting elements of the planar array of light collecting elements are avoided, and a micro-optical system showing absolute alignment can be manufactured.

[0046] Referring to the non-limiting examples of FIGS. 5A - 5C, side view (FIG. 5C), bottom view (FIG. 5A), and perspective view (FIG. 5B) of the refractive light collecting element 501 disposed in a part of the optical spacer 503 are provided by the figures. According to certain embodiments, the light collecting element 501 is fixed to the optical spacer 503 and has a fixed relationship with respect to the surface of the optical spacer 503. In certain embodiments, the fixed relationship between the light collecting element 501 and the surface of the optical spacer 503 is achieved by applying a photocurable material layer to the optical spacer 503, embossing the photocurable material layer to form a lens surface, and curing the material in place. In some embodiments, the fixed relationship between the light collecting element 501 and the surface of the optical spacer 503 is achieved by forming both the light collecting element 501 and the optical spacer from a common layer of photocurable material and curing the formed layer to produce an integrated combination of the light collecting element and the optical spacer.

[0047] The light - collecting element 501 is associated with a footprint 505, and according to some embodiments, is associated with a footprint 505 having the same extent as the peripheral portion of the light - collecting element 501. According to some embodiments, the footprint 505 is smaller than the periphery of the light - collecting element 501. In certain embodiments, the footprint 505 delineates an area larger than the periphery of the light - collecting element 501.

[0048] As shown in the exemplary embodiments of FIGS. 5A - 5C, structured light (e.g., collimated light, light from a projector, or light that has passed through another arrangement of light - collecting elements) is projected onto the lens surface of the light - collecting element 501 at an angle (or range of angles) associated with a predefined field - of - view angle shown as Θ c in the figure. The lensing action of the light - collecting element 501 focuses the incident light onto an area 520 within the footprint 505. By creating an image icon that includes a cured region of a photocurable material proximate to the area 520 using the structured light passing through the light - collecting element 501, a micro - optical system with absolute alignment according to various embodiments of the present disclosure can be manufactured.

[0049] FIGS. 5A - 5C show specific embodiments for achieving angular control of a synthetically enlarged visible image in a micro - optical system using refractive light - collecting elements, but embodiments according to the present disclosure are not limited thereto, and there are other configurations of light - collecting elements such as reflective light - collecting elements. In addition, in some embodiments according to the present disclosure, the optical spacer 503 can be omitted, and a fixed relationship between the mounting surface of the image icon and the lens surface of the light - collecting element can be realized in another way. For example, depending on the geometry and refractive index of a plano - convex lens, the planar side of the plano - convex lens can define a surface having a fixed relationship with respect to the lens surface of the light - collecting element, and an image icon with absolute alignment can be formed thereon.

[0050] Figures 6A-6C illustrate the operation of a method for creating image icons of an array of image icons with absolute alignment, according to certain embodiments of the present disclosure. For ease of cross-reference, like numerals are given to a plurality of common structures among Figures 6A-6C.

[0051] Referring to the non-limiting examples of Figures 6A-6C, a light collecting element 601 (e.g., the plurality of light collecting elements 105 and the micro-optical system 100 of Figure 1) within a planar array of light collecting elements in a micro-optical security device is shown to be disposed on an optical spacer 603 such that the light collecting element 601 has a fixed relationship with the bottom surface 605 of the optical spacer 603. In a first operation 620 (shown in Figure 6A) of a method for creating image icons with absolute alignment, an uncured layer of a photocurable material 615 is applied to the bottom surface 605 of the optical spacer 603. In some embodiments, when performing operation 620, the photocurable material 615 is applied to the footprint of all of the light collecting elements of the light collecting element array of which the light collecting element 601 is a member. In various embodiments, the photocurable material 615 is applied only to a subset (e.g., a partial layer) of the footprint of the light collecting elements of the light collecting element array of which the light collecting element 601 is a member. As part of operation 620, structured light associated with a pattern (e.g., a pattern corresponding to a feature of a visible display provided by a micro-optical security system) is projected onto the lens surface 607 of the light collecting element 601 from a predetermined range of a first field of view angle (Θ d ~Θ e ). In some embodiments, the light collecting element 601 focuses light to a focal point 609, and the interaction between the focused light and the uncured layer of the photocurable material 615 generates a cured region 613 of the photocurable material that forms all or part of the image icons of the array of image icons. According to certain embodiments, the cured region 613 of the photocurable material has a focus-tapered sidewall profile. The term "focally tapered" as used in the present disclosure encompasses a reduction in the cross-section of the cured region of the photocurable material toward the focus of the light collecting element. When viewed under a microscope, a focus-tapered image icon may appear to have a shape like a "gumdrop".

[0052] As shown in the exemplary embodiments of FIGS. 6A-6C, in operation 630 (shown in FIG. 6B), the uncured photocurable material is removed from the bottom surface 605 of the optical spacer 603, leaving the image icon 631. In some embodiments, the uncured photocurable material is deactivated to visually contrast with the image icon 631. Since the image icon 631 occupies a predetermined position within the footprint of the condenser element 601, it is visible through the condenser element 601 within a predetermined range of the first viewing angle (i.e., Θ d ~Θ e ). Further, since the image icon 631 occupies a predetermined position within the footprint of the condenser element 601, it is not visible through the condenser element 601 within a predetermined range of the second viewing angle. More simply stated, by passing cured light through the condenser element to create the image icon 631, in certain embodiments according to the present disclosure, angular control (e.g., absolute alignment) with respect to visibility is achieved.

[0053] Referring again to the non-limiting embodiments of FIGS. 6A-6C, in operation 640 (shown in FIG. 6C), a protective layer 645 of the photocurable material is applied to the area outside the image icon 631 and flood cured. According to various embodiments, the protective layer 645 helps maintain alignment of the image icon with respect to a predetermined position within the footprint of the condenser element 601 by filling the space between the image icons, reducing the degree of freedom of movement of the image icons, and making it difficult for the image icons to come off the surface to which they are attached. Further, in some embodiments, the protective layer 645 forms a holding matrix that helps prevent the image icon 631 from separating from the bottom surface 605 of the optical spacer 603 during processing (e.g., in a reel to reel process) and during attachment to a substrate (e.g., substrate 150 of FIG. 1), enhancing the durability of the micro-optical system.

[0054] FIGS. 7A and 7B are within the footprint of a condenser element according to various embodiments of the present disclosure Shows the operation of a method for creating a second image icon. For ease of cross-reference, elements common to both FIGS. 6A and 6B are given the same reference numerals. According to certain embodiments, the second image icon within the footprint of the light collecting element can contribute to the operation of the micro-optical security device in a plurality of ways.

[0055] As a first example, when the first image icon is of a first color, placing a second image icon of a second color at a position within the footprint of the light collecting element near the first image icon, when a plurality of light collecting elements and the image icons are aggregated, can generate a region of a third color (the third color is a mixed color of the first color and the second color) within a synthetically enlarged visible display. As an example, using only red and blue image icons, a visible display having red, blue, and purple regions can be created.

[0056] As a second example, placing the second image icon within the footprint of the light collecting element can be done to support the micro-optical security device when providing a second (or multiple) visible display that appears or does not appear within a predefined range of viewing angles when a plurality of light collecting elements and the second image icon are aggregated. According to certain embodiments, the absolute alignment of the image icon within the footprint of the light collecting element enables the creation of a plurality of visible displays, each of which is visible within a predefined narrow range of viewing angles, thereby creating the appearance of a visible display that appears to be constantly moving (e.g., rotating) or changing in shape.

[0057] Referring to the non-limiting embodiments of FIGS. 7A and 7B, two operations of a method for creating a second image icon of a second color within the footprint 703 of the condenser element 705 are shown. According to a particular embodiment, in operation 701 (shown in FIG. 7A), a fresh layer 707 of uncured photocurable material of a second color is applied to a surface 709 (in this case, the underside of the optical spacer 711) on which the first image icon 713 is already formed, having a fixed relationship with respect to the condenser element 705. According to a particular embodiment, the photocurable material of the fresh layer 707 of uncured photocurable material has the same characteristic color as the first image icon 713. In some embodiments, the photocurable material of the fresh layer 707 of uncured photocurable material has a characteristic color different from that of the first image icon 713.

[0058] In some embodiments, as part of operation 701, a structured light pattern of structured light (e.g., a pattern corresponding to a visible feature of a second visible display) is projected onto the lens surface 715 of the condenser element from a predefined range of a second field of view angle (illustrated as ranging from Θ f to Θ g as shown). As a result of the structured light passing through the condenser element 705 from a predefined range of a second field of view angle, a cured region 717 of the photocurable material that forms the second image icon is formed within the footprint 703.

[0059] According to various embodiments, in operation 720 (shown in FIG. 7B), the uncured photocurable material within the photocurable material layer 707 is removed (e.g., by spray cleaning) or otherwise inactivated. The second image icon remains as a region of contrast that is visible through the condenser element 705 at a field of view angle within a predefined range of a second field of view angle and not visible through the condenser element 705 at one or more predefined ranges of field of view angles outside the predefined range of a second field of view angle.

[0060] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical security device comprising a planar array of micro - optical condenser elements and a first array of image icons, wherein each image icon of the first array of image icons includes a region of a photocurable material. The first array of image icons is visible through the planar array of micro - optical condenser elements over a predetermined first field - of - view angle range with respect to the micro - optical security device, and the first array of image icons is not visible through the planar array of micro - optical condenser elements over a predetermined second field - of - view angle range with respect to the micro - optical security device. In the non - limiting examples of FIGS. 7A and 7B, the uncured optical material of the first color (e.g., the material used to create image icon 713) is shown to be washed away after the formation of the first image icon, but embodiments according to the present disclosure are not so limited. In certain embodiments, a plurality of image icons associated with a plurality of field - of - view angles may be formed using a photocurable material of the first color without washing away the uncured material between the lights projected at different angles. In certain embodiments, the uncured material of the first color is washed away to create space for an uncured photocurable material of a second color.

[0061] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical security device in which a first array of image icons is associated with a first characteristic color and further includes a second array of image icons, wherein each image icon of the second array of image icons includes a second region of a photocurable material, the second array of image icons is visible through the planar array of micro - optical condenser elements over a predetermined third field - of - view angle range with respect to the micro - optical security device, and the second array of image icons is not visible through the planar array of micro - optical condenser elements over a predetermined fourth field - of - view angle range with respect to the micro - optical security device.

[0062] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical security device in which a second array of image icons is associated with a second characteristic color.

[0063] Examples of micro-optical security devices according to various embodiments of the present disclosure include a micro-optical security device in which each image icon of a first array of image icons is associated with a light collecting element of a planar array of micro-optical light collecting elements, each image icon of a second array of image icons is associated with a light collecting element of a planar array of micro-optical light collecting elements, each light collecting element of the planar array of micro-optical light collecting elements has a footprint, and the footprint of at least one light collecting element of the planar array of micro-optical light collecting elements includes the image icons of the first array of image icons and the image icons of the second array of image icons.

[0064] Examples of micro-optical security devices according to various embodiments of the present disclosure include a micro-optical security device in which a first array of image icons is arranged with respect to a planar array of micro-optical light collecting elements such that a part of the planar array of micro-optical light collecting elements forms a composite image of a part of the first array of image icons.

[0065] Examples of micro-optical security devices according to various embodiments of the present disclosure include a micro-optical security device in which each image icon of a first array of image icons is associated with a light collecting element of a planar array of micro-optical light collecting elements, each light collecting element of the planar array of micro-optical light collecting elements has a footprint, and a plurality of image icons of the first array of image icons are arranged at different positions within the footprint of each light collecting element to project at least one of a composite image, a three-dimensional image, an image having a moving effect, or an image having an animation effect.

[0066] Examples of micro-optical security devices according to various embodiments of the present disclosure include a micro-optical security device in which the image icons of a first array of image icons are arranged with respect to a planar array of micro-optical light collecting elements to generate a flicker effect having a predetermined "on" period.

[0067] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical security device having one or more regions of a photocurable protective material between image icons of a first array of image icons.

[0068] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical security device in which the image icons of the first array of image icons are not provided within a structured image icon layer.

[0069] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical security device in which the image icons of the first array of image icons are provided within a structured image icon layer.

[0070] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical security device in which the light - collecting elements of a planar array of micro - optical light - collecting elements include refractive light - collecting elements.

[0071] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical security device in which the light - collecting elements of a planar array of micro - optical light - collecting elements include reflective light - collecting elements.

[0072] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical security device in which the image icons of the first array of image icons include regions of a photocurable material having a focus - tapered side - wall profile.

[0073] Examples of micro - optical security devices according to various embodiments of the present disclosure include a micro - optical system in which a protective layer includes a layer of an adhesive material.

[0074] An example of a method for manufacturing a micro-optical system according to various embodiments of the present disclosure includes applying a layer of photocurable material to a first surface of the micro-optical system having a fixed relationship to a planar array of light collecting elements, the first surface being disposed proximate to one or more focal points of the light collecting elements of the planar array of light collecting elements; directing a first pattern of structured light toward the lens surface of the planar array of light collecting elements until a first portion of the layer of photocurable material is cured to form a first array of image icons; removing or deactivating uncured photocurable material from the first surface of the micro-optical system, the first pattern of structured light being directed toward the lens surface of the planar array of light collecting elements from a predefined range of a first field of view angle with respect to the planar array of light collecting elements.

[0075] An example of a method for manufacturing a micro-optical system according to various embodiments of the present disclosure includes directing a second pattern of structured light toward the lens surface of the planar array of light collecting elements until a second portion of the layer of photocurable material is cured to form a second array of image icons, the second pattern of structured light being directed toward the lens surface of the planar array of light collecting elements from a predefined range of a second field of view angle with respect to the planar array of light collecting elements.

[0076] An example of a method for manufacturing a micro-optical system according to various embodiments of the present disclosure includes a method in which the image icons of the first array of image icons are associated with a first characteristic color and the image icons of the second array of image icons are associated with a second characteristic color.

[0077] An example of a method for manufacturing a micro-optical system according to various embodiments of the present disclosure includes a method in which each image icon of the first array of image icons is associated with a light collecting element of the planar array of light collecting elements, each image icon of the second array of image icons is associated with a light collecting element of the planar array of light collecting elements, each light collecting element of the planar array of light collecting elements has a footprint, and the footprint of at least one light collecting element of the planar array of light collecting elements includes the image icons of the first array of image icons and the image icons of the second array of image icons.

[0078] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include a method in which a first array of image icons is arranged with respect to a planar array of light collecting elements such that a part of the planar array of light collecting elements forms a composite image of a part of the first array of image icons.

[0079] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include a method in which image icons of a first array of image icons are formed at predetermined positions on a first surface of the micro-optical system with respect to a planar array of light collecting elements to generate a flicker effect having a predetermined "on" period.

[0080] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include a method including a step of applying a layer of a photocurable protective material to a portion of the first surface between the image icons of the first array of image icons, and a step of photocuring the layer of the photocurable protective material.

[0081] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include a method including a step of applying a protective layer of an adhesive material to a portion of the first surface between the image icons of the first array of image icons.

[0082] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include a method in which image icons of a first array of image icons are formed in a structured image icon layer.

[0083] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include a method in which image icons of a first array of image icons are not formed in a structured image icon layer.

[0084] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include a method in which the light collecting elements of the planar array of light collecting elements include refractive light collecting elements.

[0085] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include methods in which the light collecting elements of a planar array of light collecting elements include reflective light collecting elements.

[0086] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include methods in which each image icon of a first array of image icons is associated with a light collecting element of a planar array of light collecting elements, each light collecting element of the planar array of light collecting elements has a footprint, and a plurality of image icons of the first array of image icons are arranged at different positions within the footprint of their respective light collecting elements to generate a composite image having a three-dimensional effect.

[0087] Examples of methods for manufacturing a micro-optical system according to various embodiments of the present disclosure include methods in which the image icons of a first array of image icons are formed with a focus-tapered sidewall profile.

[0088] None of the descriptions in this application should be construed as implying that any particular element, step, or function is an essential element that must be included in the claims. The scope of the patented subject matter is defined only by the claims. Further, none of the claims are intended to invoke 35 U.S.C. § 112, paragraph (f), unless the exact words "means for" are followed by a participle.

Claims

1. A micro-optical security device (100), comprising: a planar array (105) of light-collecting elements; and a first array (120) of image icons, each image icon (121) of the first array of image icons including a region of photocurable material; the first array of image icons being visible (320) through the planar array of light-collecting elements over a predetermined first field-of-view angle range with respect to the micro-optical security device, light incident on the micro-optical security device from within the predetermined first field-of-view angle range being focused by the planar array of light-collecting elements onto the first array of image icons; the first array of image icons being invisible (360) through the planar array of light-collecting elements over a predetermined second field-of-view angle range with respect to the micro-optical security device, light incident on the micro-optical security device from within the predetermined second field-of-view angle range being focused by the planar array of light-collecting elements outside of the first array of image icons; not comprising a structured image layer (405) including a layer of material embossed or otherwise formed so as to provide a structure for positioning and holding the image icon material, the image icons of the first array of image icons not being provided within the structured image layer (405); A micro-optical security device.

2. the first array of image icons being associated with a first characteristic color; further comprising a second array of image icons, each image icon (725) of the second array of image icons including a second region of photocurable material; the second array of image icons being visible (360) through the planar array of light-collecting elements over a predetermined third field-of-view angle range with respect to the micro-optical security device; the second array of image icons being invisible through the planar array of light-collecting elements over a predetermined fourth field-of-view angle range with respect to the micro-optical security device; The micro-optical security device according to claim 1.

3. The micro-optical security device according to claim 2, wherein the second array of image icons is associated with a second characteristic color.

4. Each light - collecting element of the planar array of the light - collecting elements has a footprint (250), The footprint of at least one light - collecting element of the planar array of the light - collecting elements includes image icons (260) of the first array of the image icons and image icons (265) of the second array of the image icons, Each image icon of the first array of the image icons is associated with a first position within the footprint of the light - collecting element of the planar array of the light - collecting elements, Each image icon of the second array of the image icons is associated with a second position within the footprint of the light - collecting element of the planar array of the light - collecting elements, The micro - optical security device according to claim 2.

5. The micro - optical security device according to claim 1, wherein the first array of the image icons is arranged with respect to the planar array of the light - collecting elements such that a part of the planar array of the light - collecting elements forms a composite image of a part of the first array of the image icons.

6. Each image icon of the first array of the image icons is associated with a light - collecting element of the planar array of the light - collecting elements, Each light - collecting element of the planar array of the light - collecting elements has a footprint, A plurality of image icons of the first array of the image icons are arranged at different positions within the footprint of the corresponding light - collecting element to project at least one of a composite image, a three - dimensional image, an image with a moving effect, or an image with an animation effect. The micro - optical security device according to claim 1.

7. The image icons of the first array of the image icons are configured to switch a visible display, The image icons of the first array of the image icons are not provided within the structured image layer (405). The micro - optical security device according to claim 1.

8. Further comprising a protective layer (130), The micro - optical security device according to claim 1, wherein the protective layer includes at least one of an adhesive layer applied to a part of the first surface or a photocured region of a protective material between the image icons of the first array of the image icons.

9. Do the light - collecting elements of the planar array of the light - collecting elements include refractive light - collecting elements, Or, do the light - collecting elements of the planar array of the light - collecting elements include reflective light - collecting elements, The micro - optical security device according to claim 1.

10. The image icons of the first array of the image icons include regions (713, 725) of a photocurable material having a focus-tapered sidewall profile, the micro-optical security device according to claim 1.

11. A method of manufacturing a micro-optical system, Applying a layer of photocurable material (615) to a first surface (709) of the micro-optical system having a fixed relationship with respect to a planar array (105) of light collecting elements, wherein the first surface is disposed close to one or more foci of the light collecting elements of the planar array of light collecting elements, the step of applying, Directing a first pattern of structured light towards a lens surface (715) of the planar array of light collecting elements until a first portion of the photocurable material layer is cured to form a first array of image icons, Removing or inactivating uncured photocurable material from the first surface of the micro-optical system, The first pattern of structured light is directed from a predetermined range of a first viewing angle with respect to the planar array of light collecting elements towards the lens surface of the planar array of light collecting elements, The image icons of the first array of the image icons are not provided within a structured image layer (405) including a layer of material formed by embossing or other means so as to have a structure for positioning and holding the image icon material, Light incident from the predetermined range of the first viewing angle is focused by the planar array of light collecting elements onto the first array of the image icons, Light incident from the predetermined range of the second viewing angle is focused by the planar array of light collecting elements outside the first array of the image icons, A method of manufacturing a micro-optical system.

12. Further comprising directing a second pattern of structured light towards the lens surface of the planar array of light collecting elements until a second portion of the photocurable material layer is cured to form a second array of image icons, The second pattern of structured light is directed from a predetermined range of a second viewing angle with respect to the planar array of light collecting elements towards the lens surface of the planar array of light collecting elements, The method of manufacturing a micro-optical system according to claim 11.

13. The image icons of the first array of the image icons are associated with a first characteristic color, The image icons of the second array of the image icons are associated with a second characteristic color, Method for manufacturing a micro-optical system according to claim 12.

14. Each light-collecting element of the planar array of light-collecting elements has a footprint (250), The footprint of at least one light-collecting element of the planar array of light-collecting elements includes the image icons (260) of the first array of the image icons and the image icons (265) of the second array of the image icons, Each image icon of the first array of the image icons is associated with a first position within the footprint of the light-collecting element of the planar array of light-collecting elements, Each image icon of the second array of the image icons is associated with a second position within the footprint of the light-collecting element of the planar array of light-collecting elements. Method for manufacturing a micro-optical system according to claim 12.

15. The method for manufacturing a micro-optical system according to claim 11, wherein the first array of the image icons is arranged with respect to the planar array of light-collecting elements such that a part of the planar array of light-collecting elements forms a composite image of a part of the first array of the image icons.

16. The image icons of the first array of the image icons are formed at predetermined positions on the first surface of the micro-optical system with respect to the planar array of light-collecting elements to switch a visible display, The image icons of the first array of the image icons are not formed within the structured image layer (405). Method for manufacturing a micro-optical system according to claim 11.

17. Further comprising the step of applying a protective layer (130) to a part of the first surface, The protective layer includes at least one of an adhesive layer applied to a part of the first surface or a flood-cured region of a photocurable protective material between the image icons of the first array of the image icons. Method for manufacturing a micro-optical system according to claim 11.

18. Do the light-collecting elements of the planar array of light-collecting elements include refractive light-collecting elements, Or, do the light-collecting elements of the planar array of light-collecting elements include reflective light-collecting elements? Method for manufacturing a micro-optical system according to claim 11.

19. Each image icon of the first array of the image icons is associated with a light-collecting element of the planar array of light-collecting elements, Each light-collecting element of the planar array of light-collecting elements has a footprint. A plurality of image icons of the first array of the image icons are arranged at different positions within the footprint of the corresponding condenser elements to project at least one of a composite image, a three-dimensional image, an image having a moving effect, or an image having an animation effect. A method of manufacturing a micro-optical system according to claim 11.

20. The image icons (713, 725) of the first array of the image icons are formed with a focus-tapered sidewall profile, and the method of manufacturing a micro-optical system according to claim 11.

Images