# US 12,005,728 B2 · Use of nanoparticles to tune index of refraction of layers of a polymeric matrix to optimize microoptic (MO) focus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,005,728 B2 - Document ID: US12005728B2 - Status: Granted - Kind: B2 - Application number: 17/612,962 - Filed: 2020-05-20 - Published: 2022-07-21 - Granted: 2024-06-11 - Earliest claimed: 2019-05-20 - Assignees: Crane Co. - Applicants: Crane & Co., Inc. - Inventors: Nancy J. Gettens; Jonathan D. Gosnell - Web page: https://patentgrep.com/patent/US12005728B2 ## CPC - B42D 25/324: Reliefs - B42D 25/36: comprising special materials - B42D 25/373: Metallic materials - C08F 265/06: Polymerisation of acrylate or methacrylate esters on to polymers thereof - C08F 283/065: {on to unsaturated polyethers, polyoxymethylenes or polyacetals} - C08K 3/105: Compounds containing metals of Groups 1 to 3 or of Groups 11 to 13 of the Periodic Table - C08K 3/22: of metals - C08K 3/30: Sulfur-, selenium- or tellurium-containing compounds - D21H 19/385: {Oxides, hydroxides or carbonates} - D21H 19/58: Polymers or oligomers of diolefins, aromatic vinyl monomers or unsaturated acids or derivatives thereof - D21H 21/40: Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper (watermarking B41M3/10, D21F1/44; security printing B41M3/14; securities or banknotes characterised by colour effects B42D25/29, B42D25/30; testing paper currency or valuable papers for genuineness G07D7/00) - D21H 21/52: Additives of definite length or shape - G02B 1/041: {Lenses} - G02B 3/0037: {characterized by the distribution or form of lenses} - G02B 27/16: used as aids for focusing - B42D 25/23: Identity cards - B42D 25/24: Passports - B42D 25/29: Securities; Bank notes - B42D 25/351: Translucent or partly translucent parts, e.g. windows - B42D 25/425: by deformation, e.g. embossing - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - C08K 2003/2227: {of aluminium} - C08K 2003/2241: {Titanium dioxide} - C08K 2003/2244: {of zirconium} - C08K 2003/3036: {of zinc} - B42D: BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES ## Abstract A security device (100, 600, 700) includes one or more arrangements of image icons (100a, 110b, 615, 715), one or more arrangements of refractive image icon focusing elements (120, 605, 705), and a sealing layer (127, 600, 1005) which includes an organic resin and nanoparticles. Further, the one or more arrangements of refractive image icon focusing elements is disposed above the one or more arrangements of image icons such that a portion of the one or more arrangements of refractive image icon focusing elements forms a synthetic image of a portion of the one or more arrangements of image icons. Still further, the one or more arrangements of refractive image icon focusing elements contact the sealing layer along a non-planar boundary. ## Claims ### Claim 1 A security device comprising: one or more arrangements of image icons; one or more arrangements of refractive image icon focusing elements; and a sealing layer comprising an organic resin and nanoparticles, wherein the one or more arrangements of refractive image icon focusing elements is disposed above the one or more arrangements of image icons such that a portion of the one or more arrangements of refractive image icon focusing elements forms a synthetic image of a portion of the one or more arrangements of image icons, wherein the one or more arrangements of refractive image icon focusing elements contact the sealing layer along a non-planar boundary, and wherein the nanoparticles comprised in the sealing layer are dispersed in the sealing layer and affect a geometry of the refractive image icon focusing elements. ### Claim 2 (depends on 1) The security device of claim 1, wherein the nanoparticles comprise one or more of aluminum oxide, zirconium dioxide, titanium dioxide, zinc sulfide or zinc telluride. ### Claim 3 (depends on 1) The security device of claim 1, wherein the organic resin comprises an acrylate monomer. ### Claim 4 (depends on 1) The security device of claim 1, wherein the organic resin comprises an acrylate oligomer. ### Claim 5 (depends on 1) The security device of claim 1, wherein the organic resin comprises one or more of a phenoxy benzyl acrylate, an o-phenlyphenoxyethyl acrylate, a phenylthioethyl acrylate, a bis-phenylthioethyl acrylate, a cumyl phenoxyl ethyl acrylate, a biphenylmethyl acrylate, a bisphenol a epoxy acrylate, a fluorene-type acrylate, a brominated acrylate, a halogenated acrylate or a melamine acrylate. ### Claim 6 (depends on 1) The security device of claim 1, wherein the organic resin comprises one or more of isodecyl acrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polyester tetraacrylate, trimethylolpropane triacrylate or hexanediol diacrylate. ### Claim 7 (depends on 1) The security device of claim 1, wherein the organic resin does not include a polarizing element. ### Claim 8 (depends on 1) The security device of claim 1, wherein the sealing layer has an index of refraction of 1.5 or higher. ### Claim 9 (depends on 1) The security device of claim 1, wherein the sealing layer has an index of refraction of 1.6 or higher. ### Claim 10 (depends on 1) The security device of claim 1, wherein a refractive image icon focusing element of the one or more arrangements of refractive image icon focusing elements has a diameter of greater than 30 microns. ### Claim 11 (depends on 1) The security device of claim 1, further comprising a spacer layer disposed between an arrangement of refractive image icon focusing elements and an arrangement of image icons, wherein the spacer layer comprises nanoparticles. ### Claim 12 (depends on 1) The security device of claim 1, further comprising a spacer layer integrated with an arrangement of refractive image icon focusing elements. ### Claim 13 (depends on 1) The security device of claim 1, further comprising two or more arrangements of refractive image icon focusing elements in contact along one or more non-planar boundaries. ### Claim 14 (depends on 1) The security device of claim 1, wherein the security device has a thickness of 50 microns or less. ### Claim 15 (depends on 1) The security device of claim 1, further comprising a machine-readable security device. ### Claim 16 (depends on 1) A security document comprising the security device of claim 1. ### Claim 17 A security device comprising: one or more arrangements of image icons; and a layer of one or more arrangements of refractive image icon focusing elements, the one or more arrangements of refractive image icon focusing elements comprising a mixture of an organic resin and nanoparticles, wherein the one or more arrangements of refractive image icon focusing elements is disposed above the one or more arrangements of image icons such that a portion of the one or more arrangements of refractive image icon focusing elements forms a synthetic image of a portion of the one or more arrangements of image icons, wherein the mixture of the organic resin and nanoparticles has an index of refraction greater than 1.5, and wherein the nanoparticles are dispersed in the layer of the one or more arrangements of refractive image icon focusing elements and affect a geometry of the refractive image icon focusing elements. ### Claim 18 (depends on 17) The security device of claim 17, wherein the organic resin has an index of refraction of less than 1.5. ### Claim 19 (depends on 17) The security device of claim 17, wherein the nanoparticles comprise one or more of aluminum oxide, zirconium dioxide, titanium dioxide, zinc sulfide or zinc telluride. ### Claim 20 (depends on 17) The security device of claim 17, wherein the organic resin comprises an acrylate monomer.