# US 10,310,152 B2 · Optical effect structures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,152 B2 - Document ID: US10310152B2 - Status: Granted - Kind: B2 - Application number: 15/562,907 - Filed: 2016-03-31 - Published: 2018-10-04 - Granted: 2019-06-04 - Earliest claimed: 2015-03-31 - Applicants: Andrew Richard Parker - Inventors: Andrew Richard Parker - Web page: https://patentgrep.com/patent/US10310152B2 ## CPC - G02B 5/286: {having four or fewer layers, e.g. for achieving a colour effect} - B29D 11/0074: {Production of other optical elements not provided for in B29D11/00009- B29D11/0073} - B29D 11/00894: {colouring or tinting} - G02B 1/14: Protective coatings, e.g. hard coatings - G02B 5/0226: {having particles on the surface} - G02B 5/0294: {adapted to provide an additional optical effect, e.g. anti-reflection or filter} - G02B 5/0816: {Multilayer mirrors, i.e. having two or more reflecting layers (G02B5/0883, G02B5/0891 take precedence)} - G02B 5/26: Reflecting filters (G02B5/28 takes precedence) - B05D 5/06: to obtain multicolour or other optical effects (B05D5/02 takes precedence) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) ## Abstract An optical coating structure is provided that when applied to a surface of an object to imparts a color to the object, the optical coating structure comprising: a base layer; a reflector on the base layer; and profile elements on the base layer under the reflector, the profile elements having a width and length which are each in the range of 5 to 500 μm in size, and being arranged in non-periodic manner or a periodic manner. The reflector may be a multilayer structure of alternating dielectric materials. A method of forming the optical coating structure is also provided. ## Claims ### Claim 1 An optical coating structure that when applied to a surface of an object imparts a structural color to the object wherein the color remains substantially the same to an observer over a broad range of viewing angles, the optical coating structure comprising: a base layer; a multilayer reflector on the base layer to impart the color; and profile elements on the base layer under the reflector wherein the reflector conforms to the surface profile of the profile elements, the profile elements having a width and length which are each in the range of 5 to 500 μm in size, and being arranged in non-periodic manner such that the profile elements are configured to avoid diffraction effects, wherein the profile elements are shaped so that greater than 50% of the surface area of the reflector is approximately normal to the incoming light when the light is incident at the normal to the plane of the surface and shaped so that greater than 30% of the surface area of the reflector is approximately normal to the incoming light when the light is incident at an angle of up to 30 degrees, wherein the profile elements reduce the multilayer reflector's normal property of color change with changing viewing angle. ### Claim 2 (depends on 1) An optical coating structure according to claim 1, wherein the base layer is a black colored material, or a transparent material to visible light. ### Claim 3 (depends on 1) An optical coating structure according to claim 1, wherein the profile elements have a height which is in the range of 0.1 to 50 μm. ### Claim 4 (depends on 1) An optical coating structure according to claim 1, wherein the profile elements are an array of overlapping bumps, or are a non-periodic array of indentations. ### Claim 5 (depends on 1) An optical coating structure according to claim 1, wherein the multilayer reflector comprises layers of higher and lower refractive index materials, wherein the multilayer reflector consists of less than 20 layers, wherein the multilayer reflector is configured to produce a reflection having a peak wavelength in the range of 350 to 800 nm, and wherein there is no break in the continuity of the layers of the reflector. ### Claim 6 (depends on 1) An optical coating structure according to claim 1, wherein the width and/or length of at least 50% of the profile elements is 10 to 100 times the thickness of the reflector; wherein the average period between adjacent profile structures is between 5 and 100 μm, and wherein at least 60% by area of the profile elements have a width and length which are each in the range of 5 to 100 μm in size. ### Claim 7 (depends on 1) An optical coating structure according to claim 1, wherein the profile elements have a ratio of height and length dimensions between 1:2 and 1:100. ### Claim 8 (depends on 1) An optical coating structure according to claim 1, wherein the structure comprises a protection layer on the upper surface of the reflector, which is a layer of SiO2, about 1 μm thick, or is a layer of poly(p-xylylene) polymer. ### Claim 9 (depends on 1) An optical coating structure according to claim 1, wherein the structure comprises an additional coating on the upper surface of the multilayer reflector which is configured to shift incident light towards a normal of the multilayer reflector. ### Claim 10 (depends on 9) An optical coating structure according to claim 9, wherein the additional coating comprises a material that has been cured after application, and wherein the additional coating comprises an acrylic material. ### Claim 11 (depends on 1) An optical coating structure according to claim 1, wherein the base layer is an acrylic material. ### Claim 12 (depends on 1) An object comprising the optical coating structure of claim 1, wherein the optical coating structure is incorporated on a surface of the object to impart a structural color to the object, and wherein more than 50% of a surface of the object incorporates the optical coating structure. ### Claim 13 (depends on 12) An object accordingly to claim 12, wherein the object is a housing of a portable electrical device or wherein the object is a sheet of flexible material for use in articles of manufacture. ### Claim 14 A method of forming an optical coating structure that when applied to a surface of an object imparts a structural color to the object, wherein the color remains substantially the same to an observer over a broad range of viewing angles, the method comprising: providing a base layer, the base layer having profile elements thereon, the profile elements having a width and length which are each in the range of 5 to 500 μm in size, and being arranged in a non-periodic manner such that the profile elements are configured to avoid diffraction effects, wherein the profile elements are shaped so that greater than 50% of the surface area of the reflector is approximately normal to the incoming light when the light is incident at the normal to the plane of the surface and shaped so that greater than 30% of the surface area of the reflector is approximately normal to the incoming light when the light is incident at an angle of up to 30 degrees; and depositing a multilayer reflector on the base layer to impart the color, wherein the reflector conforms to the surface profile of the profile elements and wherein the profile elements reduce the multilayer reflector's normal property of color change with changing viewing angle. ### Claim 15 (depends on 14) A method as claimed in claim 14, wherein an acid-etching process is used to form a mold for forming the profile elements. ### Claim 16 (depends on 14) A method as claimed in claim 14, wherein plasma coating process is used to deposit multiple layers to form the reflector, and wherein the plasma coating process deposits between 2 and 8 layers of alternating dielectric materials. ### Claim 17 (depends on 14) A method as claimed in claim 14, including a step of depositing a protection layer on to a surface of the reflector. ### Claim 18 (depends on 14) A method as claimed in claim 14, including a step of depositing an additional coating on to a surface of the multilayer reflector, the material of the additional coating being selected to shift incident light towards a normal of the multilayer reflector. ### Claim 19 (depends on 14) A method as claimed in claim 14, wherein the method includes the step of bending the base layer with profile elements already formed thereon.