PATENT DOCUMENT

Publication Number: US-10502879-B1
Application Number: US-201715703846-A
Country: US
Kind Code: B1

Title: Systems with colored infrared-transparent layers

Abstract:
A system such as a vehicle system, building, or electrical equipment may be provided with one or more optical components. The optical components may include a near-infrared camera or other components that operate at near-infrared wavelengths. A visible-light-reflecting-and-infrared-light-transmitting layer may overlap the optical component. The visible-light-reflecting-and-infrared-light-transmitting layer may have an infrared-transparent substrate. A polymer layer may be formed on the substrate and may contain plasmonic nanoparticles that reflect white light. Colorant may be incorporated into the polymer layer or into an additional polymer coating to impart a desired color to the reflected white light and thereby provide the visible-light-reflecting-and-infrared-light-transmitting layer with a desired appearance.

Claims:
What is claimed is: 
     
       1. A system, comprising:
 an infrared optical component; and 
 a visible-light-reflecting-and-infrared-light-transmitting layer that overlaps the infrared optical component and that includes:
 a substrate layer; 
 a first coating on the substrate layer that is formed from a polymer containing plasmonic nanoparticles; and 
 a second coating on the first coating, 
 
 
       wherein the plasmonic nanoparticles include at least first and second plasmonic nanoparticles with first and second distinct light-scattering spectrums. 
     
     
       2. The system defined in  claim 1  wherein the plasmonic nanoparticles include at least first, second, and third plasmonic nanoparticles with first, second, and third distinct light-scattering spectrums. 
     
     
       3. The system defined in  claim 2  wherein the first plasmonic nanoparticles comprise spherical metal nanoparticles. 
     
     
       4. The system defined in  claim 3  wherein the second and third plasmonic nanoparticles comprise metal-coated-dielectric-core plasmonic nanoparticles. 
     
     
       5. The system defined in  claim 1  wherein the second coating comprises a polymer and a colorant in the polymer. 
     
     
       6. The system defined in  claim 5  wherein the plasmonic nanoparticles include solid metal nanoparticles and metal-coated-dielectric-core nanoparticles. 
     
     
       7. The system defined in  claim 5  wherein the colorant comprises dye, wherein the visible-light-reflecting-and-infrared-light-transmitting layer blocks at least 70% of visible light at wavelengths of 400-700 nm, and wherein the visible-light-reflecting-and-infrared-light-transmitting layer transmits at least 90% of infrared light at wavelengths of 900-1000 nm. 
     
     
       8. The system defined in  claim 5  wherein the colorant comprises pigment, wherein the visible-light-reflecting-and-infrared-light-transmitting layer blocks at least 70% of visible light at wavelengths of 400-700 nm, and wherein the visible-light-reflecting-and-infrared-light-transmitting layer transmits at least 90% of infrared light at wavelengths of 900-1000 nm. 
     
     
       9. A system, comprising:
 an infrared optical component; 
 a visible-light-reflecting-and-infrared-light-transmitting layer that overlaps the infrared optical component and that includes:
 a substrate layer, 
 a first coating on the substrate layer that is formed from a polymer containing plasmonic nanoparticles, and 
 a second coating on the first coating, and 
 
 vehicle structures adjacent to the visible-light-reflecting-and-infrared-light-transmitting layer that are color matched to the visible-light-reflecting-and-infrared-light-transmitting layer. 
 
     
     
       10. Apparatus, comprising:
 an infrared optical component; and 
 a visible-light-reflecting-and-infrared-light-transmitting structure that overlaps the infrared optical component and that includes:
 an infrared-transparent support structure; and 
 a layer on the infrared-transparent support structure that contains plasmonic nanoparticles and colorant, wherein the plasmonic nanoparticles are configured to reflect white light and wherein the colorant is configured to impart a color to the reflected white light. 
 
 
     
     
       11. The apparatus defined in  claim 10  wherein the layer on the infrared-transparent support structure comprises polymer and wherein the polymer contains the plasmonic nanoparticles and the colorant. 
     
     
       12. The apparatus defined in  claim 11  wherein the colorant comprises a colorant selected from the group consisting of: a dye and a pigment. 
     
     
       13. The apparatus defined in  claim 12  wherein the plasmonic nanoparticles comprise solid metal nanoparticles having diameters of less than 300 nm. 
     
     
       14. The apparatus defined in  claim 13  wherein the plasmonic nanoparticles comprise metal-coated plasmonic nanoparticles with dielectric cores. 
     
     
       15. The apparatus defined in  claim 14  wherein the infrared optical component comprises an infrared optical component selected from the group consisting of: a lidar device, an infrared camera, and infrared light source, and an infrared camera. 
     
     
       16. A vehicle, comprising:
 a vehicle body; 
 a support structure coupled to the vehicle body; 
 an infrared camera; 
 a visible-light-reflecting-and-infrared-light-transmitting layer supported by the support structure, wherein infrared light passes through the visible-light-reflecting-and-infrared-light-transmitting layer to the infrared camera and wherein the visible-light-reflecting-and-infrared-light-transmitting layer comprises:
 a polymer containing plasmonic nanoparticles that are configured to reflect white light; and 
 non-black colorant that colors the visible-light-reflecting-and-infrared-light-transmitting layer by coloring the reflected white light. 
 
 
     
     
       17. The vehicle defined in  claim 16  wherein the plasmonic nanoparticles comprise solid metal plasmonic nanoparticles having diameters of less than 300 nm. 
     
     
       18. The vehicle defined in  claim 17  wherein the plasmonic nanoparticles include first and second metal-coated nanoparticles with dielectric cores of first and second different respective diameters. 
     
     
       19. The vehicle defined in  claim 18  wherein the vehicle support structure comprises a portion of a vehicle dashboard. 
     
     
       20. The apparatus defined in  claim 10 , further comprising:
 vehicle structures adjacent to the visible-light-reflecting-and-infrared-light-transmitting structure that are color matched to the visible-light-reflecting-and-infrared-light-transmitting structure.

Description:
This application claims the benefit of provisional patent application No. 62/397,452, filed on Sep. 21, 2016, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to infrared-transparent structures, and, more particularly, to systems having colored infrared-transparent layers. 
     BACKGROUND 
     In vehicles, building systems, portable electronic devices, and other systems, it is often desirable to provide structures that modify the propagation of light. For example, it may sometimes be desirable to provide these systems with layers that block visible light while transmitting infrared light. 
     It can be challenging to incorporate infrared-transparent structures such as these into systems. If care is not taken, structures that are infrared-transparent will have an undesirable appearance. 
     SUMMARY 
     A system such as a vehicle system, building, or electrical equipment may be provided with one or more optical components. The optical components may include a near-infrared camera or other components that operate at near-infrared wavelengths. A visible-light-reflecting-and-infrared-light-transmitting layer may overlap an infrared optical component. Visible light may be blocked by this layer while infrared light that is emitted or detected by the infrared optical component may pass through the layer. 
     The visible-light-reflecting-and-infrared-light-transmitting layer may have an infrared-transparent substrate or other support structure that transmits infrared light. A polymer layer may be formed on the substrate. The polymer layer may contain plasmonic nanoparticles that reflect white light. Colorant such as colored dye or pigment may be incorporated into the polymer layer or into an additional polymer coating to impart a desired color to the reflected white light and thereby provide the visible-light-reflecting-and-infrared-light-transmitting layer with a desired appearance. Configurations in which a substrate layer or other structural support structure includes plasmonic nanoparticles and colorant may also be used. 
     Plasmonic nanoparticles in the visible-light-reflecting-and-infrared-light-transmitting layer may include solid metal nanoparticles and metal-coated-dielectric-core nanoparticles. Nanoparticle dimensions may be varied to adjust the absorption and scattering spectrums of the nanoparticles. Nanoparticles of several different types may be incorporated into a visible-light-reflecting-and-infrared-light-transmitting layer to supply the layer with the ability to reflect white light. This allows non-black colorant to be used in coloring the visible-light-reflecting-and-infrared-light-transmitting layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of an illustrative system in accordance with an embodiment. 
         FIG. 2  is a cross-sectional side view of an illustrative optical component such as an infrared camera in accordance with an embodiment. 
         FIG. 3  is a cross-sectional side view of an illustrative plasmonic particle formed from a solid material in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of an illustrative plasmonic particle formed from a metal coating on a dielectric core in accordance with an embodiment. 
         FIG. 5  is a graph showing illustrative scattering and absorption spectrums for a plasmonic particle of the type shown in  FIG. 3  in accordance with an embodiment. 
         FIGS. 6 and 7  are graphs showing illustrative scattering and absorption spectrums for plasmonic particles of the type shown in  FIG. 4  in accordance with an embodiment. 
         FIG. 8  is a graph showing how an infrared-transparent layer may incorporate plasmonic particles with different scattering spectrums in accordance with an embodiment. 
         FIG. 9  is a graph showing an absorption spectrum for an illustrative colorant such as a dye or pigment in accordance with an embodiment. 
         FIGS. 10, 11, and 12  are cross-sectional side views of illustrative visible-light-reflecting-and-infrared-light-transmitting layers in accordance with embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     A system may have infrared optical components. Visible-light-reflecting-and-infrared-light-transmitting layers may cover infrared optical components to protect the infrared optical components and to hide the infrared optical components from view. 
       FIG. 1  is a diagram of an illustrative system that may include an infrared-transparent layer that blocks visible light. System  10  of  FIG. 1  may be a building, a vehicle, electronic equipment such as a cellular telephone, laptop computer, or other portable electronic device, or other suitable system that includes electrical components. Some of the electrical components may be light-based components (sometimes referred to as optical components) that operate using infrared light. As an example, system  10  may include one or more infrared optical components such as components  20 . 
     Components  20  may be mounted in alignment with structures that are transparent to infrared light such as infrared-light-transparent layers (structures)  24 . Layers  24  may be fully or partially opaque at visible light wavelengths and may therefore sometimes be referred to as visible-light-blocking layers or visible-light-reflecting layers. For example, when viewed by a user of system  10  at visible light wavelengths, layers  24  may be black or may be white or have other non-black colors (e.g., blue, green, red, silver, yellow, gold, or other non-black colors). 
     System  10  may have support structures such as support structures  12 . In a vehicle, support structures  12  may form portions of a vehicle dashboard, exterior portions of a vehicle body, or portions of a vehicle window (as examples). In other systems, support structures  12  may form walls in an electronic device or building. 
     Infrared-transparent layers  24  may be mounted in openings in structures  12 . Infrared components such as components  20  may be mounted behind infrared transparent layers  24  so that components  20  are overlapped by layers  24  and therefore are protected by layers  24 . 
     Structures  12  may be configured to completely or partly surround an interior region such as interior region  14  and may separate interior region  14  from exterior region  16 . Viewers  26  may view layers  24 . Viewers  26  may include viewers that are located in interior region  14  (e.g., viewers  26  may include vehicle occupants when system  10  is a vehicle) and may include viewers that are located in exterior region  16  (e.g., viewers  26  may include external observers). 
     Layer  24  and surrounding portions of system  10  may be illuminated by interior and exterior light sources  18 . Light sources  18  may include light-emitting diodes, lamps, the sun, and other sources of light. Light  30  that is emitted by one or more of light sources  18  may include visible and infrared light. 
     Infrared-transparent layer  24  may be mounted in structures  12  so that portions of structures  12  are adjacent to layer  24 . For example, portions  121  of structures  12  in interior  14  may be adjacent to layer  24  in interior  14  and portions  12 E on the exterior of structures  12  may lie adjacent to layer  24  on the exterior surface of structures  12 . To enhance visual aesthetics, it may be desirable for the appearance of layers  24  to match the appearance of adjacent portions of system  10  such as portions  22  (e.g. it may be desirable for layers  24  and portions  22  to be color matched). 
     Portions (structures)  22  (e.g., external body structures and/or internal body structures in a vehicle) may sometimes be referred to as fascias, body structures, etc. Interior body structures in a vehicle (e.g., structures  121 ) may form portions of a vehicle dashboard or other mounting structures for layer  24 . Exterior body structures in a vehicle (e.g., structures  12 E) may form portions of a vehicle bumper, front, side, rear, or roof body panel or may form a portion of a window (e.g., a window structure that is covered with a colored ink or other opaque layer). As an example, in interior  14 , structures  22  may be vehicle dashboard structures or other vehicle interior structures and, in exterior  16 , structures  22  may form a portion of a bumper or other body part in a vehicle body. Structures  22  may also form part of a display in an electronic device such as a cellular telephone or computer (e.g., a glass display cover layer that is coated with opaque ink or other opaque masking material), may form part of a window, or may form other structures for mounting layers  24 . 
     Structures  22  may be formed from plastic, glass, metal, wood, fabric, other materials, or combinations of these materials. Structures  22  may be visually opaque and may have a variety of different colors. As an example, structures  22  may be black, silver, gray, white, blue, green, red, yellow, or may have other colors. To visually coordinate the appearance of structures  22  and layers  24 , it may be desirable for layers  24  to be at least partially opaque at visible wavelengths (e.g., it may be desirable for layers  24  to reflect and block at least 50%, at least 70%, at least 90%, at least 95%, or other suitable amount of visible light from 400-700 nm). 
     As an example, structures  22  may have a blue appearance and layers  24  may have a blue color or other appearance that is color coordinated with the appearance of structures  22 . To adjust the color of layers  24  to have a desired visual appearance when viewed by interior and exterior viewers  26 , layers  24  may include one or more materials absorb and reflect (scatter) visible light. For example, layers  24  may include a polymer or other material with particles that reflect visible light while transmitting infrared light and may include dyes, pigments, or other colorants that are transparent at infrared wavelengths and that impart a desired color to visible light that is scattered or otherwise reflected towards the viewer. 
     To provide layers  24  with satisfactory visible light scattering and absorption while ensuring satisfactory infrared transparency, it may be desirable to incorporate resonant scatterers such as plasmonic nanoparticles into layers  24 . The plasmonic nanoparticles can be configured to exhibit high visible light scattering and high infrared transparency, so that infrared light can reach optical components  20  that sense infrared light with low absorbance and low wavefront distortion. The high transparency of the plasmonic nanoparticles may also allow components  20  that emit infrared light to avoid undesired infrared light absorption in layers  24 . 
     Dyes, pigments, and other materials and structures in layers  24  may be configured to exhibit desired colors for viewers  26  when illuminated by light  30 . If, for example, it is desired for layers  24  to exhibit a blue color, a blue dye or blue pigment may be incorporate into layers  24  in addition to the plasmonic nanoparticles to produce a desired blue appearance. Particularly when layers  24  have lighter colors (white, silver, gold, red, green, blue, or other non-black colors), it may be desirable for at least a portion of layers  24  to reflect at least 20%, at least 50%, at least 70%, or other suitable amount of visible light at wavelengths of 400-700 nm, while blocking at least 20%, at least 50%, at least 70%, at least 80%, at least 90%, at least 95%, etc. of visible light at 400-700 nm. The ability to block visible light allows layers  24  to hide components behind layers  24  such as components  20  from view. The ability to reflect visible light from layers  24  may allow layers  24  to be colored as desired (e.g., the ability of plasmonic nanoparticles in layers  24  to scatter visible light back towards a viewer allows layers  24  to have a light non-black color such as blue, red, green, yellow, gold, white, etc.). 
     At the same time, satisfactory performance of infrared-light components  20  can be ensured by configuring the plasmonic nanoparticles and other materials in infrared-transparent layers  24  to exhibit substantial transparency at infrared light wavelengths. Layers  24  may, for example, exhibit transparency values of greater than 50%, greater than 70%, greater than 80%, greater than 90%, greater than 95%, less than 99.99%, or other suitable values at near infrared wavelengths (e.g., wavelengths above 800 nm, from 800-2500 nm, less than 3000 nm, 900-1000 nm, etc.). 
     If desired, more than one electrical component may be mounded under (behind) each infrared-transparent layer  24 . As shown in  FIG. 1 , for example, one or more components  32  may be mounted behind layers  24  in addition to infrared components  20 . Components  32  may include capacitive touch sensors, force sensors, temperature sensors, antennas or other wireless circuits, and/or other electrical components. 
     Infrared components  20  may be any suitable components that operate at infrared wavelengths. As an example, components  20  may include infrared proximity sensors. Infrared proximity sensors may include a light source such as an infrared light-emitting diode or infrared laser that emits infrared light and a corresponding infrared-light detector (e.g., a silicon photodetector) that measures reflections of the emitted infrared light from nearby objects such as objects  28 . Components  20  may also include lidar sensors. Lidar sensors, which may sometimes be referred to as light detection and ranging sensors or laser radar sensors, may have lasers that emit beams of infrared light, scanning systems that scan the emitted beams, and infrared light detectors that detect reflections of the emitted infrared light from objects  28 . If desired, components  20  may include infrared cameras, light sources that emit infrared light (e.g., arrays of infrared light-emitting diodes and/or infrared lasers that emit light for an infrared cameras), and/or other infrared components. 
       FIG. 2  is a cross-sectional side view of infrared component  20  in an illustrative configuration in which component  20  is an infrared camera. As shown in  FIG. 2 , camera (component)  20  may include a housing such as housing  60 . Infrared image sensor  62  may be formed from a silicon die having an array of image sensor pixels  64  (e.g., pixels with silicon photodetectors or other infrared-sensitive light detectors) or other digital infrared image sensor. A lens such as lens  66  may include one or more infrared-transparent lens elements and may be used to focus incoming infrared light  46  so that sensor  62  may capture images of objects  28 . Infrared components  20  may operate at near infrared wavelengths (e.g., wavelengths of 800-2500 nm, 800 nm or more, 940 nm, 900-1000 nm, 800-1000 nm, below 1000 nm, below 2000 nm, below 2500 nm, or other suitable near infrared wavelengths). 
     Plasmonic nanoparticles may be formed from conductive materials such as metal. An illustrative solid nanoparticle is shown in  FIG. 3 . Nanoparticle  70  of  FIG. 3  has a spherical shape. If desired, nanoparticles  70  may have other shapes (e.g. nanoplates). Nanoparticles  70  may be formed from silver, gold, or other metal. The size (e.g., diameter D of spherical plasmonic nanoparticle  70  of  FIG. 3 ) may be 20-200 nm, more than 10 nm, less than 250 nm, less than 300 nm, or other suitable diameter. Nanoparticle size affects the wavelengths of light that are scattered and absorbed by the nanoparticles, so adjustments to the diameter D of nanoparticle  70  can be used to produce desired light-scattering and absorption spectrums. 
     If desired, plasmonic nanoparticles may have dielectric cores surrounded by conductive coatings. As shown in  FIG. 4 , for example, plasmonic nanoparticle  70  may have a core  74  that is formed from a dielectric such as silica and may have a coating layer such as shell  72  that is formed from a metal (e.g., a silver or gold coating layer, etc.). The diameter D 1  of core  72  and the diameter D 2  of nanoparticle  70  may be adjusted to adjust the reflectivity and absorption spectrums of particle  70 . 
       FIG. 5  shows an illustrative scattering spectrum (curve  80 ) and illustrative absorption spectrum (curve  82 ) for solid nanoparticles (e.g., solid metal nanoparticles) of the type shown in  FIG. 3 . The shapes of curves  80  and  82  (e.g., the wavelengths associated with the peaks of curves  80  and  82 ) may be selected by adjusting nanoparticle diameter D. 
       FIG. 6  shows an illustrative scattering spectrum (curve  84 ) and illustrative absorption spectrum (curve  86 ) for a dielectric-core nanoparticle of the type shown in  FIG. 3 . The shapes of curves  84  and  86  may be adjusted by adjusting the values of D 1  and D 2  of  FIG. 4 . For example, if D 2  is maintained constant and D 2  is increased, the scattering spectrum represented by curve  84  in  FIG. 6  may shift to longer wavelengths and the absorption spectrum represented by curve  86  may shift to longer wavelengths, as illustrated by scattering curve (spectrum)  88  and absorption curve (spectrum  90 ), respectively, of  FIG. 7 . 
     To create a desired light-scattering spectrum for layers  24 , layers  24  may include multiple different types of plasmonic nanoparticles, each with a different respective light scattering spectrum and light absorption spectrum. Consider, as an example, a scenario in which layers  24  are provide with a polymer layer that includes three types of plasmonic nanoparticles. The polymer layer may, for example, include a first type of plasmonic nanoparticle (e.g., solid particle  70  of  FIG. 3 ) that exhibits light scattering spectrum  92  of  FIG. 8 , a second type of plasmonic nanoparticle (e.g., metal-coated-dielectric-core nanoparticle  70  of  FIG. 4 ) that exhibits light scattering spectrum  94 , and a third type of plasmonic nanoparticle (e.g., a particle of the type shown in  FIG. 4 , but having a thinner shell  72  than the second type of plasmonic nanoparticle) that exhibits light scattering spectrum  96 . The first type of nanoparticle may primarily scatter blue light, the second nanoparticle may primarily scatter green light, and the third nanoparticle may primarily scatter red light. Taken together, the first, second, and third nanoparticles may scatter light over substantially all of the visible light spectrum (400-700 nm) so that the polymer layer that includes the first, second, and third plasmonic nanoparticles will scatter white light and appear white and visually opaque, thereby hiding underlying optical components  20  from view. 
     If desired, dye, pigment, or other colorant may be added to layer  24  so that reflected white light from the plasmonic nanoparticles acquires a desired color (e.g., blue, red, green, other non-black colors, etc.). The relatively large amount of white light that is scattered by the first, second, and third plasmonic nanoparticles may be use to provide layers  24  with a desired light and colorful (non-black) appearance. There are three different types of plasmonic nanoparticles in layer  24  in the example of  FIG. 8 . If desired, fewer different types of plasmonic nanoparticles or more different types of plasmonic nanoparticles may be used. For example, a polymer layer or other layer with plasmonic nanoparticles in layer  24  may be provide with two different types of plasmonic nanoparticles or four or more different types of plasmonic nanoparticles. Moreover, the spectrums associated with the plasmonic nanoparticles may, if desired, be selected to provide layer  24  with a desired non-black color and/or to accentuate a particular color of layer  24  that is being provided by a colorant such as a dye or pigment. 
     An illustrative absorption spectrum  98  for a colorant (e.g., a dye or pigment contained in a polymer in layer  24 ) is shown in  FIG. 9 . In the example of  FIG. 9 , absorption spectrum  98  peaks at green wavelengths, so that light scattered from layer  24  has a reddish appearance. Other colors of dyes or pigments may be used, if desired. Dyes, pigments, and other colorants may be used to color layer  24  or part of layer  24  with any suitable color (e.g., blue, green, red, yellow, etc.). 
       FIGS. 10, 11, and 12  show illustrative configurations that may be used for forming layer  24 . Layer  24 , which may sometimes be referred to as a visible-light-blocking-and-infrared-light-transmitting layer or a visible-light-reflecting-and-infrared-light-transmitting layer, may be configured to pass infrared light while blocking and reflecting (scattering) visible light. 
     As shown in  FIGS. 10, 11, and 12 , layer  24  may be supported in support structure  12  (e.g., structures  22  of  FIG. 1  or other structures in device  10 ) so that layer  24  overlaps optical component  20 . Component  20  may be an infrared-light-emitting component (e.g., an illumination source formed from light-emitting diodes, lasers, or other devices that provides infrared illumination for a component such as an infrared camera or a light-emitting diode or an infrared laser or other light-emitting device in an infrared proximity sensor or lidar device) and/or may be a light-detecting component (e.g., a two-dimensional infrared image sensor such as image sensor  62  of  FIG. 2 , a silicon photodetector or other photodetector in an infrared proximity sensor or lidar device, or other light sensing component). During operation, infrared light associated with component  20  may pass through layer  24 . For example, component  20  may emit infrared light that passes through layer  24  and/or component  20  may receive infrared light that passes through layer  24 . In addition to transmitting infrared light, layer  24  may include plasmonic nanoparticles and other materials to provide layer  24  with desired visible light-blocking properties and a desired appearance (e.g., a desired color). 
     For satisfactory visible light blocking, layer  24  may block at least 30%, at least 50%, at least 70%, at least 90%, or at least 95%, or less than 99.9% of visible light at wavelengths 400-700 nm. For satisfactory infrared light transmission, layer  24  may transmit at least 50%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, or less than 99.99% of infrared light at wavelengths of 900-1000 nm or other near infrared wavelengths. 
     Layer  24  may include one or more support structures such as structural layer  100  of  FIG. 10 . Layer  100  may be a glass, ceramic, or plastic substrate layer or other layer of material that is transparent to infrared light. As an example, layer  100  may be formed from a polymer such as polycarbonate. Other polymers, glasses, ceramics, or other materials may be used in forming a structural support layer for layer  24 , if desired. 
     Layer  100  may be coated by coating layer  102 . Coating layer  102  may be include plasmonic nanoparticles  70 . With one illustrative configuration, coating layer  102  may be formed from a cured liquid polymer. In liquid form, layer  102  may include plasmonic nanoparticles  70 . When cured to form layer  102  of  FIG. 10 , the embedded nanoparticles can help scatter light, as described in connection with  FIG. 8 . If desired, layer  102  may be formed form multiple sublayers (e.g., multiple polymer layers each of which includes a different type of plasmonic nanoparticle, etc.), may be formed from molded thermoplastic resins, and/or may be formed from other suitable materials that serve as an infrared-transparent binder for plasmonic nanoparticles  70 . 
     Coating layer  104  of  FIG. 10  may be formed on top of layer  102  to provide layer  24  with a desired color. For example, coating layer  104  may include a colorant such as dye and/or pigment so that light that travels through coating layer  104  and that reflects (scatters) off of the plasmonic particles  70  of layer  102  may acquire a desired color. Coating layer  104  may, as an example, include a blue colorant in configurations in which layer  104  is being color matched to an adjacent blue structure in system  10  (see, e.g., adjacent structures  22  of  FIG. 1 ). In general, any suitable color of colorant may be incorporated into layer  104  (e.g., red colorant, green colorant, blue colorant, yellow colorant, etc.). 
     The visible light reflection (scattering) from plasmonic nanoparticles  70  can ensure that sufficient light passes through coating  104  to provide layer  24  with a desired appearance. For example, multiple different types of plasmonic nanoparticles or other suitable nanoparticles  70  may be incorporated into layer  102  to provide layer  102  with the ability to reflect white light. Layer  104  may be formed from a polymer that includes blue dye. With this configuration, the visible light that passes through layer  104  to layer  102  and the visible light that is reflected from layer  104  toward the viewer may acquire a desired blue color. The use of plasmonic nanoparticles in layer  102  to scatter white light may help ensure that the apparent color of layer  24  is not too dark (e.g., red, green, blue, yellow, and other non-black colors can be presented to a viewer). 
       FIG. 11  shows how plasmonic nanoparticles  70  may be incorporated into layer  104 . In this type of arrangement, plasmonic nanoparticles  70  may scatter white light and a colorant such as a dye or pigment in layer  104  may provide layer  24  with a desired color. For example, plasmonic nanoparticles  70  may include three different types of plasmonic nanoparticles or other suitable number of plasmonic nanoparticles to reflect white light, as described in connection with curves  92 ,  94 , and  96  of  FIG. 8  and a blue dye or pigment may be included in layer  104  to provide layers  24  with a desired blue color. 
       FIG. 12  shows how plasmonic nanoparticles  70  and colorant such as dye or pigment may be incorporated into structural layer  108 . In this configuration, structural layer  108  may be, for example, a polymer structure (e.g., a polymer substrate), plasmonic nanoparticles  70  may be embedded in some or all of the polymer of layer  108 , and colorant such as dye or pigment (e.g., non-black dye or pigment) may be incorporated into layer  108 . 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20170913
Publication Date: 20191210
Grant Date: 20191210
Priority Date: 20160921
Inventors: NORTHCOTT, MALCOLM J.
ZHANG, Arthur Y.
ZERCOE, BRADFORD J.
LAST, MATTHEW E.
GRAVES, JACK E.
PERALI, IRENE
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B2207/101", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B5/008", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B1/116", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/208", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/206", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B1/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01V8/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B1/115", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/281", "inventive": true, "first": false, "tree": "[]"}, {"code": "B22F1/0018", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/208", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B5/281", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B1/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B1/115", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01V8/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "B22F1/056", "inventive": true, "first": false, "tree": "[]"}, {"code": "B22F1/054", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B5/008", "inventive": true, "first": true, "tree": "[]"}, {"code": "B22F1/056", "inventive": true, "first": false, "tree": "[]"}, {"code": "B22F1/054", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B5/208", "inventive": true, "first": false, "tree": "[]"}, {"code": "B22F2007/042", "inventive": false, "first": false, "tree": "[]"}, {"code": "B22F7/08", "inventive": false, "first": false, "tree": "[]"}, {"code": "B22F2998/10", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 68766161