WO2025058752A1

WO2025058752A1 - Methods and apparatus for manufacturing a display apparatus

Info

Publication number: WO2025058752A1
Application number: PCT/US2024/041862
Authority: WO
Inventors: Songfeng HAN; Shasha LIU; Wei Qin; Jianyan Wang
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 2023-09-11
Filing date: 2024-08-12
Publication date: 2025-03-20
Anticipated expiration: 2026-03-11
Also published as: TW202532883A; KR20260060408A; CN121889720A

Abstract

A display apparatus includes a cover substrate including a first cover surface and an opposing second cover surface. A first anti-reflective coating is applied to the first cover surface. A light guide plate includes a first plate surface and an opposing second plate surface. The light guide plate includes a plurality of light extractors positioned at the second plate surface. A second anti-reflective coating is applied to the second plate surface and at least a portion of the plurality of light extractors. The display apparatus includes a third anti-reflective coating spaced a distance apart from the second anti-reflective coating such that a gap is between the second anti-reflective coating and the third anti-reflective coating. Methods of manufacturing a display apparatus are provided.

Description

A^TTORNEY D^OCKET N^O. SP23-207 METHODS AND APPARATUS FOR MANUFACTURING A DISPLAY APPARATUS CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Serial No.63/581742 filed on September 11, 2023, the content of which is relied upon and incorporated herein by reference in its entirety. FIELD [0002] The present disclosure relates generally to apparatus and methods for manufacturing a display apparatus and, more particularly, to methods for manufacturing a display apparatus comprising one or more anti-reflective coatings. BACKGROUND [0003] Glass sheets can be used in display applications, for example, liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light-emitting diode displays (OLEDs), and plasma display panels (PDPs). It is known to provide a display apparatus in display applications. However, display apparatuses can have an undesirable amount of internal light reflection. S^UMMARY [0004] The following presents a simplified summary of the disclosure to provide a basic understanding of some aspects described in the detailed description. [0005] In aspects, a display apparatus can comprise a cover substrate comprising a first cover surface and an opposing second cover surface. The display apparatus can comprise a first anti-reflective coating applied to the first cover surface. The first anti- reflective coating can comprise a total reflectivity within a range from about 1% to about 4% across a visible spectrum within a range from about 380 nanometers to about 750 nanometers. The display apparatus can comprise a light guide plate comprising a first plate surface and an opposing second plate surface. The first plate surface can face the second cover surface. The light guide plate can comprise a plurality of light extractors positioned at the second plate surface. The display apparatus can comprise a second anti-reflective coating applied to the second plate surface and at least a portion of the plurality of light extractors. The second anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 4% across the visible spectrum. The display apparatus can comprise a third anti-reflective coating spaced a distance apart from the second anti- reflective coating such that a gap is between the second anti-reflective coating and the third anti-reflective coating. The third anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 4% across the visible spectrum. [0006] In aspects, the display apparatus can comprise a polarizer and a color filter adjacent to the polarizer. A liquid crystal layer can be adjacent to the color filter. A reflector can be adjacent to the liquid crystal layer. A thin-film transistor substrate can be adjacent to the reflector. [0007] In aspects, the third anti-reflective coating can be applied to the polarizer. [0008] In aspects, the first anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 3% across the visible spectrum. The second anti- reflective coating can comprise a total reflectivity within a range from about 1% to about 3% across the visible spectrum. The third anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 3% across the visible spectrum. [0009] In aspects, the display apparatus can comprise an optically-clear adhesive attached to the second cover surface and the first plate surface such that that the cover substrate is attached to the light guide plate. [0010] In aspects, a fourth anti-reflective coating can be applied to the second cover surface. [0011] In aspects, the fourth anti-reflective coating can comprise a total reflectivity of less than about 2% across the visible spectrum. [0012] In aspects, a fifth anti-reflective coating can be applied to the first plate surface. [0013] In aspects, the fifth anti-reflective coating can comprise a total reflectivity of less than about 2% across the visible spectrum. [0014] In aspects, a display apparatus can comprise a cover substrate comprising a first cover surface and an opposing second cover surface. The display apparatus can comprise a first anti-reflective coating applied to the first cover surface. The first anti- reflective coating can comprise a total reflectivity within a range from about 1% to about 4% across a visible spectrum within a range from about 380 nanometers to about 750 nanometers. The display apparatus can comprise a light guide plate comprising a first plate surface and an opposing second plate surface. The light guide plate can comprise a plurality of light extractors positioned at the second plate surface. The display apparatus can comprise an optically-clear adhesive attached to the second cover surface and the first plate surface such that that the cover substrate is attached to the light guide plate. The display apparatus can comprise a second anti-reflective coating applied to the second plate surface and at least a portion of the plurality of light extractors. The second anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 4% across the visible spectrum. The display apparatus can comprise a third anti-reflective coating spaced a distance apart from the second anti-reflective coating such that a gap is between the second anti-reflective coating and the third anti-reflective coating. The third anti- reflective coating can be applied to a polarizer and comprising a total reflectivity within a range from about 1% to about 4% across the visible spectrum. [0015] In aspects, the display apparatus can comprise a color filter adjacent to the polarizer. A liquid crystal layer can be adjacent to the color filter. A reflector can be adjacent to the liquid crystal layer. A thin-film transistor substrate can be adjacent to the reflector. [0016] In aspects, the first anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 3% across the visible spectrum. The second anti- reflective coating can comprise a total reflectivity within a range from about 1% to about 3% across the visible spectrum. The third anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 3% across the visible spectrum. [0017] In aspects, methods of manufacturing a display apparatus can comprise applying a first anti-reflective coating to a first cover surface of a cover substrate. The first anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 4% across a visible spectrum within a range from about 380 nanometers to about 750 nanometers. Methods can comprise positioning a light guide plate adjacent to the cover substrate. The light guide plate can comprise a first plate surface and an opposing second plate surface. The first plate surface can face a second cover surface of the cover substrate. The light guide plate can comprise a plurality of light extractors positioned at the second plate surface. Methods can comprise applying a second anti-reflective coating to the second plate surface and at least a portion of the plurality of light extractors. The second anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 4% across the visible spectrum. Methods can comprise applying a third anti- reflective coating to a polarizer such that the third anti-reflective coating can be spaced a distance apart from the second anti-reflective coating and a gap can be between the second anti-reflective coating and the third anti-reflective coating. The third anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 4% across the visible spectrum. [0018] In aspects, methods can comprise attaching the second cover surface and the first plate surface with an optically-clear adhesive. [0019] In aspects, methods can comprise positioning a color filter adjacent to the polarizer. Methods can comprise positioning a liquid crystal layer adjacent to the color filter. Methods can comprise positioning a reflector adjacent to the liquid crystal layer. Methods can comprise positioning a thin-film transistor substrate adjacent to the reflector. [0020] In aspects, a direct reflection of ambient light from the display apparatus can be within a range from about 5% to about 7%. [0021] In aspects, the first anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 3% across the visible spectrum. The second anti- reflective coating can comprise a total reflectivity within a range from about 1% to about 3% across the visible spectrum. The third anti-reflective coating can comprise a total reflectivity within a range from about 1% to about 3% across the visible spectrum. [0022] In aspects, methods can comprise applying a fourth anti-reflective coating to the second cover surface, the fourth anti-reflective coating comprising a total reflectivity of less than about 2% across the visible spectrum. [0023] In aspects, methods can comprise applying a fifth anti-reflective coating to the first plate surface, the fifth anti-reflective coating comprising a total reflectivity of less than about 2% across the visible spectrum. [0024] Additional features and advantages of the aspects disclosed herein will be set forth in the detailed description that follows, and in part will be clear to those skilled in the art from that description or recognized by practicing the aspects described herein, including the detailed description which follows, the claims, as well as the appended drawings. It is to be understood that both the foregoing general description and the following detailed description present aspects intended to provide an overview or framework for understanding the nature and character of the aspects disclosed herein. The accompanying drawings are included to provide further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate various aspects of the disclosure, and together with the description explain the principles and operations thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0025] These and other features, aspects and advantages are better understood when the following detailed description is read with reference to the accompanying drawings, in which: [0026] FIG. 1 schematically illustrates an exemplary embodiment of a display apparatus comprising an anti-reflective coating in accordance with aspects of the disclosure; [0027] FIG. 2 schematically illustrates an exemplary embodiment of a display apparatus comprising additional anti-reflective coatings in accordance with aspects of the disclosure; and [0028] FIG. 3 schematically illustrates methods of manufacturing the display apparatus in accordance with aspects of the disclosure. D^ETAILED D^ESCRIPTION [0029] Aspects will now be described more fully hereinafter with reference to the accompanying drawings in which example aspects are shown. Whenever possible, the same reference numerals are used throughout the drawings to refer to the same or like parts. However, this disclosure may be embodied in many different forms and should not be construed as limited to the aspects set forth herein. [0030] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not, and need not be, exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. [0031] Ranges can be expressed herein as from “about” one value, and/or to “about” another value. When such a range is expressed, aspects include from the one value to the other value. Similarly, when values are expressed as approximations by use of the antecedent “about,” it will be understood that the value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. [0032] Directional terms as used herein - for example up, down, right, left, front, back, top, bottom, upper, lower, etc. - are made only with reference to the figures as drawn and are not intended to imply absolute orientation. [0033] Unless otherwise expressly stated, it is in no way intended that any methods set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus, specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred in any respect. This holds for any possible non-express basis for interpretation, including matters of logic relative to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of aspects described in the specification. [0034] As used herein, the singular forms "a," "an" and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise. [0035] The word “exemplary,” “example,” or various forms thereof are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” or as an “example” should not be construed as preferred or advantageous over other aspects or designs. Furthermore, examples are provided solely for purposes of clarity and understanding and are not meant to limit or restrict the disclosed subject matter or relevant portions of this disclosure in any manner. It can be appreciated that a myriad of additional or alternate examples of varying scope could have been presented but have been omitted for purposes of brevity. [0036] As used herein, the terms “comprising” and “including”, and variations thereof, shall be construed as synonymous and open-ended, unless otherwise indicated. A list of elements following the transitional phrases comprising or including is a non- exclusive list, such that elements in addition to those specifically recited in the list may also be present. [0037] The terms “substantial,” “substantially,” and variations thereof as used herein are intended to represent that a described feature is equal or approximately equal to a value or description. For example, a “substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, “substantially” is intended to denote that two values are equal or approximately equal. The term “substantially” may denote values within about 10% of each other, for example, within about 5% of each other, or within about 2% of each other. [0038] Modifications may be made to the instant disclosure without departing from the scope or spirit of the claimed subject matter. Unless specified otherwise, “first,” “second,” or the like are not intended to imply a temporal aspect, a spatial aspect, an ordering, etc. Rather, such terms are merely used as identifiers, names, etc. for features, elements, items, etc. For example, a first end and a second end generally correspond to end A and end B or two different ends. [0039] The present disclosure relates to a display apparatus and methods for manufacturing a display apparatus. Methods and apparatus for manufacturing a display apparatus will now be described by way of example aspects. FIG. 1 schematically illustrates a cross-sectional view of a display apparatus 101. The display apparatus 101 can comprise a cover substrate 103 comprising a first cover surface 105 and an opposing second cover surface 107. The first cover surface 105 and the second cover surface 107 face in opposite directions. In aspects, the cover substrate 103 can comprise a glass substrate, a glass-ceramic substrate, a plastic substrate, or another suitable substrate that may be rigid or flexible. The cover substrate 103 is optically transparent such that light can pass through the cover substrate 103 between the first cover surface 105 and the second cover surface 107. The cover substrate 103 can comprise a flat substrate or a curved substrate. [0040] The display apparatus 101 can comprise a first anti-reflective coating 111 applied to the cover substrate 103, for example, to the first cover surface 105. In this way, the first anti-reflective coating 111 may form an outermost layer of the display apparatus 101. In aspects, the first anti-reflective coating 111 can comprise a total reflectivity within a range from about 1% to about 4% across a visible spectrum of light (e.g., within a range from about 380 nanometers to about 750 nanometers), or within a range from about 1% to about 3% across the visible spectrum, or less than about 2% across the visible spectrum. As used herein, the term “visible spectrum” can refer to the portion of the electromagnetic spectrum that is visible to the human eye. The first anti-reflective coating 111 can be applied to the first cover surface 105, for example, by a discrete deposition process, continuous deposition process, physical vapor deposition, sputtering, etc. In aspects, the first anti-reflective coating 111 can comprise one or more layers of material. For example, when the first anti-reflective coating 111 comprises a plurality of layers, the first anti- reflective coating 111 may comprise alternating layers of differing refractive indices from one another, for example, alternating layers of low refractive index materials and high refractive index materials. For example, a first layer of the first anti-reflective coating 111 can comprise a low refractive index, and an adjacent second layer of the first anti-reflective coating 111 can comprise a high refractive index. In aspects, a difference in the refractive index of a low refractive index and a high refractive index may be greater than about 0.01, greater than about 0.05, greater than about 0.1, or greater than about 0.2. Accordingly, methods of manufacturing the display apparatus 101 can comprise applying (e.g., illustrated with arrowhead 301 in FIG. 3) the first anti-reflective coating 111 to the first cover surface 105 of the cover substrate 103. [0041] In aspects, the first anti-reflective coating 111 can comprise one or more of the following materials: SiO₂, Al₂O₃, GeO₂, SiO, AlO_xN_y, AlN, SiN_x, SiO_xN_y, Si_uAl_vO_xN_y, Ta₂O₅, Nb₂O₅, TiO₂, ZrO₂, TiN, MgO, MgF₂, BaF₂, CaF₂, SnO₂, HfO₂, Y₂O₃, MoO₃, DyF₃, YbF₃, YF₃, CeF₃, polymers, fluoropolymers, plasma-polymerized polymers, siloxane polymers, silsesquioxanes, polyimides, fluorinated polyimides, polyetherimide, polyethersulfone, polyphenylsulfone, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, acrylic polymers, urethane polymers, polymethylmethacrylate, etc.. In aspects, a low refractive index layer may comprise one or more of the following materials: SiO2, Al2O3, GeO2, SiO, AlOxNy, SiOxNy, SiuAlvOxNy, MgO, MgAl2O4, MgF2, BaF₂, CaF₂, DyF₃, YbF₃, YF₃, and CeF₃. In aspects, a high refractive index layer may comprise one or more of the following materials: Si_uAl_vO_xN_y, Ta₂O₅, Nb₂O₅, AlN, Si₃N₄, AlO_xN_y, SiO_xN_y, HfO₂, TiO₂, ZrO₂, Y₂O₃, Al₂O₃, MoO₃ and diamond-like carbon. In aspects, the nitrogen content of low refractive index layer materials may be minimized, and the oxygen content of high refractive index layer materials may be minimized. [0042] The display apparatus 101 can comprise an optically-clear adhesive 115 for attaching the cover substrate 103 to a light guide plate 121. For example, the optically- clear adhesive 115 can be attached to the second cover surface 107 and to a first plate surface 123 of the light guide plate 121, such that the cover substrate 103 can be attached to the light guide plate 121. In this way, methods can comprise attaching (e.g., illustrated with arrowhead 309 in FIG.3) the second cover surface 107 and the first plate surface 123 with the optically-clear adhesive 115. Due to the optically-clear adhesive 115 being bonded to the cover substrate 103 and the light guide plate 121, an air gap may not exist between the cover substrate 103 and the light guide plate 121. The optically-clear adhesive 115 can comprise one or more of a polyolefin, a polyamide, a halide-containing polymer (e.g., polyvinylchloride or a fluorine-containing polymer), an elastomer, a urethane, phenolic resin, parylene, polyethylene terephthalate (PET), polyether ether ketone (PEEK), or phenyl silicone. Example aspects of polyolefins include low molecular weight polyethylene (LDPE), high molecular weight polyethylene (HDPE), ultrahigh molecular weight polyethylene (UHMWPE), and polypropylene (PP). Example aspects of fluorine- containing polymers include polytetrafluoroethylene (PTFE), polyvinylfluoride (PVF), polyvinylidene fluoride (PVDF), perfluoropolyether (PFPE), perfluorosulfonic acid (PFSA), a perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP) polymers, and ethylene tetrafluoro ethylene (ETFE) polymers. Example aspects of elastomers include rubbers (e.g., polybutadiene, polyisoprene, chloroprene rubber, butyl rubber, nitrile rubber) and block copolymers (e.g., styrene-butadiene, high-impact polystyrene, poly(dichlorophosphazene). The optically-clear adhesive 115 can comprise one or more optically transparent polymers: an acrylic (e.g., polymethylmethacrylate (PMMA)), an epoxy, silicone, and/or a polyurethane. Exemplary aspects of epoxies include bisphenol- based epoxy resins, novolac-based epoxies, cycloaliphatic-based epoxies, and glycidylamine-based epoxies. In even further aspects, the optically-clear adhesive 115 can comprise, but is not limited to, acrylic adhesives, for example, 3M 8212 adhesive, or an optically transparent liquid adhesive, for example, a LOCTITE optically transparent liquid adhesive. Example aspects of optically clear adhesives comprise transparent acrylics, epoxies, silicones, and polyurethanes. For example, the optically transparent liquid adhesive could comprise one or more of LOCTITE AD 8650, LOCTITE AA 3922, LOCTITE EA E-05MR, LOCTITE UK U-09LV, which are all available from Henkel. [0043] The display apparatus 101 comprises the light guide plate 121, which comprises the first plate surface 123 and an opposing second plate surface 125. The first plate surface 123 and the second plate surface 125 face in opposite directions, with the first plate surface 123 facing the second cover surface 107 of the cover substrate 103. Methods can comprise positioning (e.g., illustrated with arrowhead 303 in FIG. 3) the light guide plate 121 adjacent to the cover substrate 103. The light guide plate 121 comprises a transparent material used for lighting and display applications. As used herein, the term “transparent” is intended to denote that the light guide plate 121 comprises an optical transmission of greater than about 70 percent over a length of about 500 millimeters in the visible region of the spectrum (e.g., about 380-750 nanometers). In aspects, the light guide plate 121 may comprise an optical transmission of greater than about 50 percent in the ultraviolet (UV) region (about 100-400 nanometers) over a length of 500 millimeters. In aspects, the light guide plate 121 may comprise an optical transmission of at least 95 percent over a path length of 50 millimeters for wavelengths ranging from about 450 nanometers to about 650 nanometers. In aspects, transmission data in the visible spectrum can be measured with a Lambda 950 UV/Vis/NIR Spectrophotometer manufactured by PerkinElmer Inc. (Waltham, Massachusetts USA). In aspects, the Lambda 950 apparatus can be fitted with a 150 mm integrating sphere. Data can be collected using an open beam baseline and a Spectralon^® reference reflectance disk. [0044] The light guide plate 121 may comprise a refractive index within a range from about 1.3 to about 1.8. In other aspects, the light guide plate 121 may have a relatively low level of light attenuation (e.g., due to absorption and/or scattering). The light attenuation (a) of the light guide plate 121 may, for example, be less than about 5 decibels per meter for wavelengths ranging from about 380-750 nanometers, and can be determined via testing or based on the material and dimensions of the light guide plate 121. The light guide plate 121 may comprise a wide range of materials that provide desired optical properties. In aspects, the light guide plate 121 can comprise an amorphous inorganic material (e.g., glass), a crystalline material (e.g., sapphire, single crystal or polycrystalline alumina, spinel (MgAl2O4), quartz), or a polymer. Examples of suitable polymers include, without limitation, the following as well as copolymers and blends thereof: thermoplastics including polystyrene (PS), polycarbonate (PC), polyesters including polyethyleneterephthalate (PET), polyolefins including polyethylene (PE), polyvinylchloride (PVC), acrylic polymers including polymethyl methacrylate (PMMA), thermoplastic urethanes (TPU), polyetherimide (PEI), epoxies, and silicones including polydimethylsiloxane (PDMS). Examples of glass, which may be strengthened or non- strengthened and may be free of lithia or not, include soda lime glass, alkali aluminosilicate glass, alkali containing borosilicate glass and alkali aluminoborosilicate glass. As used herein, the term "strengthened” when applied to a substrate, for example glass or another transparent layer, may refer to a substrate that has been chemically strengthened, for example through ion-exchange of larger ions for smaller ions in the surface of the substrate. However, other strengthening methods known in the art, for example thermal tempering, or utilizing a mismatch of the coefficient of thermal expansion between portions of the substrate to create compressive stress and central tension regions, may be utilized to form strengthened substrates. Non-limiting examples of commercially available glasses suitable for use as the glass light guide plate 121 comprise EAGLE XG®, Lotus, Willow®, Iris™, and Gorilla® glasses from Corning Incorporated. [0045] The light guide plate 121 can comprise a plurality of light extractors 129 positioned at the second plate surface 125. In aspects, the plurality of light extractors 129 may comprise a rounded or curved shape that projects outwardly from the second plate surface 125. For example, the plurality of light extractors 129 can comprise a first light extractor 133, a second light extractor 135, etc. The second plate surface 125 can comprise a first surface portion 137, a second surface portion 139, etc. In aspects, the light extractors 133, 135 can be spaced apart and separated by surface portions 137, 139. For example, the first surface portion 137 can be positioned between the first light extractor 133 and the second light extractor 135. The second light extractor 135 can be positioned between the first surface portion 137 and the second surface portion 139. In this way, the light extractors 133, 135 and the surface portions 137, 139 can alternate positions along the second plate surface 125. In aspects, the plurality of light extractors 129 are not limited to the illustrated circular, round shape. Rather, in aspects, some or all of the plurality of light extractors 129 can comprise other shapes, for example, a quadrilateral shape (e.g., a rectangular shape, a square shape, etc.), a hexagonal shape, etc. [0046] In aspects, some or all of the plurality of light extractors 129 can comprise diffuse reflectors that can enhance the scattering of light rays at high enough angles such that the light rays can propagate in the light guide plate 121 by total internal reflection. In other aspects, some or all of the plurality of light extractors 129 can comprise specular reflectors, in which a mirror-like reflection of light is provided and incident light is reflected into a single outgoing direction. The plurality of light extractors 129 can be formed by printing e.g., inkjet printing, screen printing, microprinting), a pattern with white ink, black ink, metallic ink, or other suitable ink. The plurality of light extractors 129 may also be formed by first depositing a continuous layer of white or metallic material (e.g., by physical vapor deposition or any number of coating techniques, such as, for example, slot die, or spray coating), and then patterning the layer by photolithography or other known methods of area-selective material removal. [0047] The display apparatus 101 can comprise a second anti-reflective coating 143 applied to the second plate surface 125 and at least a portion of the plurality of light extractors 129. For example, in aspects, the second anti-reflective coating 143 may cover some or all of the second plate surface 125 (e.g., some or all of the surface portions 137, 139, etc.) and may cover some or all of the plurality of light extractors 129 (e.g., the light extractors 133, 135, etc.). In this way, the second anti-reflective coating 143 can at least partially cover a side of the light guide plate 121. In aspects, the second anti-reflective coating 143 may comprise the same material as, or a different material than, the first anti- reflective coating 111. In aspects, the second anti-reflective coating 143 can comprise a total reflectivity within a range from about 1% to about 4% across a visible spectrum, or within a range from about 1% to about 3% across the visible spectrum, or less than about 2% across the visible spectrum. In aspects, the total reflectivity can be measured by shining light on a material (e.g., the anti-reflective coating, for example) and measuring the light reflected from the material, wherein the reflected light may comprise specular reflected light and diffuse reflected light. Together, the specular reflected light and the diffuse reflected light can be combined and referred to as total reflected light, or total reflectivity of the material. In aspects, relative specular reflectance can be measured with a specular reflectance measurement attachment. In aspects, relative diffuse reflectance can be measured by using an integrating sphere to measure the diffuse reflected light with specular reflected light excluded. In addition, or in the alternative, relative total reflectance can be measured using an integrating sphere, wherein light can shine on the material at an incident angle (e.g., less than about 10 degrees, for example), and then using an integrating sphere to measure both the diffuse reflected light and the specular reflected light from the material. [0048] The second anti-reflective coating 143 can be applied to the second plate surface 125, for example, by a discrete deposition process, continuous deposition process, physical vapor deposition, sputtering, etc. Methods can comprise applying (e.g., illustrated with arrowhead 305 in FIG. 3) the second anti-reflective coating 143 to the second plate surface 125 and at least a portion of the plurality of light extractors 129. In aspects, the second anti-reflective coating 143 can be applied before or after the formation of the plurality of light extractors 129. For example, in aspects, the second anti-reflective coating 143 can first be applied to the second plate surface 125, followed by the formation of the plurality of light extractors 129 via etching, puncturing, and/or laser-printing of the plurality of light extractors 129 onto the second plate surface 125. In the alternative, the plurality of light extractors 129 can be formed first, followed by the application of the second anti-reflective coating 143 to the second plate surface 125. In aspects, the second anti-reflective coating 143 can cover all of the second plate surface 125 and all of the plurality of light extractors 129. [0049] In aspects, the second anti-reflective coating 143 can comprise one or more layers of material. For example, when the second anti-reflective coating 143 comprises a plurality of layers, the second anti-reflective coating 143 may comprise alternating layers of differing refractive indices from one another, for example, alternating layers of low refractive index materials and high refractive index materials. For example, a first layer of the second anti-reflective coating 143 can comprise a low refractive index, and an adjacent second layer of the second anti-reflective coating 143 can comprise a high refractive index. In aspects, a difference in the refractive index of a low refractive index and a high refractive index may be greater than about 0.01, greater than about 0.05, greater than about 0.1, or greater than about 0.2. [0050] In aspects, the second anti-reflective coating 143 can comprise one or more of the following materials: SiO2, Al2O3, GeO2, SiO, AlOxNy, AlN, SiNx, SiOxNy, SiuAlvOxNy, Ta2O5, Nb2O5, TiO2, ZrO2, TiN, MgO, MgF2, BaF2, CaF2, SnO2, HfO2, Y2O3, MoO3, DyF3, YbF3, YF3, CeF3, polymers, fluoropolymers, plasma-polymerized polymers, siloxane polymers, silsesquioxanes, polyimides, fluorinated polyimides, polyetherimide, polyethersulfone, polyphenylsulfone, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, acrylic polymers, urethane polymers, polymethylmethacrylate, etc.. In aspects, a low refractive index layer may comprise one or more of the following materials: SiO2, Al2O3, GeO2, SiO, AlOxNy, SiOxNy, SiuAlvOxNy, MgO, MgAl2O4, MgF2, BaF2, CaF2, DyF3, YbF3, YF3, and CeF3. In aspects, a high refractive index layer may comprise one or more of the following materials: SiuAlvOxNy, Ta2O5, Nb2O5, AlN, Si3N4, AlOxNy, SiOxNy, HfO2, TiO2, ZrO2, Y2O3, Al2O3, MoO3 and diamond-like carbon. In aspects, the nitrogen content of low refractive index layer materials may be minimized, and the oxygen content of high refractive index layer materials may be minimized. [0051] The display apparatus 101 can comprise a third anti-reflective coating 147 applied to a polarizer 149, with the third anti-reflective coating 147 spaced a distance apart from the second anti-reflective coating 143 such that a gap 151 is formed between the second anti-reflective coating 143 and the third anti-reflective coating 147. The polarizer 149 can comprise a first polarizer surface 155 and an opposing second polarizer surface 157 that can face in opposite directions, with the first polarizer surface 155 facing the light guide plate 121. In aspects, the third anti-reflective coating 147 is applied to the first polarizer surface 155, with the third anti-reflective coating 147 covering some, or all, of the first polarizer surface 155. The third anti-reflective coating 147 may comprise the same material as, or a different material than, the first anti-reflective coating 111 and/or the second anti-reflective coating 143. In this way, the third anti-reflective coating 147 can comprise a total reflectivity within a range from about 1% to about 4% across a visible spectrum, or within a range from about 1% to about 3% across the visible spectrum, or less than about 2% across the visible spectrum. The gap 151 between the second anti-reflective coating 143 and the third anti-reflective coating 147 can comprise an empty void or space (e.g., an air gap), such that the second anti-reflective coating 143 may not be in contact with the third anti-reflective coating 147. [0052] The third anti-reflective coating 147 can be applied to the polarizer 149, for example, by a discrete deposition process, continuous deposition process, physical vapor deposition, sputtering, etc. Methods can comprise applying (e.g., illustrated with arrowhead 307 in FIG. 3) the third anti-reflective coating 147 to the polarizer 149 such that the third anti-reflective coating 147 is spaced a distance apart from the second anti- reflective coating 143 and the gap 151 is between the second anti-reflective coating 143 and the third anti-reflective coating 147. In aspects, the third anti-reflective coating 147 can comprise one or more layers of material. For example, when the third anti-reflective coating 147 comprises a plurality of layers, the third anti-reflective coating 147 may comprise alternating layers of differing refractive indices from one another, for example, alternating layers of low refractive index materials and high refractive index materials. For example, a first layer of the third anti-reflective coating 147 can comprise a low refractive index, and an adjacent second layer of the third anti-reflective coating 147 can comprise a high refractive index. In aspects, a difference in the refractive index of a low refractive index and a high refractive index may be greater than about 0.01, greater than about 0.05, greater than about 0.1, or greater than about 0.2. [0053] In aspects, the third anti-reflective coating 147 can comprise one or more of the following materials: SiO2, Al2O3, GeO2, SiO, AlOxNy, AlN, SiNx, SiOxNy, SiuAlvOxNy, Ta2O5, Nb2O5, TiO2, ZrO2, TiN, MgO, MgF2, BaF2, CaF2, SnO2, HfO2, Y2O3, MoO3, DyF3, YbF₃, YF₃, CeF₃, polymers, fluoropolymers, plasma-polymerized polymers, siloxane polymers, silsesquioxanes, polyimides, fluorinated polyimides, polyetherimide, polyethersulfone, polyphenylsulfone, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, acrylic polymers, urethane polymers, polymethylmethacrylate, etc.. In aspects, a low refractive index layer may comprise one or more of the following materials: SiO2, Al2O3, GeO2, SiO, AlOxNy, SiOxNy, SiuAlvOxNy, MgO, MgAl2O4, MgF2, BaF2, CaF2, DyF3, YbF3, YF3, and CeF3. In aspects, a high refractive index layer may comprise one or more of the following materials: SiuAlvOxNy, Ta2O5, Nb2O5, AlN, Si3N4, AlO_xN_y, SiO_xN_y, HfO₂, TiO₂, ZrO₂, Y₂O₃, Al₂O₃, MoO₃ and diamond-like carbon. In aspects, the nitrogen content of low refractive index layer materials may be minimized, and the oxygen content of high refractive index layer materials may be minimized. [0054] The polarizer 149 comprises an optical filter that allows light waves of a specific polarization to pass through the polarizer 149 while blocking light waves of other polarizations. In this way, the polarizer 149 can filter out one or more specific polarizations (e.g., to limit specific polarizations from passing through the polarizer 149). The display apparatus 101 can comprise a color filter 161 extending adjacent to the polarizer 149 and attached to the second polarizer surface 157. The color filter 161 can comprise an array of red, green, and/or blue filters to produce a desired display color. Methods can comprise positioning (e.g., illustrated with arrowhead 311 in FIG.3) the color filter 161 adjacent to the polarizer 149. The display apparatus 101 can comprise a liquid crystal layer 165 extending adjacent to the color filter 161. Methods can comprise positioning (e.g., illustrated with arrowhead 313 in FIG.3) the liquid crystal layer 165 adjacent to the color filter 161. The display apparatus 101 can comprise a reflector 171 extending adjacent to the liquid crystal layer 165. The reflector 171 comprises a material that is inherently reflective, such as, for example, aluminum, steel, silver, etc. In aspects, the reflector 171 can comprise a material such as polyethyleneterephthalate (PET) or polycarbonate (PC) that is reflective when placed adjacent to another material in the display apparatus 101 having a different refractive index. In aspects, the reflector 171 may comprise an average reflectance over a wavelength range from about 400 nm to about 700 nm of about 90% or more, about 95% or more, about 96% or more, or about 98% or more. In aspects, the reflector 171 can face the liquid crystal layer 165. Methods can comprise positioning (e.g., illustrated with arrowhead 315 in FIG. 3) the reflector 171 adjacent to the liquid crystal layer 165. The display apparatus 101 can comprise a thin-film transistor (TFT) substrate 175 extending adjacent to the reflector 171. Methods can comprise positioning (e.g., illustrated with arrowhead 317 in FIG.3) the thin-film transistor substrate 175 adjacent to the reflector 171. [0055] The display apparatus 101 can comprise a light source 181 that can deliver light into a first edge 183 of the light guide plate 121. The display apparatus 101 can therefore comprise front-lit reflective display apparatus. The first edge 183 can extend along a perimeter of the light guide plate 121 between the first plate surface 123 and the second plate surface 125. In aspects, the light source 181 can comprise one or more light- emitting diodes (LEDs) positioned along the first edge 183. In aspects, the light source 181 can comprise a thickness or height that may be less than or equal to the thickness of the light guide plate 121. While FIG.1 illustrates a single edge 183 being injected by light from the light source 181, additional light sources (e.g., which may be similar or identical to the light source 181) may be positioned along other edges of the light guide plate 121. In aspects, the light source 181 can be coupled to the first edge 183, for example, by being positioned adjacent to, and/or by being attached to, the first edge 183. In aspects, none, some, or all of the other edges of the light guide plate 121 may comprise an edge reflector that can reflect substantially all of the light impinging thereon. In this way, the edge reflectors can reflect a certain percentage of light. Exemplary percentages of reflection can be greater than about 50%, between about 50% to about 95%, less than or equal to 100%, etc. [0056] The light source 181 can supply (e.g., inject, direct, etc.) light into the light guide plate 121 from a side (e.g., adjacent to the first edge 183) of the light guide plate 121. The light guide plate 121 can receive the light from the light source 181, and redirect the light to create uniform illumination for the reflective liquid crystal layer 165. The plurality of light extractors 129 can extract the light from the light source 181 and limit the likelihood of the light becoming trapped within the light guide plate 121 due to total internal reflection. [0057] FIG. 2 illustrates additional aspects of the display apparatus 101, further comprising additional anti-reflective coatings. For example, the display apparatus 101 can comprise a fourth anti-reflective coating 201 applied to the second cover surface 107 of the cover substrate 103. The fourth anti-reflective coating 201 can be positioned between, and in contact with, the cover substrate 103 and the optically-clear adhesive 115, with the optically-clear adhesive 115 bonded to the fourth anti-reflective coating 201. The fourth anti-reflective coating 201 can comprise a total reflectivity within a range from about 1% to about 4% across a visible spectrum, or within a range from about 1% to about 3% across the visible spectrum, or less than about 2% across the visible spectrum. The fourth anti- reflective coating 201 can be applied, for example, by a discrete deposition process, continuous deposition process, physical vapor deposition, sputtering, etc. Methods can comprise applying (e.g., illustrated with arrowhead 319 in FIG.3) the fourth anti-reflective coating 201 to the second cover surface 107. In aspects, the fourth anti-reflective coating 201 can comprise one or more layers of material. For example, when the fourth anti- reflective coating 201 comprises a plurality of layers, the fourth anti-reflective coating 201 may comprise alternating layers of differing refractive indices from one another, for example, alternating layers of low refractive index materials and high refractive index materials. For example, a first layer of the fourth anti-reflective coating 201 can comprise a low refractive index, and an adjacent second layer of the fourth anti-reflective coating 201 can comprise a high refractive index. In aspects, a difference in the refractive index of a low refractive index and a high refractive index may be greater than about 0.01, greater than about 0.05, greater than about 0.1, or greater than about 0.2. [0058] In aspects, the fourth anti-reflective coating 201 can comprise one or more of the following materials: SiO2, Al2O3, GeO2, SiO, AlOxNy, AlN, SiNx, SiOxNy,

MoO₃, DyF₃, YbF₃, YF₃, CeF₃, polymers, fluoropolymers, plasma-polymerized polymers, siloxane polymers, silsesquioxanes, polyimides, fluorinated polyimides, polyetherimide, polyethersulfone, polyphenylsulfone, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, acrylic polymers, urethane polymers, polymethylmethacrylate, etc.. In aspects, a low refractive index layer may comprise one or more of the following materials: SiO2, Al2O3, GeO2, SiO, AlOxNy, SiOxNy, SiuAlvOxNy, MgO, MgAl2O4, MgF2, BaF2, CaF2, DyF3, YbF3, YF3, and CeF3. In aspects, a high refractive index layer may comprise one or more of the following materials: Si_uAl_vO_xN_y, Ta₂O₅, Nb₂O₅, AlN, Si₃N₄, AlO_xN_y, SiO_xN_y, HfO₂, TiO₂, ZrO₂, Y₂O₃, Al₂O₃, MoO₃ and diamond-like carbon. In aspects, the nitrogen content of low refractive index layer materials may be minimized, and the oxygen content of high refractive index layer materials may be minimized. [0059] In aspects, the display apparatus 101 can comprise a fifth anti-reflective coating 203 applied to the first plate surface 123 of the light guide plate 121. The fifth anti-reflective coating 203 can be positioned between, and in contact with, the light guide plate 121 and the optically-clear adhesive 115, with the optically-clear adhesive 115 bonded to the fifth anti-reflective coating 203. The fifth anti-reflective coating 203 can comprise a total reflectivity within a range from about 1% to about 4% across a visible spectrum, or within a range from about 1% to about 3% across the visible spectrum, or less than about 2% across the visible spectrum. The fifth anti-reflective coating 203 can be applied, for example, by a discrete deposition process, continuous deposition process, physical vapor deposition, sputtering, etc. Methods can comprise applying (e.g., illustrated with arrowhead 321 in FIG.3) the fifth anti-reflective coating 203 to the first plate surface 123. In aspects, the fifth anti-reflective coating 203 can comprise one or more layers of material. For example, when the fifth anti-reflective coating 203 comprises a plurality of layers, the fifth anti-reflective coating 203 may comprise alternating layers of differing refractive indices from one another, for example, alternating layers of low refractive index materials and high refractive index materials. For example, a first layer of the fifth anti- reflective coating 203 can comprise a low refractive index, and an adjacent second layer of the fifth anti-reflective coating 203 can comprise a high refractive index. In aspects, a difference in the refractive index of a low refractive index and a high refractive index may be greater than about 0.01, greater than about 0.05, greater than about 0.1, or greater than about 0.2. [0060] In aspects, the fifth anti-reflective coating 203 can comprise one or more of the following materials: SiO2, Al2O3, GeO2, SiO, AlOxNy, AlN, SiNx, SiOxNy, SiuAlvOxNy, Ta2O5, Nb2O5, TiO2, ZrO2, TiN, MgO, MgF2, BaF2, CaF2, SnO2, HfO2, Y2O3, MoO3, DyF3, YbF3, YF3, CeF3, polymers, fluoropolymers, plasma-polymerized polymers, siloxane polymers, silsesquioxanes, polyimides, fluorinated polyimides, polyetherimide, polyethersulfone, polyphenylsulfone, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, acrylic polymers, urethane polymers, polymethylmethacrylate, etc.. In aspects, a low refractive index layer may comprise one or more of the following materials: SiO₂, Al₂O₃, GeO₂, SiO, AlO_xN_y, SiO_xN_y, Si_uAl_vO_xN_y, MgO, MgAl₂O₄, MgF₂, BaF₂, CaF₂, DyF₃, YbF₃, YF₃, and CeF₃. In aspects, a high refractive index layer may comprise one or more of the following materials: SiuAlvOxNy, Ta2O5, Nb2O5, AlN, Si3N4, AlOxNy, SiOxNy, HfO2, TiO2, ZrO2, Y2O3, Al2O3, MoO3 and diamond-like carbon. In aspects, the nitrogen content of low refractive index layer materials may be minimized, and the oxygen content of high refractive index layer materials may be minimized. [0061] The display apparatus 101 illustrated and described herein provides several benefits. For example, the anti-reflective coatings 111, 143, 147, 201, 203 can reduce direct reflection. For example, in aspects, direct reflection of ambient light from the display apparatus 101 may be within a range from about 5% to about 7%. That is, in an example, when the display apparatus 101 comprises the three anti-reflective coatings 111, 143, 147, the display apparatus 101 may comprise a direct reflection of ambient light of about 6% and light transmission of about 94.1%. In contrast, for a display apparatus without any anti-reflective coatings, a direct reflection of ambient light is about 12% and transmission is about 88%. The anti-reflective coatings 143, 147 applied to the light guide plate 121 and the polarizer 149 can further reduce Fresnel reflection by about 50% or more, as compared to a display apparatus without an anti-reflective coating applied to a light guide plate and polarizer. Fresnel reflection refers to when light reaches an interface between two different and transparent media, that a portion of the light is transmitted into the other material while another portion of the light is reflected back into the original material. Further, the anti-reflective coatings 111, 143, 147, 201, 203 can increase the contrast ratio as compared to a display apparatus without an anti-reflective coating. [0062] It should be understood that while various aspects have been described in detail relative to certain illustrative and specific examples thereof, the present disclosure should not be considered limited to such, as numerous modifications and combinations of the disclosed features are possible without departing from the scope of the following claims.

Claims

What is claimed is: 1. A display apparatus comprising: a cover substrate comprising a first cover surface and an opposing second cover surface; a first anti-reflective coating applied to the first cover surface, the first anti- reflective coating comprising a total reflectivity within a range from about 1% to about 4% across a visible spectrum within a range from about 380 nanometers to about 750 nanometers; a light guide plate comprising a first plate surface and an opposing second plate surface, the first plate surface facing the second cover surface, the light guide plate comprising a plurality of light extractors positioned at the second plate surface; a second anti-reflective coating applied to the second plate surface and at least a portion of the plurality of light extractors, the second anti-reflective coating comprising a total reflectivity within a range from about 1% to about 4% across the visible spectrum; and a third anti-reflective coating spaced a distance apart from the second anti- reflective coating such that a gap is between the second anti-reflective coating and the third anti-reflective coating, the third anti-reflective coating comprising a total reflectivity within a range from about 1% to about 4% across the visible spectrum.

2. The display apparatus of claim 1, further comprising: a polarizer; a color filter adjacent to the polarizer; a liquid crystal layer adjacent to the color filter; a reflector adjacent to the liquid crystal layer; and a thin-film transistor substrate adjacent to the reflector.

3. The display apparatus of claim 2, wherein the third anti-reflective coating is applied to the polarizer.

4. The display apparatus of any one of claims 1-3, wherein one or more of: the first anti-reflective coating comprises a total reflectivity within a range from about 1% to about 3% across the visible spectrum; the second anti-reflective coating comprises a total reflectivity within a range from about 1% to about 3% across the visible spectrum; or the third anti-reflective coating comprises a total reflectivity within a range from about 1% to about 3% across the visible spectrum.

5. The display apparatus of any one of claims 1-4, further comprising an optically- clear adhesive attached to the second cover surface and the first plate surface such that that the cover substrate is attached to the light guide plate.

6. The display apparatus of any one of claims 1-4, further comprising a fourth anti- reflective coating applied to the second cover surface.

7. The display apparatus of claim 6, wherein the fourth anti-reflective coating comprises a total reflectivity of less than about 2% across the visible spectrum.

8. The display apparatus of any one of claims 6-7, further comprising a fifth anti- reflective coating applied to the first plate surface.

9. The display apparatus of claim 8, wherein the fifth anti-reflective coating comprises a total reflectivity of less than about 2% across the visible spectrum.

10. A display apparatus comprising: a cover substrate comprising a first cover surface and an opposing second cover surface; a first anti-reflective coating applied to the first cover surface, the first anti- reflective coating comprising a total reflectivity within a range from about 1% to about 4% across a visible spectrum within a range from about 380 nanometers to about 750 nanometers; a light guide plate comprising a first plate surface and an opposing second plate surface, the light guide plate comprising a plurality of light extractors positioned at the second plate surface; an optically-clear adhesive attached to the second cover surface and the first plate surface such that the cover substrate is attached to the light guide plate; a second anti-reflective coating applied to the second plate surface and at least a portion of the plurality of light extractors, the second anti-reflective coating comprising a total reflectivity within a range from about 1% to about 4% across the visible spectrum; and a third anti-reflective coating spaced a distance apart from the second anti- reflective coating such that a gap is between the second anti-reflective coating and the third anti-reflective coating, the third anti-reflective coating applied to a polarizer and comprising a total reflectivity within a range from about 1% to about 4% across the visible spectrum.

11. The display apparatus of claim 10, further comprising: a color filter adjacent to the polarizer; a liquid crystal layer adjacent to the color filter; a reflector adjacent to the liquid crystal layer; and a thin-film transistor substrate adjacent to the reflector.

12. The display apparatus of claim 11, wherein one or more of: the first anti-reflective coating comprises a total reflectivity within a range from about 1% to about 3% across the visible spectrum; the second anti-reflective coating comprises a total reflectivity within a range from about 1% to about 3% across the visible spectrum; or the third anti-reflective coating comprises a total reflectivity within a range from about 1% to about 3% across the visible spectrum.

13. A method of manufacturing a display apparatus comprising: applying a first anti-reflective coating to a first cover surface of a cover substrate, the first anti-reflective coating comprising a total reflectivity within a range from about 1% to about 4% across a visible spectrum within a range from about 380 nanometers to about 750 nanometers; positioning a light guide plate adjacent to the cover substrate, the light guide plate comprising a first plate surface and an opposing second plate surface, the first plate surface facing a second cover surface of the cover substrate, the light guide plate comprising a plurality of light extractors positioned at the second plate surface; applying a second anti-reflective coating to the second plate surface and at least a portion of the plurality of light extractors, the second anti-reflective coating comprising a total reflectivity within a range from about 1% to about 4% across the visible spectrum; and applying a third anti-reflective coating to a polarizer such that the third anti- reflective coating is spaced a distance apart from the second anti-reflective coating and a gap is between the second anti-reflective coating and the third anti-reflective coating, the third anti-reflective coating comprising a total reflectivity within a range from about 1% to about 4% across the visible spectrum.

14. The method of claim 13, further comprising attaching the second cover surface and the first plate surface with an optically-clear adhesive.

15. The method of any one of claims 13-14, further comprising: positioning a color filter adjacent to the polarizer; positioning a liquid crystal layer adjacent to the color filter; positioning a reflector adjacent to the liquid crystal layer; and positioning a thin-film transistor substrate adjacent to the reflector.

16. The method of claim 15, wherein a direct reflection of ambient light from the display apparatus is within a range from about 5% to about 7%.

17. The method of any one of claims 13-16, wherein one or more of: the first anti-reflective coating comprises a total reflectivity within a range from about 1% to about 3% across the visible spectrum; the second anti-reflective coating comprises a total reflectivity within a range from about 1% to about 3% across the visible spectrum; or the third anti-reflective coating comprises a total reflectivity within a range from about 1% to about 3% across the visible spectrum.

18. The method of any one of claims 13-17, further comprising applying a fourth anti- reflective coating to the second cover surface, the fourth anti-reflective coating comprising a total reflectivity of less than about 2% across the visible spectrum.

19. The method of any one of claims 13-18, further comprising applying a fifth anti- reflective coating to the first plate surface, the fifth anti-reflective coating comprising a total reflectivity of less than about 2% across the visible spectrum.