WO2020146320A1

WO2020146320A1 - Antireflective overlays for mobile devices and methods of forming the same

Info

Publication number: WO2020146320A1
Application number: PCT/US2020/012495
Authority: WO
Inventors: Phong Ngo
Original assignee: General Plasma Inc.
Priority date: 2019-01-11
Filing date: 2020-01-07
Publication date: 2020-07-16

Abstract

Antireflective overlays and methods of forming the same are described. In embodiments the antireflective overlays are for mobile devices such as mobile phones, and include a base structure including a glass substrate with a first side and a second side opposing the first side. An antireflective stack including a plurality of layers of differing refractive index is present on the first side of the glass substrate. The antireflective overlay may exhibit a reflectance of less than or equal to about 3% in wavelength range of 425 nanometers (nm) to 675 nm.

Description

ANTIREFLECTIVE OVERLAYS FOR MOBILE DEVICES AND METHODS OF FORMING

THE SAME

BY: PHONG NGO

FIELD

[0001] The present disclosure generally relates to antireflective overlays for mobile devices and methods of forming the same. In particular, the present disclosure relates to antireflective glass overlays for mobile devices and/or components thereof, such as displays, visible light emitting/receiving components, and infrared light emitting/receiving components.

BACKGROUND

[0002] Electronic devices such as computer monitors, smart phones, tablet computers, laptops, etc. include a display for conveying information to a user. Such displays include a cover layer (e.g., of glass or another material) for protection of underlying device components, and to provide an interface (e.g., touch screen) through which a user may interact. Such cover layers can reflect a significant amount of incident light when the device is used outdoors or in another highly illuminated environment. Uncoated glass, for example, has refractive index of 1.52 and can reflect more than 4.5% of incident light in the visible spectrum ranging from 400 nanometers (nm) to 700 nm. This can make it challenging for a user of a device with an uncoated glass cover layer to view content on the device in high ambient lighting conditions. The high reflectance of uncoated glass can also undesirably reduce the color contrast of the display. [0003] An antireflective (AR) coating directly on the cover layer of a mobile display can effectively address the above noted problems, but is rarely used in mobile device applications due to previously unsolved challenges related to durability, environmental stability and optical performance specifications. For example, smart phones are frequently stowed in pockets or purses where the display cover layer is rubbed and scratched by keys and other objects. They are also often utilized in hot and humid environments. Frequent handling of such devices can also result in the deposition of oils and personal cosmetic products on the display. Consequently, AR coatings for mobile devices may need to meet challenging product specifications. An AR coating for a mobile device application also needs to be amenable to high volume, high yield mass production to be commercially viable.

[0004] An alternative to depositing an AR coating directly on an integral cover layer of a display is to apply an antireflective overlay to the integral cover layer, e.g., as a“screen protector.” Such screen protectors are often after-market products applied by a consumer to the cover layer using an adhesive that is optically matched to reduce reflections on the cover layer, so that a higher reflectance surface becomes the air contacting surface of the overlay. For instance, an overlay made of polyethylene terephthalate may reflect 4.4% of ambient light in high ambient light conditions. However, an AR coating for such an overlay will be subject to the same environmental stresses as an AR coated cover layer, and thus needs to meet the same challenging durability, environmental and optical performance requirements as above. Meeting those requirements can be challenging, particularly when an overlay including a plastic substrate is used. This is because plastic is generally softer than glass (the substrate for an AR coated cover layer), and because the hygroscopic nature of plastic can hinder the adhesion of an AR coating thereto.

[0005] Glass overlays are becoming increasingly popular as a high durability option for protecting electronic displays, and particularly for protecting smart phone displays. Although current glass overlays are useful and can provide significant protection, many glass overlays are formed from uncoated glass and thus may reflect a significant amount of incident light for the same reasons discussed above.

[0006] Many glass overlays are adhered to the (glass) surface of a smart phone or other device using an adhesive assembly that includes two different adhesives that are applied to opposing sides of a polymer substrate. While such an adhesive assembly can facilitate application of a glass overlay to the surface of a mobile device, the polymer substrate of the adhesive assembly generally has a different refractive index than the material (e.g., glass) forming the cover layer of the mobile device. The resulting index mismatch can further increase reflectance (particularly in the visible range) relative to the reflectance of the mobile device alone, making it even more difficult for a device user to view content on the device in high ambient lighting conditions.

[0007] Many mobile devices also include a visible light receiving components, such as one or more visible light cameras. Such cameras often include a relatively small aperture and relatively small optical components (e.g., lenses), and thus are often designed to maximize the amount of light entering the camera to maintain and/or improve the camera’ s performance in a variety of lighting conditions. With that in mind, it may be undesirable to use coatings, overlays, etc. that increase reflectance on the surface of a visible light receiving component such as a visible light camera, as the elevated reflectance will reduce the amount of light entering the camera. This is evidenced by the fact that many current glass overlays include a notch or opening for a visible light camera of a mobile device, such that the surface of the camera is not covered by the glass overlay. While such notches and openings allow the camera to remain unaffected by the overlay, they leave the surface of the camera unprotected.

[0008] Finally, mobile devices now frequently include infrared light emitting and receiving components such as an infrared camera and an infrared emitter. Such components may be used for various purposes. For example, such components may be used to facilitate unlocking of a mobile device, e.g., by enabling the creation of a mathematical model based on the illumination of a body part of the user with infrared light. While it may be desirable to protect such components, overlays (e.g., glass overlays) are often designed with visible light performance in mind and may undesirably affect the transmission and/or reception of infrared light by infrared light emitting and receiving components.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1A is a schematic top-down view of one example of a prior art mobile device.

[0010] FIG. IB is a schematic top down view of one example of an overlay assembly consistent with the present disclosure.

[0011] FIG. 1C is schematic side view of a mobile device and one example of an overlay assembly consistent with the present disclosure.

[0012] FIG. 2A is a schematic view of one example of the layer structure of an example overlay assembly consistent with the present disclosure. [0013] FIG. 2B is another schematic view of the layer structure of the overlay assembly of FIG. 2A.

[0014] FIG. 3 is a schematic view of an example of the layer structure of an example overlay assembly including an adhesive assembly consistent with the present disclosure.

[0015] FIG. 4A is a schematic view of one example of an overlay assembly consistent with the present disclosure on a mobile device component.

[0016] FIG. 4B is another schematic view of the overlay assembly of FIG. 4A on a mobile device component.

[0017] FIG. 5 is a plot of simulated reflectance (in percent) versus wavelength (in nanometers) for one example of an overlay assembly including a glass substrate and an antireflective (AR) stack, consistent with the present disclosure.

[0018] FIG. 6 is a plot of simulated reflectance (in percent) versus wavelength (in nanometers) for one example of an overlay assembly including a glass substrate, an antireflective (AR) stack, and an anti-fingerprint (AF) coating consistent with the present disclosure.

[0019] FIG. 7 is a plot of contact angle versus number of scratches measured from one example of an overlay assembly consistent with the present disclosure.

[0020] FIG. 8A is a schematic top-down view of another example of a prior art mobile device.

[0021] FIG. 8B is a schematic top down view of another example of an overlay assembly consistent with the present disclosure.

[0022] FIG. 9 is a comparison plot of measured reflectance versus wavelength between an actual measurement of the reflectance of the display of a 2018 IPHONE ® XS, the display of a 2018 IPHONE ® XS covered by an uncoated glass screen protector; the display of a 2018 APPLE® IPAD® 12.9”, the display of a 2018 APPLE ® MACBOOK® PRO 13”, and the display of a 2018 IPHONE® XS covered by an overlay assembly consistent with the present disclosure.

[0023] FIG. 10 is a comparison plot of measured reflectance versus wavelength between an actual measurement of the reflectance the front camera of a 2018 IPHONE ® XS, the front camera of a 2018 IPHONE ® XS covered by an uncoated glass screen protector; and the front camera of a 2018 IPHONE® XS covered by an overlay assembly consistent with the present disclosure.

[0024] FIG. 11 A is a comparison plot of measured reflectance versus wavelength between an actual measurement of the reflectance of the infrared camera of a 2018 IPHONE ® XS, the reflectance of the infrared emitter of a 2018 IPHONE ® XS, and the reflectance of the dot projector of a 2018 IPHONE® XS.

[0025] FIG. 1 IB is a magnified view of a region of FIG. 11 A.

[0026] FIG. 11C is a comparison plot of measured reflectance versus wavelength between an actual measurement of the reflectance of the infrared camera of a 2018 IPHONE ® XS, and the reflectance of the infrared camera of a 2018 IPHONE® XS covered by an overlay assembly consistent with the present disclosure.

[0027] FIG. 1 ID is a magnified view of a region of FIG. 11C.

[0028] FIG. 1 IE is a comparison plot of measured reflectance versus wavelength between an actual measurement of the reflectance of the dot projector of a 2018 IPHONE ® XS, and the reflectance of the dot projector of a 2018 IPHONE® XS covered by an overlay assembly consistent with the present disclosure.

[0029] FIG. 1 IF is a magnified view of a region of FIG. 1 IE.

DETAILED DESCRIPTION

[0030] Antireflective (AR) overlays for mobile devices and methods of forming the same are disclosed herein. The present disclosure particularly relates to AR glass overlays for mobile devices and components thereof, such as displays, visible light emitting/receiving components, and infrared light emitting/receiving components. The AR overlays of the present disclosure may exhibit a desirable combination of low visible light reflectance and high durability, making them well suited for mobile device and other applications. The AR overlays described herein may also be suitable for use over infrared light emitting/receiving components of a mobile device, such as an infrared camera, infrared emitter, and/or infrared dot projector. As a result, the AR overlays of the present disclosure may be used to protect the display, visible light components, and infrared light components of a mobile device, while imposing little or no negative impact on their respective performance. In the context of visible light receiving components (e.g., a visible light camera), the overlays described herein may increase the amount of visible light entering such components and reduce internal reflectance, which can improve or maintain the optical performance of such components in a variety of lighting environments.

[0031] In embodiments the AR overlays described herein include a base structure that includes a substrate having first and second opposing sides, and an AR stack on (e.g., directly on) the first side of the substrate. The substrate may be formed from or include glass or another suitable material. The AR stack includes a plurality of layers of differing refractive index. An optional anti-fingerprint (AF) coating may be disposed on (e.g., directly on) the uppermost layer of the AR stack. The base structure optionally further includes an optional adhesive assembly on (e.g., directly on) the second side of the substrate to facilitate application of the overlay to the cover layer of a mobile device display and/or visible/infrared light emitting/receiving

components thereof. In embodiments, the AR overlay exhibits an average reflectance of less than or equal to about 3% in a wavelength range of about 425 nanometers to about 675 nm. In further embodiments the AR overlay exhibits an average reflectance of less than or equal to about 2% in a wavelength range of about 425 nanometers to about 675 nm.

[0032] Mobile devices including a display, visible light camera, infrared light camera, and/or infrared light emitter and an AR overlay consistent with the present disclosure are also described herein. In embodiments the mobile device includes a display, and the AR overlay is configured such that when it is adhered to the display (e.g., a cover layer thereof), the average reflectance of the resulting system over said display is less than or equal to about 3.0 % (e.g., less than or equal to about 2.0 %) in a wavelength range of about 425 nanometers (nm) to about 675 nm. In those or other embodiments the mobile device includes a visible light camera, and the AR overlay is configured such that when it is adhered to the visible light camera (e.g., a cover layer thereof), the average reflectance of the resulting system over said visible light camera is less than or equal to about 3.0% in a wavelength range of about 425 nm to about 675 nm.

[0033] In those or still other embodiments the mobile device includes an infrared light camera and the AR overlay is configured such that when it is adhered to a surface of said infrared light camera (e.g., a cover layer thereof), an average reflectance of the resulting system over the infrared light camera is less than less than or equal to about 20.0% in a wavelength range of about 925 nanometers (nm) to about 975 nm. And in those or still other embodiments the mobile device includes an infrared emitter, and the AR overlay is configured such that when it is adhered to a surface of the infrared emitter (e.g., a cover layer thereof) an average reflectance of the resulting system over said infrared emitter is greater than or equal to about 80.0% in a wavelength range of about 690 nanometers (nm) to about 810 nm, and an average reflectance of the resulting system over said infrared light camera is less than or equal to about 15% in a wavelength range of about 815 nm to about 1100 nm.

[0034] FIG. 1A is a schematic top-down view of one example of a prior art mobile device. As shown, mobile device 100 includes a body 101, a display 103, a speaker 105, a visible light camera 107 and a button 109. As shown in FIG. 1C, mobile device 113 includes an upper surface 111, a lower surface 113, and beveled regions 115 between the upper and lower surfaces 111, 113. At least a portion of the upper surface 111 is formed by a cover layer (not separately shown) that is part of or disposed over display 103 and/or visible light camera 107. A wide variety of materials may be used as the cover layer of/over display 103 and/or visible light camera 107. Non-limiting examples of such materials include glass, polycarbonate, and sapphire. In embodiments, the cover layer of/over display 103 and/or visible light camera 107 is formed from glass.

[0035] FIG. IB depicts a top-down view of one example of an overlay assembly consistent with the present disclosure. As shown, overlay assembly 130 has a geometry that generally corresponds to the geometry of upper surface 111 of mobile device 100. In embodiments, overlay 130 includes one or more openings or notches, such as optional opening 131 and optional notch 133. Although not required, such notches and/or openings may be used in instances where overlay assembly 130 may interfere with or otherwise hinder the operation of an underlying component when it is mounted to the upper surface 111 of mobile device 100. For example, opening 131 and notch 133 may be configured to leave speaker 105 and button 109 uncovered by overlay assembly 130, wherein overlay assembly is mounted to upper surface 111.

[0036] Mobile device 100 is but one example of a possible mobile device configuration, and the configuration of overlay assembly 130 is but one example of a possible overlay configuration that is designed to mount thereto. For example, the configuration of mobile device 100 generally corresponds to the configuration of the display side of a 2018 IPHONE® XS sold by the APPLE® Corporation. While the shape of overlay assembly 130 is configured for use with the mobile device of FIG. 1A, myriad other overlay configurations are possible and are encompassed by the present disclosure. The same applies regarding the mobile device configuration shown in FIG. 10A and the configuration of the overlay assembly shown in FIG. 10B.

[0037] Put differently, the overlay assemblies described herein are not limited to the configurations shown in FIGS. IB and 10B. Rather such FIGS should be understood to illustrate example embodiments for the purposes of facilitating an understand of the overlays described herein and their potential end use. Indeed, the overlay assemblies described herein may be configured for use in a wide variety of mobile devices, such as but not limited to mobile phones, smart phones (e.g., APPLE® IPHONEs®, smart phones running the ANDROID® operating system (e.g. SAMSUNG® GALAXY® phones), tablet computers, laptop computers, automotive displays, mobile reading devices, mobile music players, mobile digital assistants, combinations thereof, and the like. [0038] FIG. 2A is a cross sectional diagram schematically illustrating a layer structure of one example of an overlay assembly 130 consistent with the present disclosure. As shown, overlay assembly 130 includes a base structure (not separately labeled) that includes a substrate 201 with opposing first and second sides, and an antireflective (AR) stack 203 on (e.g., directly on) the first side of the substrate. As further shown, the overlay assembly 130 may further include an optional adhesive assembly 205 on (e.g., directly on) the second side of the substrate 201. An optional anti-fingerprint (AF) coating 207 may also be formed on (e.g., directly on) the upper most layer of AF stack 203.

[0039] Substrate 201 may be formed from or include any material that is suitable for use in overlay/screen protector applications, such as glass, polycarbonate, sapphire, or the like.

Without limitation, in embodiments substrate 201 is formed from glass. Non-limiting examples of glasses that may be used to form substrate 201 include soda-lime glass, lead glass, flint glass, sodium borosilicate glass, oxide glass, or any other suitable glass material that is substantially transparent to visible and/or infrared light. As used herein the phrase,“substantially transparent to visible light” when used in conjunction with a material, layer, or component means that the material, layer, or component transmits at least 80% of light in a wavelength range of 400-700 nm. Similarly, the phrase,“substantially transparent to infrared light” when used in conjunction with a material, layer, or component means that the material, layer, or component transmits at least 80% of light in a wavelength range of 800 to 1100 nm. In embodiments, substrate 201 is made of GORILLA® Glass by CORNING ® Inc.

[0040] The refractive index of the substrate 201 may vary widely, and substrate 201 may have any suitable refractive index for overlay applications. In embodiments, substrate 201 is a glass substrate and exhibits a refractive index in the range of about 1.35 to about 1.7, such as about 1. 4 to about 1.6, or even about 1.45 to about 1.55. In specific non-limiting embodiments, substrate 201 is a glass substrate with a refractive index of about 1.45 to about 1.55, such as about 1.52.

[0041] The thickness of the substrate 201 may vary widely. For example, the thickness of substrate 201 may range from 100 microns (pm) to greater than 0.5 centimeters (cm). In some embodiments substrate 201 is a glass substrate having a thickness in the range of about 0.1 to about 2 millimeters (mm), such as about 0.2 to about 0.5 mm.

[0042] AR stack 203 is in the form of a plurality of alternating layers of differing refractive index. For example, and as shown in FIG. 2B, AR stack 203 may include alternating layers of high (209a) and low (21 lb) refractive index, where a and b are integers that are greater than or equal to 1. For convenience, the layers of high refractive index 209a may be referred to herein as high index layers, and the layers of low refractive index 211b may be referred to as low index layers.

[0043] The composition of the high and low refractive index layers 209a, 211b may vary widely, and any suitable material may be used to form such layers. Without limitation, in some embodiments the high and low refractive index layers 209a, 211b are each formed from a metal (e.g., Ti, Si, Zr, Mg, Ta etc.), a metal oxide (e.g., SiO, Si02, T1O2, ZrO, MgO, TaO, TaiOs etc.), a metal nitride (e.g., SiN, TiN, ZrN, TaN, etc.)), combinations thereof and the like. In embodiments the high refractive index layers 209a are each formed from a metal nitride, and the low refractive index layers 211b are each formed from a metal oxide. In those or other embodiments, the high refractive index layers 209a are each formed from silicon nitride (S13N4) (refractive index of about 1.9 to about 2.1), and the low refractive index layers 211b are each formed from silicon oxide (S1O2) (refractive index of about 1.44 to about 1.48).

[0044] While the present disclosure focuses on embodiments in which AR stack 203 includes two different types of layers (i.e., high refractive index layers 209a and low refractive index layers 21 lb), the instant application is not limited to such configurations. Indeed, the present disclosure envisions embodiments in which AR stack 203 includes more than two (e.g., 3, 4, 5 etc.) different types of layers therein, wherein each type of such layers differs in composition from each other type of layer in the AR stack 203.

[0045] The high refractive index layers 209a may have any suitable refractive index. In embodiments, the high refractive index layers 209a have a refractive index ranging from about 1.7 to about 2.3, such as from about 1.7 to about 2.2, from about 1.8 to about 2.1, or even from about 1.8 to about 2.0. Likewise, the low refractive index layers 211b may have any suitable refractive index. In embodiments, the low refractive index layers 211b have a refractive index ranging from about 1 to about 1.6, about 1.2 to about 1.6, about 1. 3 to about 1.6, about 1.4 to about 1.6, or even about 1.4 to about 1.5. In embodiments, the high refractive index layers 209a each have a refractive index of about 1.9 to about 2.0, and the low refractive index layers 21 lb each have a refractive index of about 1.44 to about 1.48.

[0046] The layers of AR stack 203 may be formed in any suitable manner. For example, the layers 209a, 211b may be formed using a plasma enhanced chemical vapor deposition (PE- CVD) process. Of course, the layers 209a, 21 lb may be made by other processes, such as but not limited to physical vapor deposition (e.g., thermal evaporation, sputtering, magnetron sputtering, etc.), atomic layer deposition, wet deposition methods, combinations thereof, and the like.

[0047] The thickness of the individual layers making up the AR stack 203 may vary widely. In general, the thickness of the layers within AR stack 203 is tuned to work in conjunction with other elements of the overlay assembly 130, e.g., substrate 201, adhesive assembly 205, optional anti-fingerprint coating 207, etc. In some embodiments the thickness of the layers within AR stack 203 are also tuned to work in conjunction with an optical treatment (coating(s), layer(s), etc.) on the cover layer or other components of a mobile device (e.g. visible and/or infrared light emitting/receiving components). In general, however, the thickness of each layer within the AR stack 203 may have a thickness ranging from greater than 0 to about 250 nm or more, such as from greater than 0 to about 150 nm, from greater than 0 to about lOOnm, or even greater than 0 to about 90 nm.

[0048] The number of layers in AR stack 203 is not limited, and AR stack 203 may include any suitable number of layers. With that in mind, the present disclosure focuses on embodiments in which AR stack 203 includes six layers, of which three layers are high index layers and three layers are low index layers. Such embodiments are for the sake of example only, and the AR stacks described herein are not limited thereto. Indeed, the present disclosure envisions and encompasses AR stacks that include any suitable total number of layers. For example, the total number of layers in AR stack 203 may be greater than or equal to 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 100, or more.

[0049] FIG. 3 depicts a schematic view of the layer structure of one example of an AR overlay 130 that includes an AR stack 203 with a total of six layers, including three high index layers 209a (i.e., 209i, 209₃, 209s) and three low index layers 21 lb (i.e., 211₂, 211₄, 211_ό). In specific non-limiting embodiments the AR stack 203 is formed directly on the first side of a glass substrate 201, and includes a high-index first layer 209₁ directly on the substrate 201, the high- index first layer 209₁ having refractive index of between about 1.9 and about 2.0 and a thickness of greater than 0 to about 20 nm; a low-index second layer 211₂ on the high index first layer, the low-index second layer 211₂ having refractive index of between about 1.44 and about 1.48 and thickness of between about 40 and about 60 nm; a high-index third layer 209₃ on the low-index second layer, the high index third layer 209₃ having refractive index of between about 1.9 and about 2.0 and a thickness of between about 40 and about 60 nm; a low-index fourth layer 211₄ on the high-index third layer, the low-index fourth layer 211₄ having refractive index of between about 1.44 and about 1.48 and thickness of greater than 0 to about 20 nm; a high-index fifth layer 209₅ on the low-index fourth layer 211₄, the high-index fifth layer 209s having refractive index of between about 1.9 and about 2.0 and thickness of between about 70 and about 100 nm; and a low-index sixth layer 21 \e on the high-index fifth layer 209s, the low-index sixth layer 21 1₆ having refractive index of between about 1.44 and about 1.48 and a thickness of between about 70 and about lOOnm.

[0050] The number, thickness, and material of the layers in AR stack 203 may be individually tailored to achieve a desired optical effect, and in some cases to work in conjunction with optical coatings or other features underlying the AR stack, such as but not limited to an adhesive assembly, optical coatings on the cover layer of a mobile device, and/or optical coatings used in visible or infrared light component of the mobile device (e.g., on a lens thereof). In any case, the number, makeup, and thicknesses of the layers in AR stack 203 may be selected such that AR overlay 130 provides a wide band antireflective effect in a wavelength range of about 400 to about 800 nm. For example, in embodiments AT overlay 130 (and, more particularly,

AR stack 203) is configured to exhibit an average reflectance of less than or equal to about 3% in wavelength range of about 425 to about 675 nm. In still further embodiments AT overlay 130 (and, more particularly, AR stack 203) is configured to exhibit an average reflectance of less than or equal to about 2% in wavelength range of about 425 to about 675 nm. And in still further embodiments, AT overlay 130 (and, more particularly, AR stack 203) is configured to exhibit an average reflectance of less than or equal to about 1.5% in wavelength range of about 425 to about 675 nm.

[0051] To demonstrate the above concepts, sample AR overlays 130 consistent with the structure of FIG. 3 were produced. The AR stack 203 of the samples included three S13N4 (209a) and three S1O2 (121b) layers, which were disposed in alternating fashion on the upper surface of the glass substrate 201, beginning with one of the high index S13N4 layers. The thickness of the respective layers in the AR stack 203 used in those samples is provided in Table 1 below. All refractive index values discussed within the context of this application refer to refractive index at 550nm. The AR stack 203 of the samples had an overall thickness of 283.2 nm. Of that overall thickness, the low index S1O2 layer thickness is 148.2nm or 52.3% of the total. Simulations of the optical reflectance of the designs were run, and the results are presented in FIG. 5. As shown, the optical simulations demonstrate that the samples were expected to exhibit an average reflectance of less than 3% (e.g., less than 2%, or even less than 1%) of visible light over the wavelength range of about 425 to about 725 nm.

Table 1: Layer thicknesses of one example AR stack

[0052] As noted above an adhesive assembly 205 may be disposed on (e.g., directly on) a second side of the substrate 201. In general, the adhesive assembly 205 functions to facilitate the adherence of the AR overlay 130 to the cover layer or other component of a mobile device. The type, nature and structure of adhesive assembly 205 is not limited, and any suitable adhesive assembly may be used. For example, in embodiments adhesive assembly 205 may be in the form of a single layer of an adhesive composition (e.g., as shown in FIG. 2A), such as an acrylic adhesive, a silicone adhesive, an epoxy, or the like. In embodiments the adhesive assembly 205 is in the form of a multilayer structure. For example, and as shown in FIG. 2B, adhesive assembly 205 may include an adhesive substrate 213 having opposed first (lower) and second (upper) sides, wherein a first adhesive 215 is formed on (e.g., directly on) the first (lower) side of the adhesive substrate 213, and a second adhesive 217 is formed on (e.g., directly on) the second (upper) side of the adhesive substrate 213. The first adhesive 215 is configured to facilitate coupling of the adhesive substrate 213 to a cover layer or other component of a mobile device.

In contrast the second adhesive 217 is configured to facilitate coupled of the adhesive substrate 213 to substrate 201.

[0053] Adhesive substrate 213 may be made of any suitable material for optical

applications, provided that is substantially transparent to visible and/or infrared light. For example, adhesive substrate 213 may in the form of a film or layer of material that is substantially transparent to visible and infrared light. Non-limiting examples of materials that may be used as adhesive substrate 213 include films and layers including or formed from one or more acrylate polymers, methacrylate polymers, terephthalate polymers, combinations thereof, and the like. In embodiments, adhesive substrate 213 is a film or layer of polyethylene terephthalate (PET) having a thickness on the range of greater than 0 to about 500 microns, such as from greater than 0 to about 100 microns.

[0054] First adhesive 215 may be made of or include any suitable adhesive material. In embodiments, the first adhesive is made of or includes an adhesive that can strongly adhere adhesive substrate 213 (e.g., PET) to the (glass) cover layer or another component of a mobile device. Non-limiting examples of suitable adhesives that may be used as first adhesive 215 include silicone adhesives, acrylic adhesives, epoxy adhesives, combinations thereof, and the like. In some embodiments, first adhesive 215 is in the form of a layer of silicone adhesive having a thickness of greater than 0 to about 500 microns, such as from greater than 0 to about 250 microns, or even from greater than 0 to about 100 microns.

[0055] Second adhesive 217 may be made of or include any suitable adhesive material. In embodiments, the second adhesive is made of or includes an adhesive that can strongly adhere adhesive substrate 213 (e.g., PET) to the (glass) substrate 201. Non-limiting examples of suitable adhesives that may be used as second adhesive 217 include silicone adhesives, acrylic adhesives, epoxy adhesives, combinations thereof, and the like. In some embodiments, second adhesive 217 is in the form of a layer of acrylic adhesive having a thickness of greater than 0 to about 500 microns, such as from greater than 0 to about 250 microns, or even from greater than 0 to about 100 microns.

[0056] In specific non-limiting embodiments, the adhesive assembly 205 when used includes a PET substrate 213 having a thickness of about 40 to about 60 microns, a first adhesive 215 in the form of a layer of silicone adhesive having a thickness of 40 to about 60 microns on the first (lower) side of the PET substrate 213, and a second adhesive 217 in the form of a layer of acrylic adhesive having a thickness of about 40 to about 60 microns on the second side of PET substrate 213. One example of such an adhesive assembly is the A/B glue sold under part number CPF50(50)-SL(50)-AL50(50) by NIPPA® corporation.

[0057] As also noted above an anti-fingerprint coating 207 may optionally be formed on an upper surface of AR stack 203. A wide variety of anti-fingerprint coatings are known and any suitable anti-fingerprint coating may be used. In some embodiments, the anti-fingerprint coating 207 is an anti-fingerprint, anti-smudge fluoropolymer layer, such as those known in the art. Without limitation, in some embodiments, the anti-fingerprint coating 207 includes an interface layer, a primer layer, and an anti-fingerprint layer, all of which are not shown in the FIGS. Such layers may be applied in any suitable manner, such as by a wet coating process or a vacuum evaporation process. Without limitation, in some embodiments anti-fingerprint coating 207 is a fluoropolymer layer that is applied via a dip coating process.

[0058] When used, it may be desired to tailor the layers of AR stack 203 to work in conjunction with AF layer 207, to achieve an overlay assembly that exhibits desired optical performance. To illustrate that concept, sample overlay assemblies including an AR stack 203 and an AF coating 207 were formed. The AR stack of those samples was formed of the same materials and general layer structure as the AF stack discussed above regarding Table 1 and FIG. 5. The anti-fingerprint coating 207 used in these samples had an index of refraction of 1.35 was formed on the surface of the uppermost layer of the AR stack 203. The thickness of the individual layers in the AR stack 203 and the anti-fingerprint coating 207 for these samples are reported in table 2 below.

Table 2: Layer thicknesses for an example AR stack with an Anti-fingerprint Coating

[0059] As can be seen, the thickness of the uppermost layer 21 U, in the AR stack 203 of these samples was adjusted (relative to the thickness of the uppermost layer 21 \e in Table 1) to account for the impact of the anti-fingerprint layer 207. The optical performance of the resulting structure was simulated and the results are plotted in FIG. 6. As can be seen, the sample exhibited an average reflectance of less than 3.0 % (e.g., less than 2.0 % or even less than 1.0%) in a wavelength range of about 425 nm to about 675nm.

[0060] The samples were also subject to scratch testing to determine their scratch resistance. Such testing was performed using an automated scratch tester with #0000 and #00 steel wool covering a 1 cm²“finger" and using a 1000-gram weight. Scratch resistance was evaluated by counting the number of scratches observed relative to the contact angle. As shown in FIG. 7 the samples exhibited good scratch resistance, with the contact angle remaining above 90 degrees after 4000 scratches.

[0061] As discussed above, overlay assemblies consistent with the present disclosure may be used to protect various components of a mobile device, while also providing desirable optical performance. For example, overlay assemblies consistent with the present disclosure may be used to protect mobile device components such as a display, a visible light emitting and receiving components (e.g., a visible light camera), infrared light emitting and receiving components (e.g., an infrared emitter and/or infrared camera), combinations thereof, and the like. More specifically, the overlay assemblies described herein may be configured such that they can be adhered or otherwise coupled to/over one or more components of a mobile device. By adhering and/or coupling the overlay assembly to the mobile device component, the

advantageous physical properties (e.g. of the substrate 201) may substantially protect the underlying device component. At the same time, the overlay assembly (or, more particularly, the AR stack 203 thereof) may be configured to maintain or enhance the optical performance of the underlying mobile device component.

[0062] For example, when an overlay assembly described herein is adhered or otherwise mounted to/over a visible light camera of a mobile device, the resulting system may exhibit a lower reflectance in the visible range, relative to the reflectance in the visible range of the mobile device component (and/or overlying cover layer of the mobile device) without the overlay assembly. Consequently, use of the overlay assemblies described herein may be used to increase the amount of visible light entering a visible light camera of a mobile device, while also protecting such components from physical damage. [0063] Similarly, when an overlay assembly described herein is adhered or otherwise mounted to/over an infrared light component of a mobile device, the resulting system may exhibit the same or about the same reflectance in the infrared range, relative to the reflectance of the mobile device component (and/or overlying cover layer of the mobile device) in the infrared range without the overlay assembly. Consequently, the overlay assemblies described herein may be used to protect an infrared camera from physical damage, without or without substantially affecting the amount of infrared light entering the infrared light camera relative to the amount of infrared light received by the infrared camera without the use of the overlay assembly. Likewise, the overlay assemblies described herein may be used to protect an infrared emitter from physical damage, without or without substantially affecting the amount of infrared light that may be transmitted from the infrared emitter into the surrounding environment, relative to the amount of infrared light transmitted by the infrared emitter without the use of the overlay assembly.

[0064] FIG. 4A is a schematic view of one example of a layer structure of an example overlay assembly consistent with the present disclosure on a mobile device component. In this embodiment, the overlay assembly 130 (which is of the same structure as overlay assembly 130 described above) is adhered or otherwise coupled directly to a mobile device component 401. Mobile device component 401 may be any component of a mobile device, such as but not limited to a display, a visible light transmitting or receiving component (e.g., visible light camera or visible light emitter), an infrared light transmitting or receiving component (e.g., an infrared light camera or an infrared light emitter such as an infrared flood assembly or infrared dot projector)), a speaker, a button, combinations thereof, and the like. Without limitation, in embodiments mobile device component is a mobile device display, a visible light camera, an infrared light camera, an infrared light emitter, or a combination of two or more thereof.

[0065] In the embodiment of FIG. 4A, overlay assembly 130 is shown as being adhered or otherwise coupled directly to an upper surface of the mobile device component 401. Such illustration is for the sake of example, and that one or more additional features may be present between the mobile device component 401 and overlay assembly 130. For example, overlay assembly 130 may be adhered or otherwise coupled to a cover layer or other element that is disposed over mobile device component 401. In embodiments, a (e.g., glass) cover layer of a mobile device is disposed on/over mobile device component 401, and overlay assembly 130 is adhered to or otherwise coupled to the cover layer, such that at least a portion of the overlay assembly 130 is disposed over the mobile device component 401.

[0066] For the sake of simplicity and ease of understanding mobile device component 401 is shown in FIG. 4A in the form of a single layer. FIG. 4A depicts a simplified representation of a surface of mobile device component 401, and the mobile device component 401 may include complex (e.g., non-planar) surfaces. In addition, mobile device component may include optical treatments such as coatings, layer structures, etc. That concept is illustrated in FIG. 4B, which depicts one example in which mobile device component 401 includes a component element 403, a component optical treatment 405, and a component surface 407. The component element 403 may be any type of element, and may depend on the nature of mobile device component 401.

For example, when mobile device component 401 is a light emitting or receiving device such as a camera or a lamp/emitting surface, component element 403 may be a lens or other light transmitting component. In such instances, optical treatment 405 may include coatings, layers, etc. that may be designed to impact optical characteristics of the mobile device component 401, such as the amount and type of light emitted and received thereby. Non-limiting examples of optical treatment 405 include optical coatings and layers configured to produce a desired optical effect, such as bandpass filtering/transmission, notch filtering/transmission, and the like.

Component surface 407 may be a surface of the mobile device component 401 itself, or a cover layer of a mobile device that overlies mobile device component 401. In embodiments, component surface 407 is a glass cover layer of a mobile device that overlies mobile device component 401.

[0067] In such instances it may be desirable to configure overlay assembly 130 (and more particularly, AR stack 203) to work in conjunction with optical treatment 405, component surface 407, to attain desired final optical performance. For example, when optical treatment 405 is designed to provide bandpass or notch filtering/transmission characteristics, AR stack 203 may be designed to maintain or substantially maintain those characteristics while simultaneously providing a broadband antireflective effect in the visible light region of the electromagnetic spectrum.

[0068] For example, in embodiments mobile device component 401 is or includes a mobile device display, and the antireflective overlay 130 is configured such that when it is adhered or otherwise coupled to a surface of the display (e.g., a mobile device cover layer over the display), an average reflectance of the resulting system over said display (i.e., of the display, optional mobile device cover layer, and the overlay assembly) is less than or equal to about 3% (e.g., less than about 2% or even less than about 1.5%) in a wavelength range of about 425 nanometers

(nm) to about 675 nm. [0069] In other embodiments mobile device component 401 is or includes a visible light camera, and the AR overlay 130 is configured such that when it is adhered or otherwise coupled to a surface of said visible light camera (e.g., a mobile device cover layer over the visible light camera), an average reflectance of the resulting system over said visible light camera (i.e., of the visible light camera, optional mobile device cover layer, and the overlay assembly) is less than or equal to about 3.0% (e.g., less than about 2.0 % or even less than about 1.5%) in a wavelength range of about 425 nanometers (nm) to about 675 nm.

[0070] In further embodiments the mobile device component 401 is or includes an infrared light camera, and the AR overlay 130 is configured such that when it is adhered or otherwise coupled to a surface of said infrared light camera (e.g., a mobile device cover layer over the infrared light camera), an average reflectance of the resulting system over said infrared light camera (i.e., of the infrared light camera, optional mobile device cover layer, and the overlay assembly) is less than or equal to about 20.0% (e.g., less than or equal to about 18%, or even less than or equal to about 15%) in a wavelength range of about 925 nanometers (nm) to about 975 nm.

[0071] In further embodiments the mobile device component 401 is or includes an infrared light emitter, and the AR overlay 130 is configured such that when it is adhered or otherwise coupled to a surface of said infrared light emitter (e.g., a mobile device cover layer over the infrared light emitter), an average reflectance of the resulting system over said infrared light emitter (i.e., of the infrared light emitter, optional mobile device cover layer, and the overlay assembly) is greater than or equal to about 80.0% in a wavelength range of about 690

nanometers (nm) to about 810 nm, and an average reflectance of the resulting system over said infrared light camera is less than or equal to about 15% in a wavelength range of about 815 nm to about 1100 nm

[0072] Mobile devices including a display, visible light camera, infrared light camera, and/or infrared light emitter and an AR overlay consistent with the present disclosure are also described herein. In embodiments the mobile device includes a display, and the AR overlay is configured such that when it is adhered to the display (e.g., a cover layer thereof), the average reflectance of the resulting system over said display is less than or equal to about 3.0 % (e.g., less than or equal to about 2.0 %) in a wavelength range of about 425 nanometers (nm) to about 675 nm. In those or other embodiments the mobile device includes a visible light camera, and the AR overlay is configured such that when it is adhered to the visible light camera (e.g., a cover layer thereof), the average reflectance of the resulting system over said visible light camera is less than or equal to about 3.0% in a wavelength range of about 425 Nm to about 675 nm.

[0073] In those or still other embodiments the mobile device includes an infrared light camera and the AR overlay is configured such that when it is adhered to a surface of said infrared light camera (e.g., a cover layer thereof), an average reflectance of the resulting system over the infrared light camera is less than less than or equal to about 20.0% in a wavelength range of about 925 nanometers (nm) to about 975 nm. And in those or still other embodiments the mobile device includes an infrared emitter, and the AR overlay is configured such that when it is adhered to a surface of the infrared emitter (e.g., a cover layer thereof) an average reflectance of the resulting system over said infrared emitter is greater than or equal to about 80.0% in a wavelength range of about 690 nanometers (nm) to about 810 nm, and an average reflectance of the resulting system over said infrared light camera is less than or equal to about 15% in a wavelength range of about 815 nm to about 1100 nm.

[0074] Of course, the AR overlays described herein are not limited to covering a single type of mobile device component. In embodiments the AR overlays described herein may be used to cover/protect multiple types of mobile device components, while providing desired optical performance. For example, in embodiments the AR overlays described herein are coupled to the surface of one or a combination of a mobile device display, a visible light camera, an infrared camera, and an infrared emitter, with the resulting system exhibiting the above noted optical properties above each respective mobile device component. As before, the surface of the mobile device display, visible light camera, infrared camera, and infrared emitter may be the surface of a mobile device cover layer overlying such components.

TEST SAMPLES

[0075] To investigate their usefulness, several sample AR overlays 830 consistent with the present disclosure were prepared and were applied to the cover layer of a mobile device of the configuration shown in FIG. 8 A, namely a 2018 APPLE® IPHONE® XS. As shown in FIG.

8A, the mobile device 800 includes device body 801, a display 803, a speaker 805, a visible light camera 807, an ambient light sensor 809, an infrared dot projector 811, an infrared camera 813, and infrared emitter 815 (e.g., an infrared flood illuminator), and a proximity sensor 817. The mobile device 800 further includes a glass cover layer (not shown) covering each of the foregoing components.

[0076] The sample AR overlays 830 were of the general configuration shown in FIG. 8B.

As shown, the AR overlays 830 were designed to adhere to and cover the entire top surface of the mobile device 800, including display 803, visible light camera 807, infrared camera 813 and infrared emitter 815. An optional speaker cutout 831 was also formed in some samples. Each of the sample AR overlays 830 included a glass substrate 201 and an AR stack 203 configured in the manner shown in FIG. 3, with the layer composition and thicknesses shown in FIG. 1. Each of the layers of AR stack 203 were deposited by Plasma-enhanced Chemical Vapor Deposition using appropriate process conditions and source gases.

[0077] More specifically, the AR overlays 830 included an AR stack that included a total of three Si3N4 layers and three S1O2 layers that were alternately deposited on the upper surface of a glass substrate. The first layer of the AR stack was a S13N4 layer having a refractive index of 1.97 and a thickness of 12 nm. Deposition was performed by plasma enhanced chemical vapor deposition (PE-CVD) using S1H4 as the precursor gas, which was delivered with NH3 and N2 to a plasma source as a carrier bearing the substrate was moved past the source. The ratio of S1H4 to NH3 and N2 was 5:4:4 (200 seem S1H4, 160 seem NH3, 160 seem N2), and the alternating current ion source was operated at 12A as the carrier was moved at 5.233 m/min.

[0001] A first layer of S1O2 having a refractive index of 1.46 and a thickness of 47.9 nm was then deposited on the first layer of S13N4. The first S1O2 layer was formed via PE-CVD using S1H4 as the precursor gas, which was delivered to the plasma source with oxygen gas as the carrier was moved past the source. The ratio of oxygen to S1H4 was 5:1 (600 seem Oxygen, 120 seem SiH4) and the AC ion source was operated at 14A while the carrier moved at a rate of 1.658 m/min.

[0002] The following layers of S13N4 and S1O2 were then alternately deposited in much the same manner as the first S13N4 and S1O2 layers, using the following processing parameters: second S13N4 layer (refractive index of 1.97, physical thickness 41.9 nm, 12A, Carrier Speed 1.52m/min); second SiC layer (refractive index of 1.46, physical thickness 12 nm, 14A, Carrier speed 6.011 m/min); third S13N4 (refractive index of 1.97, physical thickness 81.2 nm, 12A, Carrier Speed 0.776 m/min); third SiC layer (refractive index of 1.46, physical thickness 8735 nm, 14A, Carrier speed 0.9 m/min). The resulting AR overlays 830 had the general layer structure shown in FIG. 3. Following the formation of the AR stack, a fluoropolymer anti fingerprint coating was provided on some of the samples via vacuum evaporation.

[0003] An adhesive assembly 205 was provided on the device facing surface of the sample AR overlays 830. The adhesive assembly included a polyethylene terephthalate (PET) substrate 213 having a thickness of 50 microns, a 50-micron thick layer of silicone adhesive applied to the lower surface of the PET substrate, and a 50-micron thick layer of acrylic adhesive applied to the upper surface of the PET substrate. The adhesive assembly was adhered to the lower (device facing) surface of the substrate 201 using the acrylic adhesive side of the adhesive assembly 205. The resulting structure was then adhered to the cover layer of the mobile device 800 using the silicone adhesive side of the adhesive assembly 205.

[0004] The reflectance of the AR overlays 830 as applied to the cover layer of the mobile device 800 was measured at various points above components of the mobile device 800.

Specifically, reflectance measurements were taken of the AR overlays 830 above the display 803, the visible light camera 807, the infrared camera 813, and the infrared emitter 815 of the mobile device 800. The results were plotted against reflectance measurements that were taken of the display 803, the visible light camera 807, the infrared camera 813, and the infrared emitter 815 of mobile device 800 without AR overlay 830. The results are shown in FIGS. 9, 10, and 11C-11F.

[0005] FIG. 9 is a comparison plot of reflectance versus wavelength between the measured reflectance 901 of the display of a 2018 IPHONE ® XS, the reflectance 903 of the display of a 2018 IPHONE ® XS covered by an uncoated glass screen protector; the measured reflectance 907 display of a 2018 APPLE® IPAD® 12.9”, the reflectance 909 of the display of a 2018 APPLE ® MACBOOK® PRO 13”, and the measured reflectance 905 of the display of a 2018 IPHONE® XS covered by an overlay assembly consistent with the present disclosure in a range of 375 to 675 nm. As shown, the measured reflectance 901 of the display of a 2018 IPHONE ® XS ranged from about 6.0% at 400nm to about 5.0% at 725 nm, with an average reflectance of about 4.4% over the measured range. The measured reflectance 903 of the display of a 2018 IPHONE ® XS covered by an uncoated glass overlay ranged from about 7.0% at 400nm to about 6.0% at 725 nm, with an average reflectance of about 5.5% over the measured range. In contrast, the measured reflectance 905 of the display of a 2018 IPHONE ® XS covered by an overlay assembly 830 consistent with the present disclosure ranged from about 5.0% at 400nm to about 3.0% at 725 nm, with an average reflectance of about 1.37% over the measured range.

[0006] FIG. 10 is a comparison plot of measured reflectance versus wavelength between the measured reflectance 1001 of the visible light camera (front camera) of a 2018 IPHONE ® XS, the measured reflectance 1003 of the visible light camera of a 2018 IPHONE ® XS covered by an uncoated glass screen protector, and the measured reflectance 1007 of the visible light camera of a 2018 IPHONE® XS covered by an overlay assembly consistent with the present disclosure in a range of 375 to 675 nm. As shown, the measured reflectance 1001 of the visible light camera of the 2018 IPHONE ® XS ranged from about 10.0% at about 415nm to about 7.0% at about 670 nm, with an average reflectance of about 5.8% over the measured range. The measured reflectance 1003 of the visible light camera of the 2018 IPHONE ® XS covered by an uncoated glass overlay ranged from about 11.0% at about 415nm to about 7.0% at about 670 nm, with an average reflectance of about 6.9% over the measured range. In contrast, the reflectance 1005 of the visible light camera of the 2018 IPHONE ® XS covered by an overlay assembly 830 consistent with the present disclosure ranged from about 3.0% at about 415nm to about 2.0% at about 675 nm, with an average reflectance of about 2.2% over the measured range. Moreover, the reflectance 1005 was noticeably flatter over the measured range than the reflectance 1001 of the visible light camera or the reflectance 1003 of the visible light camera and the uncoated glass overlay.

[0007] FIGS. 11A and 1 IB depicts comparison plots of reflectance versus wavelength between the measured reflectance 1101 of the infrared camera of a 2018 IPHONE ® XS, the measured reflectance 1103 of the infrared emitter of a 2018 IPHONE ® XS, and the measured reflectance 1105 of the dot projector of a 2018 IPHONE® XS. As shown, the reflectance 1101 data measured from the infrared camera 813 suggests that the infrared camera bears an optical treatment that acts as a bandpass filter that substantially rejects (reflects) infrared light in the range of about 830 to 925 nm (reflectance of about 70%) and from about 970 to about 1000 nm (reflectance of about 70%), but substantially transmits infrared light in a range of about 925 to about 970nm (reflectance of less than about 20%). In contrast, the reflectance 1103, 1105 showed significant reflection in the range of about 700 to about 800 nm (reflectance of greater than 90%), but largely transmitted light in the range of about 810 to about 1000 nm (reflectance of less than 10%).

[0008] FIGS. 11C and 1 ID are comparison plots of reflectance versus wavelength between the measured reflectance 1101 of the infrared camera of the 2018 IPHONE ® XS, and the measured reflectance 1107 of the infrared camera of a 2018 IPHONE® XS covered by an overlay assembly 830 consistent with the present disclosure. As shown, the reflectance 1107 of the samples bearing the overlay assembly substantially tracked the reflectance 1101 of the infrared camera without the overlay assembly. Most notably, the bandpass characteristics of the infrared camera without the overlay assembly were generally maintained after the application of the overlay assembly. This is demonstrated by the reflectance 1107 within the range of about 925 to about 975nm, which was slightly higher than the reflectance 1101 within that range but still below 20%. While the reflectance 1107 showed a slight narrowing of the bandpass region (i.e., reducing the region from 925-975nm to about 925-about 965nm as shown in FIG. 1 ID), testing revealed the such narrowing did not affect the functional operation of the infrared camera.

[0009] FIGS. 1 IE and F are comparison plots of reflectance versus wavelength between an actual measurement of the measured reflectance 1103 of the infrared dot projector of a 2018 IPHONE ® XS, and the measured reflectance 1109 of the infrared dot projector of a 2018

IPHONE® XS covered by an overlay assembly consistent with the present disclosure. As shown, the reflectance 1109 of the samples bearing the overlay assembly substantially tracked the reflectance 1103 of the infrared dot projector without the overlay assembly. Most notably, the bandpass characteristics of the infrared dot projector without the overlay assembly (i.e., in the range of about 400 to about 700nm and about 800 to about 1 lOOnm) were generally maintained after the application of the overlay assembly. This is demonstrated by the reflectance 1109 within the range of about 400 to about 700nm (i.e., reflectance less than about 10%), and the reflectance 1109 within the range of about 825 to about 1100 nm (i.e., reflectance of less than about 15%) 925 to about 975nm, which was slightly higher than the reflectance 1101 within that range but still below 20%. The band filter characteristics of the reflectance 1103 were also generally maintained, as shown by the reflectance 1109 within the range of about 700 to about 800 nm. While the reflectance 1109 was greater than the reflectance 1103 in the range of about 930 to about 1000 nm (as best shown in FIG. 1 IF), testing revealed the such narrowing did not affect the functional operation of the infrared dot projector.

[0010] As used herein, the terms“about” and“substantially” when used regarding a numerical value or range means +/- 5% of the recited numerical value or range.

[0011] As used herein, the term“on” may be used to describe the relative position of one component (e.g., a first layer) relative to another component (e.g., a second layer). In such instances the term“on” should be understood to indicate that a first component is present above a second component, but is not necessarily in contact with one or more surfaces of the second component. That is, when a first component is“on” a second component, one or more intervening components may be present between the first and second components. In contrast, the term“directly on” should be interpreted to mean that a first component is in contact with a surface (e.g., an upper surface) or a second component. Therefore, when a first component is “directly on” a second component, it should be understood that the first component is in contact with the second component, and that no intervening components are present between the first and second components. [0012] Ranges are used herein to describe various features of elements of the present disclosure. The ranges enumerated herein are for the sake of example only, unless expressly indicated otherwise. The ranges herein should also be understood to include all the individual values of falling within the indicated range as though such values were expressly recited, and to encompass sub ranges within the indicated range as though such sub ranges were expressly recited. By way of example, a range of 1 to 10 should be understood to include the individual values of 2, 3, 4... etc., as well as the sub ranges of 2 to 10, 3 to 10, 2 to 8, etc., as though such values and sub ranges were expressly recited.

[0013] Other than in the examples, or where otherwise indicated, all numbers expressing endpoints of ranges, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed considering the number of significant digits and ordinary rounding approaches.

[0014] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

CLAIMS What is claimed is:

1. An antireflective (AR) overlay for mounting to a mobile device, comprising:

a base structure comprising:

a glass substrate comprising a first side and a second side opposing the first side; and

an AR stack on the first side of the glass substrate, the AR stack comprising a plurality of layers of differing refractive index;

wherein the antireflective overlay exhibits a reflectance of less than or equal to about 3% in wavelength range of 425 nanometers (nm) to 675 nm.

2. The AR overlay of claim 1, wherein the AR stack comprises a plurality of alternating layers of low refractive index and a plurality of layers of high refractive index, the plurality of low refractive index having a relatively low refractive index, as compared to the plurality of high refractive index layers.

3. The AR overlay of claim 2, wherein the each of plurality of low refractive index layers consist of a first material having a refractive index ranging from about 1.44 to about 1.48.

4. The AR overlay of claim 2, wherein each of the plurality of high refractive index layers consist of a first material having a refractive index ranging from about 1.9 to about 2.0.

5. The AR overlay of claim 2, wherein each of the plurality of low refractive index layers consist of a silicon oxide, and each of the plurality of high refractive index materials consist of a silicon nitride.

6. The AR overlay of claim 3, wherein:

the AR stack is formed directly on the glass substrate, and said plurality of layers include, in succession:

a high-index first layer having refractive index of between about 1.9 and about 2.0 and a thickness of greater than 0 to about 20 nm;

a low-index second layer having refractive index of between about 1.44 and about

1.48 and thickness of between about 40 and about 60 nm;

a high-index third layer having refractive index of between about 1.9 and about 2.0 and a thickness of between about 40 and about 60 nm;

a low-index fourth layer having refractive index of between about 1.44 and about

1.48 and thickness of greater than 0 to about 20 nm; and

a high-index fifth layer having refractive index of between about 1.9 and about 2.0 and thickness of between about 70 and about 100 nm; and

a low-index sixth layer having refractive index of between about 1.44 and about

1.48 and a thickness of between about 70 and about lOOnm; and

wherein a total thickness of the adhesion layer and the low-index first layer is between about 100 nanometers (nm) and about 130 nm.

7. The AR overlay of claim 1, further comprising an adhesion assembly on the second side of the glass substrate.

8. The AR overlay of claim 7, wherein the adhesion assembly comprises:

an adhesion substrate having opposing first and second sides;

a first adhesive on the first side of the adhesion substrate; and

a second adhesive of the second side of the adhesion substrate;

wherein the second adhesive differs from the first adhesive.

9. The AR overlay of claim 8, wherein:

the adhesion substrate comprises a terephthalate polymer;

the first adhesive comprises an acrylic adhesive;

and the second adhesive comprises a silicone adhesive.

10. The AR overlay of claim 9, wherein the adhesion substrate is polyethylene terephthalate.

11. The AR overlay of claim 6, further comprising an adhesion assembly on the second side of the glass substrate, wherein the adhesion assembly comprises:

an adhesion substrate having opposing first and second sides;

a first adhesive on the first side of the adhesion substrate; and

a second adhesive of the second side of the adhesion substrate;

wherein the second adhesive differs from the first adhesive.

12. The AR overlay of claim 11, wherein:

the adhesion substrate comprises a terephthalate polymer;

the first adhesive comprises an acrylic adhesive;

and the second adhesive comprises a silicone adhesive.

13. The AR overlay of claim 12, wherein the adhesion substrate is polyethylene

terephthalate.

14. The AR overlay of claim 1, wherein:

said mobile device comprises a display; and

when said antireflective overlay is adhered to a surface of said display, an average reflectance of the resulting system over said display is less than less than or equal to about 3% in a wavelength range of about 425 nanometers (nm) to about 675 nm.

15. The AR overlay of claim 6, wherein:

said mobile device comprises a display; and

16. The AR overlay of claim 6, wherein: said mobile device comprises a display; and

17. The AR overlay of claim 1, wherein:

said mobile device comprises a visible light camera; and

when said antireflective overlay is adhered to a surface of said visible light camera, an average reflectance of the resulting system over said visible light camera is less than less than or equal to about 3.0% in a wavelength range of about 425 nanometers (nm) to about 675 nm.

18. The AR overlay of claim 6, wherein:

said mobile device comprises a visible light camera; and

19. The AR overlay of claim 9, wherein:

said mobile device comprises a visible light camera; and

20. The AR overlay of claim 1, wherein:

said mobile device comprises an infrared light camera; and

when said antireflective overlay is adhered to a surface of said infrared light camera, an average reflectance of the resulting system over said infrared light camera is less than less than or equal to about 20.0% in a wavelength range of about 925 nanometers (nm) to about 975 nm.

21. The AR overlay of claim 6, wherein:

said mobile device comprises an infrared light camera; and

22. The AR overlay of claim 9, wherein:

said mobile device comprises an infrared light camera; and

23. The AR overlay of claim 1, wherein:

said mobile device comprises an infrared emitter; and when said antireflective overlay is adhered to a surface of said infrared emitter, an average reflectance of the resulting system over said infrared emitter is greater than or equal to about 80.0% in a wavelength range of about 690 nanometers (nm) to about 810 nm, and an average reflectance of the resulting system over said infrared light emitter is less than or equal to about 15% in a wavelength range of about 815 nm to about 1100 nm.

24. The AR overlay of claim 6, wherein:

said mobile device comprises an infrared emitter; and

when said antireflective overlay is adhered to a surface of said infrared emitter, an average reflectance of the resulting system over said infrared emitter is greater than or equal to about 80.0% in a wavelength range of about 690 nanometers (nm) to about 810 nm, and an average reflectance of the resulting system over said infrared light emitter is less than or equal to about 15% in a wavelength range of about 815 nm to about 1100 nm.

25. The AR overlay of claim 9, wherein:

said mobile device comprises an infrared emitter; and