Textured region comprising low refractive index substrate having higher elevation surface and lower elevation surface and high refractive index material disposed on lower elevation surface for reducing specular reflectance

Abstract

A substrate for a display article, the substrate comprising: (a) a major surface; and (b) a textured region on at least a portion of the major surface, the textured region comprising: (i) one or more higher surfaces at a higher average elevation parallel to a base plane disposed below the textured region and extending through the substrate; (ii) one or more lower surfaces located at a lower average elevation, the lower average elevation parallel to the base plane, the lower average elevation being less than the higher average elevation; and (iii) a high index material disposed on each of the one or more lower surfaces at the lower average elevation, the high index material forming one or more intermediate surfaces at an intermediate average elevation, the intermediate average elevation being parallel to the base plane, the intermediate average elevation is greater than the lower average elevation but less than the higher average elevation, and the high refractive index material comprises a refractive index that is greater than the refractive index of the substrate.

Description

[0001] This invention patent application is a divisional application of the invention patent application with international application number PCT / US2021 / 040772, international application date July 8, 2021, Chinese national phase application number 202180048987.2, and invention title "Textured region of high refractive index material disposed on lower elevation surface for reducing specular reflectivity, comprising a low refractive index substrate having a higher elevation surface and a lower elevation surface".

[0002] Priority Claim

[0003] This application claims priority to U.S. Provisional Application No. 63 / 049,843, filed July 9, 2020, which is incorporated herein by reference in its entirety.

[0004] Cross-references to related applications

[0005] This application relates to, but does not claim priority to, the following jointly owned and assigned patent applications: U.S. Patent Application No. __________ (D31038 / 32632), filed in _____ and entitled “ANTI-GLARE SUBSTRATE FOR A DISPLAY ARTICLE INCLUDING ATEXTURED REGION WITH PRIMARY SURFACE FEATURES AND SECONDARY SURFACEFEATURESIMPARTING A SURFACE ROUGHNESS THAT INCREASES SURFACE SCATTERING”; and U.S. Patent Application No. __________ (D31038 / 32632), filed in _____ and entitled “TEXTUREDREGION OF A SUBSTRATE TO REDUCE SPECULAR REFLECTANCE INCORPORATING SURFACEFEATURES WITH AN ELLIPTICAL PERIMETER OR SEGMENTS THEREOF, AND METHOD OF MAKING THE The following are U.S. patent applications: Series No. __________ (D32630 / 32632) entitled “SAME”; Series No. __________ (D32647) entitled “DISPLAY ARTICLES WITH DIFFRACTIVE, ANTIGLARESURFACES AND THIN, DURABLE ANTIREFLECTION COATINGS”; and Series No. __________ (D32623) entitled “DISPLAY ARTICLES WITH DIFFRACTIVE, ANTIGLARESURFACES AND THIN, DURABLE ANTIREFLECTION COATINGS”. The entire disclosure of each of the aforementioned U.S. patent applications, publications, and patent documents is incorporated herein by reference. Technical Field

[0006] This disclosure relates to a substrate for display articles, wherein the substrate includes a textured region for reducing specular reflectivity, the textured region including a low-refractive-index substrate having a higher elevation surface and a lower elevation surface, and a high-refractive-index material disposed on the lower elevation surface. Background Technology

[0007] A substrate that is transparent to visible light is used to cover displays of display products. Such display products include smartphones, tablets, televisions, computer monitors, and the like. The displays are typically liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, or other similar devices. The substrate protects the display while its transparency allows the user of the device to view it.

[0008] Reflected ambient light, especially from substrates with specular reflection, reduces a user's ability to view a display through the substrate. Specular reflection, in this case, refers to the reflection of ambient light exiting the substrate as if it were a mirror. For example, a substrate can reflect visible light from or emitted by an object into the environment surrounding the device. Visible light reflected from the substrate reduces the contrast of the light transmitted from the display through the substrate to the user's eyes. At certain viewing angles, the user sees a specularly reflected image rather than the visible light emitted by the display. Therefore, efforts have been made to reduce specular reflection of visible ambient light from the substrate.

[0009] Attempts have been made to reduce specular reflection from the substrate by texturing the reflective surface of the substrate. The resulting surface is sometimes called an "anti-glare surface." For example, sandblasting and liquid etching can texturize the surface of the substrate, which typically causes the surface to diffusely reflect ambient light rather than specularly. Diffuse reflection generally means that the surface still reflects the same intensity of ambient light, but the texture of the reflective surface scatters the light during reflection. The more diffuse reflection, the less interference it causes to the user's ability to see the visible light emitted by the display.

[0010] Such texturing methods (i.e., sandblasting and liquid etching) produce features on the surface with imprecise and non-repeatable geometries (these features provide the texture). The geometry of a textured surface on one substrate formed by sandblasting or liquid etching can never be exactly the same as the geometry of a textured surface on another substrate formed by sandblasting or liquid etching. Typically, only the surface roughness (i.e., Rw) of the textured surface of the substrate is considered. a The quantization of ) is a repeatable target for texturing.

[0011] Several metrics exist for judging the quality of an "anti-glare" surface. These metrics include: (1) image sharpness, (2) pixel power deviation, (3) noticeable moiré interference fringes, (4) transmitted haze, (5) specular reduction, and (6) reflected color artifacts. Image sharpness, more appropriately termed reflected image sharpness, is a measure of the sharpness of an image reflected from a surface. The lower the image sharpness, the more diffuse reflection rather than specular reflection occurs on the textured surface. Surface features can amplify the various pixels of a display, distorting the image viewed by the user. Pixel power deviation, also known as "flicker," is a quantification of this effect. Lower pixel power deviation is better. Moiré interference fringes are large-scale interference patterns that, if visible, distort the image seen by the user. Preferably, the textured surface does not produce noticeable moiré interference fringes. Transmitted haze is a measure of how much visible light emitted by the display is diffused by the textured surface as it passes through the substrate. The greater the transmitted haze, the less sharp the display will appear (i.e., a reduced apparent resolution). Specular reduction is a measure of how much a non-anti-glare glass substrate reduces specular reflection of ambient light compared to a baseline. Greater specular reduction compared to the baseline is better. Reflection color artifacts are a type of chromatic aberration where a textured surface diffracts light with varying wavelengths upon reflection, meaning that while the reflected light is relatively diffuse, it appears segmented by color. Less reflection color artifacts produced by a textured surface is better. Some of these properties are discussed in more detail below.

[0012] Targeting only a specific surface roughness cannot simultaneously optimize all of these metrics. The relatively high surface roughness produced by sandblasting or liquid etching may be sufficient to convert specular reflections into diffuse reflections. However, high surface roughness can also result in high transmission haze and pixel power deviation. Relatively low surface roughness, while reducing transmission haze, may not adequately convert specular reflections into diffuse reflections—thus failing to achieve the texturized "anti-glare" purpose.

[0013] Therefore, there is a need for a new method to provide textured regions for substrates—a method that is reproducible between substrates and causes the textured surface to diffusely reflect rather than specularly reflect ambient light to achieve "anti-glare" (e.g., low image sharpness, low specular reflection) but also provides low pixel power deviation, low transmission haze and low reflective color artifacts. Summary of the Invention

[0014] This disclosure provides a novel method for simultaneously delivering multiple desired anti-glare performance metrics. A textured region is formed on the main surface of a substrate, which includes a substrate providing surfaces at two different average elevations, for example, when surface features are etched or otherwise formed into the substrate. A high-refractive-index material is then deposited onto the surface of the substrate located at the lower of the two different average elevations, but not so much that the high-refractive-index material reaches the higher of the two different average elevations of the substrate. Surface features can be placed randomly but specifically to allow reproducibility between substrates. The surface features can have adjustable feature sizes to provide the desired optical results. The presence of the high-refractive-index material generally reduces pixel power bias, and the presence of the surface features effectively scatters light upon reflection, resulting in low specular reflection.

[0015] According to a first aspect of the present disclosure, a substrate for a display article includes: (a) a main surface; and (b) a textured region located on at least a portion of the main surface, the textured region including: (i) one or more higher surfaces located at a higher average elevation, the higher average elevation being parallel to a base plane disposed below the textured region and extending through the substrate; (ii) one or more lower surfaces located at a lower average elevation, the lower average elevation being parallel to the base plane and the lower average elevation being less than the higher average elevation; and (iii) a high refractive index material disposed on each of the one or more lower surfaces located at the lower average elevation, the high refractive index material forming one or more intermediate surfaces located at an intermediate average elevation, the intermediate average elevation being parallel to the base plane and the intermediate average elevation being greater than the lower average elevation but less than the higher average elevation, the high refractive index material comprising a refractive index greater than the refractive index of the substrate or a low refractive index material providing the one or more higher surfaces.

[0016] According to a second aspect of this disclosure, the substrate as described in the first aspect, wherein (i) the intermediate average elevation of the high refractive index material is 100 nm to 190 nm less than the higher average elevation of the one or more higher surfaces; (ii) the lower average elevation of the one or more lower surfaces is 220 nm to 370 nm less than the higher average elevation of the one or more higher surfaces; and (iii) the intermediate average elevation of the high refractive index material is 100 nm to 200 nm greater than the lower average elevation of the one or more lower surfaces.

[0017] According to a third aspect of this disclosure, the substrate as described in any one of the first or second aspects, wherein (i) the refractive index of the substrate or the low-refractive-index material is in the range of 1.4 to 1.6; and (ii) the refractive index of the high-refractive-index material is in the range of 1.6 to 2.3.

[0018] According to a fourth aspect of this disclosure, a substrate as described in any one of the first to third aspects, wherein the high refractive index material occupies 22% to 49% of a region of a plane, the plane (i) being parallel to the base plane and (ii) extending through the high refractive index material, the region being defined by the textured region.

[0019] According to the fifth aspect of this disclosure, the substrate as described in any one of the first to fourth aspects, wherein the substrate comprises a glass substrate or a glass-ceramic substrate.

[0020] According to a sixth aspect of this disclosure, a substrate for a display article comprises: (I) a main surface; and (II) a textured region located on at least a portion of the main surface, the textured region comprising: (a) one or more higher surfaces located at a higher average elevation parallel to a base plane disposed below the textured region and extending through the substrate; (b) one or more lower surfaces located at a lower average elevation parallel to the base plane, the lower average elevation being less than the higher average elevation; and (c) surface features protruding from or disposed within a surrounding portion located on the main surface, wherein (i) the surface features protrude from or are disposed within a surrounding portion located on the main surface. The surface feature provides any one of the following: (i) the one or more higher surfaces or the one or more lower surfaces; (ii) the surrounding portion provides another of the one or more higher surfaces or the one or more lower surfaces, whichever is not provided by the surface feature; and (d) a high refractive index material disposed on one or more lower surfaces at a lower average elevation, the high refractive index material comprising (i) a refractive index greater than the refractive index of the substrate or low refractive index material providing the one or more higher surfaces; and (ii) one or more intermediate surfaces at an intermediate average elevation parallel to the base plane, the intermediate average elevation being between the higher average elevation and the lower average elevation.

[0021] According to a seventh aspect of this disclosure, the substrate as described in the sixth aspect, wherein (i) the surface feature is disposed within the surrounding portion; and (ii) the high refractive index material is disposed within each surface feature, located on one or more lower surfaces provided by the surface features at lower average elevations.

[0022] According to the eighth aspect of this disclosure, the substrate as described in any one of the sixth to seventh aspects, wherein the intermediate average elevation of the high refractive index material is 120 nm to 190 nm smaller than the higher average elevation of the one or more higher surfaces.

[0023] According to the ninth aspect of this disclosure, the substrate as described in any one of the sixth to eighth aspects, wherein the lower average elevation is 220 nm to 370 nm smaller than the higher average elevation.

[0024] According to the tenth aspect of this disclosure, the substrate as described in any one of the sixth to ninth aspects, wherein the intermediate average elevation of the high refractive index material is 100 nm to 200 nm greater than the lower average elevation of the one or more lower surfaces.

[0025] According to the eleventh aspect of this disclosure, the substrate as described in any one of the sixth to tenth aspects, wherein the refractive index of the substrate or low-refractive-index material is in the range of 1.4 to 1.6.

[0026] According to the twelfth aspect of this disclosure, the substrate as described in any one of the sixth to eleventh aspects, wherein the refractive index of the high refractive index material is in the range of 1.6 to 2.3.

[0027] According to the thirteenth aspect of this disclosure, the substrate as described in any one of the sixth to twelfth aspects, wherein (i) each surface feature has a perimeter parallel to the base plane; and (ii) the perimeter of each surface feature is circular or elliptical.

[0028] According to the fourteenth aspect of this disclosure, the substrate described in any one of the sixth to twelfth aspects, wherein (i) each surface feature has a perimeter parallel to the base plane; and (ii) the perimeter of each surface feature has a longest dimension in the range of 5 μm to 200 μm.

[0029] According to the fifteenth aspect of this disclosure, the substrate described in any one of the sixth to fourteenth aspects, wherein the configuration of the surface features is not repetitive but reflects a random distribution.

[0030] According to the sixteenth aspect of this disclosure, the substrate as described in any one of the sixth to fourteenth aspects, wherein the surface features are configured in a random distribution and each of the surface features is separated by a minimum center-to-center distance.

[0031] According to the seventeenth aspect of this disclosure, the substrate as described in any one of the sixth to sixteenth aspects, wherein the high refractive index material comprises AlN x SiO x N y or SiN x .

[0032] According to the eighteenth aspect of this disclosure, the substrate as described in any one of the sixth to seventeenth aspects, wherein the high refractive index material occupies 22% to 49% of a region of a plane, the plane (i) being parallel to the base plane and (ii) extending through the high refractive index material, the region being defined by the textured region.

[0033] According to the nineteenth aspect of this disclosure, the substrate as described in any one of the sixth to eighteenth aspects, wherein the substrate comprises a glass substrate or a glass-ceramic substrate.

[0034] According to the twentieth aspect of this disclosure, the substrate described in any one of the sixth to nineteenth aspects, wherein (i) the textured region exhibits a pixel power deviation in the range of 1.2% to 2.1%; (ii) the textured region exhibits a transmission haze in the range of 1.5% to 2.5%; (iii) the textured region exhibits a specular reflectance in the range of 0.5% to 1.75%; and (iv) the textured region exhibits an image sharpness in the range of 25% to 85%.

[0035] According to a twenty-first aspect of this disclosure, a method for forming a textured region in a substrate for a display article, the method comprising: (a) forming a surface feature protruding from or disposed within a surrounding portion located on a main surface of the substrate at a predetermined position for each surface feature, thereby forming a textured region, wherein (i) one or more higher surfaces of the textured region are located at a higher average elevation, the higher average elevation being parallel to a base plane disposed below the textured region and extending through the substrate; (ii) one or more lower surfaces of the textured region are located at a lower average elevation, the lower average elevation being parallel to the base plane, the lower average elevation being less than the higher average elevation; and (iii) The surface feature provides any one of the following: the one or more higher surfaces or the one or more lower surfaces, and (iv) the surrounding portion provides another of the one or more higher surfaces or the one or more lower surfaces, whichever is not provided by the surface feature; and (b) a high refractive index material is deposited on either the surface feature or the surrounding portion that provides one or more lower surfaces at the lower average elevation, the high refractive index material comprising (i) a refractive index greater than that of the substrate, and (ii) one or more intermediate surfaces at an intermediate average elevation parallel to the base plane, the intermediate average elevation being between the higher average elevation and the lower average elevation.

[0036] According to the twenty-second aspect of this disclosure, the method described in the twenty-first aspect further includes: using a spacing distribution algorithm to determine the position of each surface feature, thereby establishing a predetermined position for each surface feature.

[0037] According to the twenty-third aspect of this disclosure, the method of the twenty-second aspect further comprises: placing an etching mask on the main surface, the etching mask either (i) preventing etching of the area where a surface feature is to be formed according to a predetermined location of the surface feature or (ii) allowing etching only of the area where a surface feature is to be formed according to a predetermined location of the surface feature; wherein forming the surface feature includes, when the etching mask is placed on the main surface of the substrate, contacting the etchant at least with the main surface of the substrate.

[0038] According to the twenty-fourth aspect of this disclosure, the method described in the twenty-third aspect, wherein the high refractive index material is deposited when the etch mask is placed on the main surface and after the surface features have been formed.

[0039] According to the twenty-fifth aspect of this disclosure, the method described in the twenty-fourth aspect further comprises: removing the etch mask after the high refractive index material has been deposited. Attached Figure Description

[0040] In the attached diagram:

[0041] Figure 1 This is a perspective view of a display article of the present disclosure, illustrating a substrate having textured regions for reducing the specular reflectivity of light emitted from the external environment;

[0042] Figure 2 It is an optical profilometer scan, which is related to Examples 2A-2G and also generally illustrates an implementation of a textured region comprising one or more surfaces located at a higher average elevation from the base plane and a high refractive index material disposed within the surface features, the high refractive index material forming a surface located at a middle average elevation from the base plane;

[0043] Figure 3A Is it through Figure 2 An elevation view of a section taken by line III-III, illustrating a substrate having a surface at a higher average elevation, a surface at a lower average elevation from the base plane, and a high refractive index material disposed on the surface at the lower average elevation, the high refractive index material having a surface at an intermediate average elevation between the higher average elevation and the lower higher average elevation.

[0044] Figure 3B Is with Figure 3A The same view, but illustrating that the surface features are not situated within the surrounding portion of the substrate (e.g.) Figure 3A (Instead of that) it is a scenario where the surrounding part protrudes and a high-refractive-index material is placed on the surrounding part;

[0045] Figure 4 This is an example diagram illustrating the calculation of hexagonal percentages;

[0046] Figure 5 It is formed Figure 1 A schematic diagram illustrating a method for implementing a textured region, the schematic diagram illustrating the following steps: determining the location of a surface feature, placing an etch mask on a substrate to form a surface feature at the determined location, forming a surface feature by etching while the etch mask is on the substrate, depositing a high refractive index material onto the substrate while the etch mask is still on the substrate, and then removing the etch mask.

[0047] Figure 6A The graph relating to Comparative Example 1A illustrates how the diffraction efficiency of transmitted light through the textured region of the substrate varies with the trench depth (i.e., the distance between the higher and lower average elevations).

[0048] Figure 6B This is a graph related to Comparative Example 1A, illustrating how the diffraction efficiency of light reflected from the textured region of the substrate varies with the trench depth.

[0049] Figure 7A This is a graph related to Example 1B, illustrating how the diffraction efficiency of transmitted light through the textured region of the substrate varies with the trench depth.

[0050] Figure 7B This is a graph related to Example 1B, illustrating how the diffraction efficiency of light reflected from the textured region of the substrate varies with the trench depth.

[0051] Figure 7C The graph relating to Example 1B illustrates how the diffraction efficiency of transmitted light through the textured region of the substrate varies with the substrate fill fraction (i.e., the percentage of the plane of high-refractive-index material that the substrate occupies through the textured region).

[0052] Figure 7D The graph relating to Example 1B illustrates how the diffraction efficiency of light reflected from the textured region of the substrate varies with the fill fraction of the substrate (i.e., the percentage of the plane of high-refractive-index material that the substrate occupies through the textured region).

[0053] Figure 7E This is a graph related to Example 1B, illustrating how the diffraction efficiency of transmitted light passing through a textured region of a substrate varies with the incident light angle.

[0054] Figure 7F This is a graph related to Example 1B, illustrating how the diffraction efficiency of light reflected from a textured region of a substrate varies with the angle of incident light.

[0055] Figure 8 This is a histogram related to Examples 2A-2G, illustrating the center-to-center distance of objects randomly placed in a region (to allocate the placement of surface features in the subsequently formed textured region) via a spacing distribution algorithm; and

[0056] Figure 9It is a histogram related to Embodiment 3A-3D, which illustrates the center-to-center distance of an object randomly placed in a region (in order to assign the placement of surface features of the subsequently formed textured region) via another spacing distribution algorithm. Detailed Implementation

[0057] Now for reference Figure 1 The display article 10 includes a substrate 12. In one embodiment, the display article 10 further includes a housing 14 to which the substrate 12 is connected; and a display 16 located within the housing 14. In such embodiments, the substrate 12 at least partially covers the display 16 such that light emitted from the display 16 is transmitted through the substrate 12.

[0058] The substrate 12 includes a main surface 18, a textured region 20 defined on the main surface 18, and a thickness 22 partially defined by the main surface 18. The main surface 18 generally faces the external environment 24 surrounding the display article 10 and faces away from the display 16. The display 16 emits visible light that is transmitted through the thickness 22 of the substrate 12, exits the main surface 18, and enters the external environment 24.

[0059] Now for reference Figure 2-3B In one embodiment, the textured region 20 includes one or more higher surfaces 26 facing the external environment 24 and located at a higher average elevation 28. A base plane 30 extends below the textured region 20 through the substrate 12. The higher average elevation 28 is parallel to the base plane 28. The base plane 30 provides a conceptual reference point and is not a structural feature. Within manufacturing capabilities, each of the one or more higher surfaces 26 is located approximately at the higher average elevation 28.

[0060] The textured region further includes one or more lower surfaces 32 facing the external environment 24 and located at a lower average elevation 34. The lower average elevation 34 is parallel to the base plane 28 and is lower than the higher average elevation 28. Therefore, "higher" and "lower" are relative elevations relative to each other from the base plane 28. Within manufacturing capabilities, each of the one or more lower surfaces 32 is located approximately at the lower average elevation 34.

[0061] Substrate 12 or a low-refractive-index material disposed on substrate 12 provides one or more higher surfaces 26 for the textured region 20. In such embodiments, either substrate 12 or the low-refractive-index material providing one or more higher surfaces 26 has a refractive index of 1.4, 1.5, 1.6, or in the range of 1.4 to 1.6. In embodiments, substrate 12, regardless of whether it provides one or more higher surfaces 26, has a refractive index of 1.4, 1.5, 1.6, or in the range of 1.4 to 1.6. For the purposes of this disclosure, any specific value of the refractive index is relative to a wavelength of 589 nm and a temperature of 25°C.

[0062] The textured region 20 further comprises a high-refractive-index material 36. In an embodiment, the high-refractive-index material 36 has a composition different from that of the substrate 12. The high-refractive-index material 36 is disposed on each of one or more lower surfaces 32 of the textured region 20 located at a lower average elevation 34. The high-refractive-index material 36 forms one or more intermediate surfaces 38 facing the external environment 24 and located at an intermediate average elevation 40 parallel to the base plane 30. Within manufacturing capabilities, each of the one or more intermediate surfaces 38 is located approximately at an intermediate average elevation 40.

[0063] The high-refractive-index material 36 has a refractive index. The refractive index of the high-refractive-index material 36 is greater than the refractive index of the substrate 12. In an embodiment, the refractive index of the high-refractive-index material 36 is 1.6, 1.7, 1.8, 1.9, 2.0, 2.01, 2.02, 2.03, 2.04, 2.05, 2.06, 2.07, 2.08, 2.09, 2.1, 2.2, 2.3, or within any range defined by any two of these values ​​(e.g., 1.6 to 2.3, 1.8 to 2.2, 1.9 to 2.1, etc.). In an embodiment, the high-refractive-index material is or comprises Si. u Al v O x N y Ta2O5, Nb2O5, AlN x Si3N4, AlO x N y SiO x N y SiN x SiN x :H y HfO2, TiO2, ZrO2, Y2O3, Al2O3, MoO3, and diamond-like carbon. In embodiments, the high refractive index material is or contains AlN. x SiO x N y or SiN x In this embodiment, the high refractive index material is or contains AlN. x Regarding "AlN" in this disclosure x “AlO” x N y "SiO" x N y "and "SiN x"Materials," the subscript allows those skilled in the art to refer to these materials as a class of materials without specifying a particular subscript value. The oxygen-nitrogen ratio can be adjusted via conventional experiments used to adjust the refractive index of high-refractive-index materials. For embodiments requiring high film refractive indices (e.g., greater than 1.8 or 1.9), SiN having a composition close to Si3N4 is preferred. x This can be preferred. For films with similar high refractive indices, AlN with a composition close to that of AlN is preferred. x Alternatively, a small fraction of oxygen or hydrogen (e.g., 0-20 atomic percent) can also be incorporated into these materials, while achieving a similar high refractive index range.

[0064] The intermediate average elevation 40 of one or more intermediate surfaces 38 of the high refractive index material 36 is greater than the lower average elevation 34 of one or more lower surfaces 32 of the textured region 20, but less than the higher average elevation 28 of one or more higher surfaces 26 of the textured region 20. In short, the intermediate average elevation 40 lies between the higher average elevation 28 and the lower average elevation 34.

[0065] The higher average elevation 28 of one or more higher surfaces 26 of the textured region 20 is greater than the lower average elevation 34 of one or more lower surfaces 32 of the textured region 20 by a distance 42. This disclosure may refer to the distance 42 as a “trench depth” (not to be confused with “air trench depth” discussed later). In embodiments, the distance 42 is 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, or 370 nm, or any range defined by any two of these values ​​(e.g., 250 nm to 350 nm, 270 nm to 330 nm, 220 nm to 370 nm, etc.).

[0066] The intermediate average elevation 40 of the high refractive index material 36 is greater than the lower average elevation 34 of one or more lower surfaces 32 of the textured region 20 by a distance 44. Distance 44 may be referred to as the “height” or “thickness” of the high refractive index material 36 deposited on one or more lower surfaces 32. In embodiments, distance 44 is 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, or 200 nm, or any range defined by any two of these values ​​(e.g., 100 nm to 200 nm, 120 nm to 180 nm, etc.).

[0067] The intermediate average elevation 40 of the high refractive index material 36 is a smaller distance 46 than the higher average elevation 28 of one or more higher surfaces 26 of the textured region 20. This distance 46 may be referred to herein as the “air trench depth”. In embodiments, the distance 46 is 100 nm, 110 nm, 120 nm, 125 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, or 190 nm, or any range defined by any two of these values ​​(e.g., 120 nm to 190 nm, 125 nm to 190 nm, 130 nm to 180 nm, 100 nm to 190 nm, etc.). Note that... Figure 3A and Figure 3B It was not drawn to scale.

[0068] The high-refractive-index material 36 occupies a certain percentage of region 48 of plane 50, which (i) is parallel to the base plane 30 and (ii) extends through the high-refractive-index material 36. Region 48 is defined by textured region 20. In other words, region 48 does not extend laterally beyond textured region 20. The percentage of region 48 of plane 50 occupied by the high-refractive-index material 36 may be referred to herein as the “fill fraction” of the high-refractive-index material 36. In embodiments, the fill fraction of the high-refractive-index material 36 is 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, or 49%, or within any range defined by any two of these values ​​(e.g., 44% to 45%, 22% to 49%, etc.). 100% minus the fill fraction of the high-refractive-index material 36 is the fill fraction of the substrate 12 or a low-refractive-index material deposited on the substrate 12 that has a lower refractive index compared to the high-refractive-index material 36.

[0069] It is believed that when the filling fraction of the high-refractive-index material is between 22% and 49%, the specular reflectivity and the intensity of the first-order diffraction peak are minimized. The high-refractive-index material 36, with a higher refractive index than the substrate 12 or the low-refractive-index material, exhibits stronger reflectivity. Therefore, to maximize destructive interference during reflection, the high-refractive-index material 36 should occupy less than half of the textured region 20 on the main surface 18 reflecting ambient light. More than half of the textured region 20 on the main surface 18 reflecting ambient light should be the substrate 12 or the low-refractive-index material with a lower refractive index to balance the stronger reflectivity of the high-refractive-index material 36.

[0070] In one embodiment, the textured region 20 includes surface features 52. In another embodiment, the surface features 52 protrude from the surrounding portion 54 of the textured region 20 at the surface 18. Such surface features 52 may take the form of pillars, ridges, or the like. In another embodiment, the surface features 52 are disposed within the surrounding portion 54 (i.e., disposed within the surrounding portion 54). Such surface features 52 may take the form of blind holes, channels, or mesas extending from the surrounding portion 54 into the thickness 22 of the substrate 12 or a low-refractive-index material. In another embodiment, some of the surface features 52 are disposed within the surrounding portion 54, while others protrude from the surrounding portion 54. In another embodiment, the surrounding portion 54 adjacently surrounds the surface features 52.

[0071] Surface feature 52 or either of the surrounding portion 54 provides one or more higher surfaces 26 located at a higher average elevation 28, while the other of surface feature 52 and the surrounding portion 54 provides one or more lower surfaces 32 located at a lower average elevation 34. When surface feature 52 protrudes from the surrounding portion 54 (see...) Figure 3A When surface feature 52 is located at a higher average elevation 28, one or more higher surfaces 26 are provided. In such cases, one or more lower surfaces 32 are provided around portion 54 at a lower average elevation 34. When surface feature 52 is disposed within portion 54 (see...), Figure 3B When ), one or more higher surfaces 26 are provided around portion 54 at a higher average elevation 28. In such cases, surface feature 52 provides one or more lower surfaces 32 at a lower average elevation 34.

[0072] A high-refractive-index material 36 is disposed on either a surface feature 52 or a surrounding portion 64 providing one or more lower surfaces 32 at a lower average elevation 34. In an embodiment where the surface feature 52 is disposed within the surrounding portion 54, the high-refractive-index material 36 is disposed within the surface feature 52 on one or more lower surfaces 32 provided by the surface feature 52 at a lower average elevation 34. In an embodiment where the surface feature 52 protrudes from the surrounding portion 54, the high-refractive-index material 36 is disposed between the surface features 52 on one or more lower surfaces 32 provided by the surrounding portion 54 at a lower average elevation 34. In an embodiment where the high-refractive-index material 36 is disposed on the surrounding portion 54 and the surrounding portion 54 is adjacent, the high-refractive-index material 36 may form a surface intermediate 38 surrounding and adjacent to the surface feature 52 protruding through the high-refractive-index material 36 toward the external environment 24.

[0073] In one embodiment, one or more higher surfaces 26 located at a higher average elevation 28 are planar. In another embodiment, one or more lower surfaces 32 located at a lower average elevation 34 are planar. In other embodiments, one or more lower surfaces 32 are convex or concave. In one embodiment, some of the lower surfaces 32 are concave, while others are convex.

[0074] The textured region 20, providing one or more higher surfaces 26 at a higher average elevation 28 and one or more lower surfaces 32 at a lower average elevation 34, is a diffraction structure that induces controlled scattering of reflected ambient light. The scattering of reflected ambient light reduces specular reflectivity and image sharpness. As will be further shown, the high refractive index material 36, having a refractive index greater than that of the substrate 12 or the low refractive index material on the substrate 12, improves light transmission through the textured region 20 (such as from the display 16), reducing transmission haze and pixel power deviation compared to using only the textured region 20 without utilizing the high refractive index material 36.

[0075] In some embodiments, surface features 52 are arranged in a random distribution. In other words, in these embodiments, surface features 52 are not arranged in a pattern. However, in other embodiments, surface features 52 are arranged in a pattern, such as a hexagonal arrangement. When surface features 52 are arranged in a pattern, the textured regions 20 can produce moiré fringe interference patterns when reflecting ambient light. Furthermore, not arranging surface features 52 in a pattern reduces the wavelength dependence of the scattered ambient light. Therefore, for some applications, avoiding a patterned arrangement of surface features 52 can be advantageous.

[0076] refer to Figure 4 One measure of randomness is the hexagonal percentage of surface feature 52. The hexagonal percentage is a measure of how closely objects are arranged in a locally quantifiable region to form a hexagonal lattice. Each object in the region has a center point. For each center point in the region, the hexagonal percentage H at that center point is calculated according to the following equation using the angles of the six nearest neighboring center points relative to an arbitrary axis.

[0077]

[0078] variable α kLet H represent the angles of the six nearest neighbor center points. For a hexagonal lattice, all six angles differ by 60 degrees (π / 3 radians), therefore the exponents of the six addends differ by 2π radians, and all six complex numbers in the summation are identical. In this case, H = 1, a perfect hexagonal lattice. Each center point within this region has its unique H value. The mean of all H values ​​within this region represents the deviation of the configuration from the hexagonal lattice. The further the mean of all H values ​​deviates from 1, the more random the configuration.

[0079] Each surface feature 52 has a perimeter 56 parallel to the base plane 30. In an embodiment, the perimeter 56 of each surface 52 has the same shape. For example, in an embodiment, for instance... Figure 2 In the illustrated embodiments, the perimeter 56 of each surface feature 52 is circular. In some embodiments, the perimeter 56 of each surface feature 52 is elliptical. In some embodiments, the perimeter 56 of each surface feature 52 is hexagonal or polygonal. In some embodiments, the perimeter 56 of the surface feature 52 is one of two or more shapes (e.g., some are elliptical and some are circular).

[0080] Each surface feature 52 has a perimeter 56 with a longest dimension 58. If the perimeter 52 is circular, the longest dimension 58 is the diameter of the perimeter 56. If the perimeter 56 is hexagonal, the longest dimension 58 is the major axis (long diagonal). And so on. In an embodiment, the longest dimension 58 of the perimeter 56 of each surface feature 52 is 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, or 200 μm, or any range defined by any two of these values ​​(e.g., 5 μm to 200 μm, 20 μm to 100 μm, 80 μm to 120 μm, 30 μm to 70 μm, 25 μm to 75 μm, etc.).

[0081] In an embodiment, a minimum center-to-center distance 60 separates surface features 52. For example, if the minimum center-to-center distance 60 is 100 μm, the center of one surface feature 52 may be separated from the center of another adjacent surface feature 52 by 100 μm or more, but not less than 100 μm. In an embodiment, the minimum center-to-center distance 60 is 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, or 130 μm, or any range defined by any two of these values ​​(e.g., 30 μm to 70 μm, 40 μm to 80 μm, 5 μm to 100 μm, 20 μm to 90 μm, 30 μm to 80 μm, etc.).

[0082] The high-refractive-index material 36, having a refractive index greater than that of the substrate 12 or the low-refractive-index material on the substrate 12, reduces the pixel power deviation generated by the textured region 20. This allows the minimum center-to-center spacing 60 to be greater than the spacing that would be possible without the high-refractive-index material 36. Furthermore, the incorporation of the high-refractive-index material 36 allows the surface feature 52 to have a longer maximum dimension 58 than would be possible without it. This is advantageous for several reasons. First, the longer the maximum dimension 58 of the surface feature 52, the easier it is to manufacture the surface feature 52 and thus the textured region 20. With the high-refractive-index material 36 incorporated, the textured region 20 can be manufactured using low-cost methods such as inkjet printing, screen printing, or gravure offset printing. Second, the longer the maximum dimension 58 of the perimeter 56 of the surface feature 52, the less transmission haze is generated by the textured region 20. However, there is a practical limitation on the longest dimension 58 of the surface feature 52, because if the longest dimension 58 is long enough, the surface feature 52 becomes visible to the human eye, which may be undesirable.

[0083] Third, when the longest dimension 58 of the perimeter 56 of surface feature 52 is sufficiently long, surface feature 52 scatters more intense reflected light within a narrow angular range (including close to 0.3 degrees) with respect to the specular angle. This results in higher pixel power deviation in the textured region 20. Additionally, this leads to fewer reflected color artifacts because the reflected light is not scattered within a sufficiently wide angular range that allows the human eye to distinguish between colors. For example, the angular spacing between the peak scattering angles of the 450nm wavelength portion and the 650nm wavelength portion of light can be less than 0.4 degrees, less than 0.3 degrees, or even less than 0.2 degrees. Smaller angular spacing between different wavelengths is preferred because the human eye has difficulty distinguishing extremely small angular spacings; therefore, with small scattering angular spacing between wavelengths, fewer colors of scattered light are visible to the observer.

[0084] In some embodiments, the substrate 12 comprises glass or glass-ceramic. In others, the substrate 12 is a multi-component glass composition having about 40 mol% to 80 mol% silicon dioxide and one or more other components, such as alumina, calcium oxide, sodium oxide, boron oxide, etc., as the balance. In some embodiments, the bulk composition of the substrate 12 is selected from the group consisting of aluminosilicate glass, borosilicate glass, and phosphosilicate glass. In other embodiments, the bulk composition of the substrate 12 is selected from the group consisting of aluminosilicate glass, borosilicate glass, phosphosilicate glass, soda-lime glass, alkaline aluminosilicate glass, and alkaline aluminoborosilicate glass. In still others, the substrate 12 is a glass-based substrate, including but not limited to glass-ceramic materials comprising about 90% by weight or more of a glass component and a ceramic component. In other embodiments of the display article 10, the substrate 12 may be a polymer material having durability and mechanical properties suitable for the development and retention of the textured region 20. In other embodiments, the substrate 12 is or comprises a single-crystal structure, such as sapphire.

[0085] In one embodiment, the substrate 12 has a bulk composition comprising an alkaline aluminosilicate glass comprising alumina, at least one alkali metal, and in some embodiments greater than 50 mol% SiO2, in other embodiments at least 58 mol% SiO2, and in still other embodiments at least 60 mol% SiO2, wherein the ratio (Al2O3(mol%) + B2O3(mol%)) / ∑alkali metal modifier(mol%) > 1, wherein the modifier is an alkali metal oxide. In a specific embodiment, the glass comprises, substantially comprises, or comprises the following: about 58 mol% to about 72 mol% SiO2; about 9 mol% to about 17 mol% Al2O3; about 2 mol% to about 12 mol% B2O3; about 8 mol% to about 16 mol% Na2O; and 0 mol% to about 4 mol% K2O, wherein the ratio (Al2O3 (mol%) + B2O3 (mol%)) / ∑ alkali metal modifier (mol%) > 1, wherein the modifier is an alkali metal oxide.

[0086] In an embodiment, the substrate 12 has a bulk composition comprising an alkaline aluminosilicate glass comprising, substantially comprising, or comprising the following: about 61 mol% to about 75 mol% SiO2; about 7 mol% to about 15 mol% Al2O3; 0 mol% to about 12 mol% B2O3; about 9 mol% to about 21 mol% Na2O; 0 mol% to about 4 mol% K2O; 0 mol% to about 7 mol% MgO; and 0 mol% to about 3 mol% CaO.

[0087] In an embodiment, the substrate 12 has a bulk composition comprising an alkaline aluminosilicate glass, which comprises, substantially comprises, or comprises the following: about 60 mol% to about 70 mol% SiO2; about 6 mol% to about 14 mol% Al2O3; 0 mol% to about 15 mol% B2O3; 0 mol% to about 15 mol% Li2O; 0 mol% to about 20 mol% Na2O; 0 mol% to about 10 mol% K2O; 0 mol% to about 8 mol% MgO; 0 mol% to about 10 mol% CaO; 0 mol% to about 5 mol% ZrO2; 0 mol% to about 1 mol% SnO2; 0 mol% to about 1 mol% CeO2; less than about 50 ppm As2O3; and less than about 50 ppm Sb₂O₃; wherein 12 mol% ≦ Li₂O + Na₂O + K₂O ≦ 20 mol% and 0 mol% ≦ MgO + Ca ≦ 10 mol%.

[0088] In an embodiment, the substrate 12 has a bulk composition comprising an alkaline aluminosilicate glass, which comprises, is substantially composed of, or is composed of: about 64 mol% to about 68 mol% SiO2; about 12 mol% to about 16 mol% Na2O; about 8 mol% to about 12 mol% Al2O3; 0 mol% to about 3 mol% B2O3; 2 mol% to about 5 mol% K2O; 4 mol% to about 6 mol% MgO; and 0 mol%... The concentration of CaO is approximately 5 mol%, wherein: 66 mol% ≤ SiO2+B2O3+CaO ≤ 69 mol%; Na2O+K2O+B2O3+MgO+CaO+SrO > 10 mol%; 5 mol% ≤ MgO+CaO+SrO ≤ 8 mol%; (Na2O+B2O3)—Al2O3 ≤ 2 mol%; 2 mol% ≤ Na2O—Al2O3 ≤ 6 mol%; and 4 mol% ≤ (Na2O+K2O)—Al2O3 ≤ 10 mol%.

[0089] In one embodiment, the substrate 12 has a bulk composition comprising SiO2, Al2O3, P2O5, and at least one alkali metal oxide (R2O), wherein 0.75 > [(P2O5(mol%) + R2O(mol%)) / M2O3(mol%)] ≤ 1.2, and M2O3 = Al2O3 + B2O3. In another embodiment, [(P2O5(mol%) + R2O(mol%)) / M2O3(mol%)] = 1. In yet another embodiment, the glass does not contain B2O3, and M2O3 = Al2O3. In yet another embodiment, the substrate 12 comprises: about 40 mol% to about 70 mol% SiO2; 0 mol% to about 28 mol% B2O3; about 0 mol% to about 28 mol% Al2O3; about 1 mol% to about 14 mol% P2O5; and about 12 mol% to about 16 mol% R2O. In some embodiments, the glass substrate comprises: about 40 mol% to about 64 mol% SiO2; 0 mol% to about 8 mol% B2O3; about 16 mol% to about 28 mol% Al2O3; about 2 mol% to about 12 mol% P2O5; and about 12 mol% to about 16 mol% R2O. The substrate 12 may further comprise at least one alkaline earth metal oxide, such as, but not limited to, MgO or CaO.

[0090] In some embodiments, the substrate 12 has a substantially lithium-free bulk composition; that is, the glass contains less than 1 mol% Li₂O, in other embodiments less than 0.1 mol% Li₂O, in other embodiments 0.01 mol% Li₂O, and in other embodiments 0 mol% Li₂O. In some embodiments, such glass is free of at least one of arsenic, antimony, and barium; that is, the glass contains less than 1 mol% As₂O₃, Sb₂O₃, and / or BaO, in other embodiments less than 0.1 mol% As₂O₃, Sb₂O₃, and / or BaO, and in other embodiments 0 mol% As₂O₃, Sb₂O₃, and / or BaO.

[0091] In an embodiment, the substrate 12 has a body composition comprising, substantially composed of, or composed of a glass composition, such as... Eagle Glass, Glass, Glass 2 Glass 3 Glass 4 or Glass 5.

[0092] In one embodiment, the substrate 12 has an ion-exchangeable glass composition strengthened by chemical or thermal means known in the art. In another embodiment, the substrate 12 is strengthened by ion-exchange chemistry. In this process, metal ions at or near the main surface 18 of the substrate 12 are exchanged for larger metal ions with the same valence as the metal ions in the substrate 12. The exchange is typically carried out by contacting the substrate 12 with an ion-exchange medium (such as, for example, a molten salt bath containing larger metal ions). The metal ions are typically monovalent metal ions, such as, for example, alkali metal ions. In a non-limiting example, strengthening the substrate 12 containing sodium ions by ion-exchange chemistry is accomplished by immersing the substrate 12 in an ion-exchange bath containing molten potassium salts (e.g., potassium nitrate (KNO3)). In a specific embodiment, the ions and larger ions in the surface layer of the substrate 12 adjacent to the main surface 18 are monovalent alkali metal cations, such as Li. + (when present in glass), Na + K + 、Rb + and Cs + Alternatively, the monovalent cations in the surface layer of substrate 12 can be monovalent cations other than alkali metal cations, such as Ag. + Or a similar alternative.

[0093] In such embodiments, during ion exchange, larger metal ions replace smaller metal ions, creating a compressive stress region in the substrate 12 that extends to a certain depth (referred to as the "layer depth") on the self-surface 18 and is under compressive stress. This compressive stress in the substrate 12 is balanced by tensile stress (also referred to as "central tension") within the substrate 12. In some embodiments, when strengthened by ion exchange, the main surface 18 of the substrate 12 described herein has a compressive stress of at least 350 MPa, and the region under compressive stress extends to a depth of at least 15 μm below the main surface 18 into the thickness 22, i.e., the layer depth.

[0094] Ion exchange processes are typically carried out by immersing the substrate 12 in a molten salt bath containing larger ions to be exchanged with smaller ions in the glass. Those skilled in the art will understand that the parameters of the ion exchange process are typically determined by the glass composition, the desired layer depth, and the compressive stress of the glass as a result of the strengthening operation. These parameters include, but are not limited to, bath composition and temperature, immersion time, the number of immersions of the glass in the salt bath (or multiple baths), the use of various salt baths, and additional steps such as annealing and washing. For example, ion exchange of alkali metal glasses can be achieved by immersion in at least one molten bath containing salts such as, but not limited to, nitrates, sulfates, and chlorides containing larger alkali metal ions. The temperature of the molten salt bath is typically in the range of about 380°C to up to about 450°C, and the immersion time ranges from about 15 minutes to up to about 16 hours. However, temperatures and immersion times different from those described above may also be used. When this type of ion exchange treatment is used together with a substrate 12 having an alkaline aluminosilicate glass composition, a compressive stress region is generated, which has a depth (layer depth) ranging from about 10 μm to at least 50 μm and a compressive stress ranging from about 200 MPa to at least about 800 MPa and a center tension of less than about 100 MPa.

[0095] The etching process can be used to create the textured region 20 of the substrate 12. Since the etching process can remove alkali metal ions from the substrate 12 that would otherwise be replaced by larger alkali metal ions during the ion exchange process, it is preferable to form a compressive stress region in the display article 10 after the textured region 20 is formed and developed.

[0096] In this implementation, the textured region 20 exhibits pixel power deviation (“PPD”). Details of the measurement system and image processing calculations used to obtain the PPD value are described in U.S. Patent No. 9,411,180, entitled “Apparatus and Method for Determining Sparkle,” the prominent portions of which are related to PPD measurement are incorporated herein by reference in their entirety. Furthermore, unless otherwise indicated, the SMS-1000 system (Display-Messtechnik & Systeme) is used to generate and evaluate the PPD measurements of this disclosure. The PPD measurement system includes: a pixelation source comprising a plurality of pixels (e.g., a Lenovo Z50 140ppi notebook computer), each of the plurality of pixels having reference indices i and j; and an imaging system optically positioned along an optical path originating from the pixelation source. The imaging system includes: an imaging device disposed along an optical path and having a pixelated sensitive region comprising a second plurality of pixels, each of which is referenced by indices m and n; and a diaphragm disposed on the optical path between the pixelation source and the imaging device, wherein the diaphragm has an adjustable collection angle for an image originating from the pixelation source. Image processing calculations include: acquiring a pixelated image of a transparent sample, the pixelated image comprising a plurality of pixels; determining the boundaries between adjacent pixels in the pixelated image; performing integration within the boundaries to obtain the integrated energy of each source pixel in the pixelated image; and calculating the standard deviation of the integrated energy of each source pixel, wherein the standard deviation is the power of dispersion per pixel. As used herein, all PPD values, properties, and limits are calculated and evaluated using a testing apparatus employing a display device with a pixel density of 140 pixels per inch (PPI). In embodiments, the PPD exhibited by the display article 10 is 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, or within any range defined by any two of these values ​​(e.g., 1.2% to 2.1%, etc.). In embodiments, the PPD exhibited by the textured region 20 is less than 4%, less than 3%, less than 2.5%, less than 2.1%, less than 2.0%, less than 1.75%, or even less than 1.5%.

[0097] The textured region 20 of this disclosure produces such a low pixel power deviation, meaning that the display 16 of the display article 10 can have a higher resolution than normal. As mentioned in the preceding paragraphs, the pixel power deviation value is determined using an industry-standard display with a resolution of 140 pixels per inch (“ppi”). The textured region 20 of this disclosure can transmit this resolution with low pixel power deviation. Therefore, the resolution of the display 16 can be increased. In embodiments, the display 16 of the display article 10 has a resolution greater than 140 ppi, such as a resolution in the range of 140 ppi to 300 ppi.

[0098] In this implementation, the textured region 20 exhibits image sharpness (“DOI”). As used herein, “DOI” equals 100*(R S -R 0.3° ) / R S , where R S R is the specular reflectivity flux of the incident light (at an angle of 20° with the normal) directed to the textured region 20, and R 0.3 The flux R of the same incident light at 0.3° is based on the specular reflectivity. S The measured reflectance flux. Unless otherwise stated, the DOI values ​​and measurements reported in this disclosure are obtained according to ASTM D5767-18 entitled "Standard Test Method for Instrumental Measurement of Distinctness-of-Image (DOI) Gloss of Coated Surfaces using a Rhopoint IQ Gloss Haze & DOI Meter" [Rhopoint Instruments Ltd.]. Furthermore, the DOI measurements are performed while the back surface of substrate 12 (the side opposite to the main surface 18) is coupled to the absorber to remove reflections departing from the back surface. Therefore, the DOI value here is a "coupled" or "first surface" value. In one embodiment, the image sharpness (“DOI”) exhibited by the textured region 20 is 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85%, or within any range defined by any two of these values ​​(e.g., 25% to 85%, etc.). In another embodiment, the image sharpness exhibited by the textured region 20 is less than 90%, less than 80%, less than 70%, less than 60%, less than 50%, less than 40%, less than 35%, or even less than 30%.

[0099] In this implementation, the textured region 20 exhibits transmitted haze. As used herein, the term "transmitted haze" refers to the percentage of transmitted light scattered beyond a pyramid of approximately ±2.5°, according to ASTM D1003, entitled "Sandard Test Method for Haze and Luminous Transmittance of Transparent Plastics," the entire contents of which are incorporated herein by reference. In this example, transmitted haze was measured using a BYK Gardner HAZE-GARD Plus instrument, with the incident light at perpendicular incidence (zero degrees) and measured using an integrating sphere detector system. Note that although the title of ASTM D1003 refers to plastics, the standard also applies to substrates containing glass materials. For optically smooth surfaces, transmitted haze is typically close to zero. In embodiments, the transmission haze exhibited by the textured region 20 is 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, or 2.5%, or within any range defined by any two of these values ​​(e.g., 1.5% to 2.5%, etc.). In embodiments, the transmission haze exhibited by the textured region 20 is less than 20%, less than 10%, less than 5%, less than 3%, less than 2.5%, or even less than 2.0%.

[0100] In this embodiment, the specular reflectance exhibited by the textured region 20 is 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.75%, or within any range defined by any two of these values ​​(e.g., 0.5% to 1.75%, etc.). The specular reflectance herein was determined using a Rhopoint IQ Gloss Haze & DOI meter (Robert Instruments Ltd.) at a 20-degree incident angle of reflection and coupled to an absorber on the back surface of substrate 12 to remove back surface reflections. The values ​​reported by this instrument are in gloss units (GU) normalized to 100 GU for a black glass control sample with a known primary surface reflectance value of 4.91% and a refractive index of 1.567 at a 20-degree incident angle. Therefore, the specular reflectance value mentioned here represents the absolute first surface specular reflectance (percentage) converted from the instrument-generated value by multiplying it by 0.0491 according to the equation.

[0101] In an embodiment, the textured region 20 exhibits transmittance of 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, or 95% or within any range defined by any two of these values ​​(e.g., 85% to 95%, 90% to 92%, etc.). As used herein, the term "transmittance" is defined as the percentage of incident light power transmitted through the substrate 12 and exiting the textured region 20 within a given wavelength range. In this example, transmittance is measured using a BYK Gardner HAZE-GARD Plus instrument with incident light at perpendicular incidence (0 degrees) and an integrating sphere detector system. The reported transmittance is the total transmittance over all output angles.

[0102] In the implementation, the textured region 20 simultaneously exhibits: (i) a pixel power deviation in the range of 1.2% to 2.1%, (ii) a transmission haze in the range of 1.5% to 2.5%, (iii) a specular reflectance in the range of 0.5% to 1.75%, and (iv) an image sharpness in the range of 25% to 85%.

[0103] Now for reference Figure 5 This document describes a method 100 for forming a textured region 20. At step 102, method 100 includes forming a surface feature 52 protruding from or disposed within a surrounding portion at a predetermined location on a main surface 18 of a substrate 12. At step 104, method 100 further includes depositing a high-refractive-index material 36 on the surface feature 52 or surrounding portion 54 providing one or more lower surfaces 32 located at a lower average elevation 34. Steps 102 and 104 will be discussed further below.

[0104] In one implementation, at step 106, method 100 further includes determining the position of each surface feature 52 using a spacing distribution algorithm. The result is a predetermined position for each of the aforementioned surface features 52. This step 106 is performed prior to step 102, which forms the surface features 52 into the substrate 12. Exemplary spacing distribution algorithms include Poisson disk sampling, maximum-minimum spacing, and hard sphere distribution. The spacing distribution algorithm places objects 108 (representing surface features 52, or from which the placement of surface features 52 can be derived) on regions 110 that match the desired minimum center-to-center distance 60 for each surface feature 52, based on a minimum center-to-center distance 112 separating each object 108.

[0105] The Poisson disk sampling inserts a first object 108 (circular, with a diameter equal to the longest dimension 58 required by the matching surface feature 52) into region 48. The algorithm then inserts a second object 108 into region 48, centering it at a random point within region 48. If the placement of the second object 108 satisfies a minimum center-to-center distance 112 from the first object 108, then the second object 108 remains in region 48. The algorithm then repeats this process until no more objects 180 can be placed within region 110 satisfying the minimum center-to-center distance 112. The result is a randomly distributed but specific placement of objects 108.

[0106] The max-min gap algorithm is so named because it attempts to maximize the minimum nearest neighbor center-to-center distance of a point distribution (i.e., where the objects in the region are points). Because the max-min gap algorithm iteratively moves each object 108 to another location farther away from any nearest neighbor, it typically cannot achieve a perfect hexagonal point matrix. The algorithm produces a random distribution with a relatively high average hexagonal percentage, typically exceeding 90%.

[0107] The hard sphere distribution algorithm is a molecular dynamics simulation performed at finite temperatures. Specifically, it is the LAMMPS molecular dynamics simulator (https: / / www.lammps.org / , last accessed June 26, 2021). The result is that object 108 is randomly but specifically placed in region 110, unlike a hexagonal lattice. However, similarly, the hexagonal percentage is higher compared to that produced by the Poisson disk algorithm.

[0108] In any case, the position of the object 108 in region 110 thus becomes the predetermined position of each surface feature 52 subsequently formed into the substrate 12, or the predetermined position of each surface feature 52 derived from the position of the object 108 in region 110.

[0109] In one embodiment, at step 114, method 100 further includes: placing an etching mask 116 on the main surface 18 of the substrate 12. A subsequent step 102 for forming the surface feature 52 includes contacting the substrate 12 with an etchant 118 while the etching mask 116 is placed on the main surface 18 of the substrate 12.

[0110] In one embodiment, the etching mask 116 is formed on the substrate 12 as a superimposed positive or negative image of the region 110 on which the object 108 is placed using a spacing distribution algorithm. In other words, in one embodiment, the etching mask 116 is formed to match the placement of the object 108 on the main surface 18 of the substrate 12. In this case, the etching mask 116 prevents subsequent etching from forming the position of the surface feature 52 according to a predetermined location. In this case, the surface feature 52 produced by the etching step 102 protrudes from the surrounding portion 54. In other embodiments (such as...) Figure 4 In the example shown, the etching mask 116 is formed as a negative on which the object 108 is placed on the region 110, thereby preventing etching around the location where the portion 54 is to be present and allowing etching only at the location where the surface feature 52 is to be present (i.e., the location where the object is placed in the region).

[0111] In one embodiment, the etchant 118 comprises one or more of hydrofluoric acid and nitric acid. In another embodiment, the etchant 118 comprises both hydrofluoric acid and nitric acid. The etchant 118 can be sprayed onto the substrate 12 while the etching mask 116 is positioned on the substrate 12. The substrate 12 having the etching mask 116 can be immersed in a container 120 containing the etchant 118. In another embodiment, the duration of contact between the etchant 118 and the substrate 12 is 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, or 60 seconds, or within any range defined by any two of these values ​​(e.g., 10 seconds to 60 seconds, etc.). After this time period, the substrate 12 is rinsed in deionized water and dried. The longer the contact time between the etchant 118 and the substrate 12, the deeper the etchant 118 etches into the substrate 12, and therefore the greater the distance 42 between one or more higher surfaces 26 of the substrate 12 located at a higher average elevation 28 and one or more lower surfaces 32 of the substrate 12 located at a lower average elevation 34.

[0112] As mentioned, at step 104, method 100 includes depositing a high refractive index material 36 onto the surface feature 52 or the surrounding portion 54. In an embodiment, the high refractive index material 36 is deposited after the surface feature 52 is formed during step 102, while the etch mask 116 is still disposed on the substrate 12. Holding the etch mask 116 on the substrate 12 while depositing the high refractive index material 36 helps ensure that the high refractive index material 36 is deposited only where needed, such as only on one or more lower surfaces 32 of the substrate 12 located at a lower average elevation 34, whether these lower surfaces 32 are provided by the surface feature 52 or by the surrounding portion 54, rather than deposited onto one or more higher surfaces 26 located at a higher average elevation 28. The high refractive index material 36 can be deposited using various deposition methods such as vacuum deposition, chemical vapor deposition (e.g., plasma-enhanced chemical vapor deposition, low-pressure chemical vapor deposition, atmospheric pressure chemical vapor deposition, plasma-enhanced atmospheric pressure chemical vapor deposition), physical vapor deposition (e.g., reactive sputtering or non-reactive sputtering, or laser ablation), thermal evaporation or electron beam evaporation, and / or atomic layer deposition. In this embodiment, reactive sputtering is used to deposit the high refractive index material 36.

[0113] In one embodiment, at step 122, method 100 further includes removing the etch mask 116 after the high refractive index material 36 has been deposited at step 104. Depending on the composition of the etch mask 116, an organic solvent, such as acetone or isopropanol, may be used to remove the etch mask 116 from the substrate 12.

[0114] In a variation, prior to step 114, a film of a low-refractive-index material is deposited on the main surface 18 of the substrate 12. An etching mask 116 is then positioned on the substrate 12 above the low-refractive-index material. Then, at step 102, surface features 52 are formed by contacting the low-refractive-index material with an etchant 118 while the etching mask 116 is positioned on the low-refractive-index material. The remainder of method 100 is then performed as explained above.

[0115] Example

[0116] Comparative Example 1A—For Example 1, the implementation of the textured region of this disclosure was modeled as a diffraction grating using the commercial software package Gsolver (Developed by Grating Solver, Saratoga Springs, Utah, USA). The substrate was modeled as having a surrounding portion providing a surface at a higher average elevation, and then linear channels (as surface features) were disposed within the surrounding portion, providing a surface at a lower average elevation below the higher average elevation. The linear channels had a center-to-center spacing (grating period) of 20 μm. The model assumed that the ambient light had a single wavelength of 550 nm. The substrate was assumed to be glass with a refractive index of 1.518. A high refractive index material with a higher refractive index of 1.892, specifically SiO2, was used. x N y A 50% fill fraction is obtained by adding material to the surface of the linear channel located at the lower average elevation. Therefore, the high-refractive-index material provides the entire surface located at the intermediate average elevation, which lies between the higher and lower average elevations of the substrate. The air trench depth (the distance between the higher average elevation of the substrate and the intermediate average elevation of the high-refractive-index material deposited in the linear channel) is set to 220 nm. This trench depth (the distance between the higher and lower average elevations of the substrate) is then varied from approximately 220 nm to over 700 nm, and the height of the high-refractive-index material deposited in the channel is adjusted accordingly to maintain an air trench depth of 220 nm. The model then calculates the diffraction efficiency of light transmitted through the modeled textured region for diffraction orders 0 through 5 based on the variation in trench depth (and therefore also based on the height of the high-refractive-index material added to maintain the 220 nm air trench depth). Figure 6A ) and the diffraction efficiency of light reflected from self-modeled textured regions ( Figure 6B Both. Figure 6A and Figure 6B The modeling results of transmitted light and reflected light were reproduced at the respective locations.

[0117] Figure 6A Modeling results from the local reconstruction indicate that, in order to maximize the transmittance across the substrate leaving the textured region, the trench depth of the substrate should be 520 nm (0.52 μm). Therefore, the SiO2 added to the linear channels... x N y The height of the high-refractive-index material should be 300 nm to maintain an air trench depth of 220 nm. Unfortunately, as... Figure 6B The modeling results show that a trench depth of 520 nm in the substrate cannot completely reduce specular reflectivity (the 0th order is specular reflectivity).

[0118] Example 1B—Example 1B is a modeling example similar to Comparative Example 1A. However, unlike Comparative Example 1A, Example 1B does not fix the air trench depth and change the trench depth of the substrate. Instead, Example 1B modifies the air trench depth of the substrate with the SiO2 content. x N y The ratio of the height of the high-refractive-index material to the depth of the air trench is fixed at 3 / 1.6 / 1.4. The model determines the transmitted light ( Figure 7A ) and reflected light ( Figure 7B The diffraction efficiency varies with the trench depth depending on the substrate. The model parameters of Example 1B are otherwise identical to those of Comparative Example 1A, including SiO₂. x N y 50% filler fraction of high refractive index material.

[0119] Figure 7A The graph shows that regardless of the trench depth of the substrate, the 0th order (specular, not diffracted) transmittance across the substrate exiting the textured region remains high. Diffracted transmittance (1st order and higher) is extremely close to zero. This is because the ratio 3 / 1.6 / 1.4 mentioned above is close to the ideal ratio for a transparent diffuser. Figure 7B The graph shows that the specular reflectance (order 0) and diffuse reflectance (order 1 and higher) change significantly with the trench depth of the substrate. The specular reflectance peaks at trench depths of approximately 0.10 μm and 0.50 μm, making these trench depths less than preferred. However, the specular reflectance is minimized when the trench depth is between 0.22 μm and 0.37 μm. The diffracted reflectance of order 1 is further minimized at approximately 0.30 μm. Using the ratios mentioned above, when the trench depth of the substrate is between 0.22 μm and 0.37 μm, the SiO₂... x N y The high-refractive-index material has a height of 0.12 μm to 0.20 μm and an air trench depth of 0.10 μm to 0.20 μm. An exemplary target using this model is a trench depth of 0.32 μm in a substrate and 0.17 μm of SiO₂ disposed within surface features. x N y The model demonstrates the height of the high-refractive-index material and the depth of the air grooves at 0.15 μm. This model further illustrates that, with proper design, the textured regions revealed in this paper can suppress specular reflectivity by 5 to 10 times or more compared to untextured flat glass.

[0120] Now for reference Figure 7C and Figure 7D The model then determines based on SiO x N yThe transmission diffraction efficiency varies with different filling fractions of high-refractive-index materials (100% minus the filling fraction of low-refractive-index substrates). Figure 7C ) and the diffraction efficiency of reflection ( Figure 7D Both. The model assumes that the trench depth of the substrate is 0.32 μm, and that the SiO₂ is placed within the surface features. x N y The height of the high-refractive-index material is 0.17 μm and the depth of the air trench is 0.15 μm. For this model, a center-to-center distance of 20 μm and a wavelength of 550 nm are still assumed. Figure 7C The charts show that, according to the model, for all considered fill fractions, specular transmittance is high and transmitted scattering is low. This is because of the trench depth of the substrate and the SiO₂ deposited within the surface features. x N y The height of the high-refractive-index material and the depth of the air grooves have been optimized according to the transparent diffuser standard. Figure 7D The charts show that, according to the model, a fill fraction range of 52% to 62% for the substrate (low refractive index) minimizes specular reflection (order 0). This corresponds to 38% to 48% SiO₂. x N y The fill fraction range of high refractive index materials. In some applications, the optimized design may not only aim to suppress specular reflection (order 0), but may seek to minimize the intensity of specular reflectivity while also minimizing the intensity of one or more higher reflection diffraction orders (order 1, order 2, etc.). In applications where it is necessary to minimize the intensity of all reflection diffraction orders, the fill fraction of low refractive index substrate or low refractive index material can be as high as 75% or from about 55% to about 78%. This corresponds to 25% or from about 22% to about 45% of high refractive index material (e.g., SiO2). x N y The fill fraction.

[0121] Now for reference Figure 7E and Figure 7F The model determines the reflectivity ( Figure 7E ) and transmittance ( Figure 7F The optimal modeling parameters are obtained based on the varying incident light angle: SiO x N y A 45% filler content of high refractive index material, a trench depth of 0.32 μm in the substrate, and 0.17 μm of SiO₂. x N y The height of the high-refractive-index material and the depth of the air grooves are 0.15 μm. For example... Figure 7E As the diagram shows, this textured region is modeled to produce a specular reflectivity of less than 1% (first surface) for all light incident angles from 0 degrees to approximately 40 degrees. For example... Figure 7FAs the chart shows, this textured region is modeled to transmit more than 90% of incident light at all light incidence angles from 0 degrees to approximately 40 degrees.

[0122] Examples 2A to 2G—For Examples 2A to 2G, the position of each surface feature to be placed on the main surface 18 of the substrate is determined using the Hard Ball Spacing Distribution Algorithm (LAMMPS). The Hard Ball Spacing Distribution Algorithm aims to fill a specified area such that the placed object (a circular object) occupies 50% of the area. This translates to a high refractive index material deposited on the substrate having a target fill fraction of 50%. The circular object has a diameter of 50 μm and a minimum center-to-center spacing of 60 μm. More specifically, using software, a "molecular" gas representing the object (and thus the desired surface feature) is initially placed on a two-dimensional hexagonal lattice to fix the fill fraction at 50%. The gas is then heated and randomized in two dimensions. The molecules are given a repulsive hard ball potential to maintain the minimum center-to-center spacing of 60 μm. Figure 2 The resulting objects are placed within the area as illustrated in the chart. The resulting objects have an average hexagonal percentage of 0.49, which indicates a large deviation from the hexagonal lattice and therefore a highly randomized but specific placement. Figure 8 The reproduced chart is a histogram, showing how the fill fraction of all objects placed within the area varies depending on the actual center-to-center distance from the nearest neighbor object.

[0123] Etching masks were then formed on seven samples of glass substrates, with object placement superimposed according to a hard sphere spacing distribution algorithm. The etching mask for each sample was configured to allow etching into the substrate at the location where the hard sphere spacing distribution algorithm positions the object within the area, but to prevent etching into the substrate outside the object's location. The substrates of all seven samples with etching masks were then contacted with an etchant. The contact with the etchant lasted for a different duration for each sample, allowing the generation of surface features providing different trench depths. The etchant formed surface features disposed within a surrounding portion, where the surface features were positioned within the entire textured area where the algorithm placed the object. Two samples were then reserved as Examples 2F and 2G as comparative examples.

[0124] After etching, the etching mask is held on the substrate of the remaining samples of Examples 2A-2E. A high refractive index material, specifically AlN, having a higher refractive index (~2.1) compared to the substrate (~1.51), is deposited onto the surface of each of the surface features. The deposition times varied for some samples, resulting in variations in the height of the deposited high refractive index material. The etching mask is then removed from the substrate of each sample. Due to fabrication process steps and minor masking during deposition, the fill fraction of the high refractive index material AlN ranges from 40% to 49%.

[0125] Various optical measurements were then performed on all samples representing Examples 2A to 2G. Specifically, pixel power deviation (“PPD”), transmittance (“Trans.”), transmitted haze (“haze”), image sharpness (“DOI”), and specular reflectance (“Spec.Ref.”) were measured. The results for each sample, along with the height of the AlN high-refractive-index material deposited within each surface feature and the air trench depth, are illustrated in Table 1 below. The figures for “air trench depth” in Examples 2F and 2G refer to the elevation difference between the substrate located at the surface feature and the substrate located at the surrounding portion, because Examples 2F and 2G are comparative examples and did not have AlN high-refractive-index material deposited into the surface features. Figure 2 The optical profilometer scan of the reproduced surface is from Example 2C, which describes the deposition of AlN high-refractive-index material within the surface features.

[0126]

[0127]

[0128] Analysis of the data presented in Table 1 shows that, compared to Examples 2F and 2G, the incorporation of high-refractive-index materials into the surface features of Examples 2A to 2E significantly reduces pixel power deviation without substantially adversely affecting other measured optical properties. Examples 2B and 2C specifically illustrate a beneficial combination of measured optical properties—specifically, a pixel power deviation of less than 1.5, transmittance greater than 92%, transmittance haze less than 2%, image sharpness less than 50%, and specular reflectance less than 0.85%. These combinations of values ​​are difficult or impossible to achieve using other methods, especially when the surface feature has a maximum dimension of approximately 50 μm, which is easier to manufacture than when the surface feature has a smaller maximum dimension.

[0129] Examples 3A to 3D—For Examples 3A to 3D, the position of each surface feature to be placed on the main surface of the substrate is determined using an algorithm based on the distance distribution between samples from a Poisson disk. The algorithm aims to fill a specified area such that the placed object (a circular object) occupies 36% of the area. This translates to a high-refractive-index material deposited within the surface feature having a target fill fraction of 36%. The circular object has a diameter of 50 μm and a minimum center-to-center spacing of 60 μm. The circles placed within the area by the algorithm have a hexagonal percentage H of 0.41, which is low and considered highly randomized. Figure 9 The chart reproduced here is a histogram, showing how the fill fraction of all objects placed in the area varies depending on the actual center-to-center distance from the nearest neighbor object.

[0130] Etching masks were then formed on four samples of the glass substrate, with the placement of the object superimposed according to a hard sphere spacing distribution algorithm. The etching mask for each sample was configured to allow etching into the substrate at the location where the hard sphere spacing distribution algorithm positions the object within the area, but to prevent etching into the substrate outside the object's location. The substrates of all four samples with etching masks were then contacted with an etchant. The etchant formed a surface feature disposed within the surrounding portion, wherein the surface feature was positioned within the entire textured area where the algorithm placed the object within the area. Two samples were then reserved as Examples 3C and 3D for comparison.

[0131] After etching, the etching mask is held on the substrate of the remaining samples of Examples 3A to 3B. A high refractive index material, specifically AlN, having a higher refractive index (~2.1) compared to the substrate (~1.51), is deposited in each of the surface features by reactive sputtering. The etching mask is then removed from the substrate of each sample. Due to the fabrication process steps and slight masking during deposition, the fill fraction of the AlN high refractive index material is in the range of 30% to 35%.

[0132] Various optical measurements were then performed on all samples representing Examples 3A to 3D. Specifically, pixel power deviation (“PPD”), transmittance (“Trans.”), transmitted haze (“haze”), image sharpness (“DOI”), and specular reflectance (“Spec.Ref.”) were measured. The results for each sample, along with the height of the AlN high-refractive-index material deposited within each surface feature and the air trench depth, are illustrated in Table 2 below. The “air trench depth” figures for Examples 3C and 3D refer to the depth of the surface feature relative to the surrounding portion (since no AlN was added).

[0133]

[0134] Analysis of the data presented in Table 2 shows that, compared to Examples 3C and 3D, the incorporation of high-refractive-index materials into the surface features of Examples 3A to 3B significantly reduces pixel power deviation without substantially adversely affecting other measured optical properties. The image sharpness values ​​of less than 85% in Examples 3A and 3B indicate that specular reflection is suppressed.

Claims

1. A substrate for a display article, the substrate comprising: Main surface; and A textured region located on at least a portion of the main surface, the textured region comprising: One or more higher surfaces located at a higher average elevation, the higher average elevation being parallel to a base plane, the base plane being positioned below the textured region; One or more lower surfaces located at a lower average elevation, said lower average elevation being parallel to the base plane, and said lower average elevation being less than said higher average elevation; and A high-refractive-index material is disposed on each of one or more lower surfaces, the high-refractive-index material forming one or more intermediate surfaces at an intermediate average elevation parallel to a base plane, the intermediate average elevation being greater than the lower average elevation but less than the higher average elevation, the high-refractive-index material comprising a refractive index greater than the refractive index of the substrate or low-refractive-index material providing the one or more higher surfaces. in, The intermediate average elevation of the high refractive index material is 100 nm to 200 nm greater than the lower average elevation of the one or more lower surfaces.

2. The substrate as claimed in claim 1, wherein: The refractive index of the substrate or low-refractive-index material is in the range of 1.4 to 1.6; and The refractive index of a high-refractive-index material is higher than that of the substrate or the low-refractive-index material.

3. The substrate as described in claim 1 or claim 2, wherein, The intermediate average elevation of the high refractive index material is 100 nm to 190 nm smaller than the higher average elevation of the one or more higher surfaces.

4. The substrate as claimed in claim 1 or claim 2, wherein, The intermediate average elevation of the high refractive index material is 130 nm to 180 nm smaller than the higher average elevation of the one or more higher surfaces.

5. The substrate as claimed in claim 1 or claim 2, wherein, The high-refractive-index material occupies 22% to 49% of a plane, which is (i) parallel to the base plane and (ii) extends through the high-refractive-index material, and the region is defined by the textured region.

6. The substrate as claimed in claim 1 or claim 2, wherein, The substrate includes a glass substrate or a glass-ceramic substrate.

7. The substrate as claimed in claim 1 or claim 2, wherein, The textured region exhibits a pixel power deviation ranging from 1.2% to 2.1%.

8. The substrate as claimed in claim 1 or claim 2, wherein, The textured region exhibits a pixel power deviation of less than 1.5%.

9. The substrate as claimed in claim 1 or claim 2, wherein, The textured areas exhibit a specular reflectance of 0.5% to 1.75%.

10. The substrate as claimed in claim 1 or claim 2, wherein, The textured area exhibits a specular reflectance of less than 0.85%.

11. The substrate as claimed in claim 1 or claim 2, wherein, The textured areas exhibit 25% to 85% image clarity.

12. The substrate as claimed in claim 1 or claim 2, wherein, The textured areas exhibit less than 50% image clarity.

13. The substrate as claimed in claim 1 or claim 2, wherein, The textured area exhibits a transmission haze of less than 2.5%.

14. The substrate as claimed in claim 1 or claim 2, wherein, The textured region exhibits a transmittance of more than 92%.

15. The substrate as claimed in claim 1 or claim 2, wherein, The high refractive index material includes AlNx, SiOxNy, or SiNx.

16. The substrate as claimed in claim 1 or claim 2, wherein, The textured region includes air grooves located above the high-refractive-index material, having an air groove depth between the higher average elevation and the intermediate average elevation.

17. The substrate of claim 16, wherein, The intermediate average elevation of the high refractive index material is 120 nm to 180 nm greater than the lower average elevation of the one or more lower surfaces.

18. The substrate as claimed in claim 16, wherein, The lower average elevation of the one or more lower surfaces is 220 nm to 370 nm smaller than the higher average elevation of the one or more higher surfaces.

19. A method for forming a textured region on a substrate for a display article, the method comprising: A textured region is formed by protruding from or disposed within a surrounding portion of a substrate at a predetermined position for each surface feature, wherein (i) one or more higher surfaces of the textured region are located at a higher average elevation parallel to a base plane disposed below the textured region; (ii) one or more lower surfaces of the textured region are located at a lower average elevation parallel to the base plane and less than the higher average elevation; (iii) the surface feature provides either the one or more higher surfaces or the one or more lower surfaces; and (iv) the surrounding portion provides the other of the one or more higher surfaces or the one or more lower surfaces, wherein the surface feature does not provide either. A high refractive index material is deposited on either the surface feature or the surrounding portion that provides one or more lower surfaces located at the lower average elevation, wherein the high refractive index material (i) exhibits a refractive index greater than that of the substrate, and (ii) forms one or more intermediate surfaces located at an intermediate average elevation parallel to the base plane, the intermediate average elevation being between the higher and lower average elevations. in, The intermediate average elevation of the high refractive index material is 100 nm to 200 nm greater than the lower average elevation of the one or more lower surfaces.

20. A substrate for a display article, the substrate comprising: Main surface; and A textured region located on at least a portion of the main surface, the textured region comprising: One or more higher surfaces located at a higher average elevation, said higher average elevation being parallel to a base plane, said base plane being positioned below the textured region and extending through the substrate; One or more lower surfaces located at a lower average elevation, the lower average elevation being parallel to the base plane, and the lower average elevation being less than the higher average elevation; and A high-refractive-index material is disposed on each of one or more lower surfaces located at a lower average elevation, the high-refractive-index material forming one or more intermediate surfaces located at an intermediate average elevation parallel to a base plane, the intermediate average elevation being greater than the lower average elevation but less than the higher average elevation, the high-refractive-index material comprising a refractive index greater than the refractive index of the substrate or low-refractive-index material providing the one or more higher surfaces. The textured region exhibits a pixel power deviation in the range of 1.2-2.1%, and a specular reflectance in the range of 0.5-1.75%, wherein the refractive index of the substrate or low-refractive-index material is in the range of 1.4 to 1.6; and Among them, the refractive index of high refractive index materials is in the range of 1.6 to 2.

3.

21. A substrate for a display article, the substrate comprising: Main surface; and A textured region located on at least a portion of the main surface, the textured region comprising: One or more higher surfaces located at a higher average elevation, said higher average elevation being parallel to a base plane, said base plane being positioned below the textured region and extending through the substrate; One or more lower surfaces located at a lower average elevation, the lower average elevation being parallel to the base plane, and the lower average elevation being less than the higher average elevation; Surface features that protrude from or are disposed within a surrounding portion located on a main surface, wherein (i) the surface features provide either one or more higher surfaces or one or more lower surfaces, and (ii) the surrounding portion provides another of one or more higher surfaces or one or more lower surfaces, whichever is not provided by the surface features; and A high-refractive-index material disposed on one or more lower surfaces at a lower average elevation, the high-refractive-index material comprising (i) a refractive index greater than that of a substrate or a low-refractive-index material providing the one or more higher surfaces, and (ii) one or more intermediate surfaces at an intermediate average elevation parallel to the base plane, the intermediate average elevation being between the higher average elevation and the lower average elevation. Each surface feature has a perimeter parallel to the base plane; and The perimeter of each surface feature has a maximum dimension ranging from 5 μm to 200 μm.

22. The substrate of claim 20, wherein The intermediate average elevation of the high refractive index material is 100 nm to 190 nm smaller than the higher average elevation of the one or more higher surfaces, and The lower average elevation of the one or more lower surfaces is 220 nm to 370 nm smaller than the higher average elevation of the one or more higher surfaces.

23. The substrate of claim 21, wherein The intermediate average elevation of the high refractive index material is 100 nm to 190 nm smaller than the higher average elevation of the one or more higher surfaces, and The lower average elevation of the one or more lower surfaces is 220 nm to 370 nm smaller than the higher average elevation of the one or more higher surfaces.

24. A substrate for a display article, the substrate comprising: Main surface; and A textured region located on at least a portion of the main surface, the textured region comprising: One or more higher surfaces located at a higher average elevation, said higher average elevation being parallel to a base plane, said base plane being positioned below the textured region and extending through the substrate; One or more lower surfaces located at a lower average elevation, the lower average elevation being parallel to the base plane, and the lower average elevation being less than the higher average elevation; and A high-refractive-index material is disposed on each of one or more lower surfaces located at a lower average elevation, the high-refractive-index material forming one or more intermediate surfaces located at an intermediate average elevation parallel to a base plane, the intermediate average elevation being greater than the lower average elevation but less than the higher average elevation, the high-refractive-index material comprising a refractive index greater than the refractive index of the substrate or low-refractive-index material providing the one or more higher surfaces. The textured region exhibits a pixel power deviation of less than 1.5%. The textured region exhibits a specular reflectance of less than 0.85%. The refractive index of the substrate or low-refractive-index material is in the range of 1.4 to 1.6; and Among them, the refractive index of high refractive index materials is in the range of 1.6 to 2.

3.

25. The substrate of claim 24, wherein The intermediate average elevation of the high refractive index material is 100 nm to 190 nm smaller than the higher average elevation of the one or more higher surfaces. The lower average elevation of the one or more lower surfaces is 220 nm to 370 nm smaller than the higher average elevation of the one or more higher surfaces; and The intermediate average elevation of the high refractive index material is 100 nm to 200 nm greater than the lower average elevation of the one or more lower surfaces.

26. The substrate as claimed in claim 24 or claim 25, wherein, The high-refractive-index material occupies 22% to 49% of a plane, which is (i) parallel to the base plane and (ii) extends through the high-refractive-index material, and the region is defined by the textured region.

27. The substrate as claimed in claim 24 or claim 25, wherein, The substrate includes a glass substrate or a glass-ceramic substrate.

28. The substrate as claimed in claim 24 or claim 25, wherein, The textured areas exhibit 25% to 85% image clarity.

29. The substrate as claimed in claim 24 or claim 25, wherein, The textured areas exhibit less than 50% image clarity.

30. The substrate as claimed in claim 24 or claim 25, wherein, The textured area exhibits a transmission haze of less than 2.5%.

31. The substrate as claimed in claim 24 or claim 25, wherein, The textured region exhibits a transmittance of more than 92%.

32. The substrate as claimed in claim 24 or claim 25, wherein, The method wherein the high refractive index material comprises AlNx, SiOxNy, or SiNx.

33. A substrate for a display article, the substrate comprising: Main surface; and A textured region located on at least a portion of the main surface, the textured region comprising: One or more higher surfaces located at a higher average elevation, said higher average elevation being parallel to a base plane, said base plane being positioned below the textured region and extending through the substrate; One or more lower surfaces located at a lower average elevation, the lower average elevation being parallel to the base plane, and the lower average elevation being less than the higher average elevation; A high-refractive-index material is disposed on each of one or more lower surfaces located at a lower average elevation, the high-refractive-index material forming one or more intermediate surfaces located at an intermediate average elevation parallel to a base plane, the intermediate average elevation being greater than the lower average elevation but less than the higher average elevation, the high-refractive-index material comprising a refractive index greater than the refractive index of the substrate or low-refractive-index material providing the one or more higher surfaces. The textured region exhibits a pixel power deviation of less than 1.5%. The textured region exhibits a specular reflectance of less than 0.85%, and The textured areas exhibit less than 50% image clarity.

Images