Display articles with diffractive, antiglare surfaces and methods of making the same
A display article is described herein that includes: a substrate comprising a thickness and a primary surface; and the primary surface having defined thereon a diffractive surface region. The diffractive surface region comprises a plurality of structural features that comprises a plurality of different heights in a multimodal distribution. Further, the substrate exhibits a sparkle of less than 4%, as measured by pixel power deviation (PPD 140 ) at an incident angle of 0° from normal, a distinctness of image (DOI) of less than 80% at an incident angle of 20° from normal, and a transmittance haze of less than 20% from an incident angle of 0° from normal.
1. A display article, comprising:
a substrate comprising a thickness and a primary surface; and
the primary surface having defined thereon a diffractive surface region,
wherein the diffractive surface region comprises a plurality of structural features that comprises a plurality of different heights in a multimodal distribution,
wherein the multimodal distribution comprises a plurality of modes, with each mode being distinguished by a decrease in area fraction of at least 20 % from a peak surface height value of the mode, and
wherein the substrate exhibits a sparkle of less than 4%, as measured by pixel power deviation (PPD 140 ) at an incident angle of 0° from normal, a distinctness of image (DOI) of lessthan 80% at an incident angle of 20° from normal, and a transmittance haze of less than 20% from an incident angle of 0° from normal.
2. The display article according to claim 1 , wherein the plurality of structural features further comprises a first portion of structural features having a first average height and a second portion of structural features having a second average height.
3. The display article according to claim 2 , wherein the first average height and the second average height have a difference of from 50 nm to 250 nm.
4. The display article according to claim 2 , wherein the first average height and the second average height have a difference of from 120 nm to 200 nm.
5. The display article according to claim 2 , wherein the diffractive surface region further comprises a first planar region corresponding to the first average height and a second planar region corresponding to the second average height, and
further wherein each of the first planar region and the second planar region comprises a root-mean-square (RMS) height variation of less than 50 nm.
6. The display article according to claim 5 , wherein the first and second planar regions have a total surface area that is at least 50% of a total surface area of the diffractive surface region.
7. The display article according to claim 1 , wherein the substrate comprises a glass substrate or a glass-ceramic substrate.
8. The display article according to claim 1 , wherein the substrate further exhibits a sparkle of less than 2%, as measured by PPD 140 at an incident angle of 0° from normal.
9. The display article according to claim 1 , wherein the substrate further exhibits a transmittance haze of less than 5% from an incident angle of 0° from normal.
10. The display article according to claim 1 , wherein the substrate further exhibits a first-surface absolute specular reflectance (% R) of less than 1% at an incident angle of 20° from normal.
11. The display article according to claim 1 , further comprising:
an antireflective coating disposed on the primary surface of the substrate,
wherein the antireflective coating comprises a plurality of alternating high index and low index layers,
wherein each of the low index layers comprises a refractive index of less than about 1.8, and wherein each of the high index layers comprises a refractive index that is greater than 1.8, and
further wherein the article exhibits a first-surface absolute specular reflectance (% R) of less than 0.3% at an incident angle of 20° from normal.
12. A display article, comprising:
a substrate comprising a thickness and a primary surface; and
the primary surface having defined thereon a diffractive surface region,
wherein the diffractive surface region comprises a plurality of structural features comprising a pitch of less than 125 μm and a fill fraction from 30% to 70%, each structural feature comprising a diameter of less than 100 μm, and
further wherein the substrate exhibits a sparkle of less than 4%, as measured by pixel power deviation (PPD 140 ) at an incident angle of 0° from normal, a distinctness of image (DOI) of less than 80% at an incident angle of 20° from normal, and a transmittance haze of less than 20% from an incident angle of 0° from normal, wherein the diffractive surface region further comprises a first planar region disposed at a first average height and a second planar region disposed at a second average height, wherein each of the first planar region and the second planar region comprises a root-mean-square (RMS) height variation of lesss than 50 nm.
13. The display article according to claim 12 , wherein a first portion of the plurality of structural features comprises pillars having the first average height, wherein the first average height differs from the second average height by a height difference that is from 50 nm to 250 nm.
14. The display article according to claim 13 ,
wherein the plurality of structural features further comprises a plurality of heights in a multimodal distribution, and
further wherein the first portion of structural features has a first fill fraction from 30 to 70%.
15. The display article according to claim 12 , wherein a first portion of the plurality of structural features comprises holes having the second average height, wherein the first average height differs from the second average height by a height difference that is from 50 nm to 250 nm.
16. The display article according to claim 15 ,
wherein the plurality of structural features further comprises a plurality of depths in a multimodal distribution,
further wherein the first portion of structural features has a first fill fraction from 30 to 70%.
17. The display article according to claim 12 , further comprising:
an antireflective coating disposed on the primary surface of the substrate,
wherein the antireflective coating comprises a plurality of alternating high index and low index layers,
wherein each of the low index layers comprises a refractive index of less than about 1.8, and wherein each of the high index layers comprises a refractive index that is greater than 1.8, and
further wherein the article exhibits a first-surface absolute specular reflectance (% R) of less than 0.3% at an incident angle of 20° from normal.
18. A display article, comprising:
a substrate comprising a thickness and a primary surface; and
the primary surface having defined thereon a diffractive surface region,
wherein the diffractive surface region comprises a plurality of structural features comprising a pitch of less than 125 μm, a fill fraction from 30% to 70%, and
further wherein each structural feature comprises a height or depth of from 50 nm to 250 nm, wherein the diffractive surface region further comprises a first planar region disposed at a first average height and a second planar region disposed at a second average height, wherein each of the first planar region and the second planar region comprises a root-mean-square (RMS) height variatin of less than 50 nm.
19. The display article according to claim 18 , wherein the plurality of structural features further comprises a non-random spatial distribution.
20. The display article according to claim 18 , further comprising:
an antireflective coating disposed on the primary surface of the substrate,
wherein the antireflective coating comprises a plurality of alternating high index and low index layers,
wherein each of the low index layers comprises a refractive index of less than about 1.8, and wherein each of the high index layers comprises a refractive index that is greater than 1.8, and
further wherein the article exhibits a first-surface absolute specular reflectance (% R) of less than 0.3% at an incident angle of 20° from normal.
21. A method of making a display article, comprising:
masking a substrate comprising a thickness and a primary surface with a mask;
forming a diffractive surface region within the primary surface of the substrate with the mask; and
removing the mask from the substrate,
wherein the diffractive surface region comprises a plurality of structural features that comprises a plurality of different heights in a multimodal distribution, wherein the multimodal distribution comprises a plurality of modes, with each mode being distinguished by a decrease in area fraction of at least 20% from a peak surface height value of the mode, wherein the plurality of structural features further comprises a first portion of structural features at a first average height and a second portion of structural features at a second average height, and
wherein the substrate exhibits a sparkle of less than 4%, as measured by pixel power deviation (PPD 140 ) at an incident angle of 0° from normal, a distinctness of image (DOI) of less than 80% at an incident angle of 20° from normal, and a transmittance haze of less than 20% from an incident angle of 0° from normal.