Glass having antiglare surface with low display sparkle

Patent metadata

Field	Value
Publication number	US-9701579-B2
Application number	US-201213405787-A
Country	US
Kind code	B2
Filing date	Feb 27, 2012
Priority date	Feb 28, 2011
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A glass article having a low level of grainy appearance that can appear to have a shift in the pattern of the grains with changing viewing angle of a display, or “sparkle.” The glass article—which, in some embodiments, is a transparent glass sheet—has small-angle-scattering properties and/or distinctness-of-reflected-image (DOI), leading to improved viewability in display applications, especially under high ambient lighting conditions. In some embodiments, the antiglare surface of the glass sheet is an etched surface, with no foreign coating present on the antiglare surface.

First claim

The invention claimed is:

1. A transparent glass sheet, the transparent glass sheet having at least one antiglare surface, wherein the antiglare surface has:
a first RMS surface roughness Rlong of up to about 300 nm measured in a range of lateral spatial periods from about 40 μm to about 640 μm;
a second RMS surface roughness Rshort measured at lateral spatial periods of less than about 20 μm, wherein the ratio (Rlong/Rshort) is less than about 3.9; and
a third RMS roughness Rtotal, measured without surface wavelength filtering, wherein the third RMS roughness Rtotal is in a range from about 60 nm to about 600 nm, and wherein the transparent glass sheet has a pixel power deviation of less than about 7.5% when disposed in front of a pixelated display having a plurality of pixels and an imaging plane such that the antiglare surface is distal from the pixelated display and separated from the imaging plane by a predetermined distance, and wherein the transparent glass sheet has a 20° distinctness of image of less than about 60.

2. The transparent glass sheet of claim 1 , wherein the transparent glass sheet has a 20° distinctness of image of less than about 85.

3. The transparent glass sheet of claim 1 , wherein Rshort is at least about 30 nm.

4. The transparent glass sheet of claim 1 , wherein the transparent glass sheet has a transmission haze of less than about 20%.

5. The transparent glass sheet of claim 1 , wherein the transparent glass sheet is strengthened.

6. The transparent glass sheet of claim 5 , wherein the transparent glass sheet is strengthened by ion exchange, and wherein the transparent glass sheet has at least one surface having a region under a compressive stress, the region extending from the surface to a depth of layer within the transparent glass sheet.

7. The transparent glass sheet of claim 6 , wherein the compressive stress is at least about 350 MPa and the depth of layer is at least 15 μm.

8. The transparent glass sheet of claim 1 , wherein the transparent glass sheet comprises one of a soda lime glass, an alkali aluminosilicate glass, and an alkali aluminoborosilicate glass.

9. The transparent glass sheet of claim 8 , wherein the glass comprises at least 2 mol % of Al 2 O 3 or ZrO 2 .

10. The transparent glass sheet of claim 1 , wherein the transparent glass sheet has a 20° distinctness of image of less than about 80.

11. The transparent glass sheet of claim 1 , wherein the pixelated display alone has a second pixel power deviation, and wherein pixel power deviation of the transparent glass sheet combined with the pixelated display is less than about 4% greater than the second pixel power deviation.

12. The transparent glass sheet of claim 1 , wherein the pixelated display alone has a second pixel power deviation, and wherein pixel power deviation of the transparent glass sheet combined with the pixelated display is less than about two times greater than the second pixel power deviation.

13. The transparent glass sheet of claim 12 , wherein the pixelated display has a sub-pixel window opening dimension of less than 200 μm.

14. The transparent glass sheet of claim 12 , wherein the predetermined distance between the imaging plane and the antiglare surface is in a range from about 1.0 mm to about 3.5 mm.

15. The transparent glass sheet of claim 1 , further comprising an antireflective layer disposed over the antiglare surface.

16. The transparent glass sheet of claim 1 , wherein the transparent glass sheet comprises a second surface opposite the antiglare surface, wherein the second surface has an RMS roughness of less than about 20 nm.

17. The transparent glass sheet of claim 1 , wherein the first RMS surface roughness Rlong is measured in a range of lateral spatial periods from about 80 μm to about 640 μm and the ratio Rtotal/Rlong is greater than or equal to about 2.20.

18. The transparent glass sheet of claim 1 , wherein the first RMS surface roughness Rlong is measured in a range of lateral spatial periods from about 80 μm to about 640 μm, the second RMS surface roughness Rshort is greater than about 30 nm, and the ratio Rtotal/Rlong is greater than or equal to about 1.80.

19. A display system, the display system comprising:
a pixelated display having a plurality of pixels and an imaging plane; and
a transparent glass sheet having an antiglare surface, wherein the transparent glass sheet is disposed in front of the pixelated display such that the antiglare surface is distal from the pixelated display and separated from the imaging plane by an optical distance, wherein the transparent glass sheet has a pixel power deviation of less than about 7.5%, wherein the transparent glass sheet has a 20° distinctness of image of less than about 60, and wherein the antiglare surface has a first RMS surface roughness Rlong of up to about 300 nm measured in a range of lateral spatial periods from about 40 μm to about 640 μm;
a second RMS surface roughness Rshort measured at lateral spatial periods of less than about 20 μm, wherein the ratio (Rlong/Rshort) is less than about 3.9; and
a third RMS roughness Rtotal, measured without surface wavelength filtering, wherein the third RMS roughness Rtotal is in a range from about 60 nm to about 600 nm.

20. The display system of claim 19 , wherein the transparent glass sheet has a 20° distinctness of image of less than about 40.

21. The display system of claim 19 , wherein the pixelated display alone has a second pixel power deviation, and wherein pixel power deviation of the transparent glass sheet combined with the pixelated display is less than about 4% greater than the second pixel power deviation.

22. The display system of claim 19 , wherein the pixelated display alone has a second pixel power deviation, and wherein pixel power deviation of the transparent glass sheet combined with the pixelated display is less than about two times greater than the second pixel power deviation.

23. The display system of claim 22 , wherein the display system has a minimum sub-pixel window opening dimension of less than 200 μm.

24. The display system of claim 22 , wherein the optical distance between the imaging plane and the antiglare surface is in a range from about 1.0 mm to about 3.5 mm.

25. The display system of claim 19 , wherein the transparent glass sheet is strengthened.

26. The display system of claim 25 , wherein the transparent glass sheet is strengthened by ion exchange, and wherein the transparent glass sheet has at least one surface having a region under a compressive stress, the region extending from the surface to a depth of layer within the transparent glass sheet.

27. The display system of claim 26 , wherein the compressive stress is at least about 350 MPa and the depth of layer is at least 15 μm.

28. The display system of claim 19 , wherein the transparent glass sheet comprises one of a soda lime glass, an alkali aluminosilicate glass, and an alkali aluminoborosilicate glass.

29. The display system of claim 28 , wherein the glass comprises at least 2 mol % of Al 2 O 3 or ZrO 2 .

30. The display system of claim 21 , wherein the transparent glass sheet has an Rshort of at least about 30 nm.

31. The display system of claim 30 , wherein the transparent glass sheet has a transmission haze of less than about 20%.

32. A method of mak

Assignees

• Gollier Jacques
• Hart Shandon Dee
• Nguyen Kelvin
• Stephens Ii Alan Thomas
• West James Andrew
• Zhang Lu
• Corning Inc

Inventors

• Gollier Jacques
• Hart Shandon Dee
• Nguyen Kelvin
• Stephens Ii Alan Thomas
• West James Andrew
• Zhang Lu

Classifications

• G02F1/133502

  Antiglare, refractive index matching layers · CPC title

• G02B5/0294

  adapted to provide an additional optical effect, e.g. anti-reflection or filter · CPC title

• G02B5/0215 Primary

  the surface having a regular structure · CPC title

• C03C21/002 Primary

  to perform ion-exchange between alkali ions (C03C21/005 takes precedence) · CPC title

• C03C2204/08

  Glass having a rough surface · CPC title