Display device including light extraction device

Abstract

A display apparatus includes a light extraction device. The light extraction device includes: a first sheet including a first main surface; and a second sheet material which is arranged on the first sheet material. At least one of the first sheet or the second sheet includes a plurality of pyramids, wherein a plurality of spaces between the pyramids of the pyramid structure are filled with another sheet. The second sheet includes a second major surface extending along a second plane parallel to the first major surface. In aspects, at least the first sheet or the second sheet has a refractive index of about 1.6 or greater, or about 1.65 to about 1.9. In aspects, a base angle of one of the plurality of pyramid structures ranges from about 60 degrees to about 80 degrees.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority under 35 U.S.C. §119 to U.S. Provisional Application Serial No. 63 / 391,887, filed on July 25, 2022, the contents of which are the basis of this application and are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates generally to light extraction devices and display apparatuses including the same, and more particularly to light extraction devices and display apparatuses including a plurality of pyramid structures. Background Art

[0004] Glass sheets can be used in display applications, such as liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light emitting diode displays (OLEDs), and plasma display panels (PDPs). It is known to provide a backlight in display applications to illuminate the display. However, display applications using a backlight may have limited light extraction, which limits the brightness of the backlight reaching a viewer and may result in backlight heating due to light loss caused by absorption within the backlight. Therefore, a light extraction device is needed to increase the brightness of light extracted from the backlight, such as in display applications. Summary of the invention

[0005] A simplified summary of the present disclosure is presented below to provide a basic understanding of some aspects described in the detailed description. Various aspects of the present disclosure provide a light extraction device or a display device including a light extraction device, wherein the light extraction device includes a sheet having a high refractive index and a plurality of pyramid structures. Providing a high refractive index of about 1.6 or greater (e.g., about 1.65 or greater, about 1.7 or greater, or about 1.75 or greater) can increase the brightness of the light extracted from the light extraction device. Providing a high refractive index of about 1.9 or less (e.g., about 1.88 or less, about 1.85 or less, about 1.8 or less) can increase the brightness of the light extracted from the light extraction device, for example, by reducing the light loss from Fresnel reflection. As discussed with respect to the following examples, a specific range of high refractive indices (and / or the absolute difference between the refractive indices of each sheet) can provide an unexpected benefit, namely, improving the brightness of the light extracted from the light extraction device (e.g., light extraction device, display device), which can be further improved for specific pyramid structures (e.g., triangles, squares, hexagons).

[0006] For the first sheet, the plurality of pyramid structures include a base angle, the base angle being defined as the interior angle between the second patterned surface and the first major surface; for the second sheet, the plurality of pyramid structures include a base angle, the base angle being defined as the interior angle between the first patterned surface and a second plane extending along the second major surface of the second sheet. Pyramids having base angles approaching 90° (e.g., about 80° or greater) may be more expensive and / or more difficult to manufacture, and may use more material (e.g., about 50° to about 80°, about 60° to about 80°) than pyramids having smaller base angles. Providing a base angle of about 60° or greater (e.g., about 65° or greater, about 70° or greater, about 75° or greater) can increase the brightness of light extracted from the light extraction device, for example by reducing TIR. As discussed with respect to the examples below, a specific range of base angles (and / or the ratio of the height of the pyramid structure to the width of the pyramid structure) can provide an unexpected benefit of increasing the brightness of light extracted from a light extraction device (e.g., a light extraction device, a display device), which can be further refined for specific pyramid structures (e.g., triangles, squares, hexagons). Further, combining the high refractive index (and / or the absolute value of the difference between the refractive indices) in the range with the base angle (and / or the ratio of height to width) in the range can further unexpectedly increase the brightness of light extracted from the light extraction device. Setting the ratio of the radius of curvature to the pyramid height at about 0.20 or less (e.g., about 0.15 or less, about 0.10 or less) can maintain the brightness increase achieved by the above-mentioned high refractive index (and / or the absolute difference between the first refractive index and the second refractive index) within the range of base angles (and / or the ratio of height to width). Providing triangular pyramids, quadrangular pyramids and / or hexagonal pyramids may enable the plurality of pyramids to be close-packed, thereby increasing the density of the pyramids and thus improving the brightness of light extracted from the light extraction device.

[0007] Providing a second sheet disposed on the first sheet can enable multiple spaces between the multiple corner cone structures to be filled, which can reduce light scattering at the second patterned surface, which can result in reduced haze, improved image resolution and / or increased brightness of light extracted from the light extraction device. Setting the absolute value of the difference in refractive index to about 0.4 or less (e.g., about 0.35 or less, about 0.3 or less) can increase the brightness of the light extracted from the light extraction device. Setting the absolute value of the difference in refractive index to about 0.15 or greater (e.g., about 0.20 or less, about 0.25 or greater) can increase the brightness of the light extracted from the light extraction device. Providing a second major surface of the second sheet (which, for example, extends along a second plane) can efficiently extract light from the light extraction device to the substrate (if provided) and simplify the manufacture of the light extraction device.

[0008] In various aspects, the first sheet material may include a high refractive index. The high refractive index of the first sheet material may increase the brightness of light extracted from the light extraction device, for example, by reducing total internal reflection (TIR) ​​of light to be coupled into the light extraction device. Providing a second sheet material having a second refractive index less than the high refractive index may increase the brightness of light extracted from the light extraction device, for example, by reducing Fresnel reflections at the interface between the second patterned surface and the first patterned surface and / or by reducing total internal reflections at the second major surface (e.g., light to be coupled out of the light extraction device).

[0009] In various aspects, a display device may include a dichroic mirror and / or a polarizer. Providing a dichroic mirror can increase the illumination of a backlight device, for example, by reflecting light emitted from a phosphor material layer and incident on the dichroic mirror. Providing a polarizer can increase contrast and / or reduce glare, for example, by reducing ambient light entering a sub-pixel so that it is not transmitted to an observer. Alternatively, providing a low percentage (e.g., about 66% or less, about 50% or less, about 40% or less, about 33% or less, about 25% or less) of the pixel area occupied by the sub-pixel can allow the dichroic mirror and / or polarizer to be omitted without increasing glare, reducing contrast, or reducing illumination beyond a predetermined threshold of the corresponding value.

[0010] Aspect 1. A display device, comprising: a backlight device, the backlight device being configured to emit light through a light-emitting surface of the backlight device. The display device comprises a light extraction device, the light extraction device comprising a first sheet, the first sheet comprising a first main surface extending along a first plane. The first main surface is arranged on the light-emitting surface. The light extraction device comprises a second sheet arranged on the first sheet. The second sheet comprises a second main surface extending along a second plane parallel to the first plane. The first refractive index of the first sheet or the second refractive index of the second sheet is about 1.6 or greater. The absolute value of the difference between the first refractive index and the second refractive index is about 0.1 to about 0.4. The light extraction device comprises at least one of the following: the first sheet comprises a first plurality of pyramid structures, a first plurality of spaces between the first plurality of pyramid structures are filled by the second sheet; or the second sheet comprises a second plurality of pyramid structures, a second plurality of spaces between the second plurality of pyramid structures are filled by the first sheet.

[0011] Aspect 2. The display device according to aspect 1, wherein the first refractive index or the second refractive index is about 1.65 to about 1.9.

[0012] Aspect 3. A display device as described in any of Aspects 1-2, wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures includes a plurality of triangular pyramids, a plurality of quadrangular pyramids, a plurality of hexagonal pyramids, or a combination thereof arranged in a closely packed configuration.

[0013] Aspect 4. A display device as described in any of Aspects 1-3, wherein at least one of the following situations exists: a first base angle of a corner pyramid structure among the first plurality of corner pyramid structures is defined as an inner angle relative to the first plane, and the range of the base angle is about 60° to about 80°; or a second base angle of a corner pyramid structure among the second plurality of corner pyramid structures is defined as an inner angle relative to the second plane, and the range of the base angle is about 60° to about 80°.

[0014] Aspect 5. The display device according to aspect 4, wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures comprises a plurality of quadrangular pyramids. At least one of the first base angle or the second base angle ranges from 60° to 75°.

[0015] Aspect 6. The display device according to aspect 4, wherein at least one of the plurality of first pyramid structures or the second plurality of pyramid structures comprises a plurality of hexagonal pyramids. At least one of the first base angle or the second base angle ranges from 60° to 75°.

[0016] Aspect 7. A display device as described in any one of Aspects 1 to 3, wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures comprises a plurality of triangular pyramids. At least one of the following situations exists: a first base angle of a pyramid structure among the plurality of pyramid structures is defined as an inner angle relative to the first plane, and the range of the base angle is about 50° to about 80°; or a second base angle of a pyramid structure among the second plurality of pyramid structures is defined as an inner angle relative to the second plane, and the range of the base angle is about 50° to about 80°.

[0017] Aspect 8. The display device according to Aspect 7, wherein at least one of the first base angle or the second base angle ranges from about 50° to about 70°.

[0018] Aspect 9. A display device as described in any of Aspects 4-8, wherein the pyramid structure of at least one of the first plurality of pyramid structures or the second plurality of pyramid structures includes a height and a radius of curvature of a peak of the pyramid structure, and the radius of curvature is approximately 20% or less of the height.

[0019] Aspect 10. A display device as described in any of Aspects 4-9, wherein the first platform height of the first sheet between the light-emitting surface of the backlight device and the base of the pyramid structure in the first plurality of pyramid structures or the peak of the pyramid structure in the second plurality of pyramid structures ranges from about 0.5 microns to about 10 microns.

[0020] Aspect 11. A display device as described in any of Aspects 4-10, wherein the second platform height of the second sheet between the second plane and the peak of the pyramid structure in the first plurality of pyramid structures or the base of the pyramid structure in the second plurality of pyramid structures ranges from about 0.5 microns to about 10 microns.

[0021] Aspect 12. The display device of any one of Aspects 1-11, wherein the first refractive index is approximately 1.6 or greater, and the second refractive index is less than 1.6.

[0022] Aspect 13. The display device of any one of Aspects 1-11, wherein the second refractive index is approximately 1.6 or greater, and the first refractive index is less than 1.6.

[0023] Aspect 14. The display apparatus of any one of aspects 1-13, wherein the light extraction device has a haze of about 1% or less.

[0024] Aspect 15. The display device according to any one of aspects 1 to 14, wherein the light extraction device further comprises a substrate disposed on the second major surface of the second sheet.

[0025] Aspect 16. A display device as described in any of Aspects 1-15, wherein the backlight device includes a plurality of light sources. The backlight device includes a color converter, and the color converter includes a plurality of pixels positioned between the plurality of light sources and the light emitting surface. One pixel of the plurality of pixels includes three sub-pixels. Each sub-pixel is defined by a plurality of walls. One sub-pixel of the three sub-pixels includes a phosphor material layer and an absorptive color filter. The phosphor material layer is positioned between the plurality of light sources and the absorptive color filter. The main surface of the absorptive color filter and the main surfaces of the plurality of walls extend along a common plane.

[0026] Aspect 17. The display device of aspect 16, wherein the phosphorescent material layer comprises a quantum dot phosphor in a polymer matrix.

[0027] Aspect 18. The display device according to aspect 17, wherein the thickness of the phosphor material layer ranges from about 3 micrometers to about 10 micrometers.

[0028] Aspect 19. The display device of any one of Aspects 16-18, wherein the thickness of the sub-pixel ranges from about 8 microns to about 30 microns.

[0029] Aspect 20. A display device as described in any of Aspects 16-19, wherein the area of ​​the light emitting surface of the pixel corresponding to the major surface of the absorptive color filter of the three sub-pixels is about 50% or less. The light emitting surface is defined by the major surface of the absorptive color filter and the major surfaces of the plurality of walls.

[0030] Aspect 21. The display device of any one of aspects 16 to 19, wherein the backlight assembly further comprises a dichroic mirror positioned between the phosphor material layer and the plurality of light sources.

[0031] Aspect 22. The display device of any of Aspects 16-19, wherein the backlight further comprises a polarizer positioned between the absorptive color filter and the first sheet. The polarizer comprises the light emitting surface.

[0032] Aspect 23. A light extraction device, comprising: a first sheet, the first sheet comprising a first major surface, the first major surface extending along a first plane and arranged on the light emitting surface. The light extraction device comprises: a second sheet, the second sheet being arranged on the first sheet, the second sheet comprising a second major surface, the second major surface extending along a second plane parallel to the first plane. The first refractive index of the first sheet or the second refractive index of the second sheet is about 1.6 or greater. The absolute value of the difference between the first refractive index and the second refractive index is about 0.1 to about 0.4. At least one of the following situations exists: the first sheet comprises a first plurality of pyramid structures, and a first plurality of spaces between the first plurality of pyramid structures are filled by the second sheet; or the second sheet comprises a second plurality of pyramid structures, and a second plurality of spaces between the second plurality of pyramid structures are filled by the first sheet.

[0033] Aspect 24. The light extraction device of aspect 23, wherein the first refractive index or the second refractive index is about 1.65 to about 1.9.

[0034] Aspect 25. A light extraction device as described in any of Aspects 23-24, wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures includes a plurality of triangular pyramids, a plurality of quadrangular pyramids, a plurality of hexagonal pyramids, or a combination thereof arranged in a closely packed configuration.

[0035] Aspect 26. A light extraction device as described in any of Aspects 23-25, wherein the light extraction device includes at least one of the following: a first base angle of one of the first plurality of pyramid structures, the first base angle being defined as an inner angle relative to the first plane, the base angle ranging from about 60° to about 80°; or a second base angle of one of the second plurality of pyramid structures, the second base angle being defined as an inner angle relative to the second plane, the base angle ranging from about 60° to about 80°.

[0036] Aspect 27. The light extraction device of aspect 26, wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures comprises a plurality of quadrangular pyramids. At least one of the first base angle or the second base angle ranges from 60° to 75°.

[0037] Aspect 28. The light extraction device of aspect 26, wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures comprises a plurality of hexagonal pyramids. At least one of the first base angle or the second base angle ranges from 60° to 75°.

[0038] Aspect 29. A light extraction device as described in any of Aspects 23-25, wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures includes a plurality of triangular pyramids. The light extraction device includes at least one of the following: a first base angle of a pyramid structure among the plurality of pyramid structures, the first base angle being defined as an inner angle relative to the first plane, the base angle ranging from about 50° to about 80°; or a second base angle of a pyramid structure among the second plurality of pyramid structures, the second base angle being defined as an inner angle relative to the second plane, the base angle ranging from about 50° to about 80°.

[0039] Aspect 30. The light extraction device of aspect 29, wherein the at least one of the first base angle or the second base angle ranges from about 50° to about 70°.

[0040] Aspect 31. A light extraction device as described in any of Aspects 26-30, wherein the pyramid structure of at least one of the first plurality of pyramid structures or the second pyramid structure includes a height and a radius of curvature of a peak of the pyramid structure, and the radius of curvature is approximately 20% or less of the height.

[0041] Aspect 32. A light extraction device as described in any of Aspects 23-31, wherein the first platform height of the first sheet between the light-emitting surface of the backlight device and the base of the pyramid structure in the first plurality of pyramid structures or the peak of the pyramid structure in the second plurality of pyramid structures ranges from about 0.5 microns to about 10 microns.

[0042] Aspect 33. A light extraction device as described in any of Aspects 23-32, wherein the second platform height of the second sheet between the second plane and the peak of the pyramid structure in the first plurality of pyramid structures or the base of the pyramid structure in the second plurality of pyramid structures ranges from about 0.5 microns to about 10 microns.

[0043] Aspect 34. The light extraction device of any of Aspects 23-33, wherein the first refractive index is approximately 1.6 or greater and the second refractive index is less than 1.6.

[0044] Aspect 35. A light extraction device as described in any of Aspects 23-33, wherein the second refractive index is approximately 1.6 or greater and the first refractive index is less than 1.6.

[0045] Aspect 36. The light extraction device of any one of aspects 23-35, wherein the haze of the light extraction device is about 1% or less.

[0046] Aspect 37. A display device, comprising: a backlight device, the backlight device being configured to emit light through a light-emitting surface of the backlight device. The display device includes a light extraction device, the light extraction device including a first sheet. The first sheet includes a first major surface and a plurality of pyramid structures, the first major surface extending along a first plane. The first major surface is arranged on the light-emitting surface. The plurality of pyramid structures are opposite to the first plane. The light extraction device includes a second sheet arranged on the first sheet. The second sheet fills a plurality of spaces between the plurality of pyramid structures. The second sheet includes a second major surface extending along a second plane parallel to the first plane. The first refractive index of the first sheet ranges from about 1.65 to about 1.9. The second refractive index of the second sheet ranges from about 1.4 to about 1.6.

[0047] Aspect 38. The display device according to aspect 37, wherein a base angle of a pyramid structure among the plurality of pyramid structures is defined as an inner angle relative to the first plane, and the base angle ranges from about 60° to about 80°.

[0048] Aspect 39. The display device of any one of Aspects 37-38, wherein the first refractive index is in a range of about 1.7 to about 1.9.

[0049] Aspect 40. A display device, comprising: a backlight device, the backlight device being configured to emit light through the light-emitting surface of the backlight device. The display device includes a light extraction device, the light extraction device including a first sheet. The first sheet includes a first main surface and a plurality of pyramid structures, the first main surface extending along a first plane. The first main surface is arranged on the light-emitting surface. The plurality of pyramid structures are opposite to the first main surface. The light extraction device includes a second sheet arranged on the first sheet. The second sheet fills a plurality of spaces between the plurality of pyramid structures. The second sheet includes a second main surface extending along a second plane parallel to the first plane. The base angle of one of the plurality of pyramid structures is defined as an inner angle relative to the first plane, and the base angle ranges from about 60° to about 80°.

[0050] Aspect 41. The display device of aspect 40, wherein the first refractive index of the first sheet material is about 0.15 to about 0.4 greater than the second refractive index of the second sheet material.

[0051] Aspect 42. The display device of any one of Aspects 37-41, wherein the plurality of pyramid structures comprises a plurality of triangular pyramids, a plurality of quadrangular pyramids, a plurality of hexagonal pyramids, or a combination thereof arranged in a closely packed configuration.

[0052] Aspect 43. The display device according to aspect 38 or aspect 41, wherein the plurality of pyramid structures include a plurality of quadrangular pyramids, the first refractive index ranges from about 1.7 to about 1.9, and the base angle ranges from about 60° to about 75°.

[0053] Aspect 44. The display device of aspect 43, wherein the base angle ranges from about 65° to about 70°.

[0054] Aspect 45. The display device of any one of Aspects 43-44, wherein the first refractive index is in a range of about 1.75 to about 1.9.

[0055] Aspect 46. The display device according to aspect 37, wherein the plurality of pyramid structures include a plurality of triangular pyramids, and a base angle of a pyramid structure among the plurality of pyramid structures is defined as an inner angle relative to the first plane, and the base angle ranges from 50° to about 80°.

[0056] Aspect 47. The display device according to aspect 41, wherein the plurality of pyramid structures include a plurality of triangular pyramids. The first refractive index is in a range of about 1.65 to about 1.9.

[0057] Aspect 48. The display device according to aspect 38 or aspect 41, wherein the plurality of pyramid structures comprises a plurality of triangular pyramids. The first refractive index is in a range of about 1.75 to about 1.9.

[0058] Aspect 49. The display device according to aspect 38 or aspect 41, wherein the plurality of pyramid structures comprises a plurality of hexagonal pyramids. The first refractive index is in a range of about 1.65 to about 1.9.

[0059] Aspect 50. The display device of aspect 49, wherein the base angle ranges from about 60° to about 70°.

[0060] Aspect 51. A display device as described in any of Aspects 38, 40-41, 43-45 or 47-50, wherein the first platform height of the first sheet between the light emitting surface of the backlight device and the base of the pyramid structure ranges from about 0.5 microns to about 10 microns.

[0061] Aspect 52. The display device of any one of aspects 38, 40-41, 43-45, or 47-51, wherein the pyramid structure comprises a height, and a radius of curvature of a peak of the pyramid structure is about 20% or less of the height.

[0062] Aspect 53. The display device of any of Aspects 38, 40-41, 43-45, or 47-52, wherein the second plateau height of the second sheet between the second plane and the peak of the pyramid structure ranges from about 0.5 microns to about 10 microns.

[0063] Aspect 54. The display apparatus of any one of Aspects 37-53, wherein the haze of the light extraction device is about 1% or less.

[0064] Aspect 55. The display device of any one of Aspects 37-54, wherein the light extraction device further comprises a substrate disposed on the first major surface of the second sheet.

[0065] Aspect 56. A display device as described in any of Aspects 37-55, wherein the backlight device includes a plurality of light sources. The backlight device includes a color converter, and the color converter includes a plurality of pixels positioned between the plurality of light sources and the light emitting surface. One pixel of the plurality of pixels includes three sub-pixels. Each sub-pixel is defined by a plurality of walls. One sub-pixel of the three sub-pixels includes a phosphor material layer and an absorptive color filter. The phosphor material layer is positioned between the plurality of light sources and the absorptive color filter. The main surface of the absorptive color filter and the main surface of the plurality of walls extend along a common plane.

[0066] Aspect 57. The display device of aspect 56, wherein the phosphorescent material layer comprises a quantum dot phosphor in a polymer matrix.

[0067] Aspect 58. The display device of aspect 57, wherein the thickness of the phosphorescent material layer is in a range from about 3 micrometers to about 10 micrometers.

[0068] Aspect 59. The display device of any one of Aspects 56-58, wherein the thickness of the sub-pixel ranges from about 8 microns to about 30 microns.

[0069] Aspect 60. A display device as described in any of Aspects 56-59, wherein the area of ​​the light emitting surface of the pixel corresponding to the major surface of the absorptive color filter of the three sub-pixels is about 50% or less. The light emitting surface is defined by the major surface of the absorptive color filter and the major surfaces of the plurality of walls.

[0070] Aspect 61. The display device of any one of aspects 56-60, wherein the backlight assembly further comprises a dichroic mirror positioned between the phosphor material layer and the plurality of light sources.

[0071] Aspect 62. The display device of any of Aspects 56-60, wherein the backlight further comprises a polarizer positioned between the absorptive color filter and the first sheet. The polarizer comprises the light emitting surface.

[0072] Aspect 63. A light extraction device comprises a first sheet. The first sheet comprises a first major surface and a plurality of pyramid structures, the first major surface extending along a first plane. The light extraction device comprises a second sheet disposed on the first sheet. The second sheet fills a plurality of spaces between the plurality of pyramid structures. The second sheet comprises a second major surface extending along a second plane parallel to the first plane. The first refractive index of the first sheet ranges from about 1.65 to about 1.9. The second refractive index of the second sheet ranges from about 1.4 to about 1.6.

[0073] Aspect 64. The light extraction device of aspect 63, wherein a base angle of a pyramid structure among the plurality of pyramid structures is defined as an internal angle relative to the first plane, and the internal angle ranges from about 60° to about 80°.

[0074] Aspect 65. The light extraction device of any of Aspects 63-64, wherein the first refractive index is in a range of about 1.7 to about 1.9.

[0075] Aspect 66. A light extraction device comprises a first sheet. The first sheet comprises a first major surface and a plurality of pyramid structures, the first major surface extending along a first plane. The light extraction device comprises a second sheet disposed on the first sheet. The second sheet fills a plurality of spaces between the plurality of pyramid structures. The second sheet comprises a second major surface extending along a second plane parallel to the first plane. The base angle of a pyramid structure among the plurality of pyramid structures is defined as an inner angle relative to the first plane, the base angle ranging from about 60° to about 80°.

[0076] Aspect 67. The light extraction device of aspect 66, wherein the first refractive index of the first sheet is about 0.15 to about 0.4 greater than the second refractive index of the second sheet.

[0077] Aspect 68. The light extraction device of any one of Aspects 63-67, wherein the plurality of pyramid structures comprises a plurality of triangular pyramids, a plurality of quadrangular pyramids, a plurality of hexagonal pyramids, or a combination thereof arranged in a closely packed configuration.

[0078] Aspect 69. The light extraction device of aspect 63 or aspect 66, wherein the plurality of pyramid structures comprises a plurality of quadrangular pyramids. The first refractive index ranges from about 1.7 to about 1.9. The base angle ranges from about 60° to about 75°.

[0079] Aspect 70. The light extraction device of aspect 69, wherein the base angle ranges from about 65° to about 70°.

[0080] Aspect 71. The light extraction device of any of Aspects 69-70, wherein the first refractive index ranges from about 1.75 to about 1.9.

[0081] Aspect 72. The light extraction device of aspect 63, wherein the plurality of pyramid structures include a plurality of triangular pyramids. A base angle of a pyramid structure in the plurality of pyramid structures is defined as an inner angle relative to the first plane, and the base angle ranges from 50° to about 80°.

[0082] Aspect 73. The light extraction device of aspect 64, wherein the plurality of pyramid structures comprises a plurality of triangular pyramids. The first refractive index is in a range of about 1.65 to about 1.9.

[0083] Aspect 74. The light extraction device of aspect 64 or aspect 67, wherein the plurality of pyramid structures comprises a plurality of triangular pyramids. The first refractive index ranges from about 1.75 to about 1.9.

[0084] Aspect 75. The light extraction device of aspect 64 or aspect 67, wherein the plurality of pyramid structures comprises a plurality of hexagonal pyramids. The first refractive index is in a range of about 1.65 to about 1.9.

[0085] Aspect 76. The light extraction device of aspect 75, wherein the base angle ranges from about 60° to about 70°.

[0086] Aspect 77. The light extraction device of any of aspects 64, 66-67, 69-71, or 73-76, wherein the first terrace height of the first sheet ranges from about 0.5 microns to about 10 microns.

[0087] Aspect 78. A light extraction device as described in any of aspects 64, 66-67, 69-71 or 73-77, wherein the pyramid structure includes a height, and the radius of curvature of the peak of the pyramid structure is about 20% or less of the height.

[0088] Aspect 79. The light extraction device of any of Aspects 64, 66-67, 69-71, or 73-78, wherein the second plateau height of the second sheet between the second plane and the peak of the pyramid structure ranges from about 0.5 microns to about 10 microns.

[0089] Aspect 80. The light extraction device of any one of aspects 63-79, wherein the haze of the light extraction device is about 1% or less.

[0090] Aspect 81. A display device, comprising: a backlight device, the backlight device being configured to emit light through a light emitting surface of the backlight device. The display device includes a light extraction device, the light extraction device including a first sheet, the first sheet including a first major surface extending along a first plane and arranged on the light emitting surface. The light extraction device includes a second sheet arranged on the first sheet. The second sheet includes a plurality of pyramid structures. The second sheet includes a second major surface extending along a second plane parallel to the first plane. The first sheet fills a plurality of spaces between the plurality of pyramid structures. The second refractive index of the second sheet ranges from about 1.65 to about 1.9. The first refractive index of the first sheet ranges from about 1.4 to about 1.6.

[0091] Aspect 82. The display device according to aspect 81, wherein a base angle of a pyramid structure among the plurality of pyramid structures is defined as an inner angle relative to the second plane, and the base angle ranges from about 60° to about 75°.

[0092] Aspect 83. A display device as described in any of Aspects 81-82, wherein the first refractive index ranges from about 1.7 to about 1.9.

[0093] Aspect 84. A display device, comprising: a backlight device, the backlight device being configured to emit light through a light-emitting surface of the backlight device. The display device comprises a light extraction device, the light extraction device comprising a first sheet, the first sheet comprising a first main surface extending along a first plane and arranged on the light-emitting surface. The light extraction device comprises a second sheet arranged on the first sheet. The second sheet comprises a plurality of pyramid structures. The second sheet comprises a second main surface extending along a second plane parallel to the first plane. The first sheet fills a plurality of spaces between the plurality of pyramid structures. The base angle of a pyramid structure among the plurality of pyramid structures is defined as an inner angle relative to the second plane, and the base angle ranges from about 60° to about 75°.

[0094] Aspect 85. The display device of aspect 84, wherein the second refractive index of the second sheet material is about 0.15 to about 0.4 greater than the first refractive index of the first sheet material.

[0095] Aspect 86. A display device as described in any of Aspects 81-85, wherein the plurality of pyramid structures include a plurality of triangular pyramids, a plurality of quadrangular pyramids, a plurality of hexagonal pyramids, or a combination thereof arranged in a closely packed configuration.

[0096] Aspect 87. The display device according to aspect 82 or aspect 86, wherein the plurality of pyramid structures include a plurality of quadrangular pyramids, the second refractive index ranges from about 1.7 to about 1.9, and the base angle ranges from about 60° to about 75°.

[0097] Aspect 88. The display device of aspect 87, wherein the base angle ranges from about 70° to about 75°.

[0098] Aspect 89. The display device of any of Aspects 87-88, wherein the second refractive index is in the range of about 1.75 to about 1.9.

[0099] Aspect 90. The display device of Aspect 81, wherein the plurality of pyramid structures include a plurality of triangular pyramids, and a base angle of a pyramid structure among the plurality of pyramid structures is defined as an inner angle relative to the second plane, and the base angle ranges from 50° to about 70°.

[0100] Aspect 91. The display device of aspect 85, wherein the plurality of pyramid structures comprises a plurality of triangular pyramids. The second refractive index is in a range of about 1.65 to about 1.9.

[0101] Aspect 92. The display device of aspect 82 or aspect 85, wherein the plurality of pyramid structures comprises a plurality of triangular pyramids. The second refractive index is in a range of about 1.75 to about 1.9.

[0102] Aspect 93. The display device of aspect 82 or aspect 85, wherein the plurality of pyramid structures comprises a plurality of hexagonal pyramids. The second refractive index is in a range of about 1.65 to about 1.9.

[0103] Aspect 94. The display device of Aspect 93, wherein the base angle ranges from about 60° to about 70°.

[0104] Aspect 95. A display device as described in any of Aspects 82, 84-85, 87-89 or 91-94, wherein the first platform height of the first sheet between the light emitting surface of the backlight device and the peak of the pyramid structure ranges from about 0.5 microns to about 10 microns.

[0105] Aspect 96. The display device of any one of Aspects 82, 84-85, 87-89 or 91-94, in yet a further aspect, the pyramid structure comprises a height and a radius of curvature of a peak of the pyramid structure, the radius of curvature being approximately 20% or less of the height.

[0106] Aspect 97. The display device of any of Aspects 82, 84-85, 87-89, or 91-94, wherein a second terrace height of the second sheet between the second plane and the base of the pyramid structure ranges from about 0.5 microns to about 10 microns.

[0107] Aspect 98. The display apparatus of any one of Aspects 81-97, wherein the haze of the light extraction device is about 1% or less.

[0108] Aspect 99. The display device of any one of Aspects 81-98, wherein the light extraction device further comprises a substrate disposed on the first major surface of the second sheet.

[0109] Aspect 100. A display device as described in any of Aspects 81-99, wherein the backlight device includes a plurality of light sources. The backlight device includes a color converter, and the color converter includes a plurality of pixels positioned between the plurality of light sources and the light emitting surface. One pixel of the plurality of pixels includes three sub-pixels. Each sub-pixel is defined by a plurality of walls. One sub-pixel of the three sub-pixels includes a phosphor material layer and an absorptive color filter. The phosphor material layer is positioned between the plurality of light sources and the absorptive color filter. The main surface of the absorptive color filter and the main surface of the plurality of walls extend along a common plane.

[0110] Aspect 101. The display device of aspect 100, wherein the phosphorescent material layer comprises a quantum dot phosphor in a polymeric matrix.

[0111] Aspect 102. The display device of aspect 101, wherein the thickness of the phosphorescent material layer is in a range from about 3 micrometers to about 10 micrometers.

[0112] Aspect 103. A display device as described in any of Aspects 100-102, wherein the thickness of the sub-pixel ranges from about 8 microns to about 30 microns.

[0113] Aspect 104. A display device as described in any of Aspects 100-103, wherein the area of ​​the light emitting surface of the pixel corresponding to the major surface of the absorptive color filter of the three sub-pixels is about 50% or less. The light emitting surface is defined by the major surface of the absorptive color filter and the major surfaces of the plurality of walls.

[0114] Aspect 105. The display device of any one of aspects 100-103, wherein the backlight assembly further comprises a dichroic mirror positioned between the phosphor material layer and the plurality of light sources.

[0115] Clause 106. The display device of any of Clauses 100-103, wherein the backlight further comprises a polarizer positioned between the absorptive color filter and the first sheet, and the polarizer comprises the light emitting surface.

[0116] Aspect 107. A light extraction device comprises a first sheet material, the first sheet material comprising a first major surface extending along a first plane. The light extraction device comprises a second sheet material disposed on the first sheet material. The second sheet material comprises a plurality of pyramid structures. The second sheet material comprises a second major surface extending along a second plane parallel to the first plane. The first sheet material fills a plurality of spaces between the plurality of pyramid structures. The second refractive index of the second sheet material ranges from about 1.65 to about 1.9. The first refractive index of the first sheet material ranges from about 1.4 to about 1.6.

[0117] Aspect 108. The light extraction device of aspect 107, wherein a base angle of a pyramid structure among the plurality of pyramid structures is defined as an internal angle relative to the second plane, and the internal angle ranges from about 60° to about 75°.

[0118] Aspect 109. The light extraction device of any of aspects 107-108, wherein the second refractive index is in a range of about 1.7 to about 1.9.

[0119] Aspect 110. A light extraction device comprises a first sheet material, the first sheet material comprising a first major surface extending along a first plane. The light extraction device comprises a second sheet material disposed on the first sheet material. The second sheet material comprises a plurality of pyramid structures. The second sheet material comprises a first major surface extending along a second plane parallel to the first plane. The first sheet material fills a plurality of spaces between the plurality of pyramid structures. The base angle of a pyramid structure among the plurality of pyramid structures is defined as an inner angle relative to the second plane, the base angle ranging from about 60° to about 75°.

[0120] Aspect 111. The light extraction device of aspect 110, wherein the second refractive index of the second sheet material is about 0.15 to about 0.4 greater than the first refractive index of the first sheet material.

[0121] Aspect 112. The light extraction device as described in any of aspects 107-111, the plurality of pyramid structures include a plurality of triangular pyramids, a plurality of quadrangular pyramids, a plurality of hexagonal pyramids, or a combination thereof arranged in a closely packed configuration.

[0122] Aspect 113. The light extraction device of aspect 108 or aspect 111, wherein the plurality of pyramid structures comprises a plurality of quadrangular pyramids. The second refractive index is in a range of about 1.7 to about 1.9. The base angle is in a range of about 60° to about 75°.

[0123] Aspect 114. The light extraction device of aspect 113, wherein the base angle ranges from about 70° to about 75°.

[0124] Aspect 115. The light extraction device of any of Aspects 113-114, wherein the second refractive index is in a range of about 1.75 to about 1.9.

[0125] Aspect 116. The light extraction device of aspect 107, wherein the plurality of pyramid structures include a plurality of triangular pyramids. A base angle of a pyramid structure in the plurality of pyramid structures is defined as an inner angle relative to the second plane, and the base angle ranges from 50° to about 70°.

[0126] Aspect 117. The light extraction device of aspect 108, wherein the plurality of pyramid structures comprises a plurality of triangular pyramids. The second refractive index is in a range of about 1.65 to about 1.9.

[0127] Aspect 118. The light extraction device of aspect 108 or aspect 111, wherein the plurality of pyramid structures comprises a plurality of triangular pyramids. The second refractive index is in a range of about 1.75 to about 1.9.

[0128] Aspect 119. The light extraction device of aspect 108 or aspect 111, wherein the plurality of pyramid structures comprises a plurality of hexagonal pyramids. The second refractive index is in a range of about 1.65 to about 1.9.

[0129] Aspect 120. The light extraction device of aspect 119, wherein the base angle is in a range of about 60° to about 70°.

[0130] Aspect 121. The light extraction device of any of aspects 108, 110-111, 113-115, or 117-120, wherein the first sheet has a first terrace height between the first plane and the peak of the pyramid structure in a range of about 0.5 microns to about 10 microns.

[0131] Aspect 122. The light extraction device of any of Aspects 108, 110-111, 113-115, or 117-121, wherein the pyramid structure comprises a height and a radius of curvature of a peak of the pyramid structure, the radius of curvature being approximately 20% or less of the height.

[0132] Aspect 123. The light extraction device of any of Aspects 108, 110-111, 113-115, or 117-122, wherein the second plateau height of the second sheet between the second plane and the base of the pyramid structure ranges from about 0.5 microns to about 10 microns.

[0133] Aspect 124. The light extraction device of any one of aspects 107-123, wherein the haze of the light extraction device is about 1% or less.

[0134] Additional features and advantages of the various aspects disclosed herein will be set forth in the following detailed description, and those skilled in the art will understand in part these features and advantages from this description, or recognize these features and advantages by practicing the various aspects described herein, which include the following detailed description, the claims, and the accompanying drawings. It is to be understood that the aspects presented in the foregoing general description and the following detailed description are intended to provide an overview or framework for understanding the nature and characteristics of the aspects disclosed herein. The accompanying drawings are included to provide further understanding, and these drawings are incorporated into and constitute a part of this specification. These drawings illustrate various aspects of the present disclosure and, together with the description, explain the principles and operation of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0135] These and other features, aspects and advantages will be better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0136] Figure 1Schematically illustrates an exemplary embodiment of a display device including a light extraction device and a backlight device according to various aspects of the present disclosure;

[0137] Figure 2 Schematically illustrates an exemplary embodiment of a display device including a light extraction device and a backlight device including a dichroic mirror and a polarizer according to various aspects of the present disclosure;

[0138] Figure 3 Schematically illustrates exemplary embodiments of light extraction devices according to various aspects of the present disclosure;

[0139] Figure 4-5 Schematically illustrates Figure 1 and Figure 3 Vision Figure 4 The pyramid structure shown;

[0140] Figure 6-8 Schematically illustrates the Figure 1 and Figure 3 A plurality of pyramid structures intercepted by line 6-6;

[0141] Fig. 9 Schematically illustrates the Figure 1 A pixel captured by line 9-9 in , wherein the pixel includes three sub-pixels;

[0142] Figure 10-11 schematically illustrates relative brightness of a plurality of quadrangular pyramids as a function of viewing angle, wherein a first sheet includes a greater refractive index than a second sheet;

[0143] Figure 12-13 schematically illustrates relative brightness of a plurality of triangular pyramids as a function of viewing angle, wherein a first sheet includes a greater refractive index than a second sheet;

[0144] Figure 14-15 schematically illustrates relative brightness of a plurality of hexagonal pyramids as a function of viewing angle, wherein a first sheet includes a greater refractive index than a second sheet;

[0145] Fig.16 Schematically illustrates the relative brightness of multiple rounded pyramids as a function of viewing angle;

[0146] Fig.17 Schematically illustrates the relative brightness at the peaks of multiple rounded cones as a function of the radius of curvature;

[0147] Figure 18-19 schematically illustrates relative brightness of a plurality of quadrangular pyramids as a function of viewing angle, wherein the second sheet includes a greater refractive index than the first sheet;

[0148] Figure 20-21 schematically illustrates relative brightness of a plurality of triangular pyramids as a function of viewing angle, wherein the second sheet includes a greater refractive index than the first sheet; and

[0149] Figure 22-23 The relative brightness of a plurality of hexagonal pyramids as a function of viewing angle is schematically illustrated, wherein the second sheet comprises a greater refractive index than the first sheet.

[0150] Throughout the disclosure, the accompanying drawings are used to emphasize certain aspects. Therefore, unless otherwise explicitly stated, the relative sizes of various regions, parts, and substrates shown in the accompanying drawings should not be assumed to be proportional to their actual relative sizes. DETAILED DESCRIPTION

[0151] Various aspects will now be described more fully below with reference to the accompanying drawings, in which exemplary aspects are shown. Where possible, the same reference numerals are used throughout the drawings to refer to the same or similar parts. However, the present disclosure may be implemented in many different forms, and the present disclosure should not be considered limited to the aspects set forth herein.

[0152] This disclosure relates to Figure 3 The light extraction device 301 and / or Figure 1-2 The light extraction device 121 in the display devices 101 and 201 shown. For example, Figure 1-3 A first sheet 123 and a second sheet 133 are illustrated. The first sheet 123 may include a plurality of pyramid structures 122, and the second sheet 133 may fill a plurality of spaces 132 between the plurality of pyramid structures 122. Alternatively or additionally, the second sheet 133 may include a plurality of pyramid structures 152, and the first sheet 123 may fill a plurality of spaces 162 between the plurality of pyramid structures 152. Unless otherwise noted, the discussion of features of various aspects of the light extraction device may be equally applicable to corresponding features of other light extraction devices (such as light extraction devices in light extraction apparatuses and / or display devices). Figure 1-2 As shown, the light extraction device 121 can be used in combination with the backlight devices 102 and 202, which can provide a direct-view display. In various aspects, the light extraction device can be used in a wide range of display applications, such as liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light emitting diode displays (OLEDs), plasma display panels (PDPs), or similar applications. Such display applications can, for example, be incorporated into mobile phones, tablet computers, laptops, watches, wearables, and / or monitors or displays with touch capabilities.

[0153] like Figure 1-3Schematically illustrated, the light extraction device 121 comprises a first sheet 123 comprising a first major surface 127 . The first major surface 127 is opposite to the second patterned surface 125 and may extend along a first plane 126 .

[0154] like Figure 1-3 As shown, the light extraction device 121 includes a second sheet 133, the second sheet includes a second major surface 135, the second major surface is opposite to the first patterned surface 137 and can extend along a second plane 136. The second plane 136 can be parallel to the first plane 126, and the first major surface 127 extends along the first plane. The second sheet 133 is disposed on the second patterned surface 125 of the first sheet 123. For example, the first patterned surface 137 can be in contact with the second patterned surface 125.

[0155] In various aspects, such as Figure 1-3 As shown, the first sheet 123 includes a second patterned surface 125, and the second patterned surface includes a plurality of pyramid structures 122. Figure 1-5 As shown, one of the plurality of pyramid structures 122, a pyramid structure 126a, includes nadir points 402a and 402b at the periphery of the pyramid structure 126a. The third plane 124 is defined by the nadir points 402a and 402b of the plurality of pyramid structures 122, thereby corresponding to the bottom of the pyramid structure 126a. Therefore, the plurality of pyramid structures 122 extend from the third plane 124, away from the first major surface 127 (such as the first plane 126). The third plane 124 may be parallel to the first plane 126 and / or the second plane 136. The second sheet 133 may fill the plurality of spaces 132 between the plurality of pyramid structures 122. Filling the plurality of spaces with the second sheet may reduce light scattering at the second patterned surface, which may reduce haze, improve image resolution, and increase the brightness of light extracted from the light extraction device. Throughout the disclosure, the base angle 401 of the pyramid structure 126a is defined as the inner angle between the second patterned surface 125 and the first major surface 127 (i.e., the first plane 126). Figure 1-5 124, and thus the base angle 401 of the pyramid structure 126a is shown as the inner angle between the second patterned surface 125 and the third plane 124, which is equal to the inner angle between the second patterned surface 125 and the first major surface 127 (ie, the first plane 126).

[0156] Alternatively or additionally, such as Figure 1-3As shown, the second sheet 133 includes a first patterned surface 137, and the first patterned surface includes a plurality of pyramid structures 152. One pyramid structure 156a of the plurality of pyramid structures 152 includes nadir points 154a and 154b at the periphery of the pyramid structure 156a. The fourth plane 134 is defined by the nadir points 154a and 154b of the plurality of pyramid structures 152, thereby corresponding to the bottom of the pyramid structure 156a. Therefore, the plurality of pyramid structures 152 extend from the fourth plane 134 away from the second major surface 135. The fourth plane 134 can be parallel to the third plane 124, the first plane 126, and / or the second plane 136. The first sheet 123 can fill a plurality of spaces 162 between the plurality of pyramid structures 152. Filling the plurality of spaces with the first sheet can reduce light scattering at the second patterned surface, which can reduce haze, improve image resolution, and increase the brightness of light extracted from the light extraction device. Throughout the disclosure, the base angle 409 of the pyramid structure 156a is defined as the inner angle between the first patterned surface 137 and the second major surface 135 (i.e., the second plane 136). Figure 1-3 134, and thus the base angle 409 of the pyramid structure 156a is shown as the inner angle between the first patterned surface 137 and the fourth plane 134, which is equal to the inner angle between the first patterned surface 137 and the second major surface 135 (ie, the second plane 136).

[0157] Base angles 401 and / or 409 may be about 50° or more, about 55° or more, about 60° or more, about 62° or more, about 65° or more, about 80° or less, about 78° or less, about 75° or less, about 72° or less, or about 70° or less. For example, base angles 401 and / or 409 may range from about 50° to about 80°, about 55° to about 80°, about 60° to about 80°, about 60° to about 78°, about 60° to about 75°, about 62° to about 75°, about 65° to about 75°, about 65° to about 72°, about 65° to about 70°, or any range or sub-range therebetween. Pyramids having base angles approaching 90° (e.g., about 80° or more) may be more expensive and / or more difficult to manufacture, and may use more material, than pyramids having smaller base angles. Providing a base angle of about 60° or greater (e.g., about 65° or greater, about 70° or greater, about 75° or greater) can increase the brightness of light extracted from the light extraction device, for example by reducing TIR. As discussed with respect to the examples below, providing a base angle within one or more of the above ranges can provide an unexpected benefit of increasing the brightness of light extracted from a light extraction device (e.g., a light extraction device, a display device). Figure 1-3As shown, display devices 101 and 201 and / or light extraction device 301 (eg, light extraction device 121 ) may include both a plurality of pyramid structures 122 and a plurality of pyramid structures 152 , and base angle 401 may be substantially equal to base angle 409 .

[0158] Throughout the disclosure, the refractive index of the material is measured according to ASTM E1967-19, wherein the first wavelength includes 589 nanometers. The first sheet 123 includes a first refractive index and the second sheet 133 includes a second refractive index. The first refractive index or the second refractive index can be about 1.6 or greater, about 1.65 or greater, about 1.67 or greater, about 1.7 or greater, about 1.72 or greater, about 1.75 or greater, about 1.9 or less, about 1.88 or less, about 1.85 or less, or about 1.8 or less. For example, the range of the first refractive index or the second refractive index can be about 1.6 to about 1.9, about 1.65 to about 1.9, about 1.67 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.9, about 1.75 to about 1.9, about 1.75 to about 1.88, about 1.75 to about 1.85, about 1.75 to about 1.8, or any range or sub-range therebetween. In various aspects, other refractive indices (such as the first refractive index, the second refractive index). Providing a high refractive index (e.g., about 1.6 or greater, about 1.65 or greater, about 1.7 or greater, or about 1.75 or greater) can increase the brightness of the light extracted from the light extraction device. Providing a high refractive index (e.g., about 1.9 or less, about 1.88 or less, about 1.85 or less, about 1.8 or less) can increase the brightness of the light extracted from the light extraction device.

[0159] In various aspects, other refractive indices (e.g., first refractive index, second refractive index) include second refractive indices of about 1.4 or greater, about 1.45 or greater, about 1.48 or greater, about 1.6 or less, about 1.55 or less, or about 1.53 or less. For example, other refractive indices (e.g., first refractive index, second refractive index) may range from about 1.4 to about 1.6, about 1.45 to about 1.55, about 1.48 to about 1.53, or any range or sub-range therebetween. Providing a lower refractive index within one or more of the above ranges may increase the brightness of light extracted from the light extraction device. The absolute value of the difference between the first refractive index and the second refractive index can be about 0.1 or greater, 0.15 or greater, about 0.18 or greater, about 0.20 or greater, about 0.22 or greater, about 0.25 or greater, about 0.27 or greater, about 0.40 or less, about 0.38 or less, about 0.35 or less, about 0.33 or less, or about 0.30 or less. For example, the absolute value of the difference between the first refractive index and the second refractive index can range from about 0.1 to about 0.4, about 0.15 to about 0.4, about 0.18 to about 0.4, about 0.20 to about 0.38, about 0.22 to about 0.35, about 0.25 to about 0.33, about 0.27 to about 0.30, or any range or sub-range therebetween. Providing an absolute value of the difference between the first refractive index and the second refractive index within one or more of the above ranges can increase the brightness of the light extracted from the light extraction device.

[0160] As discussed below with respect to examples, providing a high refractive index within one or more of the above ranges (e.g., in combination with an absolute difference between the first refractive index and the second refractive index within one or more corresponding ranges) can provide an unexpected benefit of increasing the brightness of light extracted from a light extraction device (e.g., a light extraction device, a display device). Brightness, as used herein, refers to the brightness per unit area (e.g., square meters (m2)). 2 )) of light intensity (e.g., candlelight). The brightness of the light extraction device is measured relative to a planar monolithic material layer with a refractive index of 1.5 and a thickness equal to the thickness of the corresponding light extraction device in a ray tracing simulation using Synopsis Light Tools software. The brightness can be measured experimentally in the normal direction of the second major surface of the second sheet of the light extraction device using a light meter positioned 1 meter from the second major surface.

[0161] Figure 6-8 Shows along Figure 1 or Figure 3 The second patterned surface 125 is intercepted by line 6-6 in FIG. In various aspects, as Figure 6-8As shown, the plurality of pyramid structures 122 may be arranged in a substantially closely packed configuration and / or a closely packed configuration. As used herein, the plurality of pyramid structures 122 being substantially closely packed means that 98% or more of the area in the third plane 124 corresponds to the plurality of pyramid structures 122, wherein the area of ​​the pyramid structure 126a is defined as the area bounded by the nadir points 402a and 402b. Figure 1-3 The nadir points 402a and 402b in Figure 6-8 As used herein, closely spaced means that 100% of the area in the third plane 124 corresponds to the plurality of pyramid structures, and the adjacent pyramid structures share a common nadir point (e.g., the pyramid structure 126a and the pyramid structure 126b both share the nadir point 402b). For example, the plurality of pyramid structures 122 may include a plurality of quadrangular pyramids 601 (see Figure 6 ), multiple triangular pyramids 701 (see Figure 7 ), multiple hexagonal cones 801 (see Figure 8 ) or a combination thereof, the pyramids may be arranged in a closely packed configuration. It should be understood that in various aspects, the first patterned surface 137 may be as Figure 6-8As shown, the plurality of pyramid structures 152 may include any configuration (e.g., substantially closely arranged) and / or pyramid structure type (e.g., triangular pyramid, square pyramid, hexagonal pyramid) discussed above in this paragraph with respect to the second patterned surface 125 and the plurality of pyramid structures 122. As used herein, the plurality of pyramid structures 152 are substantially closely arranged meaning that 98% or more of the area in the fourth plane 134 corresponds to the plurality of pyramid structures 152, wherein the area of ​​the pyramid structure 156a is defined as the area bounded by the nadir points 154a and 154b. In various aspects, the pyramid structures 126a and / or 156a (or multiple pyramid structures 122) may include a quadrangular pyramid 603 whose base angle 401 ranges from about 60° to about 80°, about 60° to about 75°, about 62° to about 75°, about 65° to about 75°, about 65° to about 75°, about 65° to about 72°, or about 65° to about 70°, and / or the first refractive index of the first sheet 123 may range from about 1.65 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.85, or about 1.75 to about 1.85. In various aspects, the pyramid structures 126a and / or 156a (or multiple pyramid structures 122) may include a triangular pyramid 703 whose base angle 401 ranges from about 50° to about 80°, about 50° to about 75°, about 50° to about 70°, about 55° to about 70°, or about 60° to about 65°, and / or the first refractive index of the first sheet 123 may range from about 1.65 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.9, or about 1.75 to about 1.9. In various aspects, the pyramid structures 126a and / or 156a (or multiple pyramid structures 122) may include a hexagonal pyramid 803 whose base angle 401 ranges from about 60° to about 80°, about 60° to about 78°, about 60° to about 75°, about 60° to about 72°, or about 60° to about 70°, and / or the first refractive index of the first sheet 123 may range from about 1.65 to about 1.9, about 1.67 to about 1.9, about 1.7 to about 1.9, about 1.7 to about 1.88, or about 1.68 to about 1.88.

[0162] like Figure 1-5 As shown, pyramid structure 126a includes peaks 128 that are opposite nadir points 402a and 402b. Figure 5 As shown, peak 128 may include rounded peak 506, which may be characterized by radius of curvature 507. Although a single radius of curvature 507 is discussed, the following discussion may also apply to any radius of curvature (e.g., maximum radius) and / or all radii of curvature of the pyramid structure if the rounded peak is not rotationally symmetric. Figure 5 As shown, the rounded peak 506 may include a rounded height 505 that is less than the pyramid height 405 of a pyramid structure without a rounded peak (as shown in dashed line structure 508). Figure 4 or Figure 5 As shown by the dashed structure 508, the cone height 405 is defined between the third plane 124 and the vertex 404 of the non-rounded cone. As used herein, the rounded height 505 is defined between the third plane 124 and the point on the second patterned surface 125 that corresponds to the radius of curvature 507 and is farthest from the third plane 124.

[0163] The ratio of the radius of curvature 507 to the height (e.g., fillet height 505 and / or pyramid height 405) can be about 0.20 or less, about 0.18 or less, about 0.15 or less, about 0.12 or less, about 0.10 or less, 0 or more, about 0.01 or more, about 0.02 or more, about 0.05 or more, or about 0.07 or more. For example, the ratio of the radius of curvature 507 to the height (e.g., fillet height 505 and / or pyramid height 405) can range from 0 to about 0.20, about 0.01 to about 0.18, about 0.02 to about 0.15, about 0.05 to about 0.12, about 0.08 to about 0.10, or any range or sub-range therebetween. In various aspects, as Figure 4 As shown, the pyramid structure 126a can include vertices 404, which can correspond to a radius of curvature of 0, thereby forming a non-rounded peak and a pyramid height 405 defined between the vertices 404. As discussed below with respect to examples, providing a ratio of radius of curvature to height within one or more of the above ranges can provide an unexpected benefit of increasing the brightness of light extracted from a light extraction device (e.g., a light extraction device, a display device) (e.g., in combination with one or both of the refractive index ranges or base angle ranges discussed above).

[0164] like Figure 4-5 As shown, the pyramid width 403 of the pyramid structure 126a is defined as the maximum distance between the nadir points 402a and 402b of the corresponding pyramid structure. The ratio of the height (such as the rounded corner height 505 and / or the pyramid height 405) to the pyramid width 403 can be about 0.6 or greater, about 0.9 or greater, about 1 or greater, about 1.1 or greater, about 2.9 or less, about 2 or less, or about 1.5 or less. For example, the range of the ratio of the height (such as the rounded corner height 505 and / or the pyramid height 405) to the pyramid width 403 can be about 0.6 to about 2.9, about 0.9 to about 2.9, about 1 to about 2.9, about 1 to about 2, about 1 to about 1.5, or any range or sub-range therebetween. As described below with respect to the examples, providing a ratio of the height to the width of the pyramid structure within one or more of the above ranges can provide an unexpected benefit, namely, increasing the brightness of light extracted from a light extraction device (such as a light extraction device, a display device).

[0165] In various aspects, such as Figure 1-3As shown, the pyramid structures 126a and 126b in the plurality of pyramid structures 122 may include the same dimensions (e.g., pyramid height, rounded corner height, pyramid width, radius of curvature at the peak, ratio of radius of curvature to pyramid height, ratio of radius of curvature to rounded corner height), base angle, and / or refractive index as each other. In addition, the pyramid structures 156a and 156b in the plurality of pyramid structures 152 may include the same dimensions (e.g., pyramid height, rounded corner height, pyramid width, radius of curvature at the peak, ratio of radius of curvature to pyramid height, ratio of radius of curvature to rounded corner height), base angle, and / or refractive index as each other.

[0166] like Figure 1-3 As shown, the pyramid structure 156a in the plurality of pyramid structures 152 includes a peak 158 opposite to the nadir points 154a and 154b. In various aspects, the peak 158 may include a rounded peak, the rounded peak may be characterized by a radius of curvature, and the ratio of the radius of curvature to the corresponding pyramid height or the corresponding rounded height may be within one or more corresponding ranges discussed above. The ratio of the height (e.g., rounded height, pyramid height) of the pyramid structure 156a to the pyramid width may be within one or more corresponding ranges discussed above.

[0167] like Figure 1-3 As shown, the first platform height 129 is the minimum distance between the first major surface 127 (i.e., the first plane 126) and the third plane 124 (e.g., the base of the pyramid structure 126a corresponding to the nadir points 402a and 402b, the peak 158 of the pyramid structure 156a) in the direction perpendicular to the first plane 126. The first platform height 129 can be about 0.5 micrometers (μm) or more, about 1 micrometer or more, about 2 micrometers or more, about 10 micrometers or less, about 8 micrometers or less, or about 5 micrometers or less. For example, the first platform height 129 can range from about 0.5 micrometers to about 10 micrometers, about 1 micrometer to about 8 micrometers, about 2 micrometers to about 5 micrometers, or any range or sub-range therebetween.

[0168] like Figure 1-3 As shown, the second platform height 139 is the minimum distance between the second major surface 135 and the fourth plane 134 (e.g., the peak 128 of the pyramid structure 126a, the base of the pyramid structure 156a corresponding to the nadir points 154a and 154b) in the direction perpendicular to the second plane 136. The second platform height 139 can be within one or more ranges discussed above for the first platform height 129.

[0169] In various aspects, such as Figure 1-3As shown, the display devices 101 and 201 and / or the light extraction device 301 (e.g., the light extraction device 121) can further include a substrate 143 disposed on the second major surface 135 of the second sheet 133. The substrate 143 can include a third major surface 145 opposite to the fourth major surface 147. The fourth major surface 147 can be attached to and / or contact the second major surface 135 and / or extend along the second plane 136. The substrate thickness 149, defined as the average distance between the third major surface and the fourth major surface, can be about 10 microns or more, about 100 microns or more, about 300 microns or more, about 5 millimeters (mm) or less, about 3 mm or less, or about 1 mm or less. For example, the range of the substrate thickness 149 can be about 10 microns to about 5 mm, about 100 microns to about 3 mm, about 300 microns to about 1 mm, or any range or sub-range therebetween.

[0170] In various aspects, the first sheet 123, the second sheet 133 and / or the substrate 143 may include a glass material, a ceramic material and / or a polymer material. The polymer material may include an optically colorless polymer, for example, siloxane (e.g., poly(dimethylsiloxane) (PDMS)), acrylate (e.g., poly(methyl methacrylate) (PMMA)), polystyrene (PS), polycarbonate (PC), polyimide (PI) or copolymers thereof (e.g., poly(methyl methacrylate-co-styrene)). As used herein, "optically transparent" or "optically colorless" means an average transmittance of 70% or more through a 1.0 mm thick block of material in the wavelength range of 400 nm to 700 nm, where the thickness is measured along the path length of light through the sheet of material. As used herein, the average transmittance of a material is measured by averaging the optical wavelengths in the range of 400 nm to 700 nm through a 1.0 mm thick block of material, which includes measuring the transmittance of integer wavelengths from about 400 nm to about 700 nm and averaging these measurements. Unless otherwise specified, the "transmittance" of a material refers to the average transmittance of the material. In various aspects, the average transmittance of an "optically transparent material" or "optically colorless material" through a 1.0 mm thick block of material in the wavelength range of 400 nm to 700 nm can be 75% or more, 80% or more, 85% or more, or 90% or more, 92% or more, 94% or more, 96% or more.

[0171] As used herein, "glass" refers to glass that includes at least 30 mole percent (mol%) silicon oxide (SiO 2) of an amorphous material. An amorphous material (e.g., glass) may be strengthened. As used herein, the term "strengthening" may refer to a material that has been chemically strengthened, such as by ion exchange of larger ions with smaller ions in the material. However, other strengthening methods (e.g., thermal tempering, or using the mismatch in thermal expansion coefficients between sheet portions to produce compressive stress and central tension regions) may be used to form a strengthened sheet. Exemplary glass materials that may be free of lithium oxide or contain lithium oxide may include soda-lime glass, alkali-aluminosilicate glass, alkali-containing borosilicate glass, alkali-containing aluminoborosilicate glass, alkali-containing phosphosilicate glass, and alkali-containing aluminophosphosilicate glass. The glass material may include alkali-containing glass or alkali-free glass, any of which may be free of lithium oxide or contain lithium oxide. In various aspects, the glass material may be alkali-free, and / or include a low content of alkali metals (e.g., about 10 molar percent or less of R 2 O, where R 2 O includes Li 2 O、Na 2 O or K 2 O).

[0172] As used herein, "ceramic" refers to a crystalline phase. A ceramic sheet includes one or more crystalline phases that together account for at least 50 weight percent of the ceramic sheet. The ceramic material can be strengthened (e.g., chemically strengthened). In various aspects, the ceramic material can be formed by heating a substrate including a glass material to form a ceramic (e.g., crystalline) portion. In various aspects, the ceramic material can include one or more nucleating agents that can promote the formation of a crystalline phase. The ceramic material can include one or more oxides, nitrides, oxynitrides, carbides, and / or silicides.

[0173] The haze used herein refers to the transmitted haze measured through the light extraction device (from the first major surface 127 to the second major surface 135) at 0° relative to the normal direction of the second major surface 135 according to the ASTM D1003-21 standard. The haze is measured using a HAZE-GARD PLUS available from BYK Gardner, which has a hole on the source port. The diameter of the hole is 8 mm. A CIE C illuminator is used as a light source to illuminate the light extraction device 121. In various aspects, the haze of the light extraction device 121 is about 2% or less, about 1.5% or less, about 1% or less, or about 0.5% or less.

[0174] like Figure 1-2As shown, the display device 101 and 201 includes a backlight device 102 and 202, and the backlight device includes a light emitting surface 110. The backlight is configured to emit light to a light extraction device 121 through the light emitting surface 110. The first main surface 127 of the first sheet 123 of the light extraction device 121 is arranged on and / or in contact with the light emitting surface 110 of the backlight device 102 and 202. The backlight device 102 and 202 includes a plurality of light sources 107, which are arranged on the main surface 105 of the optical substrate 103. For example, the plurality of light sources 107 may include light sources 108a-108c that may be arranged in a row. Although not shown, the plurality of light sources may be further arranged in a two-dimensional array. The light sources 108a-108c may include inorganic light emitting diodes (LEDs), organic LEDs (OLEDs) and / or lasers. In various aspects, the light sources 108a-108c can be configured to emit "blue" light having a wavelength in the range of about 400 nanometers to about 500 nanometers, about 420 nanometers to about 480 nanometers, about 450 nanometers to about 470 nanometers, or any range or sub-range therebetween. The light sources 108a-108c can be controlled to turn on / off and / or modulate intensity so that the backlight devices 102 and 202 produce a predetermined brightness and / or image.

[0175] like Figure 1-2 As shown, display devices 101 and 201 include a color converter 104, which includes a plurality of pixels 106. One pixel in the plurality of pixels 106 may include three sub-pixels 114a-114c. Figure 1-2 1 is a single pixel including three sub-pixels 114a-114c, but it is understood that other pixels may be substantially the same and / or identical to the pixel shown. Each sub-pixel 114a-114c is defined by a plurality of walls 111a-111d. Fig. 9 As shown, the plurality of walls 111a-111d may include a network of interconnected walls. The walls may include absorbing materials and / or reflective materials to prevent light in one sub-pixel from entering an adjacent sub-pixel and / or an adjacent pixel. Figure 1-2 As shown, the plurality of pixels 106 are positioned between the plurality of light sources 107 and the light emitting surface 110 of the backlight 102. Further, one or more light sources 108a-c may be aligned with corresponding sub-pixels of the plurality of pixels 106.

[0176] like Figure 1-2As shown, sub-pixels 114a-114c may include phosphor material layers 115a-115c. As used herein, a "photoluminescent" material refers to a material that can emit light of a second wavelength (such as visible light) when light of a first wavelength is absorbed by the material, wherein the first wavelength and the second wavelength are different. In various aspects, the phosphor material layers 115a-115c may include quantum dots or conventional phosphors, which may be dispersed in an optically transparent polymer material. Providing quantum dots may increase the color gamut by emitting light in a narrower range of light wavelengths than conventional phosphors. The phosphorescence thickness 116 is defined as the average thickness of the phosphorescent material layers 115a-115c, which may be about 3 microns or more, about 5 microns or more, about 10 microns or less, or about 8 microns or less, for example, about 3 microns to about 10 microns, about 5 microns to about 8 microns, or any range or sub-range therebetween. In addition, providing quantum dots may reduce the phosphorescence thickness while converting substantially all light incident on the phosphorescent material layer from multiple light sources into another light wavelength. In various aspects, one of the phosphor material layers may not convert incident light to another wavelength of light (e.g., a "blue" sub-pixel may pass "blue" light from multiple light sources), while other phosphor material layers may convert incident light to different wavelengths of light (e.g., a "red" sub-pixel and / or a "green" sub-pixel). Phosphor material layers 115a-115c may include a surface facing the multiple light sources 107, and the surface may extend in a common plane with the fourth major surface 112a-112d of the multiple walls 111a-111d, while in other aspects, the surface may be recessed from the fourth major surface 112a-112d.

[0177] like Figure 1-2As shown, sub-pixels 114a-114c may include absorptive color filters 117a-117c. The absorptive color filters may include one or more dyes (such as inks, pigments), which may be optionally dispersed in a polymer material. The one or more dyes may be configured to absorb one or more light wavelength ranges that are different from the light wavelengths that the corresponding phosphorescent material layer is configured to emit and / or transmit. For example, if the photoluminescent material layer 115b converts incident "blue" light into "green" light (which, for example, includes a light wavelength of about 500 nanometers to about 580 nanometers), then the corresponding absorptive color filter 117b may be configured to absorb light other than "green" light (e.g., all visible light) (e.g., absorbing light wavelengths of about 300 nanometers to about 500 nanometers and about 580 nanometers to about 800 nanometers). The filter thickness 118 is defined as the average thickness of the absorptive color filters 117a-117c, and can be about 1 micron or more, about 3 microns or more, about 10 microns or less, or about 5 microns or less, for example, in the range of about 1 micron to about 10 microns, about 3 microns to about 5 microns, or any range or sub-range therebetween. The absorptive color filters 117a-117c can include a second major surface 119a-119c, which can extend in a common plane with the third major surface 113a-113d of the plurality of walls 111a-111d, however in other aspects, the second major surface 119a-119c can be recessed from the third major surface 113a-113d.

[0178] like Figure 1-2 As shown, the sub-pixel thickness 109 is defined as the average distance between the fourth major surface 112a-112d of the plurality of walls 111a-111d and the third major surface 113a-113d of the plurality of walls 111a-111d. The sub-pixel thickness 109 can be about 8 microns or more, about 10 microns or more, about 15 microns or more, about 30 microns or less, about 25 microns or less, or about 20 microns or less. For example, the sub-pixel thickness 109 can range from about 8 microns to about 30 microns, about 10 microns to about 25 microns, about 15 microns to about 20 microns, or any range or sub-range therebetween.

[0179] In various aspects, such as Figure 2As shown, the backlight device 202 may include a dichroic mirror 203 positioned between the multiple light sources 107 and the phosphorescent material layers 115a-115c. The dichroic mirror used herein is configured to allow light having a certain range of light wavelengths to pass through in at least one direction, while reflecting light outside the light wavelength range in at least another direction. For example, the dichroic mirror 203 can be configured to allow light (such as "blue" light) emitted from the multiple light sources 107 to be transmitted through the dichroic mirror 203, while reflecting light (such as "red" light and / or "green" light) emitted from the photoluminescent material layers 115b-115c. The dichroic mirror includes a fifth major surface 205 facing and / or contacting the multiple walls 111a-111d and a sixth major surface 207 opposite to the fifth major surface 205. The sixth major surface 207 can face the multiple light sources 107. Providing a dichroic mirror can increase the brightness of the backlight device, for example, by reflecting light emitted from the phosphorescent material layer and incident on the dichroic mirror. Alternatively, in various aspects, as Figure 1 As shown, backlight device 102 may not include a dichroic mirror.

[0180] In various aspects, such as Figure 2 As shown, the backlight device 202 may include a polarizer 213, which is positioned between the absorptive color filters 117a-117c and the first sheet 123 of the light extraction device 121. The polarizer used in this article allows light of a given polarization (such as circular polarization, vertical polarization, horizontal polarization) to pass. Providing a polarizer can increase contrast and / or reduce glare, for example, by reducing ambient light entering the sub-pixel so that it is not transmitted to the observer. The polarizer 213 includes a seventh major surface 215 and an eighth major surface 217, and the seventh major surface can face, be attached to and / or contact the first major surface 127 of the first sheet 123, and the eighth major surface is opposite to the seventh major surface 215. The eighth major surface 217 of the polarizer 213 can face, be attached to and / or contact the multiple walls 111a-111d of the color converter 104. In other aspects, the seventh major surface 215 of the polarizer 213 can include the light emitting surface 110 of the backlight device 202. Alternatively, as Figure 1 As shown, backlight 102 may be devoid of polarizers and light emitting surface 110 may include one or more of third major surfaces 113a-113d of plurality of walls 111a-111d or second major surfaces 119a-119c of absorptive color filters 117a-117c.

[0181] like Fig. 9As shown, one pixel in the plurality of pixels 106 includes a length 901 and a width 903. In various aspects, the first sub-pixel 114a includes a first sub-pixel length 911a and / or a first sub-pixel width 913a, and the first sub-pixel length and / or the first sub-pixel width can be smaller than the corresponding sub-pixel length 911b and / or 911c and / or the corresponding sub-pixel width 913b and / or 913c of the second sub-pixel 114b and / or the third sub-pixel 114c. For example, the first sub-pixel 114a can be configured to transmit light from the plurality of light sources 107 (see Figure 1-2 ) emits "blue" light, if the size (e.g., length and / or width) of the first sub-pixel 114a is the same as the size of the second sub-pixel 114b and / or the third sub-pixel 114c, then due to the absorptive color filter layers 117b-117c (see Figure 1-2 ) in the absorptive color filters 117a-117c of the three sub-pixels 114a-114c, the light may be perceived as brighter than the other sub-pixels 114b-114c. In various aspects, the second sub-pixel 114b and the third sub-pixel 114c may include a sub-pixel length 911b or 911c and / or a sub-pixel width 913b or 913c of the same value. For example, one or more sub-pixels may include a corresponding sub-pixel length 911a-911c, which is substantially equal to the corresponding sub-pixel width 913a-913c. The area of ​​the pixel light emitting surface 110 corresponding to the second main surfaces 119a-119c of the absorptive color filters 117a-117c of the three sub-pixels 114a-114c may be approximately 66% or less, approximately 50% or less, approximately 40% or less, approximately 33% or less, or approximately 25% or less of the total area of ​​the pixel light emitting surface 110. Providing a low percentage (e.g., about 66% or less, about 50% or less, about 40% or less, about 33% or less, about 25% or less) of the pixel area occupied by sub-pixels can allow for omission of dichroic mirrors and / or polarizers without increasing glare, reducing contrast, or reducing brightness beyond a predetermined threshold of corresponding values.

[0182] In a first set of embodiments, the first sheet 123 may include a plurality of pyramid structures 122, the plurality of pyramid structures including a base angle 401, and a first refractive index of about 1.6 or greater. In various aspects, the first refractive index may be about 1.65 or greater, about 1.67 or greater, about 1.7 or greater, about 1.72 or greater, about 1.75 or greater, about 1.9 or less, about 1.88 or less, about 1.85 or less, or about 1.8 or less. For example, the first refractive index of the first sheet may range from about 1.65 to about 1.9, about 1.67 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.9, about 1.75 to about 1.9, about 1.75 to about 1.88, about 1.75 to about 1.85, about 1.75 to about 1.8, or any range or sub-range therebetween. In addition, the second refractive index can be about 1.4 or greater, about 1.45 or greater, about 1.48 or greater, about 1.6 or less, about 1.55 or less, or about 1.53 or less. For example, the second refractive index can range from about 1.4 to about 1.6, about 1.45 to about 1.55, about 1.48 to about 1.53, or any range or sub-range therebetween. Providing a first refractive index of about 1.6 or greater (e.g., about 1.65 or greater, about 1.7 or greater, or about 1.75 or greater) can increase the brightness of light extracted from the light extraction device, for example, by reducing total internal reflection (TIR) ​​of light to be coupled into the light extraction device. Providing a first refractive index of about 1.9 or less (e.g., about 1.88 or less, about 1.85 or less, about 1.8 or less) can increase the brightness of light extracted from the light extraction device, for example, by reducing light lost due to Fresnel reflection at the first major surface (e.g., light to be coupled into the first refractive index) and / or the second patterned surface 125 (e.g., light to be coupled out of the first sheet). As discussed with respect to the examples below, providing a first refractive index within one or more of the above ranges can provide an unexpected benefit of increasing the brightness of light extracted from a light extraction device (e.g., a light extraction device, a display device).

[0183] The bottom angle 401 can be about 50° or greater, about 55° or greater, about 60° or greater, about 62° or greater, about 65° or greater, about 80° or less, about 78° or less, about 75° or less, about 72° or less, or about 70° or less. For example, the bottom angle 401 can range from about 50° to about 80°, about 55° to about 80°, about 60° to about 80°, about 60° to about 78°, about 60° to about 75°, about 62° to about 75°, about 65° to about 75°, about 65° to about 72°, about 65° to about 70°, or any range or sub-range therebetween. Providing a bottom angle of about 60° or greater (e.g., about 65° or greater, about 70° or greater, about 75° or greater) can increase the brightness of light extracted from the light extraction device, for example by reducing TIR. As discussed with respect to the examples below, providing a base angle within one or more of the above ranges can provide the unexpected benefit of increasing the brightness of light extracted from a light extraction device (eg, a light extraction apparatus, a display device).

[0184] In various aspects, the pyramid structure 126a (or multiple pyramid structures 122) may include a quadrangular pyramid 603 whose base angle 401 ranges from about 60° to about 80°, about 60° to about 75°, about 62° to about 75°, about 65° to about 75°, about 65° to about 75°, about 65° to about 72°, or about 65° to about 70°, and / or the first refractive index of the first sheet 123 may range from about 1.7 to about 1.9, about 1.72 to about 1.85, or about 1.75 to about 1.85. In various aspects, the pyramid structure 126a (or multiple pyramid structures 122) may include a triangular pyramid 703 whose base angle 401 ranges from about 50° to about 80°, about 50° to about 75°, about 50° to about 70°, about 50° to about 65°, about 50° to about 60°, or about 50° to about 58°, and / or the first refractive index of the first sheet 123 may range from about 1.65 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.9, or about 1.75 to about 1.9. In various aspects, the pyramid structure 126a (or multiple pyramid structures 122) may include a hexagonal pyramid 803 whose base angle 401 ranges from about 60° to about 80°, about 60° to about 78°, about 60° to about 75°, about 60° to about 72°, or about 60° to about 70°, and / or the first refractive index of the first sheet 123 may range from about 1.65 to about 1.9, about 1.67 to about 1.9, about 1.7 to about 1.9, about 1.7 to about 1.88, or about 1.68 to about 1.88.

[0185] In a second set of embodiments, the second sheet 133 may include a plurality of pyramid structures 152, the plurality of pyramid structures including a base angle 409, and a first refractive index of about 1.6 or greater. In various aspects, the second refractive index may be about 1.65 or greater, about 1.67 or greater, about 1.7 or greater, about 1.72 or greater, about 1.75 or greater, about 1.9 or less, about 1.88 or less, about 1.85 or less, or about 1.8 or less. For example, the second refractive index of the second sheet may range from about 1.65 to about 1.9, about 1.67 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.9, about 1.75 to about 1.9, about 1.75 to about 1.88, about 1.75 to about 1.85, about 1.75 to about 1.8, or any range or sub-range therebetween. In other aspects, the first refractive index can be about 1.4 or greater, about 1.45 or greater, about 1.48 or greater, about 1.6 or less, about 1.55 or less, or about 1.53 or less. For example, the first refractive index can range from about 1.4 to about 1.6, about 1.45 to about 1.55, about 1.48 to about 1.53, or any range or sub-range therebetween. As discussed with respect to the examples below, providing a first refractive index within one or more of the above ranges can provide an unexpected benefit of increasing the brightness of light extracted from a light extraction device (e.g., a light extraction device, a display device).

[0186] The bottom angle 409 can be about 50° or greater, about 55° or greater, about 60° or greater, about 62° or greater, about 65° or greater, about 80° or less, about 78° or less, about 75° or less, about 72° or less, or about 70° or less. For example, the bottom angle 409 can range from about 50° to about 80°, about 55° to about 75°, about 60° to about 75°, about 65° to about 75°, about 70° to about 75°, or any range or sub-range therebetween. As discussed with respect to the examples below, providing a bottom angle within one or more of the above ranges can provide an unexpected benefit of increasing the brightness of light extracted from a light extraction device (e.g., a light extraction device, a display device).

[0187] In various aspects, the pyramid structure 156a (or multiple pyramid structures 122) may include a quadrangular pyramid 603 whose base angle 409 ranges from about 60° to about 80°, about 60° to about 75°, about 62° to about 75°, about 65° to about 75°, about 68° to about 75°, or about 70° to about 75°, and / or the second refractive index of the second sheet 133 may range from about 1.7 to about 1.9, about 1.72 to about 1.9, about 1.75 to about 1.9, or about 1.75 to about 1.85. In various aspects, the pyramid structure 156a (or multiple pyramid structures 152) may include a triangular pyramid 703 whose base angle 409 ranges from about 50° to about 80°, about 50° to about 75°, about 50° to about 70°, about 55° to about 70°, about 57° to about 68°, or about 60° to about 65°, and / or the second refractive index of the second sheet 133 may range from about 1.65 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.9, or about 1.75 to about 1.9. In various aspects, the pyramid structure 156a (or multiple pyramid structures 152) may include a hexagonal pyramid 803 whose base angle 409 ranges from about 60° to about 80°, about 60° to about 78°, about 60° to about 75°, about 60° to about 72°, or about 60° to about 70°, and / or the second refractive index of the second sheet 133 may range from about 1.65 to about 1.9, about 1.67 to about 1.9, about 1.7 to about 1.9, about 1.7 to about 1.88, or about 1.68 to about 1.88.

[0188] Now, the method of making the light extraction device 121 will be discussed. In the first group of methods, the second sheet 133 can be formed and patterned on the fourth major surface 147 of the substrate 143, for example, by imprinting a pattern to form a first patterned surface 137 while curing (e.g., heating, irradiating) a precursor to form the second sheet 133, or by embossing a pattern with a heated second sheet 133 (which, for example, includes a thermoplastic polymer) to form the first patterned surface 137. Then, the first sheet 123 including the second patterned surface 125 can be formed on the first patterned surface 137, and the first sheet 123 includes a first major surface 127 extending along the first plane 126 and opposite to the second patterned surface 125. In various aspects, the first patterned surface 137 may correspond to a negative mold that forms the second patterned surface 125 of the first sheet 123, the second patterned surface comprising a plurality of pyramid structures 122 that include one or more aspects described above within one or more corresponding ranges (e.g., base angle, ratio of height to width of the pyramid structure, ratio of radius of curvature at peak to height of the pyramid structure). Alternatively, the second sheet 133 comprising the first patterned surface 137 may include a plurality of pyramid structures 152 that include one or more aspects described above within one or more corresponding ranges (e.g., base angle, ratio of height to width of the pyramid structure, ratio of radius of curvature at peak to height of the pyramid structure).

[0189] In a second group of methods, a first sheet 123 may be formed on a temporary substrate (not shown), for example, by imprinting a pattern to form a second patterned surface 125 while curing (e.g., heating, irradiating) a precursor to form the first sheet 123, or by embossing a pattern with a heated second sheet 123 (which, for example, includes a thermoplastic polymer) to form the second patterned surface 125. The first sheet 123 may then be transferred to a substrate 143 (e.g., via a roll-to-roll process) and a second sheet 133 may be formed and / or patterned therebetween. Alternatively, a second sheet 133 including a first patterned surface 137 may be formed on the second patterned surface 125, and the second sheet 133 includes a second major surface 135 extending along a second plane 136 and opposite to the first patterned surface 137; then, a light extraction device 121 (e.g., as shown) may be formed by transferring the first sheet 123 and the second sheet 133 to the substrate 143 and removing the temporary substrate. Figure 3As shown). The first sheet 123 including the second patterned surface 125 further includes a plurality of pyramid structures 122, which include one or more aspects described above in one or more corresponding ranges (e.g., base angle, ratio of height to width of the pyramid structure, ratio of radius of curvature at the peak to the height of the pyramid structure). Alternatively, the second patterned surface 125 of the first sheet 123 may correspond to a negative mold, which is used to form the first patterned surface 137 of the second sheet 133 when the first sheet 123 is transferred to the substrate 143, the first patterned surface including a plurality of pyramid structures 152 (which include one or more aspects described above in one or more corresponding ranges (e.g., base angle, ratio of height to width of the pyramid structure, ratio of radius of curvature at the peak to the height of the pyramid structure)).

[0190] Example

[0191] Various aspects will be further illustrated by the following examples. Tables 1-8 and Figure 10-23 All data presented in the table are relative brightness values ​​of the light extraction device measured in a ray tracing simulation using Synopsis LightTools software relative to a planar monolithic material layer with a refractive index of 1.5 and a thickness equal to the thickness of the corresponding light extraction device. Figure 10-17 , assuming that the incident light is transmitted to the first main surface of the first sheet through a material with a refractive index of 1.5, and the refractive index of the second sheet is 1.5, the two brightness values ​​used to determine the relative brightness both correspond to a viewing angle of 0° (i.e., the normal direction relative to the second main surface 135 of the second sheet 133 is 0°). For Tables 5-7 and Figure 18-23 , assuming that the incident light is transmitted through the material with a refractive index of 1.5 to the first major surface of the first sheet with a refractive index of 1.5, and the second sheet is arranged on the first sheet, the two brightness values ​​used to determine the relative brightness both correspond to a viewing angle of 0° (i.e., the normal direction relative to the second major surface 135 of the second sheet 133 is 0°).

[0192] In Table 1-8, relative brightness values ​​of 160% or greater are indicated in bold. Figure 10-16 In FIG. 1 , the horizontal axis 1001 is the viewing angle in degrees, and the vertical axis 1003 is the relative brightness (%). Figure 18-23 , the horizontal axis 1801 is the viewing angle in degrees, and the vertical axis 1803 is the relative brightness (%). Figure 10-16 or Figure 18-23 The curve 1005 or 1805 shown includes a single layer of material having a refractive index of 1.5, the material layer being used as Figure 10-23 Without wishing to be bound by theory, a viewing angle of 0° (ie 0° relative to the normal direction of the second major surface 135 of the second sheet 133) corresponds to the direction of maximum brightness for an observer viewing the light extraction device.

[0193] Table 1 presents the relative brightness of a light extraction device including a tetrahedron, with the leftmost row listing the base angle and / or the aspect ratio (H / W) of the pyramid and the top column listing the refractive index of the first sheet. As described above, the row with the first refractive index of 1.5 is 100% (by definition, because the refractive index of the baseline is 1.5 and the second refractive index is 1.5). As shown in Table 1, when the base angle is 60° or greater, the relative brightness of at least some values ​​is 160% or greater, but when the base angle is less than 60°, no value has a relative brightness of at least 160%, at least 150%, at least 140%, or at least 130%. Therefore, a tetrahedron with a base angle of about 60° or greater has unexpected benefits and qualitative differences relative to other base angles. When the base angles are 65° and 70°, the values ​​with relative brightness values ​​of 160% or greater account for the largest proportion, and the larger the base angle, the smaller this proportion. For example, when the base angle is about 60° to about 80°, about 62° to about 75°, about 65° to about 72°, about 65° to about 70°, or any range or sub-range therebetween, an unexpected benefit of increased relative brightness can be achieved. Further, when the base angle is about 60° to about 65°, a relative brightness value of 190% or greater can be achieved, and when the base angle is about 65°, a relative brightness value of 200% or greater can be achieved. Similarly, when the H / W ratio is 0.9 to about 2.8, 1 to about 1.9, 1.1 to about 1.4, or any range or sub-range therebetween, an unexpected benefit of increased relative brightness can also be achieved.

[0194] As shown in Table 1, when the first refractive index is 1.65 or greater, the relative brightness is 160% or greater (e.g., 170% or greater), and when the first refractive index is less than 1.65, all values ​​are less than 160% (when the first refractive index is less than 1.65, all values ​​except one are less than 150% or 140%). Therefore, relative to other values ​​of the first refractive index, the tetrahedron with a first refractive index of about 1.65 or greater has unexpected benefits and qualitative differences. When the first refractive index is 1.8 and 1.85, the relative brightness value is 160% or greater. For example, when the first refractive index is about 1.65 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.87, about 1.75 to about 1.85, or any range or sub-range therebetween, the unexpected benefit of increased relative brightness can be achieved. In combination with the above observations regarding the base angle and first refractive index of the tetrahedral pyramid, an unexpected benefit of increased relative brightness is achieved at most values ​​of the following conditions, for example: (a) a base angle of about 60° to about 80° and a first refractive index of about 1.65 to about 1.9 (73% value); (b) a base angle of about 60° to about 80° and a first refractive index of about 1.7 to about 1.9 (80% value); (c) a base angle of about 60° to about 75° and a first refractive index of about 1.7 to about 1.9 (85% value); (d) a base angle of about 60° to about 75° and a first refractive index of about 1.75 to about 1.9 (93% value); and / or (e) a base angle of about 65° to about 70° and a first refractive index of about 1.65 to about 1.9 (100% value).

[0195] Table 1: Relative brightness of quadrangular pyramid (%) (refractive index of first sheet)

[0196]

[0197]

[0198] Figure 10-11 The relative brightness of the four-cornered pyramid as a function of viewing angle is presented. Fig.10 In FIG. 1 , all curves correspond to a quadrangular pyramid with a base angle of 65°. Curves 1007, 1009, 1011, 1013, 1015, 1017, and 1019 correspond to first refractive indices of 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, and 1.9, respectively. Fig.10 As shown, when the viewing angle approaches 0°, curve 1007 (the first refractive index is 1.6) decreases slightly. In contrast, when the viewing angle approaches 0°, curves 1009, 1011, 1013, 1015, 1017, and 1019 increase. Fig.10Among the curves shown, curve 1015 (first refractive index is 1.8) has the largest relative brightness, followed by curve 1017 (first refractive index is 1.85), and then curves 1011, 1013 and 1019 (first refractive indices are 1.7, 1.75 and 1.9 respectively), which have roughly the same relative brightness near a viewing angle of 0°.

[0199] exist Fig.11 In FIG. 1 , all curves correspond to a quadrangular pyramid with a first refractive index of 1.8. The base angles of curves 1107, 1109, 1111, and 1113 are 30°, 45°, 65°, and 75°, respectively. When the viewing angle approaches 0°, curves 1107 and 1109 (with base angles of 30° and 45°, respectively) decrease. In contrast, when the viewing angle approaches 0°, curves 1111 and 1113 increase. Fig.11 Among the curves shown, the relative brightness of curve 1111 (base angle 65°) is the highest.

[0200] Table 2 presents the relative brightness of a light extraction device including a triangular pyramid, with the leftmost row listing the base angle and / or the pyramid aspect ratio (H / W), and the top column listing the refractive index of the first sheet. As shown in Table 2, when the base angle is 50° or greater, the relative brightness of at least some values ​​is 160% or greater, but when the base angle is less than 50°, no value has a relative brightness of at least 160%, at least 150%, or at least 145%. Therefore, relative to other base angles, the triangular pyramid with a base angle of about 50° or greater has unexpected benefits and qualitative differences. When the base angles are 50° and 55°, the relative brightness values ​​of 160% or greater account for the largest portion, and the larger the base angle, the smaller this portion. For example, when the base angle is about 50° to about 80°, about 50° to about 75°, about 50° to about 70°, about 50° to about 68°, about 50° to about 65°, about 50° to about 63°, about 50° to about 60°, or any range or sub-range therebetween, an unexpected benefit of increased relative brightness can be achieved. Further, when the base angle is about 55° to about 65°, a relative brightness value of 190% or greater can be achieved, and when the base angle is about 55° to about 65°, a relative brightness value of 200% or greater can be achieved. Similarly, when the H / W ratio is about 0.6 to about 2.8, 0.6 to about 1.9, 0.6 to about 1.4, 0.6 to about 1.1, 0.6 to about 0.9, or any range or sub-range therebetween, an unexpected benefit of increased relative brightness can also be achieved.

[0201] As shown in Table 2, when the first refractive index is 1.65 or greater, the relative brightness is 160% or greater, and when the first refractive index is less than 1.65, all values ​​are less than 160% (when the first refractive index is less than 1.65, all values ​​except one are less than 150%, 140% or 130%). Therefore, relative to other values ​​of the first refractive index, the triangular pyramid with a first refractive index of about 1.65 or greater has unexpected benefits and qualitative differences. When the first refractive index is 1.75 to 1.9, the relative brightness value of 160% or greater accounts for the largest portion. For example, when the first refractive index is about 1.65 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.9, about 1.75 to about 1.9, about 1.75 to about 1.9, about 1.75 to about 1.88, about 1.75 to about 1.85, or any range or sub-range therebetween, the unexpected benefit of increased relative brightness can be achieved. In combination with the above observations regarding the base angle and first refractive index of the triangular pyramid, an unexpected benefit of increased relative brightness is achieved at most values ​​of the following conditions, for example: (a) a base angle of about 50° to about 80° and a first refractive index of about 1.65 to about 1.9 (74% value); (b) a base angle of about 50° to about 80° and a first refractive index of about 1.7 to about 1.9 (83% value); and / or (c) a base angle of about 50° to about 65° and a first refractive index of about 1.7 to about 1.9 (100% value).

[0202] Table 2: Relative brightness of triangular pyramid (%) (refractive index of first sheet)

[0203]

[0204]

[0205] Figure 12-13 The relative brightness of the triangular cone as a function of viewing angle is presented. Fig.12 In FIG. 1 , all curves correspond to a triangular pyramid with a base angle of 60°. Curves 1207, 1209, 1211, 1213, 1215, 1217, and 1219 correspond to first refractive indices of 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, and 1.9, respectively. Fig.12 As shown, when the viewing angle approaches 0°, curve 1207 (the first refractive index is 1.6) decreases slightly. In contrast, when the viewing angle approaches 0°, curves 1211, 1213, 1215, 1217, and 1219 increase. Fig.12 Among the curves shown, curves 1215 and 1217 (with first refractive indices of 1.8 and 1.85, respectively) have the largest relative brightness, and curves 1213 and 1219 (with first refractive indices of 1.75 and 1.9, respectively) have the next largest relative brightness.

[0206] exist Fig.13 In FIG. 1 , all curves correspond to a triangular pyramid with a first refractive index of 1.8. The base angles of curves 1307, 1309, 1311, and 1313 are 40°, 50°, 60°, and 70°, respectively. Curve 1307 (base angle 40°) decreases as the viewing angle approaches 0°. In contrast, curves 1311 and 1313 increase as the viewing angle approaches 0°. Fig.13 Among the curves shown, the relative brightness of curve 1311 (base angle 60°) is the highest.

[0207] Table 3 presents the relative brightness of a light extraction device including a hexagonal pyramid, with the leftmost row listing the base angle and / or the pyramid aspect ratio (H / W), and the top column listing the refractive index of the first sheet. As shown in Table 3, when the base angle is 60° or greater, the relative brightness of at least some values ​​is 160% or greater, but when the base angle is less than 60°, no value has a relative brightness of at least 160%, at least 150%, or at least 140%. Therefore, relative to other base angles, hexagonal pyramids with base angles of about 60° or greater have unexpected benefits and qualitative differences. When the base angles are 65° and 70°, the relative brightness values ​​of 160% or greater account for the largest portion, and the larger the base angle, the smaller this portion. For example, when the base angle is about 60° to about 80°, about 60° to about 75°, about 60° to about 72°, about 60° to about 70°, or any range or sub-range therebetween, the unexpected benefit of increased relative brightness can be achieved. Further, when the base angle is about 60° to about 75°, a relative brightness value of 190% or more can be achieved, and when the base angle is about 70°, a relative brightness value of 200% or more can be achieved. Similarly, when the H / W ratio is about 0.85 to about 2.8, 0.85 to about 1.9, 0.85 to about 1.4, 0.9 to about 1.4, or any range or sub-range therebetween, the unexpected benefit of increased relative brightness can also be achieved.

[0208] As shown in Table 3, when the first refractive index is 1.65 or greater, the relative brightness is 160% or greater, and when the first refractive index is less than 1.65, all values ​​are less than 160% (when the first refractive index is less than 1.65, all values ​​except one are less than 150%, 140% or 130%). Therefore, the hexagonal pyramid with a first refractive index of about 1.65 or greater has unexpected benefits and qualitative differences relative to other values ​​of the first refractive index. When the first refractive index is 1.85 to 1.9, the relative brightness value of 160% or greater accounts for the largest proportion. For example, an unexpected benefit of increased relative brightness can be achieved when the first refractive index is about 1.65 to about 1.9, about 1.68 to about 1.9, about 1.7 to about 1.9, about 1.7 to about 1.88, about 1.72 to about 1.85, about 1.75 to about 1.85, about 1.78 to about 1.85, about 1.8 to about 1.85, or any range or sub-range therebetween. In combination with the above observations regarding the base angle and first refractive index of the hexagonal pyramid, an unexpected benefit of increase is achieved at most values ​​of the following conditions, for example: (a) a base angle of about 60° to about 80° and a first refractive index of about 1.65 to about 1.9 (83% value); (b) a base angle of about 60° to about 75° and a first refractive index of about 1.75 to about 1.9 (90% value); (c) a base angle of about 65° to about 75° and a first refractive index of about 1.7 to about 1.9 (94% value); and / or (d) a base angle of about 60° to about 70° and a first refractive index of about 1.65 to about 1.85 (100% value).

[0209] Table 3: Relative brightness of hexagonal pyramid (%) (refractive index of first sheet)

[0210] Bottom Angle H / W 1.5 1.6 1.65 1.7 1.75 1.8 1.85 1.9 15° 0.13 100 100 100 100 101 101 101 102 20° 0.18 100 100 101 102 102 103 103 104 25° 0.23 100 101 102 102 104 105 106 106 30° 0.29 100 101 102 102 103 103 103 103 35° 0.35 100 101 101 100 101 101 102 103 40° 0.42 100 100 101 101 101 103 106 111 45° 0.50 100 100 101 102 105 113 138 157 50° 0.60 100 101 101 104 113 122 131 132 55° 0.71 100 103 109 127 124 121 118 121 60° 0.87 100 112 161 190 185 175 165 148 65° 1.07 100 151 175 180 195 180 181 167 70° 1.37 100 123 162 199 220 228 230 196 75° 1.87 100 115 134 149 157 166 178 190 80° 2.84 100 111 129 150 162 165 172 179

[0211] Figure 14-15 The relative brightness of the hexagonal cones as a function of viewing angle is presented. Fig.14 In FIG. 1 , all curves correspond to a hexagonal pyramid with a base angle of 70°. Curves 1407, 1409, 1411, 1413, 1415, 1417, and 1419 correspond to first refractive indices of 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, and 1.9, respectively. Fig.14 As shown, when the viewing angle approaches 0°, curve 1407 (the first refractive index is 1.6) decreases slightly. In contrast, when the viewing angle approaches 0°, curves 1409, 1411, 1413, 1415 and 1417 increase. Fig.14Among the curves shown, curves 1415 and 1417 (first refractive indexes are 1.8 and 1.85 respectively) have the largest relative brightness, followed by curve 1413 (first refractive index is 1.75), and then curves 1411 and 1419 (first refractive indexes are 1.7 and 1.9 respectively), whose maximum relative brightness values ​​are approximately the same.

[0212] exist Fig.15 In FIG. 1 , all curves correspond to a hexagonal cone with a first refractive index of 1.8. The base angles of curves 1507, 1509, 1511, and 1513 are 50°, 60°, 70°, and 80°, respectively. Curve 1507 (base angle 50°) decreases as the viewing angle approaches 0°. In contrast, Fig.15 Of the curves shown, curve 1511 (base angle 70°) has the maximum relative brightness. Curves 1509 and 1513 (base angles 60° and 80°, respectively) include relatively flat curves, indicating that these values ​​may represent the end points of a range in which the maximum relative brightness increases from -30° and 30° viewing angles to a local maximum (and global maximum) relative brightness at 0° viewing angle.

[0213] Table 4 and Fig.17 The relative brightness of the light extraction device as a function of the radius of curvature at the peak as a percentage of the cone height (R / H%) is presented. Fig.17 In the embodiment, the plurality of pyramid structures include a quadrangular pyramid with a base angle of 65° and a first refractive index of 1.8. Fig.17 , the horizontal axis 1701 corresponds to the ratio of the radius of curvature at the peak to the cone height, and the vertical axis 1703 corresponds to the relative brightness at a viewing angle of 0°. As shown, the curve 1705 corresponding to the relative brightness initially decreases gradually, and then decreases at a faster rate when the R / H% value is higher. For example, when R / H% is about 20% or less, the relative brightness differs from the maximum value (at R / H% = 0) by less than 6%, while when R / H% is 25% or greater, the relative brightness drops to a difference of more than 10% from the maximum value. Therefore, when R / H% is about 20% or less, the trend of relative brightness is a gradual decrease, which is qualitatively different from the sharp decrease in relative brightness when R / H% is greater than 20% (such as 25% or greater).

[0214] Table 4: Relative brightness at the radius of curvature at the peak of the pyramid

[0215]

[0216]

[0217] Fig.16The relative brightness of a quadrangular pyramid with a base angle of 65° and a first refractive index of 1.8 as a function of viewing angle is presented. Curves 1607, 1609, 1611, 1613, 1615 and 1617 correspond to R / H% of 0%, 10%, 20%, 30%, 40% and 50%, respectively. Figure 4 As shown, curve 1607 is the same as curve 1011 corresponding to the peak. Curve 1617 (R / H% = 50%) corresponds to a hemispherical structure rather than a pyramid structure. As shown in the figure, the relative brightness decreases as the R / H% increases. Curves 1607 and 1609 (R / H% is 0% and 10% respectively) have the highest relative brightness values, followed by curve 1611 (R / H% is 20%). When the viewing angle approaches 0°, curves 1613 and 1615 increase, but the relative brightness values ​​of curves 1613 and 1615 are less than curves 1607, 1609 and 1611. When the viewing angle approaches 0°, curve 1617 does not increase significantly.

[0218] Table 5 presents the relative brightness of a light extraction device including a tetrahedron, with the leftmost row listing the base angle and / or the pyramid aspect ratio (H / W), and the top column listing the refractive index of the first sheet. Unlike Table 1, the refractive index in the first column corresponds to the second refractive index of the second sheet, not the first refractive index of the first sheet. As described above, the row with a first refractive index of 1.5 is 100% (by definition, because the refractive index of the baseline is 1.5 and the second refractive index is 1.5). As shown in Table 5, when the base angle is 55° or greater, the relative brightness of at least some values ​​is 160% or greater, but when the base angle is less than 50°, no value has a relative brightness of at least 160%, at least 150%, at least 140%, at least 130%, at least 120% or at least 110%. When the base angle is 55° or less, only one value is greater than 160% (i.e., 164%). Therefore, a four-cornered pyramid with a base angle of about 60° or greater has unexpected benefits and qualitative differences relative to other base angles. The fraction of relative brightness values ​​of 160% or greater is greatest at base angles of 70° and 75°. For example, unexpected benefits of increased relative brightness can be achieved when the base angle is about 60° to about 80°, about 65° to about 78°, about 68° to about 75°, about 70° to about 75°, or any range or sub-range therebetween. Further, when the base angle is about 60° to about 70°, a relative brightness value of 190% or greater can be achieved; when the base angle is about 60° to about 70°, a relative brightness value of 200% or greater (e.g., 210% or greater, 220% or greater, or 230% or greater) can be achieved; and when the base angle is about 60° to about 65°, a relative brightness value of 240% or greater, 250% or greater, 260% or greater, or 270% or greater can be achieved. Similarly, when the H / W ratio is 0.85 to about 2.8, 0.9 to about 1.9, 1 to about 1.4, or any range or sub-range therebetween, the unexpected benefit of increased relative brightness can also be achieved. Compared to Table 1 (the first refractive index is greater than the second refractive index), the maximum value of Table 5 (the second refractive index is greater than the first refractive index) is greater (e.g., about 230% or greater), and there are more values ​​of about 160% or greater.

[0219] As shown in Table 5, when the second refractive index is 1.6 or greater, the relative brightness is 160% or greater (e.g., 170% or greater), and when the second refractive index is less than 1.6, all values ​​are less than 160%. When the second refractive index is 1.65 or greater, the relative brightness is 200% or greater, and when the second refractive index is less than 1.65, all values ​​are less than 200%. Therefore, relative to other values ​​of the second refractive index, the tetrahedron with a second refractive index of about 1.65 or greater has unexpected benefits and qualitative differences. When the second refractive index is 1.9, the relative brightness values ​​of 160% or greater account for the largest proportion, followed by 1.75 to 1.85. For example, unexpected benefits of increased relative brightness can be achieved when the second refractive index is about 1.6 to about 1.9, about 1.65 to about 1.9, about 1.68 to about 1.87, about 1.7 to about 1.85, about 1.72 to about 1.85, about 1.75 to about 1.85, or any range or sub-range therebetween. In combination with the above observations regarding the base angle and the second refractive index of the tetrahedral pyramid, an unexpected benefit of increased relative brightness is achieved at most values ​​of the following conditions, for example: (a) a base angle of about 60° to about 80° and a second refractive index of about 1.65 to about 1.9 (90% value); (b) a base angle of about 60° to about 80° and a second refractive index of about 1.7 to about 1.9 (80% value); (c) a base angle of about 60° to about 75° and a second refractive index of about 1.7 to about 1.9 (85% value); (d) a base angle of about 60° to about 75° and a second refractive index of about 1.75 to about 1.9 (96% value); and / or (e) a base angle of about 65° to about 75° and a second refractive index of about 1.65 to about 1.9 (100% value).

[0220] Table 5: Relative brightness of quadrangular pyramid (%) (refractive index of the second sheet)

[0221] Bottom Angle H / W 1.5 1.6 1.65 1.7 1.75 1.8 1.85 1.9 15° 0.13 100 100 100 100 101 101 101 102 20° 0.18 100 100 101 101 102 103 103 104 25° 0.23 100 101 101 102 102 103 103 103 30° 0.29 100 100 101 101 101 102 103 103 35° 0.35 100 100 101 101 102 102 103 104 40° 0.42 100 100 100 100 101 101 102 103 45° 0.50 100 100 100 100 101 101 100 100 50° 0.60 100 100 101 102 104 105 105 98 55° 0.71 100 102 106 112 124 143 157 164 60° 0.87 100 109 124 185 262 298 299 300 65° 1.07 100 125 213 272 265 254 246 236 70° 1.37 100 186 240 233 223 209 195 189 75° 1.87 100 171 174 176 176 172 168 166 80° 2.84 100 112 120 147 179 184 178 174

[0222] Figure 18-19 The relative brightness of the four-cornered pyramid as a function of viewing angle is presented. Fig.18 In FIG. 1 , all curves correspond to a quadrangular pyramid with a base angle of 65°. Curves 1807, 1809, 1811, 1813, 1815, 1817, and 1819 correspond to second refractive indices of 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, and 1.9, respectively. Fig.18 As shown, when the viewing angle approaches 0°, curves 1809 and 1811 (the second refractive index is 1.65 and 1.7, respectively) decrease slightly. In contrast, when the viewing angle approaches 0°, curves 1815, 1817, and 1819 increase. Curves 1817 and 1819 (the second refractive index is 1.85 and 1.90, respectively) include approximately the same relative brightness, which is Fig.18The curve shown has the greatest relative brightness, followed by curve 1815 (second refractive index is 1.8).

[0223] exist Fig.19 In FIG. 1 , all curves correspond to a quadrangular pyramid with a second refractive index of 1.8. The base angles of curves 1907, 1909, 1911, and 1913 are 40°, 50°, 60°, and 70°, respectively. Curve 1909 (base angle 50°) decreases as the viewing angle approaches 0°. In contrast, curve 1911 (base angle 60°) increases as the viewing angle approaches 0°, and includes Fig.19 The maximum relative brightness in the curve shown.

[0224] Table 6 presents the relative brightness of a light extraction device including a triangular pyramid, with the leftmost row listing the base angle and / or the pyramid aspect ratio (H / W), and the top column listing the refractive index of the second sheet. Unlike Table 2, the refractive index in the second column corresponds to the second refractive index of the second sheet, not the second refractive index of the second sheet. As shown in Table 6, when the base angle is 45° or greater, the relative brightness of at least some values ​​is 160% or greater, but when the base angle is less than 45°, no value has a relative brightness of at least 160%, at least 150%, or at least 145%. Therefore, relative to other base angles, the triangular pyramid with a base angle of about 45° or greater has unexpected benefits and qualitative differences. When the base angle is 60°, the relative brightness value of 160% or greater accounts for the largest portion. For example, when the base angle is about 50° to about 75°, about 52° to about 72°, about 55° to about 70°, or any range or sub-range therebetween, the unexpected benefit of increased relative brightness can be achieved. Further, when the base angle is about 45° to about 70°, a relative brightness value of 190% or more (e.g., about 200% or more, about 210% or more, about 220% or more) can be achieved; when the base angle is about 50° to about 60°, a relative brightness value of 230% or more can be achieved; and when the base angle is 60°, a relative brightness value of 240% or more (e.g., 250% or more, 260% or more, 270% or more, 280% or more) can be achieved. Similarly, when the H / W ratio is about 0.5 to about 2.8, about 0.5 to about 1.9, about 0.5 to about 1.4, about 0.6 to about 1.1, about 0.7 to about 0.9, or any range or sub-range therebetween, the unexpected benefit of increased relative brightness can also be achieved. Compared with Table 2 (first refractive index greater than second refractive index), Table 6 (second refractive index greater than first refractive index) has a larger maximum value (eg, about 220% or greater), and more values ​​of about 160% or greater.

[0225] As shown in Table 6, when the second refractive index is 1.6 or greater, the relative brightness is 160% or greater, and when the second refractive index is less than 1.6, all values ​​are less than 160% (when the second refractive index is less than 1.6, all values ​​except one are less than 150%, 140%, 130%, 120% or 110%). When the refractive index is less than 1.65, only one value is greater than 160% (i.e., 183%). Therefore, relative to other values ​​of the second refractive index, the triangular pyramid with a second refractive index of about 1.65 or greater has unexpected benefits and qualitative differences. When the second refractive index is 1.75 to 1.85, the relative brightness value is 160% or greater. The value accounts for the largest portion. For example, when the second refractive index is about 1.65 to about 1.9, about 1.7 to about 1.9, about 1.72 to about 1.88, about 1.75 to about 1.85, or any range or sub-range therebetween, the unexpected benefit of increased relative brightness can be achieved. In combination with the above observations regarding the base angle and second refractive index of the triangular pyramid, an unexpected benefit of increased relative brightness is achieved at most values ​​of the following conditions, for example: (a) a base angle of about 50° to about 80° and a second refractive index of about 1.65 to about 1.9 (83% value); and / or (b) a base angle of about 50° to about 70° and a second refractive index of about 1.7 to about 1.85 (100% value).

[0226] Table 6: Relative brightness of triangular pyramid (%) (refractive index of the second sheet)

[0227] Bottom Angle H / W 1.5 1.6 1.65 1.7 1.75 1.8 1.85 1.9 15° 0.13 100 101 101 101 102 103 103 103 20° 0.18 100 101 101 101 101 101 102 102 25° 0.23 100 100 100 101 101 102 102 103 30° 0.29 100 100 100 100 101 101 101 102 35° 0.35 100 100 100 101 101 102 102 106 40° 0.42 100 102 105 108 106 101 90 65 45° 0.50 100 104 110 126 174 268 257 118 50° 0.60 100 109 128 176 216 233 221 171 55° 0.71 100 124 197 234 217 193 173 133 60° 0.87 100 183 246 239 235 252 283 291 65° 1.07 100 144 187 219 223 223 219 213 70° 1.37 100 127 178 214 206 189 178 170 75° 1.87 100 128 152 156 162 170 178 183 80° 2.84 100 107 111 126 149 163 165 160

[0228] Figure 20-21 The relative brightness of the triangular cone as a function of viewing angle is presented. Fig. 20 In FIG. 1 , all curves correspond to a triangular pyramid with a base angle of 60°. Curves 2007, 2009, 2011, 2013, 2015, 2017, and 2019 correspond to second refractive indices of 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, and 1.9, respectively. Fig. 20 As shown, when the viewing angle approaches 0°, curves 2007, 2009, 2017 and 2019 increase. Fig. 20 Among the curves shown, curve 2019 (the second refractive index is 1.9) has the largest relative brightness, and curve 2017 (the second refractive index is 1.85) has the second largest relative brightness.

[0229] exist Fig.21In FIG. 1 , all curves correspond to a triangular pyramid with a second refractive index of 1.8. The base angles of curves 2107, 2109, 2111, and 2113 are 40°, 50°, 60°, and 70°, respectively. Curve 2107 (base angle of 40°) decreases to a value less than 100% when the viewing angle approaches 0°. In contrast, curves 2109 and 2111 increase when the viewing angle approaches 0°. Fig.21 Among the curves shown, the relative brightness of curve 2111 (base angle 60°) is the largest.

[0230] Table 7 presents the relative brightness of a light extraction device including hexagonal pyramids, with the leftmost row listing the base angle and / or the pyramid aspect ratio (H / W) and the top column listing the refractive index of the second sheet. Unlike Table 3, the refractive index in the first column corresponds to the second refractive index of the second sheet, rather than the first refractive index of the first sheet. As shown in Table 7, when the base angle is 55° or greater, the relative brightness of at least some values ​​is 160% or greater, but when the base angle is less than 55°, no value has a relative brightness of at least 160%, at least 150%, at least 140%, at least 130%, or at least 120%. Therefore, hexagonal pyramids with base angles of about 55° or greater or about 60° or greater have unexpected benefits and qualitative differences relative to other base angles. When the base angle is 70°, the value with a relative brightness of 160% or greater accounts for the largest portion, followed by 60° to 65°. For example, when the base angle is about 60° to about 80°, about 60° to about 75°, about 60° to about 72°, about 60° to about 70°, or any range or sub-range therebetween, an unexpected benefit of increased relative brightness can be achieved. Further, when the base angle is about 60° to about 75°, a relative brightness value of 190% or greater (e.g., 200% or greater, 210% or greater) can be achieved; when the base angle is 65° to 70°, a relative brightness value of 220% or greater or 230% or greater can be achieved; and when the base angle is 70°, a relative brightness value of 240% or greater can be achieved. Similarly, when the H / W ratio is 0.85 to about 2.8, 0.85 to about 1.9, 0.9 to about 1.4, or any range or sub-range therebetween, an unexpected benefit of increased relative brightness can also be achieved. Compared to Table 3 (the first refractive index is greater than the second refractive index), the maximum value of Table 7 (the second refractive index is greater than the first refractive index) is greater (eg, greater than 230%), and there are more values ​​of about 160% or greater.

[0231] As shown in Table 7, when the second refractive index is 1.6 or greater, the relative brightness is 160% or greater, and when the second refractive index is less than 1.6, all values ​​are less than 160%. When the refractive index is less than 1.65, only one value is greater than 160% (i.e., 186%). Therefore, relative to other values ​​of the second refractive index, the hexagonal pyramid with a second refractive index of about 1.65 or greater has unexpected benefits and qualitative differences. When the second refractive index is 1.85 to 1.9, the relative brightness value is 160% or greater. The portion of values ​​​​occupies the largest proportion. For example, when the second refractive index is about 1.65 to about 1.9, about 1.68 to about 1.88, about 1.7 to about 1.85, about 1.72 to about 1.85, about 1.75 to about 1.85, about 1.8 to about 1.85, or any range or sub-range therebetween, the unexpected benefit of increased relative brightness can be achieved. In combination with the above observations regarding the base angle and second refractive index of the hexagonal pyramid, an unexpected benefit of increased relative brightness is achieved at most values ​​of the following conditions, for example: (a) a base angle of about 60° to about 80° and a second refractive index of about 1.65 to about 1.9 (83% value); (b) a base angle of about 60° to about 75° and a second refractive index of about 1.65 to about 1.9 (92% value); (c) a base angle of about 60° to about 80° and a second refractive index of about 1.75 to about 1.85 (100% value); and / or (d) a base angle of about 60° to about 75° and a second refractive index of about 1.7 to about 1.85 (100% value).

[0232] Table 7: Relative brightness of hexagonal pyramid (%) (refractive index of the second sheet)

[0233] Bottom Angle H / W 1.5 1.6 1.65 1.7 1.75 1.8 1.85 1.9 15° 0.13 100 100 100 100 101 101 101 102 20° 0.18 100 100 101 102 102 103 103 104 25° 0.23 100 101 102 102 103 103 103 103 30° 0.29 100 101 101 101 102 103 104 104 35° 0.35 100 101 101 101 102 103 104 104 40° 0.42 100 101 101 101 102 102 103 103 45° 0.50 100 101 101 102 102 102 103 109 50° 0.60 100 101 102 103 105 105 108 104 55° 0.71 100 103 109 117 131 171 180 143 60° 0.87 100 108 122 160 203 225 215 198 65° 1.07 100 125 197 232 216 196 178 158 70° 1.37 100 186 246 240 234 232 242 251 75° 1.87 100 123 142 177 184 181 186 202 80° 2.84 100 126 142 158 182 196 187 180

[0234] Figure 22-23 The relative brightness of the hexagonal cones as a function of viewing angle is presented. Fig. 22 In FIG. 1 , all curves correspond to a hexagonal pyramid with a base angle of 70°. Curves 2207, 2209, 2211, 2213, 2215, 2217, and 2219 correspond to second refractive indices of 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, and 1.9, respectively. Fig. 22 As shown, when the viewing angle approaches 0°, curves 2207, 2209, 2211, 2213, 2215, 2217 and 2219 increase. Fig. 22 Among the curves shown, curve 2219 (second refractive index is 1.9) has the largest relative brightness, followed by curve 2209 (second refractive index is 1.65), and then curves 2211 and 2217 (second refractive indices are 1.7 and 1.85 respectively), whose maximum relative brightness values ​​are approximately the same.

[0235] exist Fig.23In FIG. 1 , all curves correspond to a hexagonal cone with a second refractive index of 1.8. The base angles of curves 2307, 2309, 2311, and 2313 are 50°, 60°, 70°, and 80°, respectively. Curve 2307 (base angle 50°) decreases as the viewing angle approaches 0°. In contrast, curves 2309, 2311, and 2313 increase as the viewing angle approaches 0°. Fig.23 Among the curves shown, the relative brightness of curve 2311 (base angle 70°) is the largest.

[0236] Table 8 presents the relative brightness of a light extraction device including a tetrahedron, with the leftmost row listing the base angle and / or the pyramid height-to-width ratio (H / W) (e.g., aspect ratio), and the top column listing the refractive index of the first sheet. In Table 8, the first refractive index of the first sheet is 1.8 and the second refractive index of the second sheet is 1.41, instead of 1.5 in Table 1. As shown in Table 8, when the base angle is 65° or the aspect ratio is 1.07, the relative brightness is 160% or greater. In Table 8, when the base angle is 50° to 75° or the aspect ratio is 0.6 to 1.87, the relative brightness is 140% or greater. Table 8 shows that when the layer with a lower refractive index is less than 1.5 (e.g., about 1.4 to about 1.5, or 1.41), an unexpected benefit of increased brightness can be achieved by appropriately selecting the base angle and / or aspect ratio.

[0237] Table 8: Relative brightness of quadrangular pyramid (%) (refractive index of first sheet) (refractive index of second sheet of 1.41)

[0238] Bottom Angle H / W Relative brightness 15° 0.13 101 20° 0.18 102 25° 0.23 104 30° 0.29 101 35° 0.35 101 40° 0.42 107 45° 0.50 120 50° 0.60 147 55° 0.71 148 60° 0.87 133 65° 1.07 169 70° 1.37 153 75° 1.87 141 80° 2.84 131

[0239] As described above, various aspects of the present disclosure provide a light extraction device or a display device including a light extraction device, the light extraction device including a first sheet having a high refractive index and a plurality of corner cone structures. Providing a high refractive index of about 1.6 or greater (e.g., about 1.65 or greater, about 1.7 or greater, or about 1.75 or greater) can increase the brightness of light extracted from the light extraction device. Providing a high refractive index of about 1.9 or less (e.g., about 1.88 or less, about 1.85 or less, about 1.8 or less) can increase the brightness of light extracted from the light extraction device, for example, by reducing light loss from Fresnel reflection. As discussed with respect to the examples below, a specific range of high refractive indices (and / or the absolute difference between the refractive indices of each sheet) can provide an unexpected benefit of increasing the brightness of light extracted from a light extraction device (e.g., a light extraction device, a display device), which can be further improved for specific corner cone structures (e.g., triangles, squares, hexagons).

[0240] For the first sheet, the plurality of pyramid structures include a base angle, the base angle being defined as the interior angle between the second patterned surface and the first plane along which the first major surface extends; for the second sheet, the plurality of pyramid structures include a base angle, the base angle being defined as the interior angle between the first patterned surface and the second plane along which the second major surface of the second sheet extends. Pyramids having base angles approaching 90° (e.g., about 80° or greater) may be more expensive and / or more difficult to manufacture, and may use more material (e.g., about 50° to about 80°, about 60° to about 80°) than pyramids having smaller base angles. Providing a base angle of about 60° or greater (e.g., about 65° or greater, about 70° or greater, about 75° or greater) can increase the brightness of light extracted from the light extraction device, for example by reducing TIR. As discussed with respect to the examples below, a particular range of base angles (and / or the ratio of the height of the pyramid structure to the width of the pyramid structure) can provide an unexpected benefit of increasing the brightness of light extracted from a light extraction device (e.g., a light extraction device, a display device), which can be further refined for specific pyramid structures (e.g., triangles, squares, hexagons). Further, combining a range of high refractive indices (and / or the absolute value of the difference between the refractive indices) with a range of base angles (and / or the ratio of height to width) can further unexpectedly increase the brightness of light extracted from the light extraction device. Setting the ratio of the radius of curvature to the pyramid height at about 0.20 or less (e.g., about 0.15 or less, about 0.10 or less) can maintain the brightness increase achieved by the above-mentioned first refractive index (and / or the difference between the first refractive index and the second refractive index) within a range of base angles (and / or the ratio of height to width). Providing triangular pyramids, quadrangular pyramids and / or hexagonal pyramids may enable a plurality of pyramids to be close-packed, thereby increasing the density of the pyramids and thus improving the brightness of light extracted from the light extraction device.

[0241] Providing a second sheet disposed on the first sheet can enable multiple spaces between the multiple corner cone structures to be filled, which can reduce light scattering at the second patterned surface, which can result in reduced haze, improved image resolution and / or increased brightness of light extracted from the light extraction device. Setting the absolute value of the difference in refractive index to about 0.4 or less (e.g., about 0.35 or less, about 0.3 or less) can increase the brightness of the light extracted from the light extraction device. Setting the absolute value of the difference in refractive index to about 0.15 or greater (e.g., about 0.20 or less, about 0.25 or greater) can increase the brightness of the light extracted from the light extraction device. Providing a second major surface of the second sheet (which, for example, extends along a second plane) can efficiently extract light from the light extraction device to the substrate (if provided) and simplify the manufacture of the light extraction device.

[0242] In various aspects, the first sheet material may include a high refractive index. The high refractive index of the first sheet material may increase the brightness of light extracted from the light extraction device, for example, by reducing total internal reflection (TIR) ​​of light to be coupled into the light extraction device. Providing a second sheet material having a second refractive index less than the high refractive index may increase the brightness of light extracted from the light extraction device, for example, by reducing Fresnel reflections at the interface between the second patterned surface and the first patterned surface and / or by reducing total internal reflections at the second major surface (e.g., light to be coupled out of the light extraction device).

[0243] In various aspects, a display device may include a dichroic mirror and / or a polarizer. Providing a dichroic mirror can increase the illumination of a backlight device, for example, by reflecting light emitted from a phosphor material layer and incident on the dichroic mirror. Providing a polarizer can increase contrast and / or reduce glare, for example, by reducing ambient light entering a sub-pixel so that it is not transmitted to an observer. Alternatively, providing a low percentage (e.g., about 66% or less, about 50% or less, about 40% or less, about 33% or less, about 25% or less) of the pixel area occupied by the sub-pixel can allow the dichroic mirror and / or polarizer to be omitted without increasing glare, reducing contrast, or reducing illumination beyond a predetermined threshold of the corresponding value.

[0244] As used herein, the terms "," an "or "an" mean "at least one" and should not be limited to "only one" unless expressly indicated to the contrary. Thus, for example, reference to "an element" includes aspects having two or more such elements unless the context clearly indicates otherwise.

[0245] As used herein, the term "about" means that the amount, size, formulation, parameter and other quantities and characteristics are not and need not be exact, but can be approximate and / or larger or smaller as needed, thereby reflecting tolerances, conversion factors, rounding, measurement errors, etc., and other factors known to those skilled in the art. When the term "about" is used to describe the endpoints of a value or range, it should be understood that the disclosure includes the specific value or endpoint referred to. If the numerical value or range endpoint in this specification records "about", then the numerical value or range endpoint is intended to include two aspects: one is modified by "about" and one is not modified by "about". It will be further understood that the endpoint of each range is significant both with respect to the other endpoint and independently of the other endpoint.

[0246] As used herein, the terms "substantial," "substantially," and variations thereof are intended to indicate that the feature is equal to or nearly equal to a value or description. For example, a "substantially planar" surface is intended to mean a planar or nearly planar surface. Additionally, as defined above, "substantially similar" is intended to mean that two values ​​are equal or approximately equal. In various aspects, "substantially similar" can mean values ​​that differ by less than about 10% from each other (e.g., values ​​that differ by less than about 5% from each other, or values ​​that differ by less than about 2% from each other).

[0247] As used herein, unless otherwise indicated, the term "include" and variations thereof should be interpreted as synonymous and open ended. A list of elements following the transitional phrase "include" is a non-exclusive list such that there may be elements other than those specifically recited in the list.

[0248] Although these aspects have been described in detail with respect to certain illustrative and specific aspects of the various aspects, the present disclosure should not be considered limited thereto since many modifications and combinations of the disclosed features are possible without departing from the scope of the appended claims.

Claims

1. A display device, comprising: a backlight device configured to emit light through a light emitting surface of the backlight device; and A light extraction device, the light extraction device comprising: a first sheet including a first major surface extending along a first plane and disposed on the light emitting surface; and a second sheet material, the second sheet material being disposed on the first sheet material, the second sheet material comprising a second major surface, the second major surface extending along a second plane parallel to the first plane, The first refractive index of the first sheet or the second refractive index of the second sheet is about 1.6 or greater, an absolute value of a difference between the first refractive index and the second refractive index is about 0.1 to about 0.4, and at least one of the following conditions exists: The first sheet material includes a first plurality of pyramid structures, and a first plurality of spaces between the first plurality of pyramid structures are filled with the second sheet material; or The second sheet includes a second plurality of pyramid structures, and a second plurality of spaces between the second plurality of pyramid structures are filled by the first sheet. 2 . The display device of claim 1 , wherein the first refractive index or the second refractive index is about 1.65 to about 1.

9.

3. The display device of any one of claims 1-2, wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures comprises a plurality of triangular pyramids, a plurality of quadrangular pyramids, a plurality of hexagonal pyramids, or a combination thereof arranged in a closely packed configuration.

4. The display device according to any one of claims 1 to 3, wherein at least one of the following conditions exists: A first base angle of a pyramid structure in the first plurality of pyramid structures is defined as an inner angle relative to the first plane, and the base angle ranges from about 60° to about 80°; or A second base angle of the pyramid structures in the second plurality of pyramid structures is defined as an interior angle relative to the second plane, and the base angle ranges from about 60° to about 80°. 5 . The display device of claim 4 , wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures comprises a plurality of quadrangular pyramids, and at least one of the first base angle or the second base angle ranges from 60° to 75°. 6 . The display device of claim 4 , wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures comprises a plurality of hexagonal pyramids, and at least one of the first base angle or the second base angle ranges from 60° to 75°.

7. The display device according to any one of claims 1 to 3, wherein at least one of the first plurality of pyramid structures or the second plurality of pyramid structures comprises a plurality of triangular pyramids, and at least one of the following conditions exists: A first base angle of a pyramid structure in the first plurality of pyramid structures is defined as an interior angle relative to the first plane, and the base angle ranges from about 50° to about 80°; or A second base angle of the pyramid structures in the second plurality of pyramid structures is defined as an interior angle relative to the second plane, and the base angle ranges from about 50° to about 80°. 8 . The display apparatus of claim 7 , wherein at least one of the first base angle or the second base angle ranges from about 50° to about 70°.

9. A display device as described in any one of claims 4-8, wherein the pyramid structure of at least one of the first plurality of pyramid structures or the second plurality of pyramid structures includes a radius of curvature of the peak of the pyramid structure, and the radius of curvature is about 20% or less of the height.

10. A display device as described in any one of claims 4 to 9, wherein the first platform height of the first sheet between the light-emitting surface of the backlight device and the base of the pyramid structure in the first plurality of pyramid structures or the peak of the pyramid structure in the second plurality of pyramid structures ranges from about 0.5 microns to about 10 microns.

11. A display device as described in any one of claims 4 to 10, wherein a second platform height of the second sheet between the second plane and the peak of the pyramid structure in the first plurality of pyramid structures or the base of the pyramid structure in the second plurality of pyramid structures ranges from about 0.5 microns to about 10 microns.

12. The display device of any one of claims 1-11, wherein the first refractive index is about 1.6 or greater, and the second refractive index is less than 1.

6.

13. The display device of any one of claims 1-11, wherein the second refractive index is approximately 1.6 or greater, and the first refractive index is less than 1.

6.

14. The display apparatus of any one of claims 1-13, wherein the light extraction device has a haze of about 1% or less.

15. The display device according to any one of claims 1 to 14, wherein the light extraction device further comprises a substrate, the substrate being arranged on the second major surface of the second sheet.

16. The display device according to any one of claims 1 to 15, wherein the backlight device comprises: Multiple light sources; A color converter comprising a plurality of pixels positioned between the plurality of light sources and the light emitting surface, one of the plurality of pixels comprising three sub-pixels, each sub-pixel being defined by a plurality of walls, one of the three sub-pixels comprising: a phosphorescent material layer; as well as An absorptive color filter, the phosphor material layer is positioned between the plurality of light sources and the absorptive color filter, a major surface of the absorptive color filter and major surfaces of the plurality of walls extending along a common plane.

17. The display device of claim 16, wherein the phosphorescent material layer comprises a quantum dot phosphor in a polymeric matrix.

18. The display device of claim 17, wherein the phosphor material layer has a thickness ranging from about 3 micrometers to about 10 micrometers.

19. The display device of any one of claims 16-18, wherein the thickness of the sub-pixel ranges from about 8 microns to about 30 microns.

20. A display device as described in any one of claims 16-19, wherein the area of ​​the light emitting surface for the pixel corresponding to the main surface of the absorptive filter of the three sub-pixels is approximately 50% or less, and the light emitting surface is defined by the main surface of the absorptive filter and the main surfaces of the plurality of walls.

Images