Display device

Abstract

A display device includes a display panel, an opposing substrate, a medium layer and an optical layer. The display panel has a first upper surface and a first lower surface relative to the first upper surface. The opposing substrate has a second upper surface and a second lower surface relative to the second upper surface, where the second lower surface and the first upper surface are placed on the first lower surface and the second upper surface. The medium layer is placed between the display panel and the opposing substrate. The optical layer is placed between the display panel and the opposing substrate and placed on the first upper surface of the display panel, where a specular reflectivity of the optical layer is between

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a display device with anti-reflection and anti-glare properties. Prior Technology

[0002] Specular reflections from existing display devices create ghosting, which distorts the image displayed and hinders user viewing. Furthermore, display devices can produce glare due to ambient light, causing visual discomfort. While some display devices feature anti-reflective coatings (AR coatings) and anti-glare films (AG films), the image quality of these devices remains limited by specular reflections and glare, hindering further improvements. Summary of the Invention

[0003] At least one embodiment of the present invention provides a display device that helps to improve the image quality of the display device.

[0004] At least one embodiment of the present invention provides a display device, including a display panel, a counter substrate, a dielectric layer, and an optical layer. The display panel has a first upper surface and a first lower surface opposite to the first upper surface. The counter substrate has a second upper surface and a second lower surface opposite to the second upper surface, wherein the second lower surface and the first upper surface are located on the first lower surface and the second upper surface. The dielectric layer is disposed between the display panel and the counter substrate. The optical layer is located between the display panel and the counter substrate and is disposed on the first upper surface of the display panel, wherein the specular reflectivity of the display device is between 1.2% and 2.5%.

[0005] In at least one embodiment of the present invention, the above-mentioned medium layer is air.

[0006] In at least one embodiment of the present invention, the thickness of the dielectric layer is from 0.5 mm to 20 mm.

[0007] In at least one embodiment of the present invention, the thickness of the optical layer is less than or equal to 0.2 mm.

[0008] In at least one embodiment of the present invention, an anti-reflective layer is further included. The anti-reflective layer is disposed on the second lower surface of the opposing substrate, wherein the haze of the anti-reflective layer is less than the haze of the optical layer.

[0009] In at least one embodiment of the present invention, the haze of the anti-reflective layer is less than 3%.

[0010] In at least one other embodiment of the present invention, the aforementioned medium layer is a colloid.

[0011] In at least one other embodiment of the present invention, the thickness of the aforementioned dielectric layer is 1 to 20 times the thickness of the optical layer.

[0012] In at least one other embodiment of the present invention, the thickness of the optical layer is 0.1 mm to 0.2 mm.

[0013] In at least one other embodiment of the present invention, the optical layer is a diffusion film.

[0014] Based on the above, in the display device disclosed in the above embodiments of the present invention, a dielectric layer and an optical layer are disposed between the display panel and the opposing substrate, and the optical layer is disposed on the first upper surface of the display panel, so that the specular reflectivity of the display device is between 1.2% and 2.5%, which helps to improve the image quality of the display device. Simple Explanation of the Diagram

[0015] To make the above and other features, advantages and embodiments of the present invention more apparent and understandable, the detailed description of the accompanying drawings is as follows: Figure 1 is a cross-sectional schematic diagram of a display device according to at least one embodiment of the present invention. Figure 2 is a cross-sectional schematic diagram of a display device according to at least one other embodiment of the present invention. Figure 3 is an enlarged cross-sectional schematic diagram of the optical layer of at least one embodiment of the present invention. Figure 4 is a three-dimensional schematic diagram of the protruding structure of the optical layer in Figure 3. Figure 5 is a height statistics diagram of the third upper surface of the optical layer in Figure 3. Implementation

[0016] In the following text, to clearly present the technical features of this application, the dimensions (e.g., length, width, thickness, and depth) of the elements (e.g., layers, films, substrates, and regions) in the drawings will be enlarged proportionally, and the number of some elements may be reduced. Therefore, the description and explanation of the embodiments below are not limited to the number of elements in the drawings or the size and shape of the elements, but should cover the size, shape, and deviations from both caused by actual manufacturing processes and / or tolerances. For example, a flat surface shown in the drawings may have rough and / or non-linear characteristics, and an acute angle shown in the drawings may be rounded. Therefore, the elements presented in the drawings of this application are mainly for illustration and are not intended to accurately depict the actual shape of the elements, nor are they intended to limit the scope of the claims in this application.

[0017] It should be understood that although the terms "first," "second," "third," etc., in this disclosure may be used to describe various components, elements, areas, layers, parts, and / or segments, these components, elements, areas, layers, parts, and / or segments should not be limited by these terms. These terms are used only to distinguish one component, element, area, layer, part, or segment from another. Therefore, the first component, element, area, layer, part, or segment described below may be referred to as the second component, element, area, layer, part, or segment without departing from the teachings of this disclosure.

[0018] Figure 1 is a cross-sectional schematic diagram of a display device 100 according to at least one embodiment of the present invention. Referring to Figure 1, the display device 100 includes a display panel 110, a counter substrate 120, a dielectric layer 130, and an optical layer 140. The display panel 110 has a first upper surface 112 and a first lower surface 114 opposite to the first upper surface 112. The counter substrate 120 has a second upper surface 122 and a second lower surface 124 opposite to the second upper surface 122, wherein the second lower surface 124 and the first upper surface 112 are located at the first lower surface 114 and the second upper surface 122. The dielectric layer 130 is disposed between the display panel 110 and the counter substrate 120. The optical layer 140 is located between the display panel 110 and the counter substrate 120 and is disposed on the first upper surface 112 of the display panel 110.

[0019] The display panel 110 can be a non-self-emissive display panel, such as a liquid crystal display (LCD). Therefore, the display device 100 may also include a backlight module (not shown), wherein the display panel 110 is disposed between the backlight module and the opposing substrate 120. Alternatively, the display panel 110 can also be a self-emissive display panel, such as an organic light-emitting diode (OLED) display panel or a micro-LED display panel, so the display device 100 may not include the aforementioned backlight module.

[0020] The opposing substrate 120 can be a transparent protective substrate (cover lens), and its constituent material can be glass or sapphire substrate. Alternatively, the opposing substrate 120 can also be a display panel that is permeable to light, such as a liquid crystal display panel or a transparent display.

[0021] The dielectric layer 130 is air, meaning that the constituent material of the dielectric layer 130 can be air. In the embodiment shown in FIG1, the display device 100 may further include a sealant 160, wherein the sealant 160 is disposed between the opposing substrate 120 and the display panel 110, and adheres the opposing substrate 120 and the display panel 110. The sealant 160 surrounds an air-filled cavity, and the dielectric layer 130 is the air within this cavity.

[0022] The thickness W1 of the dielectric layer 130 is 0.5 mm to 20 mm, and the thickness W2 of the optical layer 140 can be less than or equal to 0.2 mm. For example, the thickness W1 of the dielectric layer 130 can be 10 mm to 20 mm, or 10 mm, 15 mm, or 20 mm. The thickness W2 can be 0.1 mm to 0.2 mm, or 0.1 mm, 0.15 mm, or 0.2 mm.

[0023] Optical layer 140 can be an anti-reflective film. Alternatively, optical layer 140 can have both anti-glare and anti-reflective functions, i.e., optical layer 140 can be an anti-glare and anti-reflective film. When optical layer 140 is an anti-glare and anti-reflective film, optical layer 140 may include anti-glare and anti-reflective films stacked on top of each other. The haze of optical layer 140 is greater than or equal to 30%, and preferably 60% to 70%. In this way, specular reflection light can be reduced, further reducing the generation of ghosting and glare.

[0024] Furthermore, when the optical layer 140 is an anti-glare and anti-reflection film, the gloss of the optical layer 140 at a measurement angle of 20 degrees (G20) can be less than or equal to 1 GU, the gloss at a measurement angle of 60 degrees (G60) can be less than or equal to 6 GU, and the gloss at a measurement angle of 85 degrees (G85) can be less than or equal to 40 GU.

[0025] The display device 100 further includes an anti-reflective layer 150 disposed on the second lower surface 124 of the opposing substrate 120, wherein a dielectric layer 130 is located between the anti-reflective layer 150 and the optical layer 140. The haze of the anti-reflective layer 150 is less than that of the optical layer 140, wherein the haze of the anti-reflective layer 150 may be less than 3%, and a glossy surface is preferred to maintain image clarity.

[0026] The antireflective layer 150 can be formed by utilizing the reflectivity changes caused by surface structures and shapes such as surface undulations of the material. For example, a similar structure—a subwavelength structure—can be created by referencing a moth's eye. According to the effective medium theory (EMT), its refractive index is equivalent to that of a multilayer thin film with a gradually changing refractive index. Alternatively, the antireflective layer 150 can also be an interference filter with a multilayer film structure, allowing it to reduce light reflectivity using the principle of optical interference.

[0027] In the embodiment shown in FIG1, the display device 100 includes only one anti-reflective layer 150. However, in other embodiments, the display device 100 includes at least two anti-reflective layers 150, one anti-reflective layer 150 disposed on the second lower surface 124 and the other anti-reflective layer 150 disposed on the second upper surface 122. That is, these anti-reflective layers 150 are respectively disposed on opposite sides of the opposing substrate 120. Furthermore, in other embodiments, the optical layer 140 disposed on the first upper surface 112 of the display panel 110 may be the same as the anti-reflective layer 150.

[0028] Figure 2 is a cross-sectional schematic diagram of a display device 200 according to at least one other embodiment of the present invention. Referring to Figure 2, the display device 200 includes a display panel 110, a counter substrate 120, a dielectric layer 230, and an optical layer 240. The arrangement structure of the display panel 110, the counter substrate 120, the dielectric layer 230, and the optical layer 240 is similar to that in Figure 1, and the thickness W3 of the dielectric layer 230 can also be 1 to 20 times the thickness W4 of the optical layer 240.

[0029] However, the dielectric layer 230 is a colloid rather than air, and the colloid can be a water-based adhesive or an optically clear adhesive (OCA). Alternatively, the colloid may include both water-based and optically clear adhesives. Furthermore, the aforementioned colloid has adhesive properties, so the dielectric layer 230 can bond the display panel 110 and the opposing substrate 120. Thus, unlike the aforementioned display device 100, the display device 200 does not require the frame adhesive 160 to connect the display panel 110 and the opposing substrate 120.

[0030] The thickness W4 of the optical layer 240 is 0.1 mm to 0.2 mm, and the optical layer 240 can be a diffusion film with internal haze of scattering particles. The optical layer 240 may include a coating and multiple scattering particles distributed in the coating. When the optical layer 240 passes through a medium with different refractive indices (i.e., scattering particles and coating), it will produce phenomena such as refraction, reflection, and scattering, changing the direction of light travel and causing a haze effect. The haze of the optical layer 240 is greater than or equal to 60%, for example, 60% to 80%, with 70% to 80% being preferred. This can reduce specular reflection light and further reduce the generation of ghosting and glare. The display device 200 further includes an anti-reflective layer 150. The anti-reflective layer 150 is disposed on the second upper surface 122 of the opposing substrate 120, wherein the haze of the anti-reflective layer 150 is less than the haze of the optical layer 240, and can be less than 3%.

[0031] The specular reflectance of display devices 100 and 200 is individually between 1.2% and 2.5%, and Table 1 below discloses the specular reflectance of display devices according to various embodiments of the present invention. It must be emphasized that the content disclosed in Table 1 is not intended to limit the specular reflectance of display devices 100 and 200. That is, in other embodiments, the display devices may have a specular reflectance between 1.2% and 2.5%, but not disclosed in Table 1, such as 1.2%, 2%, or 2.5%.

[0032] Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of this invention. Comparative Example 1 Experimental Example 1 experiment Example 2 experiment Example 3 Comparative Example 2 experiment Example 4 Interface layer Air colloid Optical layer none Anti-reflective film generally Anti-glare and anti-reflective film high quality Anti-glare and anti-reflective film none diffusion membrane Reflectance including specular reflection mode (SCI) (%) 5.90 2.27 3.25 2.06 2.82 2.67 Reflectivity under Specular Contrast (SCE) mode (%) 0.08 0.10 1.49 0.50 0.07 1.40 Mirror reflectivity (SCI- SCE) (%) 5.82 2.17 1.76 1.56 2.75 1.27 Table 1

[0033] Please refer to Table 1. Comparative Examples 1 and Experimental Examples 1 to 3 correspond to display device 100, meaning that the dielectric layer 130 included in the display devices of Comparative Examples 1 and 1 to 3 is air. The display device of Comparative Example 1 does not have optical layers 140 and 240. The display devices of Comparative Examples 1 and 1 to 3 include optical layer 140. The reflectance of Comparative Example 1 is 5.90% in the specular component include (SCI) mode and 0.08% in the specular component exclude (SCE) mode. Therefore, the specular reflectance of Comparative Example 1 (the difference between SCI and SCE, i.e., SCI-SCE) is 5.82%.

[0034] In Experimental Example 1, the optical layer 140 is an anti-reflective film. The optical layer 140 disposed on the first upper surface 112 of the display panel 110 can be the same as the anti-reflective layer 150. The reflectivity of Experimental Example 1 is 2.27% in the specular reflection mode (SCI) and 0.10% in the non-specular reflection mode (SCE). The specular reflectivity (SCI-SCE) is 2.17%.

[0035] In Experiments 2 and 3, the optical layer 140 is an anti-glare and anti-reflection film. When the optical layer 140 is a general anti-glare and anti-reflection film, the reflectivity of Experiment 2 is 3.25% in the specular reflection mode (SCI) and 1.49% in the non-specular reflection mode (SCE), while the specular reflectivity (SCI-SCE) is 1.76%. Among them, the reflectivity of the optical layer 140 of Experiment 2 (i.e., the general anti-glare and anti-reflection film) in the specular reflection mode (SCI) is 1.5%.

[0036] When the optical layer 140 is a high-quality anti-glare and anti-reflection film, the reflectivity of Experimental Example 3 is 2.06% in the specular reflection mode (SCI) and 0.50% in the non-specular reflection mode (SCE), while the specular reflectivity (SCI-SCE) is 1.56%. Among them, the reflectivity of the optical layer 140 (i.e., the high-quality anti-glare and anti-reflection film) in Experimental Example 3 in the specular reflection mode (SCI) is 0.5%. As can be seen from Experimental Examples 1 to 3 in Table 1, the specular reflectivity of the display device 100 is not only between 1.2% and 2.5%, but also between 1.5% and 2.2%, for example, between 1.56% and 2.17%.

[0037] Please refer to Table 1 and the corresponding Figure 2 for the display device 200. The dielectric layer 230 in Comparative Example 2 and Experimental Example 4 is a colloid. Comparative Example 2 does not have any optical layers 140 and 240 disposed between the display panel 110 and the opposing substrate 120. The reflectance of Comparative Example 2 is 5.90% in the specular reflection mode (SCI), 0.07% in the non-specular reflection mode (SCE), and 2.75% in the specular reflection (SCI-SCE) mode.

[0038] In Example 4, the optical layer 240 can be a diffusion film, located between the display panel 110 and the opposing substrate 120, and disposed on the first upper surface 112 of the display panel 110. Example 4 has a reflectivity of 2.67% in the specular reflection mode (SCI), 1.40% in the non-specular reflection mode (SCE), and a specular reflectivity (SCI-SCE) of 1.27%. As can be seen from Example 4 in Table 1, the specular reflectivity of the display device 200 is indeed between 1.2% and 2.5%, for example, 1.27%.

[0039] Figure 3 is an enlarged cross-sectional schematic diagram of the optical layer 340 according to at least one embodiment of the present invention. Referring to Figure 3, the optical layer 340 can be applied to the display device 100 in the foregoing embodiments, wherein the optical layer 340 may have a haze greater than or equal to 60%, for example, 60% to 80%, and has a third upper surface 344 and a third lower surface 345 relative to the third upper surface 344. The third upper surface 344 includes a plurality of protrusion structures 342, and is formed by connecting these protrusion structures 342.

[0040] The protrusion structure 342 can be generated simultaneously with the formation of the optical layer 340 using injection molding technology, or by removing part of the optical layer 340 through etching, machining, sandblasting, or other methods. The third upper surface 344 is a rough surface, and the third lower surface 345 is a smooth surface. In addition, an anti-reflective film can be formed on the optical layer 340 to form an anti-glare and anti-reflective film that can serve as the optical layer 140.

[0041] Figure 4 is a three-dimensional schematic diagram of the protrusion structure 342 of the optical layer 340 in Figure 3. For ease of explanation, Figure 4 schematically illustrates the XYZ Cartesian coordinate system, where the directions X, Y, and Z are orthogonal. Figure 4 depicts the Z-axis of the XYZ Cartesian coordinate system, and values ​​are also marked on this Z-axis, ranging from 0 to 100. It must be noted that the values ​​on the Z-axis are not units of length such as millimeters or micrometers. Furthermore, Figure 4 also marks the vertices of the protrusion structure 342. For example, the coordinates of the highest vertex of the protrusion structure 342 in Figure 4 are marked as "X:2", "Y:2", and "Z:100", that is, the coordinates of the highest vertex are (2, 2, 100). Similarly, the coordinates of the lowest vertex of the protrusion structure 342 are marked as "X:1", "Y:1", and "Z:0", that is, the coordinates of the lowest vertex are (1, 1, 0).

[0042] As shown in Figure 4, each protruding structure 342 has multiple inclined surfaces 346. The normal direction N of each of these inclined surfaces 346 forms an angle θ with the normal direction N of the third lower surface 345. Furthermore, the shape of each protruding structure 342 can be different, and the degree of inclination of the inclined surfaces 346 of each protruding structure 342 can also be different; that is, the multiple angles θ corresponding to these inclined surfaces 346 may not be the same, and this invention is not limited thereto.

[0043] This invention uses a 3D microscope to measure the surface, employing a horizontal resolution of 92.7 nm and a high resolution of 0.1 nm (parallel to the third lower surface 345). The analyzed area varies depending on the protrusion size; in one embodiment, the analysis range exceeds 200 μm x 300 μm. The measurement result is a height array of equidistant grids on the horizontal plane. Using this height array as coordinates based on the equidistant grids on the horizontal plane, three adjacent coordinate points form a surface, allowing the calculation of the angle θ between the slope normal direction N and the horizontal normal direction H. Every three adjacent points have the same projected area on the third lower surface 345. The area ratio is obtained by dividing the number of data points calculated within the statistical interval of the angle θ by the total number of measurements.

[0044] Vertical projection is defined as the projection of the third upper surface 344 onto the third lower surface 345 by parallel light rays traveling along the Z-axis onto the protruding structure 342. Therefore, the projection of the inclined surfaces 346 of the third upper surface 344 onto the third lower surface 345 along the Z-axis is the vertical projection. The sum of the vertical projection areas of these inclined surfaces 346 with corresponding angles θ less than 2.5° on the third lower surface 345 is P, and the total vertical projection area of ​​all inclined surfaces 346 on the third lower surface 345 is T, where P / T ≦ 3.58%. On the other hand, as shown in Figure 4, the minimum Z-value in the measured height data is defined as 0, and the maximum Z-value is defined as 100. Since the horizontal distance between the measured height data points is equidistant, the number of data points within a height range divided by the total number of data points equals the proportion of the projected area of ​​that height on the third lower surface 345.

[0045] Figure 5 is a height statistics diagram of the third upper surface 344 of the optical layer 140 in Figure 3. In simple terms, Figure 5 is a statistical diagram of the height data in each interval divided by the total data volume. In this invention, the height of the protruding structure 342 corresponding to the area proportion with the largest distribution is defined as the "peak height," the maximum value between all height data and the Z=0 plane (i.e., the XY plane) (i.e., a Z value of 100) is defined as the "total height," and the sum of all height data divided by the total data volume is defined as the "average height."

[0046] Among these inclined surfaces 346, the sum of the vertical projected areas of the portions with included angles θ ≤ 35° on the third lower surface 345 is Q, where Q / T ≥ 86%, and T is the vertical projected area of ​​all inclined surfaces 346 on the third lower surface 345. In the statistical analysis of the height data of the equidistant grids measured within the measurement range on the third upper surface 344, the interval with the largest number of measurements is defined as the peak height, and the ratio of this peak height to the average of these height data is ≤ 0.92.

[0047] When Q / T ≥ 91.16%, the interval with the most frequent occurrences in the height data statistics of the equidistant grids measured within the measurement range of the third upper surface 344 is defined as the peak height, and the ratio of this peak height to the average of these height data is ≤ 0.97. However, when Q / T ≥ 94.58%, the interval with the most frequent occurrences in the height data statistics of the equidistant grids measured within the measurement range of the third upper surface 344 is defined as the peak height, and the ratio of this peak height to the average of these height data is ≤ 1.39.

[0048] In summary, in the display devices 100 and 200 of at least one embodiment of the present invention, dielectric layers 130 and 230 and optical layers 140 and 240 are disposed between the display panel 110 and the opposing substrate 120, and dielectric layers 130 and 230 can be either air or colloid, so that the specular reflectivity of the display devices 100 and 200 is between 1.5% and 2.5%, which helps to improve the image quality of the display devices 100 and 200. Furthermore, in the display device 100, an anti-reflective layer 150 can be disposed on the second lower surface 124 of the opposing substrate 120 where the dielectric layer 130 is air, to more effectively reduce or suppress specular reflection light, reduce ghosting and glare, and further improve the image quality of the display device 100.

[0049] While this application has disclosed various embodiments above, it is not intended to limit this application. The components of several embodiments are outlined above to facilitate a better understanding of the inventive embodiments by those skilled in the art. Those skilled in the art should understand that they can design or modify other processes and structures based on the embodiments of this invention to achieve the same purpose as the embodiments described herein. Those skilled in the art should also understand that such equivalent processes and structures do not depart from the spirit and scope of this invention, and that various changes, substitutions, and replacements can be made without departing from the spirit and scope of this invention. Therefore, the scope of protection of this application shall be determined by the appended claims.

[0050] 100, 200: Display devices 110: Display panel 112: First upper surface 114: First lower surface 120: Opposing substrate 122: Second upper surface 124: Second lower surface 130, 230: Dielectric layer 140, 240, 340: Optical layer 150: Anti-reflective layer 160: Frame adhesive 342: Protruding structure 344: Third upper surface 345: Third lower surface 346: Incline N: Direction of the normal to the inclined plane H: Direction of the horizontal plane normal W1, W2, W3, W4: Thickness θ: included angle X, Y, Z: Axes

Claims

1. A display device, comprising: A display panel having a first upper surface and a first lower surface relative to the first upper surface; A pair of opposing substrates, having a second upper surface and a second lower surface opposite to the second upper surface, wherein the second lower surface and the first upper surface are located between the first lower surface and the second upper surface; a dielectric layer disposed between the display panel and the opposing substrate; an optical layer located between the display panel and the opposing substrate, and disposed on the first upper surface of the display panel, wherein the specular reflectivity of the display device is between 1.2% and 2.5%; And an anti-reflective layer disposed on the second lower surface of the opposing substrate, wherein the haze of the anti-reflective layer is less than the haze of the optical layer.

2. The display device as claimed in claim 1, wherein the medium layer is air.

3. The display device as claimed in claim 2, wherein the thickness of the dielectric layer is from 0.5 mm to 20 mm.

4. The display device as claimed in claim 2, wherein the thickness of the optical layer is less than or equal to 0.2 mm, the gloss of the optical layer at a measurement angle of 20 metric degrees is less than or equal to 1 GU, the gloss of the optical layer at a measurement angle of 60 metric degrees is less than or equal to 6 GU, and the gloss of the optical layer at a measurement angle of 85 metric degrees is less than or equal to 40 GU.

5. The display device as claimed in claim 1, wherein the haze of the antireflective layer is less than 3%.

6. The display device as claimed in claim 1, wherein the dielectric layer is a colloid.

7. The display device as claimed in claim 6, wherein the thickness of the optical layer is 0.1 mm to 0.2 mm.

8. The display device as claimed in claim 6, wherein the thickness of the dielectric layer is 1 to 20 times the thickness of the optical layer.

9. The display device as claimed in claim 6, wherein the optical layer is a diffusion film.

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