Reflective display device

Abstract

A reflective display device includes a substrate, a refractive index matching layer, and a transparent conductive layer. The refractive index matching layer is disposed on the substrate, and the transparent conductive layer is disposed on the refractive index matching layer. According to the CIE L*a*b* color model, the reflected light caused by the refractive index matching layer and the transparent conductive layer satisfies one of the following conditions (a) to (d): (a) the b* of the reflected light is greater than 5, and the a* of the reflected light is greater than or equal to -5 and less than or equal to 5; (b) the b* of the reflected light is less than -5, and the a* of the reflected light is greater than or equal to -5 and less than or equal to 5; (c) the a* of the reflected light is greater than 5, and the b* of the reflected light is greater than or equal to -5 and less than or equal to 5; and (d) the a* of the reflected light is less than -5, and the b* of the reflected light is greater than or equal to -5 and less than or equal to 5.

Description

Technical Field

[0001] This invention relates to a reflective display device, and more particularly to a reflective display device with a suitable background color. Background Technology

[0002] Electronic devices are indispensable products today, and display devices with display functions, such as screens, laptops, smartphones, wearable devices, smartwatches, and automotive displays, are widely used in many places. Since display devices are used to display images, the background color of the display device (i.e., the color of the reflected light that is directly reflected by the structure of the display area) affects the quality of the displayed image, and thus the user's viewing experience. For example, when the background color of the display device is yellowish, yellow text and / or yellow graphics will be less clear, and blue text and / or blue graphics will appear more blackish. Therefore, display devices should have an appropriate background color to obtain a high-quality display. Summary of the Invention

[0003] The purpose of this invention is to provide a reflective display device that has an appropriate background color by designing a refractive index matching layer and a transparent conductive layer.

[0004] To address the aforementioned technical problems, this invention provides a reflective display device, comprising a substrate, a refractive index matching layer, and a transparent conductive layer. The refractive index matching layer is disposed on the substrate, and the transparent conductive layer is disposed on the refractive index matching layer. According to the CIE L*a*b* color model, the reflected light caused by the refractive index matching layer and the transparent conductive layer satisfies one of the following conditions (a) to (d): (a) the b* of the reflected light is greater than 5, and the a* of the reflected light is greater than or equal to -5 and less than or equal to 5; (b) the b* of the reflected light is less than -5, and the a* of the reflected light is greater than or equal to -5 and less than or equal to 5; (c) the a* of the reflected light is greater than 5, and the b* of the reflected light is greater than or equal to -5 and less than or equal to 5; (d) the a* of the reflected light is less than -5, and the b* of the reflected light is greater than or equal to -5 and less than or equal to 5.

[0005] According to the design of the refractive index matching layer and the transparent conductive layer of the present invention, the reflective display device can have an appropriate background color as needed, and the light utilization rate can be improved by increasing the light transmittance of the background color adjustment structure. Attached Figure Description

[0006] Figure 1 The figure shown is a cross-sectional schematic diagram of a reflective display device according to a first embodiment of the present invention.

[0007] Figure 2 The image shows the chromaticity diagram of the reflected light from the transparent conductive layer at different thicknesses according to the CIEL*a*b* color model, as an embodiment of the present invention.

[0008] Figure 3 The diagram shown illustrates the relationship between the thickness of the transparent conductive layer and the light reflectivity according to an embodiment of the present invention.

[0009] Figure 4 The diagram shown is a schematic diagram of the relationship between the wavelength of the reflected light from the light-reflecting layer and its corresponding light reflectivity according to an embodiment of the present invention.

[0010] Figure 5 The figure shown is a cross-sectional schematic diagram of a reflective display device according to a second embodiment of the present invention.

[0011] Figure 6 The figure shown is a cross-sectional schematic diagram of a reflective display device according to a third embodiment of the present invention.

[0012] Figure 7 The figure shown is a cross-sectional schematic diagram of a reflective display device according to a fourth embodiment of the present invention.

[0013] Figure 8 The figure shown is a cross-sectional schematic diagram of a reflective display device according to the fifth embodiment of the present invention.

[0014] Explanation of reference numerals in the attached drawings: 100, 200, 300, 400, 500 - reflective display device; 110 - substrate; 120 - refractive index matching layer; 122 - first matching layer; 124 - second matching layer; 130 - transparent conductive layer; 140 - light reflective layer; 312 - color conversion layer; 312a, 312b, 312c - color conversion unit; 410 - cover layer; CA - background color adjustment structure; X, Y, Z - directions. Detailed Implementation

[0015] To enable those skilled in the art to further understand the present invention, preferred embodiments of the present invention are described below, along with a detailed description of the invention's structure and desired effects in conjunction with the accompanying drawings. It should be noted that the accompanying drawings are simplified schematic diagrams; therefore, only elements and combinations related to the present invention are shown to provide a clearer description of the basic structure or implementation method of the present invention, while the actual elements and layout may be more complex. Furthermore, for ease of explanation, the elements shown in the various drawings of the present invention are not drawn to scale according to the actual number, shape, and size; the detailed scale can be adjusted according to design requirements.

[0016] In the following description and claims, the terms "comprising," "containing," and "having" are open-ended terms and should therefore be interpreted as "containing but not limited to...". Thus, when the terms "comprising," "containing," and / or "having" are used in the description of this invention, they specify the presence of the corresponding features, areas, steps, operations, and / or components, but do not exclude the presence of one or more of the corresponding features, areas, steps, operations, and / or components.

[0017] In the following description and claims, when “A1 component is formed by B1”, it means that the formation of A1 component includes or uses B1, and the formation of A1 component does not exclude the presence or use of one or more other features, areas, steps, operations and / or components.

[0018] In the following description and claims, the term "horizontal direction" refers to a direction parallel to a horizontal plane; the term "horizontal plane" refers to a surface parallel to directions X and Y in the drawings; and the term "vertical direction" refers to a direction parallel to direction Z in the drawings, wherein directions X, Y, and Z are perpendicular to each other. In the description and claims, the term "top view" refers to the result of viewing along the vertical direction, and the term "section" refers to the result of viewing a structure cut along the vertical direction from a horizontal perspective.

[0019] In the specification and claims, the term "parallel" means that the angle between two components may be less than or equal to a specific angle, such as 5 degrees, 3 degrees or 1 degree.

[0020] In the following description and claims, the term “overlap” means that two components overlap in the direction Z, and unless otherwise specified, the term “overlap” includes partial or complete overlap, wherein the two components may be in direct contact with each other or there may be a spacer between the two components.

[0021] The ordinal numbers used in the specification and claims, such as "first," "second," etc., to modify elements, do not in themselves imply or represent any prior ordinal number for that element (or those elements), nor do they represent the order of one element with another, or the order of manufacturing processes. The use of these ordinal numbers is solely to clearly distinguish one named element from another element with the same name. The claims and specification may not use the same terminology; therefore, a first element in the specification may be a second element in the claims.

[0022] It should be understood that the features described below can be replaced, recombined, or mixed in several different embodiments to complete other embodiments without departing from the spirit of the invention. Features between embodiments can be arbitrarily mixed and combined as long as they do not violate the spirit of the invention or conflict with it.

[0023] The reflective display device of the present invention may be a non-self-emissive reflective display, wherein examples of non-self-emissive reflective displays may include liquid crystal molecules, colloidal materials used for electrophoresis, or other suitable display medium materials, but are not limited thereto. For example, the reflective display device may be an electrically controlled birefringence (ECB) reflective display, but is not limited thereto. The shape of the reflective display device may be polygonal (e.g., rectangular), a shape with curved edges (e.g., circular, elliptical), or other suitable shapes, but is not limited thereto.

[0024] A reflective display device may have a display area and a peripheral area disposed on at least one outer side of the display area, wherein the display area is used for displaying an image, and electronic components (e.g., driving circuits, chips, conductive particles, etc.) used to assist the display area may be disposed in the peripheral area. For example, the peripheral area may surround the active area, but is not limited thereto.

[0025] A reflective display device may include multiple pixels as units for displaying an image, wherein each pixel may include at least one sub-pixel. In some embodiments, if the reflective display device is a color display, a pixel may include multiple sub-pixels, such as green, red, and blue sub-pixels, but is not limited thereto; the number and color of sub-pixels may be varied as needed. In some embodiments, if the reflective display device is a monochrome display, a pixel may include only one sub-pixel, but is not limited thereto. For example, the color of a sub-pixel may be designed through the arrangement of a color conversion layer and / or display medium in the reflective display device, but is not limited thereto.

[0026] Please refer to Figure 1 , Figure 1 The diagram shown is a cross-sectional view of a reflective display device according to a first embodiment of the present invention, wherein... Figure 1 The reflective display device shown is only partially depicted. For example... Figure 1As shown, the reflective display device 100 may include a substrate 110 (or a first substrate), wherein the substrate 110 may be a rigid substrate or a flexible substrate, and may include, depending on its type, materials such as glass, plastic, quartz, sapphire, polyimide (PI), polyethylene terephthalate (PET), other suitable materials or combinations thereof, but not limited thereto. Furthermore, the shape and size of the substrate 110 may be designed as needed, wherein the shape of the substrate 110 may be polygonal (e.g., rectangular), a shape with curved edges (e.g., circular, elliptical), or other suitable shapes, but not limited thereto. It should be noted that in Figure 1 In the middle, the normal direction of the substrate 110 is parallel to the direction Z.

[0027] like Figure 1 As shown, the reflective display device 100 may include a refractive index matching layer 120 disposed on a substrate 110. For example, the refractive index matching layer 120 may directly contact the substrate 110, but is not limited thereto. In this invention, the refractive index matching layer 120 may include any suitable material. For example, the refractive index matching layer 120 may include niobium oxide (e.g., niobium pentoxide (Nb₂O₅)), silicon oxide (e.g., silicon dioxide (SiO₂)), other suitable transparent insulating materials, or combinations thereof, but is not limited thereto. Furthermore, in this invention, the refractive index matching layer 120 may be a single-layer structure or a multi-layer structure as required. For example, the refractive index matching layer 120 may be a multi-layer structure including niobium oxide and silicon oxide, a single-layer structure including niobium oxide, or a single-layer structure including silicon oxide, but is not limited thereto.

[0028] In this embodiment, the reflective display device 100 may include a display medium layer (not shown), wherein the display medium layer may include suitable materials depending on the type of reflective display device 100, such as liquid crystal molecules, colloidal materials for electrophoresis, or other suitable display medium materials, but is not limited thereto. The display medium material included in the display medium layer can be adjusted in any suitable manner to adjust the state (e.g., light transmittance) of the portion corresponding to each sub-pixel in the display medium layer. For example, in some embodiments, the light transmittance of the display medium layer can be controlled by an electric field and / or an electrical signal.

[0029] In this invention, the electrodes used to control the state of the display medium layer can be designed as needed. For example, multiple electrodes used to control the display medium layer can be disposed on opposite sides of the display medium layer (i.e., the display medium layer is disposed between the electrodes), but this is not a limitation. For example, multiple electrodes used to control the display medium layer can be disposed on the same side of the display medium layer, but this is not a limitation. It should be noted that each sub-pixel may include at least two electrodes used to control the display medium layer so that the light transmittance of the corresponding sub-pixel portion in the display medium layer can be adjusted according to the electrical signal (e.g., grayscale signal) received by the electrodes, but this is not a limitation. In the following description, the electrodes used to control the display medium layer are described as being disposed on opposite sides of the display medium layer.

[0030] like Figure 1 As shown, the reflective display device 100 may include a transparent conductive layer 130 disposed on a refractive index matching layer 120, such that the refractive index matching layer 120 is disposed between the substrate 110 and the transparent conductive layer 130, and the transparent conductive layer 130 may be disposed between the display medium layer and the refractive index matching layer 120. For example, in Figure 1 In this process, the transparent conductive layer 130 may directly contact the refractive index matching layer 120 (e.g., one surface of the refractive index matching layer 120 may directly contact the substrate 110, and the other surface of the refractive index matching layer 120 may directly contact the transparent conductive layer 130), but this is not a limitation.

[0031] In this invention, the material of the transparent conductive layer 130 may include indium tin oxide (ITO), indium zinc oxide (IZO), other suitable transparent conductive materials, or combinations thereof. For example, the transparent conductive layer 130 of this embodiment may include indium tin oxide, but is not limited thereto. In some embodiments, the transparent conductive layer 130 may include at least one transparent electrode as an electrode for controlling the state of the display medium layer (e.g., light transmittance).

[0032] like Figure 1As shown, the reflective display device 100 may include a light-reflecting layer 140 disposed on the opposite side of the transparent conductive layer 130 relative to the substrate 110. For example, a display medium layer may be disposed between the transparent conductive layer 130 and the light-reflecting layer 140, but this is not a limitation. For example, the reflective display device 100 may include another substrate (or a second substrate) disposed opposite to the substrate 110, and the light-reflecting layer 140 may be disposed on the other substrate, such that the refractive index matching layer 120, the transparent conductive layer 130, the display medium layer, and the light-reflecting layer 140 may be disposed between the substrate 110 and the other substrate, but this is not a limitation. Furthermore, the material of the light-reflecting layer 140 may include any suitable material as needed. For example, the light-reflecting layer 140 may include silver, aluminum, other suitable metallic materials, or combinations thereof, but this is not a limitation. In some embodiments, the light-reflecting layer 140 may, for example, include at least one reflective conductive electrode as an electrode for controlling the state of the display medium layer (e.g., light transmittance).

[0033] In this embodiment, the state of the display medium layer (e.g., light transmittance) can be controlled by the transparent electrode of the transparent conductive layer 130 and the reflective conductive electrode of the light reflective layer 140. For example, the reflective conductive electrode of the light reflective layer 140 can receive a grayscale signal, and the transparent electrode of the transparent conductive layer 130 can receive a common signal to control the light transmittance of the display medium layer, but this is not a limitation.

[0034] In this invention, ambient light serves as the light source for the reflective display device 100, wherein the ambient light can be reflected by the light-reflecting layer 140 to form light for displaying an image (hereinafter, the light reflected by the reflective layer for displaying an image is simply referred to as image display light). Specifically, in Figure 1 In this process, external light can enter from the side of the substrate 110 opposite to the light-reflecting layer 140 (i.e., Figure 1 Light enters the reflective display device 100 from the upper side (as shown). Then, the light entering the reflective display device 100 sequentially passes through the refractive index matching layer 120, the transparent conductive layer 130, and the display medium layer, and is reflected by the light-reflecting layer 140 to form display light. The display light then sequentially passes through the display medium layer, the transparent conductive layer 130, the refractive index matching layer 120, and the substrate 110, and finally exits the reflective display device 100. It should be noted that since the light transmittance of the display medium layer is adjusted according to the electrical signal (e.g., grayscale signal) received by the electrode in the corresponding sub-pixel, the display light exiting the reflective display device 100 will have a luminance corresponding to the electrical signal (e.g., grayscale signal) received by the electrode in the corresponding sub-pixel due to the influence of the light transmittance of the display medium layer in the corresponding sub-pixel, thus enabling image display.

[0035] The reflective display device 100 may also include any suitable film layers and / or structures as needed. For example, in some embodiments, the reflective display device 100 may also include optical film layers, such as anti-reflective films, brightness enhancement films, light scattering layers, wave plates, polarizers, or other suitable optical film layers, which may be disposed in suitable positions according to their respective needs. For example, optical film layers (e.g., polarizers, light scattering layers, wave plates) may be disposed on the side of the substrate 110 (first substrate) opposite to the light-reflecting layer 140, but are not limited thereto.

[0036] For example, in some embodiments, the reflective display device 100 may further include an alignment film for aligning the display medium layer, wherein the alignment film may be disposed between the substrate 110 and the display medium layer and / or between another substrate and the display medium layer. The alignment film may include any material suitable for alignment, for example, but not limited to polyimide (PI).

[0037] For example, in some embodiments, the reflective display device 100 may further include a plurality of spacers disposed between substrate 110 and another substrate, wherein the spacers are used to separate substrate 110 from the other substrate and to create a gap between substrate 110 and the other substrate so that a display dielectric layer can be disposed in the gap between substrate 110 and the other substrate. The spacers may include any suitable insulating material, such as photoresist, resin, other suitable insulating materials or combinations thereof, but are not limited thereto.

[0038] In this invention, the thickness of the transparent conductive layer 130, the number of film layers in the refractive index matching layer 120, the material of the refractive index matching layer 120, and the thickness of the refractive index matching layer 120 can be designed according to the principles of thin-film optics. This ensures that the reflective display device 100 has an appropriate and desirable background color, and that the structure formed by the transparent conductive layer 130 and the refractive index matching layer 120 has an appropriate and desirable light transmittance. It should be noted that when external light illuminates the reflective display device 100, the transparent conductive layer 130 and / or the refractive index matching layer 120 reflect a portion of the external light to form reflected light. The color of this reflected light has the effect of adjusting the background color of the reflective display device 100, and this reflected light is different from the screen display light of the reflective display device 100. Furthermore, for ease of explanation, the structure formed by the refractive index matching layer 120 and the transparent conductive layer 130 will be referred to below as the background color adjustment structure CA (e.g., Figure 1 (As shown). In the following text, the reflected light caused by the background color adjustment structure CA will be referred to as background color adjustment light.

[0039] It should be noted that since the thickness of the transparent conductive layer 130 and the refractive index matching layer 120 are designed based on the principles of thin film optics, the thickness of each film layer in the transparent conductive layer 130 and the refractive index matching layer 120 can be less than or equal to 5000 Å (angtze, 10-10 meters (m)), but is not limited to this.

[0040] Please refer to Figure 2 and Figure 3 And at the same time refer to Figure 1 , Figure 2 The image shows the chromaticity diagram of the reflected light from the transparent conductive layer at different thicknesses according to the CIE L*a*b* color model, as an embodiment of the present invention. Figure 3 The diagram shown illustrates the relationship between the thickness of the transparent conductive layer and its light reflectivity according to an embodiment of the present invention. Figure 2 and Figure 3 The thickness of the transparent conductive layer 130 shown ranges from 100 Å (angtze, 10-10 meters (m)) to 1700 Å. Figure 2 and Figure 3 The optical properties of the transparent conductive layer 130 and the color of the reflected light reflected by the transparent conductive layer 130 are illustrated using an example of a transparent conductive layer 130 formed of indium tin oxide. However, the material, optical properties, and color of the reflected light of the transparent conductive layer 130 of the present invention are not limited thereto. It should be noted that, according to the CIE L*a*b* color model, a* represents the color position between red (a*>0) and green (a*<0), and b* represents the color position between yellow (b*>0) and blue (b*<0).

[0041] like Figure 2 As shown, the color of the reflected light from the transparent conductive layer 130 varies depending on the thickness of the transparent conductive layer 130. According to... Figure 2 The thickness range of the transparent conductive layer 130, the a* of the reflected light reflected by the transparent conductive layer 130 can be -5 to 15, and the b* can be -25 to 15, but is not limited thereto. For example, in Figure 2 In this context, when the thickness of the transparent conductive layer 130 is greater than or equal to 750 Å and less than or equal to 850 Å (i.e., 750 Å ≤ thickness ≤ 850 Å), the reflected light from the transparent conductive layer 130 has a greenish tint (e.g., a* < 0 and |a*| > |b*|), but this is not a limitation. For example, in... Figure 2 In this context, when the thickness of the transparent conductive layer 130 is greater than or equal to 1000 Å and less than 1200 Å (i.e., 1000 Å ≤ thickness < 1200 Å), the reflected light from the transparent conductive layer 130 appears yellowish (e.g., b*>0 and |b*| > |a*|), but this is not a limitation. For example, in... Figure 2In this context, when the thickness of the transparent conductive layer 130 is greater than 1200 Å and less than or equal to 1350 Å (i.e., 1200 Å < thickness ≤ 1350 Å), the reflected light from the transparent conductive layer 130 is reddish (e.g., a*>0 and |a*| > |b*|), but this is not a limitation. For example, in... Figure 2 In the case where the thickness of the transparent conductive layer 130 is greater than or equal to 1500 Å and less than or equal to 1700 Å (i.e., 1500 Å ≤ thickness ≤ 1700 Å), the color of the reflected light reflected by the transparent conductive layer 130 is bluish (e.g., b* < 0 and |b*| > |a*|), but is not limited to this.

[0042] like Figure 3 As shown, the light reflectivity of the transparent conductive layer 130 varies with its thickness. Specifically, when the light reflectivity increases, the light transmittance decreases, and vice versa. For example, in... Figure 3 In this context, when the thickness of the transparent conductive layer 130 is greater than or equal to 500 Å and less than or equal to 850 Å (i.e., 500 Å ≤ thickness ≤ 850 Å), the transparent conductive layer 130 exhibits high light reflectivity and low light transmittance (however, the light transmittance is still higher than the light reflectivity), but this is not a limitation. For example, in... Figure 3 In the case where the thickness of the transparent conductive layer 130 is greater than or equal to 1200 Å and less than or equal to 1500 Å (i.e., 1200 Å ≤ thickness ≤ 1500 Å), the transparent conductive layer 130 has a low light reflectivity and a high light transmittance, but is not limited thereto.

[0043] The following describes three cases: a background color adjustment structure CA containing a transparent conductive layer 130 with low light transmittance (high light reflectance); a background color adjustment structure CA containing a transparent conductive layer 130 with high light transmittance; and a background color adjustment structure CA containing a transparent conductive layer 130 with intermediate light transmittance (light transmittance between high and low light transmittance). For example (e.g.) Figure 3 As shown below, when the transparent conductive layer 130 has low light transmittance (high light reflectance), the thickness of the transparent conductive layer 130 may be 700 Å ± 5% (i.e., the thickness of the transparent conductive layer 130 is greater than or equal to 665 Å and less than or equal to 735 Å), but is not limited thereto. For example (e.g.) Figure 3 As shown below, when the transparent conductive layer 130 has high light transmittance, the thickness of the transparent conductive layer 130 may be 1200 Å ± 5% (i.e., the thickness of the transparent conductive layer 130 is greater than or equal to 1140 Å and less than or equal to 1260 Å), but is not limited thereto. For example (e.g.) Figure 3As shown below, when the transparent conductive layer 130 has intermediate light transmittance, the thickness of the transparent conductive layer 130 may be 1000 Å ± 5% (i.e., the thickness of the transparent conductive layer 130 is greater than or equal to 950 Å and less than or equal to 1050 Å), but is not limited thereto.

[0044] Tables 1 to 9 below illustrate the optical characteristics of the background color adjustment structure CA in these three cases, as well as the color of the background color adjustment light caused by the background color adjustment structure CA. It should be noted that although Tables 1 to 9 illustrate embodiments with a thickness of 700 Å, 1000 Å, and 1200 Å for the transparent conductive layer 130 of the background color adjustment structure CA, the background color adjustment structure CA with a thickness of 700 Å ± 5% has similar optical properties and the resulting background color adjustment light color to the transparent conductive layer 130 with a thickness of 700 Å, the transparent conductive layer 130 with a thickness of 1000 Å ± 5% has similar optical properties and the resulting background color adjustment light color to the transparent conductive layer 130 with a thickness of 1000 Å, and the transparent conductive layer 130 with a thickness of 1200 Å ± 5% has similar optical properties and the resulting background color adjustment light color to the transparent conductive layer 130 with a thickness of 1200 Å.

[0045] [Table 1] Relationship between various thicknesses of silicon dioxide (SiO2) and niobium pentoxide (Nb2O5) in the refractive index matching layer 120 and the light transmittance of the background color adjustment structure CA, which includes a transparent conductive layer 130 with low light transmittance (high light reflectance).

[0046]

[0047] [Table 2] Relationship between various thicknesses of silicon dioxide (SiO2) and niobium pentoxide (Nb2O5) in the refractive index matching layer 120 and the a* of the background color adjustment light caused by the background color adjustment structure CA, which includes a transparent conductive layer 130 with low light transmittance (high light reflectance).

[0048]

[0049] [Table 3] Relationship between various thicknesses of silicon dioxide (SiO2) and niobium pentoxide (Nb2O5) in the refractive index matching layer 120 and the b* of the background color adjustment light caused by the background color adjustment structure CA, which includes a transparent conductive layer 130 with low light transmittance (high light reflectance).

[0050]

[0051] [Table 4] Relationship between various thicknesses of silicon dioxide (SiO2) and niobium pentoxide (Nb2O5) in the refractive index matching layer 120 and the light transmittance of the background color adjustment structure CA, which includes a transparent conductive layer 130 with intermediate light transmittance.

[0052]

[0053] [Table 5] Relationship between the various thicknesses of silicon dioxide (SiO2) and niobium pentoxide (Nb2O5) in the refractive index matching layer 120 and the a* of the background color adjustment light caused by the background color adjustment structure CA, which includes a transparent conductive layer 130 with intermediate light transmittance.

[0054]

[0055] [Table 6] Relationship between the various thicknesses of silicon dioxide (SiO2) and niobium pentoxide (Nb2O5) in the refractive index matching layer 120 and the b* of the background color adjustment light caused by the background color adjustment structure CA, which includes a transparent conductive layer 130 with intermediate light transmittance.

[0056]

[0057] [Table 7] Relationship between various thicknesses of silicon dioxide (SiO2) and niobium pentoxide (Nb2O5) in the refractive index matching layer 120 and the light transmittance of the background color adjustment structure CA, which includes a transparent conductive layer 130 with high light transmittance.

[0058]

[0059] [Table 8] Relationship between various thicknesses of silicon dioxide (SiO2) and niobium pentoxide (Nb2O5) in the refractive index matching layer 120 and the a* of the background color adjustment light caused by the background color adjustment structure CA, which includes a transparent conductive layer 130 with high light transmittance.

[0060]

[0061] [Table 9] Relationship between various thicknesses of silicon dioxide (SiO2) and niobium pentoxide (Nb2O5) in the refractive index matching layer 120 and the b* of the background color adjustment light caused by the background color adjustment structure CA, which includes a transparent conductive layer 130 with high light transmittance.

[0062]

[0063] In this invention, according to the CIE L*a*b* color model, a suitable and desirable background color adjustment light (reflected light caused by the background color adjustment structure CA formed by the refractive index matching layer 120 and the transparent conductive layer 130) can satisfy one of the following conditions (a) to (d): (a) the background color adjustment light has a b* greater than 5, and the background color adjustment light has a a* greater than or equal to -5 and less than or equal to 5 (i.e., b*>5, -5 ≤ a* ≤ 5), making the background color adjustment light yellowish; (b) the background color adjustment light has a b* less than -5, and the background color adjustment light has a a* greater than or equal to -5 and less than or equal to 5 (i.e., b*<-5, -5 ≤ a* ≤ 5), making the background color adjustment light bluish; (c) the background color adjustment light has a a* greater than 5, and the background color adjustment light has a b* greater than or equal to -5 and less than or equal to 5 (i.e., a*>5, -5 ≤ b* ≤ 5). 5) The background color adjustment light is reddish; (d) The a* of the background color adjustment light is less than -5, and the b* of the background color adjustment light is greater than or equal to -5 and less than or equal to 5 (i.e., a* < -5, -5 ≤ b* ≤ 5), making the background color adjustment light greenish. When the background color adjustment light meets one of these conditions, the reflective display device 100 can have an appropriate background color to improve the display effect.

[0064] like Figure 1 As shown, the refractive index matching layer 120 in this embodiment is exemplified by a multilayer structure comprising niobium oxide and silicon oxide. More specifically, the refractive index matching layer 120 in this embodiment may be a multilayer structure comprising a first matching layer 122 and a second matching layer 124. The first matching layer 122 may be disposed between the substrate 110 and the second matching layer 124, and the second matching layer 124 may be disposed between the first matching layer 122 and the transparent conductive layer 130. The first matching layer 122 may include niobium oxide (e.g., niobium pentoxide (Nb₂O₅)), and the second matching layer 124 may include silicon oxide (e.g., silicon dioxide (SiO₂)). For example, the first matching layer 122 may directly contact the substrate 110, and the second matching layer 124 may directly contact the transparent conductive layer 130, but this is not a limitation.

[0065] According to Tables 2, 3, 5, 6, 8, and 9, when the b* of the background color adjustment light is greater than 5, and the a* of the background color adjustment light is greater than or equal to -5 and less than or equal to 5 (i.e., condition (a)), the thicknesses of the first matching layer 122, the second matching layer 124, and the transparent conductive layer 130 can satisfy one of the following conditions (a-1) to (a-2): (a-1) The thickness of the transparent conductive layer 130 is greater than or equal to 665 Å and less than or equal to 735 Å, the thickness of the first matching layer 122 is greater than or equal to 100 Å and less than or equal to 200 Å, and the thickness of the second matching layer 124 is greater than or equal to 100 Å and less than or equal to 200 Å (i.e., 665 Å ≤ thickness of transparent conductive layer 130 ≤ 735 Å, 100 Å ≤ thickness of first matching layer 122 ≤ 200 Å, 100 Å ≤ thickness of second matching layer 124 ≤ 200 Å). (a-2) The thickness of the transparent conductive layer 130 is greater than or equal to 950 Å and less than or equal to 1050 Å, the thickness of the first matching layer 122 is greater than 0 Å and less than 100 Å, and the thickness of the second matching layer 124 is greater than 0 Å and less than 100 Å (i.e., 950 Å ≤ thickness of transparent conductive layer 130 ≤ 1050 Å, 0 Å < thickness of first matching layer 122 < 100 Å, 0 Å < thickness of second matching layer 124 < 100 Å), but not limited to these. Therefore, according to the film layer design, the background color adjustment light can be made to appear yellowish.

[0066] According to Tables 2, 3, 5, 6, 8, and 9, when the b* of the background color adjustment light is less than -5, and the a* of the background color adjustment light is greater than or equal to -5 and less than or equal to 5 (i.e., condition (b)), the thicknesses of the first matching layer 122, the second matching layer 124, and the transparent conductive layer 130 can satisfy one of the following conditions (b-1) to (b-3): (b-1) The thickness of the transparent conductive layer 130 is greater than or equal to 665 Å and less than or equal to 735 Å, the thickness of the first matching layer 122 is greater than or equal to 380 Å and less than or equal to 420 Å (i.e., within the range of 400 Å ± 5%), and the thickness of the second matching layer 124 is greater than or equal to 400 Å and less than or equal to 500 Å (i.e., 665 Å ≤ thickness of transparent conductive layer 130 ≤ 735 Å, 380 Å ≤ thickness of first matching layer 122 ≤ 420 Å, 400 Å ≤ The thickness of the second matching layer 124 is ≤ 500 Å); (b-2) The thickness of the transparent conductive layer 130 is greater than or equal to 950 Å and less than or equal to 1050 Å, the thickness of the first matching layer 122 is greater than or equal to 300 Å and less than or equal to 400 Å, and the thickness of the second matching layer 124 is greater than or equal to 200 Å and less than or equal to 300 Å (i.e., 950 Å ≤ the thickness of the transparent conductive layer 130 ≤ 1050 Å, 300 Å ≤ the thickness of the first matching layer 122 ≤ 400 Å, and 200 Å ≤ the thickness of the second matching layer 124 ≤ 300 Å); (b-3) The thickness of the transparent conductive layer 130 is greater than or equal to 1140 Å and less than or equal to 1260 Å, the thickness of the first matching layer 122 is greater than or equal to 190 Å and less than or equal to 210 Å (i.e., within the range of 200 Å ± 5%), and the thickness of the second matching layer 124 is greater than or equal to 200 Å and less than or equal to 300 Å (i.e., 1140 Å ≤ thickness of transparent conductive layer 130 ≤ 1260 Å, 190 Å ≤ thickness of first matching layer 122 ≤ 210 Å, 200 Å ≤ thickness of second matching layer 124 ≤ 300 Å), but not limited to these limits. Therefore, according to the film layer design, the background color adjustment light can be made to have a bluish tint.

[0067] According to Tables 2, 3, 5, 6, 8, and 9, when the a* of the background color adjustment light is greater than 5, and the b* of the background color adjustment light is greater than or equal to -5 and less than or equal to 5 (i.e., condition (c)), the thickness of the first matching layer 122, the thickness of the second matching layer 124, and the thickness of the transparent conductive layer 130 can satisfy one of the following conditions (c-1) to (c-3): (c-1) The thickness of the transparent conductive layer 130 is greater than or equal to 665 Å and less than or equal to 735 Å, the thickness of the first matching layer 122 is greater than or equal to 190 Å and less than or equal to 210 Å (i.e., within the range of 200 Å ± 5%), and the thickness of the second matching layer 124 is greater than or equal to 285 Å and less than or equal to 315 Å (i.e., within the range of 300 Å ± 5%) (i.e., 665 Å ≤ the thickness of the transparent conductive layer 130 ≤ 735 Å, 190 Å ≤ the thickness of the first matching layer 122 ≤ 735 Å). (c-2) The thickness of the transparent conductive layer 130 is greater than or equal to 665 Å and less than or equal to 735 Å, the thickness of the first matching layer 122 is greater than or equal to 285 Å and less than or equal to 315 Å (i.e., within the range of 300 Å ± 5%), and the thickness of the second matching layer 124 is greater than or equal to 95 Å and less than or equal to 105 Å (i.e., within the range of 100 Å ± 5%) (i.e., 665 Å ≤ the thickness of the transparent conductive layer 130 ≤ 735 Å, 285 Å ≤ the thickness of the first matching layer 122 ≤ 315 Å, 95 Å ≤ the thickness of the second matching layer 124 ≤ 315 Å). (c-3) The thickness of the transparent conductive layer 130 is greater than or equal to 950 Å and less than or equal to 1050 Å, the thickness of the first matching layer 122 is greater than or equal to 95 Å and less than or equal to 105 Å (i.e., within the range of 100 Å ± 5%), and the thickness of the second matching layer 124 is greater than or equal to 200 Å and less than or equal to 300 Å (i.e., 950 Å ≤ thickness of transparent conductive layer 130 ≤ 1050 Å, 95 Å ≤ thickness of first matching layer 122 ≤ 105 Å, 200 Å ≤ thickness of second matching layer 124 ≤ 300 Å), but not limited thereto. Therefore, according to the film layer design, the background color adjustment light can be made to appear reddish.

[0068] According to Tables 2, 3, 5, 6, 8, and 9, when the a* of the background color adjustment light is less than -5, and the b* of the background color adjustment light is greater than or equal to -5 and less than or equal to 5 (i.e., condition (d)), the thicknesses of the first matching layer 122, the second matching layer 124, and the transparent conductive layer 130 can satisfy the following conditions (d-1): (d-1) The thickness of the transparent conductive layer 130 is greater than or equal to 1140 Å and less than or equal to 1260 Å, the thickness of the first matching layer 122 is greater than or equal to 300 Å and less than or equal to 400 Å, and the thickness of the second matching layer 124 is greater than or equal to 475 Å and less than or equal to 525 Å (i.e., within the range of 500 Å ± 5%) (i.e., 1140 Å ≤ thickness of transparent conductive layer 130 ≤ 1260 Å, 300 Å ≤ thickness of first matching layer 122 ≤ 400 Å, 475 Å ≤ The thickness of the second matching layer 124 is ≤ 525 Å, but not limited to this. Therefore, depending on the film design, the background color adjustment light can be made to appear greenish.

[0069] In some embodiments, the light transmittance of the background color adjustment structure CA can also be selectively greater than or equal to 85% (i.e., the transmittance of light through the refractive index matching layer 120 and the transparent conductive layer 130 can be selectively greater than or equal to 85%) to improve the utilization rate of light.

[0070] For example, according to Tables 1, 4, and 7, when the light transmittance of the background color adjustment structure CA is greater than or equal to 85%, the thicknesses of the first matching layer 122, the second matching layer 124, and the transparent conductive layer 130 can satisfy one of the following conditions (e-1) to (e-3): (e-1) The thickness of the transparent conductive layer 130 is greater than or equal to 665 Å and less than or equal to 735 Å, the thickness of the first matching layer 122 is greater than or equal to 100 Å and less than or equal to 300 Å, and the thickness of the second matching layer 124 is greater than or equal to 200 Å and less than or equal to 500 Å (i.e., 665 Å ≤ thickness of transparent conductive layer 130 ≤ 735 Å, 100 Å ≤ thickness of first matching layer 122 ≤ 300 Å, 200 Å ≤ thickness of second matching layer 124 ≤ 500 Å); (e-2) The thickness of the transparent conductive layer 130 is greater than or equal to 950 Å and less than or equal to 1050 Å, the thickness of the first matching layer 122 is greater than or equal to 100 Å and less than or equal to 300 Å, and the thickness of the second matching layer 124 is greater than 0 Å and less than or equal to 300 Å (i.e., 950 Å ≤ thickness of transparent conductive layer 130 ≤ 1050 Å, 100 Å ≤ thickness of first matching layer 122 ≤ 300 Å, 0 < thickness of second matching layer 124 ≤ 300 Å); (e-3) The thickness of the transparent conductive layer 130 is greater than or equal to 1140 Å and less than or equal to 1260 Å, the thickness of the first matching layer 122 is greater than 0 Å and less than or equal to 200 Å, and the thickness of the second matching layer 124 is greater than 0 Å and less than or equal to 500 Å (i.e., 1140 Å ≤ thickness of transparent conductive layer 130 ≤ 1260 Å, 0 < thickness of first matching layer 122 ≤ 1260 Å, 0 < thickness of first matching layer 122 ≤ 1260 Å, 0 < thickness of first matching layer 122 ≤ 1260 Å, 0 < thickness of first matching layer 124 ... 200Å, 0 < the thickness of the second matching layer 124 ≤ 500Å), but not limited to this.

[0071] Accordingly, based on the design of the background color adjustment structure CA described above, the reflective display device 100 can have an appropriate background color according to requirements (e.g., the image to be displayed, the usage environment of the reflective display device 100, and / or other requirements), and the light utilization rate can be improved by increasing the light transmittance of the background color adjustment structure CA.

[0072] Furthermore, the material of the light-reflecting layer 140 also affects the color of the reflected light. Therefore, the material of the light-reflecting layer 140 can be selected according to requirements, so that the reflective display device 100 can produce a background color of appropriate color. For example... Figure 4 As shown, it is a schematic diagram illustrating the relationship between the wavelength of reflected light and the corresponding light reflectivity of the light-reflecting layer 140 according to an embodiment of the present invention. For example, according to Figure 4When the material of the light-reflecting layer 140 is silver, because the light reflectivity of silver in the short-wavelength band is significantly lower than that in other bands, the reflected light from the silver-material light-reflecting layer 140 has a yellowish tint (e.g., b* is 2.15). In other words, when the reflective display device 100 includes a silver-material light-reflecting layer 140, the reflected light is relatively yellowish. Therefore, by appropriately selecting the background color adjustment structure CA, for example, selecting a background color adjustment structure CA that adjusts the light to a bluish tint, the background color of the reflective display device 100 can be made closer to white. For example, according to... Figure 4 When the material of the light reflective layer 140 is aluminum, since the light reflectivity of aluminum does not have a significant difference across different wavelengths, the reflected light from the aluminum light reflective layer 140 is whitish (e.g., b* is 0.45). In other words, when the reflective display device 100 includes the aluminum light reflective layer 140, the reflected light is relatively whitish. Therefore, by appropriately selecting the background color adjustment structure CA, the background color of the reflective display device 100 can be made consistent with the background color adjustment light caused by the background color adjustment structure CA.

[0073] The reflective display device of the present invention is not limited to the above embodiments. Other embodiments will continue to be disclosed below. However, in order to simplify the description and highlight the differences between the embodiments and the above embodiments, the same reference numerals are used to refer to the same elements below, and repeated parts will not be described again.

[0074] Please refer to Figure 5 , Figure 5 The diagram shown is a cross-sectional view of a reflective display device according to a second embodiment of the present invention. Figure 5 As shown, the difference between this embodiment and the first embodiment is that the refractive index matching layer 120 of the reflective display device 200 in this embodiment is a single-layer structure. For example, the refractive index matching layer 120 may be a single-layer structure including niobium oxide or a single-layer structure including silicon oxide.

[0075] When the refractive index matching layer 120 is a single-layer structure including niobium oxide, according to Tables 1, 4, and 7, when the light transmittance of the background color adjustment structure CA is greater than or equal to 85%, the thickness of the refractive index matching layer 120 and the thickness of the transparent conductive layer 130 can satisfy one of the following conditions (f-1) to (f-2): (f-1) The thickness of the transparent conductive layer 130 is greater than or equal to 950 Å and less than or equal to 1050 Å, and the thickness of the refractive index matching layer 120 is greater than or equal to 100 Å and less than or equal to 300 Å (i.e., 950 Å ≤ the thickness of the transparent conductive layer 130 ≤ 1050 Å, 100 Å ≤ the thickness of the refractive index matching layer 120 ≤ 300 Å); (f-2) The thickness of the transparent conductive layer 130 is greater than or equal to 1140 Å and less than or equal to 1260 Å, and the thickness of the refractive index matching layer 120 is greater than 0 Å and less than or equal to 200 Å (i.e., 1140 Å). The thickness of the transparent conductive layer 130 is ≤ 1260 Å, and the thickness of the refractive index matching layer 120 is ≤ 200 Å, but not limited thereto.

[0076] When the refractive index matching layer 120 is a single-layer structure including silicon oxide, according to Tables 2, 3, 5, 6, 8, and 9, when the b* of the background color adjustment light is greater than 5, and the a* of the background color adjustment light is greater than or equal to -5 and less than or equal to 5 (i.e., condition (a)), the thickness of the transparent conductive layer 130 can be greater than or equal to 950 Å and less than or equal to 1050 Å, and the thickness of the refractive index matching layer 120 can be greater than 0 Å and less than 400 Å (i.e., 950 Å ≤ thickness of transparent conductive layer 130 ≤ 1050 Å, 0 Å < thickness of refractive index matching layer 120 < 400 Å), but is not limited thereto. Therefore, according to the film layer design, the background color adjustment light can be made to appear yellowish.

[0077] When the refractive index matching layer 120 is a single-layer structure including silicon oxide, according to Tables 2, 3, 5, 6, 8, and 9, when the a* of the background color adjustment light is greater than 5, and the b* of the background color adjustment light is greater than or equal to -5 and less than or equal to 5 (i.e., condition (c)), the thickness of the transparent conductive layer 130 can be greater than or equal to 1140 Å and less than or equal to 1260 Å, and the thickness of the refractive index matching layer 120 can be greater than or equal to 100 Å and less than or equal to 200 Å (i.e., 1140 Å ≤ thickness of transparent conductive layer 130 ≤ 1260 Å, 100 Å ≤ thickness of refractive index matching layer 120 ≤ 200 Å), but is not limited thereto. Therefore, according to the film layer design, the background color adjustment light can be made to appear reddish.

[0078] When the refractive index matching layer 120 is a single-layer structure including silicon oxide, according to Tables 1, 4, and 7, when the light transmittance of the background color adjustment structure CA is greater than or equal to 85%, the thickness of the refractive index matching layer 120 and the thickness of the transparent conductive layer 130 can satisfy one of the following conditions (g-1) to (g-2): (g-1) The thickness of the transparent conductive layer 130 is greater than or equal to 950 Å and less than or equal to 1050 Å, and the thickness of the refractive index matching layer 120 is greater than or equal to 200 Å and less than or equal to 500 Å (i.e., 950 Å ≤ the thickness of the transparent conductive layer 130 ≤ 1050 Å, 200 Å ≤ the thickness of the refractive index matching layer 120 ≤ 500 Å); (g-2) The thickness of the transparent conductive layer 130 is greater than or equal to 1140 Å and less than or equal to 1260 Å, and the thickness of the refractive index matching layer 120 is greater than 0 Å and less than or equal to 500 Å (i.e., 1140 Å). The thickness of the transparent conductive layer 130 is ≤ 1260 Å, and the thickness of the refractive index matching layer 120 is ≤ 500 Å, but not limited thereto.

[0079] Please refer to Figure 6 , Figure 6 The diagram shown is a cross-sectional view of a reflective display device according to a third embodiment of the present invention. Figure 6 As shown, the difference between this embodiment and the first embodiment is that the reflective display device 300 in this embodiment further includes a color conversion layer 312, disposed between the refractive index matching layer 120 and the substrate 110, to convert or filter light into different colors of light. Examples of materials that can be used for the color conversion layer 312 include color filters, quantum dot (QD) materials, fluorescent materials, phosphorescent materials, other suitable materials, or any combination thereof. For example, the refractive index matching layer 120 may directly contact the color conversion layer 312, but this is not a limitation. Since the reflective display device 300 in this embodiment is a color display, the color conversion layer 312 may include multiple color conversion units (e.g., three color conversion units 312a, 312b, and 312c), each located in a sub-pixel of a different color (e.g., color conversion units 312a, 312b, and 312c are located in a green sub-pixel, a red sub-pixel, and a blue sub-pixel, respectively), to convert light into the corresponding color, but this is not a limitation.

[0080] Please refer to Figure 7 , Figure 7 The diagram shown is a cross-sectional view of a reflective display device according to a fourth embodiment of the present invention. Figure 7As shown, the difference between this embodiment and the first embodiment is that the reflective display device 400 in this embodiment further includes a cover layer 410 disposed between the refractive index matching layer 120 and the substrate 110. For example, the cover layer 410 may include any suitable transparent insulating material, such as a transparent organic insulating material, but is not limited thereto. For example, the refractive index matching layer 120 may directly contact the cover layer 410, but is not limited thereto.

[0081] Please refer to Figure 8 , Figure 8 The image shown is a cross-sectional schematic diagram of a reflective display device according to a fifth embodiment of the present invention. Figure 8 As shown, the difference between this embodiment and the first embodiment is that the reflective display device 500 in this embodiment further includes a color conversion layer 312 and a cover layer 410, disposed between the refractive index matching layer 120 and the substrate 110. For example, in Figure 8 In this configuration, the color conversion layer 312 is disposed between the substrate 110 and the capping layer 410, and the capping layer 410 is disposed between the refractive index matching layer 120 and the color conversion layer 312, but is not limited thereto. For example, the refractive index matching layer 120 may directly contact the capping layer 410, but is not limited thereto.

[0082] In summary, according to the design of the refractive index matching layer and the transparent conductive layer of the present invention, the reflective display device can have an appropriate background color as needed, and the light utilization rate can be improved by increasing the light transmittance of the background color adjustment structure.

[0083] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A reflective display device, characterized in that, include: One substrate; A refractive index matching layer is disposed on the substrate; A transparent conductive layer is disposed on the refractive index matching layer; A light-reflecting layer is disposed on the opposite side of the transparent conductive layer relative to the substrate. The light reflected by the light-reflecting layer is used to display an image, and the light-reflecting layer includes silver. A display medium layer is disposed between the transparent conductive layer and the light reflective layer, wherein the transparent conductive layer is disposed between the display medium layer and the refractive index matching layer; According to the CIE L*a*b* color model, the b* of the reflected light caused by the refractive index matching layer and the transparent conductive layer is less than -5, and the a* of the reflected light is greater than or equal to -5 and less than or equal to 5. The refractive index matching layer includes a first matching layer and a second matching layer. The first matching layer is disposed between the substrate and the second matching layer, and the second matching layer is disposed between the first matching layer and the transparent conductive layer. The first matching layer includes niobium oxide, and the second matching layer includes silicon oxide. The thicknesses of the first matching layer, the second matching layer, and the transparent conductive layer satisfy one of the following conditions (b-1) to (b-3): (b-1) The thickness of the transparent conductive layer is greater than or equal to 665 Å and less than or equal to 735 Å, the thickness of the first matching layer is greater than or equal to 380 Å and less than or equal to 420 Å, and the thickness of the second matching layer is greater than or equal to 400 Å and less than or equal to 500 Å. (b-2) The thickness of the transparent conductive layer is greater than or equal to 950 Å and less than or equal to 1050 Å, the thickness of the first matching layer is greater than or equal to 300 Å and less than or equal to 400 Å, and the thickness of the second matching layer is greater than or equal to 200 Å and less than or equal to 300 Å. (b-3) The thickness of the transparent conductive layer is greater than or equal to 1140 Å and less than or equal to 1260 Å, the thickness of the first matching layer is greater than or equal to 190 Å and less than or equal to 210 Å, and the thickness of the second matching layer is greater than or equal to 200 Å and less than or equal to 300 Å.

2. The reflective display device as described in claim 1, characterized in that, The transmittance of light through the refractive index matching layer and the transparent conductive layer is greater than or equal to 85%.

3. The reflective display device as described in claim 1, characterized in that, The transparent conductive layer comprises indium tin oxide.

4. The reflective display device as described in claim 1, characterized in that, It also includes a color conversion layer disposed between the refractive index matching layer and the substrate.

5. The reflective display device as described in claim 1, characterized in that, It also includes a cover layer disposed between the refractive index matching layer and the substrate.

Images