Display device including covering layer and covering layer for display device

Abstract

The invention relates to a display device having a cover layer and a cover layer for a display device. The capping layer includes: a sapphire substrate; a first capping layer disposed on the sapphire substrate, the first capping layer including MgF2, the first capping layer having a thickness in a range of about 16 nm to about 26 nm; a second capping layer disposed on the first capping layer, the second capping layer including Si9Al2O10, the second capping layer having a thickness in a range of about 45 nm to about 70 nm; and a third capping layer disposed on the second capping layer, the third capping layer including a perfluoropolyether (PEPE), the third capping layer having a thickness in a range of about 10 nm to about 45 nm.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the priority of Korean Patent Application No. 10-2023-0096942 filed in the Korean Intellectual Property Office on July 25, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a display device having a cover layer and a cover layer for a display device. Background Art

[0004] As information technology develops, the importance of display devices as a connection medium between users and information increases.

[0005] A structure for improving external visibility may be required in a display device. For example, it may be necessary to control reflection of external light to improve external visibility. Summary of the invention

[0006] Embodiments provide a display device having a cover layer and a cover layer for a display device in which reflection of external light may be controlled, so that visibility may be improved.

[0007] Embodiments also provide a display device having a cover layer and the cover layer in which excellent color shift characteristics (ie, ΔE or reflection color sense) can be provided, so that the reliability of display quality can be improved.

[0008] According to aspects of the present disclosure, a cover layer may be provided. The cover layer may include: a sapphire substrate; a first cover layer disposed on the sapphire substrate, the first cover layer including MgF 2 The first capping layer has a thickness in the range of about 16 nm to about 26 nm; a second capping layer is disposed on the first capping layer, the second capping layer includes Si 9 Al 2 O 10 , the second covering layer has a thickness in the range of about 45nm to about 70nm; and a third covering layer, disposed on the second covering layer, the third covering layer includes perfluoropolyether (PEPE), and the third covering layer has a thickness in the range of about 10nm to about 45nm.

[0009] A surface of the first cover layer may contact the sapphire substrate, another surface of the first cover layer may contact the surface of the second cover layer, and another surface of the second cover layer may contact the surface of the third cover layer.

[0010] The first capping layer may include MgF 2 of the crystal structure.

[0011] The refractive index of the first cover layer may be in the range of about 1.24 to about 1.52.

[0012] The thickness of the first capping layer may be in the range of about 18 nm to about 24 nm.

[0013] The second cover layer may couple the first cover layer to the third cover layer.

[0014] The refractive index of the second cover layer may be in the range of about 1.33 to about 1.63.

[0015] The thickness of the second capping layer may be in the range of about 52 nm to about 64 nm.

[0016] The other surface of the third cover layer may be exposed.

[0017] The refractive index of the third cover layer may be in the range of about 1.05 to about 1.59.

[0018] The thickness of the third capping layer may be in the range of about 32 nm to about 40 nm.

[0019] The refractive index of the sapphire substrate may be about 1.77, the refractive index of the first capping layer may be about 1.38, the refractive index of the second capping layer may be about 1.48, and the refractive index of the third capping layer may be about 1.32.

[0020] According to another aspect of the present disclosure, a display device may be provided, which may include: a light emitting element layer including a light emitting element that emits light; and a cover layer disposed on the light emitting element layer, wherein the cover layer may include: a sapphire substrate; a first cover layer disposed on the sapphire substrate, the first cover layer including MgF 2 The first capping layer has a thickness in the range of about 16 nm to about 26 nm; a second capping layer is disposed on the first capping layer, the second capping layer includes Si 9 Al 2 O 10 , the second covering layer has a thickness in the range of about 45nm to about 70nm; and a third covering layer, disposed on the second covering layer, the third covering layer includes perfluoropolyether (PEPE), and the third covering layer has a thickness in the range of about 10nm to about 45nm.

[0021] The sum of the thicknesses of the first capping layer, the second capping layer, and the third capping layer may be in the range of about 80 nm to about 130 nm.

[0022] The refractive index of the sapphire substrate may be in the range of about 1.60 to about 1.95.

[0023] The cover layer may have a transmittance of at least about 91.2% with respect to light having a wavelength of 550 nm, and may have a reflectance of less than about 8.50% with respect to light having a wavelength of 550 nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the accompanying drawings, dimensions may be exaggerated for clarity of illustration. It will be understood that when an element is referred to as being "between" two elements, it may be the only element between the two elements, or one or more intervening elements may also be present. The same reference numerals represent the same elements throughout.

[0025] Figure 1 is a schematic plan view showing a display device according to an embodiment of the present disclosure.

[0026] Figure 2 is a schematic cross-sectional view showing a display device according to an embodiment of the present disclosure.

[0027] Figure 3 is a schematic cross-sectional view showing a cover layer according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] It will be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, without departing from the teachings of the present disclosure, the "first" element discussed below may also be referred to as the "second" element.

[0029] In the following description, for the purpose of explanation, many specific details are set forth to provide a thorough understanding of various embodiments or implementations of the present invention. As used herein, "embodiment" and "implementation" are interchangeable words, which are non-limiting examples of the devices or methods disclosed herein. However, it is apparent that various embodiments can be practiced without these specific details or with one or more equivalent arrangements. Here, various embodiments do not have to be exclusive and do not limit the present disclosure. For example, the specific shape, configuration and characteristics of an embodiment can be used or implemented in another embodiment.

[0030] Unless otherwise specified, the embodiments shown should be understood to provide features of the present invention. Therefore, unless otherwise specified, the features, components, modules, layers, films, panels, regions and / or aspects of various embodiments, etc. (hereinafter individually or collectively referred to as "elements") can be combined, separated, interchanged and / or rearranged in other ways without departing from the concept of the present invention.

[0031] The use of cross hatching and / or shading in the drawings is generally provided to clarify the boundaries between adjacent elements. Therefore, unless specified, the presence or absence of cross hatching or shading does not convey or indicate any preference or requirement for a particular material, material property, size, ratio, commonality between the elements shown, and / or any other characteristics, attributes, properties, etc. of the elements. In addition, in the drawings, the size and relative size of the elements may be exaggerated for the purpose of clarity and / or description. When the embodiments may be implemented differently, a specific process sequence may be performed differently from the described sequence. For example, two processes described in succession may be performed substantially simultaneously, or in an order opposite to the described sequence. In addition, the same reference numerals and / or reference characters represent the same elements.

[0032] When an element such as a layer is referred to as being "on" another element or layer, "connected to" or "coupled to" another element or layer, it may be directly on, directly connected to or directly coupled to another element or layer, or there may be an intervening element or layer. However, when an element or layer is referred to as being "directly on" another element or layer, "directly connected to" or "directly coupled to" another element or layer, there is no intervening element or layer. For this reason, the term "connection" may refer to a physical connection, an electrical connection, and / or a fluid connection with or without an intervening element. In addition, the X-axis, the Y-axis, and the Z-axis are not limited to three axes such as the x-axis, the y-axis, and the z-axis of a rectangular coordinate system, and may be interpreted in a broader sense. For example, the X-axis, the Y-axis, and the Z-axis may be perpendicular to each other, or may represent different directions that are not perpendicular to each other.

[0033] For the purpose of this disclosure, "at least one of A and B" may be interpreted as only A, only B, or any combination of A and B. In addition, "at least one of X, Y, and Z" and "at least one selected from the group consisting of X, Y, and Z" may be interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0034] For descriptive purposes, spatially relative terms such as "below," "below," "under," "down," "above," "up," "above," "higher," "side" (e.g., as in "sidewall"), etc. may be used herein and thereby describe the relationship of one element to another element(s) as shown in the accompanying drawings. In addition to the orientations described in the accompanying drawings, spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture. For example, if the device in the accompanying drawings is flipped, an element described as being "below" or "below" other elements or features will then be oriented "above" the other elements or features. Thus, the term "below" may encompass both above and below orientations. Additionally, the device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and therefore, the spatially relative descriptors used herein should be interpreted accordingly.

[0035] The terms used herein are used for the purpose of describing specific embodiments and are not intended to be limiting. As used herein, the singular forms "a", "a kind of" and "the" are intended to also include plural forms unless the context clearly indicates otherwise. In addition, when used in this specification, the terms "comprises", "conprising", "includes" and / or "including" specify the existence of stated features, wholes, steps, operations, elements, components and / or groups thereof, but do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof. It should also be noted that, as used herein, the terms "substantially", "about" and other similar terms are used as approximate terms and not as degree terms, and therefore, are used to explain the inherent deviations in the values ​​measured, calculated and / or provided that will be recognized by those of ordinary skill in the art.

[0036] Various embodiments are described herein with reference to cross-sectional illustrations and / or exploded illustrations as schematic illustrations of embodiments and / or intermediate structures. Therefore, variations in the shapes of the illustrations due to, for example, manufacturing techniques and / or tolerances should be expected. Therefore, the embodiments disclosed herein should not necessarily be interpreted as being limited to the shapes of the specifically illustrated regions, but should include deviations in shapes due to, for example, manufacturing. In this way, the regions shown in the accompanying drawings may be schematic in nature, and the shapes of these regions may not reflect the actual shapes of the regions of the device, and therefore, are not necessarily intended to be limiting.

[0037] Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. It will also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and should not be interpreted in an idealized or overly formal sense unless clearly so defined herein.

[0038] The present disclosure generally relates to a display device having a cover layer and a cover layer for a display device. Hereinafter, a display device having a cover layer and a cover layer for a display device according to embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0039] Figure 1 is a schematic plan view showing a display device according to an embodiment of the present disclosure.

[0040] refer to Figure 1 The display device DD may include a base layer BSL and pixels PXL arranged on the base layer BSL. Although not shown in the drawings, the display device DD may further include a driving circuit portion (eg, a scan driver and a data driver), lines, and pads for driving the pixels PXL.

[0041] The display device DD (or base layer BSL) may include a display area DA and a non-display area NDA. The non-display area NDA may mean an area other than the display area DA. The non-display area NDA may surround at least a portion of the display area DA.

[0042] The base layer BSL may form the base surface of the display device DD. The base layer BSL may be a rigid or flexible substrate or film. For example, the base layer BSL may be a rigid substrate made of glass or tempered glass, a flexible substrate (or film) made of a plastic or metal material, or at least one insulating layer. The material and / or properties of the base layer BSL may not be particularly limited. In an embodiment, the base layer BSL may be substantially transparent. The term "substantially transparent" may mean that light can be transmitted with a transmittance (e.g., a predetermined or selectable transmittance) or higher. In an embodiment, the base layer BSL may be translucent or opaque. In addition, in some embodiments, the base layer BSL may include a reflective material.

[0043] The display area DA may mean an area in which the pixels PXL may be disposed. The non-display area NDA may mean an area in which the pixels PXL may not be disposed. Driving circuits, lines, and pads that may be electrically connected to the pixels PXL of the display area DA may be disposed in the non-display area NDA.

[0044] According to an embodiment, the pixel PXL (or the sub-pixel SPX) may be arranged according to a stripe structure, Arrangement structure etc. However, the present disclosure may not be limited thereto, and various embodiments may be applied in the present disclosure.

[0045] According to an embodiment, the pixel PXL (or sub-pixel SPX) may include a first sub-pixel SPX1, a second sub-pixel SPX2, and a third sub-pixel SPX3. Each of the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 may be a sub-pixel. At least one first sub-pixel SPX1, at least one second sub-pixel SPX2, and at least one third sub-pixel SPX3 may constitute a pixel portion capable of emitting light of various colors.

[0046] For example, each of the first sub-pixel SPX1, the second sub-pixel SPX2, and the third sub-pixel SPX3 may emit light of one color. For example, the first sub-pixel SPX1 may be a red pixel that emits red (e.g., the first color) light, the second sub-pixel SPX2 may be a green pixel that emits green (e.g., the second color) light, and the third sub-pixel SPX3 may be a blue pixel that emits blue (e.g., the third color) light. According to an embodiment, the number of the second sub-pixels SPX2 may be greater than the number of the first sub-pixels SPX1 and the number of the third sub-pixels SPX3. However, the colors, kinds, and / or numbers of the first sub-pixels SPX1, the second sub-pixels SPX2, and the third sub-pixels SPX3 that constitute each pixel portion may not be limited to a specific example.

[0047] Figure 2 is a schematic cross-sectional view showing a display device according to an embodiment of the present disclosure.

[0048] refer to Figure 2 , the display device DD may include a pixel circuit layer PCL (eg, a backplane layer), a light emitting element layer LEL, and a cover layer COL.

[0049] The pixel circuit layer PCL may be a layer including a pixel circuit for driving a pixel PXL formed by a light emitting element layer LEL (or a light emitting element included in the light emitting element layer LEL). The pixel circuit layer PCL may include a base layer BSL, a conductive layer for forming a pixel circuit, and an insulating layer disposed on the conductive layer.

[0050] The light emitting element layer LEL may be disposed on the pixel circuit layer PCL. In some embodiments, the light emitting element layer LEL may include a light emitting element. In some embodiments, the light emitting element may include an organic light emitting diode (OLED). In some embodiments, the light emitting element may include an inorganic light emitting element including an inorganic material. In some embodiments, the light emitting element layer LEL may include a liquid crystal display (LCD). However, the present disclosure may not necessarily be limited thereto.

[0051] The cover layer COL may be disposed on the light emitting element layer LEL. The cover layer COL may allow light emitted from the light emitting element layer LEL to be transmitted to the outside through itself to be observed. The cover layer COL may have a coating structure.

[0052] Will refer to it later Figure 3 The cover layer COL according to an embodiment of the present disclosure is described in detail.

[0053] Figure 3 is a schematic cross-sectional view showing a cover layer according to an embodiment of the present disclosure.

[0054] The cover layer COL according to an embodiment of the present disclosure may have a characteristic of reducing reflection of external light.

[0055] According to an embodiment, the cover layer COL may include a sapphire substrate SS and a functional layer on the sapphire substrate SS. For example, the cover layer COL may include a sapphire substrate SS and first, second, and third cover layers CL1, CL2, and CL3 that may be disposed on the sapphire substrate SS.

[0056] In some embodiments, the sapphire substrate SS may form a base of the cover layer COL. For example, the first cover layer CL1, the second cover layer CL2, and the third cover layer CL3 that may be disposed on the sapphire substrate SS may be formed by a physical vapor deposition (PVD) process including sputtering, electron beam evaporation, thermal evaporation, and ion assisted deposition (IAD). However, the present disclosure may not be limited to specific examples.

[0057] In some embodiments, the total thickness of the first cover layer CL1, the second cover layer CL2, and the third cover layer CL3 disposed on the sapphire substrate SS may be in the range of about 80 nm to about 130 nm. For example, the first cover layer CL1, the second cover layer CL2, and the third cover layer CL3, each having a refractive index, may satisfy a thickness range (e.g., a predetermined or selectable thickness range), and therefore, appropriate anti-reflection performance may be achieved. This will be described in detail later.

[0058] In some embodiments, the sapphire substrate SS may be disposed on an uppermost portion (eg, a thin film encapsulation layer, a capping layer, etc.) of the light emitting element layer LEL.

[0059] The sapphire substrate SS may include aluminum oxide (Al x O y ) and includes a crystal structure. Since the sapphire substrate SS has high hardness, the sapphire substrate SS can have high scratch resistance.

[0060] The sapphire substrate SS may have a relatively high refractive index compared to a general glass substrate. The sapphire substrate SS may have the highest refractive index among the layers forming the cover layer COL.

[0061] The sapphire substrate SS may have a substrate refractive index n s . Substrate refractive index n s It may be in the range of about 1.60 to about 1.95. In some embodiments, the substrate refractive index n s It may be about 1.77. However, the present disclosure may not be limited thereto.

[0062] Light emitted from the light emitting element layer LEL may be transmitted through the sapphire substrate SS. Therefore, since the sapphire substrate SS has a high refractive index, the transmitted light may be distorted.

[0063] According to an embodiment, although the sapphire substrate SS can be configured to have high structural stability (e.g., durability characteristics and scratch resistance characteristics), the refractive index and thickness of the first cover layer CL1, the second cover layer CL2, and the third cover layer CL3 that can be disposed on the sapphire substrate SS can be optimized so that the display device can have improved reflection characteristics for reflection of external light while having excellent or minimal color shift or ΔE characteristics.

[0064] The first capping layer CL1 may be disposed on the sapphire substrate SS. The first capping layer CL1 may be disposed between the sapphire substrate SS and the second capping layer CL2.

[0065] In some embodiments, a first surface (eg, a surface) of the first cover layer CL1 may be in contact with the sapphire substrate SS. A second surface (eg, another surface) of the first cover layer CL1 may be in contact with the second cover layer CL2.

[0066] The first cover layer CL1 may have a refractive index n 1 . Refractive index n 1 The refractive index n may be within the range of about 1.24 to about 1.52. 1 It may be about 1.38. However, the present disclosure may not be limited thereto.

[0067] In some embodiments, the refractive index of each of the layers disclosed in the present specification may be defined as a refractive index with respect to light having a wavelength of about 550 nm.

[0068] The first cover layer CL1 may include a single layer. However, the present disclosure may not be limited thereto.

[0069] The first capping layer CL1 may include fluorine. For example, the first capping layer CL1 may include MgF 2 In some embodiments, the first capping layer CL1 may include MgF 2 The crystal structure formed.

[0070] The first cover layer CL1 may have a thickness t 1 In some embodiments, the first cover layer CL1 may have a thickness smaller than that of each of the other layers forming the cover layer COL. The first cover layer CL1 may be the thinnest layer among the cover layer COL.

[0071] For example, the thickness t 1 It can be smaller than the thickness of the sapphire substrate SS. 1 It can be smaller than the thickness t of the second cover layer CL2 2 In some embodiments, the thickness t 1 It can be smaller than the thickness t of the third cover layer CL3 3 .

[0072] In some embodiments, the thickness t 1 It can be less than about 50 nm. 1 The thickness t may be in the range of about 16 nm to about 26 nm. 1 It can be in the range of about 18 nm to about 24 nm. For example, the thickness t 1 It may be about 21 nm.

[0073] In some embodiments, the first cover layer CL1 may be a low-refractive layer, and may have a relatively low refractive index and reduce reflection of external light.

[0074] Experimentally, when the thickness of the low refractive structure may not be large enough, it may not be enough to produce the technical effect of low reflection. The thickness of the first cover layer CL1 can be optimized relative to other layers provided in the cover layer COL, and can maximize the technical effect of reducing the reflection of external light and improving the ΔE characteristic.

[0075] The second cover layer CL2 may be disposed on the first cover layer CL1. The second cover layer CL2 may be disposed between the first cover layer CL1 and the third cover layer CL3.

[0076] In some embodiments, a first surface (eg, a surface) of the second cover layer CL2 may be in contact with the first cover layer CL1. A second surface (eg, another surface) of the second cover layer CL2 may be in contact with the third cover layer CL3.

[0077] The second cover layer CL2 may have a refractive index n 2 . Refractive index n 2 The refractive index n may be in the range of about 1.3 to about 1.6. 2 In some embodiments, the refractive index n 2 It may be about 1.48. However, the present disclosure may not be limited thereto.

[0078] The second capping layer CL2 may include silicon oxide (SiO x ) mixed with additional materials. In some embodiments, the additional material may include aluminum (Al), aluminum oxide (Al x O y )(For example, Al 2 O 3 ), at least one material selected from the group consisting of yttrium (Y), magnesium (Mg), zirconium (Zr), calcium (Ca), barium (Ba), titanium (Ti), tantalum (Ta), molybdenum (Mo) and germanium (Ge).

[0079] For example, the second capping layer CL2 may include silicon oxide (SiO x ) and aluminum oxide (AlO x For example, the second capping layer CL2 may include SiO 2 and Al 2 O 3 The SiO in the second cover layer CL2 2 and Al 2 O 3 It can exist as a substitutional solid solution. For example, SiO in the second cover layer CL2 2 and Al 2 O 3 can replace each other to form a structure (e.g., a crystal structure). 9 Al 2 O 10 May be included in the second cover layer CL2.

[0080] In some embodiments, the second capping layer CL2 may have a structure in which Al may be included in silicon oxide (SiO x ) in a structure, and Al may be included in a range of about 0.1% to about 20%, which can be expressed as atomic percentage.

[0081] The second capping layer CL2 may have a thickness t 2 In some embodiments, the second capping layer CL2 may have a thickness greater than that of each of other layers disposed on the sapphire substrate SS.

[0082] For example, the thickness t 2 can be greater than the thickness t of the first cover layer CL1 1 and the thickness t of the third cover layer CL3 3 Each of the .

[0083] In some embodiments, the thickness t 2 The thickness t may be greater than about 25 nm. 2 The thickness t may be in the range of about 45 nm to about 70 nm. 2 The thickness t may be in the range of about 51 nm to about 66 nm. 2 It can be in the range of about 52 nm to about 64 nm. For example, the thickness t 2 It may be about 58 nm.

[0084] In some embodiments, the second cover layer CL2 may be an adhesive layer, and may allow the first cover layer CL1 and the third cover layer CL3 adjacent to each other to adhere to each other.

[0085] The thickness of the second cover layer CL2 may be optimized relative to other layers disposed in the cover layer COL, and may achieve technical effects of reducing reflection of external light and reducing or minimizing color shift (ie, ΔE characteristics) while sufficiently ensuring adhesion performance.

[0086] The third cover layer CL3 may be disposed on the second cover layer CL2.

[0087] In some embodiments, a first surface (eg, a surface) of the third cover layer CL3 may be in contact with the second cover layer CL2. A second surface (eg, another surface) of the third cover layer CL3 may be exposed.

[0088] The third cover layer CL3 may have a refractive index n 3 . Refractive index n 3 It may be in the range of about 1.05 to about 1.59. In some embodiments, the refractive index n 3 It may be about 1.32. However, the present disclosure may not be limited thereto.

[0089] The third cover layer CL3 may have a thickness t 3 In some embodiments, the third capping layer CL3 may have a thickness corresponding to an average thickness of other layers disposed on the sapphire substrate SS.

[0090] For example, the thickness t of the third cover layer CL3 is 3 can be greater than the thickness t of the first cover layer CL1 1 The thickness of the third cover layer CL3 is 3 It can be smaller than the thickness t of the second cover layer CL2 2 .

[0091] In some embodiments, the thickness t of the third cover layer CL3 is 3 The thickness t may be in the range of about 10 nm to about 40 nm. 3 It can be in the range of about 10 nm to about 45 nm. In some embodiments, the thickness t 3 The thickness t may be greater than about 30 nm. 3 The thickness t may be in the range of about 28 nm to about 43 nm. 3 It can be in the range of about 32 nm to about 40 nm. For example, the thickness t 3 It may be about 36 nm.

[0092] The third cover layer CL3 may include a material for realizing an anti-reflection function. For example, the third cover layer CL3 may include perfluoropolyether (PEPE). In some embodiments, the third cover layer CL3 may include a material in which a siloxane linker and two or more silyl groups may be coupled to a polymer including PEPE. In the case where the third cover layer CL3 includes PEPE, excellent anti-fingerprint properties may be achieved. However, the present disclosure may not necessarily be limited thereto.

[0093] The thickness of the third cover layer CL3 is t 3 It can be optimized with respect to other layers forming the cover layer COL, and the technical effects of reduction in reflection of external light and reduction in color shift can be achieved while the anti-fingerprint property can be ensured.

[0094] According to an embodiment, the cover layer COL may have a transmittance of about 92.5% or more with respect to light having a wavelength of about 550 nm. In some embodiments, the cover layer COL may have a transmittance of about 91.2% or more with respect to light having a wavelength of about 550 nm.

[0095] According to an embodiment, the cover layer COL may have a reflectivity of about 8.5% or less with respect to light having a wavelength of about 550 nm. In some embodiments, the cover layer COL may have a reflectivity of about 8.4% or less with respect to light having a wavelength of about 550 nm.

[0096] Hereinafter, the present disclosure will be described in more detail based on embodiments and comparative examples. However, the following embodiments and comparative examples are merely examples for describing the present disclosure in more detail, and the present disclosure may not be limited to the following embodiments and comparative examples.

[0097] Using electron beam evaporation will include MgF 2 The first cover layer CL1 includes Si 9 Al 2 O 10 The second cover layer CL2 including PEPE and the third cover layer CL3 including PEPE are sequentially stacked on the sapphire substrate SS, and the cover layer COL according to the embodiment is manufactured.

[0098] In the capping layer COL according to the embodiment, the first capping layer CL1 is formed to have a thickness of about 21 nm, the second capping layer CL2 is formed to have a thickness of about 58 nm, and the third capping layer CL3 is formed to have a thickness of about 36 nm.

[0099] In order to more thoroughly ensure the reliability of the experimental results, the cover layers COL according to the three embodiments are manufactured using the same manufacturing method. Hereinafter, the manufactured cover layers COL may be designated as Embodiment 1, Embodiment 2, and Embodiment 3, respectively.

[0100] The cover layer according to the comparative example was manufactured using the same method as the embodiment except for the thickness of each of the first cover layer CL1 , the second cover layer CL2 , and the third cover layer CL3 .

[0101] In the cover layer according to the comparative example, the first cover layer is formed to have a thickness of about 70 nm, the second cover layer is formed to have a thickness of about 15 nm, and the third cover layer is formed to have a thickness of about 36 nm.

[0102] Similar to the manufacturing of the cover layer COL according to the above embodiment, in order to more thoroughly ensure the reliability of the experimental results, a plurality of cover layers according to three comparative examples were manufactured using the same manufacturing method.

[0103] An experiment of measuring the color shift (ie, delta E or ΔE) of the cover layers manufactured according to Embodiments 1 to 3 and Comparative Examples 1 to 3 was performed.

[0104] In this experiment, a D65 light source (i.e., a standard daylight light source) which is one of the International Commission on Illumination (CIE) light sources is used. In the case where the light source is incident vertically on each of the covering layers relative to the covering layer, the color coordinate position of the identification light is set as a reference position. In the case where the light source is incident on each of the covering layers at an incident illumination angle in the range of about 0 degrees to about 60 degrees, the color coordinate position is calculated, and color shift data is calculated based on the calculated color coordinate position. The color shift can be a numerical value determined based on a reference position, and means the difference between the calculated (or expected) color coordinates and the observed color coordinates as a reference position. The equipment used in this experiment can be a spectrophotometer (model name: CM-3700A) manufactured by Minolta Co., Ltd.

[0105] Table 1

[0106]

[0107] Referring to Table 1, in the case of the cover layer COL according to the embodiment, it can be seen that the color shift characteristic is excellent compared with the cover layer according to the comparative example. Therefore, according to the cover layer COL according to the embodiment, a display device having excellent display quality according to a viewing angle can be provided.

[0108] An experiment was performed to measure the transmittance characteristics of the cover layer COL manufactured according to Embodiments 1 to 3. In order to verify the transmittance improvement effect of the cover layer COL according to the embodiment, the same experiment was performed using a sapphire substrate on which the cover layer COL was not provided. Hereinafter, the sapphire substrate is designated as a reference.

[0109] In this experiment, light with a wavelength of about 550 nm was applied to each of the cover layer COL and the sapphire substrate as a reference from the sapphire substrate surface to the top, and the intensity of the transmitted light was measured. Accordingly, the ratio of the intensity of the transmitted light to the intensity of the applied light was calculated. The equipment used in this experiment was a spectrophotometer manufactured by Minolta Co., Ltd. (model name: CM-3700A).

[0110] Table 2

[0111]

[0112]

[0113] Referring to Table 2, in the case where the capping layer COL according to the embodiment is provided on the sapphire substrate, it can be seen that the transmittance characteristics are superior compared to the case where the capping layer COL is not provided.

[0114] An experiment was performed to measure the reflectivity of the cover layer COL manufactured according to Embodiments 1 to 3. In order to verify the reflectivity improvement effect of the cover layer COL according to the embodiment, the same experiment was performed using a sapphire substrate on which the cover layer COL was not provided. Hereinafter, the sapphire substrate is designated as a reference.

[0115] In this experiment, light having a wavelength of about 550 nm was applied to each of the cover layer COL and the sapphire substrate as a reference toward the upper surface, and the intensity of the reflected light was measured. Accordingly, the ratio of the intensity of the reflected light to the intensity of the applied light was calculated. The equipment used in this experiment was a spectrophotometer manufactured by Minolta Co., Ltd. (model name: CM-3700A).

[0116] Table 3

[0117] Classification Reflectivity(%) Implementation Method 1 8.37 Implementation Method 2 8.39 Implementation 3 8.39 refer to 14.41

[0118] Referring to Table 3, in the case where the cap layer COL according to the embodiment is provided on the sapphire substrate, it can be seen that the reflectivity characteristics are superior compared to the case where the cap layer COL is not provided.

[0119] In summary, according to the embodiments of the present disclosure, a display device can be realized in which the color shift characteristic can be significantly improved, while the transmittance characteristic and the reflectance characteristic can also be improved.

[0120] According to the present disclosure, a display device having a cover layer and the cover layer in which reflection of external light can be controlled, so that visibility can be improved.

[0121] According to the present disclosure, a display device having a cover layer and the cover layer in which excellent color shift (ΔE) characteristics can be provided can be provided, so that the reliability of display quality can be improved.

[0122] Exemplary embodiments have been disclosed herein, and although specific terms may be employed, they may be used and interpreted only in a general and descriptive sense, and not for purposes of limitation. In some cases, as will be apparent to one of ordinary skill in the art upon filing this application, unless otherwise expressly stated, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments. Therefore, it will be understood by those skilled in the art that various changes may be made in form and detail without departing from the spirit and scope of the present disclosure as set forth in the appended claims.

Claims

1. A covering layer, comprising: Sapphire substrate; a first covering layer disposed on the sapphire substrate, the first covering layer comprising MgF2, the first covering layer having a thickness in a range of 16 nm to 26 nm; A second covering layer is disposed on the first covering layer, wherein the second covering layer comprises Si9Al2O 10 , the second covering layer has a thickness in the range of 45 nm to 70 nm; as well as A third covering layer is disposed on the second covering layer, the third covering layer includes perfluoropolyether, and the third covering layer has a thickness in a range of 10 nm to 45 nm.

2. The covering layer according to claim 1, wherein The surface of the first covering layer is in contact with the sapphire substrate, The other surface of the first cover layer is in contact with the surface of the second cover layer, and The other surface of the second cover layer is in contact with a surface of the third cover layer.

3. The covering layer according to claim 1, wherein: The first capping layer includes a crystal structure including MgF 2 .

4. The covering layer according to claim 1, wherein: The refractive index of the first cover layer is in the range of 1.24 to 1.

52.

5. The covering layer according to claim 1, wherein The thickness of the first capping layer is in the range of 18 nm to 24 nm.

6. The covering layer according to claim 1, wherein The second cover layer couples the first cover layer to the third cover layer.

7. The covering layer according to claim 1, wherein: The refractive index of the second cover layer is in the range of 1.33 to 1.

63.

8. The covering layer according to claim 1, wherein The thickness of the second capping layer is in the range of 52 nm to 64 nm.

9. The covering layer according to claim 1, wherein: The other surface of the third covering layer is exposed.

10. The covering layer according to claim 1, wherein The refractive index of the third cover layer is in the range of 1.05 to 1.

59.

11. The covering layer according to claim 1, wherein: The thickness of the third capping layer is in the range of 32 nm to 40 nm.

12. The covering layer according to claim 1, wherein: The refractive index of the sapphire substrate is 1.

77. The refractive index of the first covering layer is 1.38, The refractive index of the second covering layer is 1.48, and The refractive index of the third covering layer is 1.

32.

13. A display device, comprising: a light emitting element layer including a light emitting element that emits light; as well as a covering layer, disposed on the light emitting element layer, Wherein, the covering layer comprises: Sapphire substrate; a first covering layer disposed on the sapphire substrate, the first covering layer comprising MgF2, the first covering layer having a thickness in a range of 16 nm to 26 nm; A second covering layer is disposed on the first covering layer, wherein the second covering layer comprises Si9Al2O 10 , the second capping layer has a thickness in a range of 45 nm to 70 nm; and A third covering layer is disposed on the second covering layer, the third covering layer includes perfluoropolyether, and the third covering layer has a thickness in a range of 10 nm to 45 nm.

14. The display device according to claim 13, wherein: A sum of the thicknesses of the first cover layer, the second cover layer, and the third cover layer is in a range of 80 nm to 130 nm.

15. The display device according to claim 13, wherein: The refractive index of the sapphire substrate is in the range of 1.60 to 1.

95.

16. The display device according to claim 13, wherein: The cover layer has a transmittance of at least 91.2% with respect to light having a wavelength of 550 nm, and a reflectance of less than 8.50% with respect to light having a wavelength of 550 nm.

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