Display device

Abstract

The invention relates to a display device. The display device includes: a base substrate including a pixel region and a non-pixel region; an overcoat layer on the base substrate, the overcoat layer including a groove located at a region corresponding to the non-pixel region; a first electrode on the overcoat layer at a region corresponding to the pixel region; a light emitting layer in the recess and on the first electrode; and a second electrode on the light emitting layer, the second electrode being located at a region corresponding to the pixel region and in the groove.

Description

Technical Field

[0001] The present disclosure relates to an electronic device having a display, and more particularly, to a display device having improved light extraction efficiency. Background Art

[0002] With the development of the information society, display technologies have been rapidly developed to meet various needs for visually expressing information, data, applications, etc. In fact, various types of display devices having excellent performances such as thin form, light weight, and low power consumption have been developed.

[0003] Such display devices may include a liquid crystal display (LCD) device, a plasma display panel (PDP) device, a quantum dot (QD) display device, an organic light emitting diode (OLED) display device, a field emission display (FED) device, etc.

[0004] Among these display devices, an organic light emitting display device may provide advantages of light weight and thin package due to not requiring a separate light source such as a backlight, and low power consumption based on low voltage driving.

[0005] In the case of an organic light emitting display device, light emitted from a light emitting layer may leave the display device by passing through various elements and / or layers; however, when leaving the display device, a considerable portion of the emitted light may be lost. The amount of light reaching the outside may be only about 20% of the light emitted from the light emitting layer.

[0006] The amount of light emitted from the light emitting layer may increase in proportion to the amount of current applied thereto. To increase the brightness of the display device, more current needs to be provided to the display device, which results in an increase in power consumption. Therefore, it is necessary to improve the light extraction efficiency. Summary of the Invention

[0007] To solve these problems, inventors of the present disclosure have developed a technique of applying a microlens array (MLA) structure to an outer coating of a display device.

[0008] However, in an example of applying a microlens array to a display device, due to the curvature of the microlens array, the phase shift of incident light from the outside may be shifted beyond a preset range. In this case, when passing through a base substrate, the incident light and the outgoing light may travel in the same phase, and the incident light cannot be effectively shielded. Therefore, the ratio of reflected light to incident light and / or outgoing light may increase, and a black image defect in which black is not presented at an expected brightness may occur. As a result, in a display device having such a microlens array, black visibility may deteriorate.

[0009] To solve these problems, the inventors of the present disclosure have invented a display device that has improved light efficiency without using a microlens array (MLA) structure by providing a light scattering portion for scattering waveguide mode light in an outer coating.

[0010] Accordingly, embodiments of the present disclosure relate to a display device that substantially eliminates one or more problems caused by the limitations and disadvantages of the related art.

[0011] One aspect of the present disclosure is to provide a display device capable of improving light efficiency without using a microlens array (MLA) structure by including a light scattering portion for scattering waveguide mode light so that the scattered light can exit the display device along various paths.

[0012] One aspect of the present disclosure is to provide a display device that can improve light efficiency without using a microlens array (MLA) structure, reduce the ratio of reflected light to light emitted from a light source, and correct black image defects.

[0013] One aspect of the present disclosure is to provide a display device having improved front, left, and right viewing angles by including a light scattering portion for scattering light in a waveguide mode in which light is totally reflected at an interface between a light emitting layer and an insulating layer such as an outer coating and then travels laterally (e.g., to the left or right) (which may be referred to as "waveguide mode light"), so that the scattered light travels in various optical paths.

[0014] One aspect of the present disclosure is to provide a display device having improved brightness by disposing a second electrode serving as a reflective electrode in a groove of an outer coating; and causing waveguide mode light that is totally reflected at an interface between a light emitting layer and an insulating layer such as an outer coating and then travels laterally (e.g., to the left or right) to be reflected again by the second electrode and then travel to the outside.

[0015] One aspect of the present disclosure is to provide a display device that can operate at low power because the light extraction efficiency is improved by a light scattering portion and a second electrode disposed in an outer coating.

[0016] Additional features and aspects will be set forth in the following description, and in part will be apparent from the description, or may be learned by practice of the inventive concepts provided herein. Other features and aspects of the inventive concepts may be realized and obtained by the structures specifically pointed out in the written description or derivable therefrom, their claims, and the drawings.

[0017] To achieve these and other aspects of the inventive concept, as implemented and broadly described, a display device may include: a base substrate including a pixel region and a non-pixel region; an outer coating on the base substrate, the outer coating including a groove at a region corresponding to the non-pixel region; a first electrode located on the outer coating at a region corresponding to the pixel region; a light-emitting layer located in the groove and on the first electrode; and a second electrode on the light-emitting layer, the second electrode located at a region corresponding to the pixel region and in the groove.

[0018] In another aspect, a display device may include: a base substrate including a pixel region and a non-pixel region; an outer coating on the base substrate, the outer coating including a recessed space in a region corresponding to the pixel region or the non-pixel region, wherein a light-scattering portion is located in the recessed space; a first electrode located on the outer coating in a region corresponding to the pixel region; a light-emitting layer on the first electrode; and a second electrode on the light-emitting layer.

[0019] It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the claimed inventive concept. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this application. The drawings illustrate aspects of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. In the drawings:

[0021] Figure 1 An example system configuration of a display device according to aspects of the present disclosure is shown;

[0022] Figure 2 is according to aspects of the present disclosure Figure 1 An example plan view of the shown display device taken along line A-A' is shown;

[0023] Figure 3 is along Figure 2 An example cross-sectional view taken along line B-B' in is shown;

[0024] Figure 4 Shows an example light traveling path in a display device according to aspects of the present disclosure Figure 3 of;

[0025] Figure 5 An example light traveling path in a display device is shown;

[0026] Figure 6A An example arrangement in which a light-scattering portion is provided on an outer coating is shown;

[0027] Figure 6B Shows an example arrangement in which the light scattering portion is disposed below the outer coating;

[0028] Figure 7 Is a table showing the luminance improvement rate and the luminance half-viewing angle of the weight of the light scattering portion included in the outer coating according to Figure 6A And Figure 6B ;

[0029] Figure 8 Is a graph showing an example of the luminance improvement rate of the weight of the light scattering portion included in the outer coating according to Figure 6A And Figure 6B ;

[0030] Figure 9 Is a table showing an example of the light efficiency and the half-viewing angle according to the position of the light scattering portion;

[0031] Figures 10 to 13 Is an example cross-sectional view of a display device according to aspects of the present disclosure;

[0032] Figure 14 Is another example cross-sectional view of a display device according to aspects of the present disclosure;

[0033] Figure 15 Is another example cross-sectional view of a display device according to aspects of the present disclosure;

[0034] Figure 16 Is an example cross-sectional view taken along the line C-C' in Figure 15 ; and

[0035] Figure 17 Shows an example light traveling path in the display device of Figure 16 ; DETAILED DESCRIPTION OF THE INVENTION

[0036] Now, embodiments of the present disclosure will be described in detail, and examples thereof can be shown in the drawings.

[0037] In the following description, the structures, embodiments, implementations, methods, and operations described herein are not limited to one or more of the specific examples set forth herein and may vary as known in the art, unless otherwise specified. Unless otherwise specified, the same reference numerals always denote the same elements. The names of the various elements used in the following description are merely selected for convenience in writing the specification and may thus be different from those used in actual products. The advantages and features of the present disclosure, and the methods for realizing them, will be elucidated by the following exemplary embodiments described with reference to the drawings. However, the present disclosure may be implemented in different forms and should not be construed as limited to the exemplary embodiments set forth herein. On the contrary, these exemplary embodiments are provided so that the present disclosure may be thorough and complete and may help those skilled in the art fully understand the scope of the present disclosure. Further, the scope of protection of the present disclosure is defined by the claims and their equivalents. In the following description, detailed descriptions of related known functions or configurations may be omitted where such descriptions may unnecessarily obscure aspects of the present disclosure. The shapes, sizes, ratios, angles, quantities, etc. shown in the drawings to describe the various exemplary embodiments of the present disclosure are given only by way of example. Accordingly, the present disclosure is not limited to the illustrations in the drawings. When using terms such as "comprising," "having," "including," "containing," "constituting," "consisting of," "formed of," etc., one or more other elements may be added, unless terms such as "only" are used. Unless the context clearly indicates otherwise, elements described in the singular are intended to include a plurality of elements, and vice versa.

[0038] Although terms such as "first," "second," A, B, (a), (b), etc. may be used herein to describe various elements, these elements should not be construed as limited by these terms, as they are not used to define a specific order or precedence. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present disclosure, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element.

[0039] When referring to the first element being "connected or coupled," "in contact or overlapping," etc. with the second element, it should be understood that not only can the first element be "directly connected or coupled" or "directly in contact or overlapping" with the second element, but also a third element may be "interposed" between the first element and the second element, or the first element and the second element may be "connected or coupled," "in contact or overlapping," etc. with each other via a fourth element. Here, the second element may be included in at least one of two or more elements that are "connected or coupled," "in contact or overlapping," etc. with each other.

[0040] When describing positional relationships, for example, when using terms such as "on", "above", "below", "over", "under", "beside", "near", etc. to describe the positional relationship between two components, unless more restrictive terms such as "immediately", "directly", or "adjacent" are used, one or more other components may be located between the two components. For example, when one element or layer is disposed "on" another element or layer, a third element or layer may be interposed therebetween. In addition, terms such as "left", "right", "top", "bottom", "down", "up", "above", "below", etc. refer to any reference system.

[0041] In addition, when referring to any dimensions, relative sizes, etc., the numerical values or corresponding information of elements or features (e.g., horizontal, range, etc.) should be considered to include tolerances or error ranges that may be caused by various factors (e.g., process factors, internal or external influences, noise, etc.), even if the relevant descriptions are not specified. In addition, the term "may" fully encompasses all meanings of the term "can".

[0042] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0043] Figure 1 An exemplary system configuration of a display device 100 according to aspects of the present disclosure is shown.

[0044] As Figure 1 shown, in one or more aspects, the display driving system of the display device 100 may include a display panel 1 and a display driving circuit for driving the display panel 1.

[0045] The display panel 1 may include a display area AA for displaying an image and a non-display area NA for not displaying an image. The display panel 1 may include a base substrate 110 and a plurality of sub-pixels SP disposed on the base substrate 110 to display an image.

[0046] The display panel 1 may include a plurality of signal lines disposed on the base substrate 110. For example, the plurality of signal lines may include data lines DL, gate lines GL, driving voltage lines DVL, etc.

[0047] Each of the plurality of data lines DL may be arranged such that each data line DL extends in a first direction (e.g., column direction or row direction), and each of the plurality of gate lines GL may be arranged such that each gate line GL extends in a direction intersecting the first direction.

[0048] The display driving circuit may include a data driving circuit 11 and a gate driving circuit 12, and may further include a controller 13 for controlling the data driving circuit 11 and the gate driving circuit 12.

[0049] The data driving circuit 11 can output data signals (which can also be referred to as data voltages) corresponding to the image signals to a plurality of data lines DL. The gate driving circuit 12 can generate gate signals and output the generated gate signals to a plurality of gate lines GL. The controller 13 can convert the image data input from an external device or system such as the host system 14 into a data signal form interpretable by the data driving circuit 11, and provide the converted image data (Data) to the data driving circuit 11.

[0050] The data driving circuit 11 may include one or more source driver integrated circuits. For example, each source driver integrated circuit may be connected to the display panel 1 by tape automated bonding (TAB) technology, or connected to a conductive pad such as a bonding pad of the display panel 1 by chip on glass (COG) technology or chip on panel (COP) technology, or connected to the display panel 1 by chip on film (COF) technology. However, the embodiments of the present disclosure are not limited thereto.

[0051] For example, the gate driving circuit 12 may be connected to the display panel 1 by tape automated bonding (TAB) technology, or connected to a conductive pad such as a bonding pad of the display panel 1 by chip on glass (COG) technology or chip on panel (COP) technology, or connected to the display panel 1 by chip on film (COF) technology, or disposed in the non-display area NA of the display panel 1 by gate in panel (GIP) technology.

[0052] As Figure 1 shown, in one or more aspects, each of the plurality of sub-pixels SP included in the display device 100 may include a light-emitting element ED and a pixel driving circuit SPC for driving the light-emitting element ED. The pixel driving circuit SPC may include a driving transistor DRT, a scanning transistor SCT, a storage capacitor Cst, and the like.

[0053] The driving transistor DRT can drive the light-emitting element ED by controlling the current flowing into the light-emitting element ED. The scanning transistor SCT can transfer the data voltage Vdata to a second node N2 that is a gate node of the driving transistor DRT. The storage capacitor Cst can be configured to maintain the voltage at a certain level for a certain period of time.

[0054] The light-emitting element ED may include a first electrode 140, a second electrode 160, and a light-emitting layer 150 disposed between the first electrode 140 and the second electrode 160. The first electrode 140 may be a pixel electrode included in the corresponding light-emitting element ED of each sub-pixel SP, and may be electrically connected to the first node N1 of the driving transistor DRT. The second electrode 160 may be a common electrode commonly included in all or two or more corresponding light-emitting elements ED of two or more sub-pixels included in the display panel 1, and a base voltage EVSS may be applied to the second electrode 160.

[0055] In some aspects, the light-emitting element ED may be an organic light-emitting diode (OLED), a light-emitting diode (LED) based on an inorganic material, or a quantum dot light-emitting element, which is a self-luminous semiconductor crystal.

[0056] The driving transistor DRT may be a transistor for driving the light-emitting element ED, and may include a first node N1, a second node N2, and a third node N3. The first node N1 may be a source node (source electrode) or a drain node (drain electrode) of the driving transistor DRT, and may be electrically connected to the first electrode of the light-emitting element ED. The second node N2 may be a gate node of the driving transistor DRT, and may be electrically connected to the source node or the drain node of the scanning transistor SCT. The third node N3 may be a drain node (drain electrode) or a source node (source electrode) of the driving transistor DRT, and may be electrically connected to a driving voltage line DVL for providing a driving voltage EVDD. Hereinafter, for the sake of convenience of explanation only, discussion may be made based on an example in which the first node, the second node, and the third node (N1, N2, and N3) of the driving transistor DT are the source node, the gate node, and the drain node, respectively. However, embodiments of the present disclosure are not limited thereto.

[0057] The scanning transistor SCT may control the connection between the data line DL and the second node N2 of the driving transistor DRT. For example, the scanning transistor SCT may control the connection between the corresponding data line DL among the plurality of data lines DL and the second node N2 of the driving transistor DRT according to a scan signal SCAN delivered through the corresponding scan line SCL among the plurality of scan lines SCL (which is a type of gate line). A storage capacitor Cst may be disposed between the first node N1 and the second node N2 of the driving transistor DRT.

[0058] Figure 1The structure of the sub-pixel SP shown is merely an example for explanation. For example, the sub-pixel SP may further include one or more transistors or one or more capacitors. For example, each of the plurality of sub-pixels may have the same structure, or one or more of the plurality of sub-pixels may have a structure different from one or more of the other sub-pixels. The driving transistor DRT and the scanning transistor SCT may be n-type transistors or p-type transistors.

[0059] Figure 2 in accordance with aspects of the present disclosure Figure 1 The example plan view taken along line A-A' of the display device 100 shown. Figure 3 is taken along Figure 2 the line B-B' in Figure 4 shows an example light traveling path in the Figure 3 display device 100 in accordance with aspects of the present disclosure.

[0060] Referring to Figures 2 to 4 , in one or more aspects, the display device 100 may include a base substrate 110, at least one color filter 120, an outer coating 130, a first electrode 140, a light-emitting layer 150, and a second electrode 160.

[0061] The base substrate 110 may be used to support various components of the display device 100 and may include an insulating material such as a glass substrate, a plastic substrate, etc. The base substrate 110 may include a pixel region PXA in which circuit elements and at least one light-emitting element ED included in at least one sub-pixel SP are provided, and a non-pixel region NPXA provided around the pixel region PXA (e.g., outside the pixel region PXA). The non-pixel region NPXA may include boundaries between adjacent sub-pixels SP and / or a non-display region NA.

[0062] Various signal lines may be provided in the non-pixel region NPXA of the base substrate 110. For example, at least one data line DL may be provided on a first side of the first electrode 140, and a driving voltage line DVL may be provided on a second opposite side of the first electrode 140. The at least one data line DL and the driving voltage line DVL may be protected by a buffer layer 111 and a bank 112.

[0063] A plurality of color filters 120 may be provided on the buffer layer 111 such that the plurality of color filters 120 are spaced apart from each other. Each of the plurality of color filters 120 may be configured to correspond to the color of the corresponding sub-pixel SP. For example, when each pixel includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel, the color filters 120 may correspondingly include a red color filter 120, a green color filter 120, and a blue color filter 120.

[0064] The outer coating 130 may be a planarization layer for reducing the height difference between the layers or structures below the outer coating 130, and may be disposed on the base substrate 110. For example, the outer coating 130 may have a groove 130a recessed in the region corresponding to the non-pixel area NPXA, and may include an organic material such as polyimide, benzocyclobutene series resin, acrylate, etc.

[0065] The outer coating 130 may have a refractive index of 1.4 to 1.6, and may include a first layer 131 and a second layer 132. The first layer 131 may be disposed on the base substrate 110, and may reduce the height difference between the layers or structures below the outer coating 130.

[0066] The second layer 132 may be disposed on the first layer 131, and the groove 130a of the outer coating 130 may be a hole or opening formed at a part of the second layer 132. For example, the groove 130a may be disposed in the region corresponding to the non-pixel area NPXA, and two side surfaces of the groove 130a may be configured with inclined surfaces 130aa, and the inclined surfaces 130aa are formed such that the width between the inclined surfaces becomes smaller in the downward direction. For example, the side surfaces of the groove 130a may be configured with inclined surfaces 130aa, and the bottom of the groove 130a may be configured with a bottom surface 130ab that contacts the top of the first layer 131. For example, the groove 130a may be configured in a "︺" shape. For example, the groove 130a may define a flat-bottom V shape. In addition, the inclined surface 130aa may be configured to have an inclination of 30° to 70°.

[0067] The first electrode 140 may be an anode, and each sub-pixel SP may include a corresponding first electrode 140. For example, each of the plurality of first electrodes 140 may be disposed on a part of the outer coating 130 corresponding to the pixel area PXA of the corresponding sub-pixel SP among the plurality of sub-pixels SP. The first electrode 140 may not exist in the groove 130a.

[0068] The first electrode 140 may be configured with a transparent electrode such as indium tin oxide (ITO), indium zinc oxide (IZO), or an opaque electrode such as aluminum (Al), copper (Cu), nickel (Ni). For example, the first electrode 140 may have a structure in which at least one transparent electrode and at least one opaque electrode are laminated.

[0069] The light-emitting layer 150 may be disposed on the groove 130a and the first electrode 140. For example, the light-emitting layer 150 may be disposed in the pixel area PXA and the non-pixel area NPXA, and may be disposed in the groove 130a in the non-pixel area NPXA.

[0070] For example, the light-emitting layer 150 may be an organic compound layer and include a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), etc. The light-emitting layer 150 may be disposed in the pixel region PXA and the non-pixel region NPXA.

[0071] The second electrode 160 may be a cathode and may be disposed on the light-emitting layer 150. For example, the second electrode 160 may be disposed in the pixel region PXA and the non-pixel region NPXA and may be disposed in the groove 130a in the non-pixel region NPXA.

[0072] In one or more aspects, the second electrode 160 may be used as a reflective electrode and may include a reflective material. To be used as a reflective electrode, the second electrode 160 may be configured with an opaque electrode having good reflectivity, such as aluminum (Al), copper (Cu), nickel (Ni), etc. For example, the second electrode 160 may have a structure in which a transparent electrode such as indium tin oxide (ITO) or indium zinc oxide (IZO) and an opaque electrode are stacked.

[0073] According to the above example, since the second electrode 160 used as a reflective electrode is disposed in the groove 130a of the outer coating 130, the brightness of the display device 100 can be increased by extracting the waveguide mode light to the outside.

[0074] Figure 5 An example of the traveling path of light emitted from the light-emitting element of the display panel 1 is shown. Refer to Figure 5 The waveguide mode is defined.

[0075] As Figure 5 shown, some of the light generated in the light-emitting layer 150 may not be emitted from the display panel 1 due to the refractive index difference between the light-emitting layer 150 and the layer in contact with the light-emitting layer 150 and may be totally reflected. The totally reflected light that fails to be emitted from the display panel 1 may be trapped within one or more layers or structures of the display panel 1. In some cases where some of the generated light is totally reflected in the light-emitting layer 150, the loss mode caused when the thickness (d) of the light-emitting layer 150 is similar to the wavelength (λ) of the totally reflected light (e.g., d≒λ; the thickness is approximately equal to the wavelength) may be referred to as the waveguide mode. The waveguide mode may be a reason for reducing the light extraction efficiency because the light totally reflected at the interface between the light-emitting layer 150 and the layer in contact with the light-emitting layer 150 (e.g., the outer coating 130) may disappear after traveling laterally (e.g., to the left or right).

[0076] To solve the waveguide mode problem, in one or more aspects, the display device 100 may have a structure in which the second electrode 160 is disposed in the groove 130a of the outer coating 130, as Figure 4As shown. For example, as Figure 4 shown, even if the light travels laterally (e.g., the light travels in a waveguide manner), the light can be reflected again by the second electrode 160 disposed in the groove 130a, so that it exits from the display device 100.

[0077] By adopting this configuration, the light extraction efficiency can be improved, and furthermore, the display device 100 can be operated at low power based on the improved light extraction efficiency.

[0078] In one or more aspects, the outer coating 130 may further include a light scattering portion 170 for scattering waveguide mode light. For example, the light scattering portion 170 may be disposed between the first electrode 140 and the groove 130a, and may be arranged so that the light scattering portion 170 does not overlap with the first electrode 140.

[0079] The light scattering portion 170 may include a transparent resin 171 containing light scattering particles 172. The transparent resin 171 may include acrylic, polyurethane, epoxy resin, vinyl, polyester, and / or polyamide resin having excellent light transmittance and easy viscosity control. The light scattering particles 172 included in the transparent resin 171 may have a size of micrometers (μm) or less, and may include TiO2 or SiO2.

[0080] The transparent resin 171 and the light scattering particles 172 may have different refractive indices. For example, the refractive index of the transparent resin 171 may be 1.4 to 1.6, and the refractive index of the light scattering particles 172 may be 2.3 to 2.5.

[0081] Due to this difference in refractive index, when the light reflected at the interface between the light emitting layer 150 and the base substrate 110 reaches the light scattering portion 170, the reflected light can be scattered by the light scattering portion 170 and made to travel along various optical paths. By providing the light scattering portion 170, since the reflected light travels in various optical paths, the display device 100 can provide an improved front view angle, left view angle, and / or right view angle.

[0082] In addition, even if the light reflected at the interface between the light emitting layer 150 and the outer coating 130 passes through the light scattering portion 170 and travels laterally, the light can be reflected by the second electrode 160 located on at least one side of the light scattering portion 170 and made to exit from the display panel 1. Therefore, the display device 100 can provide improved light extraction efficiency.

[0083] Figure 6A An example arrangement in which the light scattering portion 170 is provided on the outer coating 130 is shown. Figure 6B An example arrangement in which the light scattering portion 170 is provided below the outer coating 130 is shown. Figure 7 is a diagram showing according to Figure 6AExample arrangement and Figure 6B Example table of the brightness improvement rate and the brightness semi-viewing angle of the weight of the light scattering portion 170 included in the outer coating 130 in the example arrangement. Figure 8 Shows according to Figure 6A Example arrangement and Figure 6B Example curve graph of the brightness improvement rate of the weight of the light scattering portion 170 included in the outer coating 130 in the example arrangement.

[0084] For example, in Figure 6A Example arrangement and Figure 6B In the example arrangement, the thickness of the light scattering portion 170 can be 1 μm, the refractive index of the transparent resin 171 included in the light scattering portion 170 can be 1.53, and the refractive index of the light scattering particles 172 can be 2.46. In addition, the reflectance of the line can be 32%, and the average aperture ratio can be 37%. It should be noted that Figure 6A And Figure 6B The corresponding structure A of

[0085] With reference to Figures 6A to 8 , it can be seen that the arrangement in which the light scattering portion 170 is provided adjacent to the light emitting layer 150 provides more brightness improvement. This is because since the light scattering portion 170 is located closer to the light emitting layer 150, more waveguide mode light can be incident on the light scattering portion 170 and scattered before disappearing. Therefore, in an example where the outer coating 130 includes a first layer 131 and a second layer 132 as in the configurations of Figure 6A and Figure 3 and Figure 4 , the light scattering portion 170 can preferably be provided on the second layer 132.

[0086] In addition, it can be seen that: examples in which the weight of the light scattering portion 170 included in the outer coating 130 is 1 to 20% provide the best brightness improvement; and as the weight of the light scattering portion 170 increases, the corresponding brightness semi-viewing angle also increases proportionally. Here, the semi-viewing angle can refer to the viewing angle at which the brightness is 50% when the brightness at the center is 100%.

[0087] Based on these results, by appropriately adjusting the weight of the light scattering portion 170 included in the outer coating 130, the display device 100 can have the desired brightness and viewing angle.

[0088] Figure 9 Example table showing the light efficiency and the semi-viewing angle according to the position of the light scattering portion 170 compared with the reference structure B.

[0089] For example, in Figure 9In Case 1, the light scattering part 170 can be disposed below the first electrode 140 and overlap with the first electrode 140. In Figure 9 In Case 2, the light scattering part 170 can be disposed between the lower end of the first electrode 140 and the inclined surface 130aa of the groove 130a, and does not overlap with the first electrode 140. In Figure 9 In Case 3, the light scattering part 170 can be disposed so as to overlap with a part of the first electrode 140. In Figure 9 In Case 4, the light scattering part 170 can be disposed to be spaced apart from the first electrode 140 without overlapping with the first electrode 140. Further from Case 4, the light scattering part 170 can be disposed between the first electrode 140 and the inclined surface 130aa of the groove 130a. In addition, it should be noted that the reference structure B has a similar structure to the structures of Case 1 to Case 4, except that the corresponding light scattering parts 170 of Case 1 to Case 4 are disposed and configured differently respectively.

[0090] The example arrangement of Case 1 where the light scattering part 170 is disposed below the first electrode 140 and overlaps with the first electrode 140 Figure 9 results in poor light efficiency and a semi-viewing angle. In addition, the example arrangement of Case 2 where the light scattering part 170 is disposed between the first electrode 140 and the inclined surface 130aa of the groove 130a Figure 9 results in good light efficiency and a semi-viewing angle. Specifically, it can be seen that Case 4 where the light scattering part 170 is disposed on the inclined surface 130aa of the groove 130a without overlapping with the first electrode 140 produces the best light efficiency.

[0091] In view of these results, by appropriately setting the light scattering part 170 included in the outer coating 130, a desired brightness and viewing angle can be provided to the display device 100.

[0092] Figure 10 is a cross-sectional view of an example 100A of the display device 100 according to aspects of the present disclosure. It will be explained with respect to the differences from the previously described examples Figure 10 of the example.

[0093] In Figure 10 , the light scattering part 170 of the display device 100A can be disposed so as to overlap with the first electrode 140 in the second layer 132 of the outer coating 130. For example, the light scattering part 170 can correspond to the length of the first electrode 140 such that the two opposite side ends of the light scattering part 170 are respectively aligned with the two side ends of the first electrode 140. In this example, the width between the two side surfaces of the light scattering part 170 can become smaller in the downward direction.

[0094] Accordingly, the light-scattering part 170 may have an inclined surface that is inclined at a certain angle toward the top surface or the bottom surface of the light-scattering part 170. As in this example, when the side surface of the light-scattering part 170 is provided with an inclined surface, the light existing on (or adjacent to) the first electrode 140 or passing through the first electrode 140 may be scattered at different angles at the interface between the light-scattering part 170 and the first electrode 140. Thus, the display device 100A having this configuration may provide improved front, left, and right viewing angles.

[0095] Figure 11 FIG. is a cross-sectional view of another example 100B of the display device 100 according to aspects of the present disclosure. The example will be explained with respect to the differences from the previously described example. Figure 11 of the example.

[0096] According to Figure 11 , the light-scattering part 170 of the display device 100B may be arranged such that it overlaps with the first electrode 140 in the second layer 132 of the outer coating 130. For example, the light-scattering part 170 may have a length shorter than that of the first electrode 140 and face the central part of the first electrode 140. In this example, the width between the two side surfaces of the light-scattering part 170 may become smaller in the downward direction.

[0097] Accordingly, since the light-scattering part 170 has an inclined surface that is inclined at a certain angle toward the top surface or the bottom surface of the light-scattering part 170, the light that is totally reflected at the interface between the light-emitting layer 150 and the outer coating 130 may be scattered in more paths, so that the display device 100B having this configuration may provide improved front, left, and right viewing angles.

[0098] Figure 12 FIG. is a cross-sectional view of another example 100C of the display device 100 according to aspects of the present disclosure. The example will be explained with respect to the differences from the previously described example. Figure 12 of the example.

[0099] As Figure 12 shown, the light-scattering part 170 of the display device 100C may be arranged such that it overlaps with a part of the first electrode 140 and a part of the light-emitting layer 150 provided in the groove 130a in the second layer 132 of the outer coating 130. For example, the light-scattering part 170 may be arranged such that one side part of the light-scattering part 170 overlaps with the side part of the first electrode 140, while the other side part is arranged along the inclined surface 130aa of the groove 130a and overlaps with the light-emitting layer 150. In this example, the width between the two inclined surfaces of the light-scattering part 170 may become smaller in the upward direction.

[0100] Accordingly, the light-scattering portion 170 may have an inclined surface that is inclined at a certain angle toward the top surface or the bottom surface of the light-scattering portion 170. For example, the inclined surface of the light-scattering portion 170 may be formed at an angle corresponding to the inclined surface 130aa of the groove 130a.

[0101] Figure 13 FIG. is a cross-sectional view of another example 100D of the display device 100 according to aspects of the present disclosure. The differences from the previously described example will be explained Figure 13 of the example.

[0102] As Figure 13 shown, the light-scattering portion 170 of the display device 100D may be arranged such that it overlaps a part of the first electrode 140 and a part of the light-emitting layer 150 disposed in the groove 130a in the second layer 132 of the outer coating 130. For example, the light-scattering portion 170 may be disposed between the first electrode 140 and the groove 130a, and the upper part of the light-scattering portion 170 may have a dome shape. For example, the light-scattering portion 170 may have a hemispherical shape.

[0103] In an example where the upper part of the light-scattering portion 170 has a dome shape, the second electrode 160 disposed on the light-scattering portion 170 may also have a curved surface that matches the shape of the light-scattering portion 170. In this example, since the second electrode 160 may be arranged such that the angle of the curved region between the pixel region PXA and the non-pixel region NPXA can become smaller than the angle of a straight shape, accordingly, the display device 100D having this configuration may provide the advantage of preventing oxygen and moisture from penetrating due to connection disconnection.

[0104] Both ends of the first electrode 140 may have an arc shape corresponding to the shape of the light-scattering portion 170 and may overlap a part of the light-scattering portion 170. In an example where both ends of the first electrode 140 are arranged along the curved surface of the light-scattering portion 170, the waveguide mode light traveling toward any one side of the first electrode 140 may be made to travel forward through the curved surface of the second electrode 160. Accordingly, even when the curved surface of the second electrode 160 (or a portion corresponding to or adjacent to the curved surface) does not form an angle of 45° or more with the flat portion of the second electrode 160, the front viewing angle can be improved.

[0105] Figure 14 FIG. is another example cross-sectional view of a display device according to aspects of the present disclosure.

[0106] As Figure 14As shown, in one or more aspects, an example 200 of a display device 100 may include a base substrate 210, at least one color filter 220, an outer coating 230, a light scattering portion 240, a first electrode 250, a bank layer 260, a light emitting layer 270, and a second electrode 280.

[0107] The base substrate 210 may be configured to support various components of the display device 200, and includes a pixel region PXA provided with one or more sub-pixels SP and a non-pixel region NPXA located outside the pixel region PXA. Various signal lines may be provided in the non-pixel region NPXA of the base substrate 210. For example, at least one data line DL may be provided on a first side of the first electrode 250, and a driving voltage line DVL may be provided on a second opposite side of the first electrode 250. At least one data line DL and the driving voltage line DVL may be protected by a buffer layer 211. For example, the buffer layer 211 may include silicon oxide (SiOx), silicon nitride (SiNx), or a combination thereof.

[0108] A plurality of color filters 220 may be provided on the buffer layer 211 such that the plurality of color filters 220 are spaced apart from each other. Each of the plurality of color filters 220 may be configured to correspond to the color of a corresponding sub-pixel SP. For example, when each pixel includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel, the color filters 220 may correspondingly include a red color filter 220, a green color filter 220, and a blue color filter 220.

[0109] The outer coating 230 may be a planarization layer for reducing the height difference between layers or structures located below the outer coating 230, and may be provided on the base substrate 210. For example, the outer coating 230 may have a refractive index of 1.4 to 1.6, and includes a recessed space 230s (or a depressed space, or a hole) provided in a region corresponding to the pixel region PXA or the non-pixel region NPXA.

[0110] The light scattering portion 240 may be used to scatter waveguide mode light and is provided in the recessed space 230s. For example, the light scattering portion 240 may be formed to correspond to the shape of the recessed space 230s. Accordingly, the widths of two side surfaces of the light scattering portion 240 may also become smaller in the downward direction.

[0111] The light scattering portion 240 may include a transparent resin 241 containing light scattering particles 242.

[0112] The transparent resin 241 may include acrylic, polyurethane, epoxy resin, vinyl, polyester, and / or polyamide resin having excellent light transmittance and easy viscosity control. The light scattering particles 242 included in the transparent resin 241 may have a size of micrometers (μm) or less, and may include TiO2 or SiO2.

[0113] The transparent resin 241 and the light-scattering particles 242 may have different refractive indices. For example, the refractive index of the transparent resin 241 may be from 1.4 to 1.6, and the refractive index of the light-scattering particles 242 may be from 2.3 to 2.5.

[0114] Due to this difference in refractive index, when the light reflected at the interface between the light-emitting layer 270 and the outer coating 230 reaches the light-scattering portion 240, the reflected light can be scattered by the light-scattering portion 240 and made to travel along various optical paths. By providing the light-scattering portion 240, when the light travels along various optical paths, the display device 200 can provide an improved front viewing angle, left viewing angle, and / or right viewing angle.

[0115] The first electrode 250 may be an anode, and each sub-pixel SP may include a corresponding first electrode 250. For example, each of the plurality of first electrodes 250 may be provided on a part of the outer coating 230 corresponding to the pixel region PXA in which the corresponding sub-pixel SP among the plurality of sub-pixels SP is provided.

[0116] The first electrode 250 may be configured with a transparent electrode such as indium tin oxide (ITO), indium zinc oxide (IZO), or an opaque electrode such as aluminum (Al), copper (Cu), nickel (Ni). For example, the first electrode 250 may have a structure in which at least one transparent electrode and at least one opaque electrode are stacked.

[0117] The bank layer 260 can be used to divide one or more pixels and can be provided on the outer coating 230. For example, the bank layer 260 may include an opening for exposing a part of the first electrode 250, and light can travel through the opening.

[0118] The light-emitting layer 270 may be provided on the bank layer 260 and the first electrode 250. For example, the light-emitting layer 270 may be an organic compound layer and include a hole injection layer (HIL), a hole transport layer (HTL), an active layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), etc. The light-emitting layer 270 may be provided in the pixel region PXA and the non-pixel region NPXA.

[0119] The second electrode 280 may be a cathode and may be provided on the light-emitting layer 270. For example, the second electrode 280 may be provided in the pixel region PXA and the non-pixel region NPXA.

[0120] Figure 15 is a cross-sectional view of a display device according to aspects of the present disclosure. Figure 16 is along Figure 15 An example cross-sectional view taken along line C-C' in Figure 17 showsFigure 16 An example light traveling path in the display device. Differences from the previously described examples will be explained. Figures 15 to 17 Examples.

[0121] Referring to Figures 15 to 17 , Example 300 of the display device 100 may include a groove 230a recessed in the outer coating 230. For example, the outer coating 230 may have a refractive index of 1.4 to 1.6 and may include a first layer 231 and a second layer 232.

[0122] The first layer 231 may be disposed on the base substrate 210 and may reduce the height difference between the layers or structures located below the outer coating 230.

[0123] The second layer 232 may be disposed on the first layer 231, and the recessed space 230s and the groove 230a may be disposed on the non-pixel area NPXA. For example, the recessed space 230s may be disposed closer to the pixel area PXA than the groove 230a. The groove 230a provided in the second layer 232 may be recessed in the area corresponding to the non-pixel area NPXA, and two side surfaces of the groove 230a may be configured with inclined surfaces 230aa, and the inclined surfaces 230aa are formed such that the width between the inclined surfaces becomes smaller in the downward direction. For example, the side surface of the groove 230a may be configured with the inclined surface 230aa, and the bottom of the groove 230a may be configured with a bottom surface 230ab that contacts the top of the first layer 231.

[0124] For example, the bank layer 260, the light-emitting layer 270, and the second electrode 280 may be disposed in the groove 230a. The bank layer 260 may be used to divide one or more pixels and includes an opening configured to expose a part of the first electrode 250 and allow light to travel through the opening.

[0125] The bank layer 260 may be disposed in the groove 230a of the outer coating 230. For example, the bank layer 260 may have a lower portion separated from each other by an intermediate portion, and the intermediate portion may correspond to a part or space between the two inclined surfaces 230aa of the groove 230a, for example, a part of the bottom surface 230ab. By applying this structure, the bank layer 260 may cover at least one end of the first electrode 250 from at least one inclined surface 230aa of the groove 230a, but may not cover a part of the bottom surface 230ab of the groove 230a. Therefore, since the bank layer 260 does not exist at the bottom of the light-emitting layer 270 disposed in the groove 230a, the size of the display device 300 may be minimized.

[0126] For example, the light-scattering portion 240 provided in the outer coating 230 may not overlap with the first electrode 250. For example, the light-scattering portion 240 may be provided between the groove 230a in the non-pixel region NPXA and the first electrode 250, and the upper portion of the light-scattering portion 240 may be shielded by the bank layer 260.

[0127] The light-scattering portion 240 may be provided in the recessed space 230s provided in the second layer 232 of the outer coating 230. For example, the two side surfaces of the light-scattering portion 240 may be configured with inclined surfaces, and the inclined surfaces are formed such that the width between the inclined surfaces becomes smaller in the downward direction.

[0128] By applying the above configuration, since the light-scattering portion 240 is provided in the outer coating 230, when the light reflected at the interface of the outer coating 230 reaches the light-scattering portion 240, the light can be scattered through the light-scattering portion 240 in various paths. Therefore, since the light-scattering portion 240 causes the reflected light to travel in different paths without disappearing in the waveguide mode, the light efficiency can be improved, and the front view angle, left view angle, and right view angle can be improved.

[0129] In addition, even if the light reflected at the interface between the light-emitting layer 270 and the outer coating 230 passes through the light-scattering portion 240 and travels sideways, the light can be reflected by the second electrode 280 located on at least one side and the top of the light-scattering portion 240 and made to exit from the display device 300. Therefore, the display device 300 can provide improved light extraction efficiency.

[0130] According to one or more aspects of the present disclosure, a display device capable of improving light efficiency without adopting a microlens array (MLA) structure by including a light-scattering portion can be provided. The light-scattering portion is used to scatter waveguide-mode light so that the scattered light can exit the display device in various paths.

[0131] According to one or more aspects of the present disclosure, a display device can be provided that can improve light efficiency without adopting a microlens array (MLA) structure, reduce the ratio of reflected light to light emitted from a light source, and correct black image defects.

[0132] According to one or more aspects of the present disclosure, a display device having improved front view angle, left view angle, and right view angle by including a light-scattering portion can be provided. The light-scattering portion is used to scatter light in the waveguide mode, in which the light is totally reflected at the interface between the light-emitting layer and an insulating layer such as the outer coating and then travels sideways (e.g., left or right) (which can be referred to as "waveguide-mode light"), so that the scattered light travels in various optical paths.

[0133] According to one or more aspects of the present disclosure, a display device having improved luminance can be provided by: disposing a second electrode serving as a reflective electrode in a groove of an outer coating; and causing waveguide mode light that is totally reflected at an interface between a light-emitting layer and an insulating layer such as the outer coating and then travels laterally (e.g., left or right) to be reflected again by the second electrode and then travel outward.

[0134] According to one or more aspects of the present disclosure, a display device can be provided that can operate at low power because the light extraction efficiency is improved by a light-scattering portion and a second electrode disposed in an outer coating.

[0135] The above-described embodiments will be briefly described below.

[0136] According to aspects of the present disclosure, a display device can be provided that includes: a base substrate including a pixel region and a non-pixel region; an outer coating on the base substrate, the outer coating including a groove at a region corresponding to the non-pixel region; a first electrode on the outer coating at a region corresponding to the pixel region; a light-emitting layer in the groove and on the first electrode; and a second electrode on the light-emitting layer, the second electrode being located at a region corresponding to the pixel region and in the groove.

[0137] In one or more aspects, a side surface of the groove can be inclined, and a width of the groove at a bottom of the groove can be less than a width of the groove at a top of the groove.

[0138] In one or more aspects, an inclined surface of the groove can have an inclination of 30° to 70°.

[0139] In one or more aspects, the outer coating can include a first layer and a second layer on the first layer, and the groove is provided in the second layer.

[0140] In one or more aspects, the outer coating can further include a light-scattering portion configured to scatter light from the light-emitting layer.

[0141] In one or more aspects, a width of a bottom of the light-scattering portion can be equal to or less than a width of a top of the light-scattering portion.

[0142] In one or more aspects, an upper surface of the light-scattering portion can have a dome shape, at least one end of the first electrode has an arc shape corresponding to the dome shape of the light-scattering portion, and at least one end can overlap with respective portions of the light-scattering portion.

[0143] In one or more aspects, the light-scattering portion may be between the first electrode and the groove, and the light-scattering portion may not overlap with the first electrode.

[0144] In one or more aspects, the light-scattering portion may be under the first electrode, and the light-scattering portion may overlap with the first electrode.

[0145] In one or more aspects, the light-scattering portion may overlap with the first electrode and may overlap with the light-emitting layer in the groove.

[0146] In one or more aspects, the light-scattering portion may include a transparent resin having light-scattering particles therein.

[0147] In one or more aspects, the refractive index of the transparent resin may be 1.4 to 1.6, and the refractive index of the light-scattering particles may be 2.3 to 2.5.

[0148] In one or more aspects, the refractive index of the outer coating may be 1.4 to 1.6.

[0149] According to aspects of the present disclosure, a display device may be provided, the display device including: a base substrate including a pixel region and a non-pixel region; an outer coating on the base substrate, the outer coating including a recessed space in a region corresponding to the pixel region or the non-pixel region, wherein the light-scattering portion is located within the recessed space; a first electrode on the outer coating in a region corresponding to the pixel region; a light-emitting layer on the first electrode; and a second electrode on the light-emitting layer.

[0150] In one or more aspects, the outer coating may include a groove in a region corresponding to the non-pixel region, and the light-emitting layer and the second electrode may be located in the groove.

[0151] In one or more aspects, the side surface of the groove is inclined, and the width of the groove at the bottom of the groove is smaller than the width of the groove at the top of the groove.

[0152] In one or more aspects, the display device may further include a bank layer in the non-pixel region on the outer coating and in the groove, the bank layer including an opening for exposing a portion of the first electrode. The bank layer may have a lower portion separated from each other by an intermediate portion, and the intermediate portion may correspond to a portion or a space between the inclined side surfaces of the groove. The light-emitting layer may be further located on the bank layer.

[0153] In one or more aspects, the light-scattering portion may include a transparent resin having light-scattering particles therein.

[0154] In one or more aspects, the light scattering portion may be below the first electrode and overlap the first electrode.

[0155] In one or more aspects, the light scattering portion may be between the first electrode and the groove, and the light scattering portion may not overlap the first electrode.

[0156] It will be apparent to those skilled in the art that various modifications and variations can be made to the display device of the present disclosure without departing from the technical concept or scope of the present disclosure. Accordingly, the present disclosure is intended to cover modifications and variations of the present disclosure that fall within the scope of the appended claims and their equivalents.

[0157] This application claims the priority benefit of Korean Patent Application No. 10-2023-0197790, filed with the Korean Intellectual Property Office on December 29, 2023, which is incorporated herein by reference for all purposes as if fully set forth herein.

Claims

1. A display device, comprising: A base substrate, the base substrate comprising a pixel area and a non-pixel area; an outer coating layer on the base substrate, the outer coating layer comprising a groove located at an area corresponding to the non-pixel area; a first electrode located on the outer coating layer at an area corresponding to the pixel area; a light-emitting layer, the light-emitting layer being in the groove and on the first electrode; as well as A second electrode is on the light emitting layer, and the second electrode is located at a region corresponding to the pixel region and in the groove.

2. The display device according to claim 1, wherein: A side surface of the groove is inclined, and a width of the groove at a bottom of the groove is smaller than a width of the groove at a top of the groove.

3. The display device according to claim 2, wherein: The inclined surface of the groove has an inclination of 30° to 70°.

4. The display device according to claim 1, wherein: The outer coating layer includes a first layer, and a second layer located on the first layer, and the groove is disposed in the second layer.

5. The display device according to claim 1, wherein: The overcoat layer also includes a light scattering portion configured to scatter light from the light emitting layer.

6. The display device according to claim 5, wherein: A width of a bottom portion of the light scattering portion is equal to or smaller than a width of a top portion of the light scattering portion.

7. The display device according to claim 5, wherein: The upper surface of the light scattering portion has a dome shape, wherein at least one end of the first electrode has an arc shape corresponding to the dome shape of the light scattering portion, and Wherein, the at least one end overlaps with the light scattering portion.

8. The display device according to claim 5, wherein: The light scattering portion is between the first electrode and the groove, and wherein the light scattering portion does not overlap with the first electrode.

9. The display device according to claim 5, wherein: The light scattering portion is below and overlaps the first electrode.

10. The display device according to claim 5, wherein: The light scattering portion overlaps the first electrode and overlaps the light emitting layer in the groove.

11. The display device according to claim 5, wherein: The light scattering portion includes a transparent resin having light scattering particles therein.

12. The display device according to claim 11, wherein: The transparent resin has a refractive index of 1.4 to 1.6, and the light scattering particles have a refractive index of 2.3 to 2.

5.

13. The display device according to claim 12, wherein: The refractive index of the outer coating layer is 1.4 to 1.

6.

14. A display device, comprising: A base substrate, the base substrate comprising a pixel area and a non-pixel area; an outer coating layer on the base substrate, the outer coating layer comprising a recessed space in an area corresponding to the pixel area or the non-pixel area, wherein a light scattering portion is located in the recessed space; a first electrode located on the outer coating layer in an area corresponding to the pixel area; a light-emitting layer, the light-emitting layer being on the first electrode; and A second electrode is provided on the light-emitting layer.

15. The display device according to claim 14, wherein: The overcoat layer includes a groove in an area corresponding to the non-pixel area, and Wherein, the light-emitting layer and the second electrode are in the groove.

16. The display device according to claim 15, wherein: A side surface of the groove is inclined, and a width of the groove at a bottom of the groove is smaller than a width of the groove at a top of the groove.

17. The display device according to claim 16, further comprising a bank layer in the non-pixel region on the overcoat layer and in the groove, the bank layer comprising an opening to expose a portion of the first electrode, in, The banks have lower portions separated from each other by a middle portion, and the middle portion corresponds to a portion or a space between the inclined side surfaces of the groove.

18. The display device according to claim 14, wherein: The light scattering portion includes a transparent resin having light scattering particles therein.

19. The display device according to claim 14, wherein: The light scattering portion is below and overlaps the first electrode.

20. The display device according to claim 15, wherein: The light scattering portion is between the first electrode and the groove and does not overlap with the first electrode.

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