Display device

Abstract

A display device for improving light extraction efficiency of light emitted from a light emitting layer is provided. The display device includes: a substrate including a plurality of pixels having a plurality of sub-pixels; a pattern portion provided to be recessed in a non-emission region between the plurality of sub-pixels on the substrate; and a reflective portion disposed to be inclined on the pattern portion, in which each of the plurality of sub-pixels includes: a plurality of concave portions disposed in a light emitting region adjacent to the non-light emitting region; and a pixel electrode disposed on the plurality of concave portions, and wherein a spacing distance between the plurality of concave portions and the reflective portion is greater than a spacing distance between the pixel electrode and the reflective portion.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of Korean Patent Application No. 10 - 2023 - 0186078, filed on December 19, 2023, which is hereby incorporated by reference as if fully set forth herein. Technical field

[0003] The present disclosure relates to a display device for displaying images. Background art

[0004] Unlike liquid crystal display devices, since organic light - emitting display devices have a high response speed, low power consumption, and emit light by themselves without a separate light source, there is no problem in terms of viewing angle, and thus organic light - emitting display devices have received attention as next - generation flat - panel display devices.

[0005] Such a display device displays an image by the light emission of a light - emitting element layer, which includes a light - emitting layer interposed between two electrodes.

[0006] Meanwhile, since some of the light emitted from the light - emitting element layer is not emitted to the outside due to total internal reflection at the interfaces between multiple layers inside the display panel, the light extraction efficiency of the display device is reduced. Summary of the invention

[0007] One aspect of the present disclosure aims to provide a display device in which the light extraction efficiency from the light - emitting layer can be improved.

[0008] One aspect of the present disclosure aims to provide a display device that can reduce the overall power consumption by extracting light from non - light - emitting regions.

[0009] One aspect of the present disclosure aims to provide a display in which the light extraction efficiency can be maximized by including a plurality of concave portions in each of a plurality of sub - pixels.

[0010] The problems to be solved by the embodiments of the present disclosure are not limited to the above problems, and through the following description, other problems not mentioned above will become apparent to those skilled in the art to which the technical concept of the present disclosure pertains from the following description.

[0011] The display device includes: a substrate including a plurality of pixels each having a plurality of sub-pixels; a pattern portion disposed to be recessed in a non-light-emitting area between the plurality of sub-pixels on the substrate; and a reflection portion disposed to be inclined on the pattern portion, wherein each of the plurality of sub-pixels includes: a plurality of concave portions disposed in a light-emitting area adjacent to the non-light-emitting area; and a pixel electrode disposed on the plurality of concave portions, and wherein a distance between the plurality of concave portions and the reflection portion is greater than a distance between a pixel circuit and the reflection portion.

[0012] The technical benefits of the present disclosure are not limited to the above benefits, and those skilled in the art can clearly understand other benefits not mentioned above through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings are included to provide a further understanding of the present disclosure and are incorporated into and constitute a part of this application, in which embodiments of the present disclosure are shown, and together with the description are used to explain the principles of the present disclosure. In the drawings:

[0014] Figure 1 is a schematic plan view of a display device according to an embodiment of the present disclosure.

[0015] Figure 2 is Figure 1 a schematic plan view of one pixel shown in

[0016] Figure 3 is taken along Figure 2 a schematic cross-sectional view taken along line I-I' shown in

[0017] Figure 4 is taken along Figure 2 a schematic cross-sectional view taken along line II-II' shown in

[0018] Figure 5 is Figure 2 a schematic enlarged plan view of part A shown in

[0019] Figure 6 is Figure 3 a schematic enlarged cross-sectional view of part B shown in

[0020] Figure 7 is Figure 3 a schematic enlarged cross-sectional view of part C shown in

[0021] Figure 8 is a schematic cross-sectional view showing light refraction in one concave portion shown in Figure 7

[0022] Figure 9 ​A graph showing the light intensity as a function of the angle of light incident on the concave portion of the display device according to an embodiment of the present disclosure.

[0023] Figure 10 A graph showing the ratio of the refracted light intensity as a function of the aspect ratio of the concave portion of the display device according to an embodiment of the present disclosure. Detailed Embodiments

[0024] Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. The advantages and features of the present disclosure and the methods for realizing them will be clarified by the embodiments described below with reference to the drawings.

[0025] However, the present disclosure may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0026] The shapes, sizes, ratios, angles, and numbers disclosed in the drawings used to describe the embodiments of the present disclosure are merely examples, and thus the present disclosure is not limited to the details shown. Like reference numerals always refer to like elements. In the following description, when a detailed description of related known functions or configurations is determined to unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted.

[0027] When using "comprising", "having", and "including" described in this specification, another part may be added unless "only..." is used. Unless otherwise specified, terms in the singular form may include the plural form.

[0028] When explaining an element, although not explicitly described, the element is interpreted to include an error range. When describing a positional relationship, for example, when the positional relationship between two parts is described as "on...", "above...", "below...", and "next to...", one or more other parts may be provided between the two parts unless "exactly" or "directly" is used.

[0029] When describing a time relationship, for example, when a time sequence is described as "after...", "afterwards", "subsequently", and "before...", a discontinuous case may be included unless "only" or "directly" is used.

[0030] 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.

[0031] These terms are only used to distinguish one element from other elements. 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.

[0032] The "X-axis direction", "Y-axis direction", and "Z-axis direction" should not be interpreted only by the geometric relationship of perpendicularity to each other, and may have a broader directivity within the range where the elements of the present disclosure function.

[0033] The term "at least one" should be understood to include any and all combinations of one or more of the associated listed items. For example, the meaning of "at least one of the first item, the second item, and the third item" represents all combinations of items selected from the first item, the second item, and the third item, as well as two or more of the first item, the second item, or the third item.

[0034] The features of the various embodiments of the present disclosure may be partially or wholly coupled or combined with each other, and may interoperate and be technically driven in various ways, as can be fully understood by those skilled in the art. The embodiments of the present disclosure may be executed independently of each other, or may be executed together in a mutually dependent relationship.

[0035] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0036] Figure 1 is a schematic plan view of a display device according to an embodiment of the present disclosure, Figure 2 is Figure 1 a schematic plan view of one pixel shown in Figure 3 and Figure 2 is a schematic cross-sectional view taken along line I-I' shown in

[0037] Referring to Figures 1 to 3 , a display device 100 according to an embodiment of the present disclosure may include: a substrate 110 including a plurality of pixels P each having a plurality of sub-pixels SP; a pattern portion 120 disposed on the substrate 110 and formed to be recessed in a non-light-emitting area NEA between the plurality of sub-pixels SP; and a reflection portion 130 disposed to be inclined on the pattern portion 120.

[0038] Each of the plurality of sub-pixels SP may include a plurality of concave portions 140 disposed in a light-emitting region EA adjacent to a non-light-emitting region NEA, and a pixel electrode 114 disposed on the plurality of concave portions 140. Here, the distance between the plurality of concave portions 140 and the reflective portion 130 is longer than the distance between the pixel electrode 114 and the reflective portion 130. That is, the plurality of concave portions 140 may be spaced farther from the reflective portion 130 than the edge of the pixel electrode 114.

[0039] In the display device 100 according to an embodiment of the present disclosure, the plurality of concave portions 140 having a lens shape are spaced farther from the reflective portion 130 disposed in the non-light-emitting region NEA than the edge of the pixel electrode 114. Therefore, light emitted from the light-emitting region EA and incident on one of the plurality of concave portions 140 may be refracted by at least one concave portion to form an optical path to the reflective portion 130.

[0040] Therefore, the display device 100 according to an embodiment of the present disclosure may allow the light refracted by at least one concave portion 140 to be emitted in the front direction of the substrate 110 ( Figure 3 the Z-axis direction in ) through the reflective portion 130 disposed obliquely with respect to the non-light-emitting region NEA, thereby improving the light extraction efficiency.

[0041] The light extraction efficiency may refer to Figure 3 the light extraction efficiency of the front extraction light L1, the inclined extraction light L2 reflected by the reflective portion 130 and emitted in the inclined direction toward the light-emitting region EA, and the direct light L3 not reflected by the reflective portion 130 and emitted to the lower surface of the substrate 110 through the concave portion 140 as shown. The front extraction light L1 according to an example may be light emitted in a direction perpendicular to the upper surface (or lower surface) of the substrate 110.

[0042] On the other hand, as Figure 3 shown, the display device 100 according to an embodiment of the present disclosure may have light extraction even in the non-light-emitting region NEA through the plurality of concave portions 140 and the reflective portion 130. Therefore, compared with a display device without a reflective portion, the same luminous efficiency may be achieved with low power, or the luminous efficiency may be further improved, resulting in lower overall power consumption.

[0043] Hereinafter, with reference to Figures 1 to 3 , the display device 100 according to an embodiment of the present specification will be described in more detail.

[0044] Each of a plurality of sub-pixels SP according to an example may include a light-emitting area EA, a non-light-emitting area NEA adjacent to the light-emitting area EA, a plurality of concave portions 140 overlapping with the light-emitting area EA, and a pixel electrode 114 disposed on the plurality of concave portions 140.

[0045] The light-emitting area EA is an area that emits light and may be included in the display area DA. The non-light-emitting area NEA is an area that does not emit light and may be an area adjacent to the light-emitting area EA. The non-light-emitting area NEA may be arranged to surround the light-emitting area EA. The non-light-emitting area NEA may be referred to as a peripheral area. The reflecting portion 130 may be arranged to be adjacent to (or face) the plurality of concave portions 140 in the non-light-emitting area NEA and spaced apart from the light-emitting area EA.

[0046] Therefore, in the display device 100 according to an embodiment of the present disclosure, since the reflecting portion 130 disposed in the non-light-emitting area NEA can reflect the light emitted from the light-emitting area EA and directed to an adjacent sub-pixel toward the sub-pixel SP for emitting light, the light efficiency (or light extraction efficiency) of the sub-pixel SP for emitting light can be improved.

[0047] The non-light-emitting area NEA according to an example may include a first area A1 adjacent to the light-emitting area EA and a second area A2 adjacent to the first area A1 and spaced apart from the light-emitting area EA. The first area A1 and the second area A2 according to an example may be areas without dams where no dams are provided.

[0048] The pattern portion 120 according to an example may be formed to be recessed into the non-light-emitting area NEA. For example, the pattern portion 120 may be formed to be recessed into the coating layer 113 ( Figure 3 shown in) on the substrate 110. The pattern portion 120 may be arranged to be spaced apart from the light-emitting area EA. The coating layer 113 according to an example may include a first layer 1131 and a second layer 1132 disposed on the first layer 1131. The pattern portion 120 may be formed by patterning and removing a part of the second layer 1132 included in the coating layer 113. Therefore, the pattern portion 120 may be represented by grooves, slits, depressions, trenches, coating layer slits, and coating layer trenches.

[0049] The pattern portion 120 according to an example may be arranged to surround the light-emitting area EA in the form of a slit or a trench. For example, the width of the pattern portion 120 may be formed to decrease in a direction from the reflecting portion 130 toward the substrate 110 (or in a direction from the pixel electrode 114 toward the substrate 110). As Figure 3As shown, the pattern portion 120 may include an inclined surface 120s formed in the second region A2 and a bottom surface 120b extending from the inclined surface 120s and arranged parallel to the upper surface of the substrate 110. The inclined surface 120s may be the inclined surface of the second layer 1132. The bottom surface 120b may be a part of the upper surface 1131a (or flat surface 1131a) of the first layer 1131.

[0050] Meanwhile, as Figure 3 shown, the pattern portion 120 may include, but is not necessarily limited to, the inclined surface 120s of the second layer 1132 and the bottom surface 120b of the first layer 1131. In another example, the pattern portion 120 may be formed only on the second layer 1132. In this case, the inclined surface of the pattern portion 120 may be the inclined surface of the second layer 1132, and the bottom surface of the pattern portion 120 may be the bottom surface of the second layer 1132.

[0051] According to an example, the reflection portion 130 may be formed to be inclined (or recessed) along the contour of the pattern portion 120 formed as the recessed non-light-emitting region NEA, so as to be formed as the recessed non-light-emitting region NEA. The reflection portion 130 may be made of a material capable of reflecting light, and may reflect the light emitted from the light-emitting region EA and guided to adjacent sub-pixels SP back toward the light-emitting region EA for emitting light. As Figure 3 shown, since the reflection portion 130 is arranged to be inclined on the pattern portion 120 while surrounding the light-emitting region EA, the reflection portion 130 may be represented by terms such as a side reflection portion or an inclined reflection portion.

[0052] On the other hand, the display device 100 according to an embodiment of the present disclosure may be implemented as a bottom emission type in which the light emitted from the light-emitting region EA is emitted through the lower surface of the substrate 110. Therefore, in the display device 100 according to an exemplary embodiment of the present disclosure, the extracted light emitted through the lower surface of the substrate 110 may be a combination of direct light L3 emitted from the light-emitting region EA and directly emitted to the lower surface of the substrate 110 through at least one of the plurality of concave portions 140 and reflected light that is emitted from the light-emitting region EA, guided to adjacent sub-pixels SP, reflected on the reflection portion 130, and emitted to the lower surface of the substrate 110. The above-mentioned front extraction light L1 and inclined extraction light L2 may be included in the reflected light. Therefore, compared with a display device that does not include a reflection portion 130 arranged to be inclined toward the non-light-emitting region NEA, the display device 100 according to an embodiment of the present disclosure may have improved light extraction efficiency.

[0053] In the case of a general display device without a reflective portion, in order to improve light extraction efficiency, a plurality of lenses (or a plurality of concave portions) are arranged to overlap the edge (or end) of the light-emitting region, that is, the pixel electrode. On the contrary, the display device 100 according to an embodiment of the present disclosure has the following structural features: wherein, the distance D2 between the plurality of concave portions 140 (or the outermost concave portion provided at the outermost edge of the plurality of concave portions 140) and the reflective portion 130 is longer than the distance D1 between the pixel electrode 114 (or the edge (or end) of the pixel electrode 114) and the reflective portion 130. That is to say, the outermost concave portion 140 among the plurality of concave portions 140 can be spaced apart from the edge of the pixel electrode 114. For example, the outermost concave portion 140 can be arranged to be spaced farther from the reflective portion 130 toward the central portion of the pixel electrode 114 than toward the edge of the pixel electrode 114.

[0054] The reason why the display device 100 according to an embodiment of the present disclosure has such a structural feature is that at least one of the plurality of concave portions 140 refracts the light incident from the light-emitting region EA to form an optical path toward the reflective portion 130, so that the light can also be extracted from the non-light-emitting region NEA, resulting in higher light extraction efficiency compared with a typical display device without a reflective portion.

[0055] In addition, as Figure 3 shown, in the display device 100 according to an embodiment of the present disclosure, the plurality of concave portions 140 (or the outermost concave portion provided among the plurality of recesses) are spaced apart from the reflective portion 130 by a distance D2, the pixel electrode 114 (or the edge of the pixel electrode 114) is spaced apart from the reflective portion 130 by a distance D1, and the distance D2 between the plurality of concave portions 140 and the reflective portion 130 is set to be longer than the distance D1 between the pixel electrode 114 and the reflective portion 130. Therefore, after the light refracted by the outermost concave portion 140 (or the outermost concave portion provided among the plurality of concave portions 140) is totally reflected from the upper surface 1131a of the first layer 1131 (or the interface between the first layer 1131 and the second layer 1132), the light refracted by the outermost concave portion 140 (or the outermost concave portion provided among the plurality of concave portions 140) can be reflected by the reflective portion 130 and emitted as front extraction light L1. In other words, the display device 100 according to an embodiment of the present disclosure can have improved light extraction efficiency through light refraction by the plurality of concave portions 140, total reflection from the upper surface 1131a of the first layer 1131 (or the interface between the first layer 1131 and the second layer 1132), and reflection by the reflective portion 130 inclined in the non-light-emitting region NEA.

[0056] Therefore, the display device 100 according to an embodiment of the present disclosure is configured such that the shortest horizontal distance PHL between the reflection part 130 (or the highest point of the lower surface 130b of the reflection part 130, i.e., P2) and the edge of the upper surface 1131a of the first layer 1131 (refer to Figure 3 the left end of the upper surface 1131a of the first layer 1131 (i.e., P1) adjacent to the rightmost outer concave part 140) satisfies PHL = h * tan(2α). Therefore, the light refracted by at least one of the concave parts 140 can be configured to be reflected by the reflection part 130 after being totally reflected by the upper surface 1131a of the first layer 1131 (or the interface between the first layer 1131 and the second layer 1132). This will be described in more detail later.

[0057] In addition, the display device 100 according to an embodiment of the present disclosure can be configured to optimally have the aspect ratio (or the optimal aspect ratio) of each of the plurality of concave parts 140. Therefore, the light with a large light intensity among the light incident on one of the plurality of concave parts 140 can be refracted toward the reflection part 130. This is because the greater the light intensity incident on the reflection part 130, the greater the amount of forward-extracted light L1 can be increased, thereby improving the overall light extraction efficiency. Therefore, the inventors of the display device 100 according to an embodiment of the present specification simulated the intensity of the refracted light reaching the reflection part 130 through the concave parts 140 with various aspect ratios, and thus derived the aspect ratio of the concave part 140 such that the refracted light having a value greater than or equal to 90% of the intensity of the refracted light with the maximum value reaches the reflection part 130. This will be described by explaining the overall structure of the display device 100 followed by a mathematical expression.

[0058] Refer to Figure 1 and Figure 2 , the display device 100 according to an embodiment of the present disclosure may further include a display panel, a plurality of concave parts 140, a source driver integrated circuit (hereinafter referred to as "IC") 150, a flexible film 160, a circuit board 170, and a timing control unit 180. Herein, the display panel includes a gate driver GD, and the plurality of concave parts 140 overlap with the light-emitting region EA.

[0059] The display panel may include a substrate 110 and a counter substrate 200 ( Figure 3 as shown in

[0060] The substrate 110 may include thin-film transistors and may be a transistor array substrate, a lower substrate, a base substrate, or a first substrate. The substrate 110 may be a transparent glass substrate or a transparent plastic substrate. The substrate 110 may include a display area DA and a non-display area NDA.

[0061] The display area DA is the area for displaying an image, and can be a pixel array area, an active area, a pixel array unit, a display unit, or a screen. For example, the display area DA can be set at the central portion of the display panel. The display area DA can include a plurality of pixels P.

[0062] The opposing substrate 200 can encapsulate (or seal) the display area DA disposed on the substrate 110. For example, the opposing substrate 200 can be bonded to the substrate 110 via an adhesive member (or a transparent adhesive). The opposing substrate 200 can be an upper substrate, a second substrate, or a packaging substrate.

[0063] The gate driver GD supplies a gate signal to the gate lines according to the gate control signal input from the timing controller 190. As Figure 1 shown, the gate driver GD can be formed on one side of the light-emitting area EA or in the non-light-emitting area NEA outside both sides of the light-emitting area EA in a gate driver in panel (GIP) method.

[0064] The non-display area NDA is the area where no image is displayed, and can be a peripheral area, a signal supply area, a non-active area, or a border area. The non-display area NDA can be configured to be near the display area DA. That is, the non-display area NDA can be set to surround the display area DA.

[0065] A pad area PA can be provided in the non-display area NDA. The pad area PA can supply power and / or signals for outputting an image to the pixels P disposed in the display area DA. Referring to Figure 1 , the pad area PA can be provided above the display area DA.

[0066] The source driver IC 150 receives digital video data and a source control signal from the timing controller 180. The source driver IC 150 converts the digital video data into an analog data voltage according to the source control signal, and supplies the analog data voltage to the data lines. When the source driver IC 150 is manufactured as a driving chip, the source driver IC 150 can be encapsulated in the flexible film 160 in a chip on film (COF) method or a chip on plastic (COP) method.

[0067] Pads such as data pads can be formed in the non-display area NDA of the display panel. Wires connecting the pads to the source driver IC 150 and wires connecting the pads to the wires of the circuit board 170 can be formed in the flexible film 160. The flexible film 160 can be attached to the pads by using an anisotropic conductive film, whereby the pads can be connected to the wires of the flexible film 160.

[0068] The circuit board 170 can be attached to the flexible film 160. A plurality of circuits implemented as drive chips can be encapsulated in the circuit board 170. For example, the timing controller 180 can be encapsulated in the circuit board 170. The circuit board 170 can be a printed circuit board or a flexible printed circuit board.

[0069] The timing controller 180 receives digital video data and timing signals from an external system board through the cable of the circuit board 170. The timing controller 180 generates a gate control signal for controlling the operation timing of the gate driver GD and a source control signal for controlling the source driver IC 150 based on the timing signals. The timing controller 180 supplies the gate control signal to the gate driver GD and supplies the source control signal to the source driver IC 150.

[0070] Referring to Figure 2 , the substrate 110 according to the example can include a light-emitting region EA and a non-light-emitting region NEA.

[0071] The light-emitting region EA can refer to a region from which light is emitted. A light-emitting element layer E including a pixel electrode 114, an organic light-emitting layer 116, and a reflective electrode 117 can be provided in the light-emitting region EA. When an electric field is formed between the pixel electrode 114 and the reflective electrode 117, the organic light-emitting layer 116 in the light-emitting region EA can emit light.

[0072] On the other hand, the light-emitting region EA can have the same or a similar shape as the shape of the pixel electrode 114. This is because light can be emitted from the organic light-emitting layer 116 according to the formation of the electric field between the pixel electrode 114 and the reflective electrode 117. Since the region where light is emitted is the light-emitting region EA, the light-emitting region EA can be formed along the shape of the pixel electrode 114. According to an example, the pattern portion 120 is provided to surround the light-emitting region EA, and thus, the pattern portion 120 can be formed along the shape of the pixel electrode 114.

[0073] As Figure 3As shown, a part of the light emitted from the organic light-emitting layer 116 can be wave-guided by being totally reflected due to the difference in refractive index between the organic light-emitting layer 116 and the reflective electrode 117 on the organic light-emitting layer 116 and the difference in refractive index between the organic light-emitting layer 116 and the pixel electrode 114 below the organic light-emitting layer 116. The wave-guided light can form an optical path toward adjacent sub-pixels along the interface of the organic light-emitting layer 116. In a display device according to an embodiment of the present disclosure, the reflecting portion 130 may be disposed between the sub-pixels SP to reflect the light guided to the adjacent sub-pixels toward the sub-pixel for emitting light. Therefore, the display device 100 according to an embodiment of the present disclosure can improve the light efficiency of the sub-pixel for emitting light by extracting the light dissipated by wave-guiding through the reflecting portion 130. In addition, in the display device 100 according to an embodiment of the present disclosure, the reflecting portion 130 disposed between the sub-pixels SP can prevent color mixing caused by wave-guiding.

[0074] For example, the light can be wave-guided and extinguished, and the display device 100 according to an embodiment of the present disclosure can be capable of emitting the possibly extinguished light in the form of reflected light (or obliquely extracted light L2) toward the emitting sub-pixel SP through the reflecting portion 130, thereby improving the light efficiency.

[0075] In addition, the display device 100 according to an embodiment of the present disclosure can be capable of emitting the light that may cause mixing in the form of reflected light (or obliquely extracted light L2) toward the emitting sub-pixel SP through the reflecting portion 130, so that the light efficiency can be maximized.

[0076] Therefore, the display device 100 according to an embodiment of the present disclosure can have improved overall light efficiency while preventing mixing with adjacent sub-pixels SP via the reflecting portion 130.

[0077] Return reference Figure 2 , according to the example, the light-emitting region EA may include a gate line, a data line, a pixel driving power line, and a plurality of pixels P. Each of the plurality of pixels P may include a plurality of sub-pixels SP that may be defined by the gate line and the data line.

[0078] Meanwhile, at least four sub-pixels among the plurality of sub-pixels SP that are set to emit different colors and are set adjacent to each other may constitute a pixel P (or unit pixel). A pixel P may include, but is not limited to, a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel. A pixel P may include three sub-pixels SP that are set to emit light of different colors and are set adjacent to each other. For example, a pixel P may include a red sub-pixel, a green sub-pixel, and a blue sub-pixel.

[0079] Each of the plurality of sub-pixels SP includes a thin film transistor and a light-emitting element layer E connected to the thin film transistor. Each of the plurality of sub-pixels may include a light-emitting layer (or an organic light-emitting layer) interposed between a pixel electrode and a reflective electrode.

[0080] The light-emitting layers respectively provided in the plurality of sub-pixels SP may emit light of different colors separately or emit white light together. Since the light-emitting layers of each of the plurality of sub-pixels SP emit white light together, each of the red sub-pixel, the green sub-pixel, and the blue sub-pixel may include a color filter CF (or a wavelength conversion member CF) for converting the white light into light of their respective different colors. In this case, the white sub-pixel may not include a color filter.

[0081] In the display device 100 according to an embodiment of the present disclosure, the region where the red color filter is provided may be a red sub-pixel or a first sub-pixel, the region where the green color filter is provided may be a green sub-pixel or a second sub-pixel, the region where the blue color filter is provided may be a blue sub-pixel or a third sub-pixel, and the region where no color filter is provided may be a white sub-pixel or a fourth sub-pixel.

[0082] When a gate signal is input from a gate line by using a thin film transistor, each of the sub-pixels SP supplies a predetermined current to the organic light-emitting element according to the data voltage of the data line. To this end, the light-emitting layer of each of the sub-pixels may emit light having a predetermined brightness according to the predetermined current.

[0083] According to an example, the plurality of sub-pixels SP may be arranged adjacent to each other in a first direction (X-axis direction). The first direction (X-axis direction) may be a horizontal direction based on Figure 1 . The horizontal direction may be the direction in which the gate lines are provided.

[0084] A second direction (Y-axis direction) is a direction crossing the first direction (X-axis direction), and may be a vertical direction based on Figure 1 . The vertical direction may be the direction in which the data lines are provided.

[0085] A third direction (Z-axis direction) is a direction crossing each of the first direction (X-axis direction) and the second direction (Y-axis direction), and may be the thickness direction of the display device 100.

[0086] A plurality of sub-pixels SP may include a first sub-pixel SP1, a second sub-pixel SP2, a third sub-pixel SP3, and a fourth sub-pixel SP4 that are arranged adjacent to each other in a first direction (X-axis direction). For example, the first sub-pixel SP1 may be a red sub-pixel, the second sub-pixel SP2 may be a green sub-pixel, the third sub-pixel SP3 may be a blue sub-pixel, and the fourth sub-pixel SP4 may be a white sub-pixel, but is not limited thereto. However, the arrangement order of the first sub-pixel SP1, the second sub-pixel SP2, the third sub-pixel SP3, and the fourth sub-pixel SP4 may be changed.

[0087] Each of the first sub-pixel SP1 to the fourth sub-pixel SP4 may include a light-emitting region EA and a circuit region. The light-emitting region EA may be provided on one side (or upper side) of the sub-pixel region, and the circuit region may be provided on the other side (or lower side) of the sub-pixel region. For example, the circuit region may be provided below the light-emitting region EA based on a second direction (Y-axis direction). The light-emitting regions EA of the first sub-pixel SP1 to the fourth sub-pixel SP4 may have the same size (or area) as each other, or may have different sizes (or areas) from each other.

[0088] The first sub-pixel SP1 to the fourth sub-pixel SP4 may be arranged adjacent to each other along the first direction (X-axis direction). For example, two data lines extending along the second direction (Y-axis direction) may be provided parallel to each other between the first sub-pixel SP1 and the second sub-pixel SP2 and between the third sub-pixel SP3 and the fourth sub-pixel SP4. A pixel power line extending along the first direction (X-axis direction) may be provided between the light-emitting region EA and the circuit region of each of the first sub-pixel SP1 to the fourth sub-pixel SP4. A gate line and a sense line may be provided below the circuit region. A pixel power line EVDD ( Figure 2 shown in) may be provided on one side of the first sub-pixel SP1 or the fourth sub-pixel SP4. A reference line extending along the second direction (Y-axis direction) may be provided between the second sub-pixel SP2 and the third sub-pixel SP3. The reference line RL may be used as a sense line for sensing a change in characteristics of a driving thin-film transistor provided in the circuit region and / or a change in characteristics of a light-emitting element layer from the outside in a sense driving mode of the pixel P. At least a part of the reference line RL according to an example may overlap with the pattern portion 120.

[0089] In one example, the data line is used to supply a data signal to each of the plurality of sub-pixels SP to drive each of the plurality of sub-pixels SP. For example, the data line may include a first data line DL1 for driving the first sub-pixel SP1, a second data line DL2 for driving the second sub-pixel SP2, a third data line DL3 for driving the third sub-pixel SP3, and a fourth data line DL4 for driving the fourth sub-pixel SP4.

[0090] In the display device 100 according to an embodiment of the present disclosure, a data line, for example, the first data line DL1, may be arranged not to overlap with the light-emitting region EA and the reflection part 130 (or the reflection part 117a). Herein, the reflection part 130 is provided on the pattern part 120. For example, as Figure 3 shown, the first data line DL1 may be arranged to overlap with the first region A1. Therefore, it is possible to prevent the display device 100 according to an embodiment of the present disclosure from reducing the light extraction efficiency, because the first data line DL1 does not block (or interfere with) the light reflected by the reflection part 130 (or the reflection part 117a). The second data line DL2, the third data line DL3, and the fourth data line DL4 may be arranged in the first region A1 of the corresponding sub-pixel (for example, the first data line DL1) such that the light-emitting region EA and the reflection part 117a of the corresponding sub-pixel do not overlap in the third direction (Z-axis direction). Therefore, in the display device 100 according to an embodiment of the present disclosure, the data lines DL1, DL2, DL3, and DL4 may have a structural feature of not overlapping with the pattern part 120.

[0091] In the display device 100 according to an embodiment of the present disclosure, each of the data lines DL1, DL2, DL3, and DL4 may extend between a plurality of sub-pixels SP arranged in the first direction (X-axis direction) along a second direction (Y-axis direction) intersecting the first direction (X-axis direction). The pattern part 120 according to an example may partially overlap with the data lines DL1, DL2, DL3, and DL4 in the first direction (X-axis direction) and the second direction (Y-axis direction), as Figure 2 shown. As Figure 2 shown, the pattern part 120 is arranged to surround most of the light-emitting region EA.

[0092] Meanwhile, since the pixel power wiring EVDD and the reference line RL each have a wide width compared to the data line, they may be arranged to overlap not only with the first region A1 but also up to the second region A2. Therefore, in the display device 100 according to an embodiment of the present disclosure, each of the pixel power wiring EVDD and the reference line RL may have a structure that partially overlaps with the pattern part 120.

[0093] In the display device 100 according to an embodiment of the present disclosure, each of the plurality of sub-pixels SP may include a plurality of concave parts 140. The plurality of concave parts 140 may be formed on the coating layer 113 ( Figure 3as shown in [Figure] to overlap with the light-emitting region EA of the sub-pixel. By forming a plurality of concave portions 140 on the coating layer 113 of the light-emitting region EA to have a curved (or uneven) shape, the plurality of concave portions 140 change the traveling path of the light emitted from the light-emitting element layer E to improve the light extraction efficiency. For example, the plurality of concave portions 140 may refract the light emitted from the organic light-emitting layer 116 toward the reflecting portion 130 (or the reflecting portion 117a) on the pattern portion 120. For example, the plurality of concave portions 140 may be a non-planar portion, an irregular pattern portion, a microlens portion, or a light-scattering pattern portion.

[0094] The plurality of concave portions 140 may be formed to be recessed inside the coating layer 113. For example, the plurality of concave portions 140 may be provided by forming the upper surface of the first layer 1131 included in the coating layer 113 to have a plurality of recesses. Accordingly, the first layer 1131 may include the plurality of concave portions 140. The first layer 1131 may be disposed between the substrate 110 and the light-emitting element layer E in the third direction (Z-axis direction). The concave portion 140 may be disposed adjacent to the pattern portion 120 in the first direction (X-axis direction).

[0095] A second layer 1132 of the coating layer 113 may be disposed between the first layer 1131 and the light-emitting element layer E (or Figure 3 the pixel electrode 114 as shown in [Figure]). According to an example, the second layer 1132 may be formed to be wider than the pixel electrode 114 in the first direction (X-axis direction). Accordingly, a part of the second layer 1132 may overlap with the light-emitting region EA, and the remaining part may partially overlap with the first region A1 and the second region A2 of the non-light-emitting region NEA. That is, as Figure 3 shown, the second layer 1132 may extend from the light-emitting region EA to a part of the second region A2 and partially overlap on the second region A2. Since the upper surface 1132a of the second layer 1132 is provided to have a flat surface, the pixel electrode 114 disposed on the upper surface 1132a of the second layer 1132 may also be provided to have a flat surface. The organic light-emitting layer 116 may be disposed on the second layer 1132.

[0096] Meanwhile, the refractive index of the second layer 1132 may be greater than the refractive index of the first layer 1131. Accordingly, as Figure 3As shown, due to the difference in refractive index between the second layer 1132 and the first layer 1131 of the plurality of concave portions 140, the path of the light emitted from the light-emitting layer 116 and guided toward the substrate 110 can be changed toward the reflecting portion 130 (or the reflecting portion 117a). Accordingly, the light guided to the reflecting portion 130 by the plurality of concave portions 140 can be reflected by the reflecting portion 130 and guided to the light-emitting area EA of the sub-pixel SP, or can be guided from the non-light-emitting area NEA in the form of the front-extracted light L1. Hereinafter, the light reflected by the reflecting portion 130 and emitted toward the substrate 110 will be defined as the reflected light.

[0097] As Figure 3 shown, the reflected light may include first reflected light L1 (or front-extracted light L1) (or substrate-mode extracted light L1), which is emitted from the organic light-emitting layer 116, refracted by at least one of the plurality of concave portions 140, and then totally reflected from the interface between the flat surface 1131a (or upper surface 1131a) of the first layer 1131 and the second layer 1132, reflected from the reflecting portion 130, and guided toward the substrate 110. In addition, the reflected light may include second reflected light L2 (or obliquely extracted light L2) (or WG-mode extracted light L2), which is emitted from the organic light-emitting layer 116, waveguide-guided after being totally reflected between the pixel electrode 114 and the reflecting electrode 117 (and / or totally reflected between the reflecting electrode 117 and the second layer 1132), refracted by at least one of the plurality of concave portions 140, and then totally reflected from the interface between the flat surface 1131a (or upper surface 1131a) of the first layer 1131 and the second layer 1132, and reflected from the reflecting portion 130 and guided toward the substrate 110. Here, the flat (upper) surface 1131a of the first layer 1131 may be a flat surface arranged parallel to the substrate 110 (or the upper surface of the substrate 110). As Figure 3 shown, the flat (upper) surface 1131a of the first layer 1131 may be arranged closer to the substrate 110 than the plurality of concave portions 140.

[0098] As Figure 3 shown, the first reflected light L1 according to the example may be emitted from the non-light-emitting area NEA, and the second reflected light L2 may be emitted from the light-emitting area EA. That is, the first reflected light L1 may be emitted from the non-light-emitting area NEA or the surrounding area. This is because the reflecting portion 130 (or the reflecting portion 117a) provided on the pattern portion 120 is inclined toward the non-light-emitting area NEA. However, not limited thereto, the second reflected light L2 may be emitted from the non-light-emitting area NEA according to the angle at which it is incident on the reflecting portion 130.

[0099] On the other hand, the display device 100 according to an embodiment of the present disclosure may further include light that is not reflected by the reflection portion 130 and is guided to the substrate 110 through the plurality of concave portions 140. For example, as shown by the dashed line in Figure 3 , the light emitted from the organic light-emitting layer 116 and incident on one of the plurality of concave portions 140 may further include direct light L3, which is refracted at the periphery of the concave portion 140 (or at the interface between the first layer 1131 and the second layer 1132 forming the concave portion 140) and emitted onto the substrate 110. Therefore, the display device 100 according to an embodiment of the present disclosure can improve the overall light extraction efficiency through the plurality of concave portions 140 and the reflection portion 130.

[0100] In the display device 100 according to an embodiment of the present disclosure, since the pattern portion 120 is disposed to surround the light-emitting region EA, at least a part of the reflection portion 130 on the pattern portion 120 may be disposed to surround the light-emitting region EA. Therefore, the reflected light can be emitted from a position spaced apart from the light-emitting region EA or from the light-emitting region EA toward the substrate 110 while surrounding at least a part of the light-emitting region EA. Therefore, in the display device 100 according to an embodiment of the present disclosure, since the light dissipated through the waveguide (or optical waveguide) and / or the light dissipated through the total internal reflection at the interface can be emitted from the non-light-emitting region NEA in the form of reflected light through the reflection portion 130 surrounding at least a part of the light-emitting region EA, the light extraction efficiency can be improved and the overall light-emitting efficiency can be improved.

[0101] Hereinafter, the structure of each of the plurality of sub-pixels SP will be described in detail.

[0102] Figure 4 is a schematic cross-sectional view taken along the line II-II’ shown in Figure 2 .

[0103] Referring to Figure 4 , the display device 100 according to an embodiment of the present disclosure may further include a buffer layer BL, a circuit element layer 111, a thin-film transistor 112, a pixel electrode 114, a bank 115, an organic light-emitting layer 116, a reflective electrode 117, a encapsulation layer 118, and a color filter CF.

[0104] More specifically, each of the sub-pixels SP according to one embodiment may include: a circuit element layer 111 disposed on the upper surface of the buffer layer BL, the circuit element layer 111 including a gate insulating layer 111a, an interlayer insulating layer 111b, and a passivation layer 111c; a coating layer 113 disposed on the circuit element layer 111; a pixel electrode 114 disposed on the coating layer 113; a bank 115 covering one edge of the pixel electrode 114; an organic light-emitting layer 116 on the pixel electrode 114 and the bank 115; a reflective electrode 117 on the organic light-emitting layer 116; and a encapsulation layer 118 on the reflective electrode 117.

[0105] The circuit element layer 111 may be provided with a thin film transistor 112 for driving each of the plurality of sub-pixels SP. The circuit element layer 111 may be expressed in terms of an inorganic film layer. The buffer layer BL may be included in the circuit element layer 111 together with the gate insulating layer 111a, the interlayer insulating layer 111b, and the passivation layer 111c. The pixel electrode 114, the organic light-emitting layer 116, and the reflective electrode 117 may be included in the light-emitting element layer E.

[0106] The buffer layer BL may be formed between the substrate 110 and the gate insulating layer 111a to protect the thin film transistor 112. The buffer layer BL may be disposed on the entire surface (or front surface) of the substrate 110. A pixel power line EVDD for pixel driving may be disposed between the buffer layer BL and the substrate 110. The pixel power line EVDD may be disposed under the bank 115 while being spaced apart from the thin film transistor 112. The buffer layer BL may be used to block the diffusion of materials contained in the substrate 110 into the transistor layer during the high-temperature process of the thin film transistor manufacturing process. Optionally, the buffer layer BL may be omitted in some cases.

[0107] The thin film transistor 112 (or driving transistor) according to the example may include an active layer 112a, a gate electrode 112b, a source electrode 112c, and a drain electrode 112d.

[0108] The active layer 112a may include a channel region, a drain region, and a source region formed in the thin film transistor region of the circuit region of the sub-pixel SP. The drain region and the source region may be spaced apart from each other by the channel region disposed therebetween.

[0109] The active layer 112a may be formed of a semiconductor material based on any one of amorphous silicon, polycrystalline silicon, oxide, and organic material.

[0110] The gate insulating layer 111a may be formed on the channel region of the active layer 112a. As an example, the gate insulating layer 111a may be formed in an island shape only on the channel region of the active layer 112a, or may be formed on the entire front surface of the first substrate 110 including the active layer 112a or the buffer layer BL.

[0111] The gate electrode 112b may be formed on the gate insulating layer 111a to overlap with the channel region of the active layer 112a.

[0112] The interlayer insulating layer 111b may be formed on the gate electrode 112b and the drain region and source region of the active layer 112a. As in Figure 4 the interlayer insulating layer 111b may be formed in the circuit region and the entire light-emitting region, and in the light-emitting region, light is emitted to the sub-pixel SP. However, the embodiments of the present disclosure are not limited thereto, the interlayer insulating layer 111b may be patterned between the drain electrode 112d and the gate electrode 112b and the drain region of the active layer 112a, and may be arranged in an island shape, and in addition, the interlayer insulating layer 111b may also be patterned between the source electrode 112c and the gate electrode 112b and the source region of the active layer 112a.

[0113] The source electrode 112c may be electrically connected to the source region of the active layer 112a through a source contact hole provided in the interlayer insulating layer 111b overlapping with the source region of the active layer 112a. The drain electrode 112d may be electrically connected to the drain region of the active layer 112a through a drain contact hole provided in the interlayer insulating layer 111b overlapping with the drain region of the active layer 112a.

[0114] The drain electrode 112d and the source electrode 112c may be made of the same metal material. For example, each of the drain electrode 112d and the source electrode 112c may be made of a single metal layer, a single-layer alloy, or a multi-layer of two or more layers that is the same as or different from the layer of the gate electrode.

[0115] Meanwhile, in the display device 100 according to an embodiment of the present disclosure, the substrate 110 may include a connection region CNA connecting the thin film transistor 112 and the pixel electrode 114. The connection region CNA according to an example is a region connecting the thin film transistor 112 and the pixel electrode 114 in the circuit region CA. As Figure 2As shown, a connection region CNA according to an example can be a region between a light-emitting region EA and a circuit region CA. Since the connection region CNA is a region connecting the thin-film transistor 112 and the pixel electrode 114, the pattern portion 120 may not be formed in the connection region CNA. This is because if the pattern portion 120 is formed in the connection region CNA, due to the step difference of the pattern portion 120, the thickness of the pixel electrode 114 may be thin, which may cause the pixel electrode 114 to short-circuit. Therefore, the display device 100 according to an embodiment of the present disclosure can be configured such that the pattern portion 120 is not formed in the connection region CNA, thereby preventing the connection between the pixel electrode 114 and the thin-film transistor 112 from being weakened.

[0116] In addition, the circuit region may further include a first switching thin-film transistor, a second switching thin-film transistor, and a capacitor provided together with the thin-film transistor 112. Since each of the first switching thin-film transistor and the second switching thin-film transistor is provided on the circuit region of the sub-pixel SP to have the same structure as that of the thin-film transistor 112, its description will be omitted. A capacitor (not shown) may be provided in an overlapping region between the gate electrode 112b and the source electrode 112c of the thin-film transistor 112, where the gate electrode 112b and the source electrode 112c overlap each other, and an interlayer insulating layer 111b is interposed between the gate electrode 112b and the source electrode 112c.

[0117] In addition, in order to prevent the threshold voltage of the thin-film transistor provided in the pixel region from shifting due to light, the display panel or substrate 110 may further include a light-shielding layer (not shown) provided under the active layer 112a of at least one of the thin-film transistor 112, the first switching thin-film transistor, or the second switching thin-film transistor. The light-shielding layer may be provided between the substrate 110 and the active layer 112a to block the light incident on the active layer 112a through the substrate 110, thereby minimizing the change in the threshold voltage of the transistor caused by external light. In addition, since the light-shielding layer is provided between the substrate 110 and the active layer 112a, the thin-film transistor can be prevented from being seen by the user.

[0118] A passivation layer 111c may be provided on the substrate 110 to cover the pixel region. The passivation layer 111c covers the drain electrode 112d, the source electrode 112c, and the gate electrode 112b of the thin-film transistor 112, and the buffer layer BL. A reference line RL may be provided between the passivation layer 111c and the interlayer insulating layer 111b. The reference line RL may be provided at a position symmetric to the light-emitting region EA and the pixel power line EVDD, or at a similar position symmetric to the pixel power line EVDD.

[0119] On the other hand, the display device 100 according to an embodiment of the present disclosure can be configured such that the bank 115 is provided only in the circuit region CA. Thus, as Figure 5 shown, the pixel power line EVDD can be arranged to overlap the bank 115 in the third direction (Z-axis direction), and the reference line RL can be arranged not to overlap the bank 115 in the third direction (Z-axis direction). The reference line RL can be on the same layer as the source electrode 112c and the drain electrode 112d. The passivation layer 111c can be formed over the circuit region and the light-emitting region. The passivation layer 111c can be omitted. The color filter CF can be provided on the passivation layer 111c.

[0120] The coating layer 113 can be provided on the substrate 110 to cover the passivation layer 111c and the color filter CF. When the passivation layer 111c is omitted, the coating layer 113 can be provided on the substrate 110 to cover the circuit region. The coating layer 113 can be formed in the circuit region CA and the light-emitting region EA in which the thin-film transistor 112 is provided. In addition, the coating layer 113 can be formed in other non-display regions NDA and the entire display region DA except for the pad region PA of the non-display region NDA. For example, the coating layer 113 can include an extension portion (or an enlarged portion) extending or expanding from the display region DA to other non-display regions NDA except for the pad region PA. Thus, the coating layer 113 can have a size relatively wider than the size of the display region DA.

[0121] The coating layer 113 according to an example can be formed to have a relatively thick thickness so as to provide a flat surface over the display region DA and the non-display region NDA. For example, the coating layer 113 can be made of an organic material such as photoacrylic, benzocyclobutene, polyimide, and fluororesin.

[0122] The coating layer 113 formed in the display region DA (or the light-emitting region EA) can include a plurality of concave portions 140. The plurality of concave portions 140 can be a structure for increasing the light efficiency of the light-emitting region EA and are formed inside the coating layer 113. Specifically, as Figure 4 shown, the plurality of concave portions 140 can be formed in a recessed shape on the first layer 1131 of the coating layer 113. The plurality of concave portions 140 are arranged to be connected to each other such that a relief shape can be formed in the first layer 1131.

[0123] A second layer 1132 having a refractive index higher than that of the first layer 1131 can be formed on the first layer 1131. The path of the light emitted from the light-emitting element layer E and directed to an adjacent sub-pixel SP can be changed toward the reflection portion 130 according to the difference in refractive index between the second layer 1132 and the first layer 1131. The second layer 1132 can be arranged to cover the relief shape of the first layer 1131, and thus the upper surface 1132a can be arranged to be flat.

[0124] The pixel electrode 114 is formed on the upper surface 1132a of the second layer 1132 such that the pixel electrode 114 can be set to be flat, and the organic light-emitting layer 116 and the reflective electrode 117 formed on the pixel electrode 114 can also be set to be flat. Since the pixel electrode 114, the organic light-emitting layer 116, and the reflective electrode 117, i.e., the light-emitting element layer E, are set to be flat in the light-emitting region EA, the thickness of each of the pixel electrode 114, the organic light-emitting layer 116, and the reflective electrode 117 in the light-emitting region EA can be formed uniformly. Therefore, the organic light-emitting layer 116 can emit light uniformly in the light-emitting region EA without deviation.

[0125] After the first layer 1131 is coated to cover the passivation layer 111c and the color filter CF, a plurality of concave portions 140 can be formed on the first layer 1131 by a photolithography process using a mask having an opening portion and then by a patterning (or etching) or ashing process. The plurality of concave portions 140 can be formed in a region overlapping the color filter CF, or can be formed in a region not overlapping the bank 115 of the non-light-emitting region NEA.

[0126] Return reference Figure 4 , the color filter CF provided in the light-emitting region EA can be disposed between the substrate 110 and the coating layer 113. Therefore, the color filter CF can be disposed between the pixel power line EVDD (e.g., the pixel power line EVDD) and the reflective portion 130, or between the pixel driving line and the pattern portion 120. The color filter CF can include a red color filter (or first color filter) CF1 for converting white light emitted from the organic light-emitting layer 116 into red light, a green color filter (or second color filter) CF2 for converting white light into green light, and a blue color filter (or third color filter) CF3 for converting white light into blue light. The fourth sub-pixel serving as a white sub-pixel may not include a color filter because the organic light-emitting layer 116 emits white light.

[0127] As Figure 3 shown, the display device 100 according to an embodiment of the present disclosure can be set such that color filters having different colors partially overlap each other at the boundary portions of the plurality of sub-pixels SP. In this case, the display device 100 according to an embodiment of the present disclosure can prevent light emitted from each sub-pixel SP from being emitted to an adjacent sub-pixel SP due to the overlapping of the color filters at the boundary portions of the sub-pixels SP, thereby preventing color mixing between the sub-pixels SP.

[0128] Return reference Figure 4, the pixel electrode 114 of the sub-pixel SP may be formed on the coating layer 113. The pixel electrode 114 may be connected to the drain electrode or the source electrode of the thin film transistor 112 through a contact hole passing through the coating layer 113 and the passivation layer 111c. In Figure 4 , the pixel electrode 114 may be set wider than the second layer 1132. However, depending on the cross-sectional position, the pixel electrode 114 may be set narrower than the second layer 1132. For example, as Figure 4 shown, the pixel electrode 114 may be set narrower than the second layer 1132. As Figure 5 shown, when the pixel electrode 114 is set wider than the second layer 1132, the edge portion of the pixel electrode 114 may be connected to the drain electrode or the source electrode in the circuit region CA. In this case, the edge portion of the pixel electrode 114 may be covered by the bank 115. The pixel electrode 114 may be made of at least one of a transparent metal material or a semi-transmissive metal material.

[0129] Since the display device 100 according to an embodiment of the present disclosure is configured as a bottom emission type, the pixel electrode 114 may be formed of a transparent conductive material (or TCO) such as indium tin oxide (ITO) or indium zinc oxide (IZO) that can transmit light, or a semi-transmissive conductive material such as magnesium (Mg), silver (Ag), or an alloy of Mg and Ag.

[0130] Meanwhile, the material constituting the pixel electrode 114 may include MoTi. The pixel electrode 114 may be the first electrode or the anode electrode.

[0131] The bank 115 is a non-light-emitting region, which may be provided on one side of each of the light-emitting portions (or concave portions 140) of each of the plurality of sub-pixels SP. For example, the bank 115 may be provided in the circuit region CA. As Figure 4 shown, the bank 115 may be formed to cover the portion where the edge of each of the pixel electrodes 114 of each of the sub-pixels SP is connected to the thin film transistor 112. That is, the bank 115 may partially cover the pixel electrode 114. Therefore, the bank 115 can prevent the pixel electrode 114 and the reflective electrode 117 from contacting in the circuit region CA. The exposed portion of the pixel electrode 114 not covered by the bank 115 may include a light-emitting portion (or a light-emitting region EA). Such a light-emitting portion may be formed on the plurality of concave portions 140, as Figure 3 shown, so that the light-emitting portion (or the light-emitting region EA) may overlap with the concave portion 140 in the thickness direction (or the third direction (Z-axis direction)) of the substrate 110.

[0132] After the formation of the bank 115, an organic light-emitting layer 116 may be formed to cover the pixel electrode 114 and the bank 115. Accordingly, the bank 115 may be disposed between the pixel electrode 114 and the organic light-emitting layer 116. The bank 115 may be expressed in terms of a pixel defining layer. The bank 115 according to an example may include an organic and / or inorganic material. The bank 115 according to an example may be recessed or inclined along the contour of the pattern portion 120 (or the second layer 1132).

[0133] Referring again to Figure 4 , the organic light-emitting layer 116 may be formed on the pixel electrode 114 and the bank 115. The organic light-emitting layer 116 according to an example may be disposed in the light-emitting region EA and the non-light-emitting region NEA. The organic light-emitting layer 116 may be disposed between the pixel electrode 114 and the reflective electrode 117. Accordingly, when a voltage is applied to each of the pixel electrode 114 and the reflective electrode 117, an electric field is formed between the pixel electrode 114 and the reflective electrode 117. Accordingly, the organic light-emitting layer 116 may emit light. The organic light-emitting layer 116 may be formed of a plurality of sub-pixels SP and a common layer disposed on the bank 115.

[0134] The organic light-emitting layer 116 according to an embodiment may be configured to emit white light. The organic light-emitting layer 116 may include a plurality of stacked layers that emit different colors of light. For example, the organic light-emitting layer 116 may include a first stacked layer, a second stacked layer, and a charge generation layer (CGL) disposed between the first stacked layer and the second stacked layer. The light-emitting layer may be configured to emit white light, and accordingly each of the plurality of sub-pixels SP may include a color filter CF suitable for a corresponding color.

[0135] The first stacked layer may be disposed on the pixel electrode 114, and may be implemented as a structure in which a hole injection layer (HIL), a hole transport layer (HTL), a light-emitting layer (EML(B)), and an electron transport layer (ETL) are stacked in this order.

[0136] The charge generation layer may supply charges to the first stacked layer and the second stacked layer. The charge generation layer may include an N-type charge generation layer for supplying electrons to the first stacked layer and a P-type charge generation layer for supplying holes to the second stacked layer. The N-type charge generation layer may include a metal material as a dopant.

[0137] The second stacked layer may be disposed on the first stacked layer, and may be implemented as a structure in which a hole transport layer (HTL), a yellow-green (YG) light-emitting layer (EML(YG)), and an electron injection layer (EIL) are stacked in this order.

[0138] In the display device 100 according to an embodiment of the present disclosure, since the organic light-emitting layer 116 is provided as a common layer, the first stack, the charge generation layer, and the second stack can all be disposed above the plurality of sub-pixels SP. The organic light-emitting layer 116 according to other examples can be provided in a triple-stack structure or a quadruple-stack structure according to the number of stacked stacks.

[0139] The reflective electrode 117 can be formed on the organic light-emitting layer 116. The reflective electrode 117 can be disposed in the light-emitting region EA and the non-light-emitting region NEA. The reflective electrode 117 according to one example can include a metal material. The reflective electrode 117 can reflect the light emitted from the organic light-emitting layer 116 in the plurality of sub-pixels SP toward the lower surface of the substrate 110. Therefore, the display device 100 according to an embodiment of the present disclosure can be implemented as a bottom-emission type display device.

[0140] The display device 100 according to an embodiment of the present disclosure is of a bottom-emission type and must reflect the light emitted from the light-emitting layer 116 toward the substrate 110, and thus the reflective electrode 117 can be made of a metal material having a high reflectivity. The reflective electrode 117 according to one example can be formed of a stacked structure (Ti / Al / Ti) of metal materials having a high reflectivity such as aluminum and titanium, a stacked structure (ITO / Al / ITO) of aluminum and ITO, an Ag alloy, and a stacked structure (ITO / Ag alloy / ITO) of an Ag alloy and ITO. The Ag alloy can be an alloy such as silver (Ag), palladium (Pd), and copper (Cu). The reflective electrode 117 can be represented by terms such as a second electrode, a cathode electrode, and a counter electrode.

[0141] Meanwhile, in the display device 100 according to an embodiment of the present disclosure, the reflective portion 130 can be a part of the reflective electrode 117. Therefore, the reflective portion 130 can reflect the light guided to an adjacent sub-pixel SP toward the light-emitting region EA of the sub-pixel SP for emitting light. Since the reflective portion 130 is a part of the reflective electrode 117, as Figure 3 shown, the reflective portion 130 can be denoted by the reference numeral 117a. In the present disclosure, the reflective portion 130 can refer to the reflective electrode 117 overlapping the pattern portion 120. In particular, the reflective portion 130 can refer to the reflective electrode 117 that is inclined while overlapping the pattern portion 120. Therefore, the reflective portion 130 can reflect the light guided to an adjacent sub-pixel and / or the light extinguished by total reflection between interfaces to the light-emitting region EA and / or the non-light-emitting region NEA of the emitting sub-pixel SP, as Figure 3 shown.

[0142] The encapsulation layer 118 is formed on the reflective electrode 117. The encapsulation layer 118 is used to prevent oxygen or moisture from penetrating into the organic light-emitting layer 116 and the reflective electrode 117. To this end, the encapsulation layer 118 may include at least one inorganic film and at least one organic film.

[0143] Meanwhile, as Figure 3 shown, the encapsulation layer 118 may be disposed not only in the light-emitting region EA but also in the non-light-emitting region NEA. The encapsulation layer 118 may be disposed between the reflective electrode 117 and the opposing substrate 200.

[0144] Hereinafter, the pattern portion 120 and the reflective portion 130 of the display device 100 according to an embodiment of the present disclosure will be described in more detail with reference to Figure 2 and Figure 3 The display device 100 according to an embodiment of the present disclosure may be configured to have a pattern portion 120 at the periphery of the light-emitting region EA (or non-light-emitting region NEA) and a reflective portion 130 disposed on the pattern portion 120 to prevent a reduction in light extraction efficiency because some of the light emitted from the light-emitting element layer may not be emitted to the outside due to total reflection or the like at the interface between the light-emitting element layer and the electrode. The reflective portion 130 may be disposed obliquely along the contour of the pattern portion 120.

[0145] Referring to

[0146] Referring to Figure 2 , the pattern portion 120 may be recessed in the first layer 1131 of the coating layer 113. The pattern portion 120 may be disposed in the non-light-emitting region NEA, as Figure 2 shown. That is, the pattern portion 120 may be disposed to surround the light-emitting region EA while being adjacent to the plurality of concave portions 140. When the plurality of concave portions 140 are formed in the light-emitting region EA, the pattern portion 120 may be formed together in the non-light-emitting region NEA. The pattern portion 120 may include a bottom surface 120b and an inclined surface 120s.

[0147] According to an embodiment, the bottom surface 120b of the pattern portion 120 is formed as the surface closest to the substrate 110, or may be disposed closer to the substrate 110 (or the upper surface of the substrate) than the pixel electrode 114 (or the lower surface of the pixel electrode 114) in the light-emitting region EA.

[0148] As Figure 3 shown, the bottom surface 120b of the pattern portion 120 (or the flat (upper) surface 1131a of the first layer 1131) may be deeper than the depth (H) of each of the plurality of concave portions 140, Figure 7As shown in [the figure], it is deep. Here, the depth of each of the plurality of concave portions 140 may be the length from the center C of the concave portion 140 to the outer surface of the concave portion 140 in the vertical direction (or the third direction (Z-axis direction)) (or the interface between the first layer 1131 and the second layer 1132). As Figure 3 shown, the flat (upper) surface 1131a of the first layer 1131 may be set closer to the substrate 110 than the plurality of concave portions 140.

[0149] By making the bottom surface 120b of the pattern portion 120 or the flat (upper) surface 1131a of the first layer 1131 deeper than the depth (H, Figure 7 as shown in [the figure]) of each of the plurality of concave portions 140, the light refracted by at least one of the plurality of concave portions 140 can be totally reflected at the interface between the flat (upper) surface 1131a of the first layer 1131 and the second layer 1132, as Figure 3 shown. Therefore, in the display device 100 according to an embodiment of the present disclosure, the plurality of concave portions 140 may be spaced apart from the reflection portion 130 because the amount of the totally reflected light may vary according to the area (or length) of the flat (upper) surface 1131a of the first layer 1131 between the outermost concave portion 140 of the plurality of concave portions 140 and the reflection portion 130.

[0150] For example, the distance by which the plurality of concave portions 140 are spaced apart from the reflection portion 130 may be greater than the distance by which the edge of the pixel electrode 114 is spaced apart from the reflection portion 130. Referring to Figure 3 , if the shortest horizontal distance by which the edge of the pixel electrode 114 and the reflection portion 130 are spaced apart in the first direction (X-axis direction) is referred to as a first horizontal distance D1, the shortest horizontal distance by which the plurality of concave portions 140 and the reflection portion 130 are spaced apart in the first direction (X-axis direction) may be a second horizontal distance D2 that is longer than the first horizontal distance D1. Therefore, the second horizontal distance D2 and the first horizontal distance D1 may have a difference of at least a third horizontal distance D3.

[0151] The display device 100 according to an embodiment of the present disclosure has a plurality of concave portions 140 spaced apart from the reflection electrode 130 by a third horizontal distance D3 farther than the edge of the pixel electrode 114, such that the light refracted by at least one of the concave portions 140 can be totally reflected from the flat (upper) surface 1131a of the first layer 1131. Therefore, the display device 100 according to an embodiment of the present disclosure can improve the light extraction efficiency because the light totally reflected by the flat (upper) surface 1131a of the first layer 1131 can be reflected by the reflection portion 130 provided in the non-light-emitting area NEA and projected toward the substrate 110.

[0152] On the other hand, as Figure 3As shown, the first horizontal distance D1 is the shortest horizontal distance between the edge of the pixel electrode 114 and the reflective portion 130, and can thus be defined as the width of the first region A1 adjacent to the light-emitting region EA.

[0153] Referring again to Figure 3 , when the depth of the pattern portion 120 is lower than the depth of the concave portion 140, the area of the reflective portion 130 that is set to be inclined toward the non-light-emitting region NEA becomes smaller, and thus the light extraction efficiency may decrease. Therefore, the display device 100 according to an embodiment of the present disclosure may be configured such that the depth of the pattern portion 120 is deeper than the depth of the concave portion 140, and thus the light extraction efficiency can be improved by increasing the reflection area of the reflective portion 130.

[0154] The inclined surface 120s of the pattern portion 120 may be provided between the bottom surface 120b and the plurality of concave portions 140. Thus, the inclined surface 120s of the pattern portion 120 may be configured to surround the light-emitting region EA or the plurality of concave portions 140. As Figure 3 shown, the inclined surface 120s may be connected to the bottom surface 120b. The inclined surface 120s may form a predetermined angle with the bottom surface 120b. For example, the angle formed by the inclined surface 120s and the bottom surface 120b may be an obtuse angle. Therefore, the pattern portion 120 may be configured such that the width of the pattern portion 120 decreases from the relative substrate 200 (or the reflective portion 130) toward the substrate 110 (or in the third direction (Z-axis direction)).

[0155] Since the inclined surface 120s and the bottom surface 120b of the pattern portion 120 form an obtuse angle, the organic light-emitting layer 116 and the reflective electrode 117 formed in subsequent processes may be recessed along the contour of the pattern portion 120. Thus, the reflective portion 130 included in the reflective electrode 117 may be recessed (or inclined) and formed on the pattern portion 120 that is recessed (or inclined) and formed in the non-light-emitting region NEA (or the surrounding region).

[0156] As Figure 3 shown, the pattern portion 120 may be configured to surround the light-emitting region EA. Since the pattern portion 120 is configured to surround the light-emitting region EA, at least a part of the reflective portion 130 that is set to be inclined on the pattern portion 120 may be configured to surround the light-emitting region EA. Thus, in the display device 100 according to an embodiment of the present disclosure, since light can be extracted even from the non-light-emitting region NEA near the light-emitting region EA, the overall light efficiency can be improved. Therefore, compared with a general display device that does not have the pattern portion 120 and the reflective portion 130 on the pattern portion 120, the display device 100 according to an embodiment of the present disclosure may have the same or improved light-emitting efficiency even at low power, thereby reducing the overall power consumption.

[0157] In addition, the display device 100 according to an embodiment of the present disclosure can allow the light-emitting element layer E to emit light even at low power, thereby increasing the lifespan of the light-emitting element layer E.

[0158] Returning to Figure 2 , the pattern portion 120 may include a first pattern line 121 disposed between the circuit region CA and the light-emitting region EA along a first direction (X-axis direction) and a second pattern line 122 disposed along a second direction (Y-axis direction) intersecting the first direction (X-axis direction). Referring to Figure 2 , the first pattern line 121 may refer to the pattern portion 120 disposed along the horizontal direction, and the second pattern line 122 may refer to the graphic portion 120 disposed along the vertical direction.

[0159] The first pattern line 121 may include a bottom surface 121b and an inclined surface 121s. The second pattern line 122 may include a bottom surface 122b and an inclined surface 122s. Since each of the bottom surface 121b and the inclined surface 121s of the first pattern line 121 and each of the bottom surface 122b and the inclined surface 122s of the second pattern line 122 are the same as each of the bottom surface 120b and the inclined surface 120s of the pattern portion 120, their descriptions will be replaced by the descriptions of the bottom surface 120b and the inclined surface 120s of the pattern portion 120. The first pattern line 121 and the second pattern line 122 may be connected to one of the non-light-emitting regions NEA (or peripheral regions) to surround the light-emitting region EA.

[0160] The first pattern line 121 may be disposed between sub-pixels SP that emit light of the same color. For example, the first pattern line 121 may be disposed between first sub-pixels SP1 disposed along the second direction (Y-axis direction). Therefore, the first pattern line 121 may be disposed along the first direction (X-axis direction). Conversely, the second pattern line 122 may be disposed between sub-pixels SP that emit light of different colors. For example, the second pattern line 122 may be disposed between a first sub-pixel SP1 that is a red sub-pixel and a second sub-pixel SP2 that is a green pixel. Therefore, the second pattern line 122 may be disposed along the second direction (Y-axis direction).

[0161] Since the second pattern line 122 is disposed between sub-pixels SP that emit light of different colors, the reflection portion 130 on the second pattern line 122 can prevent light of different colors from being emitted to other adjacent sub-pixels SP. Therefore, the display device 100 according to the present disclosure can prevent color mixing (or color distortion) between sub-pixels SP that emit light of different colors, thereby improving color purity.

[0162] In addition, since the second pattern line 122 extends between sub-pixels SP that emit different colors in the second direction (Y-axis direction), the second pattern line 122 may not overlap with the data line (e.g., the first data line DL1) in the second direction (Y-axis direction). On the contrary, the first pattern line 121 extends in the first direction (X-axis direction), so the first pattern line 122 may partially overlap with the data line (e.g., the first data line DL1) in the second direction (Y-axis direction).

[0163] On the other hand, since the pattern portion 120 is formed by patterning the second layer 1132 of the coating layer 113, the end portion 1132b of the second layer 1132 may contact the flat surface 1131a of the first layer 1131, as Figure 3 shown. However, in this case, the end portion 1132b of the second layer 1132 may only contact a part of the flat surface 1131a. This is because if the second layer 1132 covers the entire flat surface 1131a, the depth of the reflection portion 130 formed on the pattern portion 120 may be relatively low, which may reduce the reflection efficiency. Therefore, the display device 100 according to an embodiment of the present disclosure is configured such that the second layer 1132 does not cover the entire flat surface 1131a of the first layer 1131, but only contacts a part of the flat surface 1131a, so that the reflection portion 130 formed in a subsequent process can be formed to be close to the bottom surface 120b, thereby improving the reflection efficiency. As Figure 3 shown, the upper surface 1132a of the second layer 1132 and the end surface 1132b of the second layer 1132 may be connected via the inclined surface 1132c of the second layer 1132. According to an example, the inclined surface 1132c of the second layer 1132 may be arranged to face the reflection portion 130. On the other hand, since the pattern portion 120 is formed by patterning the second layer 1132 of the coating layer 113, the inclined surface 120s of the pattern portion 120 may be the inclined surface 1132c of the second layer 1132.

[0164] Hereinafter, with reference to Figure 5 and Figure 6 , the shortest horizontal distance PHL between the reflection portion 130 (or the lower surface 130b of the reflection portion 130) and the end of the upper surface 1131a of the first layer 1131 will be described in detail.

[0165] Figure 5 is Figure 2 a schematic enlarged plan view of part A shown in Figure 6 and Figure 3 is a schematic enlarged cross-sectional view of part B shown in

[0166] With reference to Figure 5 and Figure 6, in the display device 100 according to an embodiment of the present disclosure, the first layer 1131 may further include an inclined surface 1131b connecting the flat surface 1131a and the plurality of concave portions 140 (or the outermost concave portion 140). The flat surface 1131a of the first layer 1131 and the inclined surface 1131b of the first layer 1131 may be connected at a first point P1. The first point P1 according to the example may be set to overlap with the pixel electrode 114 in the third direction (Z-axis direction), as Figure 6 shown. This is because, by ensuring the length (or area) of the flat surface 1131a of the first layer 1131, the amount of total reflection of the light refracted and incident through the concave portion 140 can be increased. By having a longer length (or area) of the flat surface 1131a of the first layer 1131 on which the light is totally reflected, the amount of light totally reflected by the flat surface 1131a of the first layer 1131 to the reflection portion 130 can be increased, and thus the efficiency of extracting the front light L1 can be improved. Therefore, the display device 100 according to an embodiment of the present disclosure is configured such that the first point P1 overlaps with the pixel electrode 114 in the third direction (Z-axis direction), so that the amount of light totally reflected by the concave portion 140 can be increased, thereby improving the light efficiency.

[0167] Referring to Figure 5 , since the first point P1 is set to overlap with the pixel electrode 114, the first point P1 may be set in a plane that is a structure surrounding the plurality of concave portions 140 between the plurality of concave portions 140 and the edge of the pixel electrode 114. On the other hand, the first data line DL1 may be set to overlap with the first region A1 in the second direction (Y-axis direction) so as not to block the light reflected by the reflection electrode 130 (or the reflection portion 117a) (as Figure 3 shown). That is, the first data line DL1 may be disposed between the pixel electrode 114 and the reflection electrode 130. Therefore, the display device 100 according to an embodiment of the present disclosure can prevent its light extraction efficiency from being reduced by the data line. On the other hand, the first region A1 may refer to a region provided between the light-emitting region EA and the second region A2 or may refer to a region where the horizontal distance between the pixel electrode 114 and the reflection portion 130 is the shortest.

[0168] Referring to Figure 6, the reflective portion 130 may include an upper surface 130a in contact with the encapsulation layer 118 and a lower surface 130b in contact with the organic light-emitting layer 116. For example, the upper surface 130a may be in contact with the encapsulation layer 118 in the second region A2. And the lower surface 130b may be in contact with the organic light-emitting layer 116 in the second region A2. The lower surface 130b of the reflective portion 130 may include the uppermost second point P2 provided on the pattern portion 120. In one example, the second point P2 may be the inflection point of the reflective electrode 117 bent in the pattern portion 120. Alternatively, the second point P2 may be the intersection of the flat lower surface of the reflective electrode 117 (or the extension of the upper surface of the pixel electrode 114) provided in the first region A1 and the lower surface 130b of the reflective electrode 130. A virtual line passing through the second point P2 and parallel to the second direction (Y-axis direction) may be the baseline ML. The baseline ML according to one example may be the baseline separating the first region A1 and the second region A2.

[0169] On the other hand, as Figure 6 shown, the upper surface 130a of the reflective portion 130 may include a third point P3 provided at the lowermost side on the pattern portion 120. In one example, the third point P3 may be the point where the upper surface 130a of the reflective portion 130 is connected to the upper surface of the reflective electrode 117 flatly provided on the pattern portion 120.

[0170] In the display device 100 according to an embodiment of the present disclosure, the non-light-emitting region NEA may include a first region A1 and a second region A2. As Figure 6 shown, the first region A1 may be the region between the edge of the pixel electrode 114 and the second point P2. The first region A1 may be provided adjacent to the light-emitting region EA. The second region A2 may be adjacent to the first region A1 and may be the region between the second point P2 and the third point P3. As Figure 6 shown, the reflective portion 130 may be provided in the second region A2. Therefore, in the display device 100 according to an embodiment of the present disclosure, the light refracted by at least one of the plurality of concave portions 140 and totally reflected by the flat surface 1131a of the first layer 1131 may be reflected by the reflective portion 130 provided in the second region A2 and projected onto the substrate 110.

[0171] On the other hand, in the display device 100 according to an embodiment of the present disclosure, the horizontal distance PHL between the second point P2 and the first point P1 may be set to satisfy PHL = h * tan(2α). Here, the horizontal distance PHL between the second point P2 and the first point P1 may refer to the shortest horizontal distance PHL between the second point P2 and the first point P1 in the first direction (X-axis direction). h may be the thickness of the second layer 1132 provided on the flat surface 1131a of the first layer 1131. α may be the angle between the reflecting portion 130 (or the extension of the lower surface 130b of the reflecting portion 130) and the flat surface 1131a of the first layer 1131 (or the bottom surface 120b of the pattern portion 120).

[0172] Therefore, the display device 100 according to an embodiment of the present disclosure may be configured to have the first layer 1131, the second layer 1132, and the reflecting portion 130 that satisfy the above horizontal distance (PHL). Thus, the light refracted by the concave portion 140 and totally reflected from the flat surface 1131a is reflected by the reflecting portion 130 and guided to the substrate 110. Therefore, in the display device 100 according to an embodiment of the present disclosure, the second point P2 and the first point P1 may be set to have a horizontal distance PHL that satisfies the mathematical expression PHL = h * tan(2α), and the plurality of concave portions 140 (or the outermost concave portion 140) may be arranged to face more inwardly toward the central portion of the pixel electrode 114 than the first point P1. Therefore, the display device 100 according to an embodiment of the present disclosure may be configured to have a structure in which the plurality of concave portions 140 are spaced apart from the reflecting portion 130 by a distance greater than the above horizontal distance PHL.

[0173] Hereinafter, with reference to Figure 7 and Figure 8 , the intensity I(θ max ) of the refracted light that is incident on at least one of the plurality of concave portions 140 from the organic light-emitting layer 116 and reaches the reflecting portion 130 after being refracted by at least one of the concave portions 140 will be described in detail.

[0174] Since the light refracted by the concave portion 140 is totally reflected from the flat portion 1131a, the intensity I(θ max ) of the refracted light reaching the reflecting portion 130 may be the same as the intensity of the light totally reflected from the flat portion 113a. In addition, the light refracted by the concave portion 140 may directly reach the reflecting portion 130 without being totally reflected from the flat portion 1131a.

[0175] Figure 7 is a schematic enlarged cross-sectional view of the portion C shown in Figure 3 , and Figure 8 is for showing Figure 7Schematic cross-sectional view of light refraction in one of the concave portions shown in the figure.

[0176] Now refer to Figure 7 and Figure 8 , in the display device 100 according to an embodiment of the present disclosure, the intensity I(θ max ) of the light refracted by at least one concave portion 140 is greater than the intensity I0 of the light incident on the concave portion 140, the light transmittance T P at a point in the concave portion 140, and the first angle θ max at which the light emitted from the organic light-emitting layer 116 is incident on any one of the plurality of recesses on the concave portion 140 from a direction perpendicular to the lower surface of the pixel electrode 114, the maximum angle Φ0 at which the light incident at the first angle is transmitted through the side surface of the concave portion 140 without being totally reflected back into the interior of the concave portion 140, and the second angle Φ formed between the upper surface of the concave portion 140 and the virtual line VL, the virtual line VL connecting the point on the concave portion 140 through which the light incident on the concave portion 140 is transmitted and the center C of the concave portion 140, which can be derived from a mathematical expression relating the first angle and the second angle Φ.

[0177] For example, the intensity I(θ max ) of the light refracted by at least one concave portion 140 is given by the following mathematical expression (or Equation 2).

[0178]

[0179] And, I(θ max ) can be set to satisfy this equation (or Equation 2).

[0180] Φ0 is the maximum angle at which the light incident at the first angle is transmitted through the side surface of the concave portion 140 without being totally reflected back into the interior of the concave portion 140, I0 is the intensity of the light incident on the concave portion 140, and T P is the light transmittance at the point CP on the concave portion 140, θ max is the first angle at which the light emitted from the organic light-emitting layer 116 is incident on one of the plurality of concave portions 140 from a direction perpendicular to the lower surface of the pixel electrode 114, and Φ is the second angle formed by the virtual line VL connecting the point CP through which the light incident on the concave portion 140 is transmitted and the center C of the concave portion 140 and the upper surface of the concave portion 140. Here, the side surface of the concave portion 140 may refer to the outer surface of the concave portion 140 provided in a direction other than perpendicular to the center C of the concave portion 140. In addition, refer to Figure 7 , the first angle θ maxIt may refer to the maximum angle at which the light emitted by the organic light-emitting layer 116 passes through the pixel electrode 114 and is incident on the second layer 1132 (or the recess 140).

[0181] Meanwhile, the light incident at the first angle θ max The maximum angle Φ0 at which the light incident at the first angle θ is transmitted through the side surface of the recess 140 without being totally reflected into the interior of the recess 140 is given by the following mathematical expression (or Equation 3), and can be set to satisfy the following mathematical expression (or Equation 3).

[0182] Φ0 = atan(-AR / tan(θ max - asin(N)))

[0183] And the maximum angle Φ0 can be set to satisfy this mathematical expression (or Equation 3).

[0184] AR is the aspect ratio of one recess 140 among the plurality of recesses, θ max is the first angle, and N is the ratio of the refractive index of the first layer 1131 to the refractive index of the second layer 1132. Here, the aspect ratio is the ratio of the length H in the vertical direction from the center C of the recess 140 to the periphery of the recess 140 to the radius R of the recess 140.

[0185] In the above Equation 2, the light transmittance T at the point CP of the recess 140 P is given by the following mathematical expression (or Equation 4),

[0186]

[0187] And the light transmittance T P can be set to satisfy this mathematical expression (or Equation 4).

[0188] θ1 is the incident angle of the light incident on one recess 140 among the plurality of recesses, θ2 is the refraction angle of the light transmitted through the recess 140, and N is the ratio of the refractive index of the first layer 1131 to the refractive index of the second layer 1132.

[0189] The incident angle θ1 of the light incident on the recess 140 can be the angle between the normal n of the tangent line at the point CP of the recess 140 through which the light incident on the recess 140 is transmitted to the recess 140 and the light incident on the recess 140.

[0190] According to an example, the incident angle θ1 is given by the following mathematical expression (or Equation 5).

[0191] θ1 = π / 2 - m - θ max

[0192] Moreover, the incident angle θ1 can be set to satisfy the mathematical expression (or Equation 5).

[0193] π is 3.14, m is the slope of the tangent line of the point CP through which the light of the concave portion 140 is incident into the concave portion 140, and θ max is the first angle.

[0194] The refraction angle θ2 of the light transmitted through the concave portion 140 can be the angle between the light transmitted through the concave portion 140 and the normal line n (or the slope of the normal line n).

[0195] According to an example, the refraction angle θ2 is given by the following equation (or Equation 6),

[0196] θ2 = asin(N sin(θ1))

[0197] Moreover, the refraction angle θ2 can be set to satisfy the mathematical expression (or Equation 6).

[0198] N is the ratio of the refractive index of the first layer 1131 to the refractive index of the second layer 1132, and θ1 is the incident angle of the light incident on the concave portion 140.

[0199] In the above Equation 5, the slope m of the tangent line of the point CP through which the light of the concave portion 140 is transmitted is equal to the following equation (or Equation 7):

[0200]

[0201] Moreover, the slope m can be set to satisfy the mathematical expression (or Equation 7).

[0202] AR is the aspect ratio of one concave portion 140 among the plurality of concave portions, and Φ is the second angle formed by the virtual line VL connecting the point CP through which the light incident on the concave portion 140 is transmitted and the center C of the concave portion 140 and the upper surface CUF of the concave portion 140. According to an example, the upper surface CUF of the concave portion 140 can refer to an imaginary plane (or imaginary line) provided in a plane equal to the radius R passing through the center C of the concave portion 140, as Figure 8 shown. For example, in Figure 8 the upper surface CUF of the concave portion 140 can be an imaginary plane (or imaginary line) passing through the center C of the concave portion 140 in the first direction (X-axis direction).

[0203] The display device 100 according to an embodiment of the present disclosure is provided with the first layer 1131, the second layer 1132, and the concave portion 140 that satisfy Equation 2 to Equation 7, so that the light incident on one of the plurality of concave portions 140 can be refracted to an adjacent concave portion 140 through the periphery of the concave portion 140, asFigure 7 As shown. However, and not necessarily limited thereto, the display device 100 according to an embodiment of the present disclosure may be provided with a first layer 1131, a second layer 1132, and a concave portion 140 that satisfy Equation 2 to Equation 7. Thus, the light incident on one concave portion 140 among the plurality of concave portions 140 may be directly refracted to the reflection portion 130 through the outer surface of the concave portion 140.

[0204] On the other hand, according to the above mathematical expressions (Equation 2 to Equation 7), the transmittance of the concave portion 140 may be determined according to the aspect ratio AR of the concave portion 140. Since the incident angle of light changes according to the aspect ratio AR of the concave portion 140, the display device 100 according to an embodiment of the present disclosure may change the light transmittance of the concave portion 140 according to the aspect ratio AR of the concave portion 140 to prevent the light from being totally reflected into the concave portion 140 and unable to be guided to the outside of the substrate 110. Therefore, the inventors of the display device 100 according to an embodiment of the present disclosure calculate the amount of light transmitted through the concave portion 140 according to the incident angle according to the aspect ratio AR of the concave portion 140, and derive the light efficiency (or light efficiency increase rate) for the aspect ratio of the concave portion 140.

[0205] Specifically, the inventors of the display device 100 of the present disclosure may know the intensity of the refracted light refracted by at least one concave portion 140 and reaching the reflection portion 130 (or the baseline ML) through the above Equation 2 to Equation 7. Therefore, the inventors change the aspect ratio AR of the concave portion 140 to derive a graph regarding the intensity of the refracted light.

[0206] Hereinafter, with reference to Figure 9 and Figure 10 , the light intensity as a function of the angle of the light incident on the concave portion 140, and the ratio of the refracted light intensity as a function of the aspect ratio of the concave portion 140 will be described in detail.

[0207] Figure 9 To show a graph of the light intensity as a function of the angle of the light incident on the concave portion of the display device according to an embodiment of the present disclosure, and Figure 10 To show a graph of the ratio of the refracted light intensity as a function of the aspect ratio of the concave portion of the display device according to an embodiment of the present disclosure.

[0208] With reference to Figure 9 , in the display device 100 according to an embodiment of the present disclosure, the first angle θ maxis the maximum angle at which light emitted by the organic light emitting layer 116 is incident on one of the concave portions 140 in the plurality of concave portions from a direction perpendicular to the lower surface of the pixel electrode 114. The angle at which light emitted by the organic light emitting layer 116 is incident on one of the concave portions 140 may vary, and the reason for setting it to the maximum angle is that, instead of reflecting light intensity at all angles, the reflected light intensity at the angle of the peak point seen in the light distribution of the device has a higher value than the light intensity at other angles.

[0209] Reference Figure 9 , in order to describe the light intensity as a function of the angle of light incident on the concave portion 140, the horizontal axis represents the angle of light incident on the concave portion 140, that is, θ, and the vertical axis represents the light intensity. Assuming that the angle of light incident on the concave portion 140 is the incident angle, as Figure 9 As shown in , when the incident angle is 0 degrees (°), the light intensity is 1. Figure 9 As shown in the graph in , the light intensity tends downward from 0 degrees to about 52 degrees, then tends upward from about 52 degrees to about 83 degrees, and then tends downward again from about 83 degrees and above. Therefore, it can be seen that at an incident angle of about 83 degrees, the light intensity is about 0.95. Figure 9 , the light intensity is described as having a maximum light intensity at about 83 degrees, but is not limited thereto, and the maximum light intensity may vary according to the light distribution of the emitting light element. Therefore, the inventors of the display device 100 according to the present specification have invented a method based on the first angle θ when incident on the concave portion 140. max The maximum light intensity is obtained at the maximum angle, and the above-mentioned equations 2 to 7 are derived.

[0210] Figure 10 140, and the vertical axis indicates the intensity (I(θ) of the refracted light incident on the reflective portion 130. max )) and the maximum intensity of the refracted light (I(θ max ) max ) ratio ((I(θ max ) / (I(θ max ) max For example, if the maximum intensity (I(θ max ) max ) is referred to as 100, and the intensity (I(θ max )) is called 10, and the ratio of the intensity of the refracted light may be 10%. The intensity (I(θ max )) and the maximum intensity of the refracted light (I(θmax ) max )'s ratio is shown on the vertical axis of Figure 10 as (I(θ max )) / I(θ max )) max ), but since it is a ratio, it can be I(θ max )) / I(θ max )) max multiplied by the value of 100.

[0211] Referring again to Figure 10 , the topmost first line Ln1 is a line indicating the ratio of the intensity of the refracted light according to the aspect ratio AR of the concave portion 140 when the first angle θ max is 70 degrees. The second line Ln2 immediately below the first line Ln1 is a line indicating the ratio of the intensity of the refracted light according to the aspect ratio AR of the concave portion 140 when the first angle θ max is 75 degrees. The third line Ln3 immediately below the second line Ln2 is a line indicating the ratio of the intensity of the refracted light according to the aspect ratio AR of the concave portion 140 when the first angle θ max is 80 degrees. The fourth line Ln4 immediately below the third line Ln3 is a line indicating the ratio of the intensity of the refracted light according to the aspect ratio AR of the concave portion 140 when the first angle θ max is 85 degrees.

[0212] As Figure 10 shown, it can be seen that when the aspect ratio AR of the concave portion 140 is greater than or equal to 1.0, all of the first line Ln1 to the fourth line Ln4 have a ratio of the intensity of the refracted light greater than or equal to 90% (I(θ max )) / I(θ max )) max ). That is to say, as the aspect ratio AR of the concave portion 140 increases, the intensity of the refracted light tends to converge to a certain maximum value. Therefore, the display device 100 according to an embodiment of the present disclosure can be set such that the aspect ratio AR of each of the plurality of concave portions 140 is 1 or greater, so that the intensity I(θ max ) of the refracted light reaching the reflection portion 130 relative to the maximum intensity of the refracted light (I(θ max )) max ) can be greater than or equal to 90%, thereby maximizing the light extraction efficiency through the reflection portion 130.

[0213] Therefore, the display device 100 according to an embodiment of the present disclosure is configured to have a plurality of concave portions 140 (e.g., an aspect ratio (AR) greater than or equal to 1) and the shapes of the first layer 1131 and the second layer 1132 (e.g., the ratio of the refractive indices of the first layer 1131 and the second layer 1132) that satisfy the above equations 2 to 7. Since, among the light incident on the concave portion 140, the light having an intensity of the refracted light (I(θ max ) max ) greater than or equal to 90% of the maximum intensity of the refracted light (I(θ max )) can be refracted toward the reflection portion 130, the light extraction efficiency (or front light extraction efficiency) can be improved.

[0214] In addition, the display device 100 according to an embodiment of the present disclosure is configured to have the shortest horizontal distance (PHL) between the reflection portion 130 (or the lower surface 130b of the reflection portion 130) that satisfies the above equation 1 and the end of the upper surface 1131a of the first layer 1131. The light refracted by at least one concave portion 140 can be configured to be reflected by the reflection portion 130 after being totally reflected from the upper surface 1131a of the first layer 1131 (or the boundary between the first layer 1131 and the second layer 1132). Therefore, due to the flat surface 1131a of the display device 100 according to an embodiment of the present disclosure provided at the shortest horizontal distance (PHL) between the reflection portion 130 and the end of the upper surface 1131a of the first layer 1131 (or the lower surface 130b of the reflection portion 130), the light extraction efficiency (or front light extraction efficiency) can be maximized.

[0215] The display device of the present disclosure may have a plurality of concave portions spaced farther from the edge of the pixel electrode than the reflection portion provided in the non-light-emitting region, so that the light extraction efficiency in the non-light-emitting region can be improved by refraction of light through at least one concave portion.

[0216] In addition, since the display device of the present disclosure can extract light even in the non-light-emitting region, compared with a display device without a reflection portion, it can have the same luminous efficiency or even better luminous efficiency at a lower power, thereby reducing the overall power consumption.

[0217] In addition, the display device of the present disclosure may make the aspect ratio of each of the plurality of concave portions included in each of the plurality of sub-pixels greater than 1, thereby maximizing the light extraction efficiency of the light emitted from the light-emitting element layer.

[0218] The effects obtained from the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will become apparent to those of ordinary skill in the art from the description.

[0219] Embodiments of the present disclosure have been described in more detail with reference to the accompanying drawings. However, the present disclosure is not necessarily limited to these embodiments and can be practiced with various modifications without departing from the technical concept of the present disclosure. Therefore, the embodiments disclosed herein are intended to illustrate rather than limit the technical concept of the present disclosure, and the scope of the technical concept of the present disclosure is not limited by these embodiments. Therefore, the above embodiments are exemplary in all aspects and should be understood as non-limiting. All technical concepts within the scope of protection of this specification should be construed as being included within the scope of the claims of this specification.

Claims

1. A display device, comprising: a substrate including a plurality of pixels having a plurality of sub-pixels, wherein the substrate includes a light emitting region and a non-light emitting region adjacent to the light emitting region; a pattern portion, which is arranged to be recessed into the non-light-emitting region between the plurality of sub-pixels on the substrate; as well as A reflecting portion is arranged to be inclined on the pattern portion, Wherein, each of the plurality of sub-pixels comprises: a plurality of concave portions disposed in the light emitting region; and A pixel electrode is disposed on the plurality of concave portions, and Wherein, the spacing distance between the multiple concave portions and the reflective portion is greater than the spacing distance between the pixel electrode and the reflective portion.

2. The display device according to claim 1, wherein: An outermost concave portion among the plurality of concave portions is spaced apart from an edge of the pixel electrode.

3. The display device according to claim 1, wherein: The plurality of sub-pixels are disposed on the substrate and include a coating layer, the coating layer including a first layer and a second layer on the first layer, the first layer including the plurality of concave portions, The first layer includes a flat surface disposed parallel to the substrate, and The flat surface is disposed closer to the substrate than the plurality of concave portions.

4. The display device according to claim 1, wherein: The pattern part is spaced apart from the light emitting area.

5. The display device according to claim 1, wherein: The width of the pattern portion decreases in a direction from the reflection portion toward the substrate.

6. The display device according to claim 3, wherein: The first layer includes an inclined surface connecting the flat surface and the plurality of concave portions, The flat surface of the first layer and the inclined surface of the first layer are connected at a first point, and The first point is arranged to overlap with the pixel electrode.

7. The display device according to claim 6, wherein: The plurality of sub-pixels include: an organic light emitting layer in the light emitting region and the non-light emitting region; and a reflective electrode on the organic light emitting layer, and The reflecting portion is a part of the reflecting electrode.

8. The display device according to claim 7, wherein: The reflective portion includes a lower surface in contact with the organic light emitting layer, The lower surface of the reflecting portion includes a second point disposed uppermost on the pattern portion, and The second point is an inflection point where the reflective electrode is bent in the pattern portion.

9. The display device according to claim 8, wherein: The upper surface of the reflecting portion includes a third point disposed at the lowermost side on the pattern portion, The non-luminous region includes: a first region between the edge of the pixel electrode and the second point, and a second region between the second point and the third point, wherein the second region is adjacent to the first region, and The reflecting portion is disposed in the second region.

10. The display device according to claim 9, wherein: The horizontal distance PHL between the second point and the first point is set to satisfy the following mathematical expression, PHL=h*tan(2a), Herein, h is the thickness of the second layer disposed on the flat surface of the first layer, and a is the angle between the reflective portion and the flat surface of the first layer.

11. The display device according to claim 10, wherein: The plurality of concave portions are spaced apart from the reflecting portion by a distance greater than the horizontal distance.

12. The display device according to claim 10, further comprising: a data line supplying a data signal to each of the plurality of sub-pixels, Wherein, the data line is arranged to overlap with the first area.

13. The display device according to claim 1, wherein: The plurality of sub-pixels include organic light-emitting layers in the light-emitting region and the non-light-emitting region, The intensity I(θ) of the refracted light after the light emitted from the organic light emitting layer is incident on any one of the plurality of concave portions at a first angle from a direction perpendicular to the lower surface of the pixel electrode and is refracted by the at least one concave portion and reaches the reflective portion is max ) is set to satisfy the following mathematical expression, Wherein, Φ0 is the maximum angle at which light incident at the first angle is transmitted to the side surface of the concave portion without being totally reflected to the inside of the concave portion, I0 is the intensity of the light incident on the concave portion, and T P is the light transmittance at a point on the concave portion, θ max is the first angle, and Φ is a second angle between a virtual line VL connecting the center of the concave portion and a point of the concave portion through which light incident on the concave portion is transmitted, and the upper surface of the concave portion.

14. The display device according to claim 13, wherein: The plurality of sub-pixels are disposed on the substrate and include the coating layer, the coating layer including: a first layer including the plurality of concave portions and a second layer on the first layer, The maximum angle Φ0 is set to satisfy the following mathematical expression, Φ0=tan(-AR / tan(θ max -salt(N))) Wherein, AR is the aspect ratio of one of the plurality of concave portions, θ max is the first angle, and N is the ratio of the refractive index of the first layer to the refractive index of the second layer.

15. The display device according to claim 13, wherein: The light transmittance T of the point of the concave portion P is set to satisfy the following mathematical expression, Herein, θ1 is the incident angle of light incident on the concave portion, θ2 is the refraction angle of light transmitted through the concave portion, and N is the ratio of the refractive index of the first layer to the refractive index of the second layer.

16. The display device according to claim 15, wherein: The incident angle θ1 is the angle between the normal line of the tangent line of the point of the concave portion and the light incident on the concave portion, The incident angle θ1 is set to satisfy the following mathematical expression, θ1=π / 2-m-θ max Here, π is a constant, and m is the slope of the tangent line at the point of the concave portion.

17. The display device according to claim 16, wherein: The refraction angle θ2 is the angle between the light transmitted through the concave portion and the normal line. The refraction angle θ2 is set to satisfy the following mathematical expression, θ2=asin(N sin(θ1)).

18. The display device according to claim 16, wherein: The slope m is set to satisfy the following mathematical expression, Herein, AR is the aspect ratio of a concave portion among the plurality of concave portions.

19. The display device according to claim 14, wherein: The first angle is a maximum angle at which light emitted by the organic light emitting layer passes through the pixel electrode to be incident on the second layer.

20. The display device according to claim 14, wherein: When the aspect ratio of the concave portion is greater than or equal to 1.0, the intensity of the refracted light is greater than or equal to 90% of the maximum intensity of the refracted light.

21. The display device according to claim 1, further comprising: a data line supplying a data signal to each of the plurality of sub-pixels, wherein the data line is arranged to extend between the plurality of sub-pixels arranged along the first direction in a second direction intersecting the first direction, and The pattern part partially overlaps the data line in the first direction and the second direction.

22. The display device according to claim 1, wherein: The plurality of sub-pixels include a first sub-pixel, a second sub-pixel, a third sub-pixel, and a fourth sub-pixel sequentially arranged along a first direction, The substrate includes a reference line extending between the second sub-pixel and the third sub-pixel along a second direction intersecting the first direction, and At least a portion of the reference line overlaps the pattern portion.

23. The display device according to claim 1, wherein: The pattern part is disposed along the shape of the pixel electrode.

24. The display device according to claim 1, further comprising: a thin film transistor for driving each of the plurality of sub-pixels, Wherein, the substrate includes a connection area connecting the thin film transistor and the pixel electrode, and The pattern portion is not provided in the connection region.

25. The display device according to claim 1, further comprising a data line for supplying a data signal to each of the plurality of sub-pixels, in, The data line is arranged to extend along a second direction intersecting the first direction between the plurality of sub-pixels arranged along the first direction, The pattern portion includes a first pattern line extending along the first direction and a second pattern line extending along the second direction, and The second pattern lines do not overlap the data lines in the second direction. 26 . The display device according to claim 25 , wherein the first pattern line is disposed between sub-pixels for emitting light of the same color, and the second pattern line is disposed between sub-pixels for emitting light of different colors.

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