Light-emitting display device and pixel structure

Abstract

The invention relates to a light emitting display device and a pixel structure. A light emitting display device according to the present disclosure includes: a substrate; a driving element layer provided on the substrate; a reflective electrode provided on the driving element layer; a partition wall covering a periphery of the reflective electrode and exposing a middle portion of the reflective electrode; a planarization layer filled in an inner region surrounded by the partition wall and including a first refractive layer and a second refractive layer; an anode disposed on the planarization layer; a light emitting layer disposed on the anode; a cathode provided on the light emitting layer; and an encapsulation layer disposed on the cathode.

Description

Technical Field

[0001] The present disclosure relates to a display device and a pixel structure, and more particularly, for example but not limited to, to a light-emitting display device and a pixel structure with improved light-emitting efficiency. Background Art

[0002] Recently, a head-mounted display (HMD) including an organic light-emitting diode display has been developed. The HMD is a wearable monitoring device, for example, for virtual reality (VR) or augmented reality (AR), which is worn, for example, in the form of glasses or a helmet to focus on a distance near the user's eyes. Such a head-mounted display may be equipped with a small organic light-emitting diode display having high-resolution characteristics. The head-mounted display may provide a virtual reality image to the user. Alternatively, the head-mounted display may include a liquid crystal display device, an inorganic light-emitting display device, or the like.

[0003] The descriptions provided in the Background section should not be considered prior art merely because they are mentioned in or related to the Background section.The Background section may include information describing one or more aspects of the subject technology. Summary of the invention

[0004] In particular, in ultra-high-density resolution display devices with a pixel density (pixels per inch (ppi)) of 4K or above, since the size of the pixels is very small, structural improvements are required to improve light efficiency in order to provide brighter and clearer image quality with the same power consumption.

[0005] In order to solve the above-mentioned problems, an object of the present disclosure is to provide a top emission type light emitting display device or a top emission type transparent light emitting display device having high brightness compared with power consumption.

[0006] Some embodiments of the present disclosure may be directed to include a color filter having a structure capable of improving light efficiency, thereby providing a top-emission type light-emitting display device or a top-emission type transparent light-emitting display device capable of low-power driving with higher brightness at the same power consumption.

[0007] To achieve one or more purposes of the present disclosure, a light-emitting display device according to one or more exemplary embodiments of the present disclosure may include: a substrate; a driving element layer disposed on the substrate; a reflective electrode disposed on the driving element layer; a partition wall covering the periphery of the reflective electrode and exposing a middle portion of the reflective electrode; a planarization layer filled in an inner area surrounded by the partition wall and including a first refractive layer and a second refractive layer; an anode disposed on the planarization layer; a light-emitting layer disposed on the anode; a cathode disposed on the light-emitting layer; and an encapsulation layer disposed on the cathode.

[0008] In an exemplary embodiment, an interface between the first refractive layer and the second refractive layer has a curved surface.

[0009] In an exemplary embodiment, the first refractive layer has a first refractive index. The second refractive layer has a second refractive index different from the first refractive index.

[0010] In an exemplary embodiment, the first refractive index is less than the second refractive index.

[0011] In an exemplary embodiment, a cross-sectional shape of the first refractive layer has a convex lens shape. A cross-sectional shape of the second refractive layer has a concave lens shape.

[0012] In an exemplary embodiment, an upper surface of the planarization layer is disposed at the same height as an upper surface of the partition wall.

[0013] In an exemplary embodiment, the planarization layer includes a plurality of silicon dioxide nanoparticles.

[0014] In an exemplary embodiment, the planarization layer includes a plurality of quantum dots for realizing a specific color.

[0015] In an exemplary embodiment, the light emitting display device further includes a color filter layer disposed on the encapsulation layer.

[0016] In an exemplary embodiment, the planarization layer includes a plurality of quantum dots realizing colors corresponding to the color filter layer.

[0017] In addition, a light-emitting display device according to one or more exemplary embodiments of the present disclosure includes: a substrate including red pixels, green pixels, and blue pixels; a driving element layer disposed on the substrate; a reflective electrode disposed on each of the red pixels, green pixels, and blue pixels on the driving element layer; a partition wall covering the periphery of the reflective electrode and exposing a middle portion of the reflective electrode; a planarization layer located in an area surrounded by the partition wall and including a first refractive layer, a second refractive layer, and a third refractive layer; an anode disposed on each of the red pixels, green pixels, and blue pixels on the planarization layer; a dam covering the periphery of the anode and exposing a middle portion of the anode; a light-emitting layer disposed on the anode and the dam; and a cathode disposed on the light-emitting layer.

[0018] In an exemplary embodiment, the cross-sectional shape of the first refractive layer has a convex lens shape with a convex middle portion upward. The cross-sectional shape of the second refractive layer has a concave lens shape with a concave middle portion upward. The cross-sectional shape of the third refractive layer has a convex lens shape with a convex middle portion downward.

[0019] In an exemplary embodiment, the first refractive layer, the second refractive layer, and the third refractive layer have different refractive indices from each other.

[0020] In an exemplary embodiment, the first refractive layer has a first refractive index smaller than that of the second refractive layer. The second refractive layer has a second refractive index smaller than that of the third refractive layer. The third refractive layer has a third refractive index smaller than that of the anode.

[0021] In an exemplary embodiment, the light emitting display device further includes: an encapsulation layer disposed on the cathode; and a color filter layer including a red color filter at a red pixel, a green color filter at a green pixel, and a blue color filter at a blue pixel located on the encapsulation layer.

[0022] In an exemplary embodiment, the planarization layer includes a plurality of silicon dioxide nanoparticles.

[0023] In an exemplary embodiment, the planarization layer includes a plurality of first quantum dots at red pixels, a plurality of second quantum dots at green pixels, and a plurality of third quantum dots at blue pixels.

[0024] In an exemplary embodiment, the planarization layer includes a red pigment at the red pixel, a green pigment at the green pixel, and a blue pigment at the blue pixel.

[0025] The light-emitting display device according to one or more exemplary embodiments of the present disclosure includes a multi-layer refractive layer in the light-emitting region, so that the light extraction efficiency can be enhanced or maximized. Even in an ultra-high density resolution display device in which the size of the light-emitting region is very small, a higher brightness can be provided with the same power consumption. Therefore, low-power driving can be achieved.

[0026] The light-emitting display device according to one or more exemplary embodiments of the present disclosure has a structural feature of having a plurality of refractive layers having different refractive indices between an anode and a reflective electrode. As a result, light reflectivity can be enhanced and light extraction efficiency can be improved.

[0027] The light-emitting display device according to one or more exemplary embodiments of the present disclosure has a structure in which the interface between multiple refractive layers with different refractive indices has a curved shape. The total reflectivity at the interface can be significantly reduced. Therefore, by reducing or minimizing the amount of light captured inside the refractive layer by total reflection between the multiple refractive layers, the light extraction efficiency can be further improved.

[0028] In addition to the effects of the present disclosure mentioned above, other features and advantages of the present disclosure are described below or may be clearly understood by those skilled in the art from these descriptions and explanations.

[0029] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the inventive concepts as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The included drawings are used to provide a further understanding of the present disclosure and are incorporated into and constitute a part of this application. The drawings illustrate embodiments of the present disclosure and together with the description are used to explain the principles of the present disclosure. In the drawings:

[0031] Figure 1 is a plan view showing a schematic structure of a light emitting display device according to an exemplary embodiment of the present disclosure.

[0032] Figure 2 is a circuit diagram illustrating a structure of one pixel provided in a light emitting display device according to an exemplary embodiment of the present disclosure.

[0033] Figure 3 is an enlarged plan view showing a structure of three pixels sequentially disposed in a light emitting display device according to an exemplary embodiment of the present disclosure.

[0034] Figure 4 is along Figure 3 1 is a cross-sectional view taken along line II′ of FIG. 1 for illustrating a structure of one pixel in the light emitting display device according to the first exemplary embodiment of the present disclosure.

[0035] Figure 5A is a schematic diagram showing a light path in the case where a single transparent layer is provided between the anode and the reflective electrode.

[0036] Figure 5B Schematic diagram showing an optical path in the case where two layers having different refractive indexes are provided between the anode and the reflective electrode.

[0037] Figure 6 is along Figure 3 1 is an enlarged cross-sectional view taken along line II-II′ of FIG. 1 , for illustrating a structure of three pixels sequentially arranged in a light emitting display device according to a second exemplary embodiment of the present disclosure.

[0038] Figure 7 is along Figure 3 1 is an enlarged cross-sectional view taken along line II-II′ of FIG. 1 , for illustrating a structure of three pixels sequentially arranged in a light emitting display device according to a third exemplary embodiment of the present disclosure.

[0039] Figure 8 is along Figure 3 1 is an enlarged cross-sectional view taken along line II-II′ of FIG. 1 , for illustrating a structure of three pixels sequentially arranged in a light emitting display device according to a fourth exemplary embodiment of the present disclosure.

[0040] Fig. 9 is along Figure 31 is an enlarged cross-sectional view taken along line II-II′ of FIG. 1 , for illustrating a structure of three pixels sequentially arranged in a light emitting display device according to a fifth exemplary embodiment of the present disclosure.

[0041] Fig.10 is along Figure 3 1 is an enlarged cross-sectional view taken along line II-II′ of FIG. 1 for illustrating a structure of three pixels sequentially arranged in a light emitting display device according to a sixth exemplary embodiment of the present disclosure.

[0042] Throughout the drawings and detailed description, unless otherwise described, the same drawing reference numerals should be understood to refer to the same elements, features, and structures. The relative sizes and descriptions of these elements may be exaggerated for clarity, illustration, and convenience. DETAILED DESCRIPTION

[0043] The advantages and features of the present disclosure and their implementation methods will be explained by referring to the following embodiments described in the accompanying drawings. However, the present disclosure can be implemented in different forms and should not be construed as being limited to the embodiments described herein. On the contrary, these exemplary embodiments are provided to make the present disclosure sufficiently thorough and complete to help those skilled in the art fully understand the scope of the present disclosure. In addition, the scope of protection of the present disclosure is defined by the claims and their equivalents.

[0044] The shapes, sizes, ratios, angles, quantities, etc. shown in the accompanying drawings for describing various exemplary embodiments of the present disclosure are given only as examples. Therefore, the present disclosure is not limited to the details shown. Unless otherwise specified, the same reference numerals represent the same elements throughout the specification. In the following description, the detailed description of the relevant known functions or configurations may be omitted in the case where the detailed description of such known functions or configurations may unnecessarily obscure the main points of the present disclosure.

[0045] Reference will now be made in detail to exemplary embodiments of the present disclosure, examples of which are shown in the accompanying drawings. In all drawings, the same reference numerals are used to represent the same or similar parts as much as possible. In the specification, it should be noted that the same reference numerals that have been used to represent the same elements in other drawings are used to represent these elements as much as possible. In the following description, when the functions and configurations known to those skilled in the art are not related to the basic configuration of the present disclosure, their detailed description will be omitted. The terms described in the specification should be understood as follows.

[0046] The word "exemplary" is used to mean used as an example or illustration. An embodiment is an exemplary embodiment. Aspects are exemplary aspects. "An embodiment," "an example," "an aspect," etc. should not be construed as being superior or stronger than other implementations. Unless otherwise specified, an embodiment, an example, an exemplary embodiment, an aspect, etc. may refer to one or more embodiments, one or more examples, one or more exemplary embodiments, one or more aspects, etc. In addition, the term "may" encompasses all meanings of the term "can."

[0047] In the present specification, when the terms "including", "having", "comprising", etc. are used, one or more other elements may be added unless a term such as "only" is used. Unless the context clearly indicates otherwise, an element described in the singular is intended to include plural elements and vice versa.

[0048] When interpreting an element, the element is interpreted as including an error or tolerance range even if no explicit description of such error or tolerance range is provided.Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0049] In the description of various embodiments of the present disclosure, in the case of describing a positional relationship, for example, in the case of using "on", "above", "below", "above", "below", "next to", "near", etc. to describe the positional relationship between two components, unless more restrictive terms such as "close to", "directly", or "close to" are used, one or more other components may be located between the two components. For example, in the case where one element or layer is arranged "on" another element or layer, a third layer or element may be inserted therebetween. In addition, if a first element is described as being "on" a second element, it does not necessarily mean that the first element is located above the second element in the figure. The upper and lower parts of the related objects may change according to the orientation of the object. Therefore, in the case where a first element is described as being "on" a second element, depending on the orientation of the object, the first element may be located "below" the second element or "above" the second element in the figure or in the actual configuration.

[0050] Terms such as "below", "lower", "above", "upper", etc. may be used herein to describe the relationship between elements shown in the drawings. It should be understood that these terms are spatially relative and based on the orientation shown in the drawings.

[0051] When describing a temporal relationship, when the temporal order is described as, for example, "after", "subsequently", "next", or "before", discontinuities may be included unless more restrictive terms such as "just", "immediately", or "directly" are used.

[0052] It should 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 because these terms are not used to define a specific order. These terms are only used to distinguish one element from another element. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the present disclosure.

[0053] When describing various elements in the present disclosure, terms such as first, second, A, B, (a) and (b) may be used. These terms are only used to distinguish one element from another element, rather than to define the specific properties, order, sequence or quantity of the elements. Where an element is described as being "linked", "connected" or "connected" to another element, the element may be directly or indirectly connected to the other element unless otherwise stated. It should be understood that one or more additional elements may be "interposed" between two elements described as being "linked", "connected" or "connected" to each other.

[0054] It should be understood that the term "at least one" should be understood to include any and all combinations of one or more of the related listed items. For example, the meaning of "at least one of a first element, a second element, and a third element" includes the combination of all three listed elements, the combination of any two of the three elements, and each individual element (i.e., the first element, the second element, and the third element).

[0055] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which the exemplary embodiments belong. It should also be understood that terms (e.g., terms defined in commonly used dictionaries) should be interpreted as having, for example, a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined as such herein. For example, as will be understood by a person of ordinary skill in the art, the term "component" or "unit" may be applied to, for example, a separate circuit or structure, an integrated circuit, a computing block of a circuit device, or any structure configured to perform the described function.

[0056] As those skilled in the art can fully understand, the features of the various embodiments of the present disclosure can be partially or completely connected or combined with each other, and can interoperate with each other in various ways and drive technology. The embodiments of the present disclosure can be implemented independently of each other, or can be implemented together in a mutually dependent relationship.

[0057] Hereinafter, an example of a display device according to the present disclosure will be described in detail with reference to the accompanying drawings. Throughout the drawings, the same reference numerals are used as much as possible to refer to the same or similar components.

[0058] Hereinafter, the present disclosure will be described with reference to the accompanying drawings. Since the scale of each element shown in the drawings may be different from the actual scale for the convenience of description, the present disclosure is not limited to the scale shown in the drawings.

[0059] Figure 1 is a plan view showing a schematic structure of a light emitting display device according to an exemplary embodiment of the present disclosure. Figure 1 In FIG. 1 , the X-axis refers to a direction parallel to the scan lines, the Y-axis refers to a direction parallel to the data lines, and the Z-axis refers to a height direction of the display device.

[0060] Reference Figure 1 , the electroluminescent display includes a substrate 110, a gate (or scan) driver 200, a pad part 300, a source driver integrated circuit (IC) 410, a flexible circuit film 430, a circuit board 450, and a timing controller 500. However, embodiments of the present disclosure are not limited thereto.

[0061] As an example, the substrate 110 may include an electrically insulating material, a rigid material, or a flexible material, but is not limited thereto. The substrate 110 may be made of glass, metal, or plastic, but is not limited thereto. When the light-emitting display device is a flexible display, the substrate 110 may be made of a flexible material such as plastic. For example, the substrate 110 may include a transparent polyimide material. The embodiment is not limited thereto. As an example, the substrate 110 may include a translucent material or an opaque material.

[0062] The substrate 110 may include a display area AA and a non-display area NDA. The display area AA, which is an area for presenting a video image, may be defined as a majority of the middle area of ​​the substrate 110, but is not limited thereto. In the display area AA, a plurality of pixels P are arranged in a matrix. In addition, a plurality of scan lines SL (or gate lines) and a plurality of data lines DL may be arranged to intersect each other. Each pixel P may be arranged at the intersection of a scan line SL extending to the X-axis and a data line DL extending to the Y-axis.

[0063] Here, the pixel P can represent any color of red, green and blue or red, green, blue or white, but is not limited to this. Other colors such as cyan, magenta, yellow, etc. can also be represented. Red pixels, green pixels and blue pixels can be gathered, or red pixels, green pixels, blue pixels and white pixels can be gathered to form a unit pixel, but is not limited to this. For example, each pixel P representing each color can be called a "sub-pixel", and it can be interpreted that these "sub-pixels" form a "pixel". As another example, it can be interpreted that the pixel P representing each color is called a "pixel", and three or four of these "pixels" are gathered to form a "unit pixel". Hereinafter, the latter case will be described.

[0064] The non-display area NDA, which is an area where a video image is not presented, may be defined in an adjacent area or a peripheral area of ​​the substrate 110 surrounding all or part of the display area AA. In the non-display area NDA, the gate driver 200 and / or the pad portion 300 may be formed or disposed. The embodiment is not limited thereto. As an example, at least one of the gate driver 200 and the pad portion 300 may not be formed or disposed in the non-display area NDA.

[0065] According to the gate control signal received from the timing controller 500 through the pad portion 300, the gate driver 200 can provide a scan (or gate) signal to the scan line SL. The gate driver 200 can be formed at the non-display area NDA on any one side or multiple sides of the display area DA on the substrate 110 in a gate driver in panel (GIP) type. The GIP type means that the gate driver 200 is directly formed on the substrate 110. For example, the gate driver 200 can be configured with a shift register. In the GIP type, the transistors of the shift register for the gate driver 200 are directly formed on the upper surface of the substrate 110. The embodiment is not limited to this. As an example, the gate driver 200 can be set separately (for example, set on a separate panel), and then connected to the substrate 110 (for example, the pad portion 300) by a tape automated bonding (TAB) method, a chip on glass (COG) method, a chip on panel (COP) method, or a chip on film (COF) method, but is not limited to this.

[0066] The pad portion 300 may be disposed in the non-display area NDA on one or more sides of the display area AA of the substrate 110. The pad portion 300 may include a data pad connected to each data line DL, a driving current pad connected to the driving current line VDD, a high potential pad receiving a high potential voltage, and / or a low potential pad receiving a low potential voltage. One or more additional pads may also be included.

[0067] The source driver IC 410 may receive digital video data and a source control signal from the timing controller 500. The source driver IC 410 may convert the digital video data into an analog data voltage according to the source control signal and then provide it to the data line. When the source driver IC 410 is manufactured as a chip type, it may be mounted on the flexible circuit film 430 in a chip on film (COF) or chip on plastic (COP) type, but is not limited thereto.

[0068] The flexible circuit film 430 may include a plurality of first link lines connecting the pad portion 300 to the source driver IC 410, a plurality of second link lines connecting the pad portion 300 to the circuit board 450, and / or a plurality of third link lines connecting the source driver IC 410 to the circuit board 450, but is not limited thereto. The flexible circuit film 430 may be attached to the pad portion 300 using an anisotropic conductive film so that the pad portion 300 may be connected to the first link lines or the second link lines of the flexible circuit film 430, but is not limited thereto.

[0069] The circuit board 450 may be attached to the flexible circuit film 430. The circuit board 450 may include a plurality of circuits implemented as a driving chip. For example, the circuit board 450 may be a printed circuit board or a flexible printed circuit board.

[0070] The timing controller 500 may receive digital video data and a timing signal from an external system board through a cable of the circuit board 450. The timing controller 500 may generate a gate control signal for controlling the operation timing of the gate driver 200 and a source control signal for controlling the source driver IC 410 based on the timing signal. The timing controller 500 may provide the gate control signal to the gate driver 200, and provide the source control signal to the source driver IC 410. Depending on the product type, the timing controller 500 may be integrated into one driver chip with the source driver IC 410, and / or may be mounted on the substrate 110 to be connected to the pad portion 300.

[0071] In the following, reference is made to Figures 2 to 3 , a detailed structure of a light emitting display device according to an exemplary embodiment of the present disclosure will be described. Figure 2 is a circuit diagram illustrating a structure of one pixel provided in a light emitting display device according to an exemplary embodiment of the present disclosure. Figure 3 is an enlarged plan view showing a structure of three pixels sequentially disposed in a light emitting display device according to an exemplary embodiment of the present disclosure.

[0072] Reference Figures 2 to 3, each pixel P of the light-emitting display according to the present disclosure may be defined by a scan line SL, a data line DL, and a drive current line VDD. Each pixel P of the light-emitting display may include a switch thin film transistor ST, a drive thin film transistor DT, a light-emitting diode OLE, and a storage capacitor Cst. A high-level voltage for driving the light-emitting diode OLE may be provided to the drive current line VDD. The embodiment is not limited thereto. At least one of the above components may be omitted, and / or one or more additional components may also be included. As an example, more thin film transistors, storage capacitors, and signal lines may be included in each pixel.

[0073] A switching thin film transistor ST and a driving thin film transistor DT may be formed on the substrate 110. For example, the switching thin film transistor ST may be configured to be connected to the intersecting scan line SL and data line DL. The switching thin film transistor ST may include a gate SG, a semiconductor layer SA, a source SS, and a drain SD. The gate SG may be a portion of the scan line SL. The semiconductor layer SA may be arranged to intersect the gate SG. The overlapping portion of the semiconductor layer SA and the gate SG may be defined as a channel region. The source SS may be branched from or connected to the data line DL, and the drain SD may be connected to the driving thin film transistor DT. The source SS may be one side of the semiconductor layer SA relative to the channel region, and the drain SD may be the other side of the semiconductor layer SA. By providing a data signal to the driving thin film transistor DT, the switching thin film transistor ST may play a role in selecting a pixel P to be driven and controlling the timing of applying the data signal to the storage capacitor Cst.

[0074] The driving thin film transistor DT may play the following role: driving the light emitting diode OLE of the selected pixel P through the switching thin film transistor ST, and controlling the current flowing through the light emitting diode OLE according to the voltage applied to the gate SG to control the brightness of the light emitting diode OLE. The driving thin film transistor DT may include a gate DG, a semiconductor layer DA, a source DS, and a drain DD. The gate DG of the driving thin film transistor DT may be connected to the drain SD of the switching thin film transistor ST. For example, the gate DG of the driving thin film transistor DT may extend from the drain SD of the switching thin film transistor ST. In the driving thin film transistor DT, the drain DD may be branched from the driving current line VDD or connected to the driving current line. In addition, the source DS may be connected to the anode (or pixel electrode) ANO of the light emitting diode (or light emitting element) OLE. The semiconductor layer DA may be arranged to cross the gate DG. In the semiconductor layer DA, the portion overlapping with the gate DG may be defined as a channel region. The source DS may be connected to one side of the semiconductor layer DA relative to the channel region, and the drain DD may be connected to the other side of the semiconductor layer DA. The storage capacitor Cst may be disposed between the gate electrode DG of the driving thin film transistor DT and the anode electrode ANO of the light emitting diode OLE.

[0075] The light emitting diode OLE may generate light according to the current controlled by the driving thin film transistor DT. The driving thin film transistor DT may control the amount of current flowing from the driving current line VDD to the light emitting diode OLE according to the voltage difference between the gate DG and the source DS.

[0076] The light emitting diode OLE may include an anode ANO, a light emitting layer EL, and a cathode CAT. The light emitting diode OLE may emit light according to a current controlled by the driving thin film transistor DT. In other words, the light emitting diode OLE may provide an image by emitting light according to a current controlled by the driving thin film transistor DT. The anode ANO of the light emitting diode OLE may be connected to the source DS of the driving thin film transistor DT. The cathode CAT (or common electrode) may be a part of a low power line VSS provided with a low potential voltage, or may be branched from or connected to the low power line VSS. Therefore, the light emitting diode OLE may be driven by a current flowing from the driving current line VDD to the low power line VSS controlled by the driving thin film transistor DT.

[0077] A plurality of pixels P may be arranged on the substrate 110. For example, a red pixel P_R, a green pixel P_G, and a blue pixel P_B may be arranged and disposed in sequence in the horizontal direction. A combination of a red pixel P_R, a green pixel P_G, and a blue pixel P_B may constitute a pixel. In another case, a red pixel, a green pixel, a white pixel, and a blue pixel may be arranged in sequence in the horizontal direction, the vertical direction, or any direction between the horizontal direction and the vertical direction. A red pixel, a green pixel, a white pixel, and a blue pixel may form a unit pixel. Embodiments are not limited thereto. Pixels of other colors may be included alternatively or additionally. Figure 3 It is shown that three pixels P are arranged in sequence along the horizontal direction.

[0078] <First Exemplary Embodiment>

[0079] Further references Figure 4 , a cross-sectional structure of a light emitting display device according to a first exemplary embodiment of the present disclosure will be described. Figure 4 is along Figure 3 1 is a cross-sectional view taken along line II′ of FIG. 1 for illustrating a structure of one pixel in the light emitting display device according to the first exemplary embodiment of the present disclosure.

[0080] Reference Figure 3 and Figure 4The light-emitting display device according to the first exemplary embodiment of the present disclosure may include a substrate 110, a driving element layer 220, a light-emitting element layer 330, an encapsulation layer 440, and a color filter layer CF, but is not limited thereto. The driving element layer 220 may include a plurality of thin layers formed on the substrate 110. The driving element layer 220 may include a switching thin film transistor ST and a driving thin film transistor DT.

[0081] On the substrate 110, a data line DL, a driving current line VDD, and a light shielding layer LS may be formed. The light shielding layer LS may be arranged in an island shape spaced apart from the data line DL and the driving current line VDD by a predetermined distance and overlapping the semiconductor layers SA and DA, but is not limited thereto. As an example, the light shielding layer LS may overlap at least one of the semiconductor layers SA and DA or may be omitted according to the design. As an example, the light shielding layer LS may be floated or may be connected to the signal line. As an example, at least one of the data line DL, the driving current line VDD, and the light shielding layer LS may be formed on a different layer.

[0082] The buffer layer BUF is deposited on a surface (e.g., a portion of the surface or the entire surface) of the substrate 110, covering the data line DL and the driving current line VDD. A semiconductor layer SA of the switching thin film transistor ST and a semiconductor layer DA of the driving thin film transistor DT are formed on the buffer layer BUF. The switching thin film transistor ST and the driving thin film transistor DT are formed on the buffer layer BUF. Preferably, the channel regions in the semiconductor layers SA and DA at least partially overlap with the light shielding layer LS. The embodiment is not limited thereto. As an example, the semiconductor layer SA of the switching thin film transistor ST and the semiconductor layer DA of the driving thin film transistor DT may be formed on different layers.

[0083] The gate insulating layer GI is deposited on the substrate 110, covering the semiconductor layers SA and DA. A gate SG overlapping the semiconductor layer SA of the switching thin film transistor ST and a gate DG overlapping the semiconductor layer DA of the driving thin film transistor DT are formed on the gate insulating layer GI. In addition, a source electrode SS in contact with one side of the semiconductor layer SA and spaced apart from the gate SG and a drain electrode SD in contact with the other side of the semiconductor layer SA are formed on both sides of the gate SG of the switching thin film transistor ST. In addition, a source electrode DS in contact with one side of the semiconductor layer DA and spaced apart from the gate DG and a drain electrode DD in contact with the other side of the semiconductor layer DA are formed on both sides of the gate DG of the driving thin film transistor DT.

[0084] The gates SG and DG and the source-drain electrodes SS-SD and DS-DD are formed on the same layer, but are spatially and electrically separated from each other, but are not limited thereto. As an example, at least one of the gates SG and DG and the source-drain electrodes SS-SD and DS-DD may be formed on different layers. The source electrode SS of the switching thin film transistor ST may be connected to the data line DL via a contact hole penetrating the gate insulating layer GI. In addition, the drain electrode DD of the driving thin film transistor DT may be connected to the driving current line VDD via another contact hole penetrating the gate insulating layer GI.

[0085] The passivation layer PAS is deposited on the substrate 110, covering the thin film transistors ST and DT. The passivation layer PAS may be made of an inorganic material such as silicon oxide or silicon nitride, but is not limited thereto. In addition, according to an exemplary embodiment, the passivation layer 114 may be omitted.

[0086] The light emitting element layer 330 is formed on the driving element layer 220. The light emitting element layer 330 may include a reflective electrode REF, a partition wall WA, a planarization layer PL, a dam BA, and a light emitting diode OLE. A reflective electrode REF having a size corresponding to each pixel P is formed on the passivation layer PAS. As an example, the reflective electrode REF may have a size corresponding to the light emitting diode OLE. As an example, the size of the reflective electrode REF may be greater than, equal to, or less than the size of the light emitting diode OLE. As an example, the reflective electrode REF may have a size equal to or less than each pixel P. As an example, the reflective electrode REF may partially or completely overlap with the light emitting diode OLE. The reflective electrode REF may include a material having excellent light reflectivity (e.g., a metal material). For example, the reflective electrode REF may be formed of aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or an alloy thereof (i.e., aluminum-magnesium (Al / Mg)), but is not limited thereto.

[0087] The partition wall WA may be formed on the reflective electrode REF. The partition wall WA may preferably be formed of an inorganic material or an organic material. In this embodiment, the partition wall WA is formed of an organic material. The partition wall WA may cover the surrounding area of ​​the reflective electrode REF and expose most of the central area of ​​the reflective electrode REF. The central area of ​​the reflective electrode REF not covered by the partition wall WA may be defined as an emission area EA. The coverage area of ​​the partition wall WA may be defined as a non-emission area NEA.

[0088] The planarization layer PL is filled inside the area of ​​the light emitting area EA between the partition walls WA. The upper surface of the planarization layer PL may preferably form the same plane as the upper surface of the partition wall WA. As an example, the planarization layer PL may have a structure in which at least two refractive layers are stacked. For example, Figure 4As shown, the planarization layer PL may have a structure in which a first refractive layer B1 and a second refractive layer B2 are sequentially stacked. The embodiment is not limited thereto. As an example, the planarization layer PL may have a single layer or a structure of more than two layers, but is not limited thereto.

[0089] Specifically, the first refractive layer B1 may be formed on an exposed area (e.g., a central area) of the reflective electrode REF. The first refractive layer B1 may have a convex lens shape in which the bottom surface is flat but the middle portion of the upper surface is convex upward. The second refractive layer B2 may be stacked on the first refractive layer B1. The second refractive layer B2 has a flat upper surface. The lower surface of the second refractive layer B2 makes surface contact with the first refractive layer B1. Therefore, the second refractive layer B2 may have a concave lens shape in which the middle portion of the bottom surface is concave. However, the arrangement of the first refractive layer B1 and the second refractive layer B2 of the present disclosure is not limited thereto.

[0090] The cross-sectional shape (or profile) of the first refractive layer B1 may have a convex lens shape. Specifically, in the cross-sectional shape of the first refractive layer B1, the bottom surface has a straight plane profile, and the upper surface has a curved profile with a convex central portion. The cross-sectional shape of the second refractive layer B2 may have a concave lens shape. Specifically, in the cross-sectional shape of the second refractive layer B2, the upper surface has a straight plane profile, and the lower surface has a curved profile with a concave central portion.

[0091] The first refractive layer B1 and the second refractive layer B2 may be formed of materials different from each other (e.g., organic materials). For example, the first refractive layer B1 may be formed of a transparent organic material having a first refractive index. In addition, the second refractive layer B2 may be formed of a transparent organic material having a second refractive index different from the first refractive index. The first refractive index may be higher or lower than the second refractive index. In the present embodiment, the first refractive index may be lower than the second refractive index.

[0092] A pixel contact hole PH exposing a portion of the source electrode DS of the driving thin film transistor DT is formed in the passivation layer PAS and the planarization layer PL. The anode ANO may be formed on the upper surface of the partition wall WA and the planarization layer PL. As an example, the anode ANO may be formed on the entire upper surface of the planarization layer PL. As an example, the anode ANO may be formed on the entire upper surface of the planarization layer PL and a portion of the upper surface of the partition wall WA. The anode ANO may be connected to the source electrode DS of the driving thin film transistor DT via the pixel contact hole PH.

[0093] For example, Figure 4As shown, a first pixel contact hole PH1 may be formed at the passivation layer PAS. A reflective electrode REF formed on the passivation layer may be connected to a source electrode DS of the driving thin film transistor DT via the first pixel contact hole PH1. The reflective electrode REF may be covered by a planarization layer PL. A second pixel contact hole PH2 may be formed on the planarization layer PL. An anode ANO formed on the planarization layer PL may contact the reflective electrode REF via the second pixel contact hole PH2.

[0094] Although not shown in the figure, as an example, a pixel contact hole penetrating the passivation layer PAS, the planarization layer PL and the reflective electrode REF is formed to expose the source DS of the driving thin film transistor DT. In this case, the anode ANO formed on the planarization layer PL can be connected to the etched side surface of the reflective electrode REF and the upper surface of the source DS of the driving thin film transistor DT via the pixel contact hole. Although the anode ANO is shown to be electrically connected to (e.g., contacting) the reflective electrode REF, the embodiment is not limited thereto. As an example, the anode ANO may not be electrically connected to (e.g., not contacting) the reflective electrode REF. As an example, the pixel contact hole PH may not penetrate the reflective electrode REF. As an example, the anode ANO may be connected to the source DS of the driving thin film transistor DT by bypassing the reflective electrode REF.

[0095] Depending on the light-emitting type of the light-emitting diode OLE, the anode ANO may have different structures and configuration elements. For example, in the case of a bottom-emitting type that provides light in the direction of the substrate 110, the anode ANO may be formed of a transparent conductive material. As another example, in the case of a top-emitting type that provides light upward relative to the substrate 110, the anode ANO may be formed of a conductive material or any other conductive material having excellent light reflectivity. The light-emitting display device according to the present disclosure is a type of top-emitting type. The anode ANO may be formed of a transparent conductive material, and a reflective electrode REF formed of a metal material having excellent light reflectivity may be disposed below the anode ANO.

[0096] A levee BA is formed on the top surface of the substrate 110 having the anode ANO. The levee BA is preferably an insulating layer made of an inorganic material or an organic material. Hereinafter, a case where the levee BA is made of an inorganic material will be described. The levee BA covers the surrounding area of ​​the anode ANO and exposes most of the central area of ​​the anode ANO. The central area of ​​the anode ANO exposed from the levee BA is defined as the emission area EA, and the area covered by the levee BA is defined as the non-emission area NEA. As an example, the emission area EA defined by the levee BA may correspond to the emission area EA defined by the partition wall WA. As an example, the emission area EA defined by the levee BA may be the same as the emission area EA defined by the partition wall WA. As an example, the size of the emission area EA defined by the levee BA may be greater than, equal to, or less than the size of the emission area EA defined by the partition wall WA. As an example, the emission area EA defined by the levee BA may overlap with the emission area EA defined by the partition wall WA. Embodiments are not limited thereto.

[0097] Therefore, in a plan view, the anode ANO and the reflective electrode REF may have the same shape and size to be arranged to completely overlap each other. In addition, preferably the embankment BA may have the same shape and size as the partition wall WA, and may be arranged to completely overlap with the partition wall WA. In other cases, the reflective electrode REF may have a slightly larger size than the anode ANO, so that the anode ANO may be arranged in the area of ​​the reflective electrode REF. As an example, the exposed area of ​​the reflective electrode REF and the exposed area of ​​the anode ANO may have the same shape and size to be arranged to completely overlap each other. As an example, the exposed area of ​​the reflective electrode REF may be slightly larger than the exposed area of ​​the anode ANO.

[0098] The light-emitting layer EL is disposed on the anode ANO and the embankment BA. The light-emitting layer EL may be deposited on the entire display area AA of the substrate 110, covering the anode ANO and the embankment BA. For example, the light-emitting layer EL may include at least two light-emitting portions for generating white light. Specifically, the light-emitting layer EL may include a first light-emitting portion and a second light-emitting portion stacked vertically to generate white light by mixing a first light from the first light-emitting portion and a second light from the second light-emitting portion. Embodiments are not limited thereto. As an example, the light-emitting layer EL may generate light other than white light. As an example, the light-emitting layer EL may include one or more light-emitting portions.

[0099] As another example, the light emitting layer EL may include any one of a blue light emitting portion, a green light emitting portion, and a red light emitting portion to generate light corresponding to the color set in each pixel. In addition, the light emitting diode OLE may include a functional layer for improving the light emitting efficiency and / or life of the light emitting layer EL, but is not limited thereto.

[0100] The cathode CAT is deposited on the entire surface of the substrate 110 where the light emitting layer is formed. The cathode CAT is deposited to make surface contact with the light emitting layer EL. The cathode CAT is formed on the entire substrate 110 to be commonly connected to the light emitting layer EL deposited in all pixels. In the case of a top emission type, the cathode CAT may include a transparent conductive material. For example, the cathode CAT may be made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO), but is not limited thereto. Alternatively, the cathode CAT may include a thin metal such as aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or an alloy or combination thereof (for example, an aluminum-magnesium alloy (AlMg)). The cathode CAT may be formed with a thickness less than 100 mm. The cathode CAT is formed with a thin thickness of 100 Å to allow the cathode CAT to have a light-transmitting property, but is not limited thereto.

[0101] The encapsulation layer 440 is stacked on the light emitting element layer 330. The encapsulation layer 440 may have a single-layer structure made of an inorganic material, or a multi-layer structure in which a plurality of inorganic layers are sequentially stacked. As another example, the encapsulation layer 440 may have a structure in which an inorganic layer, an organic layer, and an inorganic layer are sequentially stacked. Figure 4 In the present invention, for the convenience of description, the encapsulation layer 440 made of a single inorganic layer will be used for explanation. The encapsulation layer 440 can prevent external moisture or oxygen from penetrating into the circuit element (particularly the light emitting element layer 330).

[0102] A color filter layer CF is stacked on the encapsulation layer 440. The color filter layer CF may be configured to assign one of a red color filter, a green color filter, and a blue color filter to one pixel P. As another example, the color filter layer CF may be configured to assign one of a red color filter, a white color filter, a green color filter, and a blue color filter to one pixel P. Hereinafter, for ease of description, the case where the color filter layer CF includes a red color filter CFR, a green color filter CFG, and a blue color filter CFB is used for illustration. Embodiments are not limited thereto. As an example, color filters for different colors may be included alternatively or additionally. As an example, the color filter layer CF may be omitted according to the design. As an example, a black matrix BM may be formed between adjacent color filters, or may be omitted according to the design.

[0103] The light emitting display device according to the first exemplary embodiment of the present disclosure has a structure in which a plurality of refractive layers are provided between the anode electrode ANO and the reflective electrode REF. Specifically, each of the plurality of refractive layers may have a different refractive index and a different cross-sectional shape from each other.

[0104] Specifically, the first refractive layer B1 and the second refractive layer B2 may be disposed between the anode electrode ANO and the reflective electrode REF. The first refractive layer B1 may include an organic material having a first refractive index, and the cross-sectional shape of the first refractive layer B1 may be a convex lens shape. The second refractive layer B2 may include an organic material having a second refractive index, and the cross-sectional shape of the second refractive layer B2 may be a concave lens shape.

[0105] like Figure 5A and Figure 5B As shown, the case where two layers having different refractive indices are provided exhibits different optical characteristics compared to the case where only one layer is provided. Figure 5A is a schematic diagram showing a light path in the case where a single transparent layer is provided between the anode and the reflective electrode. Figure 5B Schematic diagram showing an optical path in the case where two layers having different refractive indexes are provided between the anode and the reflective electrode.

[0106] Reference Figure 5A , among the light generated from the light emitting layer EL, the incident light ① traveling downward may enter the planarization layer PL through the anode ANO. The incident light ① passing through the planarization layer PL may be the reflected light ② of the reflective electrode REF, and may return to the anode ANO. Then, the reflected light ② passing through the anode ANO and the light emitting layer EL may be emitted from the display device. Here, when the light reflectivity of the reflective electrode REF is 90%, the light amount of the reflected light ② may be 90% of the incident light ①, and 10% may be lost.

[0107] Reference Figure 5B , among the light generated from the light emitting layer EL, the incident light ① traveling in the downward direction may enter the second refractive layer B2 of the planarizing layer PL through the anode ANO. A portion of the incident light ① reflected at the interface between the second refractive layer B2 and the first refractive layer B1 may be the first reflected light ②', which may return to the anode ANO. The other portion of the incident light ① may be the refracted light ③, which may enter the first refractive layer B1. Then, the refracted light ③ reflected by the reflective electrode REF may be the second reflected light ②", which may return to the anode ANO.

[0108] Here, the light reflectivity of the reflective electrode REF may be 90%, and the light reflectivity of the interface between the second refractive layer B2 and the first refractive layer B1 may be 30%. In this case, 30% of the incident light ① may be the first reflected light ②', and 70% of the incident light ① may be the refracted light ③. Thereafter, since 90% of the refracted light ③ may be the second reflected light ②", the second reflected light ②" may be 63% of the incident light ①. Therefore, the total reflected light may be 93% of the incident light ① (i.e., the sum of the first reflected light ②' and the second reflected light ②". Here, for convenience, the refraction of the second reflected light ②" at the interface between the second refractive layer B2 and the first refractive layer B1 is not considered.

[0109] In this way, when a plurality of refractive layers are stacked to form the planarization layer PL, reflectivity is higher than when the planarization layer PL includes a single layer, so that light extraction efficiency may be improved.

[0110] In addition, when the interface between the first refractive layer B1 and the second refractive layer B2 is a plane, total reflection may occur at the interface. The total reflected light may not return to the anode ANO, but may be captured inside the planarization layer PL, and thus eventually dissipated as heat energy. Figure 4 As shown, when the interface between the first refractive layer B1 and the second refractive layer B2 is a curved surface, the probability of total reflection can be significantly reduced. Therefore, the amount of light captured inside the planarization layer PL by total reflection between multiple refractive layers can be reduced or minimized, and the light extraction efficiency can be further improved.

[0111] <Second Exemplary Embodiment>

[0112] In the following, reference is made to Figure 6 , a second exemplary embodiment of the present disclosure will be described. Figure 6 is along Figure 3 The enlarged cross-sectional view taken along the line II-II' is used to illustrate the structure of three pixels sequentially arranged in the light-emitting display device according to the second exemplary embodiment of the present disclosure. Figure 6 In the description of the components below the driving component layer 220, Figure 4 The descriptions in are the same as those in , so the same descriptions will not be repeated or will be briefly given.

[0113] Reference Figure 6 , the structure of the light emitting display device according to the second exemplary embodiment of the present disclosure may be similar to that in the first exemplary embodiment. In the second exemplary embodiment, the planarization layer PL may include three refractive layers stacked.

[0114] Specifically, the light-emitting display device according to the second exemplary embodiment may include a substrate 110, a driving element layer 220, a light-emitting element layer 330, an encapsulation layer 440, and a color filter layer CF. The driving element layer 220 may include a plurality of film layers formed on the substrate 110. The driving element layer 220 may include a switching thin film transistor ST and a driving thin film transistor DT. Since the structure of the driving element layer 220 may be the same as that in the first exemplary embodiment, the same description may not be repeated or briefly given.

[0115] The reflective electrode REF having a size corresponding to each pixel P may be formed on the passivation layer PAS as the topmost layer of the driving element layer 220. The reflective electrode REF may be formed individually for each pixel P. The reflective electrode REF may include a metal material having excellent light reflectivity.

[0116] A partition wall WA may be formed on the reflective electrode REF. The partition wall WA may be made of an organic material. The partition wall WA may cover the periphery of the reflective electrode REF and expose most of the central portion of the reflective electrode REF.

[0117] The planarization layer PL may be filled inside the light emitting area EA between the partition walls WA. Preferably, the top surface of the planarization layer PL may be the same plane as the top surface of the partition wall WA. The planarization layer PL may include three refractive layers stacked sequentially.

[0118] Specifically, the first refractive layer B1 may be formed on the central portion of the reflective electrode REF exposed by the partition wall WA. The bottom surface of the first refractive layer B1 has a plane, but the middle portion of the upper surface of the first refractive layer B1 may be a curved surface in which the middle portion thereof is convex upward. The second refractive layer B2 may be formed on the first refractive layer B1. The upper surface of the second refractive layer B2 may have a curved shape in which the middle portion thereof is concave downward. The bottom surface of the second refractive layer B2 contacts the first refractive layer B1. Therefore, the second refractive layer B2 may have a concave lens shape in which the middle portion thereof is thinner than the peripheral portion. The top surface of the third refractive layer B3 has a plane. The bottom surface of the third refractive layer B3 contacts the second refractive layer B2. Therefore, the third refractive layer B3 may have a convex lens shape in which the middle portion thereof is convex downward.

[0119] The cross-sectional shape (or profile) of the first refractive layer B1 may have a convex lens shape. In the cross-sectional view of the first refractive layer B1, the bottom surface has a straight plane, and the top surface has a curved profile with a middle portion convex upward. The cross-sectional shape of the second refractive layer B2 may have a concave lens shape. In the cross-sectional view of the second refractive layer B2, the top surface has a curved surface with a middle portion concave downward, and the bottom surface has a curved surface profile with a middle portion concave upward. The cross-sectional shape of the third refractive layer B3 may have a convex lens shape. In the cross-sectional view of the third refractive layer B3, the top surface has a straight plane, and the bottom surface has a curved profile with a middle portion convex downward.

[0120] The first refractive layer B1, the second refractive layer B2, and the third refractive layer B3 may be made of different organic materials different from each other, but are not limited thereto. For example, the first refractive layer B1 may be made of a first transparent organic material having a first refractive index. The second refractive layer B2 may be made of a second transparent organic material having a second refractive index different from the first refractive index. In addition, the third refractive layer B3 may be made of a third transparent organic material having a third refractive index different from the first refractive index and the second refractive index. In one example, the first refractive index may be lower than the second refractive index, and the second refractive index may be lower than the third refractive index, but are not limited thereto. Although it is illustrated that the planarization layer PL may include three refractive layers stacked in sequence, the embodiment is not limited thereto. As an example, the planarization layer PL may include more than three refractive layers stacked in sequence. As an example, the three or more refractive layers may each have a convex lens shape or a concave lens shape. As an example, the three or more refractive layers may have refractive indices different from each other. As an example, the three or more refractive layers may have a refractive index that gradually decreases from top to bottom, but are not limited thereto.

[0121] A transparent anode ANO may be disposed on the third refractive layer B3. The light-emitting display device according to the present disclosure improves light extraction efficiency by causing light propagating downward from the light-emitting layer EL to be reflected at the interface of the multilayer structure before being reflected from the reflective electrode REF. Therefore, preferably, the third refractive index of the third refractive layer B3 may be different from the refractive index of the anode ANO, but is not limited thereto. In particular, the third refractive index may be lower than the refractive index of the anode ANO.

[0122] A bank BA may be formed on the surface of the substrate 110 having the anode ANO. The bank BA may be made of an inorganic material. Since the bank BA covers the periphery of the anode ANO, most of the middle portion of the anode ANO may be exposed. A light-emitting layer EL may be formed on the anode ANO and the bank BA. The light-emitting layer EL may be deposited on the entire display area AA of the substrate, covering the anode ANO and the bank BA.

[0123] The cathode CAT may be deposited on the entire surface of the substrate 110 having the light emitting layer EL. The cathode CAT may be stacked to make surface contact with the light emitting layer EL. The cathode CAT may be deposited on the entire surface of the substrate 110 to be commonly connected to the light emitting layer EL provided in all pixels.

[0124] An encapsulation layer 440 is disposed on the light emitting element layer 330. The encapsulation layer 440 may have a single-layer structure including an inorganic material or an organic material, or a multilayer structure in which a plurality of inorganic layers and / or organic materials are sequentially stacked. A color filter layer CF may be disposed on the encapsulation layer 440. The color filter layer CF may include a red color filter CFR, a green color filter CFG, and a blue color filter CFB. As an example, the color filter layer CF may be omitted.

[0125] In the second exemplary embodiment of the present disclosure, three refractive layers B1, B2, and B3 having different refractive indices are stacked between the anode ANO and the reflective electrode REF. Therefore, before light emitted downward from the light emitting layer EL reaches the reflective electrode REF, the light may be reflected at an interface between the anode ANO and the third refractive layer B3, an interface between the third refractive layer B3 and the second refractive layer B2, and an interface between the second refractive layer B2 and the first refractive layer B1. Therefore, the light extraction efficiency may be further improved compared to when the planarization layer PL is a single layer and compared to when the planarization layer PL includes two refractive layers.

[0126] Since the interface between the third refraction layer B3 and the second refraction layer B2 and the interface between the second refraction layer B2 and the first refraction layer B1 have a curved shape, the possibility of total reflection can be reduced or minimized. Therefore, the light extraction efficiency can be further improved.

[0127] <Third Exemplary Embodiment>

[0128] Reference Figure 7 , a third exemplary embodiment of the present disclosure will be described. Figure 7 is along Figure 3 The enlarged cross-sectional view taken along the line II-II' is used to illustrate the structure of three pixels sequentially arranged in the light-emitting display device according to the third exemplary embodiment of the present disclosure. Figure 7 The light emitting display device of the third exemplary embodiment shown may have Figure 6 The description of the same structure as the second exemplary embodiment may not be repeated or may be briefly given.

[0129] In the third exemplary embodiment, a plurality of silica nanoparticles SPC may be included in the planarization layer PL. In one example, the plurality of silica nanoparticles SPC may be dispersed in the first refractive layer B1, in the second refractive layer B2, and in the third refractive layer B3. In one example, the plurality of silica nanoparticles SPC may be dispersed in at least one of the first refractive layer B1, the second refractive layer B2, and the third refractive layer B3. Preferably, the plurality of silica nanoparticles SPC may be dispersed in all of the first refractive layer B1, the second refractive layer B2, and the third refractive layer B3.

[0130] The silica nanoparticles SPC can play a role in scattering light passing through the planarization layer PL. As a result, light emitted downward from the light emitting layer EL and light reflected upward from the reflective electrode REF are reduced or prevented from being captured in the planarization layer PL during passing through the planarization layer PL, thereby increasing the scattering effect of light. Therefore, compared with the case where the silica nanoparticles SPC are not provided, the light extraction effect can be further improved.

[0131] <Fourth Exemplary Embodiment>

[0132] In the following, reference is made to Figure 8 , a fourth exemplary embodiment of the present disclosure will be described. Figure 8 is along Figure 3 The enlarged cross-sectional view taken along the line II-II' is used to illustrate the structure of three pixels sequentially arranged in the light-emitting display device according to the fourth exemplary embodiment of the present disclosure. Figure 8 The light emitting display device of the fourth exemplary embodiment shown may have Figure 6 The description of the same structure as the second exemplary embodiment may not be repeated or may be briefly given.

[0133] In the fourth exemplary embodiment, the planarization layer PL may include a plurality of quantum dots corresponding to the color assigned to each pixel P. The quantum dots may be dispersed in at least one of the first refraction layer B1, the second refraction layer B2, and the third refraction layer B3. Preferably, the plurality of quantum dots may be dispersed in all of the first refraction layer B1, the second refraction layer B2, and the third refraction layer B3.

[0134] In one example, in the planarization layer PL disposed at the red pixel P_R, a plurality of second quantum dots QD2 may be dispersed to convert white light into red light. In the planarization layer PL disposed at the green pixel P_G, a plurality of first quantum dots QD1 may be dispersed to convert white light into green light. In addition, in the planarization layer PL disposed at the blue pixel P_B, a plurality of third quantum dots QD3 may be dispersed to convert white light into blue light.

[0135] Light emitted downward from the light emitting layer EL and reflected upward by the reflective electrode REF can be converted into colored light assigned to each pixel by the quantum dots assigned at each pixel P. Thereafter, the colored light can pass through the color filter layer CF, so that more accurately filtered colors can be achieved by the wavelength of the color band assigned to each pixel.

[0136] <Fifth Exemplary Embodiment>

[0137] In the following, reference is made to Fig. 9 , a fifth exemplary embodiment of the present disclosure will be described. Fig. 9 is along Figure 3 The enlarged cross-sectional view taken along the line II-II' is used to illustrate the structure of three pixels sequentially arranged in the light-emitting display device according to the fifth exemplary embodiment of the present disclosure. Fig. 9 The light-emitting display device of the fifth exemplary embodiment shown may have Figure 8 The description of the same structure as that of the fourth exemplary embodiment may not be repeated or may be briefly given.

[0138] Unlike the fourth exemplary embodiment, in the fifth exemplary embodiment, the color filter layer CF is not provided on the encapsulation layer 440. In the case where the color filter layer CF is provided, the accuracy or color rendering of each color can be improved, but the color filter layer CF may reduce the brightness. Therefore, when a display device with brighter brightness is required at the same driving power consumption, it is desirable to use the light-emitting display device according to the fifth exemplary embodiment, in which the color filter layer CF is removed from the light-emitting display device according to the fourth exemplary embodiment.

[0139] <Sixth Exemplary Embodiment>

[0140] In the following, reference is made to Fig.10 , a sixth exemplary embodiment of the present disclosure will be described. Fig.10 is along Figure 3 The enlarged cross-sectional view taken along the line II-II' is used to illustrate the structure of three pixels sequentially arranged in the light-emitting display device according to the sixth exemplary embodiment of the present disclosure. Fig.10 The light emitting display device of the sixth exemplary embodiment shown may have Fig. 9 The fifth exemplary embodiment shown has a very similar structure. The description of the same structure as the fourth exemplary embodiment may not be repeated or may be briefly given.

[0141] In the sixth exemplary embodiment, instead of the quantum dots of the fifth exemplary embodiment, a pigment or dye may be included in the planarization layer PL. The pigment or dye may be dispersed in at least one of the first refraction layer B1, the second refraction layer B2, and the third refraction layer B3. Preferably, the pigment or dye may be dispersed in all of the first refraction layer B1, the second refraction layer B2, and the third refraction layer B3. However, embodiments of the present disclosure are not limited thereto.

[0142] Specifically, a red pigment or red dye may be dispersed in a first planarization layer PL1 disposed at a red pixel P_R. A green pigment or green dye may be dispersed in a second planarization layer PL2 disposed at a green pixel P_G. In addition, a blue pigment or blue dye may be dispersed in a third planarization layer PL3 disposed at a blue pixel P_B.

[0143] In another case, a color filter layer CF may be further provided on the encapsulation layer 440. When the color filter layer CF is provided, the advantage is that the accuracy or color rendering of each color can be improved. However, the color filter layer CF may reduce the brightness. Therefore, when a display device with brighter brightness is required under the same driving power consumption, it is preferred to use Fig.10 A light emitting display device without a color filter layer CF is shown.

[0144] The light-emitting device according to one or more embodiments of the present disclosure can be applied to mobile devices, video phones, smart watches, watch phones, wearable devices, foldable devices, rollable devices, bendable devices, flexible devices, curved devices, variable devices, sliding devices, electronic notepads, e-books, portable multimedia players (PMPs), personal digital assistants (PDAs), MP3 players, mobile medical devices, desktop personal computers (PCs), laptop PCs, netbook computers, workstations, navigation devices, car navigation devices, car display devices, car devices, cinema devices, cinema display devices, televisions, wallpaper display devices, sign devices, game consoles, laptop computers, monitors, cameras, camcorders, home appliances, etc., but the embodiments of the present disclosure are not limited thereto.

[0145] The features, structures, effects, etc. described in the above exemplary embodiments of the present disclosure are included in at least the exemplary embodiments of the present disclosure, and are not necessarily limited to only the exemplary embodiments. In addition, the features, structures, effects, etc. described in at least the exemplary embodiments can be combined or modified by a person skilled in the art to which the present disclosure relates relative to other exemplary embodiments to achieve. Therefore, such combinations and variations should be interpreted as being included within the scope of the present disclosure.

[0146] It is obvious to those skilled in the art that various substitutions, modifications and variations can be made within the scope of the present disclosure without departing from the technical idea and scope of the present disclosure. Therefore, the embodiments of the present disclosure are intended to cover various substitutions, modifications and variations of the present disclosure, as long as they fall within the scope of the attached claims and their equivalents. According to the above detailed description, these and other changes can be made to the embodiments. Generally, in the attached claims, the terms used should not be interpreted as limiting the claims to the specific exemplary embodiments disclosed in the specification and the claims, but should be interpreted as including all possible embodiments and the full range of equivalents authorized by these claims. Therefore, the claims are not limited by the present disclosure.

[0147] CROSS-REFERENCE TO RELATED APPLICATIONS

[0148] This application claims priority to Korean Patent Application No. 10-2023-0082872, filed on Jun. 27, 2023, which is incorporated herein by reference as if fully set forth herein.

Claims

1. A light-emitting display device, comprising: substrate; A driving element layer, wherein the driving element layer is disposed on the substrate; A reflective electrode, wherein the reflective electrode is arranged on the driving element layer for each pixel; a partition wall covering the periphery of the reflective electrode and exposing a middle portion of the reflective electrode; a planarization layer filling an inner region surrounded by the partition wall and including a first refractive layer and a second refractive layer stacked on the first refractive layer; an anode, the anode being arranged on the planarization layer for each pixel; A light-emitting layer, wherein the light-emitting layer is disposed on the anode; as well as A cathode is disposed on the light-emitting layer.

2. The light-emitting display device according to claim 1, wherein: The lower surface of the second refractive layer contacts the surface of the first refractive layer.

3. The light-emitting display device according to claim 1, wherein: An interface between the first refractive layer and the second refractive layer has a curved surface.

4. The light-emitting display device according to claim 1, wherein: The first refractive layer has a first refractive index, and The second refractive layer has a second refractive index different from the first refractive index.

5. The light-emitting display device according to claim 4, wherein: The first refractive index is less than the second refractive index.

6. The light-emitting display device according to claim 1, wherein: The cross-sectional shape of the first refractive layer has a convex lens shape, and Wherein, the cross-sectional shape of the second refractive layer has a concave lens shape.

7. The light-emitting display device according to claim 1, wherein: An upper surface of the planarization layer is disposed at the same height as an upper surface of the partition wall.

8. The light-emitting display device according to claim 1, wherein: At least one of the first refractive layer and the second refractive layer includes a plurality of silicon dioxide nanoparticles.

9. The light-emitting display device according to claim 1, wherein: At least one of the first refraction layer and the second refraction layer includes a plurality of quantum dots for realizing a specific color.

10. The light-emitting display device according to claim 9, further comprising: an encapsulation layer, the encapsulation layer being disposed on the cathode; as well as A color filter layer is disposed on the encapsulation layer.

11. The light emitting display device according to claim 10, wherein: The planarization layer includes a plurality of quantum dots realizing colors corresponding to respective color filters of the color filter layer.

12. The light-emitting display device according to claim 1, wherein: The first refraction layer and the second refraction layer are formed of a transparent organic material.

13. The light-emitting display device according to claim 1, wherein: The anode is disposed on an upper surface of the planarization layer and an upper surface of the partition wall.

14. The light-emitting display device according to claim 1, further comprising: a bank covering the periphery of the anode and exposing a middle portion of the anode, The size of the middle portion of the anode electrode exposed by the bank is equal to or smaller than the size of the middle portion of the reflective electrode exposed by the partition wall.

15. The light emitting display device according to claim 1, wherein: The anode is connected to a driving thin film transistor in the driving element layer by penetrating the reflective electrode.

16. The light-emitting display device according to claim 1, wherein: The anode is electrically connected to the reflective electrode.

17. The light-emitting display device according to claim 1, wherein: The refractive index of the second refractive layer is lower than the refractive index of the anode.

18. The light emitting display device according to claim 1, wherein: The planarization layer further includes a third refractive layer stacked on the second refractive layer, Wherein, the interface between the second refractive layer and the third refractive layer has a curved surface, and The refractive index of the third refractive layer is smaller than the refractive index of the anode and larger than the refractive index of the second refractive layer.

19. The light-emitting display device according to claim 10, wherein: The color filter layer includes a red color filter at a red pixel, a green color filter at a green pixel, and a blue color filter at a blue pixel.

20. The light emitting display device according to claim 1, wherein: The planarization layer includes a red pigment at a red pixel, a green pigment at a green pixel, and a blue pigment at a blue pixel.

21. A pixel structure, comprising: Driver component layer; A reflective electrode, wherein the reflective electrode is located on the driving element layer; a partition wall covering the periphery of the reflective electrode and exposing a middle portion of the reflective electrode; a planarization layer filling an inner region surrounded by the partition wall and including a first refractive layer and a second refractive layer stacked on the first refractive layer; an anode, the anode being disposed on the planarization layer; A light-emitting layer, wherein the light-emitting layer is disposed on the anode; as well as A cathode is disposed on the light-emitting layer.

22. The pixel structure according to claim 21, wherein: An interface between the first refractive layer and the second refractive layer has a curved surface.

23. The pixel structure according to claim 21, wherein: The first refractive layer has a first refractive index, and The second refractive layer has a second refractive index greater than the first refractive index.

24. The pixel structure according to claim 21, further comprising: a bank covering the periphery of the anode and exposing a middle portion of the anode, The size of the middle portion of the anode electrode exposed by the bank is equal to or smaller than the size of the middle portion of the reflective electrode exposed by the partition wall.

25. The pixel structure according to claim 21, wherein: The planarization layer further includes a third refractive layer stacked on the second refractive layer, Wherein, the interface between the second refractive layer and the third refractive layer has a curved surface, and The refractive index of the third refractive layer is smaller than the refractive index of the anode and larger than the refractive index of the second refractive layer.

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