Light-emitting display device

Abstract

To provide a light-emitting display device capable of reducing or preventing a color difference due to a visual angle change at the time of a while color display, and capable of obtaining a stable view feeling.SOLUTION: A light-emitting display device contains: a substrate containing a first sub-pixel, a second sub-pixel, and a third sub-pixel; a red color light-emitting element that is provided to the first sub-pixel, and contains a red color light-emitting layer; and a blue color light-emitting element that is provided to the second sub-pixel, is provided to a green color light-emitting element containing a green-color light-emitting layer and the third sub-pixel, and contains the blue color light-emitting layer. A first wavelength difference between a light-emitting peak of the red color light-emitting layer and a light-emitting peak of the red color light-emitting element is 2nm or less. A second wavelength difference between the light-emitting peak of the green color light-emitting layer and the light-emitting peak of the green color light-emitting element is 2nm or less. A third wavelength difference between the blue light-emitting peak and the light-emitting peak of the blue light-emitting light element is 2nm or less, respectively.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a light-emitting display device that can prevent white color shift due to a change in viewing angle and prevent color shift between emitted colors from being visible. [Background technology]

[0002] 2. Description of the Related Art As the information society develops, the demands on display devices for displaying images increase in various ways.

[0003] A light-emitting display device in which pixels are formed by light-emitting elements does not require a separate light source unit, and is advantageous in that it can be made slimmer or more flexible, and also has the advantage of excellent color purity.

[0004] For example, a light-emitting device includes two electrodes and a light-emitting layer between them. When electrons generated from one electrode and holes generated from the other electrode are injected into the light-emitting layer, the injected electrons and holes combine to generate excitons, which then emit light as they fall from an excited state to a ground state. Summary of the Invention [Problem to be solved by the invention]

[0005] An organic EL display device may have a light-emitting layer that emits a different color for each sub-pixel. In this case, each sub-pixel has a different vertical distance between two electrodes facing each other, which induces an outcoupling effect. When displaying white, the organic EL display device turns on all light-emitting elements having different light-emitting layers to display white. In this case, due to the difference in vertical distance between the electrodes facing each other from adjacent sub-pixels, there is a problem that color deviation increases with changes in viewing angle when displaying white. [Means for solving the problem]

[0006] The present invention solves the above-mentioned problems and provides a light-emitting display device that can reduce or prevent color deviation due to changes in viewing angle when displaying white, thereby providing a stable visual impression.

[0007] An organic EL display device according to an embodiment of the present invention includes a substrate including first, second, and third sub-pixels, a red light emitting element including a red light emitting layer provided in the first sub-pixel, a green light emitting element including a green light emitting layer provided in the second sub-pixel, and a blue light emitting element including a blue light emitting layer provided in the third sub-pixel, wherein a first wavelength difference between an emission peak of light from the red light emitting layer and an emission peak of the red light emitting element may be 2 nm or less, a second wavelength difference between an emission peak of light from the green light emitting layer and an emission peak of the green light emitting element may be 2 nm or less, and a third wavelength difference between an emission peak of blue light and an emission peak of the blue light emitting element may be 2 nm or less. [Effects of the Invention]

[0008] The light emitting display device of the present invention has the following effects.

[0009] When the difference between the EL peak and PL peak wavelengths of the red, green, and blue light-emitting elements is 2 nm or less, and the maximum value of the color viewing angle distance of the emission colors from each light-emitting element is R>G>B, the color viewing angle distance from the white color that appears when all the red, green, and blue light-emitting elements are activated is 0.010 or less. As a result, when the light-emitting display device displays white, color deviation caused by changes in viewing angle can be minimized or reduced, and made invisible.

[0010] In addition, the vertical distance between the first and second electrodes is different for each light-emitting element, maximizing outcoupling characteristics. This structure reduces color viewing angle variability even in white, improving visibility regardless of changes in the viewing angle of the screen by the user.

[0011] In addition, the light emitting display device of the present invention can adjust the wavelength difference between the light emission peak and the electroluminescence peak by adjusting the thickness and material of the organic common layer including the light emitting layer and the light emitting element, and can manufacture a highly reliable light emitting display device without adding any additional materials, thereby reducing the environmental load, achieving low power consumption and process optimization, and achieving ESG (Environment / Social / Governance). [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a block diagram schematically illustrating a light-emitting display device according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view showing a light emitting device in which adjacent sub-pixels are arranged in a light emitting display device according to an embodiment of the present invention; [Figure 3] 3 is a cross-sectional view showing a light emitting display device to which the light emitting element of FIG. 2 is applied. [Figure 4] 4 is a graph showing an EL spectrum and a PL spectrum of light emitted from a red light-emitting element in a light-emitting display device of the present invention. [Figure 5] 10 is a graph showing an EL spectrum and a PL spectrum of light emitted from a green light-emitting element in a light-emitting display device of the present invention. [Figure 6] 4 is a graph showing an EL spectrum and a PL spectrum of light emitted from a blue light-emitting element in a light-emitting display device of the present invention. [Figure 7] 10 is a graph showing distances Δu'v' of the viewing angles of R, G, B, and W emitted light colors according to the viewing angle change in a light emitting display device according to the present invention. [Figure 8] 1 is a graph showing color coordinates according to a change in viewing angle in a light emitting display device according to an embodiment of the present invention. [Figure 9] 10 is a graph showing distances Δu'v' of viewing angles of R, G, B, and W emission colors according to viewing angle variations in a light emitting display device according to a comparative example. [Figure 10]10 is a cross-sectional view showing light emitting elements arranged in adjacent sub-pixels in a light emitting display device according to another embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The same reference numerals refer to substantially the same components throughout the specification. In the following description, if it is determined that a detailed description of a technology or configuration related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Furthermore, the component names used in the following description have been selected in consideration of ease of specification preparation and may differ from the part names of actual products.

[0014] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for illustrating various embodiments of the present invention are merely examples, and the present invention is not limited to the details shown in the drawings. The same reference numerals refer to the same elements throughout this specification. Furthermore, when describing the present invention, detailed descriptions of related prior art may be omitted if they are deemed not relevant to the gist of the present invention. When terms such as "include," "have," and "comprise" are used in this specification, other parts may be added unless "only" is used. When an element is expressed in the singular, it may also include the plural unless otherwise explicitly stated.

[0015] When interpreting the elements included in the various embodiments of the present invention, it is understood that a margin of error is included unless otherwise expressly stated.

[0016] In describing various embodiments of the present invention, when describing a positional relationship between two parts, for example, when the positional relationship between two parts is described as "above," "on top," "below," or "beside," one or more different parts may be located between the two parts unless "immediately" or "directly" is used.

[0017] In describing various embodiments of the present invention, when describing a time relationship, for example, when describing a time sequence using terms such as "after," "following," "next," or "before," the terms "immediately" or "directly" are not used, and therefore non-consecutive cases may also be included.

[0018] In describing various embodiments of the present invention, terms such as "first", "second", etc. are used to describe various components, but such terms are only used to distinguish between components that are identical or similar to each other. Therefore, a component modified as "first" in this specification may be the same as a component modified as "second" within the technical spirit of the present invention, unless otherwise specified.

[0019] The features of the various embodiments of the present invention may be partially or fully combined or combined with each other, and various technical interlocking and driving mechanisms may be possible. The various embodiments may be implemented independently of each other or may be implemented together in a related relationship.

[0020] As used herein, "doped" refers to a layer in which a material that occupies the majority of a given weight ratio is doped with a material that has different physical properties from the material that occupies the majority of the weight ratio. For example, "different physical properties" refers to materials that have N-type and P-type, organic and inorganic, at a weight ratio of less than 30%. In other words, a "doped" layer refers to a layer in which the host material and dopant material of a given layer can be distinguished based on their weight ratio. "Undoped" refers to all cases other than those that fall under the category of "doped." For example, if a layer is composed of a single material or a mixture of materials with similar properties, that layer is considered an "undoped" layer. For example, if at least one of the materials constituting a layer is P-type and all of the materials constituting that layer are not N-type, that layer is considered an "undoped" layer. For example, if at least one of the materials constituting a layer is organic and all of the materials constituting that layer are not inorganic, that layer is considered an "undoped" layer. For example, if all the materials constituting a layer are organic, and at least one of the materials constituting the layer is N-type and the other is P-type, the layer is considered "doped" if the N-type material is less than 30% by weight or the P-type material is less than 30% by weight.

[0021] Meanwhile, in this specification, the EL electroluminescence spectrum is the product of (1) the PL (photoluminescence) spectrum, which reflects the inherent characteristics of the luminescent materials, such as the dopant material and the host material, contained in the organic emitting layer, and (2) the outcoupling emittance spectrum curve, which is determined by the structure and optical characteristics of the organic light emitting device, including the thicknesses of the organic layers, such as the hole transport layer and the electron transport layer.

[0022] FIG. 1 is a block diagram schematically showing a light-emitting display device according to the present invention.

[0023] Hereinafter, a light-emitting display device and a manufacturing method thereof according to the present specification will be described with reference to the drawings.

[0024] FIG. 1 is a block diagram illustrating a light emitting display device according to an embodiment of the present invention.

[0025] As shown in FIG. 1, a light emitting display device 1000 according to an embodiment of the present invention may include a display panel 11, an image processor 12, a timing controller 13, a data driver 14, a scan driver 15, and a power supply 16.

[0026] The display panel 11 can display an image in response to a data signal DATA supplied from a data driver 14 , a scan signal supplied from a scan driver 15 , and power supplied from a power supply 16 .

[0027] The display panel 11 may include sub-pixels SP arranged at each intersection of a plurality of gate lines GL and a plurality of data lines DL. The structure of the sub-pixels SP may be variously changed depending on the type of the light emitting display device 1000.

[0028] For example, the subpixels SP may be formed in a top emission, bottom emission, or dual emission mode depending on their structure. The subpixels SP are units that can emit their own color with or without a specific type of color filter. For example, the subpixels SP may include red, green, and blue subpixels. Alternatively, the subpixels SP may include red, blue, white, and green subpixels. The subpixels SP may have one or more different emission areas depending on their emission characteristics. For example, a subpixel that emits a color different from that of a blue subpixel may have a different emission area.

[0029] One or more subpixels SP may constitute one unit pixel. For example, one unit pixel may include red, green, and blue subpixels, and the red, green, and blue subpixels may be arranged alternately. Alternatively, one unit pixel may include red, green, blue, and white subpixels, and the red, green, blue, and white subpixels may be arranged alternately, or the red, green, blue, and white subpixels may be arranged in a quad configuration. In the embodiments of the present specification, the color type, arrangement type, and arrangement order of the subpixels may be configured in various forms depending on the light-emitting characteristics, device life, device specifications, etc., and are not limited thereto.

[0030] The display panel 11 is divided into a display area AA (inside the dotted line area) where sub-pixels SP are arranged and display an image, and a non-display area NA around the display area AA. The scan driver 15 may be mounted in the non-display area NA of the display panel 11. The non-display area NA may also include a pad unit including pad electrodes PD.

[0031] Here, the display area AA is also called an active area, and the non-display area NA is also called an inactive area.

[0032] The image processor 12 may output a data enable signal DE along with an externally supplied data signal DATA. In addition to the data enable signal DE, the image processor 12 may also output one or more of a vertical sync signal, a horizontal sync signal, and a clock signal, although these signals are not shown in the drawings for the sake of convenience.

[0033] The timing controller 13 may receive a data signal DATA along with a driving signal from the video processor 12. The driving signal may include a data enable signal DE. Alternatively, the driving signal may include a vertical synchronization signal, a horizontal synchronization signal, and a clock signal. Based on the driving signal, the timing controller 13 may output a data timing control signal DDC for controlling the operation timing of the data driver 14 and a gate timing control signal GDC for controlling the operation timing of the scan driver 15.

[0034] The data driver 14 samples and latches the data signal DATA supplied from the timing controller 13 in response to the data timing control signal DDC supplied from the timing controller 13, converts it into a gamma reference voltage, and outputs it.

[0035] The data driver 14 may output a data signal DATA through the data line DL. The data driver 14 may be configured in the form of an integrated circuit (IC). For example, the data driver 14 may be electrically connected to a pad electrode PD disposed in the non-display area NA of the display panel 11 via a flexible circuit film (not shown).

[0036] The scan driver 15 may output a scan signal in response to a gate timing control signal GDC provided from the timing controller 13. The scan driver 15 may output the scan signal through the gate line GL. The scan driver 15 may be configured in the form of an integrated circuit (IC) or may be configured in the display panel 11 in a gate-in-panel (GIP) manner.

[0037] The power supply unit 16 can output a high potential voltage, a low potential voltage, and the like for driving the display panel 11. The power supply unit 16 can supply the high potential voltage to the display panel 11 via a first power supply line EVDD (a driving power supply line or a pixel power supply line) and can supply the low potential voltage to the display panel 11 via a second power supply line EVSS (an auxiliary power supply line or a common power supply line).

[0038] The display panel 11 is divided into a display area AA and a non-display area NA, and may include a plurality of sub-pixels SP defined by gate lines GL and data lines DL that intersect with each other and are formed in a matrix within the display area AA.

[0039] The sub-pixels SP may include sub-pixels that emit at least two or more of red light, green light, blue light, yellow light, magenta light, and cyan light.

[0040] In addition, the plurality of sub-pixels SP may be formed with a specific type of color filter or may emit their own color without a color filter, but the present invention is not necessarily limited thereto, and the sub-pixels SP may be configured in various forms, such as color type, arrangement type, and arrangement order, depending on the light-emitting characteristics, device life, and device specifications.

[0041] Each of the sub-pixels SP may include a light-emitting portion from which light is emitted and a non-light-emitting portion surrounding the light-emitting portion.

[0042] Hereinafter, an organic EL display device in which light emitting elements including light emitting layers for emitting corresponding colors are applied to red, green, and blue sub-pixels according to an embodiment of the present invention will be described with reference to the drawings.

[0043] 2 is a cross-sectional view showing a light emitting device in which adjacent sub-pixels are arranged in a light emitting display device according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view showing a light emitting display device to which the light emitting device of FIG. 2 is applied.

[0044] Fig. 4 is a graph showing the EL spectrum and PL spectrum of light emitted from a red light-emitting element in a light-emitting display device of the present invention. Fig. 5 is a graph showing the EL spectrum and PL spectrum of light emitted from a green light-emitting element in a light-emitting display device of the present invention. Fig. 6 is a graph showing the EL spectrum and PL spectrum of light emitted from a blue light-emitting element in a light-emitting display device of the present invention.

[0045] As shown in Figures 2 and 3, an organic emissive display device 1000 according to an embodiment of the present invention includes a substrate 100 including a first sub-pixel R_SP, a second sub-pixel G_SP, and a third sub-pixel B_SP, and organic emissive elements RED, GED, and BED provided in each sub-pixel on the substrate.

[0046] More specifically, the light emitting display device 1000 according to one embodiment of the present invention includes a red light emitting element RED provided in the first sub-pixel R_SP and including first and second red light emitting layers 143, 163, a green light emitting element GED provided in the second sub-pixel G_SP and including first and second green light emitting layers 142, 162, and a blue light emitting element BED provided in the third sub-pixel B_SP and including first and second blue light emitting layers 141, 161. In the light-emitting display device according to Figures 2 and 3, each light-emitting element RED, GED, BED includes a charge generation layer CGL between the first and second electrodes 120, 175, a lower stack between the first electrode 120 and the charge generation layer CGL, and an upper stack between the charge generation layer CGL and the second electrode 175.

[0047] Specifically, the red light-emitting element RED includes two stacks separated by a charge generation layer CGL between the first electrode 120 and the second electrode 175. The lower stack of the red light-emitting element RED includes a hole injection layer 131, a first hole transport layer 132, a first red light-emitting layer 143, and a first electron transport layer 151. The upper stack of the red light-emitting element RED includes a second hole transport layer 154, a first hole transport compensation layer 156, a second red light-emitting layer 163, and a second electron transport layer 171.

[0048] 2 includes a hole injection layer 131, a first hole transport layer 132, a first green light-emitting layer 142, and a first electron transport layer 151. The upper stack of the green light-emitting element GED includes a second hole transport layer 154, a second hole transport compensation layer 157, a second green light-emitting layer 162, and a second electron transport layer 171.

[0049] 2 includes a hole injection layer 131, a first hole transport layer 132, a first blue light-emitting layer 141, and a first electron transport layer 151. The upper stack of the blue light-emitting element BED includes a second hole transport layer 154, a second blue light-emitting layer 161, and a second electron transport layer 171.

[0050] The first red light-emitting layer 143 and the second red light-emitting layer 163 overlap each other in the first sub-pixel R_SP, the first green light-emitting layer 142 and the second green light-emitting layer 162 overlap each other in the second sub-pixel R_SP, and the first blue light-emitting layer 141 and the second blue light-emitting layer 161 overlap each other in the third sub-pixel B_SP.

[0051] Additionally, a charge generation layer CGL is further included between the lower stack and the upper stack, which includes an n-type charge generation layer 152 and a p-type charge generation layer 153. The n-type charge generation layer 152 generates electrons and supplies and transfers them to the lower stack, while the p-type charge generation layer 153 generates holes and supplies and transfers them to the upper stack. In some cases, the n-type charge generation layer 152 and the p-type charge generation layer 153 may be formed as a single layer.

[0052] All layers included between the first electrode 120 and the second electrode 175 are collectively referred to as the intermediate layer OS (FIG. 3), and all layers included in the intermediate layer OS may be formed containing organic materials. In some cases, some layers may contain small amounts of inorganic materials as dopants for electron transport, hole transport, mobility, or light emission control.

[0053] Meanwhile, in an emissive display device according to one embodiment of the present invention, the hole injection layer 131, the first hole transport layer 132, the first electron transport layer 151, the charge generation layer CGL, the second hole transport layer 154, and the second electron transport layer 171 are commonly provided in each of the light emitting elements RED, GED, and BED, and in this respect can be referred to as common layers.

[0054] The red light emitting element RED, the green light emitting element GED, and the blue light emitting element BED have different vertical distances between the first electrode 120 and the second electrode 175 to obtain different out-coupling characteristics according to the wavelength of each emitted color. To achieve different vertical distances between the first and second electrodes 120 and 175, the red light emitting element RED and the green light emitting element GED may have first and second hole transport compensation layers 156 and 157 with different thicknesses, respectively.

[0055] Here, the first hole transport compensation layer 156 and the second hole transport compensation layer 157 may be disposed in either the lower stack or the upper stack, and may be disposed in contact with each hole transport layer in the lower stack or the upper stack. In the example of FIG. 2, the first and second hole transport compensation layers 156 and 157 are disposed in the upper stack. The first and second hole transport compensation layers 156 and 157 may be formed of an organic material having the same or similar energy band gap characteristics as the first and second hole transport layers 132 and 154. However, the present invention is not limited thereto.

[0056] Meanwhile, in an organic light emitting display device according to an embodiment of the present invention, the first electrode 120 may include a reflective electrode, and the second electrode 175 may be a semi-transparent electrode or a transparent electrode. A capping layer 180 may be further provided on the second electrode 175 to protect the red, green, and blue light emitting elements RED, GED, and BED and to increase the emission efficiency of light emitted from the second electrode 175. The capping layer 180 may include either an organic capping layer or an inorganic capping layer. The capping layer 180 may be formed by stacking a plurality of capping layers having different refractive indices to maximize the emission effect. There are times when

[0057] The first electrode 120 may include a reflective electrode, and the second electrode (cathode) may include a transparent electrode or a reflective / transmissive electrode. For example, when the first electrode (anode) includes a reflective electrode, the first electrode (anode) may be formed as a multilayer structure including a transparent conductive film and an opaque conductive film with high reflective efficiency. The transparent conductive film of the first electrode (anode) is made of a material with a relatively high work function, such as indium tin oxide (ITO) or indium zinc oxide (IZO), and the opaque conductive film is made of an alloy selected from the group consisting of silver (Ag), magnesium (Mg), aluminum (Al), copper (Cu), molybdenum (Mo), titanium (Ti), nickel (Ni), chromium (Cr), and tungsten (W). For example, the first electrode (anode) may be formed as a structure in which a transparent conductive film, an opaque conductive film, and a transparent conductive film are sequentially stacked, or a structure in which a transparent conductive film and an opaque conductive film are sequentially stacked. As an example, the first electrode (anode) may include a laminated structure of ITO / APC (Ag-Pd-Cu) / ITO.

[0058] The second electrode (cathode) may be made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO), or may be made of silver (Ag), aluminum (Al), magnesium (Mg), calcium (Ca), ethabium (Yb), or an alloy containing at least one of these, thin enough to transmit light. When the second electrode (cathode) is made of a metal or metal alloy thin enough to transmit light, the second electrode (cathode) has reflective / transmissive properties, and light resonating between the first electrode (anode) and the second electrode (cathode) has strong cavity properties and can transmit through the second electrode (cathode).

[0059] Meanwhile, in the light emitting display device according to one embodiment of the present invention, the thicknesses of the first and second red light emitting layers 143, 163, the first and second green light emitting layers 142, 162, and the first and second blue light emitting layers 141, 161 adjacent to the red light emitting element RED, the green light emitting element GED, and the blue light emitting element BED may be different to vary the optical distance.

[0060] The red light emitting element RED, the green light emitting element GED, and the blue light emitting element BED each include a first electrode 120 and a second electrode 175 facing each other, and the first and second red light emitting layers 143, 163, the first and second green light emitting layers 142, 162, and the first and second blue light emitting layers 141, 161 are included between the first electrode 120 and the second electrode 175. In addition, the red light emitting element RED, the green light emitting element GED, and the blue light emitting element BED have different vertical distances between the inner surface of the first electrode 120 (the surface in contact with the electron injection layer 131) and the inner surface of the second electrode 175 (the electron transport layer 171), and thus the difference in vertical distance between the first and second electrodes 120, 175 may result in maximum outcoupling characteristics for each emission color.

[0061] The maximum outcoupling characteristics can be obtained when light generated from the light-emitting layer between the first and second electrodes 120, 175 of each light-emitting element is reflected and re-reflected on the inner surfaces of the first and second electrodes 120, 175, and then emitted as a maximum light through constructive interference. The red light-emitting element RED may have a maximum emission peak at a wavelength of 600 nm to 650 nm, the green light-emitting element GED may have a maximum emission peak at a wavelength of 500 nm to 590 nm, and the blue light-emitting element BED may have a maximum emission peak at a wavelength of 420 nm to 490 nm. In other words, the red, green, and blue light-emitting elements have different wavelengths at which their respective maximum emission peaks occur, and therefore the vertical distance between the first and second electrodes 125, 175 required for outcoupling characteristics through constructive interference differs.

[0062] In a conventional structure in which different color light-emitting layers are used for each sub-pixel to express the color of the sub-pixel, a light-emitting element with a difference in the vertical distance between the first and second electrodes is included, and although this structure improves outcoupling characteristics in a front structure, it is sensitive to changes in viewing angle, which can cause issues with visibility of color differences.

[0063] The light emitting display device of the present invention can solve the color deviation caused by the change in the viewing angle, and can prevent the color change that occurs depending on the viewing angle, particularly when displaying white.

[0064] In the light emitting display device of the present invention, as shown in FIG. 4, a first wavelength difference (Red Plmmax - ELmmax) between the photoluminescence (PL) peak (PLλmax) of the red light emitting layer and the electroluminescence (ELλmax) peak of the red light emitting element may be 2 nm or less. As shown in FIG. 5, a second wavelength difference (Green Plλmax - ELpm) between the photoluminescence (PL) peak of the green light emitting layer and the electroluminescence (EL) peak of the green light emitting element may be 2 nm or less. As shown in FIG. 6, a third wavelength difference (Green Plλmax - ELλmax) between the photoluminescence peak (PL peak) of the blue light emitting layer and the electroluminescence (EL peak) peak of the blue light emitting element may each be 2 nm or less. This reduces color deviation of each emission color even when the viewing angle is changed when a viewer views the light emitting display device. Furthermore, this minimizes or reduces color viewing angle deviation of white light obtained by combining red light from the red light emitting element, green light from the green light emitting element, and blue light from the blue light emitting element.

[0065] Meanwhile, the PL spectrum of the light emitting layer is a characteristic determined by the materials (dopants and hosts) inherent to the light emitting layer, and the electroluminescence spectrum (EL spectrum) of the light emitting device is determined by the product of the light emission spectrum curve and the outcoupling emittance spectrum curve, which is determined by the thickness and materials of the entire organic layers included in the entire light emitting device structure.

[0066] 4, the red light-emitting layer of the red light-emitting device of the light-emitting display device of the present invention has a PL peak at a wavelength of approximately 610 nm to 625 nm, and the EL spectrum of the red light-emitting device is generated by adjusting the materials and thicknesses of organic layers 131, 132, 143, 151, 152, 153, 154, 156, 163, and 171 included in the entire red light-emitting device to generate a red EL spectrum having an electroluminescence peak (EL peak) with a wavelength difference of 2 nm or less from the red emission peak (PL peak). First and second red light-emitting layers 143 and 163 each contain a red phosphorescent dopant containing a heavy metal such as iridium or platinum, and may contain at least one of a hole-transporting host and an electron-transporting host.

[0067] 5, the green light-emitting layer of the green light-emitting device of the present invention has a PL peak at a wavelength of approximately 525 nm to 540 nm, and the EL spectrum of the green light-emitting device is generated by adjusting the thicknesses and components of organic layers 131, 132, 142, 152, 153, 154, 156, 163, and 171 included in the entire green light-emitting device to generate a green EL spectrum having an electroluminescence peak (EL peak) at a wavelength difference of 2 nm or less from the green emission peak (PL peak). First and second green light-emitting layers 142 and 162 each contain a green phosphorescent dopant containing a heavy metal such as iridium or platinum, and may contain at least one of a hole-transporting host and an electron-transporting host.

[0068] 6, the blue light-emitting layer of the blue light-emitting device of the light-emitting display device of the present invention has a PL peak at a wavelength of approximately 450 nm to 470 nm, and the EL spectrum of the blue light-emitting device is generated by adjusting the materials and thicknesses of organic layers 131, 132, 141, 152, 153, 154, 156, 163, and 171 included in the entire blue light-emitting device to generate an EL spectrum having an electroluminescence peak (EL peak) with a wavelength difference of 2 nm or less from the emission peak (PL peak) wavelength of the blue light-emitting layer. The first and second blue light-emitting layers 141 and 161 each contain a boron-based fluorescent or TADF (Thermal Activated Delayed Fluorescence) blue dopant and may contain at least one host.

[0069] 2, in an organic EL display device according to an embodiment of the present invention, common layers 131, 132, 151, 152, 153, 154, and 171 included in blue light emitting device BED are commonly formed in green light emitting device GED and red light emitting device RED. Therefore, first, the wavelength difference between the blue PL peak due to the materials of first and second blue light emitting devices 141 and 161 of blue light emitting device BED and the blue EL peak due to the thickness and material of common layers 131, 132, 151, 152, 153, 154, and 171 is adjusted to be 2 nm or less. Then, the wavelength difference between the green light emission peak (PL peak) and the green electroluminescence peak (EL peak) may be adjusted to be 2 nm or less, and the wavelength difference between the red light emission peak (PL peak) and the red electroluminescence peak (EL peak) may be adjusted to be 2 nm or less by adjusting the thicknesses and compositions of light emitting layers 142 / 162, 143 / 163 and first and second hole transport assisting layers 156 and 157 of each light emitting device.

[0070] For this reason, the first and second red light emitting layers 143 and 163, the first and second green light emitting layers 142 and 162, and the first and second blue light emitting layers 141 and 161 may have different thicknesses.

[0071] Furthermore, the first and second hole transport assistance layers 156 and 157 may have different thicknesses.

[0072] The following describes the configuration not described in FIG.

[0073] The light emitting display device 1000 shown in FIG. 3 shows a connection between the thin film transistor TFT and the first electrode 120 of the light emitting element ED on the substrate 100.

[0074] The substrate 100 may include at least one of glass, a plastic film, and a metal film.

[0075] The light-emitting elements ED are connected to thin film transistors TFT. For example, as shown in Fig. 3, the thin film transistors TFT include a semiconductor layer 103, a gate electrode 105 overlapping the channel of the semiconductor layer 103 with a gate insulating film 104 sandwiched therebetween, and a source electrode 106 and a drain electrode 107 connected to the semiconductor layer 103.

[0076] The substrate 100 may include at least one of glass, a plastic film, and a metal film.

[0077] The light-emitting elements ED are connected to thin film transistors TFT. For example, as shown in Fig. 3, the thin film transistors TFT include a semiconductor layer 103, a gate electrode 105 overlapping the channel of the semiconductor layer 103 with a gate insulating film 104 sandwiched therebetween, and a source electrode 106 and a drain electrode 107 connected to the semiconductor layer 103.

[0078] The source electrode 106 or the drain electrode 107 of the semiconducting layer 103 may be connected to the first electrode 120 .

[0079] The semiconductor layer 103 may include at least one of an oxide semiconductor, amorphous silicon, and crystalline silicon.

[0080] A light-shielding layer 101 may be further provided below the semiconductor layer 103 to prevent light entering from the underside of the substrate 100 from affecting the semiconductor layer 103 .

[0081] A buffer layer 102 may further be provided between the light-shielding layer 101 and the semiconductor layer 103 .

[0082] To protect the thin film transistor TFT, an inorganic protective film 108 and an organic protective film 109 may be formed in this order.

[0083] The buffer layer 102 and the inorganic protective film 108 may be, for example, any of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a metal oxide film, and a metal nitride film.

[0084] The organic protective layer 109 may be made of an organic material such as photoacrylic or BCB, and may have a flat upper surface.

[0085] 3, the hole injection / transport unit 130 including the hole injection layer 131 and the first hole transport layer 132 of FIG. 2 is expressed as a single structure, and the inter-stack carrier transport unit 150 including the first electron transport layer 151, the charge generation layer (CGL; 152 / 153), and the second hole transport layer 154 is expressed as a single structure. In the light emitting display device of the embodiment of the present invention, the common layers of the hole injection / transport unit 130, the carrier transport unit 150, and the second electron transport layer 171 may each be a plurality of layers greater than those shown in FIG.

[0086] Additionally, the second electron transport layer 171 may further include an electron injection layer adjacent to the second electrode 175 .

[0087] Meanwhile, the light emitting display device of the present invention is characterized by not only the PL peak-EL peak characteristics of the individual light emitting elements and each light emitting layer as described above, but also by minimizing color perception due to viewing angle fluctuations when all of the red, green, and blue light emitting elements are turned on to emit white light.

[0088] Figure 7 is a graph showing the color viewing angle distance (△u'v') of each emission color (R, G, B, W) as a function of viewing angle variation in a light emitting display device according to the present invention. Figure 8 is a graph showing color coordinates as a function of viewing angle variation in a light emitting display device according to the present invention. Figure 9 is a graph showing the color viewing angle distance (△u'v') of each emission color (R, G, B, W) as a function of viewing angle variation in a light emitting display device according to a comparative example.

[0089] [Table 1]

[0090] When red, green, and blue light-emitting elements are designed to have the PL peak-EL peak characteristics shown in FIGS. 4 to 6, the white light W obtained by combining the red light from the red light-emitting element and the blue light from the green light-emitting element, as shown in FIG. 7 and Table 1, can have a color viewing angle distance Δu'v' of 0.010 or less at a viewing angle of 60° or less.

[0091] Among the distance Δu'v' of the first color viewing angle of red light R in a red light-emitting element, the distance Δu'v' of the second color viewing angle of green light G in a green light-emitting element, and the distance Δu'v' of the third color viewing angle of blue light B in a blue light-emitting element, the maximum value of the distance of the red first color viewing angle (RmaxΔu'v') may be the largest and the maximum value of the distance of the blue third color viewing angle (BmaxΔu'v) may be the smallest at viewing angles of 60° or less. That is, as shown in FIG. 7, the relationship between the maximum distance of the red first color viewing angle, the maximum distance of the green first color viewing angle, and the maximum distance of the blue third color viewing angle is (RmaxΔu'v'>GmaxΔu'v'>BmaxΔu'v').

[0092] The maximum value of the distance of the red first color viewing angle (RmaxΔu'v') occurs at a viewing angle of 45° to 60°, and the maximum value of the distance of the second color viewing angle (GmaxΔu'v') and the maximum value of the distance of the third color viewing angle (BmaxΔu'v') occur at a viewing angle of 30° to 60°.

[0093] The first color viewing angle distance (RΔu'v') of red light from a red light-emitting element, the second color viewing angle distance (GΔu'v') of green light from a green light-emitting element, and the third color viewing angle distance (BΔu'v') of blue light from a blue light-emitting element can each be greater than the fourth color viewing angle distance (WΔu'v') of white light, which is a combination of red light from a red light-emitting element, green light, and blue light from a blue light-emitting element, at the same viewing angle.

[0094] Regarding the first-color viewing angle distance (RΔu'v') of red light from a red light-emitting element, the second-color viewing angle distance (GΔu'v') of green light from a green light-emitting element, and the third-color viewing angle distance (BΔu'v') of blue light from a blue light-emitting element, the first-color viewing angle distance (RΔu'v') may be largest and the third-color viewing angle distance BΔu'v' may be smallest at viewing angles of 20° to 60°. Alternatively, the first-color viewing angle distance (RΔu'v') may be larger than the second-color viewing angle (GΔu'v') and the third-color viewing angle distance BΔu'v' at viewing angles of 20° to 60°. Furthermore, the first-color viewing angle distance (RΔu'v') may be smaller than the second-color viewing angle distance (GΔu'v') and the third-color viewing angle distance (BΔu'v') at viewing angles of 0° to 20°.

[0095] As shown in Figures 4 to 6, when the difference between the EL peak and PL peak wavelengths of the red, green, and blue light-emitting elements is 2 nm or less, and when the maximum value of the color viewing angle distance between the colors emitted from each light-emitting element is R>G>B as shown in Figure 7, the color viewing angle distance between the color emitted from each light-emitting element and the white color emitted when all the red, green, and blue light-emitting elements are activated is 0.010 or less. As a result, color deviation caused by changes in viewing angle when displaying white in an emissive display device can be minimized or reduced, or made invisible.

[0096] When the relationship between ELλmax and PLλmax emitted by each pixel to display white has a wavelength difference of a certain value or less, and the maximum values ​​of the distances (△u'v') between the viewing angles of each emitted color are satisfied in the order of R>G>B, the white viewing angle variation range can be improved.

[0097] 8 shows the color coordinates of 15°, 30°, 45°, and 60° in the 1976 color coordinate system (u', v') when the viewing angle is increased by 15° from 0° during white display. Referring to FIG. 8, it can be seen that the difference between the starting point of 0° and the viewing angle of 45° is greatest, and the end point of 60° approaches the starting point of 0°. This means that when displaying white in the light-emitting display device of the present invention, the color deviation at the viewing angle of 60° is smaller than that at the viewing angle of 45°.

[0098] 7 and Table 1, it can be seen that the color coordinates of white in the light emitting display device of the present invention are less than 0.010 at a viewing angle of 60° or less, and that the user hardly notices any color deviation when white is displayed.

[0099] [Table 2]

[0100] 9, in the comparative example of the light-emitting display device in which the wavelength difference between the EL peak and the PL peak of the blue light-emitting element exceeds 2 nm among the red, green, and blue light-emitting elements, the color viewing angle distance (△u'v') for blue increases sharply at viewing angles of 40° or more, exceeding 0.080 at a viewing angle of 60°. In addition, the color viewing angle distance (△u'v') for white is close to 0.032 at viewing angles of 40° or more, confirming that color deviation occurs due to changes in viewing angle when white is displayed.

[0101] 2 and 3 are described as having a two-stack structure, the light emitting display device of the present invention is not limited to such a two-stack structure. At least one of the light emitting devices may have a three-stack or more structure by further including a charge generation layer and an additional stack to increase the efficiency of each light emitting device.

[0102] Furthermore, as described below, even in a structure having a single stack of light-emitting elements, the EL peak-PL peak wavelength difference for each light-emitting element of the present invention is limited, and the distance characteristics of the viewing angle for each emission color are defined, thereby minimizing or reducing color deviation due to viewing angle fluctuation when displaying white in an emissive display device, and preventing the color deviation from being visible.

[0103] FIG. 10 is a cross-sectional view showing light emitting elements arranged in adjacent sub-pixels in a light emitting display device according to another embodiment of the present invention.

[0104] As shown in FIG. 10, each light emitting element of the light emitting display device according to another embodiment of the present invention may have a single stack structure.

[0105] That is, as shown in FIG. 10, an emissive display device according to another embodiment of the present invention includes a red light emitting element RED provided in the first sub-pixel R_SP and including a red light emitting layer 247, a green light emitting element GED provided in the second sub-pixel G_SP and including a green light emitting layer 246, and a blue light emitting element BED provided in the third sub-pixel B_SP and including a blue light emitting layer 245.

[0106] Each of the light-emitting elements RED, GED, BED may include the following common layers between the first and second electrodes 220, 255 other than the respective light-emitting layers 247, 246, 245:

[0107] That is, the common layers between the first electrode 220 and the second electrode 255 may include a hole injection layer 231, a hole transport layer 232, an electron transport layer 251, and the like.

[0108] Specifically, the red light emitting element RED includes a hole injection layer 231 , a hole transport layer 232 , a first hole transport assistance layer 241 , a red light emitting layer 247 , and an electron transport layer 251 between a first electrode 220 and a second electrode 255 .

[0109] The green light-emitting element GED includes a hole injection layer 231 , a hole transport layer 232 , a second hole transport assistance layer 242 , a green light-emitting layer 246 , and an electron transport layer 251 between a first electrode 220 and a second electrode 255 .

[0110] The blue light emitting element BED includes a hole injection layer 231 , a hole transport layer 232 , a blue light emitting layer 245 , and an electron transport layer 251 between a first electrode 220 and a second electrode 255 .

[0111] All layers included between the first electrode 220 and the second electrode 255 are collectively referred to as the intermediate layer, and all layers included in the intermediate layer OS may be formed including organic materials. In some cases, some layers may include a small amount of inorganic material as a dopant for electron transport, hole transport, mobility, or light emission control.

[0112] The red light emitting element RED, the green light emitting element GED, and the blue light emitting element BED have different out-coupling characteristics according to the wavelength of each emitted color by varying the vertical distance between the first electrode 220 and the second electrode 255. To achieve different vertical distances between the first and second electrodes 220 and 255, the red light emitting element RED and the green light emitting element GED may each include a first hole transport compensation layer 241 and a second hole transport compensation layer 242 with different thicknesses.

[0113] Meanwhile, in a light emitting display device according to another embodiment of the present invention, the first electrode 220 may include a reflective electrode, and the second electrode 255 may be a semi-transparent electrode or a transparent electrode.

[0114] In addition, in the light emitting display device according to another embodiment of the present invention, a capping layer 260 may be further included on the second electrode 255 to protect the light emitting elements RED, GED, and BED and improve the light emission effect. A sealing layer may be further included on the capping layer 260.

[0115] The light emitting display device of the present invention includes light emitting layers that commonly emit different colors in adjacent subpixels, and when the included light emitting elements have different vertical distances between the first and second electrodes, it can solve viewing angle variability by reducing the wavelength difference between the EL spectrum peak (electroluminescence spectrum peak) and the PL spectrum peak (light emission spectrum peak) of each light emitting layer and the corresponding light emitting element to a certain level or less. The wavelength difference between the EL spectrum peak (electroluminescence spectrum peak) and the PL spectrum peak (light emission spectrum peak) can be reduced by adjusting the materials and thicknesses of the light emitting layer material of each light emitting element and the first and second electrodes that constitute the light emitting element within the vertical distance, and in some cases, by varying the thickness of at least one of the first electrode and the second electrode.

[0116] When the difference between the EL peak and PL peak wavelengths of the red, green, and blue light-emitting elements is 2 nm or less, and the maximum value of the color viewing angle distance of the emission colors from each light-emitting element is R>G>B, the color viewing angle distance from the white color that appears when all the red, green, and blue light-emitting elements are activated is 0.010 or less. As a result, color deviation due to changes in viewing angle when the light-emitting display device displays white can be minimized or reduced, or made invisible.

[0117] In addition, the vertical distance between the first and second electrodes is different for each light-emitting element, and the structure maximizes outcoupling characteristics, preventing color viewing angle variability even in white, thereby improving image quality regardless of changes in the user's viewing angle to the screen.

[0118] In addition, the light emitting display device of the present invention can adjust the wavelength difference between the emission peak and electroluminescence peak of light by adjusting the thickness and material of the organic layer (common layer) including the light emitting layer and the light emitting element, and can manufacture a reliable light emitting display device without adding additional materials.In addition, it can reduce the environmental load, achieve low power consumption, and optimize processes, thereby achieving ESG (Environment / Social / Governance).

[0119] An organic EL display device according to an embodiment of the present invention includes a substrate including first, second, and third sub-pixels, a red light emitting element including a red light emitting layer provided in the first sub-pixel, a green light emitting element including a green light emitting layer provided in the second sub-pixel, and a blue light emitting element including a blue light emitting layer provided in the third sub-pixel, wherein a first wavelength difference between an emission peak of light from the red light emitting layer and an emission peak of the red light emitting element may be 2 nm or less, a second wavelength difference between an emission peak of light from the green light emitting layer and an emission peak of the green light emitting element may be 2 nm or less, and a third wavelength difference between an emission peak of blue light and an emission peak of the blue light emitting element may be 2 nm or less.

[0120] The white light obtained by combining the red light from the red light emitting element, the green light from the green light emitting element, and the blue light from the blue light emitting element can have a color viewing angle distance of 0.010 or less from a viewing angle of 60° or less.

[0121] Among the distances of the first color viewing angle of red light in a red light emitting element, the distances of the second color viewing angle of green light in a green light emitting element, and the distances of the third color viewing angle of blue light in a blue light emitting element, the maximum value of the distances of the first color viewing angle may be largest and the maximum value of the distances of the third color viewing angle may be smallest at a viewing angle of 60° or less.

[0122] The maximum value of the distance of the first color viewing angle occurs at a viewing angle of 45° to 60°, and the maximum value of the distance of the second color viewing angle and the maximum value of the distance of the third color viewing angle may occur at a viewing angle of 30° to 60°.

[0123] The first color viewing angle distance of red light from a red light emitting element, the second color viewing angle distance of green light from a green light emitting element, and the third color viewing angle distance of blue light from a blue light emitting element may be greater than the fourth color viewing angle distance of white light, which is the sum of red light from a red light emitting element, green light from a green light emitting element, and blue light from a blue light emitting element, at the same viewing angle.

[0124] The distance of the first color viewing angle of red light in a red light-emitting element, the distance of the second color viewing angle of green light in a green light-emitting element, and the distance of the third color viewing angle of blue light in a blue light-emitting element may be greater than the distances of the second color viewing angle and the third color viewing angle at viewing angles of 20° to 60°.

[0125] In the viewing angle range of 0° to 20°, the distance of the first color viewing angle may be smaller than the distance of the second color viewing angle and the distance of the third color viewing angle.

[0126] The red, red, green, and blue light-emitting elements may each include a first electrode and a second electrode facing each other, and the red, green, and blue light-emitting layers may be disposed between the first and second electrodes. The red, red, green, and blue light-emitting elements may also have different vertical distances between the first and second electrodes.

[0127] The red, green and blue light-emitting layers may have different thicknesses.

[0128] The device may further include a capping layer on the second electrode, the second electrode being a semi-transparent electrode, and the first electrode being a reflective electrode.

[0129] The red light-emitting layer may include multiple red light-emitting layers stacked with a common layer sandwiched between them in the first sub-pixel, the green light-emitting layer may include multiple green light-emitting layers stacked with a common layer sandwiched between them in the second sub-pixel, and the blue light-emitting layer may include multiple blue light-emitting layers stacked with a common layer sandwiched between them in the third sub-pixel.

[0130] The light-emitting device may further include a first hole transport assisting layer between an uppermost red light-emitting layer of the plurality of red light-emitting layers and the common layer, and a second hole transport assisting layer between an uppermost green light-emitting layer of the plurality of green light-emitting layers and the common layer.

[0131] The common layers may include an electron transport layer, a charge generating layer, and a hole transport layer.

[0132] The red, green, and blue light-emitting elements each include a first electrode, a hole injection layer, a hole transport layer on the hole injection layer, an electron transport layer on the hole transport layer, and a second electrode on the electron transport layer, and the red, green, and blue light-emitting layers may each be provided between the hole transport layer and the electron transport layer.

[0133] The device may further include a first hole transport assisting layer between the hole transport layer and the red light-emitting layer, and a second hole transport assisting layer between the hole transport layer and the green light-emitting layer.

[0134] The first hole transporting auxiliary layer may be configured to be thicker than the second hole transporting auxiliary layer.

[0135] On the other hand, the present invention described above is not limited to the above-mentioned embodiments and the attached drawings, and it will be apparent to those skilled in the art to which the present invention pertains that various substitutions, modifications and alterations are possible within the scope that does not deviate from the technical idea of ​​the present invention. [Explanation of symbols]

[0136] 100 boards 120 1st electrode 131 Hole injection layer 132 First hole transport layer 141 First blue light-emitting layer 142 First green light-emitting layer 143 First red light-emitting layer 151 First electron transport layer 152 n-type charge generation layer 153 p-type charge generation layer CGL charge generation layer 154 Second hole transport layer 161 Second blue light-emitting layer 162 Second green light-emitting layer 163 Second red light-emitting layer 171 Second electron transport layer 175 2nd electrode 180 capping layer RED Red light emitting element GED green light emitting element BED Blue light emitting element

Claims

1. a substrate including first, second, and third sub-pixels; thin film transistors each including a semiconductor layer, the thin film transistor being provided on the first sub-pixel, the second sub-pixel, and the third sub-pixel, the semiconductor layer including at least one of an oxide semiconductor, amorphous silicon, and crystalline silicon; an inorganic protective film provided on each of the thin film transistors of the first sub-pixel, the second sub-pixel, and the third sub-pixel; an organic protective film provided on the inorganic protective film and having a flat upper surface; a red light emitting element provided on the upper surface of the organic protective layer in the first sub-pixel, the red light emitting element including a red light emitting layer, a first hole transport assisting layer, and at least one common layer; a green light emitting element provided on the upper surface of the organic protective layer in the second sub-pixel, the green light emitting element including a green light emitting layer, a second hole transport assisting layer, and at least one common layer; a blue light emitting element provided on the upper surface of the organic protective layer in the third sub-pixel, the blue light emitting element including a blue light emitting layer and at least one common layer; a bank disposed between two adjacent light-emitting elements among the red light-emitting element, the green light-emitting element, and the blue light-emitting element; the at least one common layer of each of the red light-emitting elements, the green light-emitting elements, and the blue light-emitting elements extends over the bank, and the bank is covered by the at least one common layer; the first hole transport assistance layer is thicker than the second hole transport assistance layer, a first wavelength difference between an emission peak of the light of the red light-emitting layer and an electroluminescence peak of the red light-emitting device is 2 nm or less; a second wavelength difference between the emission peak of the light of the green light-emitting layer and the electroluminescence peak of the green light-emitting device is 2 nm or less; a third wavelength difference between the emission peak of the light of the blue light-emitting layer and the electroluminescence peak of the blue light-emitting device is 2 nm or less; The white light obtained by combining the red light from the red light-emitting element, the green light from the green light-emitting element, and the blue light from the blue light-emitting element has a color viewing angle distance of 0.010 or less from a viewing angle of 60° or less.

2. A substrate including a first subpixel, a second subpixel, and a third subpixel; thin film transistors each including a semiconductor layer, the thin film transistor being provided on the first sub-pixel, the second sub-pixel, and the third sub-pixel, the semiconductor layer including at least one of an oxide semiconductor, amorphous silicon, and crystalline silicon; an inorganic protective film provided on each of the thin film transistors of the first sub-pixel, the second sub-pixel, and the third sub-pixel; an organic protective film provided on the inorganic protective film and having a flat upper surface; a red light emitting element provided on the upper surface of the organic protective layer in the first sub-pixel, the red light emitting element including a red light emitting layer, a first hole transport assisting layer, and at least one common layer; a green light emitting element provided on the upper surface of the organic protective layer in the second sub-pixel, the green light emitting element including a green light emitting layer, a second hole transport assisting layer, and at least one common layer; a blue light emitting element provided on the upper surface of the organic protective layer in the third sub-pixel, the blue light emitting element including a blue light emitting layer and at least one common layer; a bank disposed between two adjacent light-emitting elements among the red light-emitting element, the green light-emitting element, and the blue light-emitting element; the at least one common layer of each of the red light-emitting elements, the green light-emitting elements, and the blue light-emitting elements extends over the bank, and the bank is covered by the at least one common layer; the first hole transport assistance layer is thicker than the second hole transport assistance layer, a first wavelength difference between an emission peak of the light of the red light-emitting layer and an electroluminescence peak of the red light-emitting device is 2 nm or less; a second wavelength difference between the emission peak of the light of the green light-emitting layer and the electroluminescence peak of the green light-emitting device is 2 nm or less; a third wavelength difference between the emission peak of the light of the blue light-emitting layer and the electroluminescence peak of the blue light-emitting device is 2 nm or less; Among the distance of a first color viewing angle of red light from the red light emitting element, the distance of a second color viewing angle of green light from the green light emitting element, and the distance of a third color viewing angle of blue light from the blue light emitting element, 2. The light emitting display device according to claim 1, wherein the maximum distance value of the first color viewing angle is the largest and the maximum distance value of the third color viewing angle is the smallest at a viewing angle of 60[deg.] or less.

3. the first color viewing angular distance maximum occurs at a viewing angle of 45° to 60°; The light emitting display device of claim 2 , wherein the maximum value of the distance at the second viewing angle and the maximum value of the distance at the third viewing angle occur at a viewing angle of 30° to 60°.

4. The distance of a first color viewing angle of red light from the red light emitting element, the distance of a second color viewing angle of green light from the green light emitting element, and the distance of a third color viewing angle of blue light from the blue light emitting element are 3. The light-emitting display device according to claim 1, wherein the distance of the fourth color viewing angle of white light obtained by combining red light from the red light-emitting element, green light from the green light-emitting element, and blue light from the blue light-emitting element is greater than the distance of the fourth color viewing angle of white light obtained by combining red light from the red light-emitting element, green light from the green light-emitting element, and blue light from the blue light-emitting element at the same viewing angle.

5. The distance of a first color viewing angle of red light from the red light emitting element, the distance of a second color viewing angle of green light from the green light emitting element, and the distance of a third color viewing angle of blue light from the blue light emitting element are 3. The light-emitting display device according to claim 1, wherein the distance of the first color viewing angle is greater than the distances of the second color viewing angle and the third color viewing angle in a viewing angle range of 20 degrees to 60 degrees.

6. 6. The light emitting display device according to claim 5, wherein the distance at the first color viewing angle is smaller than the distance at the second color viewing angle and the distance at the third color viewing angle in a viewing angle range of 0° to 20°.

7. the red light emitting element, the green light emitting element, and the blue light emitting element each include a first electrode and a second electrode facing each other; the red light-emitting layer, the first hole transporting assistance layer, and the at least one common layer are located between the first electrode and the second electrode of the red light-emitting element; the green light-emitting layer, the second hole transport assisting layer, and the at least one common layer are located between the first electrode and the second electrode of the green light-emitting element; the blue light-emitting layer and the at least one common layer are between the first electrode and the second electrode of the blue light-emitting element; and The light emitting display device of claim 1 , wherein the red light emitting element, the green light emitting element, and the blue light emitting element have different vertical distances between the first electrode and the second electrode.

8. The light emitting display device according to claim 7 , wherein the red light emitting layer, the green light emitting layer, and the blue light emitting layer have different thicknesses.

9. further comprising a capping layer on the second electrode; the second electrode is a semi-transparent electrode; The light emitting display device according to claim 7 , wherein the first electrode is a reflective electrode.

10. the red light-emitting layer includes a plurality of overlapping red light-emitting layers in the first sub-pixel; the green light-emitting layer includes a plurality of overlapping green light-emitting layers in the second sub-pixel; The light emitting display device of claim 7 , wherein the blue light emitting layer comprises a plurality of overlapping blue light emitting layers in the third sub-pixel.

11. the first hole transport assistance layer is located between the uppermost red light-emitting layer of the plurality of red light-emitting layers and the common layer; The light emitting display device of claim 10 , wherein the second hole transport assistance layer is located between the uppermost green light emitting layer of the plurality of green light emitting layers and the common layer.

12. The light emitting display device of claim 10 , wherein the common layer includes an electron transport layer, a charge generation layer, and a hole transport layer.

13. The at least one common layer for each of the red light emitting element, the green light emitting element, and the blue light emitting element is a hole injection layer on the first electrode; a hole transport layer on the hole injection layer; an electron transport layer on each one of the red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer; Each of the red light emitting element, the green light emitting element, and the blue light emitting element is the first electrode; a second electrode located on the electron transport layer; 3. The light-emitting display device according to claim 1, wherein the red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer are provided between the hole transport layer and the electron transport layer, respectively.

14. the first hole transport assisting layer is located between the hole transport layer and the red light-emitting layer; The light-emitting display device of claim 13 , wherein the second hole-transporting assistance layer is located between the hole-transporting layer and the green light-emitting layer.

Images