Light-emitting display device

Abstract

To provide a light-emitting display device with long life and a wide color range.SOLUTION: A light-emitting display device in an example of the present invention includes a bank 195 provided on a substrate 1000 and exposing first to fourth light-emitting parts R, G, B1, and B2, first to fourth anodes (120a to 120d) included in the first to fourth light-emitting parts R, G, B1, and B2, first light-emitting stacks RS, GS, and BS1 provided on the first to fourth anodes, a charge generation layer 170 and a second light-emitting stack BS2 provided on the first light-emitting stacks RS, GS, and BS1 in accordance with the fourth light-emitting part B2, and a cathode 170 provided on the first light-emitting stacks RS, GS, and BS1 in the first to third light-emitting parts R, G, and B1 and on the second light-emitting stack BS2 in the fourth light-emitting part B2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a display device, and more particularly to a light-emitting display device that can extend the life of a light-emitting element by modifying the structure thereof, reduce the color coordinate change characteristics due to a change in viewing angle, and widen the color gamut. [Background technology]

[0002] As we enter the information age, the field of displays that visually represent electrical information signals has rapidly developed. In response to this, a variety of display devices with excellent performance, such as thinness, light weight, and low power consumption, have been developed.

[0003] Among these, light emitting display devices that do not require a separate light source and have light emitting elements within the display panel are considered to be competitive applications for the purpose of compactness of the device and clear color display.

[0004] The light-emitting element may include an anode and a cathode facing each other as electrodes, a light-emitting layer between the anode and the cathode, and a common layer that transfers holes and electrons to the light-emitting layer.

[0005] Meanwhile, light emitting devices use luminescent materials that emit light of different wavelengths to express colors, but the efficiency and lifespan of the luminescent materials vary depending on the wavelength. Summary of the Invention [Problem to be solved by the invention]

[0006] Among light-emitting materials, light-emitting materials that emit light of short wavelengths close to ultraviolet wavelengths show opposite trends in lifespan and efficiency to those of long-wavelength dopants.

[0007] Therefore, the light-emitting display device of the present invention aims to improve both the lifetime and efficiency by changing the structure, and by applying different structures to the sub-pixels including the long-wavelength light-emitting layer and the sub-pixels including the short-wavelength light-emitting layer, it aims to improve both the lifetime and efficiency of the element using the light-emitting layer including the short-wavelength light-emitting material. [Means for solving the problem]

[0008] An emissive display device according to one embodiment of the present invention includes a bank provided on a substrate and exposing first to fourth light-emitting units, first to fourth anodes provided in the first to fourth light-emitting units, a first light-emitting stack provided on the first to fourth anodes, a charge generation layer and a second light-emitting stack provided on the first light-emitting stack corresponding to the fourth light-emitting unit, and a cathode provided on the first light-emitting stack of the first to third light-emitting units and the second light-emitting stack of the fourth light-emitting unit.

[0009] A light emitting display device according to another embodiment of the present invention includes: a bank provided on a substrate and exposing first to fourth light emitting units; first to fourth anodes provided on the first to fourth light emitting units, respectively; a first light emitting layer on the first anode, a second light emitting layer on the second anode, and a third light emitting layer on the third anode and the fourth anode; a charge generation layer and a fourth light emitting layer overlapping the fourth light emitting unit without overlapping the third light emitting unit and provided in this order on the third light emitting layer; and a cathode on the first light emitting layer, the second light emitting layer, the third light emitting layer, and the fourth light emitting layer on the first to third light emitting units and the fourth light emitting layer.

[0010] The light emitting display device of the present invention has the following effects.

[0011] In the light emitting display device of the present invention, the blue light emitting unit is divided into a single-stack blue light emitting unit and a multi-stack blue light emitting unit, and the single-stack blue light emitting unit and the multi-stack blue light emitting unit each include a blue light emitting layer containing a fluorescent dopant, and the multi-stack blue light emitting unit optionally includes a blue light emitting layer containing a phosphorescent dopant. In this case, the blue light emitting layer containing the fluorescent dopant can enhance blue color purity, and the multi-stack blue light emitting unit containing the phosphorescent dopant can increase efficiency.

[0012] Furthermore, by dualizing the structure into a single stack structure including a blue light-emitting layer having a fluorescent dopant and a multiple stack structure in which a blue light-emitting layer including a fluorescent dopant and a blue light-emitting layer including a phosphorescent dopant are superimposed, and adjusting the area ratio of the blue light-emitting portions of the single stack structure and the multiple stack structure, it is possible to optimize the life characteristics regardless of the specific blue light-emitting portion.

[0013] In addition, since the structure is divided into a single stack structure including a blue light-emitting layer having a fluorescent dopant and a multiple stack structure in which a blue light-emitting layer having a fluorescent dopant and a blue light-emitting layer having a phosphorescent dopant are overlapped, color deviation due to a change in viewing angle can be reduced compared to when only a single stack structure or only a multiple stack structure is used, or when a blue light-emitting layer having a fluorescent dopant and a blue light-emitting layer having a phosphorescent dopant are overlapped with all blue light-emitting layers, and thus user perception of a change in viewing angle can be prevented or reduced.

[0014] Furthermore, since the dual structure has a common stack, the process for forming the single stack structure and the multi-stack structure is simplified, which has the advantage of reducing the process time, and therefore has the advantage of being environmentally friendly. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a plan view illustrating a light emitting display device according to an embodiment of the present invention; [Figure 2]1 is a schematic cross-sectional view of a light emitting display device according to an embodiment of the present invention; [Figure 3] 1 is a plan view showing a light emitting display device according to a first embodiment of the present invention; [Figure 4] FIG. 2 is a cross-sectional view taken along line I-I in FIG. [Figure 5] 2 is a cross-sectional view taken along line II-II in FIG. 1 according to one embodiment of the present invention. [Figure 6] FIG. 10 is a plan view of a light emitting display device according to a second embodiment of the present invention. [Figure 7] 10 is a cross-sectional view of a light emitting display device according to a second embodiment of the present invention. [Figure 8] 1 is a cross-sectional view showing a light emitting display device according to first and second experimental examples of the present invention. [Figure 9] 1 is a graph showing a change in luminance depending on the viewing angle of the light emitting display devices according to first to third experimental examples of the present invention. [Figure 10a] 10 is a graph showing changes in color coordinates depending on changes in viewing angle of light emitting display devices according to second and third experimental examples of the present invention. [Figure 10b] 10 is a graph showing changes in color coordinates depending on changes in viewing angle of light emitting display devices according to second and third experimental examples of the present invention. [Figure 11] 1 is a graph showing the emission spectra of first to eighth experimental examples. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Throughout the specification, the same reference numerals refer to substantially identical components. 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, that detailed description will be omitted. Furthermore, the names of components used in the following description have been selected in consideration of ease of specification writing and may differ from the names of parts in an actual product.

[0017] 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 those shown in the drawings. The same drawing symbols refer to the same elements throughout this specification. Furthermore, in describing the present invention, if it is determined that a detailed description of related prior art may unnecessarily obscure the gist of the present invention, such a detailed description will be omitted. When using terms such as "comprise," "have," and "be," other parts may be added unless "only" is used. When an element is expressed in the singular, it also includes the plural unless otherwise explicitly stated.

[0018] When interpreting elements included in various embodiments of the present invention, unless otherwise expressly stated, they should be interpreted as including a margin of error.

[0019] In describing various embodiments of the present invention, when describing the positional relationship of two parts, for example, by using "above," "on top of," "below," "next to," etc., one or more other parts may be located between the two parts, unless "immediately" or "directly" is used.

[0020] In describing various embodiments of the present invention, when describing a temporal relationship, for example, when describing a temporal precedence relationship using terms such as "after," "following," "next to," or "before," non-consecutive cases may be included unless "immediately" or "directly" is used.

[0021] In describing various embodiments of the present invention, terms such as "first," "second," etc. may be used to describe various components, but such terms are only used to distinguish between identical or similar components. Therefore, in this specification, a component modified by "first" may be the same as a component modified by "second" within the technical spirit of the present invention, unless otherwise specified.

[0022] The features of the various embodiments of the present invention may be partially or fully combined or combined with each other, various technical connections and operations may be possible, and the various embodiments may be implemented independently of each other or may be implemented together in a linked relationship.

[0023] As used herein, "doped" means that a material that occupies the majority of a layer by weight is doped with less than 30% by weight of a material that has different physical properties from the material that occupies the majority of the weight (for example, N-type and P-type, or organic and inorganic materials). Alternatively, a "doped" layer refers to a layer in which the host material and dopant material of the layer can be distinguished based on their weight ratio. "Undoped" refers to all cases other than those corresponding to "doped." For example, a layer composed of a single material or a mixture of materials with identical or similar properties is considered an "undoped" layer. For example, if at least one material constituting a layer is P-type and all materials constituting the layer are not N-type, the layer is considered an "undoped" layer. For example, if at least one material constituting a layer is organic and all materials constituting the layer are not inorganic, the 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 at least one other is P-type, the layer will be considered "doped" if the weight ratio of the N-type material is less than 30% or the weight ratio of the P-type material is less than 30%.

[0024] Meanwhile, in this specification, the EL (electroluminescence) spectrum is calculated as the product of (1) the PL (photoluminescence) spectrum, which reflects the inherent properties of the luminescent materials, such as the dopant material and the host material, contained in the organic luminescent layer, and (2) the outcoupling emittance spectrum curve, which is determined by the structure and optical properties of the organic light-emitting device, including the thickness of the organic layers, such as the electron transport layer.

[0025] Hereinafter, a light emitting device and a light emitting display device including the same according to the present invention will be described with reference to the accompanying drawings.

[0026] Fig. 1 is a plan view showing a light emitting display device according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view of a light emitting display device according to an embodiment of the present invention. Fig. 3 is a plan view showing a light emitting display device according to a first embodiment of the present invention. Fig. 4 is a cross-sectional view taken along line I-I in Fig. 1. Fig. 5 is a cross-sectional view taken along line II-II in Fig. 1 according to an embodiment of the present invention.

[0027] As shown in Figures 1 to 5, an emissive display device according to an embodiment of the present invention includes a bank 195 provided on a substrate 1000 and exposing first to fourth light-emitting units R, G, B1, and B2, first to third anodes 120a, 120b, and 120c provided in the first to fourth light-emitting units R, G, B1, and B2, first light-emitting stacks RS, GS, and BS1 provided on the first to third anodes 120a, 120b, and 120c, a charge generation layer 170 and a second light-emitting stack BS2 provided on the first light-emitting stack BS1 of the fourth light-emitting unit B2, and a cathode 190 provided on the first light-emitting stacks RS, GS, and BS1 of the first to third light-emitting units R, G, and B1 and the second light-emitting stack BS2 of the fourth light-emitting unit B2.

[0028] In the light emitting display device of the present invention, the first to fourth light emitting portions R, G, B1, and B2 form a set to form a pixel P, and the pixels P are repeatedly arranged on the substrate 1000.

[0029] In the light-emitting display device of the present invention, the third light-emitting section B1 and the fourth light-emitting section B2 are light-emitting sections that emit light of the same color, but differ in that they have different stack structures, i.e., the fourth light-emitting section B2 further includes a charge generation layer 170 and a second light-emitting stack BS2 compared to the third light-emitting section B1.

[0030] The first to third light emitting units R, G, and B1 are merely examples and may be divided into a red light emitting unit, a green light emitting unit, and a blue light emitting unit, respectively. The first to third light emitting units may have a combination of light emitting units of other colors that can be combined to produce white color in addition to the aforementioned red, green, and blue.

[0031] In the light-emitting display device of the present invention, the third light-emitting unit B1 and the fourth light-emitting unit B2, which emit light of the same color but have different numbers of light-emitting stack structures, refer to light-emitting units of a color that have lower efficiency than light-emitting units of other colors provided in the light-emitting display device with the same stack structure. Therefore, if the efficiency of the red light-emitting unit or the green light-emitting unit is lower than that of the blue light-emitting unit with the same stack structure, the light-emitting display device may have a dual stack structure in which the blue light-emitting unit and the light-emitting units of other colors are combined.

[0032] The first to third light emitting units R, G, and B1 include a red light emitting layer 151, a green light emitting layer 152, and a first blue light emitting layer 153 in their first light emitting stacks RS, GS, and BS1, respectively.

[0033] The fourth light-emitting unit B2 includes a first blue light-emitting layer 153 integrated with the first blue light-emitting layer 153 in the first light-emitting stack BS1, and a second blue light-emitting layer 180 in the second light-emitting stack BS2.

[0034] As shown in FIG. 4, the third light-emitting portion B1 and the fourth light-emitting portion B2 may be separated by a bank 195.

[0035] In the light emitting display device according to an embodiment of the present invention, the third light emitting unit B1 is a light emitting unit that emits light with the shortest wavelength. The reason why the light emitting unit that emits light with short wavelengths is divided into the third light emitting unit B1 and the fourth light emitting unit B2 in the light emitting display device of the present invention is as follows.

[0036] Therefore, in a structure having light-emitting layers divided into a plurality of wavelengths on a plane, when the same stack is used, the blue light-emitting unit has lower efficiency than the green and red light-emitting units. In an emissive display device according to one embodiment of the present invention, the blue light-emitting unit includes a third light-emitting unit B1 having a single light-emitting stack and a fourth light-emitting unit B2 having multiple light-emitting stacks, thereby increasing the blue efficiency of the fourth light-emitting unit B2 and improving the blue light-emitting efficiency of the entire emissive display device on average.

[0037] Furthermore, relatively short-wavelength light-emitting materials have lower visibility and lower efficiency than long-wavelength light-emitting materials with the same structure. Furthermore, it is increasingly necessary to widen the color gamut in order to display colors closer to natural colors, and there is a strong demand for a wider color gamut in the blue region than in the saturated green and red regions. For example, when the light-emitting display device of the present invention includes a red light-emitting portion, a green light-emitting portion, and a blue light-emitting portion, it aims to widen the blue region, which is the region in which blue is expressed at the shortest wavelength.

[0038] Here, the third light-emitting unit B1 and the fourth light-emitting unit B2 have the same first blue light-emitting layer 153 in common, and the first blue light-emitting layer 153 provided in common to the third light-emitting unit B1 and the fourth light-emitting unit B2 contains a fluorescent dopant with excellent life characteristics, and optionally, the second blue light-emitting layer 180 provided in the fourth light-emitting unit B2 contains a non-fluorescent dopant with excellent efficiency characteristics.

[0039] The non-fluorescent dopant may include a phosphorescent dopant or a thermally activated delayed fluorescent (TADF) dopant. Non-fluorescent dopants have superior external quantum efficiency to fluorescent dopants. However, non-fluorescent dopants can have a reduced lifetime due to quenching characteristics within the emitting layer over time. Therefore, in the light-emitting display device of the present invention, the third emitting unit B1 uses a single first emitting stack BS1 and includes a first blue emitting layer 153 having only a fluorescent dopant. The fourth emitting unit B2 includes a first emitting stack BS1 including the first blue emitting layer 153 having a fluorescent dopant and a second emitting stack BS2 including a second blue emitting layer 180 having a phosphorescent dopant or a delayed fluorescent dopant. This prevents the reduced lifetime and pure color efficiency that occur in a structure using only a non-fluorescent dopant.

[0040] The third anode 120c of the third light-emitting unit B1 and the third anode 120c of the fourth light-emitting unit B2 may be integral with each other and connected laterally. In some cases, the third anode 120c of the third light-emitting unit B1 and the third anode 120c of the fourth light-emitting unit B2 may be spaced apart from each other.

[0041] A bank 195 is provided between the third anode 121c and the fourth anode 121d, dividing the third and fourth light-emitting units B1 and B2 into different regions, and blue light is emitted from different stacks, thereby improving efficiency and lifetime. Furthermore, the third and fourth light-emitting units B1 and B2, which emit the same color, have a dualized stack structure, which ultimately allows the half-widths of the lights emitted from the third and fourth light-emitting units B1 and B2 to differ, thereby reducing color coordinate deviations due to changes in viewing angle.

[0042] In the light emitting display device of the present invention, the third light emitting unit B1 and the fourth light emitting unit B2 not only represent the average efficiency of the first blue light emitting layer 153 and the second blue light emitting layer 180 when expressing blue, but also have a low blue coordinate that allows for expression of pure blue, thereby increasing the overlapping area of ​​the desired color gamut range and significantly improving the expression of pure blue colors. Recently, the most commonly used reference color gamuts include BT2020 and DCI-P3. BT2020 is a next-generation standard color gamut first approved by the International Telecommunication Union (ITU) in June 2014. It is a color gamut designed to support the UHDTV environment, supports a brightness expression of 10,000 nits, and takes HDR mastering into consideration.

[0043] DCI-P3 is a color gamut defined by the Digital Cinema Initiatives for use in the US film industry as the color gamut for digital projectors. It can express a color gamut 25% wider than sRGB, with particularly wide coverage in the red region. The light-emitting display device of the present invention can achieve an overlap of 99% or more with the DCI-P3 color gamut by expanding blue efficiency and pure color gamut.

[0044] Specific effects will be explained for each experimental example with reference to tables.

[0045] The first light-emitting stack RS, GS, BS1 may include the first to third anodes 120a, 120b, 120c, and a first common layer 130 located between the red light-emitting layer 151, the green light-emitting layer 152, and the first blue light-emitting layer 153.

[0046] Here, the first common layer 130 may include a hole injection layer HIL and a hole transport layer HTL. The hole injection layer HIL and the hole transport layer HTL may be formed as a single layer in some cases. Furthermore, at least one of the hole injection layer HIL and the hole transport layer HTL may include multiple layers as necessary. Furthermore, the first common layer 130 may be formed as a structure in which a first material and a second material are alternately stacked, thereby performing hole injection and hole transport together.

[0047] The first light-emitting stack RS, GS, BS1 may further include a second common layer 160 on the first red light-emitting layer 151, the green light-emitting layer 152, and the first blue light-emitting layer 153.

[0048] The second common layer 160 may include a hole-blocking layer HBL and an electron-transporting layer ETL. The hole-blocking layer confines holes within the red light-emitting layer 151, the green light-emitting layer 152, and the first blue light-emitting layer 153, and has a lower HOMO level than the electron-transporting layer ETL to prevent holes from escaping toward the electron-transporting layer ETL.

[0049] In some cases, the second common layer 160 may omit either the hole blocking layer or the electron transport layer, or may include a plurality of layers.

[0050] In the light emitting display device according to an embodiment of the present invention, the first to third light emitting units R, G, and B1 each have one first light emitting stack RS, GS, and BS1, while the fourth light emitting unit B2 has both the first and second light emitting stacks BS1 and BS2. The fourth light emitting unit B2 also has a charge generation layer 170 between the first light emitting stack BS1 and the second light emitting stack BS2.

[0051] The first to third light emitting units R, G, and B1 having the first light emitting stack BS1 may have different optimal resonance distances. Therefore, in order to adjust the resonance distance for each emission color, hole transport assisting layers 123 and 125 may be further provided between the first common layer 130 and the light emitting layers 151 and 152 of the first light emitting stack.

[0052] As shown in FIG. 2, the first light-emitting stack BS1 may further include an electron blocking layer 140 common to the first to fourth light-emitting portions R, G, B1, and B2, which confines electrons in the light-emitting layers 151, 152, and 153 and prevents electrons from escaping toward the first to third anodes 120a, 120b, and 120c. The electron blocking layer 140 is optional and may be omitted in some cases. Alternatively, the electron blocking layer 140 may have different thicknesses and components required for the red light-emitting layer 151, the green light-emitting layer 152, and the first blue light-emitting layer 153. In this case, the electron blocking layer 140 may be selectively provided only in specific light-emitting portions, or the thickness of the electron blocking layer 140 provided in the specific light-emitting portion may be increased.

[0053] The hole transport auxiliary layers 123 and 125 may be provided to compensate for the resonance distance of each emission color, and may be provided between the first common layer and the electron blocking layer, as shown in FIG. 2, or may be provided between the electron blocking layer and the light-emitting layer of the first light-emitting stack.

[0054] By selectively applying the hole transport assistance layers 123, 125, the thicknesses of the first light-emitting stacks RS and GS of the first light-emitting portion R and the second light-emitting portion G may be thicker than the thicknesses of the first light-emitting stacks BS1 of the third light-emitting portion B1 and the fourth light-emitting portion B2. Also, the thickness of the first light-emitting stack RS of the first light-emitting portion R may be thicker than the thickness of the first light-emitting stack GS of the second light-emitting portion G. The thickness of the first light-emitting stack RS of the first light-emitting portion R may be the thickest among the first to fourth light-emitting portions R, G, B1, and B2.

[0055] In addition to the second blue light-emitting layer 180, the second light-emitting stack BS2 may further include a hole transport layer 175 below the second blue light-emitting layer 180 and an electron transport layer 185 above the second blue light-emitting layer 180.

[0056] Each of the hole transport layer 175 and the electron transport layer 185 may optionally be multilayered.

[0057] The charge generation layer 170 may be formed by stacking an n-type charge generation layer and a p-type charge generation layer. In some cases, the hole transport layer may be omitted from the second light-emitting stack BS2, and the p-type charge generation layer in the charge generation layer 170 may function as the hole transport layer.

[0058] A cathode 190 is provided on the second common layer 160 of the first to third light-emitting units R, G, and B1 and on the electron transport layer 185 of the second light-emitting stack BS2 of the fourth light-emitting unit B2.

[0059] The cathode 190 may be composed of multiple layers. When the cathode 190 is composed of multiple layers, the multiple layer structure may include a metal layer or an inorganic compound layer having the function of an electron injection layer on the surface where the second common layer 160 and the electron transport layer 185 are in contact.

[0060] A capping layer 200 may further be included on the cathode 190 .

[0061] The capping layer 200 may include a first capping layer 210 and a second capping layer 220 made of different materials. The first capping layer 210 and the second capping layer 220 may be transparent insulating films having different refractive indices. Alternatively, the first capping layer 210 and the second capping layer 220 may be insulating films having different physical properties, such as inorganic and organic.

[0062] The capping layer 200 covers the cathode 190, protecting the light-emitting element consisting of the anodes 120a-120c and the cathode 190, the first light-emitting stack RS, GS, and BS1 between the anodes 120a-120c and the cathode 190, the charge generation layer 170, and the second light-emitting stack BS2, and serves to enhance the light emission efficiency of the light-emitting element.

[0063] In the fourth light-emitting unit B2, one of the first blue light-emitting layer 153 and the second blue light-emitting layer 180 contains a fluorescent dopant, and the other contains a phosphorescent dopant, thereby improving color purity and expanding the color gamut.

[0064] In particular, in the light emitting display device according to one embodiment of the present invention, the first blue light emitting layer 153 provided in common to the third and fourth light emitting units B1 and B2 of the third light emitting unit B1 and the fourth light emitting unit B2 that emit the same color contains a fluorescent dopant, and the second blue light emitting layer 180 provided only in a part of the fourth light emitting unit B2 contains a phosphorescent dopant. This can improve efficiency and lifespan compared to a structure including a single stack structure, and can significantly reduce changes in color deviation due to an expansion of the color gamut and changes in viewing angle.

[0065] In addition, the light emitting display device according to one embodiment of the present invention can significantly reduce changes in color deviation due to changes in viewing angle, compared to a blue light emitting layer structure that applies a multiple stack structure to a single light emitting unit and uses a fluorescent dopant and a phosphorescent dopant in different stacks, which has a large change in color coordinate characteristics due to changes in viewing angle.

[0066] The light emitting display device according to the first embodiment of the present invention is characterized in that it includes first and second anodes 120a, 120b provided in the first light emitting unit R and the second light emitting unit G, respectively, and a third anode 120c provided in common to the third light emitting unit B1 and the fourth light emitting unit B2.

[0067] The stacked structure of the first to fourth light emitting portions R, G, B1, and B2 is the same as or similar to that described above with reference to FIG.

[0068] That is, as shown in Figures 3 and 4, the first light-emitting unit R has a first common layer 130 of a hole injection functional layer on the first anode 120a, a hole transport or electron blocking functional layer 140 on the first common layer 130, a red light-emitting layer 151 on the electron blocking functional layer 140, a second common layer 160 of an electron transport functional layer on the red light-emitting layer 151, and a cathode 190 on the second common layer 160, in that order.

[0069] As shown in Figures 3 and 5, the second light-emitting section G has a first common layer 130 of a hole injection functional layer on the second anode 120b, a hole transport or electron blocking functional layer 140 on the first common layer 130, a green light-emitting layer 152 on the electron blocking functional layer 140, a second common layer 160 of an electron transport functional layer on the green light-emitting layer 152, and a cathode 190 on the second common layer 160, in that order.

[0070] As shown in Figures 3 and 4, the third light-emitting unit B1 has a first common layer 130 of a hole injection functional layer on the third anode 120c, a hole transport or electron blocking functional layer 140 on the first common layer 130, a first blue light-emitting layer 153 on the electron blocking functional layer 140, a second common layer 160 of an electron transport functional layer on the first blue light-emitting layer 153, and a cathode 190 on the second common layer 160, in that order.

[0071] As shown in Figures 3 and 5, the fourth light-emitting section B2 further includes a charge generation layer 170 and a second light-emitting stack of a hole transport layer 175, a second blue light-emitting layer 180, and an electron transport layer 185, compared to the third light-emitting section B1.

[0072] Red light-emitting layer 151 is a light-emitting layer having an emission peak at a wavelength of 600 nm to 650 nm.

[0073] The green light-emitting layer 152 is a light-emitting layer having an emission peak in the wavelength range of 500 nm to 590 nm.

[0074] The first blue light-emitting layer 153 and the second blue light-emitting layer 180 are light-emitting layers having an emission peak at 420 nm to 490 nm. The first blue light-emitting layer 153 may contain a fluorescent dopant, and the second blue light-emitting layer 180 may contain a non-fluorescent dopant, such as a phosphorescent dopant or a delayed fluorescent dopant.

[0075] In some cases, charge generation layer 170 can be an n-type charge generation layer and hole transport layer 175 can be integrated with a p-type charge generation layer.

[0076] A cathode 190 and a capping layer 200 are formed in this order on the second common layer 160 of the first to third light emitting sections R, G, and B1 and on the electron transport layer 185 on the fourth light emitting section B2.

[0077] Here, the lower surface of the cathode 190 contacts the second common layer 160 in the first to third light-emitting sections R, G, and B1, and contacts the electron transport layer 185 in the fourth light-emitting section B2, and the lower surface of the cathode 190 can contact the second common layer 160 and the electron transport layer 185, which have electron transport function, in common to the first to fourth light-emitting sections R, G, B1, and B2.

[0078] The first anode 120a, the second anode 120b and the third anode 120c are connected to thin film transistors TFT provided on the substrate 100, and a driving current is applied thereto.

[0079] Meanwhile, in the light emitting display device of the present invention, the substrate 1000 on which the first to third anodes 120a, 120b, and 120c are formed is called a thin film transistor array substrate including the base material 100, the thin film transistor TFT, and the protective film 108 that protects the thin film transistor TFT.

[0080] Here, the substrate 100 includes at least one of plastic, glass, and a metal plate. The substrate 100 can have flexible or rigid properties depending on the material or components thereof.

[0081] The protective film 108 may be a multi-layer film in some cases, and the upper film has a planarizing function, and the first to fourth light emitting portions R, G, B1, and B2 may be defined on the upper surface of the flat protective film 108.

[0082] For example, the thin film transistor TFT includes a gate electrode 102, a semiconductor layer 104 overlapping the gate electrode 102, and a first electrode 106a and a second electrode 106b connected to both sides of the semiconductor layer 104. A gate insulating film 101 is interposed between the gate electrode 102 and the semiconductor layer 104. A channel protection layer 105 is provided on the channel of the semiconductor layer 104, thereby preventing direct connection between the channel portion of the semiconductor layer 104 and the first electrode 106a and the second electrode 106b and maintaining intrinsic characteristics.

[0083] Either the first electrode 106a or the second electrode 106b of the thin film transistor TFT can be a source electrode, and the other can be a drain electrode. Either the first electrode 106a or the second electrode 106b can be connected to a respective anode 120a, 120b, or 120c.

[0084] The bank 195 is configured to expose the light-emitting portions R, G, B1, and B2 of the first to third anodes 120a, 120b, and 120c. The bank 195 may be provided to overlap the edges of the first and second anodes 120a and 120b. In the light-emitting display device according to the first embodiment of the present invention, as shown in FIGS. 4 and 5, the third anode 120c is integrally provided with the third and fourth light-emitting portions B1 and B2. The bank 195 may be provided not only at the edges of the third anode 120c but also between the third and fourth light-emitting portions B1 and B2. The third and fourth light-emitting portions B1 and B2 each include a single third anode 120c, and the third anode 120c is connected to the same thin-film transistor TFT to transmit a driving current to the third light-emitting portion B1 and the fourth light-emitting portion B2.

[0085] Here, a first common layer 130 of a hole injection functional layer is provided on the third anode 120c, a hole transport or electron blocking functional layer 140 is provided on the first common layer 130, a first blue light-emitting layer 153 is provided on the electron blocking functional layer 140, a second common layer 160 of an electron transport functional layer is provided on the first blue light-emitting layer 153, and a cathode 190 is provided on the second common layer 160, in this order.

[0086] Between the third light-emitting section B1 and the fourth light-emitting section B2, the bottom surface of the electron transport layer 185 in the second light-emitting stack BS2 of the fourth light-emitting section B2 is formed wider than the second blue light-emitting layer 180 and is in contact with the second common layer 160 of the first light-emitting stack BS1. Therefore, by providing different stacked structures in the third light-emitting section B1 and the fourth light-emitting section B2, the area having a step is covered with the electron transport layer 185, and outside the step, the electron transport layer 185 is in contact with the second common layer 160 common to the first to fourth light-emitting sections R, G, B1, and B2, and the bottom surface of the cathode 190 is in contact with the electron transport layer 185 and second common layer 160, which have the same electron transport functionality, in the first to fourth light-emitting sections R, G, B1, and B2.

[0087] Meanwhile, on the capping layer 200, a sealing layer 300 is provided to protect the light-emitting elements consisting of the first to third anodes 120a, 120b, 120c and cathode 190 provided in the first to fourth light-emitting portions R, G, B1, B2, and the first light-emitting stacks RS, GS, BS1 and second light-emitting stack BS2 between the first to third anodes 120a, 120b, 120c and the cathode 190.

[0088] The encapsulation layer 300 may include at least one inorganic encapsulation layer and at least one organic encapsulation layer, and the inorganic encapsulation layer and the organic encapsulation layer of the encapsulation layer 300 may be alternately formed.

[0089] 4 and 5, the light emitting display device according to an embodiment of the present invention includes a first anode 120a provided in a region including at least the first light emitting portion R, a second anode 120b provided in a region including at least the second light emitting portion G, and a third anode 120c provided across the third and fourth light emitting portions B1 and B2. The first anode 120a, the second anode 120b, and the third anode 120c are separated from each other. The third anode 120c is provided in common to the third light emitting portion B1 and the fourth light emitting portion B2, which are separated by a bank 195, and can be driven in response to the same signal. The light emitting display device according to an embodiment of the present invention also includes a first light emitting layer 151 on the first anode 120a, a second light emitting layer 152 on the second anode 120b, and a third light emitting layer 153 on the third anode 120c. The third light-emitting layer 153 overlaps both the third light-emitting portion B1 and the fourth light-emitting portion B2 and is provided on the third anode 120c.

[0090] In addition, the light emitting display device does not overlap with the third light emitting unit B1 but overlaps with the fourth light emitting unit B2, and a charge generation layer 170 and a fourth light emitting layer 180 are provided in order on the third light emitting layer 153, and a cathode 190 and a capping layer 200 are provided in common on the first to fourth light emitting units R, G, B1, and B2.

[0091] Here, the cathode 190 is provided on the first light-emitting layer 151, the second light-emitting layer 152 and the third light-emitting layer 153 which are provided in a single stack on the first to third light-emitting sections R, G and B1, and on the fourth light-emitting layer 180 on the fourth light-emitting section B2 which consists of multiple stacks.

[0092] The bank 195 is provided on the substrate 1000, and exposes the anodes 120a, 120b, and 120c of the first to fourth light-emitting portions R, G, B1, and B2.

[0093] In the first to third light emitting units R, G, and B1, the lower surface of the cathode 190 may be in direct contact with the second common layer 160, which functions as an electron transport layer, and in the fourth light emitting unit B2, the lower surface of the cathode 190 may be in direct contact with the electron transport layer 185, which has an electron transport function.

[0094] The difference is that the third light-emitting layer 153 provided in common to the third light-emitting unit B1 and the fourth light-emitting unit B2 contains a fluorescent dopant, while the fourth light-emitting layer 180 selectively provided in the fourth light-emitting unit B2 contains a non-fluorescent dopant.

[0095] Here, the non-fluorescent dopant can be a phosphorescent dopant or a delayed fluorescent dopant.

[0096] A first common layer 130 including a hole injection layer with a hole injection function and an electron injection layer with an electron transport function stacked thereon may be provided between the first to third anodes 120a, 120b, and 120c and the first to third light emitting layers 151, 152, and 153. An electron blocking layer 140 for confining holes in the first to third light emitting layers 151, 152, and 153 may be provided on the first common layer 130. A second common layer 160 with an electron transport function is provided between the first to third light emitting layers 151, 152, and 153 and the cathode 190.

[0097] The fourth light emitting unit B2 may optionally further include an additional stack, and may further include an electron transport layer 185 between the fourth light emitting layer 180 and the cathode 190. In addition, the fourth light emitting unit B2 may optionally include a hole transport layer 175 having a hole transport function between the charge generation layer 170 and the fourth light emitting layer 180.

[0098] The charge generation layer 170 may be divided into an n-type charge generation layer and a p-type charge generation layer. In this case, the n-type charge generation layer may function to generate electrons and transport the electrons to the second common layer 160 of the lower stack.

[0099] In addition, the p-type charge generation layer may generate holes and transport them to the upper stack of the fourth light emitting unit B2. In this case, the hole transport layer below the fourth light emitting layer 180 may be omitted, and the p-type charge generation layer may function as the hole transport layer of the upper stack.

[0100] First light-emitting layer 151 is a layer that emits red light having a peak wavelength in the wavelength range of 600 nm to 650 nm, and second light-emitting layer 152 can be a green or yellow-green light-emitting layer having a peak wavelength in the wavelength range of 510 nm to 590 nm.

[0101] The third light-emitting layer 153 and the fourth light-emitting layer 180 are layers that emit blue light having a peak wavelength in the range of 420 nm to 490 nm, and differ depending on whether or not they contain a fluorescent dopant.

[0102] Each of the first to fourth light-emitting layers 151, 152, 153, and 180 can include one or more hosts and one or more dopants.

[0103] FIG. 6 is a plan view of a light emitting display device according to a second embodiment of the present invention, and FIG. 7 is a cross-sectional view of the light emitting display device according to the second embodiment of the present invention.

[0104] 6 and 7, the light emitting display device according to the second embodiment of the present invention is different from the light emitting display device according to the first embodiment in that the anodes of the third light emitting unit B1 and the fourth light emitting unit B2 are formed separately. That is, the third anode 120c of the third light emitting unit B1 and the fourth anode 120d of the fourth light emitting unit B2 are separated, and the third anode 120c and the fourth anode 120d are connected to independent thin film transistors to which individual driving currents are applied.

[0105] In the light-emitting display device according to the second embodiment of the present invention, the first light-emitting stack BS1 including the first blue light-emitting layer 153 is formed in common in the third light-emitting section B1 and the fourth light-emitting section B2, and the second light-emitting stack BS2 including the second blue light-emitting layer 180 is selectively provided in the fourth light-emitting section B2.

[0106] The effects of the light emitting display device of the present invention will be explained below based on experiments.

[0107] Since the light emitting display device of the present invention has variations in the blue light emitting portion, variations in color coordinates and viewing angles will be described based on experimental examples in which the structures of the blue light emitting portions are different.

[0108] FIG. 8 is a cross-sectional view showing a light emitting display device according to first and second experimental examples of the present invention.

[0109] As shown in FIG. 8, the light emitting display device of the first experimental example and the light emitting display device of the second experimental example have a two-stack structure laminated together in the blue light emitting section.

[0110] The light-emitting display device of the first experimental example uses the same type of light-emitting dopant in each light-emitting portion of the first light-emitting stack and the second light-emitting stack. The blue light-emitting portion is configured such that the blue light-emitting layer of each of the first and second light-emitting stacks contains a blue fluorescent dopant.

[0111] The light emitting display device of the second experimental example differs from the light emitting display device of the first experimental example only in that the blue light emitting layer in the second light emitting stack of the blue light emitting unit uses a blue phosphorescent dopant.

[0112] Meanwhile, the light emitting display device of the third experimental example has the structure of the light emitting display device according to the first embodiment of the present invention described with reference to FIGS.

[0113] That is, in the light-emitting display device according to the third experimental example, the blue light-emitting section includes a third light-emitting section B1 and a fourth light-emitting section B2, the third light-emitting section B1 includes a first light-emitting stack BS1 having a first blue light-emitting layer 153 containing a fluorescent dopant, and the fourth light-emitting section B2 further includes a first light-emitting stack BS1 and a second light-emitting stack BS2 including a charge generation layer 170 and a second blue light-emitting layer 180 containing a phosphorescent dopant on the first light-emitting stack BS1.

[0114] [Table 1]

[0115] [Table 2]

[0116] Fig. 9 is a graph showing a change in luminance with respect to the viewing angle of the light emitting display devices according to the first to third experimental examples of the present invention. Fig. 10a and Fig. 10b are graphs showing a change in color coordinates with respect to the viewing angle of the light emitting display devices according to the second and third experimental examples of the present invention.

[0117] As shown in Tables 1 and 2 and FIG. 9, it can be seen that the phenomenon of brightness reduction due to the change in viewing angle is the smallest in the third experimental example according to the first embodiment of the present invention.

[0118] Furthermore, as shown in Figure 8, the light-emitting display device of the second experimental example, which has first and second light-emitting stacks in one blue light-emitting section, where the first blue light-emitting layer contains a blue fluorescent dopant and the second blue light-emitting layer contains a blue phosphorescent dopant, shows a Δuv color coordinate change of 0.0071 with a viewing angle change of 0° to 30° and a deviation of 0.0051 with a viewing angle change of 30° to 45°, as shown in Tables 1 and 2 and Figure 10a.This means that the color coordinate deviation due to the viewing angle change is large and the color difference due to the viewing angle change is easily noticeable.

[0119] 2 to 5, the light emitting display device according to the first embodiment of the present invention includes a third light emitting unit B1 having a first light emitting stack BS1 having a first blue light emitting layer 153 containing a blue fluorescent dopant, and a second light emitting stack BS2 having a second blue light emitting layer 180 containing a phosphorescent dopant stacked on the first light emitting stack BS1. Therefore, as shown in Tables 1 and 2 and FIG. 10b, the light emitting display device according to the first embodiment of the present invention exhibits a Δu'v' color coordinate change of 0.0048 with a viewing angle change of 0° to 30° and a deviation of 0.0039 with a viewing angle change of 30° to 45°, thereby reducing the color coordinate deviation due to a viewing angle change and thereby reducing the perception of color difference even when the viewing angle changes.

[0120] Meanwhile, in Figures 10a, 10b, and Table 1, JND (Just Noticeable Differences) is a numerical representation of the deviation of the color coordinate variation range due to a change in viewing angle from the viewing angle value at 0 degrees. In Figures 10a and 10b, the inner ellipse represents the JND value, and the outer ellipse represents the JND value. In Table 1, the JND values ​​of the light emitting display devices according to the first to third experimental examples at each viewing angle represent the JND values ​​at each viewing angle of the corresponding experimental example, and a smaller JND value indicates a smaller deviation from the color coordinate at a viewing angle of 0 degrees.

[0121] As shown in Figure 10a and Table 1, the light-emitting display device according to the second experimental example (Ex2) has a JND value of 5.2, particularly at the mainly observed angle of 0° to 30°, and as shown in Figure 10b and Table 1, it can be seen that the light-emitting display device according to the third experimental example (Ex3) has a JND value of 1.8, which shows a significant color deviation.

[0122] Below, we observed the By characteristics, color gamut, and emission spectrum of the fourth experimental example (Ex4), which contains a phosphorescent dopant in common in the blue light-emitting layer in the structure in which two light-emitting stacks are stacked as shown in Figure 8, along with the first to third experimental examples (Ex1, Ex2, Ex3) described above. Here, in the third experimental example (Ex3), the area ratio of the third light-emitting section B1 with a single blue light-emitting stack structure to the fourth light-emitting section B2 with a multiple blue stack structure was set to 1:1.

[0123] The By characteristics and color gamuts of the fifth to eighth experimental examples (Ex5a, Ex5b, Ex5c, and Ex5d), which are variations of the third experimental example (Ex3) and in which the area ratio of the third light-emitting section B1 with a single blue light-emitting stack structure to the fourth light-emitting section B2 with a multiple blue stack structure was changed to 3:1, 2:1, 1:2, and 1:3, respectively, were observed.

[0124] FIG. 11 is a graph showing the emission spectra of the first to eighth experimental examples.

[0125] [Table 3]

[0126] As shown in Table 3 and Figure 11, in the blue light-emitting region, as in Experimental Example 4 (Ex4), the By value increases and color purity decreases as the amount of phosphorescent dopant used increases. In particular, as shown in Figure 11, it can be seen that the blue emission spectrum shifts to the right as the amount of phosphorescent dopant used increases.

[0127] On the other hand, in the third experimental example (Ex3) and the fifth to eighth experimental examples (Ex5a, Ex5b, Ex5c, and Ex5d), in which the third light-emitting section B1 having a single blue light-emitting stack structure and the fourth light-emitting section B2 having a multiple blue light-emitting stack structure are combined, the superimposed color gamut in DCI-P3 is 100%, which confirms that the color gamut meets the requirements in DCI-P3.

[0128] Table 4 below compares the life characteristics of the third experimental example (Ex3), the fifth experimental example (Ex5a), and the eighth experimental example (Ex5d) according to the area ratio between the third light-emitting portion B1 and the fourth light-emitting portion B2.

[0129] As in the third experimental example (Ex3), the life characteristics of the third light-emitting section B1 and the fourth light-emitting section B2 were determined to be 1.0 and 1.0, respectively, when the area ratio of the third light-emitting section B1 to the fourth light-emitting section B2 was 1:1.

[0130] In the fifth experimental example (Ex5a), when the area of ​​the third light-emitting section B1 is three times the area of ​​the fourth light-emitting section B2, if the lifespan of the third light-emitting section B1 is 1.0, the lifespan of the fourth light-emitting section B2 tends to be extended by 4.1 times when the same driving current is supplied to an area reduced to 1 / 3 of the area of ​​the third light-emitting section B1.

[0131] On the other hand, in the eighth experimental example (Ex5d), when the area of ​​the fourth light-emitting section B2 is three times that of the third light-emitting section B1, if the lifetime of the third light-emitting section B1 is 1.0, the fourth light-emitting section B2, which includes two blue light-emitting stacks, tends to have a lifetime reduced to 0.1 times as the same driving current is supplied to an area three times that of the third light-emitting section B1.

[0132] 11, in terms of color purity and color gamut, simply including the third light-emitting unit B1 and the fourth light-emitting unit B2 together is effective, but in terms of drive and lifespan, as shown in Table 4, if a reduction in lifespan occurs in a specific light-emitting unit, the light-emitting display device will depend on the lifespan characteristics of the light-emitting unit in which the reduction in lifespan occurs, so it is preferable that light-emitting units emitting the same color have similar or identical lifespan characteristics. In this regard, if the third light-emitting unit B1 and the fourth light-emitting unit B2 have similar or identical areas, it can be expected that a similar lifespan improvement effect can be achieved in the entire light-emitting display device, regardless of the lifespan characteristics of a specific light-emitting unit.

[0133] [Table 4]

[0134] However, the light emitting display device of the present invention is not limited to the third and fourth light emitting units having the same or similar area ratio. The above experiments have confirmed that the color purity and color gamut can be improved simply by providing the third and fourth light emitting units in common, and the area ratio of the third and fourth light emitting units in the light emitting display device of the present invention may be in the range of 1:10 to 10:1.

[0135] In the light emitting display device of the present invention, the blue light emitting unit is divided into a single-stack blue light emitting unit and a multi-stack blue light emitting unit, and the single-stack blue light emitting unit and the multi-stack blue light emitting unit each include a blue light emitting layer containing a fluorescent dopant, and the multi-stack blue light emitting unit optionally includes a blue light emitting layer containing a phosphorescent dopant. In this case, the blue light emitting layer containing the fluorescent dopant can enhance blue color purity, and the multi-stack blue light emitting unit containing the phosphorescent dopant can increase efficiency.

[0136] Furthermore, by dualizing the structure into a single stack structure including a blue light-emitting layer having a fluorescent dopant and a multiple stack structure in which a blue light-emitting layer including a fluorescent dopant and a blue light-emitting layer including a phosphorescent dopant are superimposed, and adjusting the area ratio of the blue light-emitting portions of the single stack structure and the multiple stack structure, it is possible to optimize the life characteristics regardless of the specific blue light-emitting portion.

[0137] In addition, since the structure is divided into a single stack structure including a blue light-emitting layer having a fluorescent dopant and a multiple stack structure in which a blue light-emitting layer having a fluorescent dopant and a blue light-emitting layer having a phosphorescent dopant are overlapped, color deviation due to a change in viewing angle can be reduced compared to when only a single stack structure or only a multiple stack structure is used, or when a blue light-emitting layer having a fluorescent dopant and a blue light-emitting layer having a phosphorescent dopant are overlapped with all blue light-emitting layers, and thus user perception of a change in viewing angle can be prevented or reduced.

[0138] Furthermore, since the dual structure has a common stack, the process for forming the single stack structure and the multi-stack structure is simplified, which has the advantage of reducing the process time, and therefore has the advantage of being environmentally friendly.

[0139] An emissive display device according to one embodiment of the present invention includes a bank provided on a substrate and exposing first to fourth light-emitting units, first to fourth anodes provided in the first to fourth light-emitting units, a first light-emitting stack provided on the first to fourth anodes, a charge generation layer and a second light-emitting stack provided on the first light-emitting stack corresponding to the fourth light-emitting unit, and a cathode provided on the first light-emitting stack of the first to third light-emitting units and the second light-emitting stack of the fourth light-emitting unit.

[0140] Each of the first and third light-emitting units may include a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer in the first light-emitting stack. The fourth light-emitting unit may include a first blue light-emitting layer in the first light-emitting stack, the same layer as the blue light-emitting layer, and a second blue light-emitting layer in the second light-emitting stack.

[0141] The third anode and the fourth anode may be connected laterally.

[0142] The first light-emitting stack may further include the first to fourth anodes, a first common layer located between the red light-emitting layer, the green light-emitting layer, the blue light-emitting layer, and the first blue light-emitting layer, and a second common layer located on the red light-emitting layer, the green light-emitting layer, the blue light-emitting layer, and the first blue light-emitting layer, and the second light-emitting stack may further include a hole transport functional layer between the charge generation layer and the second blue light-emitting layer, and an electron transport functional layer between the second blue light-emitting layer and the cathode.

[0143] The electron transport functional layer may be in contact with the second common layer on the bank between the third light emitting section and the fourth light emitting section.

[0144] The first common layer may include a hole injection layer, a hole transport layer, and an electron blocking layer, and each of the first light-emitting unit and the second light-emitting unit may further include a hole transport auxiliary layer between the hole transport layer and the electron blocking layer.

[0145] The thickness of the first light emitting stack may be such that the first light emitting section has the greatest thickness, and the third light emitting section and the fourth light emitting section have the smallest thickness.

[0146] The blue light-emitting layer and the first blue light-emitting layer can include a fluorescent dopant, and the second blue light-emitting layer can include a non-fluorescent dopant.

[0147] The non-fluorescent dopant can be a phosphorescent dopant or a thermally activated delayed fluorescent (TADF) dopant.

[0148] The combined area of ​​the third light emitting unit and the fourth light emitting unit may be larger than the area of ​​each of the first light emitting unit and the second light emitting unit, and the area ratio of the third light emitting unit and the fourth light emitting unit may be 1:10 to 10:1.

[0149] A light emitting display device according to another embodiment of the present invention includes: a bank provided on a substrate and exposing first to fourth light emitting units; first to fourth anodes provided on the first to fourth light emitting units, respectively; a first light emitting layer on the first anode, a second light emitting layer on the second anode, and a third light emitting layer on the third anode and the fourth anode; a charge generation layer and a fourth light emitting layer overlapping the fourth light emitting unit without overlapping the third light emitting unit and provided in this order on the third light emitting layer; and a cathode on the first light emitting layer, the second light emitting layer, the third light emitting layer, and the fourth light emitting layer on the first to third light emitting units and the fourth light emitting layer.

[0150] The third light-emitting layer and the fourth light-emitting layer may have an emission peak at 420 nm to 490 nm.

[0151] The third light-emitting layer can include a fluorescent dopant, and the fourth light-emitting layer can include a non-fluorescent dopant.

[0152] The non-fluorescent dopant can be a phosphorescent dopant or a delayed fluorescent dopant.

[0153] The device may further include a first common layer between the first to fourth anodes and the first to third light-emitting layers, a second common layer between the first to third light-emitting layers and the cathode, and an electron transport functional layer between the fourth light-emitting layer and the cathode.

[0154] In the first to third light emitting sections, the lower surface of the cathode may be in contact with the second common layer, and in the fourth light emitting section, the lower surface of the cathode may be in contact with the electron transport functional layer.

[0155] On the other hand, the present invention described above is not limited to the above-mentioned embodiments and accompanying drawings, and it will be apparent to those skilled in the art to which the present invention pertains that various substitutions, modifications and changes are possible within the scope of the technical idea of ​​the present invention. [Explanation of symbols]

[0156] 100 boards 120a~120d Anode R First light-emitting part G Second light-emitting part B1 Third light-emitting part B2 4th light emitting part RS, GS, BS1 1st light emitting stack BS2 Second Light Stack 151 Red light-emitting layer 152 Green light-emitting layer 153 First blue light-emitting layer 180 Second blue light-emitting layer 170 Charge generation layer 190 cathode 200 capping layer 300 Sealing Layer

Claims

1. a bank provided on the substrate and exposing the first to fourth light emitting units; first to fourth anodes provided in the first to fourth light emitting units, respectively; a first light-emitting stack provided on the first to fourth anodes; a charge generating layer and a second light emitting stack provided on the first light emitting stack corresponding to the fourth light emitting portion; a cathode provided on the first light-emitting stack of the first to third light-emitting units and the second light-emitting stack of the fourth light-emitting unit.

2. each of the first to third light-emitting units includes a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer in the first light-emitting stack; The light emitting display device of claim 1 , wherein the fourth light emitting unit includes a first blue light emitting layer in the first light emitting stack, the first blue light emitting layer being the same layer as the blue light emitting layer, and a second blue light emitting layer in the second light emitting stack.

3. The light emitting display device of claim 2 , wherein the third anode and the fourth anode are connected in a horizontal direction.

4. the first light-emitting stack further includes a first common layer located between the first to fourth anodes and the red light-emitting layer, the green light-emitting layer, the blue light-emitting layer, and the first blue light-emitting layer, and a second common layer located on the red light-emitting layer, the green light-emitting layer, the blue light-emitting layer, and the first blue light-emitting layer; 3. The light-emitting display device of claim 2, wherein the second light-emitting stack further comprises a hole transport functional layer between the charge generation layer and the second blue light-emitting layer, and an electron transport functional layer between the second blue light-emitting layer and the cathode.

5. The light-emitting display device according to claim 4 , wherein the electron transport functional layer is in contact with the second common layer on the bank between the third light-emitting section and the fourth light-emitting section.

6. the first common layer includes a hole injection layer, a hole transport layer, and an electron blocking layer; The light emitting display device of claim 4 , wherein each of the first light emitting unit and the second light emitting unit further comprises a hole transport assisting layer between the hole transport layer and the electron blocking layer.

7. The light emitting display device of claim 1 , wherein the first light emitting section has the largest thickness, and the third light emitting section and the fourth light emitting section have the smallest thickness.

8. the blue light-emitting layer and the first blue light-emitting layer contain a fluorescent dopant; The light emitting display device of claim 1 , wherein the second blue light emitting layer comprises a non-fluorescent dopant.

9. The light emitting display device of claim 8 , wherein the non-fluorescent dopant is a phosphorescent dopant or a thermally activated delayed fluorescent (TADF) dopant.

10. a combined area of ​​the third light-emitting unit and the fourth light-emitting unit is larger than an area of ​​each of the first light-emitting unit and the second light-emitting unit; The light emitting display device of claim 1, wherein an area ratio of the third light emitting portion to the fourth light emitting portion is 1:10 to 10:

1.

11. a bank provided on the substrate and exposing the first to fourth light emitting units; first to fourth anodes provided in the first to fourth light emitting units, respectively; a first light-emitting layer on the first anode, a second light-emitting layer on the second anode, and a third light-emitting layer on the third anode and the fourth anode; a charge generation layer and a fourth light-emitting layer, which overlap the fourth light-emitting unit without overlapping the third light-emitting unit, and are provided in this order on the third light-emitting layer; a cathode on the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer on the first to third light-emitting portions, and on the fourth light-emitting layer.

12. The light-emitting display device according to claim 11, wherein the third light-emitting layer and the fourth light-emitting layer have emission peaks in the range of 420 nm to 490 nm.

13. The light-emitting display device of claim 12 , wherein the third light-emitting layer includes a fluorescent dopant and the fourth light-emitting layer includes a non-fluorescent dopant.

14. The light-emitting display device according to claim 13 , wherein the non-fluorescent dopant is a phosphorescent dopant or a delayed fluorescent dopant.

15. a first common layer between the first to fourth anodes and the first to third light-emitting layers; a second common layer between the first to third light-emitting layers and the cathode; The light-emitting display device according to claim 11 , further comprising: an electron transport functional layer between the fourth light-emitting layer and the cathode.

16. 16. The light-emitting display device according to claim 15, wherein in the first to third light-emitting sections, the lower surface of the cathode is in contact with the second common layer, and in the fourth light-emitting section, the lower surface of the cathode is in contact with the electron transport functional layer.

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