Electroluminescent display device

Abstract

There is provided an electroluminescent display device including: a first sub-pixel including a first light emitting region; a first electrode disposed in the first sub-pixel; a light emitting layer disposed on the first electrode; a second electrode disposed on the light emitting layer; the packaging layer is arranged on the second electrode; and a cyan color filter disposed on the encapsulation layer, in which the first light emitting region includes a first sub-light emitting region and a second sub-light emitting region, the cyan color filter includes a first sub-color filter corresponding to the first sub-light emitting region and a second sub-color filter corresponding to the second sub-light emitting region, the first sub-color filter transmits green light, and the second sub-color filter transmits blue light. The present invention can realize an electroluminescent display device having high efficiency, low reflection, and high color reproducibility.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of Korean Patent Application No. 10 - 2023 - 0194541, filed on December 28, 2023, which is incorporated herein by reference in its entirety as if fully set forth herein. Technical field

[0003] The present invention relates to an electroluminescent display device. Background art

[0004] An electroluminescent display device includes a first electrode, a second electrode, and a light - emitting layer disposed between the first electrode and the second electrode, and displays an image by emitting light from the light - emitting layer through an electric field between the two electrodes.

[0005] Such an electroluminescent display device may include red sub - pixels, green sub - pixels, and blue sub - pixels to display images of various colors.

[0006] However, there are limitations in the color reproducibility of an electroluminescent display device having only the above - mentioned three sub - pixels. Summary of the invention

[0007] In view of the above problems, the present invention has been made, and an object of the present invention is to provide an electroluminescent display device capable of improving color reproducibility.

[0008] According to an aspect of the present invention, the above and other objects can be achieved by providing an electroluminescent display device including: a first sub - pixel including a first light - emitting region; a first electrode disposed in the first sub - pixel; a light - emitting layer disposed on the first electrode; a second electrode disposed on the light - emitting layer; a encapsulation layer disposed on the second electrode; and a cyan color filter disposed on the encapsulation layer, wherein the first light - emitting region includes a first sub - light - emitting region and a second sub - light - emitting region, the cyan color filter includes a first sub - color filter corresponding to the first sub - light - emitting region and a second sub - color filter corresponding to the second sub - light - emitting region, and the first sub - color filter transmits green light and the second sub - color filter transmits blue light.

[0009] In addition, according to an aspect of the present invention, the above and other objects can be achieved by providing an electroluminescent display device including: a plurality of sub-pixels including a first sub-pixel having a first light-emitting region and a second sub-pixel having a second light-emitting region; a first electrode disposed in each of the first sub-pixel and the second sub-pixel; a light-emitting layer disposed on the first electrode; a second electrode disposed on the light-emitting layer; and a plurality of color filters including a first color filter corresponding to the first light-emitting region and a second color filter corresponding to the second light-emitting region, wherein the first light-emitting region includes a first sub-light-emitting region and a second sub-light-emitting region that emit lights of different colors, and the first color filter includes a first sub-color filter corresponding to the first sub-light-emitting region and a second sub-color filter corresponding to the second sub-light-emitting region. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic plan view of an electroluminescent display device according to an embodiment of the present invention.

[0011] Figures 2 to 5 is a schematic plan view of a first light-emitting region that emits cyan light according to embodiments of the present invention.

[0012] Figure 6 is a partial cross-sectional view of a first light-emitting region that emits cyan light according to an embodiment of the present invention.

[0013] Figure 7 is a partial cross-sectional view of a second light-emitting region that emits blue light according to an embodiment of the present invention.

[0014] Figure 8 is a schematic cross-sectional view of an electroluminescent display device according to an embodiment of the present invention.

[0015] Figure 9 is a graph showing color reproducibility according to a comparative example and an embodiment.

[0016] Figure 10 is a graph showing changes in color reproducibility caused by changing the ratio of the area of the first sub-light-emitting region to the area of the second sub-light-emitting region while keeping the ratio of the first thickness of the first sub-color filter to the second thickness of the second sub-color filter at 1:1.

[0017] Figure 11 is a graph showing changes in color reproducibility caused by changing the ratio of the area of the first sub-light-emitting region to the area of the second sub-light-emitting region while keeping the ratio of the first thickness of the first sub-color filter to the second thickness of the second sub-color filter at 2:1.

[0018] Figure 12A shows the spectra of each wavelength when applying a conventional first electrode; Figure 12B shows the spectra of each wavelength when applying a low-reflection first electrode that uses a first sub-metal layer with a high deposition rate; Figure 12C shows the spectra of each wavelength when applying a low-reflection first electrode that uses a second sub-metal layer with a low deposition rate.

[0019] Figure 13A shows the spectra of applying a green filter to Figure 12A the spectra, Figure 13B shows the spectra of applying a green filter to Figure 12B the spectra, Figure 13C shows the spectra of applying a green filter to Figure 12C the spectra.

[0020] Figure 14A shows the spectra of applying a blue filter to Figure 12A the spectra, Figure 14B shows the spectra of applying a blue filter to Figure 12B the spectra, Figure 14C shows the spectra of applying a blue filter to Figure 12C the spectra.

[0021] Figure 15A is a graph showing the variation of the refractive index n of a first sub-metal layer with a relatively high deposition rate and a second sub-metal layer with a relatively low deposition rate in each wavelength band.

[0022] Figure 15B is a graph showing the variation of the refractive index k of a first sub-metal layer with a relatively high deposition rate and a second sub-metal layer with a relatively low deposition rate in each wavelength band.

[0023] Figure 15C is a graph showing the variation of the reflectivity of a first sub-metal layer with a relatively high deposition rate and a second sub-metal layer with a relatively low deposition rate in each wavelength band.

[0024] Figure 15D is a graph showing a first sub-metal layer with a relatively high deposition rate and a second sub-metal layer with Graph of the change in transmittance of the second sub-metal layer with a relatively low deposition rate in each wavelength band.

[0025] Figure 15E shows a graph of the first sub-metal layer with a relatively high deposition rate and the second sub-metal layer with a relatively low deposition rate, showing the change in absorbance in each wavelength band. Detailed Description of the Invention

[0026] The advantages, features, and implementation methods of the present invention will be clarified by the following embodiments described with reference to the accompanying drawings. However, the present invention can be implemented in different forms and should not be construed as limited to the embodiments listed herein. Instead, these embodiments are provided to make the present disclosure comprehensive and complete, and to fully convey the scope of the present invention to those skilled in the art. In addition, the present invention is only limited by the scope of the claims.

[0027] The shapes, sizes, ratios, angles, and quantities disclosed in the drawings for describing the embodiments of the present invention are merely examples, and thus the present invention is not limited to the details of the illustrations. The same reference numerals refer to the same elements throughout. In the following description, when it is determined that a detailed description of a related known function or configuration will unnecessarily obscure the focus of the present invention, the detailed description will be omitted. When using "comprising", "having", and "including" to describe in the present invention, other parts may be added unless "only" is used. Singular terms may include plural forms unless there is a contrary indication.

[0028] When interpreting an element, although not explicitly described, the element is interpreted as including an error range.

[0029] When describing positional relationships, for example, when the positional relationship is described as "on...", "above...", "below...", and "after...", one or more other parts may be provided between the two parts, unless "exactly" or "directly" is used.

[0030] When describing temporal relationships, for example, when the chronological relationship is described as "after...", "subsequently", "then", and "before...", discontinuous cases may be included, unless "exactly" or "directly" is used.

[0031] It will be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present invention, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element.

[0032] Those skilled in the art can fully understand that the features of the embodiments of the present invention can be partially or wholly combined or combined with each other, and various interoperations and drives can be carried out with each other technically. The embodiments of the present invention can be implemented independently of each other, or implemented jointly in a mutually dependent relationship.

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0034] Figure 1 is a schematic plan view of an electroluminescent display device according to an embodiment of the present invention.

[0035] As Figure 1 shown, an electroluminescent display device according to an embodiment of the present invention includes a plurality of sub-pixels (a first sub-pixel, a second sub-pixel, a third sub-pixel, a fourth sub-pixel).

[0036] The plurality of sub-pixels (a first sub-pixel, a second sub-pixel, a third sub-pixel, a fourth sub-pixel) include a plurality of light-emitting regions EA1, EA2, EA3, EA4.

[0037] Specifically, the first sub-pixel (the first sub-pixel) includes a first light-emitting region EA1, the second sub-pixel (the second sub-pixel) includes a second light-emitting region EA2, the third sub-pixel (the third sub-pixel) includes a third light-emitting region EA3, and the fourth sub-pixel (the fourth sub-pixel) includes a fourth light-emitting region EA4.

[0038] A bank 400 is provided between the light-emitting regions EA1, EA2, EA3, EA4. The bank 400 may have a matrix structure extending in the lateral and longitudinal directions. The light-emitting regions EA1, EA2, EA3, EA4 are defined by the bank 400.

[0039] The first light-emitting region EA1 can emit cyan (C) light, the second light-emitting region EA2 can emit blue (B) light, the third light-emitting region EA3 can emit green (G) light, and the fourth light-emitting region EA4 can emit red (R) light.

[0040] Although the drawings show that the fourth light-emitting region EA4, the third light-emitting region EA3, the first light-emitting region EA1, and the second light-emitting region EA2 are arranged in sequence from left to right, this is not limited thereto.

[0041] The first sub-pixel (the 1st sub-pixel) can be disposed between the second sub-pixel (the 2nd sub-pixel) and the third sub-pixel (the 3rd sub-pixel). That is to say, the second sub-pixel (the 2nd sub-pixel) can be disposed on one side of the first sub-pixel (the 1st sub-pixel), for example, on the right side of the first sub-pixel (the 1st sub-pixel), and the third sub-pixel (the 3rd sub-pixel) can be disposed on the other side of the first sub-pixel (the 1st sub-pixel), for example, on the left side of the first sub-pixel (the 1st sub-pixel). Therefore, the first light-emitting region EA1 that emits cyan (C) light can be disposed between the second light-emitting region EA2 that emits blue (B) light and the third light-emitting region EA3 that emits green (G) light.

[0042] As described later, the first light-emitting region EA1 that emits cyan (C) light includes a first sub-light-emitting region that emits green light and a second sub-light-emitting region that emits blue light. Therefore, when the first light-emitting region EA1 is located between the second light-emitting region EA2 and the third light-emitting region EA3, even if leakage current occurs between adjacent sub-pixels (the 1st sub-pixel, the 2nd sub-pixel, the 3rd sub-pixel), the problem of color mixing can be minimized. However, the present invention is not limited thereto, and the first sub-pixel (the 1st sub-pixel) can be disposed between the third sub-pixel (the 3rd sub-pixel) and the fourth sub-pixel (the 4th sub-pixel), or can be disposed between the second sub-pixel (the 2nd sub-pixel) and the fourth sub-pixel (the 4th sub-pixel).

[0043] Figures 2 to 5 It is a schematic plan view of the first light-emitting region that emits cyan light according to various embodiments of the present invention.

[0044] As Figures 2 to 5 shown, the first light-emitting region EA1 includes a first sub-light-emitting region EA11 and a second sub-light-emitting region EA12.

[0045] The first sub-light-emitting region EA11 is a region that emits green light, and the second sub-light-emitting region EA12 is a region that emits blue light. The first sub-light-emitting region EA11 and the second sub-light-emitting region EA12 are in contact with each other.

[0046] The first sub-light-emitting region EA11 and the second sub-light-emitting region EA12 can be disposed in various ways.

[0047] According to an embodiment, as Figure 2 shown, the second sub-light-emitting region EA12 can be disposed on one side of the first sub-light-emitting region EA11, for example, disposed below the first sub-light-emitting region EA11. For example, when the first light-emitting region EA1 has a rectangular structure with a longer longitudinal direction than the transverse direction, the second sub-light-emitting region EA12 has a bar structure extending in the transverse direction, and the first sub-light-emitting region EA11 can be disposed on the upper side of the second sub-light-emitting region EA12 while being in contact with the upper surface of the second sub-light-emitting region EA12.

[0048] According to another embodiment, as shown in Figure 3 , two first sub-light-emitting regions EA11 may be arranged to be vertically spaced apart from each other with the second sub-light-emitting region EA12 therebetween. As an example, when the first light-emitting region EA1 has a rectangular structure with a length in the longitudinal direction longer than that in the transverse direction, the second sub-light-emitting region EA12 has a strip-shaped structure extending in the transverse direction, and the two first sub-light-emitting regions EA11 may be arranged on the upper side and the lower side of the second sub-light-emitting region EA12 while being in contact with the upper surface and the lower surface of the second sub-light-emitting region EA12.

[0049] According to another embodiment, as shown in Figure 4 , two first sub-light-emitting regions EA11 may be arranged to be horizontally spaced apart from each other with the second sub-light-emitting region EA12 therebetween. As an example, when the first light-emitting region EA1 has a rectangular structure with a length in the longitudinal direction longer than that in the transverse direction, the second sub-light-emitting region EA12 has a strip-shaped structure extending in the longitudinal direction, and the two first sub-light-emitting regions EA11 may be arranged on the left side and the right side of the second sub-light-emitting region EA12 while being in contact with the left surface and the right surface of the second sub-light-emitting region EA12.

[0050] According to another embodiment, as shown in Figure 5 , the first sub-light-emitting region EA11 may be arranged to entirely surround the second sub-light-emitting region EA12. As an example, when the first light-emitting region EA1 has a rectangular structure with a length in the longitudinal direction longer than that in the transverse direction, the second sub-light-emitting region EA12 has a rectangular or square structure in the center of the first sub-light-emitting region EA11. In addition, the first sub-light-emitting region EA11 may have a structure surrounding the second sub-light-emitting region EA12 while being in contact with the entire outer periphery of the second sub-light-emitting region EA12.

[0051] In Figures 2 to 5 , the area of the first sub-light-emitting region EA11 may preferably be larger than the area of the second sub-light-emitting region EA12.

[0052] Specifically, in terms of color reproducibility, the ratio of the area of the first sub-light-emitting region EA11 to the area of the second sub-light-emitting region EA12 may preferably be in the range of 7:3 to 9:1, which will be described later.

[0053] Figure 6 is a partial cross-sectional view of the first light-emitting region EA1 that emits cyan (C) light according to an embodiment of the present invention, Figure 7 is a partial cross-sectional view of the second light-emitting region EA2 that emits blue light according to an embodiment of the present invention.

[0054] As shown in Figure 6As shown in the figure, the first light-emitting region EA1 includes a first electrode 510, a light-emitting layer 600, a second electrode 700, a packaging layer 750, and a first color filter 810.

[0055] The first electrode 510 can be used as an anode.

[0056] The first electrode 510 can have a first thickness t11, can include multiple layers, and can have low reflectivity characteristics. For example, the first electrode 510 can include a first transparent conductive layer 511; a first metal layer 512; a second transparent conductive layer 513; second metal layers 514a, 514b; and a third transparent conductive layer 515.

[0057] The first transparent conductive layer 511 can be formed of ITO, but is not limited thereto. The first metal layer 512 is disposed on the first transparent conductive layer 511 and can be formed of Ag, but is not limited thereto. The second transparent conductive layer 513 is disposed on the first metal layer 512 and can be formed of a material different from that of the first transparent conductive layer 511, such as IZO, but is not limited thereto. The second metal layers 514a, 514b are disposed on the second transparent conductive layer 513 and can be formed of a material different from that of the first metal layer 512, such as Al, but is not limited thereto. The third transparent conductive layer 515 is disposed on the second metal layers 514a, 514b and can be formed of the same material as the first transparent conductive layer 511, such as ITO, but is not limited thereto.

[0058] The thickness of the second transparent conductive layer 513 can be thicker than the thickness of the first transparent conductive layer 511 and the thickness of the third transparent conductive layer 515, and the thickness of the first transparent conductive layer 511 can be the same as the thickness of the third transparent conductive layer 515. In addition, the thickness of the second metal layers 514a, 514b can be thinner than the thickness of the first metal layer 512 and the thickness of the first transparent conductive layer 511, and the thickness of the first metal layer 512 can be thicker than the thickness of the second transparent conductive layer 513, but is not limited thereto.

[0059] The first transparent conductive layer 511, the first metal layer 512, the second transparent conductive layer 513, and the third transparent conductive layer 515 are continuously disposed in the first sub-light-emitting region EA11 and the second sub-light-emitting region EA12 while overlapping with the entire first sub-light-emitting region EA11 and the entire second sub-light-emitting region EA12.

[0060] The second metal layers 514a, 514b include a first sub-metal layer 514a and a second sub-metal layer 514b. The first sub-metal layer 514a overlaps with the first sub-light-emitting region EA11, and the second sub-metal layer 514b overlaps with the second sub-light-emitting region EA12. Therefore, the area of the first sub-metal layer 514a is larger than the area of the second sub-metal layer 514b.

[0061] The first sub-metal layer 514a and the second sub-metal layer 514b may be in contact with each other at the boundary between the first sub-light-emitting region EA11 and the second sub-light-emitting region EA12.

[0062] The first sub-metal layer 514a and the second sub-metal layer 514b may be formed of the same material, such as Al. In addition, the first sub-metal layer 514a and the second sub-metal layer 514b may be formed by the same deposition process, such as a sputtering process.

[0063] However, in terms of color reproducibility, the deposition rate of the first sub-metal layer 514a may preferably be higher than that of the second sub-metal layer 514b. For example, when the deposition rate of the first sub-metal layer 514a is in to the range, the full width at half maximum (FWHM) of the green light in the first sub-light-emitting region EA11 decreases, thus improving color reproducibility. In addition, when the deposition rate of the second sub-metal layer 514b is in to the range, the full width at half maximum (FWHM) of the blue light in the second sub-light-emitting region EA12 decreases, thus improving color reproducibility. The deposition rates of the first sub-metal layer 514a and the second sub-metal layer 514b will be described in detail later.

[0064] The first electrode 510 includes the second metal layers 514a, 514b and has low reflection characteristics, and does not necessarily require a five-layer structure.

[0065] The light-emitting layer 600 is disposed on the first electrode 510. The light-emitting layer 600 may emit white light. The light-emitting layer 600 may include a first stack that emits light of a first color, a second stack that emits light of a second color, and a charge generation layer disposed between the first stack and the second stack. The first color may be one of blue and yellow-green, and the second color may be the other of blue and yellow-green.

[0066] The second electrode 700 is disposed on the light-emitting layer 600. The second electrode 700 may be used as a cathode. The second electrode 700 may include a transparent electrode or a semi-transparent electrode.

[0067] The encapsulation layer 750 is disposed on the second electrode 700. The encapsulation layer 750 may include an inorganic insulating layer and an organic insulating layer.

[0068] The first color filter 810 is disposed on the encapsulation layer 750. The first color filter 810 transmits cyan light.

[0069] The first color filter 810 includes a first sub-color filter 811 and a second sub-color filter 812. The first sub-color filter 811 overlaps with the first sub-light-emitting region EA11, and the second sub-color filter 812 overlaps with the second sub-light-emitting region EA12. The first sub-color filter 811 and the second sub-color filter 812 may be in contact with each other at the boundary between the first sub-light-emitting region EA11 and the second sub-light-emitting region EA12.

[0070] The first sub-color filter 811 may be formed of a green color filter that transmits green light, and the second sub-color filter 812 may be formed of a blue color filter that transmits blue light.

[0071] When the area of the first sub-color filter 811 is larger than the area of the second sub-color filter 812, it may be advantageous in terms of color reproducibility.

[0072] In terms of color reproducibility, it is advantageous that the first thickness t21 of the first sub-color filter 811 is thicker than the second thickness t22 of the second sub-color filter 812. For example, in terms of color reproducibility and economic feasibility, the ratio of the first thickness t21 of the first sub-color filter 811 to the second thickness t22 of the second sub-color filter 812 may preferably be in the range of 1.8:1 to 2:1, which will be described later.

[0073] The upper surfaces of the first sub-color filter 811 and the second sub-color filter 812 may be formed at the same height. Accordingly, the lower surface of the first sub-color filter 811 may be positioned closer to the second electrode 700 than the lower surface of the second sub-color filter 812.

[0074] As Figure 7 shown, the second light-emitting region EA2 includes a first electrode 520, a light-emitting layer 600, a second electrode 700, a packaging layer 750, and a second color filter 820.

[0075] The first electrode 520 may be used as an anode.

[0076] The first electrode 520 may have a second thickness t12 and may include multiple layers.

[0077] The second thickness t12 of the first electrode 520 of the second light-emitting region EA2 may be thinner than the first thickness t11 of the first electrode 510 of the first light-emitting region EA1 described above.

[0078] The first electrode 520 of the second light-emitting region EA2 may include a first transparent conductive layer 521; a first metal layer 522; and a second transparent conductive layer 523.

[0079] The first transparent conductive layer 521 can be made of ITO, but is not limited thereto. The first metal layer 522 is disposed on the first transparent conductive layer 521 and can be made of Ag, but is not limited thereto. The second transparent conductive layer 523 is disposed on the first metal layer 522 and can be made of the same material as the first transparent conductive layer 521, such as ITO, but is not limited thereto.

[0080] The thickness of the first transparent conductive layer 521 can be equal to the thickness of the second transparent conductive layer 523, and the thickness of the first metal layer 522 can be thicker than the thickness of the first transparent conductive layer 521, but is not limited thereto.

[0081] The first transparent conductive layer 521 of the second light-emitting region EA2 can be formed of the same material and the same thickness as the first transparent conductive layer 511 of the first light-emitting region EA1.

[0082] The first metal layer 522 of the second light-emitting region EA2 can be formed of the same material and the same thickness as the first metal layer 512 of the first light-emitting region EA1.

[0083] The second transparent conductive layer 523 of the second light-emitting region EA2 can be formed of the same material and the same thickness as the third transparent conductive layer 515 of the first light-emitting region EA1.

[0084] Therefore, the second transparent conductive layer 513 and the second metal layers 514a and 514b of the first light-emitting region EA1 may not be provided in the second light-emitting region EA2.

[0085] The light-emitting layer 600 of the second light-emitting region EA2 can be formed of the same material as the light-emitting layer 600 of the first light-emitting region EA1, the second electrode 700 of the second light-emitting region EA2 can be formed of the same material as the second electrode 700 of the first light-emitting region EA1, and the encapsulation layer 750 of the second light-emitting region EA2 can be formed of the same material as the encapsulation layer 750 of the first light-emitting region EA1.

[0086] The second color filter 820 of the second light-emitting region EA2 can be formed of a blue color filter that transmits blue light.

[0087] The third thickness t23 of the second color filter 820 of the second light-emitting region EA2 can be thinner than the first thickness t21 of the first sub-color filter 811 of the first light-emitting region EA1 and can be the same as the second thickness t22 of the second sub-color filter 812 of the first light-emitting region EA1. Alternatively, the third thickness t23 of the second color filter 820 of the second light-emitting region EA2 can be thinner than the second thickness t22 of the second sub-color filter 812 of the first light-emitting region EA1.

[0088] Figure 8 is a schematic cross-sectional view of an electroluminescent display device according to an embodiment of the present invention.

[0089] As shown Figure 8 in the figure, an electroluminescent display device according to an embodiment of the present invention includes a first substrate 100; a circuit element layer 200; a passivation layer 310; a planarization layer 320; a bank 400; first electrodes 510, 520, 530, 540; a light-emitting layer 600; a second electrode 700; a packaging layer 750; color filters 810, 820, 830, 840; and a second substrate 900.

[0090] The first substrate 100 may be made of glass, plastic, or semiconductor material, but is not limited thereto. The electroluminescent display device according to an embodiment of the present invention may be a top-emission type, so that not only transparent materials but also opaque materials can be used as the material of the first substrate 100.

[0091] The circuit element layer 200 is disposed on the first substrate 100.

[0092] The circuit element layer 200 includes driving thin-film transistors provided for each of the first to fourth sub-pixels (the 1st sub-pixel, the 2nd sub-pixel, the 3rd sub-pixel, the 4th sub-pixel).

[0093] The driving thin-film transistor includes an active layer 210 disposed on the first substrate 100, a gate insulating layer 220 disposed on the active layer 210, a gate electrode 230 disposed on the gate insulating layer 220, an interlayer insulating layer 240 disposed on the gate electrode 230, and a source electrode 250 and a drain electrode 260 disposed on the interlayer insulating layer 240. The source electrode 250 and the drain electrode 260 may be connected to one side and the other side of the active layer 210 through holes provided in the interlayer insulating layer 240 and the gate insulating layer 220.

[0094] Although the driving thin-film transistor is shown in the figure as having a top-gate structure in which the gate electrode 230 is disposed on the active layer 210, the present invention may include a driving thin-film transistor having a bottom-gate structure in which the gate electrode 230 is disposed below the active layer 210. In addition, although the gate insulating layer 220 is formed on the entire surface of the first substrate 100 in the figure, the gate insulating layer 220 may be patterned in the same shape as the gate electrode 230 below the gate electrode 230. The driving thin-film transistor may be varied in various forms known in the art.

[0095] In addition, although not shown, the circuit element layer 200 may further include various signal lines, various thin-film transistors, and capacitors. The signal lines include gate lines, data lines, power supply lines, and reference lines. The thin-film transistors include switching thin-film transistors and sensing thin-film transistors.

[0096] The switching thin film transistor switches according to a gate signal supplied to a gate line to supply a data voltage supplied from a data line to a driving thin film transistor.

[0097] The driving thin film transistor switches according to the data voltage supplied from the switching thin film transistor. The driving thin film transistor generates a data current from a power supply supplied from a power line and supplies the data current to the first electrodes 510, 520, 530, 540.

[0098] The sensing thin film transistor senses a threshold voltage deviation of the driving thin film transistor that causes image quality degradation. In addition, the sensing thin film transistor supplies the current of the driving thin film transistor to a reference line in response to a sensing control signal supplied from a gate line or a separate sensing line.

[0099] The capacitor holds the data voltage supplied to the driving thin film transistor for one frame, and the capacitor is connected to the gate terminal and the source terminal of the driving thin film transistor, respectively.

[0100] The passivation layer 310 is disposed on the circuit element layer 200. Specifically, the passivation layer 310 is disposed on the source electrode 250 and the drain electrode 260.

[0101] The planarization layer 320 is disposed on the passivation layer 310.

[0102] The passivation layer 310 and the planarization layer 320 may include contact holes, the source electrode 250 may be exposed through the contact holes, and the first electrodes 510, 520, 530, 540 may be connected to the exposed source electrode 250 through the contact holes. In some cases, the drain electrode 260 may be exposed through the contact holes provided in the passivation layer 310 and the planarization layer 320, and the first electrodes 510, 520, 530, 540 may be connected to the exposed drain electrode 260 through the contact holes.

[0103] The bank 400 is disposed on the planarization layer 320 and is formed at the boundaries between the first to fourth sub-pixels (the first sub-pixel, the second sub-pixel, the third sub-pixel, the fourth sub-pixel). The bank 400 is disposed on the first electrodes 510, 520, 530, 540 to cover the edges of the first electrodes 510, 520, 530, 540, and light emitting regions EA1, EA2, EA3, EA4 may be defined by the bank 400. That is, the portions of the first electrodes 510, 520, 530, 540 exposed by the bank 400 may become the light emitting regions EA1, EA2, EA3, EA4. Accordingly, the first light emitting region EA1 is provided in the first sub-pixel (the first sub-pixel), the second light emitting region EA2 is provided in the second sub-pixel (the second sub-pixel), the third light emitting region EA3 is provided in the third sub-pixel (the third sub-pixel), and the fourth light emitting region EA4 is provided in the fourth sub-pixel (the fourth sub-pixel).

[0104] The first electrodes 510, 520, 530, 540 are disposed on the planarization layer 320 for each of the first to fourth sub-pixels (the 1st sub-pixel, the 2nd sub-pixel, the 3rd sub-pixel, the 4th sub-pixel).

[0105] The first electrodes 510, 520, 530, 540 are connected to the source electrode 250 or the drain electrode 260 through contact holes provided in the passivation layer 310 and the planarization layer 320.

[0106] The thickness of the first electrode 510 of the first sub-pixel (the 1st sub-pixel) is thicker than the thicknesses of the first electrodes 520, 530, 540 of the second to fourth sub-pixels (the 2nd sub-pixel, the 3rd sub-pixel, the 4th sub-pixel), and the first electrodes 520, 530, 540 of the second to fourth sub-pixels (the 2nd sub-pixel, the 3rd sub-pixel, the 4th sub-pixel) may have the same thickness.

[0107] The reflectivity of the first electrode 510 of the first sub-pixel (the 1st sub-pixel) may be lower than the reflectivities of the first electrodes 520, 530, 540 of the second to fourth sub-pixels (the 2nd sub-pixel, the 3rd sub-pixel, the 4th sub-pixel).

[0108] The first electrode 510 of the first sub-pixel (the 1st sub-pixel) may include a first transparent conductive layer 511; a first metal layer 512; a second transparent conductive layer 513; second metal layers 514a, 514b; and a third transparent conductive layer 515, as Figure 6 shown.

[0109] The first electrodes 520, 530, 540 of the second to fourth sub-pixels (the 2nd sub-pixel, the 3rd sub-pixel, the 4th sub-pixel) may have the same structure and may include a first transparent conductive layer 521; a first metal layer 522; and a second transparent conductive layer 523, as Figure 7 shown.

[0110] The light-emitting layer 600 is disposed on the first electrodes 510, 520, 530, 540 and the bank 400. The light-emitting layer 600 may emit white light, but is not limited thereto. The light-emitting layer 600 may be disposed in each of the sub-pixels (the 1st sub-pixel, the 2nd sub-pixel, the 3rd sub-pixel, the 4th sub-pixel) and at their boundaries. The light-emitting layer 600 may be continuous and unbroken among all the sub-pixels (the 1st sub-pixel, the 2nd sub-pixel, the 3rd sub-pixel, the 4th sub-pixel).

[0111] The light-emitting layer 600 may include a first stack 610, a charge generation layer 620, and a second stack 630. The first stack 610 may be disposed on the first electrodes 510, 520, 530, 540 and the bank 400, the charge generation layer 620 may be disposed on the first stack 610, and the second stack 630 may be disposed on the charge generation layer 620.

[0112] The first stack 610 may emit one of blue light and yellowish-green light, and the second stack 630 may emit the other of blue light and yellowish-green light. For example, the first stack 610 may emit blue light, and the second stack 630 may emit yellowish-green light. In some cases, the second stack 630 may emit a mixed light of yellowish-green light and red light.

[0113] Each of the first stack 610 and the second stack 630 may include at least one of a hole injection layer, a hole transport layer, an electron blocking layer, an organic light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0114] The charge generation layer 620 may include an N-type charge generation layer disposed on the first stack 610 to provide electrons to the first stack 610, and a P-type charge generation layer disposed on the N-type charge generation layer to provide holes to the second stack 630.

[0115] As shown in the figure, the light-emitting layer 600 is not limited to a two-stack structure, and may have a stack structure including three or more stacks and two or more charge generation layers.

[0116] The encapsulation layer 750 is disposed on the light-emitting layer 600.

[0117] The encapsulation layer 750 may have a three-layer structure of a first inorganic insulating layer, an organic insulating layer disposed on the first inorganic insulating layer, and a second inorganic insulating layer disposed on the organic insulating layer, but is not limited thereto. The encapsulation layer 750 may be continuous between all sub-pixels (the first sub-pixel, the second sub-pixel, the third sub-pixel, the fourth sub-pixel) without interruption.

[0118] The color filters 810, 820, 830, 840 are disposed on the encapsulation layer 750 for each sub-pixel (the first sub-pixel, the second sub-pixel, the third sub-pixel, the fourth sub-pixel).

[0119] The first color filter 810 overlaps with the first light-emitting region EA1 in the first sub-pixel (the first sub-pixel), the second color filter 820 overlaps with the second light-emitting region EA2 in the second sub-pixel (the second sub-pixel), the third color filter 830 overlaps with the third light-emitting region EA3 in the third sub-pixel (the third sub-pixel), and the fourth color filter 840 overlaps with the fourth light-emitting region EA4 in the fourth sub-pixel (the fourth sub-pixel).

[0120] The first color filter 810 can transmit cyan light and, as described above, includes a first sub-filter 811 that transmits green light and a second sub-filter 812 that transmits blue light, as Figure 6 shown therein.

[0121] The second color filter 820 can be formed of a blue color filter that transmits blue light, as Figure 7 shown therein.

[0122] The third color filter 830 can be formed of a green color filter that transmits green light, and the fourth color filter 840 can be formed of a red color filter that transmits red light. The thickness of the third color filter 830 and the thickness of the fourth color filter 840 can be the same as the thickness of the second color filter 820.

[0123] The heights of the upper surfaces of each of the color filters 810, 820, 830, and 840 can be the same as each other.

[0124] The second substrate 900 is disposed on the color filters 810, 820, 830, and 840. The second substrate 900 is made of a transparent material. After the color filters 810, 820, 830, and 840 are formed on the second substrate 900, the color filters 810, 820, 830, and 840 can be adhered while facing the encapsulation layer 750.

[0125] Figure 9 is a graph showing color reproducibility according to a comparative example and an embodiment, and Table 1 below shows the efficiency, color coordinates, color reproducibility, and optical characteristics of each sub-pixel according to the comparative example and the embodiment.

[0126] In Figure 9 and Table 1, the comparative example relates to an electroluminescent display device having a first sub-pixel that emits cyan light in a structure not provided with Figure 8 , and the embodiment relates to a case where the first electrode 510 and the first color filter 810 in which Figure 6 are applied to the structure in which Figure 8 , the ratio of the area of the first sub-light-emitting region EA11 to the area of the second sub-light-emitting region EA12 is 8.5:1.5, and the ratio of the first thickness t21 of the first sub-filter 811 to the second thickness t22 of the second sub-filter 812 is 2:1.

[0127] In Figure 9 and Table 1, the comparative example relates to an electroluminescent display device having a first sub-pixel that emits cyan light in a structure not including Figure 8 as described above, and the embodiment relates to a case where the first electrode 510 and the first color filter 810 in which Figure 6 are applied to Figure 8Regarding the structure of the [specific content]. Specifically, in the embodiment, the ratio of the area of the first sub-light-emitting region EA11 to the area of the second sub-light-emitting region EA12 is 8.5:1.5, and the ratio of the first thickness t21 of the first sub-color filter 811 to the second thickness t22 of the second sub-color filter 812 is 2:1.

[0128] As shown in Table 1 below, it can be seen that each sub-pixel of the embodiment has improved efficiency (Cd / A) compared to the comparative example.

[0129] In addition, from Table 1 and Figure 9 it can be seen that in the case of the embodiment, due to the addition of cyan, the color reproducibility is about 3% better than that of the comparative example without the addition of cyan.

[0130] In addition, as shown in Table 1, compared to the comparative example, the embodiment reduces the cell reflectance by 2.6%. Therefore, the transmittance of the transmission controllable film (OTF) for preventing reflection can be increased, thereby improving the brightness.

[0131] Table 1

[0132]

[0133] Figure 10 shows in the above Figure 8 In the structure, while the ratio of the first thickness t21 of the first sub-color filter 811 to the second thickness t22 of the second sub-color filter 812 is maintained at 1:1, the following Table 2 shows the results of the change in color reproducibility caused by changing the ratio of the area of the first sub-light-emitting region EA11 to the area of the second sub-light-emitting region EA2.

[0134] As Figure 10 shown in [reference] and Table 2, it can be seen that even when the ratio of the area of the first sub-light-emitting region EA11 to the area of the second sub-light-emitting region EA2 is changed, the color reproducibility does not change. Therefore, when the ratio of the first thickness t21 of the first sub-color filter 811 to the second thickness t22 of the second sub-color filter 812 is set to 1:1, it can be seen that it is difficult to improve the color reproducibility.

[0135] Table 2

[0136]

[0137] Figure 11 shows in the above Figure 8In the structure, while the ratio of the first thickness t21 of the first sub-color filter 811 to the second thickness t22 of the second sub-color filter 812 is maintained at 2:1, the following Table 3 shows the results of the change in color reproducibility caused by changing the ratio of the area of the first sub-light-emitting region EA11 to the area of the second sub-light-emitting region EA12.

[0138] As Figure 11 shown in and Table 3, it can be seen that when the area of the first sub-light-emitting region EA11 is larger than the area of the second sub-light-emitting region EA12, the color reproducibility is improved.

[0139] In particular, when the ratio of the area of the first sub-light-emitting region EA11 to the area of the second sub-light-emitting region EA12 is in the range of 7:3 to 9:1, the color reproducibility is excellent, at 87% or more.

[0140] In addition, referring to Figure 11 the color coordinates, it can be seen that when the ratio of the area of the first sub-light-emitting region EA11 to the area of the second sub-light-emitting region EA12 is 8.5:1.5, the best cyan can be achieved.

[0141] Table 3

[0142]

[0143] The following Table 4 shows the change in color reproducibility caused by changing the ratio of the first thickness t21 of the first sub-color filter 811 to the second thickness t22 of the second sub-color filter 812 while the ratio of the area of the first sub-light-emitting region EA11 to the area of the second sub-light-emitting region EA12 is maintained at 8.5:1.5 in the above Figure 8 structure.

[0144] As shown in Table 4, when the first thickness t21 of the green (G) first sub-color filter 811 is thicker than the second thickness t22 of the blue (B) second sub-color filter 812, the color reproducibility is improved compared to the opposite case.

[0145] In particular, when the second thickness t22 of the blue (B) second sub-color filter 812 is maintained at 100%, if the first thickness t21 of the green (G) first sub-color filter 811 is in the range of 180% to 200%, the color reproducibility is excellent, at 87% or greater. In addition, when the first thickness t21 of the green (G) first sub-color filter 811 is maintained at 200%, if the second thickness t22 of the blue (B) second sub-color filter 812 is in the range of 100% to 200%, the color reproducibility is excellent, at 87.4% or greater. Here, when the thicknesses of the first sub-color filter 811 and the second sub-color filter 812 are 100%, it means that the thicknesses of the first sub-color filter 811 and the second sub-color filter 812 are the same as those of Figure 8 the second color filter 820.

[0146] Therefore, in order to obtain a value of color reproducibility of 87% or greater, the first thickness t21 of the first sub-color filter 811 can be formed to be 1.8 times to 2.0 times the thickness of the second color filter 820, and the second thickness t22 of the second sub-color filter 812 can be formed to be 1.0 times to 2.0 times the thickness of the second color filter 820.

[0147] As described above, when the first thickness t21 of the green (G) first sub-color filter 811 is maintained at 200% and the second thickness t22 of the blue (B) second sub-color filter 812 is in the range of 100% to 200%, the color reproducibility can be the same. Considering this, in terms of reducing material costs, etc., the second thickness t22 of the second sub-color filter 812 can preferably be formed to be 100%, that is, formed to be the same as the thickness of the second color filter 820.

[0148] Table 4

[0149]

[0150] Figure 12A shows the spectrum of each wavelength when applying the first electrode 520 having a three-layer structure as shown in Figure 7 , Figure 12B shows the spectrum of each wavelength when applying the first electrode 510 having a five-layer structure as shown in Figure 6 and applying only the first sub-metal layer 514a having a relatively high deposition rate as the second metal layers 514a, 514b, Figure 12C shows the spectrum of each wavelength when applying the first electrode 510 having a five-layer structure as shown in Figure 6 and applying only the second sub-metal layer 514b having a relatively low deposition rate as the second metal layers 514a, 514b.

[0151] Compared withFigure 12A In the case of Figure 12B and Figure 12C the case shows a slightly reduced luminous intensity because the reflectivity of the first electrode 510 applied to Figure 12B and Figure 12C is lower than the reflectivity of the first electrode 520 applied to Figure 12A .

[0152] On the other hand, in the case of Figure 12B and Figure 12C it can be seen that the full width at half maximum (FWHM) of the light has a smaller value compared to Figure 12A . Therefore, compared to the case of Figure 12A in the case of Figure 12B and Figure 12C the color reproducibility can be improved.

[0153] Figure 13A shows the spectrum of applying a green color filter to the spectrum of Figure 12A , Figure 13B shows the spectrum of applying a green color filter to the spectrum of Figure 12B , Figure 13C shows the spectrum of applying a green color filter to the spectrum of Figure 12C .

[0154] In the case of Figure 13A the FWHM of the light in the green wavelength band is 29 nm, in the case of Figure 13B the FWHM of the light in the green wavelength band is 27 nm, in the case of Figure 13C the FWHM of the light in the green wavelength band is 28 nm. Therefore, since the FWHM of the light in the green wavelength band is smaller in the case of Figure 13A compared to the case of Figure 13B and Figure 13C the color reproducibility can be improved in the case of Figure 13B and Figure 13C . In addition, since the FWHM of the light in the green wavelength band is smaller in the case of Figure 13C compared to the case of Figure 13B the color reproducibility can be improved in the case of Figure 13C compared to the case of Figure 13B .

[0155] Figure 14A shows the spectrum of applying a blue color filter to the spectrum of Figure 12A , Figure 14B shows the spectrum of applying a blue color filter to the spectrum of Figure 12B , Figure 14C shows the spectrum of applying a blue color filter to the spectrum of Figure 12C . ​​​​

[0156] In Figure 14A , the FWHM of the light in the blue wavelength band is 24 nm. In Figure 14B , the FWHM of the light in the blue wavelength band is 24 nm. In Figure 14C , the FWHM of the light in the blue wavelength band is 23 nm. Therefore, it can be seen that, since the FWHM of the light in the blue wavelength band is smaller in the case of Figure 14A than in the case of Figure 14C , the color reproducibility can be improved in the case of Figure 14A compared to the case of Figure 14C . In addition, it can be seen that, since the FWHM of the light in the blue wavelength band is smaller in the case of Figure 14B than in the case of Figure 14C , the color reproducibility can be improved in the case of Figure 14B compared to the case of Figure 14C .

[0157] From the above results, it can be seen that the color reproducibility can be improved in the case of applying the first electrode 510 having a five-layer structure as shown in Figure 7 compared to the case of applying the first electrode 520 having a three-layer structure as shown in Figure 6 .

[0158] In addition, according to the results of Figure 13B and Figure 13C and the results of Figure 14B and Figure 14C , it is desirable that the first sub-metal layer 514a having a relatively high deposition rate corresponds to the first sub-light-emitting region EA11 and the second sub-metal layer 514b having a relatively low deposition rate corresponds to the second sub-light-emitting region EA12.

[0159] Figures 15A to 15E is a chart showing various optical characteristics of the first sub-metal layer 514a having a relatively high deposition rate and the second sub-metal layer 514b having a relatively low deposition rate.

[0160] Specifically, Figure 15A is a chart showing the change in the refractive index n of each wavelength band, Figure 15B is a chart showing the change in the extinction coefficient k of each wavelength band, Figure 15C is a chart showing the change in the reflectance of each wavelength band, Figure 15D is a chart showing the change in the transmittance of each wavelength band, Figure 15E is a chart showing the change in the absorbance of each wavelength band. The results based on Figures 15A to 15E are shown in Table 5 below.

[0161] As Figure 15A and shown in Table 5, from the short wavelength band to the long wavelength band, the refractive index n of the first sub-metal layer 514a of and the refractive index n of the second sub-metal layer 514b of both increase. In addition, it can be seen that from the short wavelength band to the long wavelength band, the refractive index n of the second sub-metal layer 514b of

[0162] As Figure 15B and shown in Table 5, it can be seen that from the short wavelength band to the long wavelength band, the refractive index k of the first sub-metal layer 514a of increases, but the refractive index k of the second sub-metal layer 514b of

[0163] In addition, at the short wavelength (450 nm), the refractive index k of the second sub-metal layer 514b of is higher than the refractive index k of the first sub-metal layer 514a of However, at the medium wavelength (550 nm) and the long wavelength (650 nm), the refractive index k of the second sub-metal layer 514b of

[0164] As Figure 15C and shown in Table 5, it can be seen that from the short wavelength band to the long wavelength band, the reflectivity of the first sub-metal layer 514a of slightly increases and then decreases, but the reflectivity of the second sub-metal layer 514b of

[0165] In addition, at the short wavelength (450 nm), the reflectivity of the second sub-metal layer 514b of is higher than the reflectivity of the first sub-metal layer 514a of However, at the medium wavelength (550 nm) and the long wavelength (650 nm), the reflectivity of the second sub-metal layer 514b of is 20.9%, and the reflectivity of the first sub-metal layer 514a of is 22.6%.

[0166] As Figure 15D and shown in Table 5, it can be seen that from the short wavelength band to the long wavelength band, the transmittance of the first sub-metal layer 514a of The transmittance of the second sub-metal layer 514b increases.

[0167] In addition, in the short wavelength (450 nm) and medium wavelength (550 nm), the transmittance of the second sub-metal layer 514b is lower than that of the first sub-metal layer 514a, but in the wavelength band of 700 nm or greater, the transmittance of the second sub-metal layer 514b is higher than that of the first sub-metal layer 514a. On average, the transmittance of the second sub-metal layer 514b is 24.7%, and the transmittance of the first sub-metal layer 514a is 29.9%.

[0168] From Figure 15E and Table 5, it can be seen that from the short wavelength band to the long wavelength band, the absorption rate of the first sub-metal layer 514a increases slightly, but the absorption rate of the second sub-metal layer 514b is almost constant.

[0169] In addition, it can be seen that from the short wavelength band to the long wavelength band, the absorption rate of the second sub-metal layer 514b is higher than that of the first sub-metal layer 514a. On average, the absorption rate of the second sub-metal layer 514b is 54.4%, and the absorption rate of the first sub-metal layer 514a is 47.4%.

[0170] Table 5

[0171]

[0172] The following Table 6 shows the changes in the refractive index n and refractive index k of each wavelength band based on the deposition rate of the first sub-metal layer 514a.

[0173] As shown in Table 6, when the deposition rate of the first sub-metal layer 514a is in the range of to from the short wavelength band (450 nm) to the long wavelength band (650 nm), both the refractive index n and the refractive index k increase.

[0174] In addition, it can be seen that when the deposition rate of the first sub-metal layer 514a increases from to the refractive index n gradually decreases and the refractive index k gradually increases.

[0175] When the deposition rate of the first sub-metal layer 514a is in the range of to When in the range from to , it can be seen that the refractive index n of the short wavelength band (450 nm) is in the range from 2.055 to 1.758, the refractive index n of the middle wavelength band (550 nm) is in the range from 2.377 to 2.072, and the refractive index n of the long wavelength band (650 nm) is in the range from 2.690 to 2.389. In particular, when the deposition rate of the first sub-metal layer 514a changes from increases to , it can be seen that the refractive index n of the short wavelength band (450 nm) decreases from 2.055 to 1.758, the refractive index n of the middle wavelength band (550 nm) decreases from 2.377 to 2.072, and the refractive index n of the long wavelength band (650 nm) decreases from 2.690 to 2.389.

[0176] When the deposition rate of the first sub-metal layer 514a is in the range from to , it can be seen that the refractive index k of the short wavelength band (450 nm) is in the range from 3.150 to 3.379, the refractive index k of the middle wavelength band (550 nm) is in the range from 3.400 to 3.793, and the refractive index k of the long wavelength band (650 nm) is in the range from 3.650 to 4.125. In particular, when the deposition rate of the first sub-metal layer 514a changes from increases to , it can be seen that the refractive index k of the short wavelength band (450 nm) increases from 3.150 to 3.379, the refractive index k of the middle wavelength band (550 nm) increases from 3.400 to 3.793, and the refractive index k of the long wavelength band (650 nm) increases from 3.650 to 4.125.

[0177] As described above, as the deposition rate changes, the refractive index of the first sub-metal layer 514a changes in each wavelength band, and when the deposition rate of the first sub-metal layer 514a is in the range from to , it has a refractive index within an appropriate range, thus enabling the above-described low reflection characteristics and color reproducibility characteristics.

[0178] Table 6

[0179]

[0180] Table 7 below shows the changes in the refractive index n and the refractive index k in each wavelength band based on the change in the deposition rate of the second sub-metal layer 514b.

[0181] As shown in Table 7, when the deposition rate of the second sub-metal layer 514b is in the range from to When within the range of, from the short wavelength band (450 nm) to the long wavelength band (650 nm), the refractive index n increases and the refractive index k decreases.

[0182] In addition, it can be seen that when the deposition rate of the second sub-metal layer 514b changes from increases to , the refractive index n gradually decreases in the entire wavelength band. On the other hand, the refractive index k gradually decreases in the short wavelength band (450 nm) and the medium wavelength band (550 nm), but gradually increases in the long wavelength band (650 nm).

[0183] When the deposition rate of the second sub-metal layer 514b is within the range of to , it can be seen that the refractive index n of the short wavelength band (450 nm) is within the range of 3.128 to 2.820, the refractive index n of the medium wavelength band (550 nm) is within the range of 3.416 to 3.122, and the refractive index n of the long wavelength band (650 nm) is within the range of 3.551 to 3.318. In particular, when the deposition rate of the second sub-metal layer 514b changes from increases to , it can be seen that the refractive index n of the short wavelength band (450 nm) decreases from 3.128 to 2.820, the refractive index n of the medium wavelength band (550 nm) decreases from 3.416 to 3.122, and the refractive index n of the long wavelength band (650 nm) decreases from 3.551 to 3.318.

[0184] When the deposition rate of the second sub-metal layer 514b is within the range of to , it can be seen that the refractive index k of the short wavelength band (450 nm) is within the range of 3.453 to 3.299, the refractive index k of the medium wavelength band (550 nm) is within the range of 3.216 to 3.195, and the refractive index k of the long wavelength band (650 nm) is within the range of 3.076 to 3.173. In particular, when the deposition rate of the second sub-metal layer 514b changes from increases to , it can be seen that the refractive index k of the short wavelength band (450 nm) decreases from 3.453 to 3.299, the refractive index k of the medium wavelength band (550 nm) decreases from 3.216 to 3.195, and the refractive index k of the long wavelength band (650 nm) increases from 3.076 to 3.173.

[0185] As described above, as the deposition rate changes, the refractive index of the second sub-metal layer 514b changes in each wavelength band, and when the deposition rate of the second sub-metal layer 514b is within the range of to When within the range, it has an appropriate refractive index range, thereby enabling the realization of the above-mentioned low reflection characteristics and color reproducibility characteristics.

[0186] Table 7

[0187]

[0188] That is to say, the refractive index n of the first sub-metal layer 514a can be different from the refractive index n of the second sub-metal layer 514b. In the entire wavelength band, the refractive index n of the first sub-metal layer 514a can be lower than the refractive index n of the second sub-metal layer 514b.

[0189] According to the present invention, the following effects are achieved.

[0190] According to an embodiment of the present invention, color reproducibility can be improved by including a sub-pixel that emits cyan light.

[0191] According to an embodiment of the present invention, the sub-pixel that emits cyan light includes a first sub-light emitting region that emits green light and a second sub-light emitting region that emits blue light, such that a desired cyan light can be obtained by adjusting the area ratio of the first sub-light emitting region and the second sub-light emitting region.

[0192] According to an embodiment of the present invention, the sub-pixel that emits cyan light includes a first sub-light emitting region that emits green light and a second sub-light emitting region that emits blue light, such that a desired cyan light can be obtained by adjusting the thickness ratio of the green color filter provided in the first sub-light emitting region and the blue color filter provided in the second sub-light emitting region.

[0193] According to an embodiment of the present invention, by including a low reflection electrode in the sub-pixel that emits cyan light, the transmittance of the transmissive controllable film (OTF) for antireflection can be increased, thereby increasing the brightness.

[0194] According to an embodiment of the present invention, by including a first sub-metal layer corresponding to the first sub-light emitting region formed at a relatively high deposition rate and a second sub-metal layer corresponding to the second sub-light emitting region formed at a relatively low deposition rate in the sub-pixel that emits cyan light, the FWHM (full width at half maximum) of green light and blue light is reduced, thereby improving color reproducibility.

[0195] As a result, according to an embodiment of the present invention, a low-power electroluminescent display device with high efficiency, low reflection, and high color reproducibility can be realized.

[0196] Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the technical idea of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but for illustration, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the above embodiments are exemplary in all aspects and not restrictive. The protection scope of the present invention should be interpreted by the claims, and all technical ideas within the equivalent scope should be interpreted as being included within the scope of the present invention.

Claims

1. An electroluminescent display device, comprising: A first sub-pixel including a first light emitting region; a first electrode disposed in the first sub-pixel; a light-emitting layer disposed on the first electrode; a second electrode disposed on the light-emitting layer; an encapsulation layer disposed on the second electrode; and a cyan color filter disposed on the encapsulation layer, The first light-emitting region includes a first sub-light-emitting region and a second sub-light-emitting region, The cyan color filter includes a first sub-color filter corresponding to the first sub-light emitting area and a second sub-color filter corresponding to the second sub-light emitting area, and The first sub-color filter transmits green light, and the second sub-color filter transmits blue light. 2 . The electroluminescent display device according to claim 1 , wherein an area of ​​the first sub-light emitting region is larger than an area of ​​the second sub-light emitting region. 3 . The electroluminescent display device according to claim 2 , wherein a ratio of an area of ​​the first sub-light emitting region to an area of ​​the second sub-light emitting region is in a range of 7:3 to 9:

1. 4 . The electroluminescent display device according to claim 1 , wherein a thickness of the first sub-color filter is thicker than a thickness of the second sub-color filter. 5 . The electroluminescent display device according to claim 4 , wherein a ratio of a thickness of the first sub-color filter to a thickness of the second sub-color filter is in a range of 1.8:1 to 2:

1. 6 . The electroluminescent display device according to claim 4 , wherein a lower surface of the first sub-color filter is located closer to the second electrode than a lower surface of the second sub-color filter. 7 . The electroluminescent display device according to claim 4 , wherein an upper surface of the first sub-color filter and an upper surface of the second sub-color filter are formed at the same height. 8 . The electroluminescent display device according to claim 1 , wherein the first sub-color filter and the second sub-color filter contact each other at a boundary between the first sub-light emitting area and the second sub-light emitting area.

9. The electroluminescent display device according to claim 1, wherein the second sub-light emitting area has a stripe structure, and The first sub-light emitting region is disposed at one side of the second sub-light emitting region or includes two regions spaced apart from each other via the second sub-light emitting region. 10 . The electroluminescent display device according to claim 1 , wherein the first sub-light emitting region surrounds the entire periphery of the second sub-light emitting region.

11. The electroluminescent display device according to claim 1, wherein the first electrode comprises a first sub-metal layer corresponding to the first sub-light emitting region and a second sub-metal layer corresponding to the second sub-light emitting region, and The refractive index n of the first sub-metal layer is different from the refractive index n of the second sub-metal layer.

12. The electroluminescent display device according to claim 11, wherein the first sub-metal layer and the second sub-metal layer are made of the same material, and The deposition rate of the first sub-metal layer is higher than the deposition rate of the second sub-metal layer.

13. The electroluminescent display device according to claim 12, wherein the deposition rate of the first sub-metal layer is arrive and the deposition rate of the second sub-metal layer is arrive within the range. 14 . The electroluminescent display device according to claim 11 , wherein a refractive index n of the first sub-metal layer is lower than a refractive index n of the second sub-metal layer in the entire wavelength band.

15. The electroluminescent display device according to claim 11, wherein the refractive index n of the first sub-metal layer in the 450 nm wavelength band is in the range of 1.758 to 2.055, and the refractive index n of the first sub-metal layer in the 550 nm wavelength band is in the range of 2.072 to 2.377, The refractive index n of the second sub-metal layer in the 450 nm wavelength band is in the range of 2.820 to 3.128, and the refractive index n of the second sub-metal layer in the 550 nm wavelength band is in the range of 3.122 to 3.

416.

16. The electroluminescent display device according to claim 11, wherein the first electrode further comprises: a first transparent conductive layer; a first metal layer disposed on the first transparent conductive layer; a second transparent conductive layer disposed on the first metal layer; and a third transparent conductive layer disposed on the second transparent conductive layer, The first sub-metal layer and the second sub-metal layer are arranged between the second transparent conductive layer and the third transparent conductive layer. 17 . The electroluminescent display device according to claim 11 , wherein the first sub-metal layer and the second sub-metal layer contact each other at a boundary between the first sub-light emitting region and the second sub-light emitting region.

18. An electroluminescent display device, comprising: a plurality of sub-pixels, the plurality of sub-pixels comprising a first sub-pixel having a first light emitting region and a second sub-pixel having a second light emitting region; a first electrode disposed in each of the first sub-pixel and the second sub-pixel; a light-emitting layer disposed on the first electrode; a second electrode disposed on the light-emitting layer; and a plurality of color filters, the plurality of color filters including a first color filter corresponding to the first light emitting area and a second color filter corresponding to the second light emitting area, The first light-emitting region includes a first sub-light-emitting region and a second sub-light-emitting region, the first sub-light-emitting region and the second sub-light-emitting region emit light of different colors, and The first color filter includes a first sub-color filter corresponding to the first sub-light emitting area and a second sub-color filter corresponding to the second sub-light emitting area.

19. The electroluminescent display device according to claim 18, wherein the first sub-pixel emits cyan light, the second sub-pixel emits any one of red light, green light and blue light, and The first sub-color filter includes a green color filter, and the second sub-color filter includes a blue color filter. 20 . The electroluminescent display device according to claim 18 , wherein an area of ​​the first sub-light emitting region is greater than an area of ​​the second sub-light emitting region.

21. The electroluminescent display device according to claim 18, wherein a thickness of the first sub-color filter is thicker than a thickness of the second sub-color filter. 22 . The electroluminescent display device according to claim 21 , wherein a thickness of the second color filter is thinner than a thickness of the first sub-color filter and is equal to or smaller than a thickness of the second sub-color filter. 23 . The electroluminescent display device according to claim 18 , wherein a thickness of the first electrode of the first sub-pixel is thicker than a thickness of the first electrode of the second sub-pixel.

24. The electroluminescent display device according to claim 18, wherein the first electrode of the first sub-pixel comprises a first sub-metal layer corresponding to the first sub-light emitting region and a second sub-metal layer corresponding to the second sub-light emitting region, The first sub-metal layer and the second sub-metal layer are made of the same material, and The refractive index of the first sub-metal layer is different from the refractive index of the second sub-metal layer. 25 . The electroluminescent display device according to claim 18 , wherein a reflectivity of the first electrode of the first subpixel is lower than a reflectivity of the first electrode of the second subpixel.

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