KR20220053290A - Electroluminescent Display - Google Patents

Abstract

The present application relates to an electroluminescent display minimizing external light reflection. The electroluminescent display device according to the present application includes a first sub-pixel, a second sub-pixel, and an optical guide. The first sub-pixel includes a first color filter. The second sub-pixel is disposed adjacent to the first sub-pixel and includes a lens layer, a first transparent electrode, a first light-emitting layer, a reflective electrode, a second light-emitting layer, and a second transparent electrode sequentially stacked. The optical guide is disposed in a lower space of the first sub-pixel and the second sub-pixel. The optical guide has a wedge shape having top portions contacting each other at a boundary between the first sub-pixel and the second sub-pixel, and an upper surface corresponding to the area of the first sub-pixel and the second sub-pixel.

Description

Electroluminescent Display {Electroluminescent Display}

This application relates to an electroluminescent display device. In particular, this application relates to an electroluminescent display device that minimizes external light reflection without a separate optical film.

As the information society develops, the demand for a display device for displaying an image is increasing in various forms. A device for displaying an image has been developed and developed in various forms, such as a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display panel (PDP), and an electroluminescent display (Luminescent Display). In particular, the electroluminescent display device may include a self-emission display device or a curved self-luminescence display device. For example, the display device may include a light emitting display panel, a micro light emitting diode display panel, a flexible light emitting display panel, a flexible micro light emitting diode display panel, or a quantum dot light emitting display panel, but is not limited thereto.

Among the display devices, the electroluminescent display device is a self-luminous display device, and has superior viewing angle and contrast ratio compared to a liquid crystal display device, and it does not require a separate backlight, so it can be lightweight and thin, and has advantageous power consumption. In addition, the organic light emitting display device, which is a type of the electroluminescent display device, can be driven at a low DC voltage, has a fast response speed, and has the advantages of low manufacturing cost.

In the case of an electroluminescent display device, an optical film such as a polarizing plate is used to prevent external light from being reflected and deteriorated in display quality. In this case, the amount of light provided by the electroluminescent display device may be reduced by at least 50% or more by the polarizing plate. As a result, more power is required for desired luminance.

Accordingly, there is an increasing demand for an improved electroluminescent display device that suppresses reflection of external light and provides brighter luminance or uses less power consumption even with the same luminance.

An object of this application is to overcome the problems of the prior art, and to provide an electroluminescent display device that provides high-quality image information by suppressing external light reflection without an optical element such as a polarizing plate. Another object of the present application is to provide an electroluminescent display device that does not include an optical element for suppressing external light reflection, thereby preventing loss of the amount of light provided by self-emission and providing high-quality image information. Another object of the present application is to provide an electroluminescent display device that suppresses reflection of external light without an optical element and provides high luminance with low power consumption.

In order to achieve the object of this application, the electroluminescent display device according to this application includes a first sub-pixel, a second sub-pixel, and a light guide. The first sub-pixel includes a first color filter. The second sub-pixel is disposed adjacent to the first sub-pixel and includes a lens layer, a first transparent electrode, a first light-emitting layer, a reflective electrode, a second light-emitting layer, and a second transparent electrode that are sequentially stacked. The light guide is disposed in a space below the first sub-pixel and the second sub-pixel. The light guide has a wedge shape having a vertex that abuts against each other at a boundary between the first sub-pixel and the second sub-pixel, and an upper surface corresponding to the area of the first sub-pixel and the second sub-pixel.

For example, the first light-emitting layer includes a yellow light-emitting material. The second light emitting layer includes a blue light emitting material.

For example, the first light emitting layer is driven by the voltage difference between the first transparent electrode and the reflective electrode. The light emitted from the first light emitting layer is emitted upwardly of the first sub-pixel through the light guide unit.

For example, the second light emitting layer is driven by the voltage difference between the reflective electrode and the second transparent electrode. The light emitted from the second light emitting layer is emitted in an upper direction of the second sub-pixel.

For example, in the first sub-pixel, a first driving thin film transistor connected to the first transparent electrode is disposed. A second driving thin film transistor connected to the reflective electrode is disposed in the second sub-pixel. The second transparent electrode is connected to the common power terminal.

For example, in the first sub-pixel, a first driving thin film transistor connected to the first transparent electrode is disposed. A second driving thin film transistor connected to the second transparent electrode is disposed in the second sub-pixel. The reflective electrode is connected to the common power supply terminal.

For example, the light guide unit includes a first inclined surface, a second inclined surface, a first reflective layer, a second reflective layer, and a light absorbing layer. The first inclined surface is disposed below the first sub-pixel. The second inclined surface is disposed below the second sub-pixel. The first reflective layer is disposed on the entire surface of the first inclined surface. The second reflective layer is disposed at a focal position of the lens layer on the second inclined surface. The light absorbing layer is disposed on the separated portion of the second inclined surface except for the second reflective layer.

For example, the light emitted from the first light emitting layer is condensed to the second reflective layer by the lens layer, is reflected by the first reflective layer, and exits in the upper direction of the first sub-pixel through the first color filter in the first reflective layer . The light emitted from the second emission layer is reflected by the reflective electrode and exits toward the upper direction of the second sub-pixel through the second transparent electrode.

For example, external light incident through the first color filter is reflected by the first reflective layer and transmitted to the second inclined surface, most of the light reaching the light absorbing layer is extinguished, and only the light incident on the second reflective layer is transmitted to the lens layer through the reflective electrode.

For example, a predetermined amount of external light incident on the reflective electrode is absorbed by the reflective electrode, and only a small amount of the remaining light is sequentially reflected by the second reflective layer and the first reflective layer, and is emitted upward of the first sub-pixel.

For example, among the incident external light, the ratio of the light reflected in the upper direction of the first sub-pixel is 10% or less.

For example, the ratio of the area of the first sub-pixel to the area of the second sub-pixel is any one selected from 1:1 to 2:1.

For example, the electroluminescent display device further includes a third sub-pixel and a fourth sub-pixel. The third sub-pixel is adjacent to the second sub-pixel and disposed to face the first sub-pixel. The fourth sub-pixel is adjacent to the third sub-pixel and disposed to face the second sub-pixel. The third sub-pixel includes a second color filter. The fourth sub-pixel has the same structure as the third sub-pixel.

For example, the first to fourth sub-pixels form one unit pixel. The first color filter includes a red color filter. The second color filter includes a green color filter. The second emission layer disposed in each of the second sub-pixel and the fourth sub-pixel includes a blue light-emitting material.

For example, the ratio of the area of the first sub-pixel, the area of the second sub-pixel, the area of the third sub-pixel, and the area of the fourth sub-pixel may be any selected from 1:1:1:1 to 2:1:2:1. one

The electroluminescent display according to this application has a feature of minimizing the reflection of external light only structurally without an optical element such as a polarizing plate. In addition, since there is no optical element, reflection of external light is minimized and the amount of light emitted from the light emitting element is not reduced. Therefore, in realizing the same brightness, it can be implemented with low power consumption. Also, it is possible to provide high-quality image information with higher luminance under the same power consumption situation. The electroluminescent display device according to the present application provides high-quality image information with low power consumption, and does not cause a problem of display quality degradation due to external light reflection.

1 is a plan view illustrating an example of a display panel constituting an electroluminescent display according to this application.
2 is a plan view showing the structure of a unit pixel constituting the electroluminescence display according to the first embodiment of the present application.
3 is a plan view illustrating the structure of a pair of sub-pixels constituting the electroluminescence display according to the first embodiment of the present application.
4 is a cross-sectional view showing the structure of the electroluminescent display device according to the first embodiment of the present application, taken along the cut line I-I' of FIG. 3 .
5A is a perspective view illustrating a structure of a light guide disposed in a pair of sub-pixels constituting an electroluminescent display device according to a first embodiment of the present application.
5B is a cross-sectional view illustrating a cross-sectional structure of the light guide according to the first embodiment of the present application and an optical path during light emission.
5C is a cross-sectional view illustrating a cross-sectional structure of a light guide and an optical path of external light according to the first embodiment of the present application.
6 is a diagram illustrating a method of driving a sub-pixel of the electroluminescence display according to the first embodiment.
7 is a cross-sectional view showing the structure of the electroluminescent display device according to the second embodiment of the present application, taken along the cut line I-I' of FIG. 3 .
8 is a diagram illustrating a method of driving a sub-pixel of an electroluminescence display according to a second embodiment.
9 is a plan view illustrating an area ratio of sub-pixels constituting a unit pixel in an electroluminescence display according to an embodiment of the present application.
10 is a plan view illustrating an area ratio of sub-pixels constituting a unit pixel in an electroluminescent display device according to another embodiment of the present application.

Advantages and features of this application, and a method of achieving them, will become apparent with reference to examples described below in detail in conjunction with the accompanying drawings. However, this application is not limited to the examples disclosed below, but will be implemented in various different forms, and only examples of this application allow the disclosure of this application to be complete, and it is common in the technical field to which the invention of this application belongs. It is provided to fully inform those with knowledge of the scope of the invention, and the invention of this application is only defined by the scope of the claims.

The shape, size, ratio, angle, number, etc. disclosed in the drawings for explaining an example of this application are exemplary, and thus are not limited to the matters shown here. Like reference numerals refer to like elements throughout. In addition, in explaining the example of this application, if it is determined that the detailed description of the related known technology may unnecessarily obscure the gist of the application, the detailed description thereof will be omitted.

When 'including', 'having', 'consisting', etc. mentioned in this application specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, cases including the plural are included unless otherwise explicitly stated.

In interpreting the components, it is construed as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between two parts unless 'directly' is used.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal relationship is described with 'after', 'following', 'after', 'before', etc. It may include cases that are not continuous unless this is used.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the technical spirit of this application.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, the meaning of “at least one of the first, second, and third items” means that each of the first, second, or third items as well as two of the first, second and third items It may mean a combination of all items that can be presented from more than one.

Each feature of the various examples of this application may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each example may be implemented independently of each other or may be implemented together in a related relationship. .

Hereinafter, various structures of the electroluminescent display device according to the present application will be described in detail with reference to the accompanying drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings.

First, a flat panel display device according to this application will be described with reference to FIG. 1 . 1 is a plan view illustrating an example of a display panel constituting an electroluminescent display according to this application.

The display panel DIP may be selected from various display panels such as a liquid crystal display panel, a plasma display panel, and an electroluminescence display panel. In particular, when an electroluminescent display panel is applied, the display panel DIP may include a self-luminous display panel or a curved self-luminous display panel. Specifically, the display panel DIP may include a light emitting display panel, a micro light emitting diode display panel, a flexible light emitting display panel, a flexible micro light emitting diode display panel, or a quantum dot light emitting display panel.

The display panel DIP includes a substrate SUB, a gate (or scan) driver 20 , a data pad unit 30 , a source driving integrated circuit 41 , a flexible film 43 , a circuit board 45 , and a timing. a control unit 50 .

The substrate SUB of the display panel DIP may be formed of a transparent material or an opaque material. In the case of the bottom emission type, since light emitted from the display element passes through the substrate SUB and exits, the substrate SUB is preferably made of a transparent material. In the case of the top emission type, since light emitted from the display element is emitted upward from the upper surface of the substrate SUB, it may be formed of an opaque material.

The substrate SUB may be divided into a display area DA and a non-display area NDA. The display area DA is an area in which an image is displayed and may be defined in most areas including the central portion of the substrate SUB, but is not limited thereto. A plurality of pixel areas P may be arranged in a matrix manner in the display area DA. The pixel regions P may have a rectangular shape surrounded by scan lines (or gate lines) SL, data lines DL, and driving current lines VDD. A switching thin film transistor ST, a driving thin film transistor DT, a storage capacitor Cst, and an organic light emitting diode OLED may be disposed in the pixel region P.

A plurality of pixels P may be arranged in a matrix manner on the substrate SUB. In addition, one light emitting area EA is defined in one pixel P. In an area of one pixel P except for the emission area EA, the switching thin film transistor ST, the driving thin film transistor DT, the storage capacitor Cst, the scan wiring SL, the data wiring DL, and the driving current wiring (VDDs) may be deployed. For example, an organic light emitting diode OLED connected to the driving thin film transistor DT may be disposed in the light emitting area EA.

The light emitting area EA may display one color. For example, any one of red, green, and blue colors may be displayed. Three pixels P in which light emitting areas EA representing red, green, and blue are disposed may be gathered to form one unit pixel. Although not illustrated, as another example, the light emitting area EA may display any one of four colors such as red, green, blue, and white. In this case, four pixels P may be gathered to form one unit pixel.

One pixel P having the emission area EA representing one color may be defined as a sub-pixel. In FIG. 1 , a pixel P may correspond to a sub-pixel, and shows a structure in which the sub-pixels are arranged in a matrix manner.

A black matrix (not shown) may be disposed between each pixel P. The black matrix may be disposed in an area of the pixel P except for the emission area EA. In some cases, the black matrix may be disposed to overlap the switching thin film transistor ST, the driving thin film transistor DT, the scan lines SL, the data lines DL, and the driving current lines VDD. As another example, the switching thin film transistor ST, the driving thin film transistor DT, and the storage capacitor Cst may be disposed to overlap the light emitting area EA.

FIG. 1 illustrates a structure of a bottom emission type in which the emission area EA is disposed so as not to overlap the thin film transistors DT and ST in the pixel P. Referring to FIG. Although not shown in the drawings, in the case of the top emission type, the emission area EA may be disposed to overlap a portion of the thin film transistors DT and ST, the storage capacitor Cst, and the wirings SL, DL, and VDD.

The non-display area NDA is an area in which an image is not displayed, and may be defined at an edge portion of the substrate SUB to surround all or a part of the display area DA. The gate driver 20 and the data pad part 30 may be formed in the non-display area NDA.

The gate driver 20 supplies scan (or gate) signals to the scan lines according to a gate control signal input from the timing controller 50 . The gate driver 20 may be formed in the non-display area NDA outside the display area DA of the substrate SUB using a gate driver in panel (GIP) method. The GIP method refers to a structure in which the gate driver 20 including a thin film transistor and a capacitor is directly formed on a substrate SUB.

The data pad unit 30 supplies data signals to data lines according to a data control signal input from the timing control unit 50 . The data pad unit 30 is manufactured as a driving chip, mounted on the flexible film 43 , and placed on the non-display area NDA on one side of the display area DA of the substrate 110 in a tape automated bonding (TAB) method. can be attached.

The source driving integrated circuit 41 receives digital video data and a source control signal from the timing controller 50 . The source driving integrated circuit 41 converts digital video data into analog data voltages according to a source control signal and supplies them to data lines. When the source driving integrated circuit 41 is manufactured as a chip, it may be mounted on the flexible film 43 using a chip on film (COF) or chip on plastic (COP) method.

Wires connecting the data pad unit 30 and the source driving integrated circuit 41 and wirings connecting the data pad unit 30 and the circuit board 45 may be formed on the flexible film 43 . The flexible film 43 is attached on the data pad unit 30 using an anisotropic conducting film, whereby wires of the data pad unit 30 and the flexible film 43 may be connected.

The circuit board 45 may be attached to the flexible films 43 . A plurality of circuits implemented with driving chips may be mounted on the circuit board 45 . For example, the timing controller 50 may be mounted on the circuit board 45 . The circuit board 45 may be a printed circuit board or a flexible printed circuit board.

The timing controller 50 receives digital video data and a timing signal from an external system board through a cable of the circuit board 45 . The timing controller 50 generates a gate control signal for controlling the operation timing of the gate driver 20 and a source control signal for controlling the source driving integrated circuits 41 based on the timing signal. The timing controller 50 supplies the gate control signal to the gate driver 20 and supplies the source control signal to the source driving integrated circuits 41 . Depending on the product, the timing controller 50 may be formed of the source driving integrated circuit 41 and one driving chip and mounted on the substrate SUB.

Hereinafter, an arrangement structure of four sub-pixels constituting one unit pixel as a core configuration of this application will be described in detail using a plan view and a cross-sectional view. In particular, the features of the invention according to this application will be described through various embodiments.

Although only one sub-pixel constituting the electroluminescent display is shown in FIG. 1, a plurality of sub-pixels constituting one unit pixel are shown and described in the following drawings. Accordingly, in the following description, features not shown in FIG. 1 will be mainly described, and the same description will be omitted unless necessary.

<First embodiment>

2 and 3, a first embodiment of the present application will be described. 2 is a plan view showing the structure of a unit pixel constituting the electroluminescence display according to the first embodiment of the present application. 3 is a plan view illustrating the structure of a pair of sub-pixels constituting the electroluminescence display according to the first embodiment of the present application.

The electroluminescent display device according to the first embodiment of the present application includes a plurality of unit pixels arranged in a matrix manner. One unit pixel means a unit expressing color and brightness corresponding to one pixel of an image. One unit pixel may include several sub-pixels. For example, when a color is implemented using three primary colors of red, green, and blue, one unit pixel may include a red sub-pixel, a green sub-pixel, and a blue sub-pixel.

In the first embodiment of this application shown in FIG. 2 , one unit pixel UP includes a red sub-pixel SPR, a first blue sub-pixel SPB1, a green sub-pixel SPG, and a second blue sub-pixel. (SPB2) may be provided. In particular, the red sub-pixel SPR and the first blue sub-pixel SPB1 may be disposed adjacent to each other to form a pair. Similarly, the green sub-pixel SPG and the second blue sub-pixel SPB2 may be disposed adjacent to each other to form a pair. Two pairs of sub-pixels are disposed adjacent to each other to configure one unit pixel UP.

The unit pixel UP may include one scan line SL, four data lines DLR, DLB1, DLG, and DLB2, and one driving current line VDD. The scan line SL may run in a horizontal direction, and the four data lines DLR, DLB1, DLG, and DLB2 and the driving current line VDD may run in a vertical direction.

The red sub-pixel SPR includes a scan line SL, a red data line DLR, a red switching thin film transistor STR, a red driving thin film transistor DTR, and a red color filter CFR. In addition, a part of the driving wiring horizontal portion VDH connected to the driving current wiring VDD is disposed. A driving element for driving the light emitting element is disposed in the red sub-pixel SPR, but the light emitting element is not disposed, and a red color filter CFR capable of expressing red light is provided.

The first blue sub-pixel SPB1 includes the scan line SL, the first blue data line DLB1 , the first blue switching thin film transistor STB1 , the first blue driving thin film transistor DTB1 , and the first light emitting diode OL1 . ) is provided. In addition, a part of the driving wiring horizontal portion VDH connected to the driving current wiring VDD is disposed. The first light emitting diode OL1 includes a red light emitting diode OLR and a first blue light emitting diode OLB1. The red light emitting diode OLR and the first blue light emitting diode OLB1 have the same shape and size and have a structure overlapping each other. The detailed structure will be described in detail in the section describing the cross-sectional view.

The green sub-pixel SPG includes a scan line SL, a green data line DLG, a green switching thin film transistor STG, a green driving thin film transistor DTG, and a green color filter CFG. In addition, a part of the driving wiring horizontal portion VDH connected to the driving current wiring VDD is disposed. A driving element for driving the light emitting element is disposed in the green sub-pixel SPG, but the light emitting element is not disposed, and a green color filter CFG capable of expressing green light is provided.

The second blue sub-pixel SPB2 includes the scan line SL, the second blue data line DLB2 , the second blue switching thin film transistor STB2 , the second blue driving thin film transistor DTB2 , and the second light emitting diode OL2 . ) is provided. In addition, a part of the driving wiring horizontal portion VDH connected to the driving current wiring VDD is disposed. The second light emitting diode OL2 includes a green light emitting diode OLG and a second blue light emitting diode OLB2. The green light emitting diode OLG and the second blue light emitting diode OLB2 have the same shape and size and have a structure overlapping each other.

In the electroluminescent display according to this application, the unit pixel UP includes two pairs of sub-pixels. That is, the red sub-pixel SPR and the first blue sub-pixel SPB1 form a pair, and the green sub-pixel SPG and the second blue sub-pixel SPB2 form another pair, and these two pairs are combined to form a single pair. It forms a unit pixel (UP). Hereinafter, a pair of pixel structures constituting the unit pixel of this application will be described in detail with reference to FIG. 3 . For convenience, a cross-sectional structure of a pair including the red sub-pixel SPR and the first blue sub-pixel SPB1 will be described. 3 is a plan view illustrating the structure of a pair of sub-pixels constituting the electroluminescence display according to the first embodiment of the present application.

The red sub-pixel SPR and the first blue sub-pixel SPB1 are disposed adjacent to each other. The scan line SL crosses the red sub-pixel SPR and the first blue sub-pixel SPB1 in a horizontal direction. A red data line DLR runs in a vertical direction on one side of the red sub-pixel SPR. A first blue data line DLB1 runs in a vertical direction on one side of the first blue sub-pixel SPB1 . A driving current line VDD runs in a vertical direction on an outer side of the first blue data line DLB1 . The driving horizontal line VDH is connected to the driving current line VDD and extends in the horizontal direction.

A red switching thin film transistor STR, a red driving thin film transistor DTR, and a red color filter CFR are disposed in the red sub-pixel SPR. The red switching thin film transistor STR includes a red switching gate electrode SGR, a red switching semiconductor layer SAR, a red switching source electrode SSR, and a red switching drain electrode SDR. The red driving thin film transistor DTR includes a red driving gate electrode DGR, a red driving semiconductor layer DAR, a red driving source electrode DSR, and a red driving drain electrode DDR. The red color filter CFR is disposed in an island shape in the red sub-pixel SPR area.

The red switching gate electrode SGR may have a structure branched from the scan line SL or may be defined as a part of the scan line SL. As illustrated in FIG. 3 , the red switching gate electrode SGR may be defined in a portion overlapping the red switching semiconductor layer SAR while being disposed across it. The red switching source electrode SSR branches from the red data line DLR and contacts one side of the red switching semiconductor layer SAR. The red switching drain electrode SDR is in contact with the other side of the red switching semiconductor layer SAR.

The red driving gate electrode DGR extends from or is connected to the red switching drain electrode SDR. The red driving semiconductor layer DAR is disposed across the red driving gate electrode DGR. The red driving source electrode DSR is a part of the driving wiring horizontal portion VDH and is in contact with one side of the red driving semiconductor layer DAR. The red driving drain electrode DDR is in contact with the other side of the red driving semiconductor layer DAR.

A red light emitting diode OLR is connected to the red driving drain electrode DDR. The red light emitting diode OLR is disposed in the first blue sub-pixel SPB1. In particular, it has a structure overlapping the first blue light emitting diode OLB1.

A first blue switching thin film transistor STB1 , a first blue driving thin film transistor SDB1 , a first blue light emitting diode OLB1 , and a red light emitting diode OLR are disposed in the first blue sub-pixel SPB1 . The first blue switching thin film transistor STB1 includes a first blue switching gate electrode SGB1 , a first blue switching semiconductor layer SAB1 , a first blue switching source electrode SSB1 , and a first blue switching drain electrode SDB1 . includes The first blue driving thin film transistor DTB1 includes a first blue driving gate electrode DGB1 , a first blue driving semiconductor layer DAB1 , a first blue driving source electrode DSB1 , and a first blue driving drain electrode DDB1 . includes

The first blue switching gate electrode SGB1 may have a structure branched from the scan line SL or may be defined as a part of the scan line SL. For example, the first blue switching gate electrode SGB1 may be defined in an overlapping portion while the first blue switching semiconductor layer SAB1 is disposed across. The first blue switching source electrode SSB1 branches from the first blue data line DLB1 and contacts one side of the first blue switching semiconductor layer SAB1 . The first blue switching drain electrode SDB1 is in contact with the other side of the first blue switching semiconductor layer SAB1.

The first blue driving gate electrode DGB1 extends from the first blue switching drain electrode SDB1. The first blue driving semiconductor layer DAB1 is disposed across the first blue driving gate electrode DGB1. The first blue driving source electrode DSB1 is a part of the driving wiring horizontal portion VDH and contacts one side of the first blue driving semiconductor layer DAB1 . The first blue driving drain electrode DDB1 is in contact with the other side of the first blue driving semiconductor layer DAB1.

A first blue light emitting diode OLB1 is connected to the first blue driving drain electrode DDB1 . The first blue light emitting diode OLB1 may have a stacked structure on the red light emitting diode OLR.

Hereinafter, a cross-sectional structure of a pair of sub-pixels adjacent to each other and overlapping with each other in the electroluminescent display according to the first embodiment will be described in detail with reference to FIG. 4 . 4 is a cross-sectional view showing the structure of the electroluminescent display device according to the first embodiment of this application, taken along the cut line I-I' of FIG. 3 . In the cross-sectional view, the driving thin film transistors DTR and DTB1 and the light emitting diodes OLR and OLB1 are mainly illustrated for convenience.

A red driving gate electrode DGR and a first blue driving gate electrode DGB1 are formed on the substrate SUB. A gate insulating layer GI is stacked on the driving gate electrodes DGR and DGB1. A red driving semiconductor layer DAR and a first blue driving semiconductor layer DAB1 are formed on the gate insulating layer GI. The central region of the red driving semiconductor layer DAR overlaps the red driving gate electrode DGR, and the central region of the first blue driving semiconductor layer DAB1 overlaps the first blue driving gate electrode DGB1. . An intermediate insulating layer ILD is stacked on the driving semiconductor layers DAR and DAB1.

Driving source electrodes DSR and DSB1 , driving drain electrodes DDR and DDB1 , and a red data line DLR are formed on the intermediate insulating layer ILD. Although not shown in FIG. 4 , the first blue data line DLB1 and the driving current line VDD may be further formed on the intermediate insulating layer ILD. The red driving source electrode DSR is in contact with one side of the red driving semiconductor layer DAR with respect to the red driving gate electrode DGR, and the red driving drain electrode DDR is the other side of the red driving semiconductor layer DAR. is in contact with The first blue driving source electrode DSB1 is in contact with one side of the first blue driving semiconductor layer DAB1 with respect to the first blue driving gate electrode DGB1 , and the first blue driving drain electrode DDB1 is the first It is in contact with the other side of the blue driving semiconductor layer DAB1.

A passivation layer PAS is stacked on the driving thin film transistors DTR and DTB1. A planarization layer PLN is stacked on the passivation layer PAS. The planarization layer PLN is used to uniform the upper surface of the substrate SUB on which the thin film transistors are partially formed, and may be formed of an organic material.

In the planarization layer PLN, the red sub-pixel SPR disposed adjacent to each other and the light guide LG disposed under the first blue sub-pixels SPB1 are disposed. The light guide LG may have a cross-sectional structure of an inverted triangle, a wedge, or a 'V' shape. The light guide LG may include a first inclined surface 100 , a second inclined surface 200 , an upper surface 300 , and a top 400 .

The upper surface 300 may have an area corresponding to the entire area of the red sub-pixel SPR and the first blue sub-pixel SPB1 . The upper surface 300 is a part of the upper surface of the planarization layer PLN. The apex 400 is preferably disposed to correspond to a boundary between the red sub-pixel SPR and the first blue sub-pixel SPB1 . The first inclined surface 100 is a wall surface connecting one side of the upper surface 300 and the apex 400 , and the second inclined surface 200 is the second inclined surface 200 connecting the other side of the upper surface 300 and the apex 400 . It could be a wall.

Preferably, the first inclined surface 100 is disposed to correspond to the surface area of the red sub-pixel SPR in the lower region of the red sub-pixel SPR. Similarly, it is preferable that the second inclined surface 200 corresponds to the surface area of the first blue sub-pixel SPB1 in the lower region of the first blue sub-pixel SPB1 . The angle between the first inclined surface 100 and the second inclined surface 200 , that is, the angle of the apex 400 may have any one angle set between 120 degrees and 60 degrees. Preferably, the angle of the apex 400 may be set to 90 degrees.

A first reflective layer TRE is formed on the entire surface of the first inclined surface 100 . A light absorption layer LA and a second reflection layer PRE are formed on the second inclined surface 200 . The light absorption layer LA may occupy at least 90% or more of the total area of the second inclined surface 200 , and the second reflective layer PRE may occupy 10% or less of the total area of the second inclined surface 200 .

The upper surface 300 is disposed across the red sub-pixel SPR and the first blue sub-pixel SPB1 . A red color filter CFR and a lens layer LEN are formed on the upper surface 300 that is a part of the planarization layer PLN. The red color filter CFR is disposed to correspond to the area of the red sub-pixel SPR. The lens layer LEN is disposed to correspond to the area of the first blue sub-pixel SPB1 . In particular, the lens layer LEN has a focal length in which the focus is set on the second reflective layer PRE of the second inclined surface 200 . For example, the second reflective layer PRE may be disposed in a central portion of the second inclined surface 200 .

The wedge-shaped light guide LG may be formed by patterning the planarization layer PLN. For example, the planarization layer PLN is patterned to form a space including the first inclined surface 100 , the second inclined surface 200 , and the apex 400 having a 'V' shape. Thereafter, a first reflective layer TRE is formed on the first inclined surface 100 and a second reflective layer PRE is formed on the second inclined surface 200 . In addition, the light absorption layer LA is formed on the second inclined surface 200 in an area excluding a portion corresponding to the focal length of the lens layer LEN.

Thereafter, the light guide LG is completed by filling the wedge-shaped empty space with a transparent organic material. Here, the organic material may be the same material as the planarization layer PLN. If necessary, a transparent organic material having a refractive index lower than that of the planarization layer PLN may be included. Also, in some cases, the planarization layer PLN may be formed of an opaque organic material, unlike a material filling the inside of the light guide LG.

The lens layer LEN is formed only in the area corresponding to the first blue sub-pixel SPB1 on the upper surface 300 . The lens layer LEN may be formed of a transparent organic material filling the inside of the light guide LG. Alternatively, in order to increase the concentration of light passing through the lens layer LEN, the transparent organic material may be formed of a material having a refractive index greater than that of the organic material filling the inside of the light guide LG.

A first transparent electrode AN1 is formed on the lens layer LEN. The first transparent electrode AN1 may have a larger size to completely cover the lens layer LEN. The first transparent electrode AN1 is connected to the driving drain electrode DDR of the red driving light emitting diode DTR through a contact hole formed in the planarization layer PLN and the passivation layer PAS. A first bank BN1 covering an edge of the first transparent electrode AN1 is formed. The first bank BN1 may cover the contact formed in the planarization layer PLN and the passivation layer PAS. The first transparent electrode AN1 exposed by the first bank BN1 may be an anode electrode of the red light emitting diode OLR.

A first light emitting layer EL1 is stacked on the first transparent electrode AN1 . The first light emitting layer EL1 is disposed in the light emitting area defined by the first bank BN1 . The first light emitting layer EL1 may include a light emitting material emitting yellow light. or a light emitting material emitting white light. As another example, it may include a red light-emitting material that emits red light.

A reflective electrode AN2 may be stacked on the first emission layer EL1 . The reflective electrode AN2 may be connected to the first blue driving drain electrode DDB1 of the first blue driving thin film transistor DTB1 through a contact hole formed in the first bank BN1 . The reflective electrode AN2 may be a cathode electrode of the red light emitting diode OLR and an anode electrode of the first blue light emitting diode OLB1. In FIG. 4 , an intermediate electrode IE connected to the first blue driving drain electrode DDB1 through a contact hole formed in the planarization layer PLN is further provided, and the reflective electrode AN2 is a first electrode covering the intermediate electrode IE. A structure connected through a contact hole formed in the bank BN1 is illustrated. 4 illustrates an example of a connection structure between the driving thin film transistors DTR and DTB1 and the anode electrodes AN1 and AN2. However, it is not limited to this structure and may be implemented in various ways.

A second bank BN2 may be formed on the reflective electrode AN2 . The second bank BN2 may have a structure in which the central portion of the reflective electrode AN2 and the central portion of the red color filter CFR are exposed and the other areas are covered. A second light emitting layer EL2 is stacked on the reflective electrode AN2 exposed by the second bank BN2 . The second light emitting layer EL2 may include an organic light emitting material emitting blue light.

A second transparent electrode CAT is stacked on upper surfaces of the second bank BN2 , the red color filter CFR, and the second emission layer EL2 . The second transparent electrode CAT may be a transparent conductive material covering the entire substrate. The second transparent electrode CAT may be a cathode electrode of the first blue light emitting diode OLB1. Although not shown in the drawing, the second transparent electrode CAT may be connected to a terminal supplying a common voltage.

In addition, although not shown in the drawings, an encapsulation layer may be laminated on the second transparent electrode CAT or an encapsulation substrate may be bonded. Thereby, the electroluminescent display device is completed.

Hereinafter, a mechanism for implementing color in the electroluminescent display according to the first embodiment of the present application will be described with reference to FIGS. 5A and 5B . For convenience, a mechanism for implementing colors in a pair of red sub-pixels SPR and first blue sub-pixels SPB1 in the unit pixel UP will be described.

5A is a perspective view illustrating a structure of a light guide disposed in a pair of sub-pixels constituting the electroluminescent display device according to the first embodiment of the present application. 5B is a cross-sectional view showing the cross-sectional structure of the light guide according to the first embodiment of the present application.

Light emitted from the first light emitting layer EL1 of the red light emitting diode OLR disposed on the lens layer LEN passes through the first transparent electrode AN1 and passes through the lens layer LEN to the lens layer LEN. The light is focused on the second reflective layer PRE disposed at the focal position of .

The light focused on the second reflective layer PRE is reflected by the second reflective layer PRE and is reflected to the opposite first reflective layer TRE. In this case, the light reflected from the second reflective layer PRE may be reflected while being diffused according to the optical path. All of the light incident on the first reflective layer TRE is reflected to the upper surface 300 . In this case, since the red color filter CFR is disposed on the upper surface 300 corresponding to the first reflective layer TRE, red light is emitted from the red sub-pixel SPR.

Meanwhile, a first blue light emitting diode OLB1 is stacked on the red light emitting diode OLR. Light emitted from the second light emitting layer EL2 of the first blue light emitting diode OLB1 passes through the second transparent electrode CAT and exits to the upper portion of the first blue sub pixel SPB1 . In this case, since the second light emitting layer EL2 is made of only an organic light emitting material emitting blue light, blue light is emitted.

As described above, the pair of red sub-pixels SPR and the first blue sub-pixels SPB1 constituting the unit pixel UP are driven by respective driving thin film transistors DTR and DTB1 to emit red and blue light, respectively. do.

Hereinafter, a reflection path of external light in the pixel structure according to the first embodiment will be described with reference to FIG. 5C . 5C is a cross-sectional view illustrating a cross-sectional structure of a light guide and an optical path of external light according to the first embodiment of the present application.

External light incident on the red sub-pixel SPR travels along a light path indicated by a solid line. For example, all incident external light is reflected by the first reflective layer TRE disposed on the first inclined surface 100 , and the light absorption layer LA and the second reflective layer PRE disposed on the second inclined surface 100 . proceed with All of the external light incident to the light absorption layer LA is absorbed. On the other hand, external light incident on the second reflective layer PRE is reflected and travels to an upper portion of the first blue sub-pixel SPB1 . The reflected external light is re-reflected by the reflective electrode AN2 which is the cathode electrode of the red light emitting diode OL1 and the anode electrode of the first blue light emitting diode OL2. The re-reflected external light follows the light path shown by the dotted line. For example, external light re-reflected by the reflective electrode AN2 is reflected by the second reflective layer PRE, is reflected by the first reflective layer TRE, and returns to the red sub-pixel SPR.

Most of the external light incident to the red sub-pixel SPR is absorbed by the absorption layer LA, and only a very small amount of light is reflected back to the red sub-pixel SPR and emitted. When the area ratio of the absorption layer LA on the second inclined surface 200 is 90% or more and the area ratio of the second reflective layer PRE on the second inclined surface 200 is 10% or less, the red sub-pixel The amount of light that is reflected by the external light incident to (SPR) and emitted again can be suppressed to an amount less than 10%. In particular, since about 10% of the amount of light passing through the inside of the light guide LG is partially lost in the repeated reflection process, the amount of reflected light from the external light that is finally reflected and emitted to the red sub-pixel SPR is 10 It can be less than %.

On the other hand, external light incident on the first blue sub-pixel SPB1 is reflected by the reflective electrode AN2 of the first blue light emitting diode OL2 . When the reflectivity of the reflective electrode AN2 is 95% or more, the amount of light corresponding to 95% of the external light is reflected as it is.

However, the amount of light reflected to the outside among the external light incident on all of the pair of sub-pixels SPR and SPB1 may be controlled to be less than 50%. This is equivalent to the reflection reducing ability when an optical element is used to reduce external light reflection in the structure of the conventionally known organic light emitting diode display device. On the other hand, when an optical element is used, there is a problem that the amount of light for image display emitted from the light emitting element is also reduced by about 50%, but in the structure according to this application, the amount of light for image display can be provided without any loss .

The electroluminescent display device according to the first embodiment of the present application is characterized in that the amount of light for displaying an image emitted from itself does not decrease while reducing the reflectance of external light. Since external light reflection is minimized and there is no loss of self-emission light, a brighter image can be provided with the same power consumption. Accordingly, it is possible to provide high-quality images while reducing power consumption.

Hereinafter, a driving signal application method for driving a pair of sub-pixels in the electroluminescent display device according to the first embodiment will be described with reference to FIG. 6 . 6 is a diagram illustrating a method of driving a sub-pixel of the electroluminescence display according to the first embodiment.

6 illustrates only a simple structure in which a red light emitting diode OLR and a first blue light emitting diode OLB1 are stacked. A first transparent electrode AN1, a first light emitting layer EL1 thereon, and a reflective electrode AN2 are stacked thereon to form a red light emitting diode OLR. In addition, the reflective electrode AN2, the second light emitting layer EL2 thereon, and the second transparent electrode CAT are stacked thereon to configure the first blue light emitting diode OLB1.

Due to a voltage difference between the first transparent electrode AN1 and the reflective electrode AN2 , the first emission layer EL1 may emit light. Also, the second light emitting layer EL2 may emit light due to a voltage difference between the reflective electrode AN2 and the second transparent electrode CAT.

According to an example, a yellow light emitting signal (Yellow data) is applied to the first transparent electrode AN1, a blue light emitting signal is applied to the reflective electrode AN2, and a ground signal (Ground: GND) is applied to the second transparent electrode CAT. ) can be approved. A thick dotted line indicates a voltage (corresponding to a yellow emission signal) applied to the first transparent electrode AN1 , and a thick solid line indicates a voltage (corresponding to a blue emission signal) applied to the second transparent electrode AN2 .

In this connection structure, by applying the voltage shown below in FIG. 6 , the first light emitting layer EL1 emitting yellow light and the second light emitting layer EL2 emitting blue light may be simultaneously driven.

For example, the GND signal is always applied to the second transparent electrode CAT. In this state, when 6V is applied to the first transparent electrode AN1 and 4V is applied to the reflective electrode AN2, yellow light corresponding to 2V is emitted from the first light-emitting layer EL1 and 4V from the second light-emitting layer EL2. The blue light corresponding to

In addition, when 6V is applied to the first transparent electrode AN1 and 2V is applied to the reflective electrode AN2, yellow light corresponding to 4V is emitted from the first light-emitting layer EL1, and at 2V from the second light-emitting layer EL2. A corresponding blue light is emitted.

On the other hand, when 2V is applied to the first transparent electrode AN1 and 0V is applied to the reflective electrode AN2 , yellow light corresponding to 2V is emitted from the first light-emitting layer EL1 and light is emitted from the second light-emitting layer EL2 . doesn't happen

In addition, when 0V is applied to the first transparent electrode AN1 and 2V is applied to the reflective electrode AN2 , no light is emitted from the first light-emitting layer EL1 and blue light corresponding to 2V is emitted from the second light-emitting layer EL2 . do.

What has been described herein corresponds to an example of the driving method related to the structure of the electroluminescent display according to the first embodiment, and is not limited thereto, and may be implemented in other ways.

<Second embodiment>

Referring to FIG. 7 , a second embodiment of this application will be described. Since there is no difference in the structure of the electroluminescent display device according to the second embodiment in a plan view, reference is made to FIG. 2 . 7 is a cross-sectional view showing the structure of the electroluminescent display device according to the second embodiment of the present application, taken along the cut line I-I' of FIG. 2 .

Referring to FIG. 7 , almost all structures are the same as those of the electroluminescent display device according to the first embodiment shown in FIG. 4 . The difference is that the reflective electrode AN2 is connected to the common voltage terminal GN, and the second transparent electrode CAT is connected to the first blue driving drain electrode DDB1 of the first blue driving thin film transistor DTB1. there is to be

The red light emitting diode OLR and the first blue light emitting diode OLB1 have substantially the same shape and size and are stacked. The red light emitting diode OLR includes a first transparent electrode AN1 , a first emission layer EL1 , and a reflective electrode AN2 . Here, the first transparent electrode AN1 may be used as an anode electrode, and the reflective electrode AN2 may be used as a cathode electrode.

The first blue light emitting diode OLB1 includes a reflective electrode AN2 , a second light emitting layer EL2 , and a second transparent electrode CAT. Here, the reflective electrode AN2 may be used as a cathode electrode, and the second transparent electrode AN2 may be used as an anode electrode.

In the second embodiment, the reflective electrode AN2 has a structure in which the red light emitting diode OLR and the first blue light emitting diode OLB1 are used as a common cathode electrode. Accordingly, the reflective electrode AN2 may be connected to the common power terminal GN through a contact hole penetrating the planarization layer PLN. Here, the common power terminal GN may be formed of the same material on the same layer as the red data line DLR. However, it is not limited to this structure and may be formed in other ways.

Hereinafter, a driving signal application method for driving a pair of sub-pixels in the electroluminescent display device according to the second embodiment will be described with reference to FIG. 8 . 8 is a diagram illustrating a method of driving a sub-pixel of an electroluminescence display according to a second embodiment.

8 illustrates only a simple structure in which a red light emitting diode OLR and a first blue light emitting diode OLB1 are stacked. A first transparent electrode AN1, a first light emitting layer EL1 thereon, and a reflective electrode AN2 are stacked thereon to form a red light emitting diode OLR. In addition, the reflective electrode AN2, the second light emitting layer EL2 thereon, and the second transparent electrode CAT are stacked thereon to configure the first blue light emitting diode OLB1.

Due to a voltage difference between the first transparent electrode AN1 and the reflective electrode AN2 , the first emission layer EL1 may emit light. Also, the second light emitting layer EL2 may emit light due to a voltage difference between the reflective electrode AN2 and the second transparent electrode CAT.

In one example, a yellow light emitting signal (Yellow data) is applied to the first transparent electrode AN1, a ground signal (GND) is applied to the reflective electrode AN2, and a blue light emitting signal (Blue data) is applied to the second transparent electrode CAT. ) can be approved.

In this connection structure, by applying the voltage shown below in FIG. 8 , the first light emitting layer EL1 emitting yellow light and the second light emitting layer EL2 emitting blue light are simultaneously driven.

For example, the GND signal is always applied to the reflective electrode AN2 . In this state, when 2V is applied to the first transparent electrode AN1 and 4V is applied to the second transparent electrode CAT, yellow light corresponding to 2V is emitted from the first light-emitting layer EL1 and the second light-emitting layer EL2 blue light corresponding to 4V is emitted.

In addition, when 4V is applied to the first transparent electrode AN1 and 2V is applied to the second transparent electrode CAT, yellow light corresponding to 4V is emitted from the first light-emitting layer EL1, and from the second light-emitting layer EL2 Blue light corresponding to 2V is emitted.

On the other hand, when 2V is applied to the first transparent electrode AN1 and 0V is applied to the second transparent electrode CAT, yellow light corresponding to 2V is emitted from the first light emitting layer EL1 and from the second light emitting layer EL2 No light is generated.

And, when 0V is applied to the first transparent electrode AN1 and 2V is applied to the second transparent electrode CAT, no light is generated in the first light-emitting layer EL1 and blue light corresponding to 2V in the second light-emitting layer EL2 is applied. it glows

What has been described herein corresponds to an example of the driving method related to the structure of the electroluminescent display according to the second embodiment, and is not limited thereto, and may be implemented in other ways.

Hereinafter, an arrangement structure of various sub-pixels constituting a unit pixel of an electroluminescence display according to this application will be described with reference to FIGS. 9 and 10 . The structure described below can be applied to the first and second embodiments described above. 9 is a plan view illustrating an area ratio of sub-pixels constituting a unit pixel in an electroluminescence display according to an embodiment of the present application.

Referring first to FIG. 9 , the electroluminescent display according to this application includes a plurality of unit pixels UP. One unit pixel UP includes four sub-pixels. For example, one unit pixel UP includes a red sub-pixel SPR, a first blue sub-pixel SPB1 , a green sub-pixel SPG, and a second blue sub-pixel SPB2 . The red sub-pixel SPR and the first blue sub-pixel SPB1 form a pair, and the green sub-pixel SPG and the second blue sub-pixel SPB2 form another pair.

In this case, the area ratio of the red sub-pixel SPR, the first blue sub-pixel SPB1, the green sub-pixel SPG, and the second blue sub-pixel SPB2 may be set to 1:1:1:1. . In this case, external light reflection is less than 95% in the first blue sub-pixel SPB1 and the second blue sub-pixel SPB2, and less than 10% in the red sub-pixel SPR and the green sub-pixel SPG. Therefore, the overall reflectance of the reflected light does not exceed 50% at most.

Next, another example will be described with reference to FIG. 10 . 10 is a plan view illustrating an area ratio of sub-pixels constituting a unit pixel in an electroluminescent display device according to another embodiment of the present application.

One unit pixel UP includes four sub-pixels. For example, one unit pixel UP includes a red sub-pixel SPR, a first blue sub-pixel SPB1 , a green sub-pixel SPG, and a second blue sub-pixel SPB2 . The red sub-pixel SPR and the first blue sub-pixel SPB1 form a pair, and the green sub-pixel SPG and the second blue sub-pixel SPB2 form another pair.

In this case, the area ratio of the red sub-pixel SPR, the first blue sub-pixel SPB1 , the green sub-pixel SPG, and the second blue sub-pixel SPB2 may be set to 2:1:2:1. . In this case, external light reflection is less than 95% in the first blue sub-pixel SPB1 and the second blue sub-pixel SPB2, and less than 10% in the red sub-pixel SPR and the green sub-pixel SPG. Therefore, the overall reflectance of the reflected light does not exceed the maximum of 35%.

In addition, the reflectance of external light may be further reduced by adjusting the optical characteristics of the reflective electrode AN2 , while the amount of self-emission may be secured to the maximum. For example, the reflective electrode AN2 may be formed of a material and structure having high reflectivity with respect to light having a specific wavelength. That is, it may have a metal material or a laminated structure having high reflectance with respect to light of blue and yellow wavelengths but low reflectance with respect to light of other wavelengths. In this case, it is possible to further reduce the reflectance of external light by lowering the reflectance of light of a wavelength band other than blue light and yellow light. On the other hand, since the reflectance of blue is high, luminous efficiency in the first blue sub-pixel SPB1 and the second blue sub-pixel SPB2 can be secured to the maximum.

Meanwhile, in the red sub-pixel SPR and the green sub-pixel SPG, the color of yellow light emitted from the first light-emitting layer EL1 including a yellow light-emitting material and reflected by the reflective electrode AN2 is changed to a color filter. to implement Accordingly, since the reflective electrode AN2 has a structure in which the reflectance of the yellow light is maximized, the amount of light emitted from the red sub-pixel SPR and the green sub-pixel SPG can be maximized.

Features, structures, effects, etc. described in the above-described examples of this application are included in at least one example of this application, and are not necessarily limited to only one example. Furthermore, features, structures, effects, etc. illustrated in at least one example of this application may be combined or modified with respect to other examples by those of ordinary skill in the art to which this application belongs. Accordingly, the contents related to such combinations and variations should be interpreted as being included in the scope of this application.

This application described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the technical field to which this application pertains that various substitutions, modifications and changes are possible within the scope not departing from the technical matters of this application. It will be clear to those who have the knowledge of Therefore, the scope of this application is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of this application.

UP: unit pixel SPR: red sub pixel
SPB1: first blue sub-pixel SPB2: second blue sub-pixel
SPG: green sub-pixel LEN: lens layer
CFR: Red color filter CFG: Green color filter
AN1: first transparent electrode EL1: first light emitting layer
AN2: reflective electrode EL2: second light emitting layer
CAT: second transparent electrode LG: light guide
100: first inclined surface 200: second inclined surface
300: upper surface 400: top
TRE: first reflective layer PRE: second reflective layer
LA: light absorption layer
OLR: red light emitting diode OLB1: first blue light emitting diode
OLG: green light emitting diode OLB2: second blue light emitting diode

Claims (15)

a first sub-pixel on which a first color filter is disposed;
a second sub-pixel disposed adjacent to the first sub-pixel and including a sequentially stacked lens layer, a first transparent electrode, a first emission layer, a reflective electrode, a second emission layer, and a second transparent electrode;
a light guide disposed in a space below the first sub-pixel and the second sub-pixel;
The light guide has a wedge shape having a vertex in contact with each other at a boundary between the first sub-pixel and the second sub-pixel, and an upper surface corresponding to an area of the first sub-pixel and the second sub-pixel. electroluminescent display. The method of claim 1,
The first light-emitting layer comprises a yellow light-emitting material,
The second light emitting layer includes a blue light emitting material. The method of claim 1,
Driving the first light emitting layer by the voltage difference between the first transparent electrode and the regular reflective electrode,
The light emitted from the first emission layer is emitted in an upper direction of the first sub-pixel through the light guide unit. The method of claim 1,
Driving the second light emitting layer by the voltage difference between the reflective electrode and the second transparent electrode,
The light emitted from the second emission layer is emitted in an upper direction of the second sub-pixel. The method of claim 1,
A first driving thin film transistor connected to the first transparent electrode is disposed in the first sub-pixel;
A second driving thin film transistor connected to the reflective electrode is disposed in the second sub-pixel;
and the second transparent electrode is connected to a common power terminal. The method of claim 1,
A first driving thin film transistor connected to the first transparent electrode is disposed in the first sub-pixel;
A second driving thin film transistor connected to the second transparent electrode is disposed in the second sub-pixel;
The reflective electrode is connected to a common power supply terminal. The method of claim 1,
The light guide is
a first inclined surface disposed under the first sub-pixel;
a second inclined surface disposed under the second sub-pixel;
a first reflective layer disposed on the entire surface of the first inclined surface;
a second reflective layer disposed at a focal position of the lens layer on the second inclined surface; And
and a light absorbing layer disposed on a portion of the second inclined surface excluding the second reflective layer. 8. The method of claim 7,
The light emitted from the first light emitting layer,
After being condensed to the second reflective layer by the lens layer, it is reflected by the first reflective layer,
Light is emitted from the first reflective layer in an upper direction of the first sub-pixel through the first color filter,
The light emitted from the second light emitting layer,
An electroluminescent display device that is reflected from the reflective electrode and emitted in an upper direction of the second sub-pixel through the second transparent electrode. 8. The method of claim 7,
External light incident through the first color filter,
is reflected from the first reflective layer and transmitted to the second inclined surface,
Most of the light reaching the light absorbing layer is extinguished, and only the light incident on the second reflective layer is incident on the reflective electrode through the lens layer. 10. The method of claim 9,
The external lights incident on the reflective electrode are
A certain amount of light is absorbed by the reflective electrode,
An electroluminescent display device in which only the remaining small amount of light is sequentially reflected by the second reflective layer and the first reflective layer to be reflected upwardly of the first sub-pixel. 10. The method of claim 9,
An electroluminescent display device, wherein a ratio of light reflected upwardly of the first sub-pixel among the incident external light is 10% or less. The method of claim 1,
An area ratio of the first sub-pixel to the area of the second sub-pixel is any one selected from 1:1 to 2:1. The method of claim 1,
a third sub-pixel adjacent to the second sub-pixel and facing the first sub-pixel; And
a fourth sub-pixel adjacent to the third sub-pixel and facing the second sub-pixel;
The third sub-pixel includes a second color filter,
The fourth sub-pixel has the same structure as the third sub-pixel. 14. The method of claim 13,
the first sub-pixel to the fourth sub-pixel form one unit pixel;
The first color filter includes a red color filter,
The second color filter includes a green color filter,
The second light emitting layer disposed on each of the second sub-pixel and the fourth sub-pixel includes a blue light emitting material. 14. The method of claim 13,
The ratio of the area of the first sub-pixel, the area of the second sub-pixel, the area of the third sub-pixel, and the area of the fourth sub-pixel is selected from 1:1:1:1 to 2:1:2:1. Any one of the electroluminescent display device.

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