KR100683670B1 - Organic electro-luminescent display device comprising optical micro-cavity - Google Patents

Abstract

The present invention provides an organic electroluminescent display device that can reduce power consumption while improving light extraction efficiency, brightness, and color purity according to the optical resonance effect. An organic electroluminescent display comprising a graphic unit for outputting, comprising: a transparent substrate; A first electrode layer and a second electrode layer formed on the transparent substrate; An organic film interposed between the first electrode layer and the second electrode layer and having a light emitting layer that emits light by electric driving of the first electrode layer and the second electrode layer; And an optical resonant layer interposed between the transparent substrate and the first electrode layer, wherein the optical resonant layer is disposed only in the graphic unit without the icon unit.

Description

Organic electro-luminescent display device comprising optical micro-cavity layer

1 is a cross-sectional view of a PM type organic light emitting display device according to an exemplary embodiment of the present invention.

2 is a plan view of an organic light emitting display device according to a preferred embodiment of the present invention.

3 is a cross-sectional view of an AM type organic electroluminescent device according to another preferred embodiment of the present invention.

4 is a cross-sectional view of an AM type organic electroluminescent device according to another exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10,30: transparent substrate 11,39: first electrode layer

12: internal insulating film 13,132,133,134: organic film

14, 42: second electrode layer 15: sealing portion

20: optical resonant layer 20a, 20b, 20R, 20G, 20B: dielectric layer

32: semiconductor active layer 34: gate electrode

36: drain electrode 37: source electrode

100a: graphic part 100b: icon part

The present invention relates to an organic light emitting display device, and more particularly, to an electroluminescent display device in which light extraction efficiency is improved due to a light resonance effect and power consumption is reduced.

In general, an electroluminescent display is a self-luminous display that electrically excites a fluorescent compound to emit light, which can be driven at a low voltage, is easy to thin, and has been pointed out as a problem in a liquid crystal display such as a wide viewing angle and a fast response speed. It is attracting attention as the next generation display that can solve the problem.

The electroluminescent device may be classified into an inorganic electroluminescent device and an organic electroluminescent device according to whether the material forming the light emitting layer is an inorganic material or an organic material.

Meanwhile, in the organic light emitting display device, an organic layer having a predetermined pattern is formed on a transparent insulating substrate such as glass or plastic, and electrode layers are formed on upper and lower portions of the organic layer. The organic film consists of organic compounds. Materials for forming such organic films include phthalocyanine (CuPc: copper phthalocyanine), N, N-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (N, N'-Di (naphthalene-1) -yl) -N, N'-diphenyl-benzidine (NPB), tris-8-hydroxyquinoline aluminum (Alq3), etc. are used.

In the organic light emitting display device configured as described above, as the anode and cathode voltages are applied to the electrodes, holes injected from the electrode to which the anode voltage is applied are moved to the light emitting layer via the hole transport layer, and the electrons have a cathode voltage. It is injected from the applied electrode into the light emitting layer via the electron transport layer. In this light emitting layer, electrons and holes recombine to produce excitons, and as the excitons change from the excited state to the ground state, the fluorescent molecules in the light emitting layer emit light to form an image. The excitons, when classified into energy states, have one singlet state and three triplet states. Due to the bandgap energy characteristic, the singlet energy state emits light, but the triplet state energy is changed to thermal energy without emitting light.

As described above, the light efficiency of the organic light emitting display device driven is divided into internal efficiency and external efficiency. Among these, the internal efficiency depends on the photoelectric conversion efficiency of the organic light emitting material. The external efficiency is also called light coupling efficiency and depends on the refractive index of each layer constituting the organic light emitting display device. In the case of the light extraction efficiency, which is an external efficiency, the light extraction efficiency of the organic light emitting display device is lower than that of other display devices such as cathode ray tubes and PDPs. There is plenty of room for improvement.

As described above, the biggest reason why the light extraction efficiency of the conventional organic light emitting display device is lower than that of other display devices is that when the light emitted by the organic layer is emitted above the critical angle, the layer and the substrate having the high refractive index, such as the ITO electrode layer, This is because total reflection occurs at the interface between the layers having the low refractive index, and the extraction to the outside is prevented. Therefore, due to the total reflection problem at the interface, only about 1/4 of the light emitted from the organic light emitting layer in the organic light emitting display device may be extracted to the outside.

Such light extraction efficiency varies depending on the thickness of the ITO electrode and the refractive index of the substrate, but the actual ITO electrode has a thickness of about 150 to 200 nm in consideration of the electrical characteristics and the process characteristics of the ITO. Only about 23% light extraction efficiency can be obtained.

An example of a conventional organic electroluminescent display for preventing such a decrease in light extraction rate is disclosed in Japanese Laid-Open Patent Publication No. 63-172691. The disclosed organic electroluminescent display includes a substrate having light condensation such as a protruding lens. However, such a convex lens for condensing is difficult to form on the substrate because the pixel according to the emission of the organic film is very small.

Japanese Laid-Open Patent Publication No. 62-172691 discloses an organic material having a first dielectric layer interposed between a transparent electrode layer and a light emitting layer and a second dielectric layer having a refractive index in the middle of the first dielectric layer and the transparent electrode on the transparent electrode side. An electroluminescent display is disclosed, and Japanese Patent Application Laid-Open No. Hei 1-220394 forms a lower electrode, an insulating layer, a light emitting layer, and an upper electrode on a substrate, and an organic electric field having a mirror formed on one surface of the light emitting layer to reflect light. A light emitting display device is disclosed.

However, such an organic light emitting display device has a very thin thickness of the light emitting layer, so it is very difficult to install a mirror for reflection on the side surface, and as a result, a production cost rises.

In order to solve these problems, Japanese Laid-Open Patent Publication No. 11-283751 discloses an organic electroluminescent display device having one or more organic layers between an anode and a cathode, and includes a structure including a diffraction grating or a zone plate as a component. Is disclosed. This is to form the diffraction grating near the boundary where the refractive index is different and to extract the light of the organic film by the light scattering effect. However, such a diffraction grating layer is complicated in actual manufacturing process, it is difficult to form a pattern of the upper layer of the thin film due to the surface curvature, there is a problem that a separate planarization process must be added to fill the surface curvature.

In addition, in order to improve the problems of the organic electroluminescent display device, Japanese Unexamined Patent Application Publication Nos. 8-250786, 8-213174, and 10-177896 disclose an optical microcavity concept. An organic electroluminescent display is disclosed. In the disclosed organic electroluminescent display, a multi-layered dichroic mirror is formed between the glass substrate and the ITO electrode, and the semi-transmissive mirror functions as an optical resonator with a metal cathode serving as a reflecting plate. do. At this time, the transflective mirror is formed by alternately stacking a TiO ₂ layer having a high refractive index and a SiO ₂ layer having a low refractive index to form a multilayer, and adjusting the reflectance as the thickness and the number of the layers of the multilayer to light resonance Design the function. However, the optical resonator needs to increase the number of layers because the reflection property is improved as the number of layers forming the transflective mirror increases, but the complexity of the process of the organic light emitting display device increases as the number of layers increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an organic light emitting display device which can improve light extraction efficiency by having a simple laminated structure causing a resonance effect.

Another object of the present invention is to provide an organic light emitting display device which can reduce power consumption while improving luminance and color purity according to an optical resonance effect.

It is still another object of the present invention to provide an organic light emitting display device which can reduce the manufacturing cost while improving luminance and color purity according to the optical resonance effect.

The present invention devised to achieve the above object,

An organic electroluminescent display comprising an icon portion for outputting fixed light emission and a graphics portion for outputting variable light emission.

Transparent substrates;

A first electrode layer and a second electrode layer formed on the transparent substrate;

An organic film interposed between the first electrode layer and the second electrode layer and having a light emitting layer that emits light by electric driving of the first electrode layer and the second electrode layer; And

And an optical resonance layer interposed between the transparent substrate and the first electrode layer.

The optical resonant layer is disposed only on the graphic unit except for the icon unit.

According to another feature of the invention, the second electrode layer is made of a metal electrode, the optical distance between the second electrode layer and the optical resonance layer is preferably N / 2 times the optical distance of the emission wavelength (N is an integer). Do.

According to another feature of the invention, the optical resonance layer is preferably made of at least one or more pairs of dielectrics having different refractive indices.

According to another feature of the invention, the optical resonant layer may include a first dielectric layer made of TiO ₂ and a second dielectric layer made of SiO ₂ .

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

FIG. 1 is a schematic cross-sectional view of an organic light emitting display device according to a first exemplary embodiment of the present invention, and FIG. 1 illustrates an organic light emitting display device of a passive matrix type (PM).

1 is a cross-sectional view of the graphic unit 100a for outputting variable light emission, and a cross-sectional view of the icon unit 100b for outputting fixed light emission is shown on the left side of FIG. In the organic light emitting display according to the present invention, as shown in the plan view of FIG. 2, in the graphic unit 100a, each pixel (or R, G, B) according to an image signal transmitted by a scan line and a data line is used. Sub-pixel) outputs light emission, while icon unit 100b outputs fixed light emission by a fixed electrode or a fixed light emitting layer. Therefore, inevitably, the graphics unit 100a consumes more power than the icon unit 100b. The graphic unit 100a may be formed of an area color display device in which colors are divided according to predetermined areas of a pixel to be displayed.

In the graphic unit 100a of the organic light emitting display according to the present invention, as shown in the cross-sectional view on the right side, the first electrode layer 11 is formed in a predetermined pattern on the upper surface of the transparent substrate 10 made of a transparent material. And an organic layer 13 including at least an organic light emitting layer on the first electrode layer 11, and crossing the first electrode layer 11 on the organic layer 13. The second electrode layer 14 is formed. In addition, an upper portion of the second electrode layer 14 may further include a sealing part 15 to seal the first electrode layer 11, the organic layer 13, and the second electrode layer 14 from the outside. According to a first preferred embodiment of the present invention, the optical resonant layer 20 formed of a single film is provided between the transparent substrate 10 and the first electrode layer 11.

In the drawings, for convenience of description, the terminal unit and the circuit configuration to which power is applied to each electrode layer are not shown, and the description thereof will be omitted.

The transparent substrate 10 may be a transparent glass material, a plastic material or a silicon oxide substrate, and a soda lime substrate may be used according to a preferred embodiment of the present invention. Although not shown in the drawings, the upper surface of the transparent substrate 10 may further include a buffer layer to block the smoothness of the substrate and the penetration of the impurity element, the buffer layer may be formed of SiO ₂ or the like.

The first electrode layer 11 stacked on the transparent substrate 10 may be formed of a conductive material of a transparent material, and may be formed of indium tin oxide (ITO), and a predetermined pattern may be formed by a photolithography method. It may be formed to. The pattern of the first electrode layer 11 may be formed of lines on a stripe spaced apart from each other by a predetermined distance. The first electrode layer 11 provided with ITO may be connected to an external first electrode terminal (not shown) to serve as an anode electrode.

The internal insulating layer 12 may be formed on the transparent substrate 10 on which the first electrode layer 11 is formed to fill the space between the first electrode layer 11. The internal insulating layer 12 may be formed in a predetermined pattern by photolithography using photosensitive polyimide or photoresist, and expose the first electrode layer 11 to at least a portion corresponding to a pixel. The internal insulation layer 12 is intended for the purpose of clearly dividing the first electrode layer 11, and also has a function of preventing an electrical short between the second electrode layer 14 and the first electrode layer 11 to be laminated later. .

An organic layer 13 is formed on the inner insulating layer 12, and the organic layer 13 may be a low molecular organic material or a high molecular organic material.

In the case of a low molecular organic film formed of a low molecular organic material, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, an electron injection layer, or the like may be formed by stacking a single or a complex structure.

In addition, usable organic materials are copper phthalocyanine (CuPc), N, N-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (N, N'-Di (naphthalene-1-) yl) -N, N'-diphenyl-benzidine (NPB), tris-8-hydroxyquinoline aluminum (Alq3) and the like can be variously applied. The low molecular weight organic film may be formed by heating and depositing an organic material in a vacuum, and the formation of the organic light emitting layer is sequentially performed for each color through a mask provided with a slit of a predetermined pattern so as to correspond to each pixel. It can be formed by depositing.

Meanwhile, in the case of the polymer organic film formed of the polymer organic material, a hole transport layer (HTL) and an organic emission layer may be stacked. In addition, the polymer organic film may have various layered structures as in the case of the low molecular organic film. Of course. The polymer hole transport layer is made of polyethylene dihydroxythiophene (PEDOT: poly- (2,4) -ethylene-dihydroxy thiophene), polyaniline (PANI: polyaniline), or the like by inkjet printing or spin coating. It is formed on the first electrode layer 11 of the substrate 10, the polymer organic light emitting layer may be PPV, Soluble PPV's, Cyano-PPV, polyfluorene (Polyfluorene), etc., using inkjet printing or spin coating or laser The color pattern can be formed by a conventional method such as a thermal transfer method.

The second electrode layer 14 is formed in a pattern in which the second electrode layer 14 intersects the first electrode layer 11. The second electrode layer 14 is formed of aluminum / lithium fluoride (Al / LiF). It may be connected to an external first electrode terminal (not shown) to act as a cathode. The patterning of the second electrode layer 14 is difficult to be performed by the photolithography method like the first electrode layer 11 due to the organic film 13 which is vulnerable to moisture. Can be. In addition, although not illustrated, a cathode separator having a predetermined pattern may be formed at the time of forming the internal insulating layer 12 to enable pattern formation using the cathode separator. As shown in the arrow direction of FIG. 1, the second electrode layer 14 serves as a reflector of light emitted upward from the organic layer 13 when light is emitted from the organic layer 13 in the direction of the transparent substrate 10. Will also serve.

The upper part of the second electrode layer 14 is provided with a sealing portion 15, the sealing portion 15 may be provided with a metal cap having a moisture absorbent therein, or by applying a sealing resin material Allow moisture to be blocked inside. The seal 15 may also be formed using a substrate.

In the organic electroluminescent device as described above, the optical resonant layer 20 is further provided on the inner surface of the outermost member in the light emitting direction of the organic film 13. That is, as shown in FIG. 1, the optical resonant layer 20 is interposed between the transparent substrate 10 and the first electrode layer 11.

The optical resonant layer 20 is a dichroic mirror including at least one or more double layers including a low refractive index first dielectric layer 20a and a high refractive index second dielectric layer 20b. Optical micro-cavity is formed between the light emitting layer or the second electrode layer in order to cause optical resonance of light. In the optical resonant layer 20, it is preferable that the dielectric layer 20a having a small refractive index is formed on the light emitting direction side, and the dielectric layer 20b having a large refractive index is formed on the opposite side to the light emitting direction. In this case, light that leaks beyond the critical angle among the light traveling from the high refractive index second dielectric layer 20b to the low refractive index first dielectric layer 20a is totally reflected on the high refractive index second dielectric layer 20b and then Reflected by the second electrode layer 14 again, the phase with the light reflected at the interface between the first electrode layer 11 / optical resonant layer 20 and the transparent substrate 10 / optical resonant layer 20 in the same principle. When this coincides with each other, the light amplified by the transparent substrate 10 is caused by constructive interference with each other, thereby increasing the light extraction efficiency.

In order to cause constructive interference between unreflected light, reflected light, and re-reflected light, the optical distance between the second electrode layer 14 and the optical resonant layer 20 is determined by the light emitted from the light emitting layer. It is preferable that N / 2 times (N is an integer) of the optical distance of a wavelength.

According to a preferred embodiment of the present invention, the optical resonant layer 20 may be formed of a transparent or semitransparent first dielectric layer 20a mainly composed of SiO ₂ (refractive index n = about 1.5) and a first dielectric layer ( A transparent or translucent second dielectric layer 20b having TiO ₂ (refractive index n = about 2.2) having a higher refractive index than 20a) as a main component can be formed by a method such as vacuum deposition or sputtering. At this time, the refractive index depends on the thickness of the dielectric layer, so care should be taken.

The increase in light extraction efficiency may be achieved by appropriately adjusting the thickness of the optical resonant layer 20, the distance between the light emitting layer and the second electrode layer, and the number of dielectric layers.

Meanwhile, as shown in the cross-sectional view on the left side of FIG. 1, the icon unit 100b of the organic light emitting display device according to the present invention may have a first pattern in a predetermined pattern on the upper surface of the transparent substrate 10 made of a transparent material. An electrode layer 11 is formed, and an organic layer 13 including at least an organic light emitting layer is formed on the first electrode layer 11, and the first electrode layer 11 is formed on the organic layer 13. The second electrode layer 14 of a predetermined pattern is formed to intersect. In addition, an upper portion of the second electrode layer 14 may further include a sealing part 15 to seal the first electrode layer 11, the organic layer 13, and the second electrode layer 14 from the outside. However, the optical resonant layer 20 is not provided in the icon portion 100b.

As can be seen from the plan view of the organic electroluminescent display of FIG. 2, the optical resonant layer 20 is provided only to the graphic unit 100a having a high power consumption, and the icon unit 100b consumes power. Since it is small, it is for reducing manufacturing cost by not providing the optical resonant layer 20. FIG.

Particularly, in the case of the area color method in which colors are fixed for each area, since a single color of light is emitted in a predetermined area, the graphic unit 100a uses the area color method in the organic electroluminescent display according to the present invention. In the case of, the patterning does not need to be performed for each color area, and thus, the manufacturing cost can be reduced and an excellent effect can be obtained in terms of power consumption.

According to the experiment, in the absence of the optical resonant layer 20, Alq ₃ 50 nm doped with NPB 50 nm as a hole transporting layer and 1% Cumarine 6 as a light emitting layer on the first electrode layer of 150 nm thick ITO, Alq ₃ as an electron transporting layer The light efficiency when LiF2nm and Al100nm were formed as 30 nm and a 2nd electrode layer was 7 Cd / A.

However, according to an experiment on the organic light emitting display device according to the present invention, 70 nm of TiO ₂ is deposited between the first electrode layer of ITO and the substrate in the graphic unit 100a, and as a hole transport layer on the first electrode layer. The light efficiency was 9 Cd / A when NPB 50 nm, Alq ₃ 50 nm doped with Coumarin 6 1% as the light emitting layer, Alq ₃ 30 nm as the electron transporting layer, LiF 2 nm and Al 100 nm as the second electrode layer were formed. Accordingly, it can be seen that the optical efficiency is greatly improved by the optical resonant layer 20 in the graphic unit 100a.

In the organic electroluminescent device having the above structure, the light emitted from the organic film 13 is projected in the direction of the transparent substrate 10 to implement an image, but the present invention is not limited thereto, and the organic film 13 The same applies to the case where the light emitted from the () is projected in the direction of the seal 15. In this case, the first electrode layer is made of aluminum, and the second electrode layer is made of transparent ITO. The sealing unit 15 may be formed of a transparent substrate or a resin material of a transparent material. Of course, the optical resonant layer 20 is interposed between the sealing part 15 and the second electrode layer 14 at this time.

On the other hand, the optical resonant layer of the above principle is an organic electroluminescent display of the AM (Active Matrix) driving method, which is an organic electroluminescent device according to another preferred embodiment of the present invention as shown in Figure 3 and 4 The same can be applied to the apparatus.

First, referring to FIG. 3, in the AM driving organic light emitting display device, a thin film transistor is stacked on the transparent substrate 30. Although not shown, a buffer layer made of SiO ₂ is further provided on the surface of the transparent substrate 30 to planarize the substrate 30 and block impurities.

The p-type or n-type semiconductor layer 32 arranged in a predetermined pattern on the transparent substrate 30 is buried by the gate insulating layer 33. A gate electrode layer 34 corresponding to the semiconductor layer 32 is formed on the upper surface of the gate insulating layer 33, and the gate electrode layer 34 is buried by the first insulating layer 35. In addition, contact holes 36a and 37a are formed in the first insulating layer 35 and the gate insulating layer 33 so that the drain electrode 36 and the source electrode 37 formed on the first insulating layer 15 are formed. It is connected to both sides of the semiconductor layer 22 through the contact holes 36a and 37a to form a thin film transistor. The first auxiliary electrode 43b formed on an upper surface of the first insulating layer 35 and opposite to the first auxiliary electrode 43b is connected to the source electrode 37 next to the thin film transistor. A capacitor 43 formed of the second auxiliary electrode 43a buried in the insulating film 35 is formed to form a driving region together with the thin film transistor.

A second insulating film 38 is formed on the top surface of the first insulating film 35, and a first electrode layer 39 electrically connected to the drain electrode 36 is formed on the top surface of the second insulating film 38. . The first electrode layer 39 is formed of ITO, the planarization film 40 having the opening 40a formed on the first electrode layer 39, and the first electrode layer on the bottom surface of the opening of the planarization film 40 ( An organic layer 41 is stacked on the upper portion of the second layer 39, and a second electrode layer 42 is formed on the organic layer and the planarization layer to form a pixel area.

In the bottom emission type organic EL device as described above, the first electrode layer 39 is made of ITO which is a transparent conductive material, and the gate insulating layer 33 and the first and second insulating layers 35 and 38 are also transparent SiO. ₂ and the like. Since the organic layer 41 and the second electrode layer 42 are also the same as in the above-described embodiment, a detailed description thereof will be omitted. An upper portion of the second electrode layer 42 is provided with a sealing part (not shown) and sealed.

In the AM type organic light emitting display device, the light emitted from the organic layer 41 is emitted through the transparent substrate 30. In this case, as described above, the graphic unit 100a uses the transparent substrate 30. ) And the photonic resonant layer 20 of the present invention are formed between the gate insulating layer 33. In this optical resonant layer 20, it is preferable that a dielectric layer 20a having a small refractive index is formed on the light emitting direction side and a dielectric layer 20b having a large refractive index on the opposite side to the light emitting direction. In this case, light that leaks beyond the critical angle among the light traveling from the high refractive index second dielectric layer 20b to the low refractive index first dielectric layer 20a is totally reflected on the high refractive index second dielectric layer 20b and then Reflected by the second electrode layer 42 again, the phase with the light reflected at the interface between the first electrode layer 41 / optical resonant layer 20 and the transparent substrate 30 / optical resonant layer 20 in the same principle. If this is matched, the light amplified by the transparent substrate 30 is caused by constructive interference with each other, thereby increasing the light extraction efficiency.

In order to cause constructive interference between unreflected light, reflected light, and re-reflected light, the optical distance between the second electrode layer 42 and the optical resonant layer 20 is determined by the light emitted from the light emitting layer. It is preferable that N / 2 times (N is an integer) of the optical distance of a wavelength.

According to a preferred embodiment of the present invention, the optical resonant layer 20 is formed of a transparent or translucent first dielectric layer 20a mainly composed of SiO ₂ (refractive index n = 1.53) and a first dielectric layer 20a. The transparent or translucent second dielectric layer 20b having TiO ₂ (refractive index n = 2.2) having a higher refractive index than the main component can be formed by a method such as vacuum deposition or sputtering.

The increase in light extraction efficiency may be achieved by appropriately adjusting the thickness of the optical resonant layer 20, the distance between the light emitting layer and the second electrode layer, and the number of dielectric layers.

4 illustrates another embodiment of an AM type organic electroluminescent display according to the present invention, in which light is projected in a direction of the sealing portion, that is, in a direction opposite to the substrate 30 to implement an image. At this time, as described above, the sealing portion must be made of a transparent resin material or a transparent substrate, the second electrode layer 42 is formed of ITO, and the first electrode layer 39 is formed of aluminum.

In the case of the organic light emitting display device as shown in FIG. 4, in the graphic unit 100a, the optical resonant layer 20 is formed on the second electrode layer 42. In this case, as shown in FIG. 4, the optical resonant layer 20 may be formed for each pixel with a thickness corresponding to each pixel, and may be formed entirely on the second electrode layer 42 although not shown in the drawing. .

As described above, the present invention forms an optical resonant layer in the outermost part in the light emitting direction of the organic film, so that light emitted from the organic film passes through the intermediate layer structures to compensate for the lost light loss in the final step.

According to the organic electroluminescent device of the present invention made as described above, the following effects can be obtained.

First, through the optical resonance layer having a plurality of layers having different refractive indices, it is possible to amplify the light emitted from the organic layer, thereby increasing the light extraction efficiency and improve the color purity.

Second, by not forming the optical resonant layer that micro-resonates the light emitted from the organic light emitting layer in the icon portion, but in the graphic portion having a large power consumption, it is possible to reduce the burden of manufacturing cost and improve the power consumption characteristics of the area color product. Can be.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary and will be understood by those of ordinary skill in the art that various modifications and variations can be made therefrom. Therefore, the present invention will be defined by the technical spirit of the appended claims the true technical protection scope of the present invention.

Claims (4)

An organic electroluminescent display device comprising an icon portion for outputting fixed light emission and a graphic portion for outputting variable light emission provided on a transparent substrate. Pixels of the icon portion and the graphic portion are interposed between a first electrode layer, a second electrode layer, the first electrode layer and the second electrode layer disposed on the transparent substrate, and electrically connect the first electrode layer and the second electrode layer. An organic film having a light emitting layer for emitting light by driving, The pixel of the graphic unit excluding the icon unit may further include an optical resonant layer interposed between the transparent substrate and the first electrode layer or disposed on the second electrode layer. The method of claim 1, The second electrode layer is made of a metal electrode, And the optical distance between the second electrode layer and the optical resonant layer is N / 2 times the optical distance of the light emission wavelength, where N is an integer. The method of claim 2, And the optical resonant layer is formed of at least one pair of dielectrics having different refractive indices. The method of claim 3, wherein And the optical resonant layer comprises a first dielectric layer made of TiO ₂ and a second dielectric layer made of SiO ₂ .

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