KR101595469B1 - Organic Emitting Diode Display Device - Google Patents

Abstract

The present invention relates to an organic light emitting display in which subpixels are formed with four or more primary colors and a color is provided in an organic light emitting display through structural tuning of a hole injection layer and a hole transport layer, A display device includes an anode and a cathode opposed to each other on a substrate, and a light emitting layer between the anode and the cathode, wherein the substrate is divided into a plurality of pixels in a matrix, A red light emitting sub-pixel, a green light emitting sub-pixel, a blue light emitting sub-pixel, and a first intermediate color sub-pixel that emit light of different colors of primary colors or more, Green light emitting layer, the blue light emitting sub-pixel has a blue light emitting layer, and the first halftone sub-pixel has red, Green, and blue light emitting layers, and the first intermediate color sub-pixel includes layers other than the light emitting layer formed of combinations of thicknesses different from those of the sub pixels including the same color light emitting layer .

(3-primary), 4 primary colors, 5 primary colors, a hole transport layer, a hole injection layer, a microcavity,

Description

[0001] The present invention relates to an organic light emitting display device,

[0001] The present invention relates to an organic light emitting diode (OLED) display device, and more particularly, to an organic light emitting diode display device in which a sub-pixel is formed with four or more primary colors and a color is realized in an organic light emitting display device through structural tuning of a hole injection layer and a hole transport layer .

2. Description of the Related Art In recent years, various flat panel display devices capable of reducing weight and volume, which are disadvantages of a cathode ray tube (CRT), have been developed. Such a flat panel display device includes a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) (Or an organic light-emitting diode display device (hereinafter also referred to as "organic light-emitting display device") using an electroluminescent display device (electroluminescence display device) [0003] Researches for increasing the display quality of such a flat panel display device and attempting to make it larger have been actively conducted.

Among these organic electroluminescent devices, self-luminescent devices are self-luminous devices, which have a high response speed and high luminous efficiency, brightness and viewing angle. The organic light emitting device includes a thin film transistor array portion formed on a transparent substrate, an organic EL array portion disposed on the thin film transistor array portion, and a glass cap for isolating the organic EL array portion from the external environment.

Such an organic light emitting display device is divided into a top emission and a bottom emission according to the light emitting mode. In the case of the latter bottom emission scheme, light is emitted to the TFT array side, and the transparent substrate on which the TFT array is located is deposited in the order of the thin film transistor T, the transparent anode, the bank, the organic EL layer and the cathode.

Hereinafter, a conventional OLED display will be described with reference to the accompanying drawings.

1 is a schematic plan view showing one pixel of a conventional organic light emitting diode display.

1, one pixel of a conventional organic light emitting diode display includes R, G, and B sub-pixels including red, green, and blue light emitting layers between an anode (not shown) and a cathode Gather together.

In this case, the R light emitting layer (red light emitting layer), the G light emitting layer (green light emitting layer), and the B light emitting layer (blue light emitting layer) are formed in the sub pixels of each pixel, and between the respective light emitting layers and the anode, A hole injecting layer and a hole transporting layer are formed, and an electron transporting layer and an electron injecting layer are formed between the cathodes in the light emitting layer.

In general, the R, G, and B emissive layers have the same planar size, are spaced at equal intervals, and the gray scale voltages are applied to the corresponding sub-pixels according to the operation of the driving thin film transistor connected to each emissive layer, A predetermined color is displayed on the display surface of the organic light emitting display device according to the color combination of the B light emitting layer.

However, the above-described R, G, and B light emitting layers emitting light of red, green, and blue wavelengths have difficulties in full-color display due to the fact that the luminance of light generated is different even when the same current flows in the forward direction .

In addition, human beings have a color gamut having a visual preference. Therefore, it is difficult to meet the visual color preference merely by the three primary color luminescent layers, and it is difficult to display the natural color. It is being considered.

The conventional OLED display has the following problems.

First, in a conventional organic light emitting display device in which a three-color light emitting layer is implemented as a sub-pixel having the same plane area, and a common layer is applied above and below the light emitting layers, display of natural color is limited, There is a problem that is difficult to do.

Secondly, there is a need to develop an additional color light emitting material for color display expansion. This is due to limitations in the development of a new material, and due to the nature of the organic light emitting display that emits itself, Development requires a lot of time and effort.

Third, there is a trade-off relationship between the efficiency and the lifetime due to the improvement in color characteristics, so that only one side can be considered. That is, the improvement of the color characteristics necessarily brings about a problem of deterioration of the lifetime, and it is generally known that the improvement of the color characteristic brings about a decrease in the life and the yield.

Fourthly, there is a liquid crystal display device as compared with the organic light emitting display described above. In this case, in order to extend the color display, color display of quad or more is realized by developing a material of the color filter, Additional processing, material and process costs are essential. That is, it is necessary to develop an independent color filter material, and the increase in the number of pixels means addition of a color filter process, which may cause deterioration in mass production, and it is difficult to expand the color display.

SUMMARY OF THE INVENTION The present invention has been devised to solve the above-mentioned problems, and it is an object of the present invention to provide an organic light emitting display device, which comprises sub-pixels of four or more primary colors and structurally tunes a hole injection layer and a hole transport layer, A display device is provided.

According to an aspect of the present invention, there is provided an organic light emitting diode display comprising a substrate, a cathode and a cathode opposing each other, and a light emitting layer between the anode and the cathode, A green light emitting sub-pixel, a blue light emitting sub-pixel, and a first halftone sub-pixel that emit light of four or more primary colors for each pixel, the red light emitting sub-pixel being divided into a plurality of pixels on a matrix, The sub-pixel has a red light emitting layer, the green light emitting sub-pixel has a green light emitting layer, the blue light emitting sub-pixel has a blue light emitting layer, and the first halftone sub-pixel has a light emitting layer of the same color as red, And the first intermediate color sub-pixel has a thickness different from that of the sub-pixel including the light emitting layer of the same color A light emitting layer composed of a combination thereof, or upper and lower peripheral layers thereof.

The peripheral layers include a hole transporting layer and a hole injecting layer between each of the light emitting layers and the anode, and an electron transporting layer and an electron injecting layer between each of the light emitting layers and the cathode.

The first and second halftone sub-pixels emit green and blue halftone colors. The first halftone sub-pixel includes the green emission layer, and the green sub-pixel is formed by a combination of the thicknesses of the electron injection layer, the electron transport layer, the hole transport layer, and the hole injection layer located above and below the green emission layer, . At this time, in the green sub-pixel and the first halftone sub-pixels, hole transport layers and hole injection layers having different thickness combinations are arranged. In this case, the sum of the hole transporting layer and the hole injection layers is preferably 200 to 1000 ANGSTROM.

Further, the sub-pixels may further include a second halftone light emitting sub-pixel that emits red and blue halftone colors. Here, the second light emitting sub-pixel includes a red light emitting layer, and a combination of the red sub-pixel and the red light emitting layer has different thicknesses of the cathode, the electron injecting layer, the electron transporting layer, the hole transporting layer, Lt; / RTI > At this time, in the red sub-pixel and the second halide light-emitting sub-pixels, hole transport layers and hole injection layers having different thickness combinations may be arranged.

In addition, the area of the sub-pixels may be adjusted so that white light is emitted when the maximum output of the light-emitting layers formed in sub-pixels of different colors in each pixel is made.

On the other hand, a reflective layer may be further disposed between the substrate and the anode.

The organic light emitting display of the present invention as described above has the following effects.

First, it is possible to maximize the color expressing power of the organic light emitting display device by increasing the area of the color coordinates by adjusting the thickness of the layers formed before and after the light emitting layer such as the hole transporting layer and the hole injection layer without including the additional light emitting layer .

Second, the color reproduction ratio according to the hue of the color of the three primary colors is expressed by adjusting the thickness of the layers before and after the light-emitting layer so that the intermediate color of the three primary colors can be expressed. Do.

Third, by widening the area of the color coordinate system and making the color area more natural and user-preferred wide, the application can be used as an application meeting the needs of professionals, and the range of using the organic light emitting display device can be extended.

Hereinafter, the organic light emitting diode display of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a schematic plan view showing one pixel of an organic light emitting display according to a first embodiment of the present invention. FIGS. 3A and 3B are cross-sectional views of a pixel of an OLED display according to a first embodiment of the present invention, Sectional view showing a G sub-pixel and a GB sub-pixel, respectively.

2, one pixel of the OLED display according to the first embodiment of the present invention includes R sub-pixels (hereinafter referred to as red sub-pixels), G sub-pixels (hereinafter, referred to as green sub-pixels) , A first intermediate gray sub-pixel), and a B sub-pixel (hereinafter, a blue sub-pixel).

Here, the first halftone sub-pixel emits green and blue halftone colors and emits red, green, and blue corresponding colors to the remaining sub-pixels. That is, one pixel of the organic light emitting display according to the first embodiment of the present invention includes different sub-pixels of four primary colors having a function of emitting light of different colors.

3A and 3B, an organic light emitting display according to a first embodiment of the present invention includes a substrate 100, an anode 120 and a cathode 180 facing each other in each sub-pixel, And an emission layer 150 and 150a between the anode 120 and the cathode 180 to emit light of a corresponding color. A reflective layer 110 may be disposed between the substrate 100 and the anode 120 to perform top emission and may include a reflective metal layer 120 on the anode 120, And the bottom emission may be performed by omitting the reflective layer 110. [

The hole transport layers 140a and 140b and the hole injection layers 130a and 130b are sequentially stacked from top to bottom between the light emitting layers 150 and 150a and the anode 120. The light emitting layers 150 and 150a, The electron transport layer 160 and the electron injection layer 170 are sequentially stacked from bottom to top.

In this case, in the first embodiment, sub-pixels for emitting green and blue halftone colors are included in the first half-tone sub-pixel in addition to the three primary colors of red, blue and green. In this case, For example, a green light emitting layer is used as the light emitting layer, and the green light emitting layer or the hole transporting layer, the hole injecting layer, and the electron transporting layer located above and below the green light emitting layer, The combination of the thicknesses of the transport layer, the electron injection layer, and the cathodes is different from that of the original green light emitting layer.

In the following Tables 2 and 3, examples in which the thicknesses of the hole transport layer (HTL) and the hole injection layer (HIL) are differently combined to realize an intermediate color between green and blue by using a green light emitting layer, It is not possible to realize the first halftone color only by controlling the thickness of the injection layer, but it is also possible to change the emission period by adjusting the thickness of the layers around the light emitting layer, the electron injection layer and the electron transport layer.

3A and 3B, the hole transport layer 140a and 140b and the first sub-pixel 140b are arranged in the order of the first sub-pixel and the second sub-pixel. The thicknesses of the hole injection layers 130a and 130b are different from each other. Thus, the microcavity effect by the layers is applied differently, thereby emitting light of different colors.

The green sub-pixel (G-sub-pixel) and the green-blue sub-pixel (GB sub-pixel) are shown to have a small area on a relatively flat surface. Since the white light must be realized when there is a maximum output of both the pixels and the first halftone sub-pixels, due to the provision of the first halftone sub-pixel implemented as a relatively green light emitting layer, The sizes of the pixels must be small so that the white color can be realized by the total sum of the light amounts of these sub-pixels. If each sub-pixel has the same area, the white color can be observed more deflected by the green light in the case of the maximum output of each sub-pixel.

In addition, in the first embodiment, the first halftone sub-pixel is for realizing a color expressed only by R-G-B closer to a natural color, and is an element for further expanding the color display area.

The red sub-pixel, the green sub-pixel, the blue sub-pixel, and the first halftone sub-pixels are defined by different shadow masks, and the layers having different thicknesses of the first halo- It is possible to selectively form only the first halftone sub-pixel with a different thickness by using a shadow mask used for forming the light emitting layer of the first halftone sub-pixel or by using a new mask.

4 is a graph showing the color coordinates of the organic light emitting diode display of the present invention.

Referring to FIG. 4 and Table 1, it can be seen that the peak of blue is (0.1235, 0.0961) in the CIE-xy chromaticity coordinate system, the peak of green is (0.2114, 0.6884) in the CIE- (0.6605, 0.3375) in the CIE-xy color coordinate system.

Accordingly, in the first embodiment described above, it can be seen that the first intermediate color is the A region, which is the midpoint region between the green and blue color coordinates, when the emission color of the sub-pixel is represented by the CIE-xy color coordinates.

 Thicknesses of the hole injection layer (HIL) and the hole transport layer (HTL), which are not illustrated in Table 1, are selected to optimally emit light of the respective colors, but they can be changed within a range of ± 200 Å from the indicated values.

In the first embodiment of the present invention, the light emitting layer of the first intermediate gray sub-pixel is the same as that of the green sub-pixel, and the hole injection layer HIL ) And the hole transport layer (HTL) in the first intermediate color sub-pixel.

In Table 2, the total thickness of the hole injection layer (HIL) and the hole transport layer (HTL) is set to 2800 Å, the hole injection layer (HIL) is increased from 100 Å to 100 Å, and the hole transport layer (HTL) And the CIE xy color coordinates are measured and measured in the corresponding thickness combinations.

Here, the color coordinates vary from (0.1361, 0.4082) to (0.1388, 0.4167). It can be seen that these color coordinates are all located in the A region, which is an intermediate point between blue and green in FIG.

Table 3 below shows the relationship between the total thickness of the hole injection layer (HIL) and the hole transport layer (HTL) of 700 ANGSTROM and the hole injection layer (HIL) of 100 ANGSTROM And the hole transport layer (HTL) is decreased from 600 ANGSTROM to 100 ANGSTROM by measuring the CIE xy chromaticity coordinates in the corresponding thickness combinations.

Here, the color coordinates vary from (0.1449, 0.3976) to (0.1335, 0.4154). It can be seen that these color coordinates are all located in the A region, which is the middle point between blue and green in FIG.

The thicknesses of the hole injecting layer and the hole transporting layer may be varied within the range of 200 to 2000 ANGSTROM of the thicknesses of the hole injecting layer and the hole transporting layer .

In this case, both of the conditions shown in Table 2 and Table 3 are suitable for emitting light of the first halftone color (the intermediate color of blue and green) in the first halftone sub-pixel, while in Table 2, the thickness of the hole transport layer When the organic light emitting display device has a stacked structure, it may not adversely affect the electrical characteristics. Therefore, it is not highly recommended, and as shown in Table 3, It is preferable to use the light emitting layer of the sub pixel as the green light emitting layer.

For example, in the first halftone sub-pixel, the sum of the thicknesses of the hole transporting layer and the hole injection layer may be adjustable in the range of 200 to 1000 ANGSTROM including the range shown in Table 3. [

As described above, by using the material of the light emitting layer already contained in the three primary colors as it is, without using an additional color light emitting layer according to the first embodiment of the present invention, .

In this case, the layers around the light emitting layer of the first halftone sub-pixel are adjusted to have different thicknesses. In the definition of the first halftone sub-pixel, structural tuning using the effect of a micro- ≪ / RTI > without changing or adding material. This makes it possible to create a color corresponding to the extended color gamut, thereby realizing a more natural color display.

In the extreme case of microcavity, the light is confined between the lower reflective layer 110 and the cathode 180 of the reflective electrode (MgAg) located at the upper part, and the light is emitted only under specific conditions (wavelength of light generated in the light emitting layer and thickness of the organic material) Lt; / RTI >

In other words, adjusting the thickness of the hole transport layer (HTL) and the hole injection layer (HIL) controls the distance between the reflective layer 110 and the cathode 180 to emit only desired light to the outside, It is intended to emit light with shifted raster color.

In addition, it is possible to manufacture an application which can be used for professional use by further strengthening the color expressive power which is an advantage of self-emission.

As can be seen from FIG. 4, the A region is located outside the triangles drawn during the self-emission of the general R, G, and B emissive layers, .

The second embodiment will be described below.

FIGS. 5A and 5B are schematic plan views showing one pixel of the organic light emitting diode display according to the second embodiment of the present invention and its modified examples. FIGS. 6A and 6B are views showing the organic light emitting display according to the second embodiment of the present invention, Sectional view showing an R sub-pixel and an RB sub-pixel, respectively, in one pixel of the device.

The second embodiment, which will be described later, is intended to realize five primary colors. In addition to the first embodiment described above, a second intermediate color is to be further implemented.

5A, one pixel of the OLED display according to the second embodiment of the present invention includes R sub-pixels (hereinafter referred to as red sub-pixels), G sub-pixels (hereinafter, referred to as green sub-pixels) , A first sub-pixel (first sub-pixel), a second sub-pixel (first sub-pixel), and an RB sub-pixel (hereinafter referred to as a second sub-pixel).

Here, the first halftone sub-pixel emits green and blue halftone colors, the second halftone sub-pixel emits red and blue halftone colors, and the remaining sub-pixels emit corresponding colors of red, green, and blue do. That is, one pixel of the organic light emitting display according to the second embodiment of the present invention includes different sub-pixels of five primary colors having a function of emitting light of different colors.

5A shows an example in which each sub-pixel is positioned in the vertical direction and the area of each of the sub-pixels is different. FIG. 5B shows a blue light-emitting layer which is not used as a light- Only the blue sub-pixels including the blue sub-pixels are longitudinally formed, and the remaining sub-pixels are arranged with the vertical length halved to the blue sub-pixels.

 In FIGS. 5A and 5B, the red sub-pixel, the green sub-pixel, the blue sub-pixel and the first halftone sub-pixel in one pixel are shown as having a small area on a plane, Due to the fact that the white light must be realized when there is a maximum output of all the second halftone sub-pixels, due to the presence of the first halftone sub-pixel embodied as a green light emitting layer and the second halftone sub- The size of the remaining sub-pixels except for the blue sub-pixels must be small so that the white can be implemented by the total sum of the light amounts of the sub-pixels. If each sub-pixel has the same area, the white color can be observed more deflected with green or red light in case of the maximum output of each sub-pixel.

The sectional views of the green subpixel and the first halftone subpixel are the same as those of FIGS. 3A and 3B, and the red subpixel and the second halftrop subpixel are described below with reference to FIGS. 6A and 6B.

The organic light emitting display according to the second embodiment of the present invention includes an anode 120 and a cathode 180 opposed to each other on the substrate 100 and a cathode Emitting layer 250 and 250a for emitting light of a corresponding color between the light-emitting layers 250 and 250a. A reflective layer 110 may be disposed between the substrate 100 and the anode 120 to perform top emission and may include a reflective metal layer 120 on the anode 120, And the bottom emission may be performed by omitting the reflective layer 110. [

The hole transport layers 240a and 240b and the hole injection layers 230a and 230b are sequentially stacked from top to bottom between the light emitting layers 250 and 250a and the anode 120. The light emitting layers 250 and 250a, The electron transport layer 160 and the electron injection layer 170 are sequentially stacked from bottom to top.

In this case, in the second embodiment, sub-pixels for light emission of green and blue halftone colors are included in the first, second, and third sub-pixels in addition to the three primary colors of red, Pixel includes sub-pixels for light emission of red and blue halftone. In this case, the first halftone sub-pixel is not provided with a light-emitting layer for emitting light of the neutral color, The hole injection layer 130b, the electron transport layer 160, the electron injection layer 170, and the cathode 180 are formed on the green light emitting layer 150a or the upper and lower portions of the green light emitting layer 150a using the light emitting layer 150a as the light emitting layer. (FIG. 3A), and the second intermediate color sub-pixel uses the same red light-emitting layer 250a as the red sub-pixel, as shown in FIG. 6B, The red light emitting layer 250a The combination of the thicknesses of the hole transport layer 240b, the hole injection layer 230b, the electron transport layer 160, the electron injection layer 170 and the cathodes 180 located above and below the red light emitting layer 250) and its surrounding layers.

In Table 4, an example in which the thickness of the hole transport layer (HTL) and the hole injection layer (HIL) are differently combined to implement the second halftone sub-pixel that emits light in the red and blue halftone colors by using the red light emitting layer The second intermediate color can be realized by controlling only the thickness of the hole transport layer and the hole injection layer, but the thickness of the layers around the light emitting layer, the electron injection layer or the electron transport layer, the light emitting layer itself, The light emitting period can be extended to the intermediate color region of red and blue, that is, the region B in Fig.

Table 4 below shows the total sum of the total thickness of the hole injection layer (HIL) and the hole transport layer (HTL) of 900 ANGSTROM and the hole injection layer (HIL) of 300 ANGSTROM And the hole transport layer (HTL) is decreased from 600 ANGSTROM to 100 ANGSTROM by measuring the CIE xy chromaticity coordinates in the corresponding thickness combinations.

Here, the color coordinates change from (0.4402, 0.1883) to (0.4277, 0.1915). It can be seen that these color coordinates are all located in the region B, which is the middle point between blue and red in FIG.

The thicknesses of the hole injection layer and the hole transporting layer can be changed within a range of 200 to 2000 Å in terms of the thickness of the hole injection layer and the hole transporting layer. Do. And preferably in the range of 200 to 1000 angstroms.

7 is a schematic plan view showing one pixel of an OLED display according to a third embodiment of the present invention.

FIG. 7 is a pixel showing an organic light emitting diode display according to a third embodiment of the present invention, in which a red sub-pixel, a green sub-pixel, a blue sub-pixel, a first halftone sub- 3 sub-pixels. Here, the first and second halftone sub-pixels are as described above, and the third halide sub-pixel is a pixel emitting red and green halftone.

In this third embodiment, the third neutral gray sub-pixel is formed by selecting one of the red light emitting layer and the green light emitting layer as a light emitting layer, and differently from the first and second halftone sub pixels described above, To realize an intermediate color by the micro cavity according to the thickness.

8 is a graph showing a comparison between the color coordinate positions according to the first and second embodiments of the organic light emitting diode display of the present invention and the case of implementing the three primary color sub-pixels.

FIG. 8 is a diagram showing the first embodiment (the color of the temple) of the organic light emitting display according to the present invention and the second embodiment (the five primary colors). In comparison with the three primary color coordinates drawn in a triangle, In the embodiment, it is confirmed that the color coordinates extend from the neutral region between blue and green to the outer region of the color coordinates of the three primary colors. In addition, in the second embodiment, a color coordinate expansion I can confirm that this happened.

In this case, in the experiment using the known red, green, and blue light emitting materials, the color reproduction ratio was 93.8% when the three primary colors were reproduced, and the 100.8% color reproduction was improved when the four primary colors were reproduced. It can be seen that when the color reproduction is performed with five primary colors, the color reproduction rate is 109.3%. That is, the color reproduction improvement can be confirmed by adding sub-pixels of different colors that implement one pixel.

The result of FIG. 8 described above is made of an organic light emitting material which is not optimized in the top emission method, and is expected to have a color reproduction ratio of 130% or more when the optimally organic material is selected.

9A and 9B are graphs showing color coordinates of a general NTSC system, and FIGS. 10A and 10B are graphs showing representative natural color distributions in a CIE-xy coordinate system and a representative preferred color distribution in a CIE-xy coordinate system, respectively.

FIG. 9 shows an RGB area band in a general NTSC system. In an analog display realized with general three primary colors, a display range is a triangle deflected to the upper left side in the horseshoe It is mine.

FIG. 10A shows a grass color, a skin color, a pink color, and a marine color area, which are preferred colors of a human being. As shown in FIG. 10A, green, pink, and marine color areas exist in the three- .

Fig. 10B shows an increased color coordinate in a color distribution display in a natural world. The organic light emitting display device of the present invention makes it possible to display a color gamut by dividing one pixel into four or more primary colors.

In general organic light emitting display devices, a deep color material is developed or a color recall ratio is improved by using a micro cavity. However, in order to improve the color reproduction ratio far from the natural color, Maintaining color reproduction rate is important.

That is, the organic light emitting display device of the present invention aims at improving a color expressive power based on the proposed new color gamut which merely reflects a human visual preference while avoiding a numerically large color gamut.

At this time, the micro cavity effect according to the thickness of each layer can be shortened by verifying in advance through optical simulation.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

1 is a schematic plan view showing one pixel of a conventional organic light emitting display

2 is a schematic plan view showing one pixel of an OLED display according to a first embodiment of the present invention;

FIGS. 3A and 3B are cross-sectional views showing a G sub-pixel and a G-B sub-pixel, respectively, in one pixel of the organic light emitting diode display according to the first embodiment of the present invention;

4 is a graph showing the color coordinates of the organic light emitting display device of the present invention

5A and 5B are schematic plan views showing one pixel of an organic light emitting display according to a second embodiment of the present invention and its modified examples;

6A and 6B are cross-sectional views each showing an R sub-pixel and an R-B sub-pixel in one pixel of an OLED display according to a second embodiment of the present invention;

7 is a schematic plan view showing one pixel of an OLED display according to a third embodiment of the present invention.

8 is a graph showing a color coordinate position according to the first and second embodiments of the organic light emitting diode display of the present invention and a graph

9 is a graph showing a color coordinate of a general NTSC system

10A and 10B are graphs showing representative representative color distributions in the CIE-xy coordinate system and representative natural color distributions in the CIE-xy coordinate system, respectively

Description of the Related Art [0002]

100: substrate 110: reflective layer

120: anode 130, 130a, 230, 230a: hole injection layer

140, 140a, 240, and 240a: a hole transport layer 150: a G light emitting layer

150a: first intermediate color light emitting layer 160: electron transporting layer

170: electron injection layer 180: cathode

250: R light emitting layer 250a: second intermediate color light emitting layer

Claims (11)

An organic light emitting diode display comprising an anode and a cathode opposed to each other on a substrate and a light emitting layer between the anode and the cathode, The substrate includes a red light emitting sub-pixel, a green light emitting sub-pixel, a blue light emitting sub-pixel, and a first halftone sub-pixel, which are divided into a plurality of pixels on a matrix and emit light of four or more primary colors per pixel, , The green light emitting sub-pixel has a green light emitting layer, the blue light emitting sub-pixel has a blue light emitting layer, and the first halftone sub-pixel has the same material as any one of red, green and blue light emitting layers, Emitting layer, Wherein the first intermediate color sub-pixel includes a light emitting layer and a peripheral layer which are formed by combinations of thicknesses different from those of sub-pixels including a light emitting layer of the same material. The method according to claim 1, The perimeter layers, A hole transporting layer and a hole injecting layer between each of the light emitting layers and the anode, And an electron transport layer and an electron injection layer between each of the light emitting layers and the cathode. 3. The method of claim 2, And the first intermediate color sub-pixel emits the intermediate color of green and blue. The method of claim 3, wherein The first intermediate color sub-pixel includes the green light emitting layer. The green sub-pixel includes a combination of the thicknesses of the cathode, the electron injection layer, the electron transport layer, the hole transport layer, and the hole injection layer, And the organic light emitting display device. 5. The method of claim 4, In the green sub-pixel and the first halftone sub-pixels, Wherein a hole transport layer and a hole injection layer of different thickness combinations are arranged. 6. The method of claim 5, Wherein a sum of the hole transport layer and the hole injection layer is 200 to 1000 ANGSTROM. 5. The method of claim 4, Wherein the sub-pixels further include a second intermediate-color light-emitting sub-pixel that emits red and blue halftone colors to the sub-pixels. 8. The method of claim 7, The second light emitting sub-pixel includes a red light emitting layer, Wherein the red sub-pixel is formed by a combination of different thicknesses of a cathode, an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer disposed above and below the red light emitting layer. 9. The method of claim 8, In the red sub-pixel and the second halide light-emitting sub-pixels, Wherein a hole transport layer and a hole injection layer of different thickness combinations are arranged. delete The method according to claim 1, Further comprising a reflective layer between the substrate and the anode.

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