KR102505166B1 - Organic light emitting display device - Google Patents

Abstract

In order to provide an organic light emitting display device with improved light emitting efficiency and viewing angle, the present invention provides a first light emitting material layer disposed between first and second electrodes and commonly disposed in first to third subpixels. a second stack disposed between the stack and the first and second electrodes and including a red light emitting material layer, a green light emitting material layer, and a blue light emitting material layer respectively disposed in the first to third subpixels; An organic light emitting display device including a charge generation layer disposed between two stacks is provided.

Description

Organic light emitting display device {Organic light emitting display device}

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device having improved luminous efficiency and viewing angle.

Currently, flat panel display devices such as plasma display panel (PDP), liquid crystal display device (LCD), and organic light emitting display device (OLED) are widely researched and used. .

Among the above flat panel display devices, the organic light emitting display device is a self-emitting device, and since it does not require a backlight used in a liquid crystal display device, it can be lightweight and thin.

In addition, it has excellent viewing angle and contrast ratio compared to liquid crystal displays, is advantageous in terms of power consumption, can be driven at low DC voltage, has a fast response speed, is resistant to external shocks because the internal components are solid, and has a wide operating temperature range. It has advantages.

In particular, since the manufacturing process is simple, there is an advantage in that production costs can be significantly reduced compared to conventional liquid crystal display devices.

Such an organic light emitting display device displays an image by an organic light emitting phenomenon of an organic light emitting diode.

1 is a band diagram of a general organic light emitting diode.

As shown in the drawing, the organic light emitting diode 1 has a first electrode 11 and a second electrode 19, and a hole transport layer positioned between the first and second electrodes 11 and 19. : HTL) 13, an electron transport layer (ETL) 15, a hole transport layer 13, and an emission material layer (EML) 14 interposed between the electron transport layer 15.

In addition, in order to improve luminous efficiency, a hole injection layer (HIL) 12 is interposed between the first electrode 11 and the hole transport layer 13, and the second electrode 19 and the electron transport layer 15 ) An electron injection layer (EIL) 16 is interposed between them.

In the organic light emitting diode 1, when positive (+) and negative (-) voltages are applied to the first electrode 11 and the second electrode 19, respectively, the holes of the first electrode 11 and the second electrode The electrons of (19) are transported to the organic light emitting layer 14 to form excitons, and when these excitons transition from an excited state to a ground state, light is emitted in the form of visible light.

2 is a diagram illustrating a sub-pixel structure of a conventional organic light emitting display device.

As shown in the figure, the conventional organic light emitting display device 10 has first and second electrodes 11 and 19 facing each other and first to second electrodes 11 and 19 between the first and second electrodes 11 and 19. A red light emitting material layer 14a, EML(R), a green light emitting material layer 14b, EML(G), and a blue light emitting material layer 14c, EML(B) disposed in the third sub-pixels SP1 to SP3, respectively. ).

In addition, the hole injection layer 12 (HIL) disposed on the first electrode 11, the hole transport layer 13 (HTL) disposed on the hole injection layer 12, HIL, and the red light emitting material layer 14a, EML(R)), the green light emitting material layer 14b (EML(G)) and the blue light emitting material layer 14c (EML(B)) respectively disposed on the electron transport layer 15 (ETL).

At this time, the red light emitting material layer 14a (EML(R)), the green light emitting material layer 14b (EML(G)) and the blue light emitting material layer 14c (EML(B)) are the hole transport layer 13 (HTL) and Each is disposed between the electron transport layer 15 (ETL).

In addition, the conventional organic light emitting display device 10 is a top emission method, and the organic light emitting layers included in the first to third sub-pixels SP1 to SP3 emit red (R) light and green (G) light. Light and blue (B) light are respectively emitted.

In addition, the first electrode 11, as a reflective electrode, has a three-layer structure consisting of two transparent conductive material layers and a reflective layer disposed therebetween, and is arranged in units of one sub-pixel, and one pixel is composed of first to third layers. It consists of three sub-pixels SP1 to SP3, and the first to third sub-pixels SP1 to SP3 are divided into banks (not shown).

In addition, the second electrode 19 is a transflective electrode that transmits some of the light generated in the organic light emitting layer included in the first to third sub-pixels SP1 to SP3 and reflects the remaining light.

At this time, the light reflected from the second electrode 19 is reflected again from the first electrode 11, and the light reflected from the first and second electrodes 11 and 19, respectively, constructively interferes with light having the same wavelength. The luminous efficiency of the organic light emitting display device 10 is improved by generating (hereinafter, referred to as a micro cavity).

In order to generate such microcavities, the thickness of the organic light emitting layer is an optical distance at which microcavities can occur, and the first to third subpixels SP1 to SP3 must be formed differently for each of the first to third subpixels SP1 to SP3.

For example, the thickness of the blue, green and red light emitting material layers (14c, EML(B)), (14b, EML(G)), and (14a, EML(R)) are sequentially increased, and blue, A hole injection layer (12, HIL) or a hole transport layer respectively disposed below the green and red light emitting material layers (14c, EML(B), (14b, EML(G)), and (14a, EML(R))) The thickness of (13, HTL) can be sequentially increased.

In addition, the blue, green and red light emitting material layers (14c, EML (B)), (14b, EML (G)), (14a, EML (R))), the hole injection layer (12, HIL) or the hole injection layer (12, HIL) Since the thickness of the transport layer 13 (HTL) must satisfy an optical distance at which microcavities can occur, it is formed with a relatively thick thickness.

Accordingly, in the conventional organic light emitting display device 10, as the thickness of the hole injection layer 12 (HIL) or the hole transport layer 13 (HTL) increases, luminous efficiency is reduced.

In addition, in the conventional organic light emitting display device 10, as the first electrode 11 has a three-layer structure, front luminance characteristics are improved, but luminance viewing angle and color difference characteristics are deteriorated.

The present invention is to solve the above problems, and an object of the present invention is to provide an organic light emitting display device having improved luminous efficiency and viewing angle.

The present invention for achieving the above object is a first stack including a white light emitting material layer disposed between first and second electrodes and commonly disposed in first to third subpixels; and a second stack disposed between the second electrode and including a red light emitting material layer, a green light emitting material layer, and a blue light emitting material layer respectively disposed in the first to third subpixels, and disposed between the first and second stacks. An organic light emitting display device including a charge generation layer is provided.

In addition, the first stack further includes a first hole injection layer disposed on the first electrode, a first hole transport layer disposed on the first hole injection layer, and a first electron transport layer disposed on the white light emitting material layer. And the first hole injection layer, the first hole transport layer and the first electron transport layer are commonly disposed in the first to third subpixels.

In addition, the second stack includes a second hole injection layer disposed on the charge generation layer and in the first to third subpixels, a second hole transport layer disposed on the second hole injection layer, and a red light emitting material layer; A second electron transport layer disposed on the green light emitting material layer and the blue light emitting material layer, respectively, may be further included.

In addition, the first stack includes a first hole injection layer disposed on the charge generation layer, a first hole transport layer disposed on the first hole injection layer, and a first electron transport layer disposed on the white light emitting material layer, , the first hole injection layer, the first hole transport layer, and the first electron transport layer are commonly disposed in the first to third subpixels.

In addition, the second stack includes a second hole injection layer disposed on the first electrode and in the first to third subpixels, a second hole transport layer disposed on the second hole injection layer, and a red light emitting material layer; A second electron transport layer disposed on the green light emitting material layer and the blue light emitting material layer, respectively, may be further included.

In addition, the white light emitting material layer is disposed between the first hole transport layer and the first electron transport layer, and the red light emitting material layer, the green light emitting material layer, and the blue light emitting material layer are disposed between the second hole transport layer and the second electron transport layer, respectively. .

In addition, the first and second stacks have thicknesses that generate microresonance between the first and second electrodes.

In addition, the red light emitting material layer, the green light emitting material layer, and the blue light emitting material layer have different thicknesses.

In addition, the second hole injection layers respectively disposed in the first to third subpixels have different thicknesses.

In addition, the first electrode includes first and second transparent conductive material layers and a reflective layer disposed between the first and second transparent conductive material layers.

The present invention has an effect of improving the luminance and viewing angle of an organic light emitting display device through the first stack including the white light emitting material layer.

In addition, light emitting efficiency may be improved by reducing the thickness of the second hole injection layer or the second hole transport layer included in the second stack through the first stack including the white light emitting material layer.

1 is a band diagram of a general organic light emitting diode.
2 is a diagram illustrating a sub-pixel structure of a conventional organic light emitting display device.
3 is a diagram showing a sub-pixel structure of an organic light emitting display device according to a first embodiment of the present invention.
4 is a diagram showing a sub-pixel structure of an organic light emitting display device according to a second embodiment of the present invention.

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

<First Embodiment>

3 is a diagram showing a sub-pixel structure of an organic light emitting display device according to a first embodiment of the present invention.

As shown in the drawing, the organic light emitting display device 100 according to the first embodiment of the present invention includes first and second electrodes 111 and 119 facing each other, and first to third subpixels SP1. ~ SP3) and a first stack including a white light emitting material layer 114d (EML(W)) disposed in common, and a red light emitting material layer 114a disposed in the first to third sub-pixels SP1 to SP3, respectively. , EML (R)), a second stack including a green light emitting material layer (114b, EML (G)) and a blue light emitting material layer (114c, EML (B)), and disposed between the first and second stacks. and a charge generation layer 118 (CGL).

At this time, the first and second stacks are disposed between the first and second electrodes 111 and 119 .

Meanwhile, since the charge generation layer 118 (CGL) serves to control the charge balance of the first and second stacks adjacent to each other, it is called an intermediate connector layer (ICL).

Specifically, the first stack includes the first hole injection layer 112a (HIL1) disposed on the first electrode 111, and the first hole transport layer 113a disposed on the first hole injection layer 112a (HIL1). HTL1), and a first electron transport layer 115a (ETL1) disposed on the white light emitting material layer 114d (EML(W)).

At this time, the first hole injection layer 112a, HIL1, the first hole transport layer 113a, HTL1, and the first electron transport layer 115a, ETL1 are commonly disposed in the first to third subpixels SP1 to SP3. do.

In addition, the second stack includes the second hole injection layer 112b (HIL2) disposed above the charge generation layer 118 (CGL) and the first to third subpixels SP1 to SP3, respectively, and the second hole injection layer ( The second hole transport layer 113b (HTL2), the red light emitting material layer 114a (EML(R)), the green light emitting material layer 114b (EML(G)), and the blue light emitting material layer 112b (HIL2) are respectively disposed on the top. (114c, EML (B)) includes a second electron transport layer (115b, ETL2) respectively disposed on top.

At this time, the white light emitting material layer 114d (EML(W)) is disposed between the first hole transport layer 113a (HTL1) and the first electron transport layer 115a (ETL1), and the red light emitting material layer 114a (EML(R) )), the green light emitting material layer 114b (EML(G)) and the blue light emitting material layer 114c (EML(B)) are interposed between the second hole transport layer 113b (HTL2) and the second electron transport layer 115b (ETL2). placed in each

Meanwhile, unlike the drawings, the first and second hole injection layers 112a and HIL1 and 112b and HIL2 respectively included in the first and second stacks may be omitted.

Specifically, in the organic light emitting display device 100 according to the first embodiment of the present invention, the organic light emitting layer is composed of two stacks in a top emission method. The first stack emits white (W) light, and the second stack emits red (R) light, green (G) light, and blue (B) light, respectively.

In this case, as the first stack emitting white (W) light is disposed below the second stack, the luminance of the organic light emitting display device 100 may be improved.

In addition, the first electrode 111 is a reflective electrode, comprising first and second transparent conductive material layers (not shown) and a reflective layer (not shown) disposed between the first and second transparent conductive material layers (not shown). It is done.

In this case, the first and second transparent conductive material layers (not shown) may be made of indium-tin-oxide (ITO) or indium-zinc-oxide (IZO), and the reflective layer (not shown) may be made of silver (Ag) or It may be made of an alloy in which at least one of palladium (Pd), copper (Cu), indium (In), and neodymium (Nd) is added to silver (Ag).

In addition, the first electrode 111 is disposed in units of one subpixel, and one pixel is composed of first to third subpixels SP1 to SP3, and the first to third subpixels SP1 to SP3 are It is divided into banks (not shown).

At this time, in the organic light emitting display device 100 of the present invention, even if the first electrode 110 has a three-layer structure as the first stack emitting white (W) light is disposed below the second stack, the organic light emitting display device 100 The luminance, viewing angle, and color difference characteristics of the electroluminescent display device 100 may be improved.

That is, white (W) light emitted from the first stack reduces the luminance viewing angle and color difference characteristics that appear as a reflective effect of the frontal luminance characteristic improvement of the three-layer structure of the first electrode 110 by increasing the luminance. can do.

In addition, the second electrode 119 is a transflective electrode that transmits some of the light generated in the first and second stacks and reflects the remaining light.

At this time, the light reflected from the second electrode 119 is again reflected from the reflective layer (not shown) of the first electrode 111, and the light reflected from the first and second electrodes 111 and 119, respectively, has the same wavelength. Light emitting efficiency of the organic light emitting display device 100 is improved by generating constructive interference (hereinafter, referred to as a micro cavity) between lights having .

In order to generate such a micro cavity, the thicknesses of the first and second stacks must be formed to be different for each of the first to third sub-pixel cells SP1 to SP3 as an optical distance at which a micro cavity can occur.

Accordingly, the thicknesses of the second hole injection layer 112b or HIL2 or the second hole transport layer 113b or HTL2 disposed in the first to third sub-pixels SP1 to SP3 are formed differently, and red, green and Different thicknesses of the blue light emitting material layers (114a, EML(R), 114b, EML(G), and 114c, EML(B)) are formed.

For example, by sequentially increasing the thickness of the blue, green, and red light emitting material layers (114c, EML (B), (114b, EML (G)), and (114a, EML (R))), blue, The second hole injection layer 112b (HIL2) respectively disposed under the green and red light emitting material layers (114c, EML(B), 114b, EML(G), and 114a, EML(R)), or The thickness of the second hole transport layer 113b (HTL2) may be sequentially increased.

At this time, the blue, green and red light emitting material layers (114c, EML(B)), (114b, EML(G)), (114a, EML(R))), the second hole injection layer 112b, HIL2 ) or the thickness of the second hole transport layer 113b (HTL2) is relatively thick because it must satisfy an optical distance at which microcavities can occur.

In particular, unlike the conventional organic light emitting display device (10 in FIG. 2), the organic light emitting display device 100 according to the first embodiment of the present invention arranges the first stack under the second stack, The thickness of the second stack is formed to an optical distance that generates a micro cavity, and at the same time, the second hole injection layer (112b, HIL2) or the second hole transport layer included in the second stack is as thick as the first stack. Since the thickness of (113b, HTL2) can be reduced, the luminous efficiency can be improved.

Table 1 below exemplarily shows the thickness of the hole injection layer (HIL in FIG. 2) of the conventional organic light emitting display device (10 in FIG. 2), and Table 2 shows the thickness according to the first embodiment of the present invention. The thickness and thickness of the white light emitting material layer 114d (EML(W)), the first hole transport layer 113a (HTL1), and the first hole injection layer 112a (HIL1) of the first stack of the organic light emitting display device 100 The thicknesses of the two stacks of the second hole injection layers 112b and HIL2 are respectively shown.

SP1 SP2 SP3 HIL 200㎛ 150㎛ 120㎛

SP1 SP2 SP3 2nd stack HIL2 100㎛ 50㎛ 20㎛ 1st stack EML(W) ~50㎛ HTL1 20㎛ HIL1 ~30㎛

As shown in Tables 1 and 2, the hole injection layer (HIL in FIG. 2) disposed in the first to third sub-pixels SP1 to SP3 of the conventional organic light emitting display device (10 in FIG. 2), respectively. Thicknesses are 200 μm, 150 μm, and 120 μm, respectively, and the white light emitting material layer 114d (EML(W)) of the first stack of the organic light emitting display device 100 according to the first embodiment of the present invention, the first The hole transport layers 113a and HTL1 and the first hole injection layers 112a and HIL1 have thicknesses of 50 μm, 20 μm, and 30 μm, respectively, and are applied to the first to third subpixels SP1 to SP3 of the second stack, respectively. The disposed second hole injection layers 112b and HIL2 have thicknesses of 100 μm, 50 μm, and 20 μm, respectively.

At this time, the second stack of the organic light emitting display device 100 according to the first embodiment of the present invention corresponding to the hole injection layer 12 (HIL) of the conventional organic light emitting display device (10 in FIG. 2) The second hole injection layer 112b (HIL2) has a thickness reduced by 100 μm compared to the hole injection layer (HIL) of the conventional organic light emitting display device (10 in FIG. 2).

Here, the sum of the thicknesses of the white light emitting material layer 114d (EML(W)), the first hole transport layer 113a, and the first hole injection layer 112a (HIL1) of the first stack is 100 μm, and the thickness of the second stack The reduced thickness of the second hole injection layer (112b, HIL2) is the first stack of the white light emitting material layer (114d, EML(W)), the first hole transport layer (113a, HTL1) and the first hole injection layer (112a, It is compensated through the thickness of HIL1).

5 and 6 are graphs comparing color difference and luminance according to viewing angles of a conventional organic light emitting display device according to the present invention and an organic light emitting display device according to the first embodiment.

At this time, the blue line represents the conventional organic light emitting display device, and the red line represents the organic light emitting display device according to the first embodiment of the present invention.

As shown in the figure, it can be confirmed that the organic light emitting display device according to the first embodiment of the present invention has improved color viewing angles and luminance viewing angles compared to conventional organic light emitting display devices.

<Second Embodiment>

4 is a diagram showing a sub-pixel structure of an organic light emitting display device according to a second embodiment of the present invention.

As shown in the drawing, the organic light emitting display device 200 according to the second embodiment of the present invention includes first and second electrodes 211 and 219 facing each other, and first to third subpixels SP1. ~ SP3) and a first stack including a white light emitting material layer 214d (EML(W)) disposed in common, and a red light emitting material layer 214a disposed in the first to third sub-pixels SP1 to SP3, respectively. , EML (R)), a second stack including a green light emitting material layer (214b, EML (G)) and a blue light emitting material layer (214c, EML (B)), and disposed between the first and second stacks. and a charge generation layer 218 (CGL).

At this time, the first and second stacks are disposed between the first and second electrodes 211 and 219 .

On the other hand, since the charge generation layer 218 (CGL) serves to control the charge balance of the first and second stacks adjacent to each other, it is called an intermediate connector layer (ICL).

Specifically, the first stack includes the first hole injection layer 212a (HIL1) disposed on the charge generation layer 218 (CGL), and the first hole transport layer ( 213a (HTL1) and a first electron transport layer (215a, ETL1) respectively disposed on the white light emitting material layer (214d, EML(W)).

At this time, the first hole injection layer 212a, HIL1, the first hole transport layer 213a, HTL1, and the first electron transport layer 215a, ETL1 are commonly disposed in the first to third subpixels SP1 to SP3. do.

In addition, the second stack includes second hole injection layers 212b and HIL2 respectively disposed on the first electrode 211 and on the first to third subpixels SP1 to SP3, the second hole injection layer 212b, HIL2), the second hole transport layer 213b (HTL2), the red light emitting material layer 214a (EML(R)), the green light emitting material layer 214b (EML(G)), and the blue light emitting material layer 214c. , EML (B)) includes a second electron transport layer (215b, ETL2) respectively disposed on top.

At this time, the white light emitting material layer 214d (EML(W)) is disposed between the first hole transport layer 213a (HTL1) and the first electron transport layer 215a (ETL1), and the red light emitting material layer 214a (EML(R) )), the green light emitting material layer 214b (EML(G)) and the blue light emitting material layer 214c (EML(B)) are interposed between the second hole transport layer 213b (HTL2) and the second electron transport layer 215b (ETL2). placed in each

Meanwhile, unlike the drawing, the first and second hole injection layers 212a and HIL1 and 212b and HIL2 respectively included in the first and second stacks may be omitted.

Specifically, the organic light emitting display device 200 according to the second embodiment of the present invention is a top emission method, and the organic light emitting layer is composed of two stacks. The first stack emits white (W) light, and the second stack emits red (R) light, green (G) light, and blue (B) light, respectively.

In this case, as the first stack emitting white (W) light is disposed on the second stack, the luminance of the organic light emitting display device 200 may be improved.

In addition, the first electrode 211 is a reflective electrode, comprising first and second transparent conductive material layers (not shown) and a reflective layer (not shown) disposed between the first and second transparent conductive material layers (not shown). It is done.

In this case, the first and second transparent conductive material layers (not shown) may be made of indium-tin-oxide (ITO) or indium-zinc-oxide (IZO), and the reflective layer (not shown) may be made of silver (Ag) or It may be made of an alloy in which at least one of palladium (Pd), copper (Cu), indium (In), and neodymium (Nd) is added to silver (Ag).

In addition, the first electrode 211 is arranged in units of one subpixel, and one pixel is composed of first to third subpixels SP1 to SP3, and the first to third subpixels SP1 to SP3 are It is divided into banks (not shown).

At this time, in the organic light emitting display device 200 of the present invention, even if the first electrode 210 has a three-layer structure as the first stack emitting white (W) light is disposed on the second stack, the organic light emitting display device 200 The viewing angle and color difference characteristics of the electroluminescent display device 200 may be improved.

That is, white (W) light emitted from the first stack increases the luminance to prevent the luminance viewing angle and color difference characteristics from being lowered as a reflective effect of the front luminance characteristic improvement of the three-layered first electrode 210. can do.

In addition, the second electrode 219 is a transflective electrode that transmits some of the light generated in the first and second stacks and reflects the remaining light.

At this time, the light reflected from the second electrode 219 is again reflected from the reflective layer (not shown) of the first electrode 211, and the light reflected from the first and second electrodes 211 and 219, respectively, has the same wavelength. Light emitting efficiency of the organic light emitting display device 200 is improved by generating constructive interference (hereinafter, referred to as a micro cavity) between lights having .

In order to generate such a micro cavity, the thicknesses of the first and second stacks must be formed to be different for each of the first to third sub-pixel cells SP1 to SP3 as an optical distance at which a micro cavity can occur.

Accordingly, the thicknesses of the second hole injection layer 212b or HIL2 or the second hole transport layer 213b or HTL2 disposed in the first to third sub-pixels SP1 to SP3 are formed differently, and red, green and Different thicknesses of the blue light emitting material layers (214a, EML(R), 114b, EML(G), and 114c, EML(B)) are formed.

For example, by sequentially increasing the thickness of the blue, green and red light emitting material layers (214c, EML(B)), (214b, EML(G)), and (214a, EML(R)), blue, The second hole injection layer 212b (HIL2) respectively disposed under the green and red light emitting material layers (214c, EML(B), 214b, EML(G), and 214a, EML(R)), or The thickness of the second hole transport layer 213b (HTL2) may be sequentially increased.

At this time, the blue, green and red light emitting material layers (214c, EML(B)), (214b, EML(G)), and (214a, EML(R))), the second hole injection layer 112b, HIL2 ) or the thickness of the second hole transport layer 113b (HTL2) is relatively thick because it must satisfy an optical distance at which microcavities can occur.

In particular, unlike the conventional organic light emitting display device (10 in FIG. 2), the organic light emitting display device 200 according to the second embodiment of the present invention arranges the first stack on top of the second stack, thereby providing first and second stacks. The thickness of the second stack is formed to an optical distance that generates a micro cavity, and at the same time, the second hole injection layer 212b (HIL2) or the second hole transport layer included in the second stack is as thick as the first stack. Since the thickness of (213b, HTL2) can be reduced, luminous efficiency can be improved.

Table 3 below exemplarily shows the thickness of the hole injection layer (HIL in FIG. 2) of the conventional organic light emitting display device (10 in FIG. 2), and Table 4 shows the thickness according to the second embodiment of the present invention. The thickness and thickness of the white light emitting material layer 214d (EML(W)), the first hole transport layer 213a (HTL2), and the first hole injection layer 212a (HIL1) of the first stack of the organic light emitting display device 200 The thicknesses of the two stacks of the second hole injection layers 212b and HIL2 are respectively shown.

SP1 SP2 SP3 HIL 200㎛ 150㎛ 120㎛

SP1 SP2 SP3 1st stack EML(W) ~50㎛ HTL1 20㎛ HIL1 ~30㎛ 2nd stack HIL2 100㎛ 50㎛ 20㎛

As shown in Tables 3 and 4, the hole injection layer (HIL in FIG. 2) disposed in the first to third sub-pixels SP1 to SP3 of the conventional organic light emitting display device (10 in FIG. 2), respectively. Thicknesses are 200 μm, 150 μm, and 120 μm, respectively, and the white light emitting material layer 214d (EML(W)) of the first stack of the organic light emitting display device 100 according to the first embodiment of the present invention, the first The hole transport layers 213a and HTL1 and the first hole injection layers 212a and HIL1 have thicknesses of 50 μm, 20 μm, and 30 μm, respectively, and are respectively applied to the first to third subpixels SP1 to SP3 of the second stack. The disposed second hole injection layers 212b and HIL2 have thicknesses of 100 μm, 50 μm, and 20 μm, respectively.

At this time, the second stack of the organic light emitting display device 200 according to the first embodiment of the present invention corresponding to the hole injection layer 12 (HIL) of the conventional organic light emitting display device (10 in FIG. 2) The second hole injection layer 212b (HIL2) has a thickness reduced by 100 μm from the hole injection layer (HIL) of the conventional organic light emitting display device (10 in FIG. 2).

Here, the sum of the thicknesses of the white light emitting material layer 214d (EML(W)), the first hole transport layer 213a, and the first hole injection layer 212a (HIL1) of the first stack is 100 μm, and the second stack The reduced thickness of the second hole injection layer 212b (HIL2) is the first stack of the white light emitting material layer 214d (EML(W)), the first hole transport layer 213a (HTL1) and the first hole injection layer 212a, It is compensated through the thickness of HIL1).

5 and 6 are graphs comparing color difference and luminance according to viewing angles of a conventional organic light emitting display device according to the present invention and an organic light emitting display device according to a second embodiment.

At this time, the blue line represents the conventional organic light emitting display device, and the red line represents the organic light emitting display device according to the second embodiment of the present invention.

As shown in the drawing, it can be confirmed that the organic light emitting display device according to the second embodiment of the present invention has improved color viewing angles and luminance viewing angles compared to conventional organic light emitting display devices.

The present invention is not limited to the above-described embodiments, and various changes and modifications are possible without departing from the spirit of the present invention.

111: first electrode
112a, 112b: first and second hole injection layers
113a, 113b: first and second hole transport layers
114a ~ 114d: red, green, blue and white light emitting material layers
115a, 115b: first and second electron transport layers
119: second electrode

Claims (9)

a first stack disposed between the first and second electrodes and including a white light emitting material layer commonly disposed in the first to third sub-pixels;
a second stack disposed between the first and second electrodes and including a red light emitting material layer, a green light emitting material layer, and a blue light emitting material layer respectively disposed on the first to third subpixels; and
A charge generation layer disposed between the first and second stacks
including,
The first and second stacks have a thickness that generates a microresonance between the first and second electrodes,
The second stack further includes hole injection layers respectively disposed on the first to third subpixels, and the hole injection layers have different thicknesses.
Organic light emitting display device.
According to claim 1,
The first stack is disposed between the first electrode and the charge generation layer, and the second stack is disposed between the charge generation layer and the second electrode.
According to claim 1,
The first stack is disposed between the charge generation layer and the second electrode, and the second stack is disposed between the first electrode and the charge generation layer.
delete According to claim 1,
The red light emitting material layer, the green light emitting material layer, and the blue light emitting material layer have different thicknesses.
According to claim 5,
The second stack further includes hole transport layers respectively disposed on the first to third sub-pixels, and the hole injection layers have different thicknesses.
According to claim 6,
The hole transport layer or the hole injection layer has a thickness of 20 to 100 μm.
According to claim 7,
The first electrode includes first and second transparent conductive material layers and a reflective layer disposed between the first and second transparent conductive material layers.
According to claim 1,
The first to third sub-pixels emit white light and red light, white light and green light, and white light and blue light, respectively.

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