KR102393788B1 - Organic light emitting display device - Google Patents

Abstract

The present invention relates to an organic light emitting display device in which pixels having organic light emitting diodes are arranged, and includes a first electrode of the organic light emitting diode, an antireflection layer, and a bank. An anti-reflection layer is disposed on the edge of the first electrode. The bank covers at least a portion of the antireflection layer and has an opening exposing at least a portion of the first electrode.

Description

Organic light emitting display device {ORGANIC LIGHT EMITTING DISPLAY DEVICE}

The present invention relates to an organic light emitting display device.

Various display devices capable of reducing weight and volume, which are disadvantages of a cathode ray tube, are being developed. Such display devices include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an organic light emitting display device (OLED). ) can be implemented as

Among these display devices, the organic light emitting display device is a self-luminous display device that emits light by excitation of an organic compound, and it does not require a backlight used in LCDs, so it can be lightweight and thin and has the advantage of simplifying the process. In addition, the organic light emitting display device is widely used in that it can be manufactured at a low temperature, has a response speed of 1 ms or less, has a high response speed, and has characteristics such as low power consumption, wide viewing angle, and high contrast. .

An organic light emitting diode display includes pixels having organic light emitting diodes that convert electrical energy into light energy. The organic light emitting diode includes an anode, a cathode, and an organic compound layer disposed therebetween. In the organic light emitting display device, holes and electrons respectively injected from an anode and a cathode combine in an emission layer to form excitons, which are excitons, and the formed excitons are converted from an excited state to a ground state. As it falls, it emits light to display an image.

The organic compound layer may include red (R), green (G) and blue (B) organic compound layers, which may be formed in corresponding red (R), green (G) and blue (B) pixels, respectively. For such red (R), green (G), and blue (B) pixel patterning, a fine metal mask (FMM) is generally used. However, despite the rapid development of process technology, there is a limit to using the FMM mask to implement a high-resolution display device. In fact, when an FMM mask is used to implement a resolution of 1000 PPI or higher, it is difficult to secure a process yield of a certain level or higher.

In addition, in order to realize a large-area high-resolution display device, a corresponding large-area FMM mask is required. Various defects are caused, such as failure to do so.

The present invention provides an organic light emitting display device having improved display quality by minimizing color mixing defects.

The present invention relates to an organic light emitting display device in which pixels having organic light emitting diodes are arranged, and includes a first electrode of the organic light emitting diode, an antireflection layer, and a bank. An anti-reflection layer is disposed on the edge of the first electrode. The bank covers at least a portion of the antireflection layer and has an opening exposing at least a portion of the first electrode.

In the present invention, by including the anti-reflection layer formed on the first electrode of the organic light emitting diode, color mixing defects can be minimized. Accordingly, the present invention has an advantage in that it is possible to provide an organic light emitting display device with significantly improved display quality.

1 is a plan view schematically illustrating an organic light emitting display device.
2 and 3 are cross-sectional views schematically illustrating an organic light emitting diode display.
4 is a view for explaining a problem in the bank structure having a concave portion.
5 is a block diagram schematically illustrating an organic light emitting display device according to the present invention.
6 is a configuration diagram schematically illustrating the pixel illustrated in FIG. 3 .
7 is a configuration diagram illustrating a specific example of FIG. 6 .
8 is a cross-sectional view schematically illustrating an organic light emitting display device according to a first exemplary embodiment of the present invention.
9 is a view for explaining the structure of the anti-reflection layer.
10 is a simulation result for explaining the effect of the anti-reflection layer.
11 is a view for explaining an arrangement example of an anti-reflection layer according to a second embodiment of the present invention.
12 is a view for explaining an arrangement example of an anti-reflection layer according to a third embodiment of the present invention.
13 is a view for explaining an arrangement example of an anti-reflection layer according to a fourth embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numerals refer to substantially identical elements throughout. In the following description, if it is determined that a detailed description of a known technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In describing various embodiments, the same components are representatively described in the introduction and may be omitted in other embodiments.

Terms including an ordinal number such as 1st, 2nd, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

1 is a plan view schematically illustrating an organic light emitting display device. 2 and 3 are cross-sectional views schematically illustrating an organic light emitting diode display.

1 and 2 , an organic light emitting diode display includes a display panel DIS having a plurality of pixels PXL. The display panel DIS may have various shapes. That is, the display panel DIS may have a rectangular shape or a square shape, as well as various free form planar shapes such as a circular shape, an oval shape, and a polygonal shape.

The display panel DIS includes red (R), blue (B), and green (G) pixels PXL that emit red (R), blue (B), and green (G) light, respectively. If necessary, the display panel DIS may further include a pixel PXL emitting another color, such as white W. Hereinafter, for convenience of description, a case in which the display panel DIS includes red (R), blue (B), and green (G) pixels PXL will be described as an example.

The organic light emitting display device according to the present invention includes an organic compound layer (OL) emitting white (W) and red (R) and blue (B) to realize red (R), green (G) and blue (B). B) and a color filter of green (G). That is, in the organic light emitting display device, white (W) light emitted from the organic compound layer OL is provided in regions corresponding to red (R), green (G), and blue (B) pixels PXL, respectively. By passing through the color filters of R), green (G), and blue (B), red (R), green (G), and blue (B) may be realized.

In the case of the organic light emitting display device according to the present invention, since it is sufficient to form the organic compound layer OL emitting white (W) to cover most of the entire panel surface, it is sufficient to form the red (R) and blue (B) layers. And it is not necessary to use the FMM mask to distinguish each of the green (G) organic compound layers OL and allocate them to the corresponding pixels PXL. Accordingly, the present invention is advantageous in that it is possible to prevent problems caused by using the above-described FMM, for example, a decrease in process yield when realizing high resolution, and poor alignment in which the organic compound layer (OL) is not formed in place. has

According to the present invention, by using the above-described method, it is possible to realize a display device having a high resolution while minimizing a decrease in process yield. However, due to a leakage current through the organic compound layer OL, light may be emitted from an unwanted pixel PXL, and color mixing may occur between neighboring pixels PXL. Here, at least one layer having high conductivity among the layers constituting the organic compound layer OL may serve as a flow path (LCP, FIG. 2 ) of the leakage current.

As an example, referring to FIG. 2A , the organic compound layer OL emitting white light may have a multi-stack structure such as a two-stack structure. The two-stack structure includes a charge generation layer (CGL) disposed between the first electrode E1 and the second electrode E2, and a charge generation layer (CGL) with the charge generation layer (CGL) interposed therebetween. It may include a first stack STC1 and a second stack STC2 disposed on a lower portion and an upper portion, respectively. Hereinafter, a case in which the first electrode E1 is an anode and the second electrode E2 is a cathode will be described as an example, but the present invention is not limited thereto. That is, the organic light emitting diode may be implemented as an inverted structure.

The first stack STC1 and the second stack STC2 each include an emission layer, a hole injection layer, a hole transport layer, an electron transport layer, and electrons. At least one of common layers such as an electron injection layer may be further included. The light emitting layer of the first stack STC1 and the light emitting layer of the second stack STC2 may include light emitting materials of different colors. One of the emission layer of the first stack STC1 and the emission layer of the second stack STC2 may include a blue emission material and the other may include a yellow emission material, but is not limited thereto.

Since the above-described organic compound layer OL, particularly the charge generating layer CGL, is not separated and patterned for each pixel PXL and is formed widely to cover all pixels, a portion generated when the display device maintains an on state A current may leak through the charge generation layer CGL. As light is emitted from the pixel PXL, which is not required to emit light due to the leakage current, a problem occurs in that the color gamut is significantly reduced.

As another example, referring to FIG. 2B , the organic compound layer OL emitting white (W) may have a single stack structure. Each single stack includes an emission layer (EML), a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL) and an electron injection layer ( At least one of common layers such as an electron injection layer (EIL) may be further included.

Since the aforementioned organic compound layer OL, particularly the hole injection layer HIL, is not separated and patterned for each pixel PXL, but is formed widely to cover all pixels, a portion generated when the display device maintains an on state Current may leak through the hole injection layer (HIL). As light is emitted from the pixel PXL, which is not required to emit light due to the leakage current, a problem occurs in that the color gamut is significantly reduced.

The above problem is more problematic in a high-resolution display device in which the pixel (PXL) size interval is relatively reduced. That is, although the neighboring pixels PXL are partitioned by a pixel defining layer such as the bank BN and are spaced apart from each other by a predetermined distance, the gap is significantly reduced in a high-resolution display device, so color mixing is poor due to leakage current. The frequency of occurrence is bound to increase. Therefore, it is necessary to limit the flow of leakage current in order to prevent display quality deterioration in the high-resolution display device.

In order to minimize the flow of the leakage current, a method of forming the concave portion BH on the bank BN disposed between the neighboring pixels PXL may be considered. That is, referring to FIG. 3 , the bank BN includes a concave portion BH. The concave portion BH may have a hole shape that completely penetrates the entire thickness of the bank BN to expose the lower layer, and may have a groove shape provided by being partially recessed inward from the upper surface of the bank BN. . The concave portion BH is disposed between neighboring pixels PXL in one area.

The concave portion BH may function to sufficiently secure a path of a leakage current that may flow to the neighboring pixel PXL. That is, when the concave portion BH is formed in the bank BN, a layer (eg, a charge generating layer) that serves as a flow path of the leakage current is also deposited along the step provided by the concave portion BH, A relatively long leakage current flow path can be secured. Accordingly, according to the preferred embodiment of the present invention, leakage current can be effectively blocked, thereby preventing a problem in which the color reproducibility is significantly lowered as light is emitted from pixels that do not require light emission.

In other words, in a preferred embodiment of the present invention, the surface area of a layer (for example, a charge generating layer) serving as a path of leakage current is relatively increased by providing the bank BN in which the recesses BH are formed. can That is, in a preferred embodiment of the present invention, the resistance can be increased by controlling the surface area of the layer (eg, the charge generating layer) serving as the path of the leakage current. Accordingly, since the preferred embodiment of the present invention can effectively reduce the flow of leakage current, it is possible to minimize color mixing defects due to leakage current. In order to increase the resistance by controlling the surface area, the present invention can appropriately select the number of the recesses BH, such as forming a plurality of recesses BH between neighboring pixels, and the width and depth of the recesses BH. can be appropriately selected.

4 is a view for explaining a problem in the bank structure having a concave portion.

Referring to FIG. 4 , light generated inside the organic compound layer OL is emitted in multiple directions. In order to increase the luminous efficiency of the organic light emitting diode (OLE), it is necessary to control the propagation direction of the emitted light in one predetermined direction (hereinafter referred to as the directing direction). That is, the transmissive electrode and the reflective electrode may be disposed to face each other with the organic compound layer OL interposed therebetween in order to control the propagation direction of the emitted light. In the present invention, the first electrode E1 may function as a reflective electrode, and the second electrode E2 may function as a transmissive electrode.

Some of the generated light traveling in the directing direction passes through the transmission electrode and the color filter CF and is emitted to the outside of the display device. Some other light is converted to a directing direction through the reflective electrode, and then passes through the transmitting electrode and the color filter CF in turn and is emitted to the outside of the display device. In this way, when the reflective electrode is further included, the light efficiency can be improved because the propagation direction of the lights that do not travel in the initial directing direction can be switched to the directing direction.

However, some of the light L1 emitted from the organic compound layer OL may not pass through the color filter CF assigned to the corresponding pixel, but may travel toward the neighboring color filter CF. In this case, since color mixing defects occur, the display quality is remarkably deteriorated, which is a problem. A preferred embodiment of the present invention may include a black matrix (BM) to improve the color mixing defect. Furthermore, in order to effectively improve color mixing defects by using the black matrix BM, the cell gap CG may be adjusted or the width of the black matrix BM may be appropriately adjusted.

However, some of the light emitted from the organic compound layer OL is caused by a difference in refractive index between the thin film layers provided in the light propagation path (eg, a difference in refractive index between the organic film and the inorganic film constituting the encapsulation layer ENC). It may proceed through total reflection between the interfaces of the thin film layers, and may be guided in the direction of neighboring pixels. Light wave-guided in the direction of the neighboring pixel is reflected by the first electrode E1 of the neighboring pixel and passes through the neighboring color filter CF, thereby causing color mixing defects. For example, the light L2 wave-guided in the direction of the neighboring pixel is converted by the concave portion BH provided in the bank BN while traveling on the surface and/or inside of the bank BN, so that It may be incident on the first electrode E1 and is reflected by the first electrode E1 to pass through the neighboring color filter CF, causing color mixing defects. Since the traveling direction of the light L2 is seriously deviated from the directing direction, there is a limit to blocking the light L2 using the black matrix BM.

In a high-resolution display device having a high PPI (Pixel Per Inch), since the size of a pixel is relatively reduced, color mixing due to the wave-guided light L2 may be more problematic. Accordingly, in the preferred embodiment of the present invention, a novel structure for minimizing the above-described color mixing defect needs to be proposed.

<First embodiment>

5 is a block diagram schematically illustrating an organic light emitting display device according to the present invention. 6 is a configuration diagram schematically illustrating the pixel illustrated in FIG. 3 . 7 is a configuration diagram illustrating a specific example of FIG. 6 . 8 is a cross-sectional view schematically illustrating an organic light emitting display device according to a first exemplary embodiment of the present invention. 9 is a view for explaining the structure of the anti-reflection layer.

Referring to FIG. 5 , the organic light emitting diode display 10 according to the present invention includes a display driving circuit and a display panel DIS.

The display driving circuit includes the data driving circuit 12 , the gate driving circuit 14 , and the timing controller 16 to write the video data voltage of the input image to the pixels PXL of the display panel DIS. The data driving circuit 12 converts digital video data RGB input from the timing controller 16 into an analog gamma compensation voltage to generate a data voltage. The data voltage output from the data driving circuit 12 is supplied to the data lines D1 to Dm. The gate driving circuit 14 sequentially supplies a gate signal synchronized with the data voltage to the gate lines G1 to Gn to select the pixels PXL of the display panel DIS to which the data voltage is written.

The timing controller 16 inputs timing signals such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, and a main clock MCLK input from the host system 19 . In response, the operation timings of the data driving circuit 12 and the gate driving circuit 14 are synchronized. The data timing control signal for controlling the data driving circuit 12 includes a source sampling clock (SSC), a source output enable signal (SOE), and the like. The gate timing control signal for controlling the gate driving circuit 14 includes a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal (Gate Output Enable, GOE), etc. includes

The host system 19 may be implemented as any one of a television system, a set-top box, a navigation system, a DVD player, a Blu-ray player, a personal computer (PC), a home theater system, and a phone system. The host system 19 includes a system on chip (SoC) having a built-in scaler and converts digital video data RGB of an input image into a format suitable for display on the display panel DIS. The host system 19 transmits the timing signals Vsync, Hsync, DE, and MCLK together with the digital video data to the timing controller 16 .

The display panel DIS may have various planar shapes. That is, the display panel DIS may have a rectangular shape or a square shape, as well as various free form planar shapes such as a circular shape, an oval shape, and a polygonal shape.

The display panel DIS includes a pixel array. The pixel array includes a plurality of pixels PXL. Each of the pixels PXL may be defined by an intersecting structure of data lines D1 to Dm, m is a positive integer, and gate lines G1 to Gn, n is a positive integer, but is limited thereto. not. Each of the pixels PXL includes an organic light emitting diode that is a self-emission device. The display panel DIS includes red (R), blue (B), and green (G) pixels PXL that emit red (R), blue (B), and green (G) light.

The pixel PXL may have various shapes. That is, the pixel PXL may have various planar shapes such as circular, oval, and polygonal shapes. One of the pixels PXL may have a different size and/or a planar shape than the other.

Referring further to FIG. 6 , a plurality of data lines D and a plurality of gate lines G cross each other in the display panel DIS, and pixels PXL are arranged in a matrix form in each crossed area. Each of the pixels PXL is an organic light emitting diode (OLED), a driving thin film transistor (DT) that controls the amount of current flowing through the organic light emitting diode (OLED), and gate-source voltage of the driving thin film transistor (DT). It includes a programming unit (SC) for setting.

The programming unit SC may include at least one switched thin film transistor and at least one storage capacitor. The switched thin film transistor is turned on in response to a gate signal from the gate line G, thereby applying a data voltage from the data line D to one electrode of the storage capacitor. The driving thin film transistor DT controls the amount of light emitted from the organic light emitting diode OLED by controlling the amount of current supplied to the organic light emitting diode OLED according to the level of the voltage charged in the storage capacitor. The amount of light emitted from the organic light emitting diode OLED is proportional to the amount of current supplied from the driving thin film transistor DT. The pixel PXL is connected to the high potential voltage source Evdd and the low potential voltage source Evss, and receives a high potential power voltage and a low potential power voltage from a power generator (not shown), respectively. The thin film transistors constituting the pixel PXL may be implemented as p-type or n-type. In addition, the semiconductor layer of the thin film transistors constituting the pixel PXL may include amorphous silicon, polysilicon, or oxide. Hereinafter, a case in which the semiconductor layer includes an oxide will be described as an example. The organic light emitting diode (OLED) includes an anode (ANO), a cathode (CAT), and an organic compound layer interposed between the anode (ANO) and the cathode (CAT). The anode ANO is connected to the driving thin film transistor DT.

As shown in (a) of FIG. 7 , the sub-pixel includes the aforementioned switching transistor SW, driving transistor DR, capacitor Cst and organic light emitting diode OLED as well as internal compensation circuit CC. can do. The internal compensation circuit CC may include one or more transistors connected to the compensation signal line INIT. The internal compensation circuit CC sets the gate-source voltage of the driving transistor DR to a voltage in which the threshold voltage is reflected, so that when the organic light emitting diode OLED emits light, the luminance change due to the threshold voltage of the driving transistor DR is corrected. exclude In this case, the scan line GL1 includes at least two scan lines GL1a and GL1b to control the switching transistor SW and the transistors of the internal compensation circuit CC.

As shown in FIG. 7B , the sub-pixel may include a switching transistor SW1 , a driving transistor DR, a sensing transistor SW2 , a capacitor Cst, and an organic light emitting diode OLED. The sensing transistor SW2 is a transistor that may be included in the internal compensation circuit CC, and performs a sensing operation for compensation driving of the sub-pixel.

The switching transistor SW1 serves to supply the data voltage supplied through the data line DL1 to the first node N1 in response to the scan signal supplied through the first scan line GL1a. In addition, the sensing transistor SW2 initializes or senses the second node N2 positioned between the driving transistor DR and the organic light emitting diode OLED in response to the sensing signal supplied through the second scan line GL1b. plays a role

The structure of the pixel of the present invention is not limited thereto, and may be variously configured as 2T (Transistor) 1C (Capacitor), 3T1C, 4T2C, 5T2C, 6T2C, 7T2C, or the like.

Referring to FIG. 8 , an organic light emitting diode display according to a preferred embodiment of the present invention includes a thin film transistor substrate SUB. A thin film transistor T allocated to each of the pixels and an organic light emitting diode OLE connected to the thin film transistor T are disposed on the thin film transistor substrate SUB. Neighboring pixels may be partitioned by a bank BN (or a pixel defining layer), and a planar shape of each pixel PXL may be defined by a bank BN. Accordingly, in order to form the pixels PXL having a preset planar shape, the position and shape of the bank BN may be appropriately selected.

The thin film transistor T may be implemented in various structures such as a bottom gate, a top gate, and a double gate structure. That is, the thin film transistor T may include a semiconductor layer, a gate electrode, and a source/drain electrode, and the semiconductor layer, the gate electrode, and the source/drain electrode may be disposed on different layers with at least one insulating layer interposed therebetween. can

At least one insulating layer IN may be interposed between the thin film transistor T and the organic light emitting diode OLE. The insulating layer IN may include a planarization layer made of an organic material such as photo acryl, polyimide, benzocyclobutene resin, or acrylate. The planarization layer may planarize the surface of the substrate SUB on which the thin film transistor T and various signal lines are formed. Although not shown, the insulating film may further include a protective film made of a silicon oxide film (SiOx), a silicon nitride film (SiNx), or a multilayer thereof, and the protective film may be interposed between the planarization film and the thin film transistor T. The thin film transistor T and the organic light emitting diode OLE may be electrically connected through a pixel contact hole PH passing through one or more insulating layers IN.

The organic light emitting diode OLE includes a first electrode E1 , a second electrode E2 facing each other, and an organic compound layer OL interposed between the first electrode E1 and the second electrode E2 . . The first electrode E1 may be an anode, and the second electrode may be a cathode.

The first electrode E1 may be formed of a single layer or multiple layers. The first electrode E1 may further include a reflective layer to function as a reflective electrode. The reflective layer may be made of Al, Cu, Ag, Ni, or an alloy thereof, preferably APC (silver/palladium/copper alloy). For example, the first electrode E1 may be formed of a triple layer made of ITO/Ag/ITO. In this case, the lower ITO may be formed for the purpose of improving adhesion properties between the organic film (planarization film) and Ag. The first electrode E1 may be divided to correspond to each pixel, and may be allocated to each pixel.

A bank BN partitioning neighboring pixels is positioned on the substrate SUB on which the first electrode E1 is formed. The bank BN may be formed of an organic material such as polyimide, benzocyclobutene resin, or acrylate. The bank BN includes an opening for exposing most of the central portion of the first electrode E1 . A portion of the first electrode E1 exposed by the bank BN may be defined as a light emitting area. The bank BN may be disposed to expose a central portion of the first electrode E1 and cover a side end of the first electrode E1 .

The bank BN includes a recess BH. The concave portion BH may have a hole shape that completely penetrates the entire thickness of the bank BN to expose the lower layer, and may have a groove shape provided by being partially recessed inward from the upper surface of the bank BN. . The concave portion BH is disposed between neighboring pixels in one area.

The organic light emitting diode display according to the first exemplary embodiment includes an anti-reflection layer RP disposed on a first electrode E1 . The antireflection layer RP is a layer provided to dissipate waveguided light from neighboring pixels, and functions to minimize reflectance of waveguided light by inducing destructive interference of light.

Referring further to FIG. 9 , the anti-reflection layer RP has a structure in which a reflective metal layer RFL, an intermediate layer IL, and a transflective metal layer TFL are sequentially stacked. More specifically, the wave-guided light is incident on the anti-reflection layer (RP). A portion RL1 of the light incident to the antireflection layer RP is reflected by the transflective metal layer TFL, another portion is absorbed, and another portion is transmitted. Part of the transmitted light RL2 passes through the intermediate layer IL and is reflected back by the reflective metal layer RFL. In this case, the light RL1 reflected by the transflective metal layer TFL and the light RL2 reflected by the reflective metal layer RFL are annihilated by destructive interference. That is, when the phase difference between the light RL1 reflected by the transflective metal layer TFL and the light RL2 reflected by the reflective metal layer RFL becomes λ/2, destructive interference may occur and disappear. In order to induce destructive interference of the lights RL1 and RL2, the thickness of the intermediate layer IL may be appropriately selected. In other words, the intermediate layer IL may be defined as a layer for forming a light path difference between the light RL1 reflected by the transflective metal layer TFL and the light RL2 reflected by the reflective metal layer RFL. there is.

The transflective metal layer TFL may be formed of Mo, Ti, Zr, Hf, V, Nb, Ta, Cr, W, Cu, Ni, Mg, Ca, Al, Ag, or at least one alloy including the same. Preferably, the transflective metal layer (TFL) may be MoTi.

The intermediate layer IL may be formed of a transparent insulating material or a transparent conductive material. For example, the intermediate layer IL may be formed of an inorganic material such as a silicon oxide film (SiOx) or a silicon nitride film (SiNx), and may include Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Zinc Oxide (ZnO) and ITZO ( It may be made of a conductive oxide such as Indium Tin Zinc Oxide).

The reflective metal layer RFL may be formed of Mo, Ti, Zr, Hf, V, Nb, Ta, Cr, W, Cu, Ni Mg, Ca, Al, Ag, or at least one alloy including the same. The reflective metal layer RFL reflects light transmitted through the transflective metal layer TFL and the intermediate layer IL among waveguided light. The reflective metal layer RFL may be formed of the same material as the transflective metal layer TFL. In this case, in consideration of various functions, the thicknesses of the reflective metal layer RFL and the transflective metal layer TFL may be differently controlled. For example, both the reflective metal layer (RFL) and the transflective metal layer (TFL) may be MoTi, and the transflective metal layer (TFL) is a reflective metal layer ( RFL) may be set to a thinner thickness.

An organic compound layer OL is formed on the substrate SUB on which the bank BN is formed. The organic compound layer OL is extended and disposed on the thin film transistor substrate SUB to cover the pixels. The organic compound layer OL may have a multi-stack structure such as a two-stack structure. In the two-stack structure, a charge generation layer (CGL) disposed between the first electrode E1 and the second electrode E2, and a charge generation layer disposed below and above the charge generation layer with the charge generation layer therebetween, respectively It may include a first stack and a second stack. Each of the first stack and the second stack includes an emission layer, and a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. ) and may further include at least one of common layers. The light emitting layer of the first stack and the light emitting layer of the second stack may include light emitting materials of different colors.

A second electrode E2 is formed on the substrate SUB on which the organic compound layer OL is formed. The second electrode E2 is made of a transparent conductive material such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), or Zinc Oxide (ZnO), or an opaque conductive material such as Mg, Ca, Al, or Ag is thinly formed. and can function as a transmissive electrode. The second electrode E2 may be integrally extended and disposed on the thin film transistor substrate SUB to cover the pixels.

The organic light emitting display device according to the present invention includes a color filter (CF). One color filter CF may be allocated to each pixel. The color filter CF may include a red (R), green (G), and blue (B) color filter CF that transmits red (R), green (G), and blue (B) light. Each of the red (R), green (G) and blue (B) color filters CF is assigned to a corresponding red (R), green (G) and blue (B) pixel.

For example, the color filter CF may be formed on the thin film transistor substrate SUB. An encapsulation layer (ENC) is formed between the color filter and the organic light emitting diode (OLE) to prevent deterioration of the organic light emitting diode (OLE) by exposure to the environment provided during the color filter (CF) forming process. ) may be interposed. In addition, the encapsulation layer ENC may prevent moisture and/or oxygen from flowing into the organic light emitting diode OLE. Accordingly, there is an advantage in that it is possible to prevent a decrease in lifetime and a decrease in luminance of the organic light emitting diode (OLE). The encapsulation layer ENC may be provided in a form in which at least one inorganic layer and at least one organic layer are stacked. In this case, the inorganic layer and the organic layer may be alternately disposed. The neighboring color filters CF may be partitioned by the black matrix BM formed on the encapsulation layer ENC. (FIG. 8 (a))

As another example, the color filter CF may be formed on the opposite substrate CSUB opposite to the thin film transistor substrate SUB. The counter substrate CSUB may be made of a transparent material so that light emitted from the organic light emitting diode OLE can pass therethrough. The adjacent color filters CF may be partitioned by the black matrix BM formed on the opposing substrate CSUB. The stacking order of the color filter CF and the black matrix BM may be changed. (FIG. 8 (b))

10 is a simulation result for explaining the effect of the anti-reflection layer. 10 is a simulation result of measuring reflectance for each wavelength when the reflective metal layer (RFL), the intermediate layer (IL), and the transflective metal layer (TFL) constituting the anti-reflection layer (RP) are MoTi, ITO, and MoTi, respectively.

Referring to FIG. 10 , in the case of the antireflection layer (RP) in which MoTi, ITO, and MoTi are sequentially stacked, it can be seen that the reflectivity is about 23% to 3% in a wavelength range of 380 nm to 780 nm. This means that by providing the anti-reflection layer RP, it is possible to control the reflectance of light incident from the corresponding region to be low. In other words, the provision of the anti-reflection layer (RP) means that reflection of wave-guided light can be minimized and color mixing defects can be effectively reduced.

In fact, in the case of the first electrode E1 (FIG. 8) made of the ITO/APC/ITO triple layer, since it has a reflectivity of 90% or more, it is difficult to control the waveguided light. In the first embodiment of the present invention, by providing an anti-reflection layer (RP) having a low reflection characteristic on the edge of the first electrode (E1, FIG. 8), the waveguided incident light from the neighboring pixel is equivalent through destructive interference. It can be partially lost, and thus color mixing defects can be minimized. Accordingly, the first embodiment of the present invention has an advantage in that it is possible to provide an organic light emitting display device having significantly improved display characteristics such as color gamut.

<Second embodiment>

11 is a view for explaining an arrangement example of an anti-reflection layer according to a second embodiment of the present invention. In the description of the second embodiment, a description of a configuration substantially the same as that of the first embodiment will be omitted.

Referring to FIG. 11 , the organic light emitting diode display according to the second exemplary embodiment includes pixels PXL having organic light emitting diodes and a bank BN partitioning neighboring pixels PXL. The organic light emitting diode OLE includes a first electrode E1 , a second electrode, and an organic compound layer interposed between the first electrode E1 and the second electrode. An anti-reflection layer RP is positioned on the first electrode E1 .

The anti-reflection layer RP according to the second embodiment of the present invention is disposed to surround the upper surface and the side surface of the first electrode E1 . When the anti-reflection layer RP is disposed only on the upper surface of the first electrode E1 , the edge of the first electrode E1 may be exposed as it is without being blocked by the anti-reflection layer RP when the alignment is poor. In this case, the wave-guided light may be incident on the edge of the exposed first electrode E1 , which may cause color mixing defects. To prevent this, the anti-reflection layer RP according to the second embodiment of the present invention may extend longer in the inside direction of the bank BN compared to the first embodiment in consideration of the alignment defect, and the first electrode E1 It may be arranged to surround at least a portion and side of the upper surface of the.

However, in this case, since the anti-reflection layer RP has conductivity, it is necessary to limit contact between the anti-reflection layers RP respectively in contact with the adjacent first electrodes E1 . Accordingly, the adjacent antireflection layers RP extend in the inner direction of the bank BN and are disposed to be spaced apart from each other by a predetermined distance DD inside the bank BN. The predetermined interval DD may be set in consideration of mutual signal interference.

<Third embodiment>

12 is a view for explaining an arrangement example of an anti-reflection layer according to a third embodiment of the present invention. In the description of the third embodiment, a description of the components substantially the same as those of the first embodiment will be omitted.

Referring to FIG. 12 , the organic light emitting diode display according to the third exemplary embodiment includes pixels PXL having organic light emitting diodes and a bank BN partitioning neighboring pixels PXL. The organic light emitting diode OLE includes a first electrode E1 , a second electrode, and an organic compound layer interposed between the first electrode E1 and the second electrode. An anti-reflection layer RP is positioned on the first electrode E1 .

For example, as shown in FIG. 12B , the anti-reflection layer RP is disposed on the edge of the first electrode E1 , but is not completely covered by the bank BN, but only partially covered. That is, the opening of the bank BN may expose at least a portion of the anti-reflection layer RP. In this case, it has the advantage of effectively blocking the wave-guided light along the surface of the bank BN.

As another example, as shown in FIG. 12C , the anti-reflection layer RP may be disposed on the edge of the first electrode E1 , and may be disposed to be completely covered by the bank BN. In order to prevent light loss and deterioration of optical properties due to the antireflection layer RP in the light emitting area EA, it may be preferable that the antireflection layer RP be completely covered by the bank BN.

<Fourth embodiment>

13 is a view for explaining an arrangement example of an anti-reflection layer according to a fourth embodiment of the present invention. In describing the fourth embodiment, a description of the components substantially the same as those of the first embodiment will be omitted.

Referring to FIG. 13 , the organic light emitting diode display according to the fourth exemplary embodiment includes pixels PXL having organic light emitting diodes and a bank BN partitioning neighboring pixels PXL. The organic light emitting diode OLE includes a first electrode E1 , a second electrode, and an organic compound layer interposed between the first electrode E1 and the second electrode. An anti-reflection layer RP is positioned on the first electrode E1 .

13A , the anti-reflection layer RP may be disposed along the shape of the first electrode E1 at an edge thereof.

Alternatively, as shown in (b) of FIG. 13 , the anti-reflection layer RP may be selectively provided according to a location. That is, the anti-reflection layer RP may be selectively provided at a necessary position without needing to be disposed on every edge of the first electrode E1 arranged in the pixels PXL.

When the neighboring pixels PXL are allocated as pixels PXL emitting the same color, color mixing between the neighboring pixels PXL may not be a problem. In consideration of this, in the fourth embodiment of the present invention, the arrangement position of the anti-reflection layer RP may be determined based on the color allocated to the neighboring pixels PXL.

For example, based on the first pixel PXL1 emitting a first color, a pixel PXL adjacent to the first pixel PXL in the first direction is a second pixel PXL2 emitting a second color , and a pixel PXL adjacent to the first pixel PXL1 in the second direction may be allocated as a third pixel PXL3 emitting a first color. Here, since the first pixel PXL1 and the second pixel PXL2 emit different colors, among the edges of the first electrode E1 in the first pixel PXL1 , the second pixel PXL2 is adjacent to each other. The anti-reflection layer RP may be selectively formed at an edge and an edge adjacent to the first pixel PXL1 among edges of the first electrode E1 in the second pixel PXL2 . In addition, since the first pixel PXL1 and the third pixel PXL3 emit the same color, among the edges of the first electrode E1 in the first pixel PXL1 , the edge adjacent to the third pixel PXL3 is The anti-reflection layer RP may not be formed at an edge adjacent to the first pixel PXL1 among the positions and edges of the first electrode E1 in the third pixel PXL1 .

As described above, in the fourth embodiment of the present invention, since it is sufficient to selectively form the antireflection layer RP only in a necessary region, it has the advantage of securing the degree of freedom in the process. In addition, in the region where the anti-reflection layer RP is not formed, the width of the bank BN is formed to be relatively narrow, so that an opening ratio corresponding to the width can be secured.

Those skilled in the art through the above description will be able to make various changes and modifications without departing from the technical spirit of the present invention. Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

PXL : Pixel SUB : Thin Film Transistor Substrate
OLE: organic light emitting diode E1: first electrode
OL: organic compound layer E2: second electrode
BN: Bank BH: Concave
RP: anti-reflection layer RFL: reflective metal layer
IL: Intermediate layer TFL: Translucent metal layer

Claims (17)

An organic light emitting diode display including pixels having organic light emitting diodes, the organic light emitting diode display comprising:
a first electrode of the organic light emitting diode;
an anti-reflection layer disposed on an edge of the first electrode; and
a bank covering at least a portion of the antireflection layer and having an opening exposing at least a portion of the first electrode;
The pixels are
a first pixel emitting a first color;
a second pixel adjacent to the first pixel in a first direction and emitting a second color; and
and a third pixel adjacent to the first pixel in a second direction and emitting the first color,
The anti-reflection layer,
an edge adjacent to the second pixel among edges of the first electrode in the first pixel and an edge adjacent to the first pixel among edges of the first electrode in the second pixel;
an edge adjacent to the third pixel among edges of the first electrode in the first pixel and an edge adjacent to the first pixel among edges of the first electrode in the third pixel display device.
The method of claim 1,
The anti-reflection layer,
and a reflective metal layer, an intermediate layer, and a transflective metal layer sequentially stacked on the first electrode.
3. The method of claim 2,
The anti-reflection layer,
Destructive interference of the first reflected light reflected by the semi-transmissive metal layer among the light incident on the anti-reflection layer and the second reflected light reflected by the reflective metal layer among the light transmitted through the semi-transmissive metal layer and the intermediate layer induces destructive interference, organic light emitting display device.
4. The method of claim 3,
and a phase difference between the first reflected light and the second reflected light is set to λ/2.
3. The method of claim 2,
The reflective metal layer,
Mo, Ti, Zr, Hf, V, Nb, Ta, Cr, W, Cu, Ni Mg, Ca, Al, Ag and one or more alloys comprising the same, the organic light emitting display device.
3. The method of claim 2,
The intermediate layer is
An organic light emitting display device selected from any one of a silicon oxide film (SiOx), a silicon nitride film (SiNx), indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and indium tin zinc oxide (ITZO).
3. The method of claim 2,
The transflective metal layer,
Mo, Ti, Zr, Hf, V, Nb, Ta, Cr, W, Cu, Ni Mg, Ca, Al, Ag and one or more alloys comprising the same, the organic light emitting display device.
3. The method of claim 2,
The transflective metal layer and the reflective metal layer,
containing the same substance;
The transflective metal layer,
An organic light emitting diode display having a thickness smaller than that of the reflective metal layer.
The method of claim 1,
The anti-reflection layer,
at an edge of the first electrode, covering an upper surface and a side surface of the first electrode.
The method of claim 1,
Anti-reflection layers disposed on each of the neighboring pixels,
The organic light emitting diode display device, which is disposed to be spaced apart from each other by a predetermined interval in the bank.
The method of claim 1,
The opening of the bank is
and exposing at least a portion of the anti-reflection layer.
The method of claim 1,
The bank is
An organic light emitting display device that completely covers the anti-reflection layer.
delete delete The method of claim 1,
The bank is
at least one concave portion provided between the neighboring pixels,
The concave portion,
An organic light emitting diode display having a hole shape completely penetrating the entire thickness of the bank or a groove shape partially recessed inward from an upper surface of the bank.
The method of claim 1,
an encapsulation layer covering the pixels; and
The organic light emitting display device further comprising a color filter disposed on the encapsulation layer.
The method of claim 1,
a thin film transistor substrate on which the organic light emitting diodes are arranged; and
Comprising a counter substrate facing the thin film transistor,
The counter substrate is
An organic light emitting display device comprising a color filter.

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