阅读说明：本技术 有机发光显示装置及其制造方法 (Organic light emitting display device and method of manufacturing the same ) 是由 尹準浩 李相彬 赵玧朱 于 2019-12-20 设计创作，主要内容包括：根据本发明的有机发光显示装置包括：基板；多个第一堤层,所述多个第一堤层沿第一方向和不同于所述第一方向的第二方向设置在所述基板上,以限定出多个像素；多个第二堤层,所述多个第二堤层沿所述第一方向设置在所述第一堤层上,以将不同颜色的像素列分隔开；和第三堤层,所述第三堤层沿所述第二方向形成在每个像素列中,以将每个像素列划分为多个组,每个组都包括多个像素。(An organic light emitting display device according to the present invention includes: a substrate; a plurality of first bank layers disposed on the substrate in a first direction and a second direction different from the first direction to define a plurality of pixels; a plurality of second bank layers disposed on the first bank layer in the first direction to separate pixel columns of different colors; and a third bank layer formed in each pixel column along the second direction to divide each pixel column into a plurality of groups, each group including a plurality of pixels.)

1. An organic light emitting display device comprising:

a substrate;

a plurality of first bank layers disposed on the substrate in a first direction and a second direction different from the first direction to define a plurality of pixels;

a plurality of second bank layers disposed on the first bank layer in the first direction to separate pixel columns of different colors; and

a third bank layer formed in each pixel column along the second direction to divide each pixel column into a plurality of groups, each group including a plurality of pixels.

2. The organic light emitting display device of claim 1, further comprising:

a thin film transistor formed on the substrate; and

a light emitting element formed on the substrate.

3. The organic light-emitting display device according to claim 2, wherein the light-emitting element comprises:

a first electrode and a second electrode; and

an organic light emitting layer disposed between the first electrode and the second electrode.

4. An organic light-emitting display device according to claim 3, wherein the organic light-emitting layer is continuously formed between the plurality of pixels within a group and is disconnected between the plurality of groups.

5. The organic light emitting display device according to claim 1, wherein the plurality of groups formed in each pixel column include the same number of pixels.

6. The organic light emitting display device according to claim 1, wherein the plurality of groups formed in each pixel column include a different number of pixels.

7. The organic light-emitting display device according to claim 6, wherein the number of pixels included in the group increases from a periphery of each pixel column toward a central portion of each pixel column.

8. The organic light emitting display device of claim 1, wherein the groups corresponding to the pixel columns of different colors include different numbers of pixels.

9. The organic light emitting display device according to claim 1, wherein the third bank layer of one pixel column is arranged to be misaligned with the third bank layer of another pixel column adjacent in the second direction.

10. The organic light emitting display device of claim 1, wherein the first bank layer is made of a hydrophilic material, the second bank layer is made of a hydrophobic material, and the third bank layer is made of a hydrophobic material.

11. The organic light emitting display device of claim 1, wherein the first bank layer is made of a hydrophilic material, the second bank layer is made of a hydrophobic material, and the third bank layer is made of a hydrophilic material.

12. The organic light emitting display device of claim 1, wherein a height of the third bank layer is greater than a height of the first bank layer.

13. The organic light emitting display device of claim 12, wherein a height of the third bank layer is less than a height of the second bank layer.

14. The organic light emitting display device of claim 12, wherein a width of the third bank layer is less than a width of the second bank layer.

15. The organic light emitting display device according to claim 1, wherein the third bank layer is formed on the first bank layer in the second direction, and the second bank layer and the third bank layer are formed to have a smaller width than the first bank layer.

16. The organic light emitting display device according to claim 1, further comprising a dummy area disposed on an outermost portion of the pixel column and including a plurality of dummy pixels.

17. An organic light-emitting display device according to claim 16 wherein the dummy regions are separated from the outermost component by the third bank layer.

18. An organic light-emitting display device according to claim 16 wherein the dummy regions are separated from the outermost component by the first bank layer.

19. The organic light-emitting display device according to claim 17 or 18, wherein no light-emitting element is formed in the dummy region and an organic light-emitting layer is formed.

20. The organic light emitting display device according to claim 16, wherein a sum of the number of dummy pixels in a dummy area adjacent to an outermost group and the number of pixels in the outermost group is equal to the number of pixels of another group.

21. The organic light-emitting display device according to claim 20, wherein a light-emitting element is provided in the dummy region.

22. A method of manufacturing an organic light emitting display device, the method comprising:

forming a plurality of first bank layers disposed on a substrate in a first direction and a second direction different from the first direction to define a plurality of pixels, a plurality of second bank layers disposed on the first bank layers in the first direction to separate pixel columns of different colors, and a third bank layer configured to divide each pixel column into a plurality of groups in the second direction;

forming a first electrode in the pixel;

dispensing an organic light emitting material in each of the plurality of groups in each pixel column and dispersing the organic light emitting material over an entire area of each of the plurality of groups; and

drying the organic light emitting material to form an organic light emitting layer.

23. The method of claim 22, wherein the first bank layer is made of a hydrophilic material, the second bank layer is made of a hydrophobic material, and the third bank layer is made of a hydrophobic material.

24. The method of claim 22, wherein the first bank layer is made of a hydrophilic material, the second bank layer is made of a hydrophobic material, and the third bank layer is made of a hydrophilic material.

Technical Field

The present invention relates to an organic light emitting display device and a method of manufacturing the same, and more particularly, to an organic light emitting display device including an organic light emitting layer having a uniform thickness and a method of manufacturing the same.

Background

Recently, various flat panel display devices configured in a thin shape to greatly reduce weight and volume have been developed. Among these flat panel display devices, the organic light emitting display device is a self-light emitting device in which an organic light emitting layer emits light, and the organic light emitting display device has advantages of a fast response speed, a high light emitting efficiency, a high luminance, and a wide viewing angle.

The organic light emitting layer is made of an organic light emitting material and is mainly formed by a thermal deposition process, and when the organic light emitting layer is formed by the thermal deposition process, the following problems occur.

In order to thermally deposit an organic light emitting material, a metal mask is disposed on the entire surface of a substrate, and the organic light emitting material is evaporated and deposited on the substrate in a state where other regions except a display region are blocked to form an organic light emitting layer. Therefore, in order to form the organic light emitting layer, processes such as setting and aligning a metal mask, depositing an organic light emitting material, and removing the metal mask are required, which causes the manufacturing process to be complicated, the manufacturing process to be delayed, and the manufacturing cost to be increased.

In addition, when the metal mask is misaligned, defects occur in the organic light emitting layer, and thus a separate alignment device for precisely aligning the metal mask is required. Further, in recent years, as display devices become larger, thermal deposition apparatuses also become larger, and such an increase in thermal deposition apparatuses not only increases the manufacturing cost, but also makes thermal deposition practically impossible in the case where display devices are made into an oversized size above a certain size.

Disclosure of Invention

An object of the present invention is to provide an organic light emitting display device and a method of manufacturing the same, which can prevent an organic light emitting layer having a non-uniform thickness from being formed due to variation in the amount of one droplet and aggregation of an organic light emitting material in a solution state by dividing a pixel column into a plurality of groups each including a plurality of pixels, distributing the organic light emitting material into each group, and then dispersing the organic light emitting material in each group.

In order to achieve the object, an organic light emitting display device according to the present invention includes: a substrate; a plurality of first bank layers disposed on the substrate in a first direction and a second direction different from the first direction to define a plurality of pixels; a plurality of second bank layers disposed on the first bank layer in the first direction to separate pixel columns of different colors; and a third bank layer formed in each pixel column along the second direction to divide each pixel column into a plurality of groups, each group including a plurality of pixels.

The organic light emitting display device may further include: a thin film transistor formed on the substrate; and a light emitting element formed on the substrate.

The light emitting element on the substrate may include: a first electrode and a second electrode; and an organic light emitting layer disposed between the first electrode and the second electrode. The organic light emitting layer is continuously formed between the plurality of pixels within a group and is disconnected between the plurality of groups.

The plurality of groups formed in each pixel column may include the same number of pixels, or the plurality of groups formed in each pixel column may include different numbers of pixels. The number of pixels included in the group may increase from the periphery of each pixel column toward the central portion of each pixel column, and groups corresponding to pixel columns of different colors may include different numbers of pixels. The third bank layer of one pixel column may be arranged to be misaligned with the third bank layer of another pixel column adjacent in the second direction.

The first bank layer may be made of a hydrophilic material, the second bank layer may be made of a hydrophobic material, and the third bank layer may be made of a hydrophobic material. Further, the first bank layer may be made of a hydrophilic material, the second bank layer may be made of a hydrophobic material, and the third bank layer may be made of a hydrophilic material.

The third bank layer may have a height greater than that of the first bank layer. The third bank layer may have a height less than a height of the second bank layer. A width of the third bank layer may be smaller than a width of the second bank layer. The third bank layer may be formed on the first bank layer in the second direction, and the second bank layer and the third bank layer may be formed to have a smaller width than the first bank layer.

The organic light emitting display device may further include a dummy region disposed on an outermost portion of the pixel column and including a plurality of dummy pixels. The dummy region may be separated from the outermost component by the third bank layer. The dummy region may be separated from the outermost component by the first bank layer. The dummy region may have an organic light emitting layer formed thereon, without forming a light emitting element.

The sum of the number of dummy pixels in the dummy area adjacent to the outermost group and the number of pixels in the outermost group may be equal to the number of pixels of the other group. A light emitting element may be disposed in the dummy area.

The method of manufacturing an organic light emitting display device includes: forming a plurality of first bank layers disposed on a substrate in a first direction and a second direction different from the first direction to define a plurality of pixels, a plurality of second bank layers disposed on the first bank layers in the first direction to separate pixel columns of different colors, and a third bank layer configured to divide each pixel column into a plurality of groups in the second direction; forming a first electrode in the pixel; dispensing an organic light emitting material in each of the plurality of groups in each pixel column and dispersing the organic light emitting material over an entire area of each of the plurality of groups; and drying the organic light emitting material to form an organic light emitting layer.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principles of the embodiments of the invention.

Fig. 1 is a schematic circuit diagram of one pixel of an organic light emitting display device according to the present invention.

Fig. 2 is a plan view schematically illustrating the structure of an organic light emitting display device according to a first embodiment of the present invention.

Fig. 3A and 3B are cross-sectional views taken along line I-I 'and line II-II' of fig. 2, respectively.

Fig. 4 is a flowchart illustrating a method of manufacturing an organic light emitting display device according to the present invention.

Fig. 5 is a view illustrating a method of coating an organic light emitting material in an organic light emitting display device according to the present invention.

Fig. 6 is a graph illustrating an average variation amount of the organic light emitting material coated on one pixel with respect to the number of pixels included in one group.

Fig. 7A and 7B are graphs illustrating thicknesses of organic light emitting layers measured at two specific points in one pixel column in an organic light emitting display device in which pixel columns are not grouped and in an organic light emitting display device according to the first embodiment of the present invention in which pixel columns are grouped, respectively.

Fig. 8 is a plan view of an organic light emitting display device according to a second embodiment of the present invention.

Fig. 9A and 9B are a plan view and a cross-sectional view of an organic light emitting display device according to a third embodiment of the present invention, respectively.

Fig. 10A and 10B are a plan view and a cross-sectional view, respectively, of an organic light emitting display device according to a fourth embodiment of the present invention.

Fig. 11 is a plan view illustrating a structure of an organic light emitting display device according to a fifth embodiment of the present invention.

Fig. 12 is a plan view illustrating a structure of an organic light emitting display device according to a sixth embodiment of the present invention.

Detailed Description

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

In order to form an organic light emitting layer of an organic light emitting display device, a coating method is used in the present invention instead of a thermal deposition method. That is, the organic light emitting layer may be formed by dispensing an organic light emitting material on a set area on the substrate and then dispersing the dispensed organic light emitting material on the substrate. Therefore, the coating method can simplify the manufacturing process, can be rapidly performed, and can also be advantageously applied to a display device having a large area, as compared to forming an organic light emitting layer by a thermal deposition process.

In the present invention, the organic light emitting layer is formed by arranging pixels of the same color in a stripe manner in a length direction, dividing each pixel column of the same color into a plurality of groups, and dispensing an organic light emitting material in one region of each of the divided groups such that the organic light emitting material is coated on the entire region of the corresponding group. Accordingly, since the organic light emitting layer is formed by dispensing the organic light emitting material in a solution state in each of the plurality of groups, the thickness unevenness of the organic light emitting layer due to the variation of one droplet amount can be solved. Further, since the organic light emitting material is dispersed in the divided regions, not in the entire pixel columns, the thickness unevenness of the organic light emitting layer can be solved by reducing the stress of the organic light emitting material coated in each group.

Fig. 1 is a schematic circuit diagram of one pixel of an organic light emitting display device according to the present invention.

As shown in fig. 1, the organic light emitting display device according to the present invention includes a gate line G L, a data line D L, and a power line P L that cross each other to define a pixel P in which a switching thin film transistor Ts, a driving thin film transistor Td, a storage capacitor Cst, and an organic light emitting element D are disposed.

The switching thin film transistor Ts is connected to the gate line G L and the data line D L, the driving thin film transistor Td and the storage capacitor Cst are connected between the switching thin film transistor Ts and the power line P L, and the organic light emitting element D is connected to the driving thin film transistor Td.

In the organic light emitting display device having such a structure, when the switching thin film transistor Ts is turned on in response to a gate signal applied through the gate line G L, a data signal applied through the data line D L is applied through the switching thin film transistor Ts to the gate electrode of the driving thin film transistor Td and one electrode of the storage capacitor Cst.

The driving thin film transistor Td is turned on in response to a data signal applied to a gate electrode thereof, and as a result, a current proportional to the data signal flows from the power line P L to the organic light emitting element D through the driving thin film transistor Td, and the organic light emitting element D emits light having a luminance proportional to the current flowing through the driving thin film transistor Td.

Here, the storage capacitor Cst is charged with a voltage proportional to the data signal, so that the voltage of the gate electrode of the driving thin film transistor Td is kept constant for one frame.

Fig. 2 is a plan view schematically illustrating the structure of an organic light emitting display device 100 according to a first embodiment of the present invention.

As shown in fig. 2, a plurality of red (R) pixels, a plurality of green (G) pixels, and a plurality of blue (B) pixels are arranged in the organic light emitting display device 100 according to the first embodiment of the present invention, and an R organic light emitting layer, a G organic light emitting layer, and a B organic light emitting layer are formed in the R pixels, the G pixels, and the B pixels, respectively. Here, the R pixels, the G pixels, and the B pixels are arranged in a stripe manner, and a plurality of the R pixels, a plurality of the G pixels, and a plurality of the B pixels are each arranged in a longitudinal direction. Specifically, R pixels, G pixels, or B pixels of the same color are arranged in a longitudinal direction of the organic light emitting display device 100, and R pixels, G pixels, and B pixels of different colors are alternately arranged in a lateral direction of the organic light emitting display device 100, for example, in the order of R-G-B-R-G-B. However, the R pixels, the G pixels, and the B pixels may not be arranged in this order, but may be arranged in a different order.

The first bank layer 142 is formed at the periphery of each of the R, G, and B pixels such that each of all the R, G, and B pixels is separated from the other pixels. That is, the first bank layer 142 defines one pixel in which one organic light emitting element of the organic light emitting display device is disposed.

The second bank layer 144 is disposed in a boundary between the R, G, and B pixel columns arranged in the longitudinal direction, and is disposed in an outermost region of the organic light emitting display device 100. Since the pixels of the same color are arranged in a stripe shape in the longitudinal direction to form one pixel column, the second bank layer 144 is disposed in a boundary between pixel columns of different colors, thereby separating the pixel columns of different colors.

Although the first bank layer 142 is formed in a boundary between pixels of the same color arranged along a pixel column to separate adjacent pixels of the same color, organic light emitting layers of the respective colors are formed over all the pixels arranged within the respective pixel column across the first bank layer 142. The second bank layer 144 is formed in a boundary between the pixels of different colors to prevent organic light emitting materials of different colors from being mixed into the organic light emitting layers formed in the respective pixels.

Each of the plurality of pixel columns is divided into a plurality of groups GR1, GR2,. and GRn, and a third bank layer 146 is formed in a boundary between these groups GR1, GR2,. and GRn. That is, n-1 (where n is a natural number greater than 1) third bank layers 146 are formed in one pixel column to divide one pixel column into n groups.

The third bank layer 146 separates organic light emitting layers formed in each of the plurality of groups GR1, GR2,. and GRn adjacent to each other. That is, organic light emitting layers having the same color are formed in the entire pixel columns, and in a plurality of pixels arranged in each of these groups GR1, GR2,. and GRn, the organic light emitting layers are continuously formed across the first bank layer 142, but between adjacent groups GR1, GR2,. and GRn, the organic light emitting layers are formed to be disconnected from each other.

As described above, in the present invention, an organic light emitting layer is formed in each of the groups GR1, GR2,. and GRn to be disconnected (or discontinuous) from the organic light emitting layers of the other adjacent groups GR1, GR2,. and GRn by disposing a plurality of third bank layers 146 in each pixel column, dividing each pixel column into a plurality of groups GR1, GR2,. and GRn, and allocating an organic light emitting material in each of the groups GR1, GR2,. and GRn, and then dispersing the allocated organic light emitting material in each of the groups GR1, GR2,. and GRn. That is, by dispensing an organic light emitting material in a solution state for each of the groups GR1, GR2,. and GRn to form an organic light emitting layer in a corresponding one of the groups GR1, GR2,. and GRn, an organic light emitting layer having a uniform thickness can be formed over the entire pixel column, which will be described in detail below.

Fig. 3A and 3B are cross-sectional views taken along line I-I 'and line II-II' of fig. 2, respectively, and referring to the two views, an organic light emitting display device 100 according to an embodiment of the present invention will be described in more detail. Here, only the structure of R pixels adjacent to each other in the longitudinal direction (i.e., the pixel column direction) and the structure of R pixels and G pixels adjacent to each other in the lateral direction are shown in the drawings. However, since all of the R, G and B pixels of the present embodiment are formed in the same structures as those described above, the structure of the entire organic light emitting display device 100 is described by describing those structures described above.

As shown in fig. 3A and 3B, a buffer layer 112 is formed on the entire first substrate 110 on which the first and second groups GR1 and GR2 are formed, each of the first and second groups GR1 and GR2 is arranged in the pixel column direction and includes a plurality of pixels p (r), and a driving thin film transistor Td is provided in each pixel on the buffer layer 112.

The first substrate 110 may be made of a transparent material such as glass, or may be made of a transparent flexible plastic such as polyimide. In addition, the buffer layer 112 may be formed as a single layer or a plurality of layers made of an inorganic material such as SiOx or SiNx.

A driving thin film transistor Td is formed in each of the plurality of pixels p (r). The driving thin film transistor Td includes a semiconductor layer 122 formed in the pixel on the buffer layer 112, a gate insulating layer 123 formed in a partial region of the semiconductor layer 122, a gate electrode 125 formed on the gate insulating layer 123, an interlayer insulating layer 114 formed over the entire first substrate 110 to cover the gate electrode 125, and a source electrode 127 and a drain electrode 128 in contact with the semiconductor layer 122 through first and second contact holes 114a and 114b formed in the interlayer insulating layer 114.

In addition, although not shown in the drawings, a switching thin film transistor may be disposed on the first substrate 110, and the switching thin film transistor may have the same structure as the driving thin film transistor Td.

The semiconductor layer 122 may be formed of crystalline silicon or an oxide semiconductor such as Indium Gallium Zinc Oxide (IGZO), and the semiconductor layer 122 includes a channel layer at a central region thereof and doped layers on both side surfaces thereof such that the source and drain electrodes 127 and 128 are in contact with the doped layers.

The gate electrode 125 may be made of metal such as Cr, Mo, Ta, Cu, Ti, Al, or Al alloy, and the gate insulating layer 123 and the interlayer insulating layer 114 may be formed as a single layer made of inorganic material such as SiOx or SiNx or an inorganic layer having a two-layer structure of SiOx and SiNx. The gate insulating layer 123 is illustrated in the drawings as being disposed only under the gate electrode 125, but the gate insulating layer 123 may be formed over the entire first substrate 110.

The source electrode 127 and the drain electrode 128 may be made of Cr, Mo, Ta, Cu, Ti, Al, or Al alloy, but the present invention is not limited thereto.

Further, in the drawings and the above description, the driving thin film transistor Td is described as being formed in a specific structure, but the driving thin film transistor Td of the present invention is not limited to the illustrated structure, and any structure of the driving thin film transistor may be applied.

A protective layer 116 is formed over the first substrate 110 on which the driving thin film transistor Td is formed. The protective layer 116 may be made of an organic material such as optical acryl, but may also be formed as a multilayer of an inorganic layer and an organic layer. A contact hole 116a is formed in the protective layer 116.

A first electrode 130 is formed on the protective layer 116 and the first electrode 130 is electrically connected to the drain electrode 128 of the driving thin film transistor Td through the contact hole 116 a. Further, the first electrode 130 is formed in a single layer or a plurality of layers made of a metal such as Ca, Ba, Mg, Al, or Ag or an alloy thereof, and the first electrode 130 is connected to the drain electrode 128 of the driving thin film transistor Td, thereby allowing an image signal from the outside to be applied to the first electrode 130.

A first bank layer 142 is formed on the protective layer 116 at the boundary between all pixels p (R) and pixels p (G), and a second bank layer 144 is formed on the first bank layer 142 in the boundary between the pixels of different colors, i.e., between the R pixel p (R) and the G pixel p (G). In addition, the second bank layer 144 is also formed on the first bank layer 142 in the outermost region of the pixel columns, i.e., the peripheral region of the first group GR1 and the peripheral region of the nth group GRn. The third bank layer 146 is formed on the first bank layer 142 between the group GR1 and the group GR2 of the same pixel p (r).

The first bank layer 142, the second bank layer 144, and the third bank layer 146 are a kind of partition walls. The first bank layer 142 electrically separates each pixel from other pixels such that an image signal different from that of the other pixels is input to each pixel, thereby causing each pixel to display an image corresponding to the corresponding pixel. In addition, the second bank layer 144 may separate pixels of different colors to prevent light of a specific color output from neighboring pixels from being mixed and output. Further, the third bank layer 146 divides the pixels of the same color into a set number of groups such that the organic light emitting layers are continuously formed in the pixels included in the respective groups.

In the drawing, it is illustrated that a first bank layer 142 is formed on the protective layer 116, and a second bank layer 144 and a third bank layer 146 are formed on the first bank layer 142. Further, in the drawing, it is illustrated that the second and third bank layers 144 and 146 are formed to have a smaller width than the first bank layer 142 such that both sides of the upper surface of the first bank layer 142 (i.e., portions of the upper surface extending from both side surfaces of each of the second and third bank layers 144 and 146) are exposed to the outside. Here, the height of the third bank layer 146 may be greater than the height of the first bank layer 142. The height of the third bank layer 146 may be less than the height of the second bank layer 144. In addition, the width of the upper surface of the third bank layer 146 may be less than the width of the upper surface of the second bank layer 144.

The second and third bank layers 144 and 146 may be separately formed through different processes, but may be integrally formed through the same process.

The organic light emitting element E is formed on the protective layer 116 in the region partitioned by the first bank layer 142, and is connected to the drain electrode 128 of the driving thin film transistor Td through a contact hole 116a formed in the protective layer 116.

The organic light emitting element E includes a first electrode 130 connected to the drain electrode 128 of the driving thin film transistor Td through the contact hole 116a, an organic light emitting layer 132 formed on the first electrode 130, and a second electrode 134 formed on the organic light emitting layer 132.

The first electrode 130 is formed in a single layer or a plurality of layers made of a metal such as Ca, Ba, Mg, Al, or Ag, or an alloy thereof, and is connected to the drain electrode 128 of the driving thin film transistor Td, thereby applying an image signal from the outside to the first electrode 130. Here, the first electrode 130 may function as a reflective film to reflect light emitted from the organic light emitting layer 132 in an upward direction (i.e., in a direction away from the first substrate 110). In addition, the first electrode 130 may be made of a transparent metal oxide such as Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO).

The second electrode 134 is made of a transparent metal oxide such as ITO or IZO, but the present invention is not limited thereto. In addition, the second electrode 134 may be formed as a single layer or a multi-layer made of a metal such as Ca, Ba, Mg, Al, or Ag, or an alloy thereof. Here, the second electrode 134 may function as a reflective film to reflect light emitted from the organic light emitting layer 132 in a downward direction (i.e., in a direction toward the first substrate 110).

When the organic light emitting display device 100 according to the present invention is a bottom emission display device in which light emitted from the organic light emitting layer 132 is output in a downward direction, i.e., toward the first substrate 110, the first electrode 130 is made of a transparent metal oxide and the second electrode 134 is made of a metal or a metal compound that reflects light, whereas when the organic light emitting display device 100 is a top emission display device in which light emitted from the organic light emitting layer 132 is output in an upward direction, the first electrode 130 is made of a metal or a metal compound that serves as a reflective film and the second electrode 134 is made of a transparent metal oxide.

The organic light emitting layer 132 may be one of an R organic light emitting layer, a G organic light emitting layer, and a B organic light emitting layer formed in R, G and the B pixel to emit red, green, and blue light, respectively, and the organic light emitting layer 132 may be a white organic light emitting layer formed over the entire display device to emit white light. When the organic light emitting layer 132 is a white organic light emitting layer, R, G and B color filter layers are formed in R, G and an upper region of the white organic light emitting layer of the B pixel to convert white light emitted from the white organic light emitting layer into red, green, and blue light. The white organic light emitting layer may be formed by mixing a plurality of organic materials each emitting one of red, blue and green monochromatic light or may be formed by stacking a plurality of organic light emitting layers each emitting one of red, blue and green monochromatic light.

The organic light emitting layer may be an inorganic light emitting layer made of an inorganic light emitting material such as quantum dots or the like instead of the organic light emitting material.

The organic light emitting layer 132 may include a light emitting layer, an electron injection layer and a hole injection layer that inject electrons and holes into the light emitting layer, respectively, and an electron transport layer and a hole transport layer that transport the injected electrons and holes to the light emitting layer, respectively.

The first electrode 130 is formed to be spaced apart from the first bank layer 142 by a predetermined distance. However, the first electrode 130 may also be formed on the protective layer 116 on which the first bank layer 142 is formed, and thus the first bank layer 142 may be formed on the first electrode 130.

As described in detail below, the organic light emitting layer 132 may not be formed by a thermal deposition method, but the organic light emitting layer 132 may be formed by coating an organic light emitting material in a solution state on the first electrode 130, followed by drying. The organic light emitting layer 132 may be an R organic light emitting layer, a G organic light emitting layer, and a B organic light emitting layer formed in R, G and the B pixel, respectively, to emit red, green, and blue light.

Although the organic light emitting layer 132 is illustrated as being formed on one pixel P in the drawings as described below, in reality, the organic light emitting layer 132 is formed over a plurality of identical pixels P arranged in a stripe shape from one side of the display device to the other side of the display device.

Therefore, the organic light emitting layer 132 is not formed to have a constant thickness in the plurality of pixels P, and has a thickness variation between the peripheral region and the central region of the display device. The reason for this thickness variation is that the organic light emitting layer 132 is formed by coating and drying, not by a thermal deposition method.

That is, when the organic light emitting material in a solution state is coated and dried, the solvent in the organic light emitting material evaporates and the organic light emitting material remains, and in this case, the evaporation rate of the solvent in the peripheral region of the display device is greater than that in the central region of the display device, so that the organic light emitting material in the peripheral region of the display device is dried first. Therefore, a portion of the organic light emitting material in the central region that is not dried is dispersed to the peripheral region, thereby generating a thickness variation between the peripheral region and the central region of the display device.

Here, as shown in fig. 3A, the first bank layer 142 is formed in a boundary between a plurality of pixels p (r) of the same color arranged in a stripe-shaped pixel column to separate each pixel p (r), and the third bank layer 146 is disposed in a column of the plurality of pixels p (r) of the same color arranged in a stripe shape to separate the stripe-shaped pixel column into a plurality of groups GR1 and GR 2.

Further, as shown in fig. 3B, a first bank layer 142 is formed at a boundary between all pixels P to define an area of the pixels P, and a second bank layer 144 is disposed in a boundary between the pixels P (r) and P (g) of different colors to separate the pixels P (r) and P (g) of different colors. Accordingly, the organic light emitting layers 132 of different colors are formed with the second bank layer 144 interposed between the organic light emitting layers 132 of different colors, and the second bank layer 144 prevents the organic light emitting materials of different colors from being mixed when the organic light emitting layers 132 are formed.

Accordingly, although the organic light emitting layers 132 of the same color are formed with the third bank layer 146 interposed between the organic light emitting layers 132 of the same color, the organic light emitting layers 132 of the same color in the pixel columns are continuously formed across the boundary between the pixels p (r), i.e., the first bank layer 142, in each of the groups GR1 and GR2, but are disconnected by the third bank layer 146 and are discontinuously formed at the boundary between the group GR1 and the group GR 2. In particular, the third bank layer 146 allows the organic light emitting layer 132 to be formed with a uniform thickness over the plurality of pixels P arranged in the pixel column by breaking the organic light emitting layer 132 at the boundary between the group GR1 and the group GR 2.

An encapsulation layer 164 is formed on the second electrode 134. The encapsulation layer 164 may be formed as a single layer of an inorganic layer, may be formed as a double layer of an inorganic layer/an organic layer, or may be formed as three layers of an inorganic layer/an organic layer/an inorganic layer. The inorganic layer may be made of inorganic material such as SiNx and SiX, but the present invention is not limited thereto. In addition, the organic layer may be made of an organic material such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyvinylsulfonate, polyoxymethylene, polyarylate or a mixture thereof, but the present invention is not limited thereto.

An adhesive layer 162 is coated on the encapsulation layer 164 and the second substrate 160 is disposed on the adhesive layer 162, and thus the second substrate 160 is attached to the display device. Further, although not shown in the drawings, at least one layer of a package is provided over the organic light emitting element E to encapsulate the organic light emitting element E, so that impurities such as air and moisture can be prevented from penetrating into the organic light emitting element E, and as a result, deterioration of the organic light emitting element E and causing defects in the organic light emitting element E can be prevented.

The encapsulation may be formed as one layer of an inorganic encapsulation layer, or may be formed as multiple layers of an inorganic encapsulation layer/an organic encapsulation layer/an inorganic encapsulation layer. The inorganic encapsulation layer may be made of an inorganic material such as SiNx and SiX, but the present invention is not limited thereto. Further, as the organic encapsulation layer, an organic material such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyvinyl sulfonate, polyoxymethylene, polyarylate or a mixture thereof may be used, but the present invention is not limited thereto.

Any material may be used as the adhesive layer 162 as long as the material has high adhesion, heat resistance, and water resistance, but in the present invention, a thermosetting resin such as an epoxy-based compound, an acrylate-based compound, or an acrylic rubber may be used. Further, a photocurable resin may be used as the adhesive, in which case the adhesive layer 162 is cured by irradiating light thereto such as ultraviolet rays.

The adhesive layer 162 may not only bond the first substrate 110 and the second substrate 160, but also serve as a package for preventing moisture from penetrating into the organic light emitting display device 100. Therefore, although the reference numeral "162" is expressed as an adhesive layer in the detailed description of the present invention, this is for convenience of description, and the adhesive layer may also be referred to as another encapsulation layer.

As the second substrate 160 serving as an encapsulation cap (encapsulation cap) encapsulating the organic light emitting display device 100, a protective film such as a Polystyrene (PS) film, a Polyethylene (PE) film, a polyethylene naphthalate (PEN) film, or a Polyimide (PI) film, or glass may be used.

The first electrode 130 is a cathode of the organic light emitting element, the second electrode 134 is an anode of the organic light emitting element, when a voltage is applied to the first electrode 130 and the second electrode 134, electrons are injected from the first electrode 130 into the organic light emitting layer 132, and holes are injected from the second electrode 134 into the organic light emitting layer 132, so that excitons are generated in the organic light emitting layer 132, and as the excitons decay, light corresponding to an energy difference between a lowest unoccupied molecular orbital (L UMO) and a Highest Occupied Molecular Orbital (HOMO) of the light emitting layer is generated, and emitted to the outside.

As described above, in the organic light emitting display device 100 according to the present invention, the organic light emitting layer 132 formed in the pixel columns may be formed to have a uniform thickness by dividing the pixel columns into a plurality of groups GR1, GR 2.. and GRn by forming at least one third bank layer 146 in the pixel columns in which the pixels of the same color are arranged in a stripe shape.

Fig. 4 is a flowchart illustrating a method of manufacturing the organic light emitting display device 100 according to the present invention.

As shown in fig. 4, first, a buffer layer 112 is formed on the first substrate 110, and then a driving thin film transistor Td composed of a semiconductor layer 122, a gate insulating layer 123, a gate electrode 125, an interlayer insulating layer 114, a source electrode 127, and a drain electrode 128 is formed on the buffer layer 112 (S101).

Thereafter, the protective layer 116 is formed by stacking an organic material such as an optical acryl on the entire first substrate 110 on which the driving thin film transistor Td is formed (S102), and then the first, second, and third bank layers 142, 144, and 146 are formed on the protective layer 116 (S103).

Here, the first bank layer 142 is formed in the lateral and longitudinal directions of the first substrate 110 and is disposed along the periphery of each of all the pixels P of the organic light emitting display device 100 so as to separate each of all the pixels P from other pixels P. The second bank layer 144 is formed along the periphery of the first substrate 110 to separate the pixels from the peripheral region, and the second bank layer 144 is formed along the longitudinal direction of the first substrate 110 to separate the pixels P of the same color from the pixels P of other colors. Further, the third bank layer 146 is disposed in a boundary between pixels of a pixel column in a longitudinal direction of the first substrate 110 to divide the pixel column into a plurality of groups.

Thereafter, the first electrode 130 is formed in each pixel defined by the first bank layer 142 (S104), and then an organic light emitting material is coated and cured to form the organic light emitting layer 132(S105 and S106).

Here, the first electrodes 130 are formed in units of the first bank layers 142, that is, in units of pixels, such that the first electrodes 130 are separated from each other at boundaries between adjacent pixels, but the organic light emitting layers 132 are formed in units of the second bank layers 144 and the third bank layers 146, that is, in units of groups formed in pixel columns, such that the organic light emitting layers 132 are continuously formed in a plurality of pixels arranged in the longitudinal direction, but are disconnected at boundaries between the groups.

After that, the organic light emitting display apparatus 100 is completed by forming the second electrode 134 on the organic light emitting layer 132 and then encapsulating the organic light emitting display apparatus 100(S107 and S108).

As described above, in the organic light emitting display device 100 according to the present invention, the organic light emitting layer 132 is formed by coating an organic light emitting material in a group partitioned by the first bank layer 142, the second bank layer 144, and the third bank layer 146, followed by drying (or curing), and a method of coating an organic light emitting material will be described with reference to fig. 5.

Fig. 5 is a view illustrating a method of coating an organic light emitting material in an organic light emitting display device according to the present invention. Here, for convenience of description, only the first, second, and third bank layers 142, 144, and 146 are shown on the first substrate 110, and other components such as a thin film transistor are omitted.

As shown in fig. 5, a plurality of R pixels, a plurality of G pixels, and a plurality of B pixels are formed on the first substrate 110, the pixels of the same color are arranged in a stripe shape along a first direction (i.e., along a longitudinal direction) of the first substrate 110, and the pixels of different colors are alternately arranged in a stripe shape along a second direction (i.e., along a lateral direction) of the first substrate 110 different from the first direction (R-G-B-R-G-B).

The first bank layer 142 is formed in the first and second directions of the first substrate 110 to surround all R, G and B pixels, and the second bank layer 144 is formed on the first bank layer 142 in the first direction and disposed in boundaries between pixels of different colors, i.e., between R and G pixel columns, between G and B pixel columns, and between B and R pixel columns. Further, a plurality of third bank layers 146 are formed on the first bank layer 142 in the second direction in each of the R, G, and B pixel columns such that each of the R, G, and B pixel columns is divided into a plurality of groups GR1, GR2,. and GRn. Here, each of the groups GR1, GR 2.. and GRn includes a plurality of pixels of a respective color.

At this time, the second and third bank layers 144 and 146 are integrally formed of the same material, but may be separately formed of different materials (but all materials have hydrophobicity).

After the first, second, and third bank layers 142, 144, and 146 are formed, dispensing devices such as first to third dispensers 180R, 180G, and 180B filled with R organic light emitting material 182R, G organic light emitting material 182G and B organic light emitting material 182B, respectively, are positioned on the pixel columns separated by the second and third bank layers 144 and 146, that is, on the R, G, and B pixel columns, and then set amounts of the organic light emitting materials 182R, 182G, and 182B are dispensed on each pixel column for a set time.

Here, each of the R, G, and B pixel columns is divided into a plurality of groups GR1, GR2,. and GRn, and first to third distributors 180R, 180G, and 180B are arranged on each of the plurality of groups to distribute the R organic light emitting material 182R, G organic light emitting material 182G and the B organic light emitting material 182B in each of these groups GR1, GR2,. and GRn, respectively.

That is, the first distributor 180R is disposed on each of the plurality of groups GR1, GR 2.. and GRn of the R pixel columns to distribute the R organic light emitting material 182R in each of the respective groups GR1, GR 2.. and GRn. Further, after the first dispenser 180R is disposed on one of the plurality of groups GR1, GR 2.. and GRn of the R pixel columns to dispense the R organic luminescent material 182R in the one of the plurality of groups GR1, GR 2.. and GRn, the first dispenser 180R may move onto the other groups GR1, GR 2.. and GRn to dispense the R organic luminescent material 182R therein. That is, the R organic light emitting materials 182R may be simultaneously dispensed or sequentially dispensed in the plurality of groups GR1, GR2,. and GRn of the R pixel columns.

Further, the G organic luminescent materials 182G and the B organic luminescent materials 182B may also be simultaneously dispensed or sequentially dispensed in the plurality of groups GR1, GR2,. and GRn of the G pixel columns and the plurality of groups GR1, GR2,. and GRn of the B pixel columns by the second dispenser 180G and the third dispenser 180B, respectively.

Here, although not shown in the drawings, each of the first to third dispensers 180R, 180G and 180B is provided with a nozzle, which is turned on and off for a set time, so that a desired amount of organic light emitting materials 182R, 182G and 182B can be dispensed on the first substrate 110. At this time, the nozzles of the first to third dispensers 180R, 180G and 180B may be driven in a short time so that the organic light emitting materials 182R, 182G and 182B in a droplet shape may be dispensed multiple times, or the organic light emitting materials 182R, 182G and 182B may be dispensed in a dummy form (dummy) at a time in a predetermined amount. The first to third distributors 180R, 180G and 180B distribute the set amounts of organic light emitting materials 182R, 182G and 182B in which different driving times or driving frequencies are set, respectively, on the corresponding pixel rows.

As described above, by dispensing the organic light emitting material on one pixel column, the organic light emitting layer can be rapidly formed even in the organic light emitting display device 100 having a large area. In particular, in the present invention, since the organic light emitting material is allocated for each group, the organic light emitting layer can be formed more quickly.

Meanwhile, in the present invention, the means for dispensing the organic light emitting materials 182R, 182G, and 182B on the substrate is not limited to the above-described dispenser, but various coating means such as a slit coater for discharging the organic light emitting materials 182R, 182G, and 182B into desired positions through slits and a drop coater for dropping a certain amount of the organic light emitting materials 182R, 182G, and 182B may be used.

The organic light emitting materials 182R, 182G, and 182B allocated in each of the groups GR1, GR2,. and GRn of pixel columns are dispersed along the pixel columns arranged in the first direction, and thus an organic light emitting layer is formed in each of the groups GR1, GR2,. and GRn.

As described above, an organic light emitting layer having a uniform thickness may be formed by forming an organic light emitting layer for each of a plurality of groups GR1, GR2,. and GRn formed in a pixel column, which will be described in more detail below.

The plurality of pixels P arranged in the organic light emitting display device may be formed to be completely separated from each other. That is, the organic light emitting layer formed in each pixel P may be completely separated from the organic light emitting layers of the other pixels P.

In the organic light emitting display device having such a structure, when the organic light emitting layer is formed, an organic light emitting material in a solution state is dispensed on each pixel P and then dried to form the organic light emitting layer. That is, the organic light emitting layer is formed by directly dispensing the organic light emitting material onto each of all R, G and B pixels using the dispensers 180R, 180G, and 180B shown in fig. 5.

At this time, since a large number of pixels P are formed in the organic light emitting display device, in order to rapidly form the organic light emitting layer, a plurality of dispensers 180R, 180G, and 180B should be provided to dispense the organic light emitting material on the pixels P. In other words, in order to dispense the organic light emitting material on the pixels P of different colors, in addition to preparing the plurality of dispensers 180R, 180G, and 180B filled with the organic light emitting materials of different colors, a plurality of dispensers filled with the organic light emitting materials of the same color should be prepared.

However, the amount of one droplet of the organic luminescent material dispensed from the plurality of dispensers 180R, 180G, and 180B varies due to a variation in the shape of the nozzle, a variation in the opening and closing time of the nozzle, and the amount of the organic luminescent material filled inside the dispenser (pressure applied to the organic luminescent material dispensed through the nozzle). Due to such a variation in the amount of one droplet, a difference is generated in the amount of coating of the organic light emitting material dispensed onto each pixel P. Accordingly, the thickness of the manufactured organic light emitting layer is different for each pixel P, and thus each pixel of the organic light emitting display device generates a difference in visual sensitivity, thereby causing a defect of the organic light emitting display device.

On the other hand, in the present invention, a plurality of pixels P in a pixel column are divided into one group, an organic light emitting material is allocated in each group, and the organic light emitting material is dispersed and coated in the group, so that a much larger amount of organic light emitting material is allocated in each group as compared with allocation in one pixel P. Therefore, even when the amount of one droplet is changed, the change in the amount of one droplet can be compensated by dispensing a large number of times, thereby minimizing the thickness variation of the organic light emitting layer formed in each pixel P.

Table 1 is a table showing an average amount of change in the amount of organic light emitting material coated on one pixel with respect to the number of pixels included in each of the plurality of groups GR1, GR2,. and GRn, and fig. 6 is a graph illustrating an average amount of change in the amount of organic light emitting material coated on one pixel with respect to the number of pixels included in each of the plurality of groups GR1, GR2,. and GRn.

Here, assuming that the amount of one droplet dispensed from one nozzle is 10.5pl (picoliter), the amount of each droplet exhibits an error of ± 10%, and the organic light emitting material is dispensed 10 times in each pixel.

[ Table 1]

As shown in table 1, when there is one pixel in the group, that is, each pixel is separated from other pixels, and the organic light emitting material is dispensed on each pixel, the average variation amount of the organic light emitting material is about 6.392279 pl.

Further, when there are two pixels in a group, the average variation is about 3.232262pl, and when there are eight pixels in a group, the average variation is about 1.389546 pl. When there are 20 pixels in a group, the average variation is about 0.759987pl, i.e., the average variation decreases as the number of pixels in the group increases.

As shown in fig. 6, as the number of pixels in a group increases from one, the average variation amount of the organic light emitting material initially decreases rapidly, and then the rate of decrease in the average variation amount gradually decreases. In particular, the average change in pixels is rapidly reduced a first time until the number of pixels in the group increases to eight, and then rapidly reduced a second time until the number of pixels in the group increases to 21. Thereafter, when the number of pixels in the group increases from 21 to 100, the average variation amount slowly decreases.

Therefore, in the present invention, the maximum effect can be achieved by setting the number of pixels P arranged in each of the groups GR1, GR2,. and GRn to eight or 21. Of course, for example, the number of pixels of each of the groups GR1, GR 2.. and GRn may be 10, 11, 40 or 60, but at this time, a drastic reduction in the average amount of change in the organic light emitting materials may be undesirable as compared with a case where the number of pixels of each of the groups GR1, GR 2.. and GRn is eight or 21.

In addition, as the number of pixels included in each of the groups GR1, GR 2.. and GRn increases, the variation in the dispensing amount of the organic light emitting material in the pixels decreases. Therefore, it is possible to minimize the variation in the distribution amount of the organic light emitting material of the pixels by forming the entire pixel columns into one group and distributing the amount of the organic light emitting material corresponding to the organic light emitting layer formed in the entire pixel columns, but such a structure may cause the following other problems. For example, when the resolution of the display device is 1080P, 1080 pixels P are arranged in each pixel column formed in the longitudinal direction, and thus the organic light emitting material dispensed in a predetermined region is dispersed and coated on the entire 1080 pixels P.

Generally, when a solution is coated, the stress is caused by the van der waals forces of the solution. However, when the organic light emitting material in the form of a solution is coated on the entire pixel column of the wide region, stress acts on the entire wide region, and thus the organic light emitting material in the outermost region of the pixel column flows to the central region of the pixel column due to the stress, so that the organic light emitting material is very thinly coated in the outermost region or is not even coated in the outermost region.

Further, when the organic light emitting material is dried, this phenomenon becomes worse, and as a result, an uncoated region where the organic light emitting material is not coated is generated in the peripheral region of the pixel column, and when the organic light emitting material is completely dried, the organic light emitting layer is not formed in the outermost region. Therefore, mura defects in which an image is not displayed at the upper and lower ends of the completed organic light emitting display device are generated.

On the other hand, in the present invention, the pixel columns are divided into a plurality of groups GR1, GR 2.. and GRn by the third bank layer 146, and a much smaller number (e.g., eight or 20) of pixels p (r) than the pixels p (r) of the entire pixel column are arranged in each of these groups GR1, GR 2.. and GRn. Therefore, when the organic light emitting material 182R is dispensed and coated on each of the divided groups GR1, GR2,. and GRn, stress acts only on the organic light emitting material 182R in each of the divided groups GR1, GR2,. and GRn, and thus the intensity of the stress becomes much smaller than the case where the stress acts on the entire pixel column.

Accordingly, in the groups GR1, GR2,. and GRn, the organic light emitting materials in the peripheral regions of the groups GR1, GR2,. and GRn do not flow into the central region due to the weak stress of the organic light emitting material 182R, and thus the organic light emitting materials are coated in a uniform thickness over the entire regions of the groups GR1, GR2,. and GRn, and as a result, the organic light emitting layer 132 having a uniform thickness can be formed over the entire pixel columns and the organic light emitting display device 100.

Fig. 7A and 7B are graphs illustrating thicknesses of organic light emitting layers measured at two specific points in one pixel column in an organic light emitting display device in which pixel columns are not grouped and in an organic light emitting display device according to the first embodiment of the present invention in which pixel columns are grouped, respectively. Here, the horizontal axis represents the width of a pixel (or a pixel column), and the vertical axis represents the thickness of the organic light emitting layer.

As shown in fig. 7A, in the organic light emitting display device in which pixel columns are not grouped, a thickness difference of about 20-25nm occurs between two points of the organic light emitting layer over the entire width of the pixels.

On the other hand, as shown in fig. 7B, in the organic light emitting display device 100 according to the first embodiment of the present invention, the thicknesses of the organic light emitting layers at two points are almost the same over the entire width of the pixel.

As described above, in the organic light emitting display device 100 according to the first embodiment of the present invention, the organic light emitting layer is formed by dispensing the organic light emitting material in a solution state on the plurality of pixels grouped into the plurality of groups, instead of forming the organic light emitting layer separated from the organic light emitting layers of the other pixels by dispensing the organic light emitting material in a solution state on each pixel. Therefore, even when the amount of one droplet dispensed from the dispensing device varies, since the organic light emitting material is dispensed a large number of times corresponding to a plurality of pixels, the variation in the dispensing amount generated in one droplet can be compensated, thereby minimizing the variation in the thickness of the organic light emitting layer formed in each pixel.

Further, in the organic light emitting display device 100 according to the first embodiment of the present invention, the pixel columns are divided into a plurality of groups by forming at least one third bank layer 146 in the pixel columns, and then an organic light emitting material is dispensed in each group to form an organic light emitting layer in each group. Therefore, as compared with a case where the organic light emitting material in a solution state is dispensed on a set region of the pixel column and the organic light emitting material is coated on the entire pixel column, stress of the organic light emitting material can be reduced, and thus mura defect caused by non-formation of the organic light emitting layer in an outermost region of the pixel column due to the stress can be prevented.

As described above, the present invention can solve the problems caused by forming an organic light emitting layer in one pixel and the problems caused by forming an organic light emitting layer in a large number of pixel columns. That is, in order to solve all the problems caused by forming the organic light emitting layer in a large number of pixel columns, in the present invention, the pixel columns are divided into a plurality of groups, and the number of pixels included in the divided groups is set to the number that can maximize the effect of reducing the variation in the amount of droplets, so that the problems caused by the variation in the amount of droplets and the stress of the organic light emitting material can be effectively solved as much as possible.

Meanwhile, in the organic light emitting display device 100 according to the first embodiment of the present invention, each of the groups GR1, GR 2.. and GRn includes eight or 21 pixels P, but the present invention is not limited thereto, and other numbers of pixels may be included in each of the groups GR1, GR 2.. and GRn according to a variation in the dispensing amount of the dispensing device and the type of organic light emitting material.

Further, the groups GR1, GR2,. and GRn formed in each pixel column of the organic light emitting display device 100 according to the first embodiment of the present invention may not include the same number of pixels, but may include different numbers of pixels according to regions. For example, the number of pixels P arranged in a group of peripheral regions of a pixel column (i.e., GR1, GR2,. yet, GRn-1, and Gn) may be different from the number of pixels P arranged in a group of central regions of a pixel column (i.e., GRn/2-1, GRn/2, and GRn/2+1,. yet).

In general, when an organic light emitting material is coated and then dried, the drying rate differs according to the position of a pixel column. This difference in drying rate is determined by the ambient atmosphere. For example, as drying continues, the solvent evaporates from the coated organic light emitting material, so that the ambient atmosphere of the coated organic light emitting material is filled with an evaporation gas having a constant concentration of the solvent. Here, the solvent concentration of the atmosphere around the central region of the pixel column is high due to the continuous evaporation in the peripheral region, whereas the solvent concentration in the peripheral region of the pixel column is relatively low because the evaporation occurs only on one side of the peripheral region. Therefore, when the drying is continuously performed, the evaporation rate of the solvent, i.e., the drying rate, is decreased in the central region, and the drying rate is increased in the peripheral region.

The increase in the drying rate increases the density of the organic light emitting material in a solution state, thereby increasing cohesion (cohesion) in the organic light emitting material. Of course, a phenomenon in which the organic light emitting material is not coated in the outermost region of the groups GR1, GR2,. and GRn due to the cohesive force of the organic light emitting material does not occur in each of the groups GR1, GR2,. and GRn divided by the third bank layer 146, and variation in the coating thickness of the organic light emitting material hardly occurs in the central region and the peripheral region of the groups GR1, GR2,. and GRn. In particular, the variation in the coating thickness of the organic light emitting material arranged in the group in the peripheral region where the drying rate of the pixel column is high is larger than the variation in the coating thickness of the organic light emitting material arranged in the central region of the pixel column.

Therefore, in the present invention, in consideration of the drying rate between the group of the peripheral region of the pixel columns and the group of the central region of the pixel columns, the number of pixels arranged in the group of the peripheral region is smaller than the number of pixels arranged in the group of the central region, thereby reducing the thickness variation due to the drying rate.

In other words, by reducing the number of pixels in the group of the peripheral region having a higher drying rate, an increase in cohesive force due to the drying rate in the corresponding region is offset by a reduction in the coating area of the organic light emitting material in a solution state, and thus, a change in the coating thickness of the organic light emitting material can be prevented from becoming significantly increased compared to the central region.

For example, two groups (e.g., GR1 and GR2, and GRn-1 and GRn) of the peripheral region of each of the upper and lower ends may be formed to include eight pixels, and groups (GR3,.., GRn-2) of the central region other than the two groups may be formed to include 21 pixels. Here, the number of pixels included in the group of the peripheral region and the group of the central region is not limited to a specific number. Further, the number of pixels grouped continuously or discontinuously may be increased from the peripheral area toward the central area.

Fig. 8 is a plan view of an organic light emitting display device 200 according to a second embodiment of the present invention. As shown in fig. 8, in the organic light emitting display device 200 of the present embodiment, the arrangement of pixels included in a group may be formed differently according to pixel columns P1, P2, P3. For example, eight pixels are provided in each of a plurality of groups GR11, GR12,. and GR1n arranged in odd-numbered pixel columns (P1, P3,. and GR1 n), and 5, 8, …, 8 and 4 pixels are provided in each of a plurality of groups GR21, GR22,. and GR2n arranged in even-numbered pixel columns (P2, P4,. and..) respectively, so that the third bank layer 246 arranged on the boundary between the plurality of groups GR11, GR12,. and GR1n may be formed not to be adjacent in the lateral direction to the third bank layer 246 arranged on the boundary between the plurality of groups GR21, GR22,. and GR12 n in adjacent pixel columns. That is, the third bank layer 246 of one pixel column may be arranged to be misaligned with the third bank layer 246 of another pixel column adjacent in the lateral direction.

Further, the number of pixels included in a group may be formed differently according to the pixel columns P1, P2, P3,. and Pm. That is, groups corresponding to pixel columns of different colors may include different numbers of pixels. For example, each of the plurality of groups GR11, GR12,. and GR1n formed in the first pixel column P1 may include eight pixels, each of the plurality of groups GR21, GR22,. and GR2n formed in the second pixel column P2 may include four pixels, and each of the plurality of groups GR31, GR32,. and GR3n formed in the third pixel column P3 may include eight pixels, and this form of pixel column may be repeated.

Here, the number of pixels included in each group arranged in each of the pixel columns P1, P2, P3,. and Pm is not limited to a specific number of eight, four, and eight, but may be formed in various numbers. When the graph of the variation of the dispensing amount shown in fig. 6 is considered, the number of pixels included in each group arranged in each of the pixel columns P1, P2, P3,. and Pm may be limited to eight or 21.

Each of R, G and B organic light emitting layers is formed in each of the pixel columns P1, P2, P3,. and Pm. That is, organic light emitting layers of different colors are formed in pixel columns adjacent to each other. R, G and B organic light emitting materials include different kinds of phosphors or phosphorescent materials and different host materials and dopants. Therefore, since the organic light emitting materials of different colors have different compositions, the cohesion of the organic light emitting materials of different colors is also different.

In the organic light emitting display device 200 of the present embodiment, the arrangement of groups to be coated or the number of groups included in each of the pixel columns P1, P2, P3,. and Pm is differently set according to the cohesive force of the R, G and B organic light emitting materials, so that an organic light emitting layer having a uniform thickness can be formed all the time.

Fig. 9A and 9B are a plan view and a cross-sectional view illustrating the structure of an organic light emitting display device 300 according to a third embodiment of the present invention, respectively. Here, the same structure as the organic light emitting display device 100 of the first embodiment described with reference to fig. 3 will be omitted or simply described, and only the different structure will be described in detail.

As shown in fig. 9A, a plurality of R pixels, a plurality of G pixels, and a plurality of B pixels are arranged in an organic light emitting display device 300 according to a third embodiment of the present invention, and an R organic light emitting layer, a G organic light emitting layer, and a B organic light emitting layer are formed in the R pixels, the G pixels, and the B pixels, respectively. Here, the R pixels, the G pixels, and the B pixels are arranged in a stripe manner, and a plurality of the R pixels, a plurality of the G pixels, and a plurality of the B pixels are each arranged in a longitudinal direction.

The first bank layer 342 is formed at the periphery of each of the R, G, and B pixels such that each of all the R, G, and B pixels is separated from other pixels. In addition, the second bank layer 344 is disposed in a boundary between the R, G, and B pixel columns arranged in the longitudinal direction and in an outermost region of the organic light emitting display device 300 to separate pixel columns of different colors.

Although the first bank layer 342 is formed in a boundary between pixels of the same color arranged along a pixel column to separate adjacent pixels of the same color, an organic light emitting layer of a corresponding color is formed over all pixels arranged in the corresponding pixel column across the first bank layer 342.

Each of the plurality of pixel columns is divided into a plurality of groups GR1, GR2,. and GRn, and the third bank layer 346 is formed in a boundary between these groups GR1, GR2,. and GRn. Here, the third bank layer 346 is made of a hydrophilic material of the same material as the first bank layer 342. That is, in the first embodiment described with reference to fig. 2, the third bank layer 146 is made of a hydrophobic material, whereas in the present embodiment, the third bank layer 346 is made of a hydrophilic material.

The third bank layer 346 separates organic light emitting layers formed in each of a plurality of adjacent groups GR1, GR2,. and GRn. That is, organic light emitting layers having the same color are formed in the entire pixel columns, and in a plurality of pixels arranged in each of these groups GR1, GR2,. and GRn, the organic light emitting layers are continuously formed across the first bank layer 342, but between adjacent groups GR1, GR2,. and GRn, the organic light emitting layers are formed by being disconnected from each other.

As shown in fig. 9B, in the organic light emitting display device 300 of the present embodiment, the third bank layer 346 configured to divide pixel columns into a plurality of groups GR1, GR2,. and GRn is made of a hydrophilic material. In the organic light emitting display device 100 of the first embodiment, the third bank layer 146 is made of a hydrophobic material and is formed on the hydrophilic first bank layer 142, whereas in the present embodiment, the third bank layer 346 is made of a hydrophilic material and is directly formed on the protective layer 316. Here, the height of the third bank layer 346 may be greater than that of the first bank layer 342. The height of the third bank layer 346 may be less than the height of the second bank layer 344. In addition, the width of the upper surface of the third bank layer 346 may be less than the width of the upper surface of the second bank layer 344.

As described above, in this embodiment mode, by dividing pixel columns into a plurality of groups GR1, GR2,. and GRn by the third bank layer 346, an organic light emitting material may be coated on each of the plurality of groups GR1, GR2,. and GRn and dispersed in each of these groups GR1, GR2,. and GRn, and an organic light emitting layer may be coated on each of these groups GR1, GR2,. and GRn. Therefore, it is possible to solve the unevenness of the thickness of the organic light emitting material due to the variation of the amount of one droplet and the stress of the organic light emitting material.

In particular, in the present embodiment, the third bank layer 346 is made of a hydrophilic material, the height of the third bank layer 346 is smaller than the height of the second bank layer 344, and the width of the upper surface of the third bank layer 346 is smaller than the width of the upper surface of the second bank layer 344. Accordingly, although the coated organic light emitting material is not scattered to the pixels of other colors beyond the second bank layer 344, the organic light emitting material of the corresponding color may flow to another group beyond the third bank layer 346 in the pixel column of the same color.

Accordingly, since a small amount of organic light emitting material flows between adjacent groups, some organic light emitting materials are dispersed from groups coated with a larger amount of organic light emitting material to groups coated with a smaller amount of organic light emitting material in the adjacent groups, so that thickness unevenness of the organic light emitting material between pixels of the corresponding pixel columns can be more effectively solved.

Fig. 10A and 10B are a plan view and a cross-sectional view of an organic light emitting display device 400 according to a fourth embodiment of the present invention, respectively.

As shown in fig. 10A, the organic light emitting display device 400 according to the present embodiment includes a plurality of pixels P, the same color pixels P being arranged in a stripe shape along a longitudinal direction. Here, each pixel P is separated from other pixels by a first bank layer 442 having hydrophilicity, and pixel columns of different colors are separated from each other by a second bank layer 444. Further, the third bank layer 446 is formed in pixel columns of the same color to divide each pixel column into a plurality of groups GR1, GR2,. and GRn. Here, although eight or 21 pixels P may be arranged in each of these groups GR1, GR2,. and GRn, more or fewer pixels P may be arranged.

Dummy regions D1 and D2 are formed at the peripheries of the outermost groups GR1 and GRn of the pixel columns. Therefore, in the organic light emitting display device 400 of the present embodiment, the dummy regions D1 and D2 are provided on the actually outermost regions of the pixel columns. Here, the second bank layer 444 is formed in the outermost region of the dummy regions D1 and D2, and the third bank layer 446 is formed in the boundary between the dummy region D1 and the outermost group GR1 and the boundary between the dummy region D2 and the outermost group GRn to define dummy regions D1 and D2.

A plurality of virtual pixels DP are arranged in the virtual regions Dl and D2, and a first bank layer 442 is formed between the virtual pixels DP in the virtual regions Dl and D2 to separate the virtual pixels DP. Although it is shown in the drawings that a certain number of virtual pixels DP are disposed in the virtual areas D1 and D2, the number of virtual pixels DP is not limited to the certain number. For example, the number of virtual pixels DP arranged in the virtual regions D1 and D2 may be the same as or different from the number of pixels P arranged in the groups GR1, GR 2.

As shown in fig. 10B, the organic light emitting display device 400 according to the present embodiment includes a group GR1 having a plurality of pixels P and a virtual region D1 disposed at the periphery of the group GR1 and having a plurality of virtual pixels DP arranged therein. Here, the first bank layers 442 are formed between the pixels P in the group GR1 and between the dummy pixels DP in the dummy region D1, and the second bank layers 444 are formed on the first bank layers 442 in the boundaries between the pixel columns of different colors and in the outermost portions of the pixel columns. The third bank layer 446 is formed on the first bank layer 442 between the dummy region D1 and the group GR 1.

Here, the first bank layer 442 is made of a hydrophilic material, and the second bank layer 444 and the third bank layer 446 are made of a hydrophobic material. The second and third bank layers 444 and 446 may be integrally formed through the same process or may be separately formed through different processes.

In the organic light emitting display device 400 of the present embodiment, pixel columns are also divided into a plurality of groups GR1, GR 2.. and GRn, and an organic light emitting material is allocated in each of these groups GR1, GR 2.. and GRn to be dispersed and coated in each of these groups GR1, GR 2.. and GRn, so that the organic light emitting material can be coated in a uniform thickness as a whole.

Since the dummy region D1 is not a region where an image is actually realized, the driving thin film transistor Td and the light emitting element E are formed in each of the plurality of pixels P in the group GR1, and the driving thin film transistor Td and the first electrode 430 are not formed in the dummy pixel DP of the dummy region D1.

However, the organic light emitting layer 432 is formed in the dummy pixel DP of the dummy area D1. This is to make the drying conditions of the peripheral regions (i.e., the groups GR1 and GRn of the peripheral regions) and the central region of the pixel columns the same when drying the organic light emitting layer 432. That is, by coating the organic light emitting material on the dummy pixels DP, when the organic light emitting material is dried, the organic light emitting material in the groups GR1 and GRn in the peripheral region is evaporated, and thus the atmosphere of the groups GR1 and GRn in the peripheral region, that is, the solvent concentration in the upper region and the lower region, becomes the same as the atmosphere in the central region, and the drying rate of the organic light emitting material in the peripheral region and the central region of the pixel columns is the same, so that the organic light emitting layer having a more uniform thickness can be formed in the peripheral region and the central region of the pixel columns.

The second electrode 434 is formed in the dummy region Dl, but the second electrode 434 may not be formed. Further, the driving thin film transistor Td and the light emitting element E may be formed in the dummy area D1, but in this case, the driving thin film transistor Td and the light emitting element E are not driven.

Fig. 11 is a view illustrating an organic light emitting display device 500 according to a fifth embodiment of the present invention.

Similar to the structure shown in fig. 10A, the organic light emitting display device 500 having the present structure includes pixel columns each having a plurality of groups GR1, GR2,. and GRn, and dummy regions D1 and D2 at the periphery of the pixel columns. Here, in the organic light emitting display device 500 having the present structure, only the first bank layer 542 is formed and the third bank layer 546 is not formed in the boundary between the dummy region D1 and the outermost group GR1 and the boundary between the dummy region D2 and the outermost group GRn.

Even in such a structure, since only the organic light emitting layers are formed in the dummy regions Dl and D2, but the thin film transistors and electrodes are not formed in the dummy regions Dl and D2, when the organic light emitting materials are coated and dried, the drying rate in the outermost groups GR1 and GRn can be made the same as the drying rate in the central region by making the drying atmosphere of the outermost groups GR1 and GRn the same as the drying atmosphere of the central region.

Further, in the organic light emitting display device 500 having the present structure, since the third bank layer 546 is not disposed in the boundary between the dummy region D1 and the outermost group GR1 and the boundary between the dummy region D2 and the outermost group GRn, the light emitting materials allocated in the outermost groups GR1 and GRn are dispersed to the dummy regions D1 and D2. Therefore, when the thickness of the organic light emitting material coated in the peripheral region in the outermost groups GR1 and GRn becomes small, or even when the organic light emitting material is not coated due to stress of the organic light emitting material, since such a phenomenon occurs in the dummy regions D1 and D2 where no image is displayed, mura defect does not occur in the actually completed organic light emitting display device 500.

Fig. 12 is a view illustrating an organic light emitting display device 600 according to a sixth embodiment of the present invention.

Similar to the organic light emitting display device 500 having the structure shown in fig. 11, in the organic light emitting display device 600 having the present structure, the third bank layer 646 is not disposed in the boundary between the dummy region D1 and the outermost group GR1 and the boundary between the dummy region D2 and the outermost group GRn, so that the organic light emitting materials allocated in the outermost groups GR1 and GRn are dispersed to the dummy regions D1 and D2.

In particular, in the organic light emitting display device 600 having the present structure, some of the pixels P included in the outermost groups GR1 and GRn are set as the virtual areas D1 and D2 in which no image is realized or an image is covered by a housing or the like. Therefore, in the organic light emitting display device 600 having the present structure, the number of pixels arranged in the outermost groups GR1 and GRn to realize an actual image is different from the number of pixels arranged in the other groups. The sum of the number of dummy pixels in the dummy area adjacent to the outermost group and the number of pixels in the outermost group may be equal to the number of pixels of the other group.

Even in the organic light emitting display device 600 having the present structure, when the thickness of the organic light emitting material coated in the peripheral region in the outermost groups GR1 and GRn becomes small, or even when the organic light emitting material is not coated due to stress of the organic light emitting material, since the region where such a phenomenon occurs is a region where an image is not realized or an image is blocked by a case or the like, a mura defect does not occur in the actually completed organic light emitting display device 600.

Although the thin film transistor and the light emitting element are formed in the dummy pixel DP of the dummy regions D1 and D2, it is possible to prevent an image from being implemented in the dummy regions D1 and D2 by not applying signals to the thin film transistor and the light emitting element or by turning off the electrodes.

Further, even if signals are applied to the thin film transistors and the light emitting elements of the dummy pixels DP in the dummy regions Dl and D2, images of the dummy regions Dl and D2 may be prevented from being displayed on the screen of the completed organic light emitting display device by shielding the dummy regions D1 and D2 with a housing.

In the present invention, since the organic light emitting material is coated to form the organic light emitting layer using a coating method instead of a thermal deposition method, the process can be rapidly performed, the manufacturing cost can be reduced, and a large-area organic light emitting display device can be manufactured.

Further, in the present invention, since each pixel column is divided into a plurality of groups each including a plurality of pixels, and the organic light emitting material in a solution state is dispensed in each group, even when a variation in the dispensing amount occurs in one droplet, the variation in the dispensing amount can be compensated for by dispensing a large amount of the organic light emitting material over the plurality of pixels. Therefore, it is possible to prevent the formation of the organic light emitting layer having a non-uniform thickness due to the variation in the amount of one droplet.

Further, by configuring the number of pixels included in one group so that stress does not occur in the organic light emitting material in a solution state, it is possible to prevent the organic light emitting layer from being formed with uneven thickness due to the stress of the organic light emitting material.

While various aspects have been described in detail in the foregoing description, this should be construed as illustrative of exemplary embodiments and not as limiting the scope of the invention. Accordingly, the invention is not to be limited by the described embodiments, but by the claims and their equivalents.