KR100773939B1 - Organic electro luminescent display device - Google Patents

Abstract

The present invention relates to an organic electroluminescent device capable of solving the non-uniformity of the luminance due to the voltage drop phenomenon of the positive electrode layer and maximizing the thermal and electrical stabilization and particle removal effect of the device by the aging process.

Such an organic electroluminescent device of the present invention comprises: a plurality of positive electrode layers arranged in a stripe shape on a transparent substrate; An organic thin film layer formed on the plurality of positive electrode layers; A plurality of negative electrode layers arranged in a stripe shape on the organic thin film layer in a direction orthogonal to the plurality of positive electrode layers; And a power supply unit electrically connected to one side of the plurality of positive electrode layers, wherein the positive electrode layer is formed to have an increasing width as the distance from the power supply unit increases.

Organic electroluminescent element, luminance, voltage drop, resistance, positive electrode layer

Description

Organic electroluminescent element {ORGANIC ELECTRO LUMINESCENT DISPLAY DEVICE}

1 is a plan view schematically showing the configuration of a positive electrode layer in an organic EL device according to the prior art.

2 is a plan view schematically illustrating a configuration of a positive electrode layer in an organic EL device according to an exemplary embodiment of the present invention.

3 is a plan view schematically illustrating a configuration of a positive electrode layer in an organic electroluminescent device according to another exemplary embodiment of the present invention.

4 is a plan view schematically illustrating a structure of another positive electrode layer that may be applied to the organic EL device of the present invention.

   -Explanation of symbols for the main parts of the drawings-

100 transparent substrate 110 positive electrode layer

120: power supply unit

The present invention relates to an organic electroluminescent device capable of solving the non-uniformity of the luminance due to the voltage drop phenomenon of the positive electrode layer and maximizing the thermal and electrical stabilization and particle removal effect of the device by the aging process.

In general, the organic electroluminescent device is one of the flat panel display devices, and is formed between the positive electrode layer and the negative electrode layer on the transparent substrate through an organic thin film layer including an organic light emitting layer, and forms a very thin matrix.

Such an organic EL device can be driven at a low voltage of 15V or less, and exhibits excellent characteristics in brightness, viewing angle, power consumption, and the like, compared to other display devices, for example, TFT-LCD. In addition, the organic electroluminescent device has a fast response speed of 1 kHz compared to other display devices, and thus is suitable for a next-generation multimedia display in which moving picture is essential.

However, in the organic EL device according to the related art, a voltage drop phenomenon occurs due to an increase in resistance of the positive electrode layer as the power is applied, that is, away from the power applying unit, resulting in uneven luminance between pixels. In addition, there is a problem in that the effect of the aging process that proceeds for thermal and electrical stabilization of the device and particle removal on the positive electrode layer can not be properly achieved.

Hereinafter, the problems of the related art will be described in detail with reference to the accompanying drawings.

1 is a plan view schematically showing the configuration of a positive electrode layer in an organic EL device according to the prior art.

As shown in FIG. 1, in the organic EL device according to the related art, a plurality of positive electrode layers 110 including indium tin oxide (ITO), indium-doped zinc oxide or IXO (IZO), or the like may be used as the transparent substrate 100. It is arranged in a stripe shape on), the plurality of positive electrode layer 110 is electrically connected to the power supply unit 120 on one side.

In addition, on the openings of the plurality of positive electrode layers 110 defining each pixel, an organic light emitting layer which transmits holes from the positive electrode layer 110 and electrons from the negative electrode layer to emit light by itself, and the organic light emitting layer from the positive electrode layer. An organic thin film layer including a hole injection layer and a hole transport layer to assist hole transfer to the organic light emitting layer, and an electron injection layer and an electron transport layer to assist electron transfer from the negative electrode layer to the organic light emitting layer are formed.

On the organic thin film layer, a plurality of negative electrode layers arranged in a stripe shape along a direction orthogonal to the plurality of positive electrodes is formed.

That is, in the organic electroluminescent device, when power is applied to the positive electrode layer 110 and the negative electrode layer by the power applying unit 120, holes are formed from the positive electrode layer 110 in contact with the organic thin film layer in the opening of each pixel. It moves to the organic light emitting layer in this organic thin film layer, and similarly, an electron moves to the organic light emitting layer in an organic thin film layer from a negative electrode layer. These holes and electrons meet with each other in the organic light emitting layer to form electron-hole pairs and generate high energy excitons. It is to generate light. In addition, light generated from the organic light emitting layer through the above process is emitted through the lower transparent substrate 100, and thus, each pixel of the organic EL device emits light.

By the way, in the organic EL device according to the related art, as shown in FIG. 1, the positive electrode layers 110 arranged in a stripe shape on the transparent substrate 100 have a direction in which power is applied, that is, Since it is formed in a long rectangular shape having the same width irrespective of the distance from the power applying unit 120, when the power is applied from one side of the positive electrode layer 110, the distance from the power applying unit 120 is far As the resistance increases, the resistance of the positive electrode layer 110 increases, and thus, a voltage drop phenomenon of the positive electrode layer 110 occurs.

That is, even in one of the positive electrode layers 110 of the plurality of positive electrode layers 110, a relatively high voltage is applied to the positive electrode layer 110 in a pixel close to the power supply unit 120, whereas the pixel is far away from the positive electrode layer 110. Since a relatively low voltage is applied due to the voltage drop phenomenon, in the organic electroluminescent device according to the prior art, there arises a problem that luminance is uneven between pixels.

On the other hand, prior to completing the manufacturing process of the organic electroluminescent device and using it conventionally, aging for the organic electroluminescent device for the purpose of improving the thermal and electrical stability of the final device and to remove various particles on the positive electrode layer The process is in progress.

In this aging process, the organic electroluminescent device is operated by applying a high voltage to the positive electrode layer 110 and applying a predetermined voltage to the negative electrode layer according to the driving conditions of the organic electroluminescent device, and the device is left for a predetermined time during the operation of the device. In order to stabilize the operation of the device proceeds. In particular, in order to drive the organic electroluminescent device in such an aging process, a relatively high voltage must be applied to the positive electrode layer 110 for hole movement from the positive electrode layer 110.

However, in the organic EL device according to the related art, since a voltage drop phenomenon occurs according to the distance from the power supply unit 120 within one positive electrode layer 110, the positive electrode layer 110 in the aging process as described above. There was a problem in that high and uniform voltage could not be properly applied to all the areas. For this reason, according to the prior art, the effect of thermal and electrical stabilization and particle removal of the organic electroluminescent element in the aging step cannot be achieved properly.

Due to this problem of the prior art, it is possible to solve the voltage drop phenomenon of the positive electrode layer 110, to solve the nonuniformity of brightness, and to maximize the thermal and electrical stabilization of the device by the aging process and the effect of removing particles on the positive electrode layer. There is an urgent need for a structure of an organic electroluminescent device.

Accordingly, the present invention can solve the non-uniformity of the luminance due to the voltage drop phenomenon of the positive electrode layer, and at the same time maximize the thermal and electrical stabilization of the device by the aging process and particle removal effect To provide an organic electroluminescent device that can be.

In order to achieve the above object, the present invention provides a plurality of positive electrode layers arranged in a stripe shape on a transparent substrate; An organic thin film layer formed on the plurality of positive electrode layers; A plurality of negative electrode layers arranged in a stripe shape on the organic thin film layer in a direction orthogonal to the plurality of positive electrode layers; And a power supply unit electrically connected to one side of the plurality of positive electrode layers, wherein the positive electrode layer is formed to have an increasing width as the distance from the power supply unit increases. Provided is a light emitting device.

That is, according to the organic electroluminescent device of the present invention, since the positive electrode layer is formed to have a wider width as the distance from the power applying unit becomes farther, such a positive electrode layer is almost constant regardless of the distance from the power applying unit. You have resistance. Accordingly, since the voltage drop phenomenon of the positive electrode layer does not occur according to the distance from the power applying unit, the luminance of each pixel formed on the positive electrode layer may be uneven. In addition, in the aging process, a high and uniform voltage may be applied to all regions of the positive electrode layer irrespective of the distance from the power applying unit, thereby maximizing the thermal and electrical stabilization and particle removal effects of the device according to the aging process. .

In the organic electroluminescent device according to the present invention, the power applying unit is formed on one side of the transparent substrate to be electrically connected to one side of all of the plurality of positive electrode layers in one direction of the transparent substrate to apply power. Two may be formed on both sides of the transparent substrate, and one of the power applying units is electrically connected to one side of some of the plurality of positive electrode layers in one direction of the transparent substrate to apply power, and the other one of the power sources. The applying unit may be electrically connected to the opposite side of the remaining positive electrode layer in the opposite direction of the transparent substrate to apply power.

In the former case, since all of the plurality of positive electrode layers are connected to a single power supply unit at one side, all of them are formed to have an increasing width in one direction. In the latter case, some of the plurality of positive electrode layers Since one side is connected to one power supply unit while the other is connected to the other power supply unit on the opposite side with respect to the transparent substrate, the part of the positive electrode layer and the remaining positive electrode layer is increased in the opposite direction to each other It is formed to have a width. Here, as the organic electroluminescent device becomes higher resolution and larger in area, a higher voltage must be applied to the plurality of positive electrode layers, and the number of positive electrode layers also increases significantly, so that the latter two power supply units divide and apply power to the positive electrode layers. Is more preferred.

In addition, in the organic electroluminescent device according to the present invention, the positive electrode layer may be formed to have a continuously increasing width as the distance from the power supply unit is far away, on the contrary, from the power supply unit It may be formed to have a width that increases by a predetermined value at regular intervals away from each other.

In the former case, the positive electrode layer has a long trapezoidal shape in plan view, and in the latter case, a plurality of rectangles having an increasing width are connected to each other. The latter case is more preferred in view of the ease and ease of mask fabrication for patterning.

Hereinafter, a structure of an organic electroluminescent device according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings so that a person skilled in the art may easily implement the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In addition, the same reference numerals are attached to similar parts throughout the present specification.

2 is a plan view schematically illustrating a configuration of a positive electrode layer in an organic EL device according to an exemplary embodiment of the present invention.

Referring to FIG. 2, in the organic electroluminescent device according to an embodiment of the present invention, a plurality of positive electrode layers 110 including indium tin oxide (ITO), indium-doped zinc oxide or IXO (IZO), and the like are transparent. It is arranged in a stripe shape on the transparent substrate 100 made of glass or plastic, and the plurality of positive electrode layers 110 are electrically connected to the power applying unit 120 at one side.

However, in the present embodiment, as shown in FIG. 2, the plurality of positive electrode layers 110 have a width that increases gradually as the distance from the power applying unit 120 increases in the direction in which power is applied. In particular, the distance from the power supply unit 120 is formed to have a continuously increasing width to form a trapezoidal shape in plan view.

That is, even if the distance from the power supply unit 120 is far along the direction in which the one positive electrode layer 110 is connected, the width of the positive electrode layer 110 is widened by the distance from the power supply unit 120. Irrespective of the distance, almost all resistance regions of the positive electrode layer 110 have a constant resistance value. For this reason, in this embodiment, since the voltage drop phenomenon of the positive electrode layer 110 according to the distance from the power supply unit 120 does not occur, the luminance of each pixel formed on the positive electrode layer 110 becomes uneven. Can be solved. In addition, in the aging process, since a high and uniform voltage can be applied to all regions of each positive electrode layer 110 regardless of the distance from the power supply unit 120, thermal and electrical stabilization of particles and particles according to the aging process The elimination effect can be maximized.

On the other hand, a lattice-shaped insulating film made of an insulating material such as a photoresist film is formed on the positive electrode layer 110 and the transparent substrate 100, whereby openings of each pixel are defined on the positive electrode layer 110, and the positive electrode On the insulating layer orthogonal to the layer 110, a partition wall formed of a photosensitive film or the like for patterning the organic thin film layer and the negative electrode layer is formed.

The organic thin film layer 120 is formed on the positive electrode layer 110 exposed by the opening of each pixel. The organic thin film layer 120 may include an organic light emitting layer that transmits holes from the positive electrode layer 110 and electrons from the negative electrode layer and emits light by itself, a hole injection layer that assists hole transfer from the positive electrode layer to the organic light emitting layer, and And a hole transport layer, and an electron injection layer, an electron transport layer, and the like, which assist electron transfer from the negative electrode layer to the organic light emitting layer.

Herein, the hole injection layer, the hole transport layer, the organic light emitting layer, the electron transport layer, and the electron injection layer may be formed using all materials conventionally used in various organic electroluminescent devices, and the type of each material and each organic thin film layer. The method of forming is apparent to those skilled in the art.

In addition, a plurality of negative electrode layers arranged in a stripe shape in a direction orthogonal to the plurality of positive electrode layers 110 are formed on the organic thin film layer, and the plurality of negative electrode layers are electrically connected to the power applying unit 120 at one side. It is connected so that power is applied therefrom.

The negative electrode layer may be made of any one metal material selected from the group consisting of aluminum, copper, gold, silver, and alloys thereof. All of these metal materials exhibit low resistance and excellent electrical conductivity, and thus can be preferably used as the negative electrode layer in the organic electroluminescent device according to the present embodiment.

On the other hand, in the configuration of the organic EL device according to the present embodiment as described above, the remaining configuration except the configuration of the positive electrode layer 110, that is, the configuration of the organic thin film layer, insulating film, barrier rib and negative electrode layer, etc. Since a conventional configuration of the same organic electroluminescent device is used, detailed description thereof will be omitted.

In the organic electroluminescent device according to the present embodiment having such a configuration, as in the prior art, when power is applied to the positive electrode layer 110 and the negative electrode layer by the power applying unit 120, organic light is emitted from the opening of each pixel. Holes move from the positive electrode layer 110 in contact with the thin film layer to the organic light emitting layer in the organic thin film layer, and similarly, electrons move from the negative electrode layer to the organic light emitting layer in the organic thin film layer. These holes and electrons meet with each other in the organic light emitting layer to form electron-hole pairs and generate high energy excitons. To generate light. In addition, light generated from the organic light emitting layer through the above process is emitted through the lower transparent substrate 100, and thus, each pixel of the organic EL device according to the present embodiment emits light.

That is, in the organic electroluminescent device according to the present embodiment, each pixel emits light by the same principle and process as in the prior art. However, in the prior art, in the light emitting process of each pixel, the resistance of the positive electrode layer 110 increases as the distance from the power supply unit 120 increases, and thus, the direction of each positive electrode layer 110 is changed. As a result, a voltage drop occurs in a pixel far from the power applying unit 120, resulting in a non-uniform luminance with a pixel near the power applying unit 120. As the distance from the part 120 increases, the positive electrode layer 110 has an increasing width, and thus such voltage drop hardly occurs.

Therefore, in the organic electroluminescent device according to the present embodiment, there is no problem of uneven brightness between the pixels, and furthermore, even in the aging process of the organic electroluminescent device, it is uniform and high in all regions of the positive electrode layer 110. By applying a voltage, it is possible to maximize the thermal and electrical stabilization of the device by the aging process and the particle removal effect on the positive electrode layer.

On the other hand, Figure 3 is a plan view schematically showing the configuration of the positive electrode layer in an organic electroluminescent device according to another embodiment of the present invention.

In one embodiment of the present invention described above, the power applying unit 120 for applying power to the positive electrode layer 110 is formed on one side of the transparent substrate 100, the plurality of in one direction of the transparent substrate Although it is configured to apply power by being electrically connected to one side of both electrode layers of the power supply, two power supply units 120 are formed on both sides of the transparent substrate 100 so that one of the power is applied. The unit 120 is electrically connected to one side of some of the plurality of positive electrode layers 110 in one direction of the transparent substrate 100, thereby applying power to some of the positive electrode layers 110, and applying the other power. The unit 120 may be electrically connected to the opposite side of the remaining positive electrode layer 110 in the opposite direction of the transparent substrate 100 to apply power to the remaining positive electrode layer 110. An organic electroluminescent device according to another embodiment of the present invention having such a configuration is as shown in FIG. 3.

That is, as shown in Figure 3, in the organic electroluminescent device according to another embodiment of the present invention, as the power applying unit 120 is divided into two formed on both sides of the transparent substrate 100, the plurality of Some of the positive electrode layer 110 is connected to one power supply unit 120 at one side, while the other positive electrode layer 110 is the remaining power on the opposite side based on the transparent substrate 100. Since it is connected to the applying unit 120, the part of the positive electrode layer 110 and the remaining positive electrode layer 110 is formed to have an increasing width in the opposite direction to each other.

According to the configuration of the organic electroluminescent device, each positive electrode layer 110 has a width gradually increasing as the distance from the power supply unit 120 increases, the effect according to the present invention can be achieved as it is.

In addition, in the configuration of the organic EL device according to another embodiment of the present invention, since the two power supply unit divides the power supply to the plurality of positive electrode layer, compared to the case of using a single power supply unit, more positive electrode layer Since a high voltage can be applied efficiently and uniformly, it can be advantageously used in high resolution, large area organic electroluminescent devices.

On the other hand, in the organic electroluminescent device according to another embodiment of the present invention, the rest of the configuration except for the power supply unit 120 and the positive electrode layer 110 is the same as the organic electroluminescent device according to an embodiment of the present invention Therefore, further description will be omitted.

4 is a plan view schematically illustrating a structure of another positive electrode layer that may be applied to the organic EL device of the present invention.

That is, in both embodiments of the present invention described above, the positive electrode layer 110 is formed to have a continuously increasing width as the distance from the power supply unit 120 increases, so that the shape of the trapezoid in plan view. Alternatively, the positive electrode layer 110 having a width that increases by a predetermined value at regular intervals may be applied to the present invention. As shown in FIG. 4, the positive electrode layer 110 has a shape in which a plurality of rectangles having an increasing width are connected to each other.

The other positive electrode layer 110 applicable to the present invention also has a width that increases as the distance from the power supply unit 120 increases, and thus may have all the effects and effects of the present invention. In addition, when the positive electrode layer 110 is formed to have a width that increases by a predetermined value at regular intervals, compared to the case of the positive electrode layer 110 having a trapezoidal shape having a continuously increasing width, The process of patterning the positive electrode layer 110 becomes smoother, and there is an advantage in that it is easier to manufacture an exposure mask used in such a patterning process.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, according to the present invention, it is possible to prevent the problem of uneven brightness between the pixels of the organic electroluminescent device, and furthermore, to effect the thermal and electrical stabilization of the device by the aging process and the particle removal effect on the positive electrode layer. It can be maximized.

Therefore, the quality and reliability of the organic electroluminescent device can be greatly improved, and the lifetime can also be greatly increased.

Claims (5)

A plurality of positive electrode layers arranged in a stripe shape on the transparent substrate; An organic thin film layer formed on the plurality of positive electrode layers; A plurality of negative electrode layers arranged in a stripe shape on the organic thin film layer in a direction orthogonal to the plurality of positive electrode layers; And An organic electroluminescent device comprising a power supply unit electrically connected to one side of the plurality of positive electrode layers, The positive electrode layer is an organic electroluminescent device, characterized in that formed with a width that increases as the distance from the power supply. The method of claim 1, wherein the power applying unit is formed on one side of the transparent substrate, An organic electroluminescent device for applying power by being electrically connected to one side of all of the plurality of positive electrode layers in one direction of the transparent substrate. The method of claim 1, wherein two power supply units are formed on both sides of the transparent substrate, One of the power applying units is electrically connected to one side of some of the plurality of positive electrode layers in one direction of the transparent substrate to apply power. An organic electroluminescent device for applying power by being electrically connected to the other side of the other positive electrode layer in a direction opposite to the transparent substrate. The organic electroluminescent device according to any one of claims 1 to 3, wherein the positive electrode layer is formed to have a width that continuously increases as the distance from the power supply unit increases. The organic electroluminescent device according to any one of claims 1 to 3, wherein the positive electrode layer widens stepwise at a predetermined distance in a direction away from the power applying unit.

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