KR100844783B1 - Organic Light emitting display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display device, in which a cathode electrode connected to a scan line in a pixel array having an organic light emitting element as a unit pixel is gradually increased from the side to which the scan line is connected, thereby increasing the width of the electrode. It is characterized by reducing the sheet resistance.

Organic light emitting display, voltage drop, sheet resistance, cathode

Description

Organic light emitting display device

1 is a plan view of a conventional organic light emitting display device.

2A is a plan view of an organic light emitting display device according to an embodiment of the present invention.

FIG. 2B is a cross sectional view along line BB ′ of FIG. 2A;

3A to 3F are cross-sectional views illustrating a manufacturing process of an organic light emitting display device according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

101 substrate 110 anode electrode

120: organic light emitting layer 130: cathode electrode

140: scan line 150: data line

170: insulating layer 180: partition wall

In the organic light emitting display, when the organic light emitting layer is positioned between the electrodes facing each other, and a voltage is applied between both electrodes, electrons injected from one electrode and holes injected from the other electrode are combined in the organic light emitting layer. It is one of the flat panel display devices using the organic light emitting device that emits the energy emitted by the light emitting molecules of the light emitting layer once coupled to return to the ground state by coupling.

An organic light emitting display device having such a light emission principle is attracting attention as a next-generation display because of its excellent visibility, weight reduction, thin film thickness, and low voltage operation.

First, FIG. 1 is a plan view of an organic light emitting display device according to the prior art. Accordingly, the organic light emitting diode formed on the panel of the organic light emitting display device includes an anode electrode 10, an organic light emitting layer 20, and a cathode electrode 30 formed on a substrate.

A plurality of anode electrodes 10 are vertically arranged on the substrate at predetermined intervals, and are electrically connected to the driving integrated circuit through data lines.

The organic light emitting layer 20 is formed on the anode electrode 10, in which the organic light emitting layer is meant to include various organic thin films interposed between the anode electrode 10 and the cathode electrode 30.

An end of the cathode electrode 30 is connected to the scan line 40, is formed on the organic light emitting layer 20, and is formed to cross the anode electrode 10. As a result, the organic light emitting layer 20 is positioned at the point where the anode electrode 10 and the cathode electrode 30 cross each other.

Meanwhile, according to the pixel formation method, a partition wall 60 (cathode separator) for forming the cathode electrode 30 may be provided. The partition wall 60 is formed perpendicular to the anode electrode 10 and the cathode electrode 30 is formed. ) Are spaced apart at predetermined intervals which may be located therebetween.

However, as the size of the organic light emitting display device increases, a voltage drop occurs as the sheet resistance of the electrode increases toward the opposite side from the side where the cathode electrode 30 is connected in the scan line 40. Therefore, the pixel P2 on the side of the peninsula on which the scan line 40 is connected to the cathode electrode emits light darker than the pixel P1 on the opposite side, resulting in a deterioration in image quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic light emitting display device in which all pixels have uniform luminance without increasing the length of the display panel and increasing the length of the electrode to cause voltage drop.

In one embodiment, an organic light emitting display device including a pixel array including an organic light emitting diode, wherein the pixel array is disposed on the substrate, extends in a Y direction, and is connected to a first signal line. A first electrode; An organic light emitting layer formed in the pixel area on the first electrode; And a plurality of second electrodes intersecting with the first electrode and extending in the X direction with the organic light emitting layer interposed therebetween, the both ends being alternately connected to both ends of the second signal line. Formed at the intersection of the second electrode and the second electrode, and in the pixel array, the length of the Y direction of the first pixels on the side of which the second signal line is connected to the second electrode is L1, and the X direction of the first pixels The length of the second pixel at the opposite point is L2, and L1 is smaller than L2.

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

FIG. 2A is a plan view of an organic light emitting display device according to an exemplary embodiment of the present invention, FIG. 2B is a cross-sectional view taken along the line BB ′ of FIG. 2A, and FIG. 3B is a cross-sectional view taken along the line AA ′ of FIG. 2A. . Accordingly, the plurality of organic light emitting diodes included in the pixel array formed on the substrate of the organic light emitting diode display includes an anode electrode 110, an organic light emitting layer 120, and a cathode electrode 130.

A plurality of anode electrodes 110 are vertically arranged at predetermined intervals on the substrate, and are electrically connected to a driving integrated circuit (not shown) through the data line 150. In this case, the anode electrode 110 may be made of indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO 2), or zinc oxide (ZnO).

The organic light emitting layer 120 is formed on the anode electrode 110. In this embodiment, the organic light emitting layer 120 is meant to include various organic thin films interposed between the anode electrode 110 and the cathode electrode 130. That is, the light emitting layer may optionally include an electron injection layer, an electron transport layer, a hole injection layer, a hole transport layer, and the like.

One end of the cathode electrode 130 is connected to the scan line 140 and formed to intersect the anode electrode 110 on the organic light emitting layer 120. As a result, the organic light emitting layer 120 is positioned at the intersection of the anode electrode 110 and the cathode electrode 130. As the cathode electrode 130, lithium, magnesium, aluminum, aluminum lithium, calcium, magnesium indium, magnesium silver, or the like may be used.

Each of the organic light emitting diodes constitutes one pixel in the organic light emitting display, and may emit red, green, and blue light depending on the material of the light emitting layer. The unit pixel includes an insulating layer 170 to electrically insulate between the pixels, whereby the pixels are substantially partitioned. That is, since the insulating layer 170 forms an edge of each unit pixel, the shape of each pixel coincides with the unit lattice shape of the insulating layer.

In the present embodiment, the unit pixel shape defined by the insulating layer has a length in the X direction equal to the length in the X direction of adjacent pixels in the same row, but a length in the Y direction is different from adjacent pixels in the same row. At this time, in the present embodiment, for convenience of description, the direction in which the anode electrode 110 extends is set to the X direction, and the direction in which the cathode electrode 130 extends is set to the Y direction.

For example, the length of each pixel in the Y-direction gradually increases from the pixel P1 on the side connected to the N-th row cathode electrode 130 to which the N-row scan line 140 is connected, to the pixel P2 on the opposite side. Longer That is, when the length of the Y-direction of the pixel P1 on the side where the scan line 140 is connected to the cathode electrode 130 is L1, the length of the Y-direction of the opposite point pixel P2 is L2 (L2> L1). The length in the Y direction of the pixels therebetween gradually increases from L1 to L2.

In this case, when the scan line 140 is connected at the right end of the cathode electrode 130 in the N row of the pixel, the scan line 140 is connected at the left end in the N + 1 row. In the N + 1 row, the pixel on the side connected to the cathode electrode has a length L2 in the Y direction, and the length in the Y direction of the opposite pixel is L1. As a result, the length of the cathode electrode 130 is such that the lengths of the Y-directions are complementary to each other, so that the length of the Y-directions of the entire panel is not changed.

Accordingly, components of the organic light emitting diodes formed in each unit pixel, that is, each of the anode electrode 110, the organic light emitting layer 120, and the cathode electrode 130 may also change according to the size of each pixel.

Meanwhile, according to a method of manufacturing a pixel, which will be described later, a partition wall 180 (cathode separator) for forming a cathode electrode may be provided. In this embodiment, a gap between the partition wall 180 formed around the pixel portion according to the size change of the pixel is provided. It will also be different.

That is, the distance between the partition walls 180 defining the width of the cathode electrode 130 is formed to be the same as the length of the above-described Y direction of the pixel, so that the distance between each vertical partition wall of each row pixel is gradually reduced from L1 to L2, or , From L2 to L1.

Hereinafter, an embodiment of the method of manufacturing the organic light emitting display device described above will be described with reference to FIGS. 3A to 3E.

First, it is a step of providing a substrate 101 (Fig. 3a).

Next, the anode electrode 110 is formed. That is, the anode electrode material is applied and patterned on the substrate. The anode electrode 110 is a plurality of electrodes are patterned at regular intervals. Although not shown, the normal scan line 140 and data line 150 are both patterned at this stage (FIG. 3B).

Next, the insulating layer 170 is insulated from each other. The insulating layer 170 is formed to substantially border each pixel with a predetermined thickness, and the length in one (X) direction of the unit grid (that is, the unit pixel forming region) of the insulating layer 170 is adjacent to the same row. The length in one direction of the pixel is the same, but the length in the other (Y) direction is different from that of adjacent pixels in the same row (Fig. 3C).

Next, the partition wall 180 is formed. The partition wall 180 is formed in a direction parallel to the cathode electrode 130 so that the cathode electrode 130 is formed in a stripe type. The partition wall 180 is formed in a structure having an inverted trapezoidal cross section on the insulating layer 170. The partition wall may be formed by photolithography. (FIG. 3D)

Next, the organic light emitting layer 120 is formed. The organic light emitting layer 120 is formed through deposition, and in the case of a color, a different material for each organic light emitting layer 120 will be used. In addition, as described above, since the organic light emitting layer 120 is meant to include various organic thin films interposed between the anode electrode 110 and the cathode electrode 130, a hole injection layer, a hole transport layer, an electron transport layer, An electron injection layer or the like may be further deposited before or after the deposition of the actual light emitting layer (FIG. 3E).

Next, the cathode electrode 130 is formed. When the cathode electrode material is applied to the entire surface by the inverted trapezoid-shaped partition wall 180 formed in the direction parallel to the cathode electrode 130, the cathode electrode material is not coated directly below the partition wall, so that the cathode electrode 130 is striped. You will be able to create (Figure 3f)

Although the present invention has been described primarily with reference to the above embodiments, many other possible modifications and variations can be made without departing from the spirit and scope of the invention. For example, in the above-described embodiment, the anode electrode and the cathode electrode are named for convenience of description, but even the general case of the first electrode and the second electrode has only been changed in the stacking order thereof, and thus those skilled in the art will be able to easily modify them. In addition, although each signal wiring is specifically indicated by a scan electrode and a data electrode, the order change thereof may be easily modified by those skilled in the art.

The organic light emitting display device according to the present invention has an effect of providing uniform luminance to all pixels by supplying a constant voltage without voltage drop in all sections in the panel. In this case, the overall opening ratio is not affected, and the present structure can be realized by a simple change of the photomask of the conventional insulating layer and the partition wall.

The scope of the above-described invention is defined in the following claims, and is not bound by the description in the text of the specification, all modifications and variations belonging to the equivalent scope of the claims will fall within the scope of the present invention.

Claims (8)

A plurality of first electrodes extending in the Y direction on the substrate and connected to the first signal line; An organic light emitting layer formed in the pixel area on the first electrode; And A plurality of second electrodes extending in the X direction with the organic light emitting layer interposed therebetween and connected to a second signal line; A plurality of pixels are formed at the intersection of the first electrode and the second electrode, An organic light emitting display device according to claim 1, wherein the lengths of the pixels adjacent to each other in the same row have the same length and the lengths of the Y directions are different. The method of claim 1, The length of the Y direction of the pixels adjacent to each other in the same row is gradually increased toward the opposite point in the X direction at the side connected to the second signal line. The method of claim 1, And the first electrode is an anode electrode and the second electrode is a cathode electrode. The method of claim 3, wherein And the anode electrode is one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO 2), and zinc oxide (ZnO). The method of claim 3, wherein And the cathode is one selected from the group consisting of lithium, magnesium, aluminum, aluminum-lithium, calcium, magnesium-indium, and magnesium-silver. The method of claim 1, And wherein the first signal line is a data line and the second signal line is a scan line. The method of claim 1, The length of the X direction and the length of the Y direction is defined by an insulating layer for insulating between the pixels. The method of claim 1, And a barrier rib formed in a direction parallel to the second electrode and dividing the pixels.

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