KR100638084B1 - Organic electro luminescence display device - Google Patents

Abstract

A plurality of data lines, a plurality of scan lines intersecting the data lines, an organic electroluminescent element disposed in an area formed by crossing the plurality of day lines and the scan line, and a pixel driving element for driving the organic electroluminescent element And the data line or / and the scan line electrically connected to the pixel driving element are formed so as to have a width different from that of other portions along the length direction of the portion electrically connected to the pixel driving element.

Organic, OLED, Data Line, Scan Line, Width, Contact Hole, Capacitor, Opening Ratio

Description

Organic electroluminescent display device {ORGANIC ELECTRO LUMINESCENCE DISPLAY DEVICE}

1 is a schematic diagram illustrating an organic light emitting display device according to an exemplary embodiment of the present invention.

FIG. 2 is a partial plan view illustrating a configuration corresponding to one pixel in the organic light emitting display according to the exemplary embodiment of the present invention.

FIG. 3 is an enlarged partial plan view of the main part of FIG. 2.

4 is a partial plan view illustrating a configuration corresponding to one pixel in a general organic electroluminescent display.

5 is a partial cross-sectional view illustrating a configuration corresponding to one pixel in a general organic light emitting display device.

FIG. 6 is a plan view illustrating a configuration corresponding to one pixel in a typical organic electroluminescent display.

The present invention relates to an organic light emitting display device, and more particularly, to a connection structure of a data line or a scan line and a transistor of an organic light emitting display device.

An organic electroluminescent display is commonly referred to as EL for convenience. A display device is a self-luminous display that electrically excites fluorescent and / or phosphorescent organic compounds to emit light, and can be driven at a low voltage. It is a display that can easily solve the drawbacks pointed out as a problem in the liquid crystal display device, such as a wide viewing angle, fast response speed, has attracted attention as a next-generation display, in particular, a display for mobile.

In the organic EL display device, an organic light emitting layer having a predetermined pattern is formed on glass or other transparent insulating substrate, and positive and negative electrode layers are formed on and under the organic light emitting layer to apply a driving voltage to the organic light emitting layer. The organic light emitting layer is formed of an organic compound.

In the organic EL display device having such a basic configuration, as the anode and cathode voltages are applied to the electrodes, holes injected from the electrode to which the anode voltage is applied are moved to the organic light emitting layer via the hole transport layer, and the electrons are The cathode is injected into the organic light emitting layer through the electron transport layer from the electrode. As a result, electrons and holes are recombined in the organic light emitting layer to generate excitons, and the organic material of the organic light emitting layer emits light as the excitons change from the excited state to the ground state, thereby realizing a desired image. Will be.

FIG. 5 shows a cross-sectional structure of an active matrix type organic EL display device of the conventional organic EL display device.

Referring to the drawing, in the organic EL display device, a buffer layer 105 is formed on an insulating substrate 100, and a thin film transistor and a capacitor are formed on the buffer layer 105. The thin film transistor may be formed on the semiconductor layer 110 including the source / drain regions 111 and 115, the gate electrode 125 formed on the gate insulating layer 120, and the interlayer insulating layer 130. And the source / drain electrodes 141 and 145 connected through the / drain regions 111 and 115 and the contact holes 131 and 135.

In addition, the capacitor is formed of the same material as the gate electrode 125, and formed on the gate insulating layer 120, and the source / drain electrode 141 formed on the interlayer insulating layer 130. , 145, for example, a second electrode 147 connected to the source electrode 141.

An insulating layer 150 is formed on the substrate 100 over the thin film transistor and the capacitor, and an anode electrode 160 electrically connected to the drain electrode 145 is formed on the insulating layer 150 on the pixel area. The anode electrode 160 may be made of indium tin oxide (ITO) and a transparent material, and the connection with the drain electrode 145 may expose the portion of the drain electrode 145 to expose the insulating layer 150. The anode electrode 160 is connected to the shape drain electrode 145 through the via hole 155 formed thereon.

An organic light emitting layer 180 is formed on the anode electrode 160, and a cathode electrode 190 made of a metal material such as aluminum (Al) is electrically connected to the organic light emitting layer 180. The planarization layer 170 is formed between the electrode 190, the anode electrode 160, and the insulation layer 150.

Such an organic EL display device generally includes two of the above-described thin film transistors for switching and driving. Among the switching transistors, as shown in FIG. 6, the data lines D1 and D2 intersected with each other. And adjacent to the scan lines S1 and S2 ??, which are electrically connected to the data lines D1.

That is, the switching transistor 20 connects the source electrode 20a to the data line D1, and at this time, a substantial contact between the source electrode 20a and the data line D1 is performed by the switching transistor 20. The contact hole 22 is formed at an overlapping portion between the source electrode 20a and the data line D1.

On the other hand, in the organic EL display device, the organic EL element 24 corresponding to one pixel is disposed in a spatial region formed by crossing the data line D1 and the scan line S1, and the organic EL element 24 is formed. The aperture ratio is determined in accordance with the region (), that is, the region of the organic light emitting layer.

Accordingly, in the organic EL display device, it is determined how wide the area of the organic EL element 24 is in the pixel area determined by the arrangement state of the data line D1 and the scan line S1 to determine the aperture ratio of the device. It becomes an important factor.

However, the conventional organic EL display device has a problem in that the area of the organic EL element 24 is limited to a predetermined pixel area in view of the above aperture ratio, and thus the aperture ratio cannot be maximized. have.

This problem is due to the connection structure between the data line D1 and the transistor 20. That is, in the conventional organic EL display device, the data line D1 includes the contact hole 22 forming portion that is connected to the source electrode 20a of the transistor 20, and the line width W is along the length direction. Since it is made constant, the organic EL element 24 in the pixel region has a limit to increase its size.

This phenomenon is similarly occurring on the scan line side when the transistor is connected to the scan line.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide an organic EL display device capable of improving the aperture ratio by improving the structure of data lines or scan lines.

In the organic EL display device according to the present invention,

A plurality of data lines, a plurality of scan lines intersecting the data lines, an organic electroluminescent element disposed in an area formed by crossing the plurality of day lines and the scan line, and a pixel driving element for driving the organic electroluminescent element Including,

The data line and / or the scan line electrically connected to the pixel driving element are formed so that the width of a portion electrically connected to the pixel driving element along the length direction is different from that of another portion.

That is, in the present invention, the data line and / or the scan line are formed by making the width of the portion connected to the pixel driving element wider than the other portion width.

Further, the data line and / or the scan line are formed by forming the widths of the other portions in the same size.

The pixel driving element may include at least two transistors and a capacitor electrically connected to the transistors.

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

1 is a diagram schematically showing an organic EL display device according to the present invention. As illustrated, the organic EL display device of the present invention includes an organic EL display panel 100, a data driver 200, and a scan driver 300.

The organic EL display panel 100 includes a plurality of data lines D1... Dm extending in the column direction, and a plurality of scan lines S1... Sn intersecting the data lines D1 .. Dm and extending in the row direction. ) And an organic EL element 40 disposed in a pixel region formed by crossing the data lines D1... Dm and the scan lines S1 .. Sn and a pixel driving element for driving the organic EL element 40. 50).

In the above, the organic EL element 40 includes an organic EL layer and an anode electrode and a cathode electrode disposed with the organic EL layer interposed therebetween, and the pixel driving element 50 includes at least two transistors 52, 54, and a capacitor 56 electrically connected to the transistor. In this embodiment, the transistors 52 and 54 control the current flowing to the organic EL element 40 according to the voltage applied to the gate. And a switching transistor 52 which transfers the image signal applied to the data line in response to the selection signal to the driving transistor 52.

2 is a diagram for explaining a configuration corresponding to one pixel in the organic EL display device according to the present embodiment.

As illustrated, the switching transistor 52 is disposed close to the data lines D1... Dm and the scan lines S1 .. Sn, and electrically connects the source region to the data lines D1 through the contact hole 60. The drain region is electrically connected to the gate electrode of the driving transistor 54 and the contact hole 62 disposed at a position different from that of the switching transistor 52.

In contrast, the driving transistor 54 electrically connects its drain region to the power supply line Vdd arranged in parallel with the data line D1 through the contact hole 64. The region is electrically connected to the anode electrode of the organic EL element 40 via the contact hole 66 as well.

In addition, the capacitor 56 may be formed by the power supply line Vdd and the gate electrode of the driving transistor 54.

On the other hand, in the present invention, the data line D1 is formed by selectively varying its width along its longitudinal direction. That is, the data line D1 is formed by making the width w1 of the portion electrically connected to the switching transistor 52, that is, the width w1 of the portion where the contact hole 60 is formed, wider than the width w2 of the other portion. do. At this time, the width w2 of another site | part is made constant.

In the present invention, the data line D1 is formed to be variable in width along its length direction, except that the portion where the contact hole 60 is disposed is electrically connected to the switching transistor 52. This is to reduce the width of the organic EL element 40 disposed in the pixel region to further expand the width in a range that does not interfere with the connection.

That is, as shown in Fig. 3, the organic EL display device according to the present invention extends the area of the organic EL element 40 by the width portion of the data line D1 reduced in the pixel area ( It is possible to have an advantage in improving the aperture ratio according to the arrow direction of Figure 3).

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

For example, the present invention is not limited to varying the width of the data line to which the switching transistor of the pixel driving element is connected so that the area of the organic EL element is expanded, as shown in the above-described example, as shown in FIG. When the transistor 70 of the driving device is electrically connected to the scan line S, the contact hole 72 is configured to electrically connect the scan line S to the transistor 70 as in the above-described example. ) The width w3 of the forming portion is made larger than the width w4 of the other portion (this width is constant). As a result, the area of the organic EL element can be expanded, thereby improving the aperture ratio.

Of course, the present invention may extend the area of the organic EL element as in the above-described embodiments by varying the width of both the data line and the scan line electrically connected to the transistor along its length direction, in which case the aperture ratio The improvement will be maximized.

In addition, although the present embodiment has been described as being applied to an organic EL display device having two transistors, the present invention can also be applied to an organic EL display device having two or more transistors.

As described above, the organic EL display device according to the present invention improves the shape of the day line and the scan line connected to the transistor, thereby expanding the area of the organic EL display element disposed in the pixel area of the same size as before. As a result, the opening ratio may be improved to improve product quality.

Claims (8)

A plurality of data lines, a plurality of scan lines intersecting the data lines, an organic electroluminescent element disposed in an area formed by crossing the plurality of day lines and the scan line, and a pixel driving element for driving the organic electroluminescent element An organic electroluminescent display comprising: And the data line or the scan line electrically connected to the pixel driving element is formed by widening the width of a portion electrically connected to the pixel driving element along a length direction of the other portion than the width of the other portion. . delete The method of claim 1, The data line or the scan line is formed by forming the same width of the other portion of the organic light emitting display device. The method according to claim 1 or 3, The pixel driving device, And at least two transistors and capacitors electrically connected to the transistors. A plurality of data lines, a plurality of scan lines intersecting the data lines, an organic electroluminescent element disposed in an area formed by crossing the plurality of day lines and the scan line, and a pixel driving element for driving the organic electroluminescent element An organic electroluminescent display comprising: And the data line and the scan line electrically connected to the pixel driving element are formed by widening the width of a portion electrically connected to the pixel driving element in a length direction thereof than the width of the other portion. . delete The method of claim 5, wherein The data line and the scan line are formed by forming the same width of the other portion of the organic light emitting display device. The method according to claim 5 or 7, The pixel driving device, And at least two transistors and capacitors electrically connected to the transistors.

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