KR101603230B1 - Organic Light Emitting Display Device - Google Patents

Abstract

The present invention relates to an organic light emitting diode (OLED) display device capable of improving reliability and yield by eliminating a defect of a dark spot in an organic electroluminescent device. The organic light emitting diode display according to the present invention includes a plurality of gate lines, An aging line for supplying aging power to the plurality of red sub-pixels and the plurality of green sub-pixels, and a plurality of blue sub-pixels, And an aging line for blue which supplies aging power and is formed apart from the aging line.

OLED, P-aging, blue, dark spot, sub-pixel

Description

[0001] The present invention relates to an organic light emitting display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to an organic light emitting diode (OLED) display, and more particularly, to an organic light emitting diode (OLED) display capable of improving reliability and yield by eliminating a defective pixel defect in an organic light emitting diode.

The image display device that realizes various information on the screen is a core technology of the information communication age and it is becoming thinner, lighter, more portable and higher performance. In recent years, along with the development of an information society, various types of display apparatuses have been increasingly demanded, and various kinds of displays such as a liquid crystal display (LCD), a plasma display panel (PDP), an electro luminescent display (ELD) Research on devices is actively under way. Among them, an organic light emitting display device for displaying an image by controlling the amount of emitted light of an organic light emitting layer by a flat panel display device which can reduce weight and volume, which is a disadvantage of a cathode ray tube (CRT)

The OLED display is a self-luminous device using a thin light emitting layer between electrodes, and has an advantage that it can be thinned like a paper. The organic light emitting display device has a passive matrix type and an active matrix type according to a driving method, such as a top-emission type and a bottom-emission type, depending on a direction in which light is emitted. Matrix).

As shown in FIG. 1, the active matrix type organic light emitting display device (AMOLED) includes a plurality of organic light emitting display elements (OLEDs), each of which includes a plurality of unit pixels composed of three color (R, G, B) And a cell driver for independently driving the organic electroluminescent device.

The sub-pixels (PX) of the organic light emitting element is the intersection of the gate lines _{(GL 1, GL 2, ...} , GL n) and data lines _{(DL 1, DL 2, DL} 3, ..., DL m) Lt; / RTI > Here, three sub-pixels PX emitting different colors of red (R), green (G) and blue (B) form one unit pixel and the light emitting layer EL of the selected sub- And emits light according to the amount of current supplied from the cell driver to display an image. On the other hand, the lifetime of the B sub-pixel is shorter than that of the R and G sub-pixels, so that the aperture ratio of the B sub-pixel is designed to be large in order to compensate for this.

A P-aging process is performed in order to prevent defects of the organic EL device. In this case, each of the R, G, and B sub-pixels (not shown) The effect of the P-aging process is small because the voltage per unit area applied to the R sub-pixel or the B sub-pixel is smaller than that of the R sub-pixel or the G sub-pixel. As a result, as shown in FIG. 2, a large number of defective pixel points occur in sub-pixels or B-sub pixels than in G-sub pixels, thereby lowering the reliability of the OLED display.

It is an object of the present invention to provide an organic light emitting diode display capable of improving the reliability and yield by eliminating the defect of a dark spot in an organic electroluminescent device.

An OLED display according to an exemplary embodiment of the present invention includes a plurality of red sub-pixels, a plurality of green sub-pixels, and a plurality of blue sub-pixels, which are defined by vertical intersections of a plurality of gate lines and a plurality of data lines, An aging line for supplying aging power to a plurality of green sub-pixels, and a blue aging line for supplying aging power to the plurality of blue sub-pixels and spaced apart from the aging line.

 At this time, the emission region of one blue sub-pixel is wider than the emission region of one red sub-pixel and one green sub-pixel.

Here, the aging line supplies aging power only to the plurality of red sub-pixels and the plurality of green sub-pixels, and the blue aging line supplies the aging power to only the plurality of blue sub-pixels.

Each of the plurality of red sub-pixels, the plurality of green sub-pixels, and the plurality of blue sub-pixels includes a switching transistor responsive to a signal of the gate line, a driving transistor responsive to a signal of the data line, And an aging transistor responsive to a signal of a gate line.

The plurality of red sub-pixels further include a red organic electroluminescent device driven by the driving transistor to emit red light, and the plurality of green sub-pixels are driven by the driving transistor to emit green light The organic light emitting display further includes a green organic electroluminescent device, and the plurality of blue sub-pixels further include a blue organic electroluminescent device driven by the driving transistor to emit blue light.

The aging line is electrically connected to the plurality of red sub-pixels and the plurality of green sub-pixels to supply an aging power to the red organic electroluminescent device and the green organic electroluminescent device.

The blue aging line is electrically connected to the plurality of blue sub-pixels to supply the aging power to the blue organic electroluminescent device.

Wherein the aging transistor of the plurality of red sub-pixels and the plurality of green sub-pixels supplies power of the aging line to the red organic electroluminescent element and the green organic electroluminescent element in response to the sub-gate line, The aging transistor of the blue sub-pixel supplies the power source of the blue aging line to the blue organic electroluminescent element in response to the sub-gate line.

The aging transistor of the blue sub-pixel is driven independently of the aging transistor of the red sub-pixel and the green sub-pixel.

The organic light emitting display according to the present invention further includes a power supply line formed between the plurality of red sub-pixels, the plurality of green sub-pixels, and the plurality of blue sub-pixels to supply power to each sub-pixel.

Since the aging power for the blue sub-pixel can be separately applied to the blue sub-pixel in proportion to the size of the blue sub-pixel, it is possible to eliminate the defect of the dark point like the red and green sub- Reliability can be improved.

In addition, since the defect of each sub-pixel can be eliminated, the present invention can improve the yield of the OLED display.

Further, the present invention can improve the luminous efficiency and lifetime of the OLED display by forming blue sub-pixels wider than other sub-pixels.

Hereinafter, the organic light emitting diode display according to the present invention will be described in detail with reference to the accompanying drawings.

3, an organic light emitting display according to the present invention includes a plurality of gate lines GL1, GL2, ..., and GLn formed on a substrate (not shown) and a plurality of data lines DL1, DL2, DL3 , Green (G), and blue (B) sub-pixels PX defined by the vertical intersections of the red, green, and blue sub- A plurality of first power lines VDD1 and VDD2 for supplying a first power source and a second power line VSS for supplying a second power source are provided on a substrate (not shown) AL2, ... ALn and a plurality of blue aging lines BAL1, BAL2, ..., BALn are further formed.

Here, the red (R), green (G) and blue (B) subpixels PX are gathered to form one unit pixel UPX, and one subpixel PX is a non- Can be defined. A plurality of data lines DL1, DL2, DL3, ..., DLm, power source lines VDD1, VDD2, ..., and a plurality of gate lines GL1, GL2, ..., GLn, A cell driving part composed of aging lines AL1, AL2, ... ALn and a plurality of blue aging lines BAL1, BAL2, ..., BALn is formed and an organic electroluminescent device is formed in the light emitting area .

The first and second power lines VDD1 and VDD2 and the second power line VSS supply a first power and a second power to the respective subpixels PX so that the organic light emitting diode emits light. (R), green (G), and blue (B) sub-pixels PX of the pixel electrode PX. When a current path is generated between the first power supply lines VDD1, VDD2, ... and the second power supply line VSS, a driving current is supplied to the organic electroluminescent devices of the sub-pixels PX. Each of the first power supply lines VDD1, VDD2, ... is formed between the sub-pixels PX.

The plurality of aging lines AL1, AL2, ... ALn are connected to the red (R) subpixel PX and the green (G) subpixel PX and the red (R) And a green (G) sub-pixel PX, a first aging power for a P-aging (Poison aging) process. A plurality of aging lines AL1, AL2, ... ALn apply an electric field to red (R) and green (G) organic electroluminescent devices to apply a small amount of oxygen or moisture to the red (R) Of the electrodes constituting the organic electroluminescent device of FIG. A plurality of aging lines AL1, AL2, ... ALn are formed in parallel with the plurality of gate lines GL1, GL2, ..., GLn.

A plurality of blue aging lines BAL1, BAL2, ..., BALn are connected to the blue (B) sub-pixel PX and a P-aging (Poissonling) of the blue (B) And supplies a second aging power for the process. At this time, since the plurality of blue aging lines BAL1, BAL2, ..., BALn are separate lines separated from the plurality of aging lines AL1, AL2, ... ALn, It can be different from the power source. A plurality of aging lines for blue (BAL1, BAL2, ..., BALn) are formed by applying an electric field to a blue (B) organic electroluminescent element and injecting a small amount of oxygen or moisture to form an organic electroluminescent element of blue Shots of the electrodes are removed to compensate the dark spot.

A plurality of blue aging lines BAL1, BAL2, ..., BALn are spaced apart from a plurality of aging lines AL1, AL2, ..., ALn to form a plurality of gate lines GL1, GL2, ..., As shown in FIG.

On the other hand, the blue (B) sub-pixel has a shorter lifetime than the red (R) and green (G) sub-pixels and the aperture ratio of the blue (B) sub- Is designed to be larger.

4A to 4C, the configuration of each sub-pixel of red (R), green (G), and blue (B) will be described in more detail.

4A, the red (R) sub-pixel includes a switching transistor T1, a driving transistor T2, an aging transistor T3, a storage capacitor Cst, and a red (R) And includes a light emitting element OLED.

The switch transistor T1 is turned on to the scan signal of the gate line GL to supply the data signal from the data line DL to the driver transistor T2 while the driver transistor T2 is connected to the switch transistor T1 (OLED) between the first power supply line (VDD) and the second power supply line (VSS) in response to a data signal from the organic light emitting diode (OLED).

The aging transistor T3 is turned on to the signal of the sub gate line S-GL to supply the first aging power source of the aging line AL to the organic electroluminescence element OLED, (OLED). By aging, the electrodes constituting the organic electroluminescent device (OLED) are oxidized to prevent shorting of the electrodes by metallic foreign substances, thereby preventing the occurrence of the dark spot of the red (R) sub-pixel. The storage capacitor Cst serves to allow a constant current to flow through the driving transistor T2 even if the switching transistor is turned off.

In the drawing, only the switching transistor, the driving transistor and the aging transistor are shown as transistors constituting one sub-pixel (PX). However, the present invention is not limited thereto, and the sampling transistor or the aging transistor may be connected to the sampling transistor (Not shown) or a programming transistor (not shown). In addition, although two sub-pixels PX are shown to be formed with one data line DL therebetween, the present invention is not limited thereto.

The red (R) organic light emitting diode OLED, which is electrically connected to the driving transistor T2, emits red (R) light by emitting light in accordance with the current flow. The red (R) organic electroluminescent device OLED includes a first electrode (not shown), a second electrode (not shown) as a counter electrode, and an organic light emitting layer (not shown) . A first electrode (not shown) is electrically connected to the driving transistor T2 and a second electrode (not shown) includes a first electrode (not shown) with an organic light emitting layer (not shown) And is formed on the entire surface in a sub-pixel in a plate form on the substrate.

In this case, when the organic light emitting display device is designed as a back light, the first electrode is formed of a transparent conductive layer so that light emitted from the organic light emitting layer can be emitted toward the substrate, and the second electrode is formed of a metal layer. When the organic light emitting display is designed as a front emission type, the first electrode may be formed of a metal layer and the second electrode may be formed of a transparent conductive layer.

Here, the transparent conductive layer may be formed of indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO) Or a combination thereof. The metal layer may be formed of Cr, Al, AlNd, Mo, Cu, W, Au, Ni, Ag or the like, or an alloy or oxide thereof.

The organic light emitting layer (not shown) is a layer in which red (R) light is emitted when an exciton formed by the combination of holes and electrons injected from the first and second electrodes drops to a ground state. The organic light emitting layer (not shown) may include a hole injection layer, a hole transporting layer, an emission layer, an electron transporting layer, an electron injection layer ).

The hole injection, hole transporting layer, electron transporting layer, and electron injecting layer are common layers made of an organic insulating material, and the light emitting layer is a layer made of an organic material emitting light. Here, the light emitting layer includes an organic material that emits red (R) light.

Referring to FIG. 4B, the green (G) sub-pixel includes a switching transistor T1, a driving transistor T2, an aging transistor T3, a storage capacitor Cst, And includes a light emitting element OLED. The switching transistor T1, the driving transistor T2, the aging transistor T3, and the storage capacitor Cst of the green (G) sub-pixel have the same reference numerals and their functions and structures The organic electroluminescent device OLED of green (G) is excluded and a description thereof will be omitted.

The organic electroluminescent device OLED of green (G) emits green (G) light by emitting light according to the current flow. The organic electroluminescent device OLED of green (G) includes a first electrode (not shown), a second electrode (not shown) as a counter electrode, and an organic light emitting layer (not shown) .

The organic light emitting layer (not shown) is a layer in which green light is emitted as the exciton formed by the combination of holes and electrons injected from the first electrode and the second electrode drops to a ground state, , And a light emitting layer. The light emitting layer is made of an organic material that emits green (G) light.

Referring to FIG. 4C, the blue (B) sub-pixel includes a switching transistor T1, a driving transistor T2, an aging transistor T3, a storage capacitor Cst, And includes a light emitting element OLED. The switching transistor T1 of the blue (B) sub-pixel, the driving transistor T2 and the storage capacitor Cst are the same in function and structure as the same reference numerals shown in FIG. 4A, And the blue (B) organic electroluminescent device OLED are omitted, and a description thereof will be omitted.

The aging transistor T3 of the blue (B) sub-pixel is turned on by the signal of the sub-gate line S-GL to supply the second aging power of the blue aging line BAL to the organic electroluminescent element OLED Thereby aging the blue (B) organic electroluminescent device OLED. By aging, the electrodes constituting the organic electroluminescent device (OLED) are oxidized to prevent shorting of the electrodes by metallic foreign substances, thereby preventing the occurrence of the dark spot of the blue (B) sub-pixel.

 The blue (B) sub-pixel has a shorter lifetime than the red (R) and green (G) sub-pixels and is designed to have a large aperture ratio in order to compensate the red and green sub- (B) sub-pixel is smaller than the red (R) and green (G) sub-pixels, the aging effect may be small.

However, according to the present invention, in addition to the aging line (AL) electrically connected to the red (R) and green (G) sub-pixels, a blue aging line (BAL) , And a second aging power source different from the first aging power source through the blue aging line (BAL) to the blue (B) sub-pixel.

That is, since the second aging power source can be separately applied to the blue (B) sub-pixel in proportion to the size of the blue (B) sub-pixel by the blue aging line (BAL) Can be improved. As a result, it is possible to prevent the defect of a dark spot in the blue (B) sub-pixel at a similar ratio as in the red (R) and green (G) sub-pixels, thereby improving the reliability of the OLED display.

The organic electroluminescent device OLED of blue (B) emits blue (B) light by emitting light in accordance with the current flow. The blue (B) organic electroluminescent device OLED includes a first electrode (not shown), a second electrode (not shown) as a counter electrode, and an organic light emitting layer (not shown) do.

The organic light emitting layer (not shown) is a layer in which a blue (B) light is emitted as the exciton formed by the combination of holes and electrons injected from the first electrode and the second electrode drops to a ground state, , And a light emitting layer. The light emitting layer is made of an organic material emitting blue (B) light.

As described above, according to the present invention, the sub-pixels of blue (B) are formed to be wider than the sub-pixels of the other sub-pixels to improve the luminous efficiency and lifetime, It is possible to eliminate the defect in the pixel of the pixel, thereby preventing the disposal of the display panel and improving the yield of the OLED display.

The above-described techniques represent presently preferred embodiments, and the present invention is not limited to the above-described embodiments and the accompanying drawings. Modifications and other uses of the embodiments will be apparent to those skilled in the art, and such modifications and other uses are intended to be included within the spirit of the present invention or defined by the scope of the appended claims.

1 is a view showing an arrangement of sub-pixels of a conventional organic light emitting diode display.

2 is a graph showing a dark spot defect ratio of a sub pixel of a conventional organic light emitting display device.

3 is a view illustrating an arrangement of sub-pixels of an organic light emitting display according to the present invention.

4A to 4C are equivalent circuit diagrams of the sub-pixels shown in FIG.

Claims (10)

A plurality of red sub-pixels, a plurality of green sub-pixels and a plurality of blue sub-pixels, which are defined as vertical intersections of a plurality of gate lines and a plurality of data lines; An aging line for supplying aging power to the plurality of red sub-pixels and the plurality of green sub-pixels; And And an aging line for blue, which supplies aging power to the plurality of blue sub-pixels and is spaced apart from the aging line, The plurality of red sub-pixels, the plurality of green sub-pixels, and the plurality of blue sub- A switching transistor responsive to a signal of the gate line, A driving transistor responsive to a signal of the data line and And an aging transistor responsive to the signal of the sub-gate line. The OLED display of claim 1, wherein the emission region of one blue sub-pixel is wider than the emission region of one red sub-pixel and one green sub-pixel. The method of claim 1, wherein the aging line supplies aging power only to the plurality of red sub-pixels and the plurality of green sub-pixels, And the blue aging line supplies aging power only to the plurality of blue sub-pixels. delete The organic light emitting display according to claim 1, wherein the plurality of red sub-pixels further include a red organic electroluminescent device driven by the driving transistor to emit red light, Wherein the plurality of green sub-pixels further include a green organic electroluminescent device driven by the driving transistor to emit green light, Wherein the plurality of blue sub-pixels further include a blue organic electroluminescent device driven by the driving transistor to emit blue light. 6. The organic electroluminescent device according to claim 5, wherein the aging line is electrically connected to the plurality of red sub-pixels and the plurality of green sub-pixels to supply aging power to the red organic electroluminescent device and the green organic electroluminescent device To the organic light emitting display device. The OLED display of claim 5, wherein the blue aging line is electrically connected to the plurality of blue sub-pixels to supply aging power to the blue organic electroluminescent device. 6. The organic electroluminescent display device according to claim 5, wherein the aging transistors of the plurality of red sub-pixels and the plurality of green sub-pixels respond to the sub- Respectively, And the aging transistor of the plurality of blue sub-pixels supplies power of the blue aging line to the blue organic electroluminescent element in response to the sub-gate line. The organic light emitting diode display according to claim 1, wherein the transistor for aging the blue sub-pixel is driven independently of the transistor for aging the red sub-pixel and the green sub-pixel. The OLED display of claim 1, further comprising: a power supply line formed between the plurality of red sub-pixels, the plurality of green sub-pixels, and the plurality of blue sub-pixels to supply power to each sub-pixel.

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