KR102089338B1 - Organic Light Emitting Display - Google Patents

Abstract

The organic light emitting display device according to the present invention includes a light emitting unit made of an organic light emitting diode, a driving TFT (Thin Film Transistor) controlling a driving current flowing through the organic light emitting diode, and a gate-source voltage of the driving TFT according to a desired gradation. A pixel array in which a plurality of sub-pixels, each including a circuit portion including a plurality of switch TFTs for programming a; A gate driver supplying a scan pulse to a gate line connected to the circuit unit; And a data driver supplying a data voltage to a data line connected to the circuit unit; At least one sub-pixel among the sub-pixels includes at least two light emitting units and the circuit unit.

Description

Organic light emitting display device

The present invention relates to an active matrix type organic light emitting display device.

The active matrix type organic light emitting display device includes an organic light emitting diode (hereinafter referred to as “OLED”) that emits light by itself, and has a fast response speed, high light emission efficiency, high brightness, and a wide viewing angle.

The self-luminous device OLED includes an anode electrode and a cathode electrode, and an organic compound layer (HIL, HTL, EML, ETL, EIL) formed therebetween. The organic compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL) and an electron injection layer (Electron Injection layer, EIL). When a driving voltage is applied to the anode electrode and the cathode electrode, holes passing through the hole transport layer (HTL) and electrons passing through the electron transport layer (ETL) are moved to the emission layer (EML) to form excitons, and as a result, the emission layer (EML) Visible light is generated.

The organic light emitting display device arranges sub-pixels including OLEDs in a matrix form and adjusts the amount of light emitted by each OLED according to the gradation of video data. Each of the sub-pixels includes a circuit portion to drive the OLED, which is a light emitting portion. The circuit portion is provided with a driving TFT (Thin Film Transistor) that controls the driving current flowing through the OLED, and a plurality of switch TFTs for programming the gate-source voltage of the driving TFT according to a desired gradation.

The types of pixel defects in the organic light emitting display device are largely defective in the light emitting unit and defective in the circuit unit. The defect of the light emitting part is caused by a short circuit between the anode electrode and the cathode electrode due to various causes such as a foreign material during the process of forming the OLED. Defects in the circuit portion are caused by a larger number of TFTs formed on the panel and a more complicated process than other display elements.

In the organic light emitting display device, a sub-pixel in which a defect has occurred is recognized as a dark spot because normal light emission is impossible. However, since a sub-pixel of a specific color having a relatively high transmittance is higher than the sub-pixel of another color, visibility to this dark point is necessary. Thus, a dummy pixel structure is proposed as shown in FIG. 1.

In FIG. 1, “A” refers to dummy pixels, and “B” refers to normal pixels. While the normal pixel B is formed in the display area where the image is implemented, the dummy pixel A is formed in the non-display area outside the display area. The dummy pixel A is a pixel additionally formed for a repair process. In the dummy pixel structure, when a defect occurs in the circuit portion of the normal pixel B, the normal pixel B emits light by connecting the light emitting portion of the normal pixel B to the circuit portion of the dummy pixel A through a repair process. This eliminates defects in dark spots.

However, the repair process is complicated when a conventional dummy pixel structure is employed. Under the conventional dummy pixel structure, both the cutting process and the welding process should be included in the repair process. Then, two welding points, a repair line connecting them to each other, and a cutting point should be provided. Here, the cutting process means a process of disconnecting the defective circuit part from the light emitting part in the corresponding sub pixel, and the welding process means a process of connecting the light emitting part of the corresponding sub pixel to the circuit part of the corresponding dummy sub pixel.

Moreover, in the case of employing a conventional dummy pixel structure, it is possible to repair a defective circuit portion, but not to repair a defective light emitting portion.

Accordingly, an object of the present invention is to provide an organic light emitting display device that simplifies the repair process and repairs not only defective circuit parts but also defective light emitting parts.

In order to achieve the above object, an organic light emitting display device according to an exemplary embodiment of the present invention includes a light emitting unit formed of an organic light emitting diode, and a driving TFT (Thin Film Transistor) and a desired gradation to control a driving current flowing through the organic light emitting diode. A pixel array in which a plurality of sub-pixels are formed, each including a circuit portion including a plurality of switch TFTs for programming the gate-source voltage of the driving TFT accordingly; A gate driver supplying a scan pulse to a gate line connected to the circuit unit; And a data driver supplying a data voltage to a data line connected to the circuit unit; At least one sub-pixel among the sub-pixels includes at least two light emitting units and the circuit unit.

When a unit pixel is composed of a plurality of sub-pixels, the at least one sub-pixel is selected as a sub-pixel having a relatively high transmittance among sub-pixels in the unit pixel.

A plurality of circuits included in the same sub-pixel share one data line and operate simultaneously by the same scan pulse to receive the same data voltage from the shared data line.

Each of the plurality of light emitting parts included in the same sub pixel is connected to all circuit parts in the sub pixel.

At least one light-emitting unit or circuit unit among the plurality of light-emitting units and circuit units included in the same sub-pixel is selectively disconnected by a cutting process.

R sub-pixels, G sub-pixels, and B sub-pixels adjacent to each other in the sub-pixels constitute one unit pixel; The G sub-pixel includes a plurality of circuit parts electrically connected to each other and a plurality of light emitting parts.

R sub-pixels, W sub-pixels, G sub-pixels, and B sub-pixels adjacent to each other in the sub-pixels constitute one unit pixel; The W sub-pixel includes a plurality of circuit parts electrically connected to each other and a plurality of light emitting parts.

R sub-pixels, W sub-pixels, G sub-pixels, and B sub-pixels adjacent to each other in the sub-pixels constitute one unit pixel; The W sub-pixel and the G sub-pixel each include a plurality of circuit parts and a plurality of light-emitting parts electrically connected to each other.

The plurality of light emitting units and circuit units included in the same sub-pixel are electrically connected to each other through an "X" -shaped connection structure or a "H" -shaped connection structure.

According to the present invention, by forming at least two light emitting units and circuit units for a sub-pixel having a high transmittance among sub-pixels in a unit pixel, a welding process may be omitted during a repair operation, thereby simplifying the repair process. In addition, it is possible to easily repair not only a defective circuit portion but also a defective light emitting portion.

1 is a view showing a conventional repair method using a dummy pixel structure.
2 is a block diagram showing an organic light emitting display device according to the present invention.
3 is a circuit diagram showing an example of a sub-pixel formed in the organic light emitting display device of the present invention.
4A and 4B are diagrams showing examples of sub-pixels SP constituting one unit pixel.
5A and 5B, in the RWGB pixel structure in which a unit pixel is composed of four sub-pixels as shown in FIG. 4A, a plurality of light emitting units and circuit units are respectively formed for W (or W and G) sub-pixels having high transmittance. Drawing showing an example.
FIG. 6 is a view showing an example in which a plurality of light emitting units and circuit units are respectively formed for a G subpixel having high transmittance in an RGB pixel structure in which a unit pixel is composed of three subpixels as shown in FIG. 4B.
7A and 7B are views showing a connection structure between a plurality of light emitting units and circuit units included in the same sub-pixel.
8A and 8B are diagrams showing circuit structures of sub-pixels employing the connection structures of FIGS. 7A and 7B, respectively.
9 is a view showing a repair process for removing a defective portion through the cutting process.

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 2 to 9.

2 is a block diagram showing an organic light emitting display device according to the present invention. And, Figure 3 is a circuit diagram showing an example of a sub-pixel formed in the organic light emitting display device of the present invention.

Referring to FIG. 2, the organic light emitting diode display 10 according to the present invention provides a pixel array DA displaying an image through a plurality of sub-pixels SP and a plurality of signal lines 16. It includes a driver unit 15 for supplying a driving signal to the pixels (SP). The pixel array DA and the driver unit 15 are formed on the first substrate 11, and the pixel array DA is sealed by the second substrate 12.

In the pixel array DA, a plurality of data lines and a plurality of gate lines intersect, and sub-pixels SP are arranged in a matrix form for each intersection area.

The circuit configuration of the sub-pixels SP may be any known configuration. 3 shows one circuit configuration of the sub-pixel SP. The sub-pixel (SP) structure of FIG. 3 is the most simplified among various structures capable of compensating for variations in electrical characteristics (threshold voltage, electron mobility, etc.) of the driving TFT (DT). Hereinafter, the present invention will be described with an example in which the sub-pixel SP is configured as shown in FIG. 3, but it should be noted that the technical idea of the present invention is not limited to the circuit structure of FIG. 3.

The data lines may include a plurality of data voltage supply lines Dm and a plurality of reference lines Rm. In addition, the gate lines may include a plurality of first gate lines Gn1 and a plurality of second gate lines Gn2.

The sub-pixel SP is composed of a light emitting part and a circuit part. The light emitting unit is implemented with an OLED that emits light according to a driving current flowing between a high potential power (EVDD) and a low potential power (EVSS). The circuit unit is connected to the data line and the gate line, and operates according to driving signals supplied from the data line and the gate line. The circuit portion may include a driving TFT (DT) for controlling the driving current applied to the OLED, and a plurality of switch TFTs (ST1, ST2) for programming the gate-source voltage of the driving TFT (DT) according to a desired gradation. have. The circuit unit may further include a storage capacitor Cst maintaining the gate-source voltage of the programmed driving TFT DT. The first switch TFT ST1 is switched according to a first scan pulse supplied from the first gate line Gn1 to supply a data voltage to the gate electrode of the driving TFT DT. The second switch TFT ST2 is switched according to the second scan pulse supplied from the second gate line Gn2 to supply an initialization voltage to the source electrode of the driving TFT DT or the source electrode of the driving TFT DT The voltage applied to the reference line Rm may be charged as the sensing voltage Vref. Here, the sensing voltage Vref is a voltage that is the basis for determining a compensation value for compensating for the deviation in electrical characteristics of the driving TFT DT. The driver unit 15 may modulate digital video data based on the sensing voltage Vref to compensate for variations in electrical characteristics of the driving TFT DT.

The TFTs constituting the sub-pixel SP may be implemented in a p-type or n-type. Further, the semiconductor layer of the TFTs constituting the sub-pixel SP may include amorphous silicon or polysilicon or oxide.

The driver unit 15 includes a data driver for driving the data lines, a gate driving circuit for driving the gate lines, and a timing controller for controlling the operation of the data and gate drivers.

The data driver may convert digital video data to a data voltage under the control of a timing controller and then supply the data to the data voltage supply lines Dm. The data driver may supply the initialization voltage to the reference lines Rm under the control of the timing controller, and also sample the sensing voltage Vref charged in the reference lines Rm under the control of the timing controller.

The gate driver may generate the first and second scan pulses under the control of the timing controller and sequentially supply them to the gate lines. The gate driver may be directly formed on the first substrate 11 according to a gate-driver in panel (GIP) method.

The timing controller may control the operation timing of the data driver and the gate driver based on a plurality of timing signals, and modulate the input digital video data based on the sensing voltage Vref and supply it to the data driver.

4A and 4B show examples of sub-pixels SP constituting one unit pixel.

Referring to FIG. 4A, the unit pixel includes four sub-pixels, an R sub-pixel (SPR) for displaying red light, a W sub-pixel (SPW) for displaying white light, and a G sub-pixel (SPG) for displaying green light, and It may be composed of a B sub-pixel (SPB) for displaying blue light.

In this case, the R sub-pixel SPR is composed of the R light emitting part RE and the R circuit part RC, and the W sub-pixel SPW is comprised of the W light-emitting part WE and the W circuit part WC, and the G sub-pixel ( The SPG) is composed of the G light emitting unit GE and the G circuit unit GC, and the B sub-pixel SPB is comprised of the B light emitting unit BE and the B circuit unit BC.

Referring to FIG. 4B, the unit pixel is composed of three sub-pixels: an R sub-pixel (SPR) for displaying red light, a G sub-pixel (SPG) for displaying green light, and a B sub-pixel (SPB) for displaying blue light. Can be configured.

In this case, the R sub-pixel SPR is composed of the R light emitting part RE and the R circuit part RC, and the W sub-pixel SPW is comprised of the W light-emitting part WE and the W circuit part WC, and the G sub-pixel ( The SPG) is composed of the G light emitting unit GE and the G circuit unit GC, and the B sub-pixel SPB is comprised of the B light emitting unit BE and the B circuit unit BC.

Here, the present invention forms at least two light emitting units and circuit units for sub-pixels of a specific color having high transmittance among sub-pixels in a unit pixel. The transmittance of W subpixel is the highest, then the G subpixel is high, and the R and B subpixels have a relatively low transmittance. Sub-pixels with low transmittance are not well-recognized even when darkened in the repair process, and thus are not a significant problem. However, since a sub-pixel with high transmittance is easily recognized when darkened, the present invention forms a plurality of light-emitting units and circuit units only for relatively high-transmittance W and / or G sub-pixels. The present invention selectively cuts a light emitting portion or a circuit portion having a defect among a plurality of light emitting portions and circuit portions included in the same sub-pixel through a cutting process to cut off electrical connections. In the present invention, a welding process as in the prior art is unnecessary when performing a repair operation, and the repair process can be simplified because the repair operation is performed only with the cutting process. Moreover, since the present invention includes a plurality of light emitting parts and circuit parts in the same sub-pixel and drives only the light emitting part and the circuit part without defects, it is possible to repair not only the circuit part defect but also the light emitting part defect.

On the other hand, in the present invention, the light emitting units and the circuit units in the same sub-pixel are electrically connected to each other to enable the repair process as described above. That is, a plurality of circuit parts included in the same sub-pixel share one data line and operate simultaneously by the same scan pulse to receive the same data voltage from the shared data line. In addition, each of the plurality of light emitting units included in the same sub-pixel is connected to all circuit units in the sub-pixel.

5A and 5B show examples in which a plurality of light emitting units and circuit units are respectively formed for a subpixel having high transmittance in an RWGB pixel structure in which a unit pixel is composed of four subpixels as shown in FIG. 4A.

Referring to FIG. 5A, in the RWGB pixel structure, each of the W light emitting part WE and the W circuit part WC of the W sub-pixel SPW is formed in plural. The W light emitting units WE may include first to kth (k is a positive integer greater than or equal to 2) W light emitting units WE1 to WEk. In addition, the W circuit unit WC may include first to k-th W circuit units WC1 to WCk.

Referring to FIG. 5B, in the RWGB pixel structure, a plurality of W light emitting units WE and W circuit parts WC of the W sub pixels SPW are formed, and a G light emitting unit GE of the G sub pixels SPG. ) And each of the G circuit portions GC are also formed in plural. The W light emitting units WE may include first to kth (k is a positive integer greater than or equal to 2) W light emitting units WE1 to WEk. In addition, the W circuit unit WC may include first to k-th W circuit units WC1 to WCk. The G light emitting part GE may include first to kth G light emitting parts GE1 to GEk. In addition, the G circuit unit GC may include first to kth G circuit units GC1 to GCk.

FIG. 6 shows an example in which a plurality of light emitting units and circuit units are respectively formed for a sub-pixel having high transmittance in an RGB pixel structure in which a unit pixel is composed of three sub-pixels as shown in FIG. 4B.

Referring to FIG. 6, in the RGB pixel structure, each of the G light emitting units GE and G circuit units GC of the G sub pixels SPG is formed in plural. The G light emitting part GE may include first to kth G light emitting parts GE1 to GEk. In addition, the G circuit unit GC may include first to kth G circuit units GC1 to GCk.

7A and 7B show a connection structure between a plurality of light emitting units and circuit units included in the same sub-pixel. 8A and 8B show the circuit structure of a sub-pixel employing the connection structure of FIGS. 7A and 7B, respectively.

Assuming that the high transmittance sub-pixel includes two light emitting units and two circuit units, respectively, as illustrated in FIG. 7A, the first light emitting unit, the first circuit unit, the second light emitting unit, and the second circuit unit may be connected through an “X” -shaped connection structure. They can be electrically connected to each other. 8A, the anode electrode of the first light emitting part OLED, the source node Ns of the first circuit part, the anode electrode of the second light emitting part OLED ', and the source node Ns of the second circuit part ') Are electrically connected to each other.

In addition, as shown in FIG. 7B, the first light emitting unit, the first circuit unit, the second light emitting unit, and the second circuit unit may be electrically connected to each other through an “H” -shaped connection structure. That is, as shown in FIG. 8B, the anode electrode of the first light emitting part OLED, the source node Ns of the first circuit part, the anode electrode of the second light emitting part OLED ', and the source node Ns of the second circuit part ') Are electrically connected to each other.

9 shows a repair process for removing a defective portion through a cutting process.

As illustrated in FIG. 9, the present invention can selectively deactivate a light emitting unit or a circuit unit having a defect among a plurality of light emitting units and circuit units included in the same sub-pixel through a cutting process.

For example, when it is determined that one of the two light emitting parts is defective as in (A) and (C) of FIG. 9, the present invention cuts the electrical connection to the bad light emitting part by a cutting process. At this time, the other normal light-emitting unit is commonly connected to the two circuit units to perform a normal light-emitting operation. Even if the normal light emitting portion is driven by two circuit portions, it does not cause any problem. This is because the two circuit parts share the same data line and operate simultaneously by the same scan pulse to receive the same data voltage.

In addition, as in (B) and (D) of FIG. 9, when one of the two circuit parts is determined to be defective, the present invention cuts the electrical connection to the defective circuit part by a cutting process. At this time, the other normal circuit unit may be connected to two light emitting units in common to drive all of the light emitting units. In this case, since the driving current generated by the normal circuit unit needs to be divided and supplied to the two light emitting units, it may be difficult to implement a desired gray level. According to the present invention, after such a repair position is previously stored in the repair process, data corresponding to the repair position may be appropriately compensated using a data compensation algorithm.

According to the present invention, by forming at least two light emitting units and circuit units for a sub-pixel having a high transmittance among sub-pixels in a unit pixel, a welding process may be omitted during a repair operation, thereby simplifying the repair process. In addition, it is possible to easily repair not only a defective circuit portion but also a defective light emitting portion.

Through the above description, those skilled in the art will appreciate that various changes and modifications are possible without departing from the technical idea of the present invention. Therefore, the technical scope of the present invention is not limited to the contents described in the detailed description of the specification, but should be determined by the scope of the claims.

11: First substrate 12: Second substrate
15: driver unit 16: signal lines
SP: sub-pixel

Claims (9)

A pixel array in which a plurality of sub-pixels are formed, each including a light emitting unit made of an organic light emitting diode, and a circuit unit including a driving TFT (Thin Film Transistor) and a plurality of switch TFTs controlling a driving current flowing through the organic light emitting diode;
A gate driver supplying a scan pulse to a gate line connected to the circuit unit; And
A data driver supplying a data voltage to a data line connected to the circuit unit;
At least one sub-pixel among the sub-pixels, the organic light emitting display device, characterized in that it comprises at least two or more of the light emitting portion and the circuit portion. According to claim 1,
When a unit pixel is composed of a plurality of sub-pixels,
The at least one sub-pixel is selected from among the sub-pixels in the unit pixel, a sub-pixel having a relatively high transmittance, characterized in that the organic light emitting display device. According to claim 1,
Multiple circuits included in the same sub-pixel,
An organic light emitting display device comprising one data line and simultaneously operating by the same scan pulse to receive the same data voltage from the shared data line. The method of claim 3,
Each of the plurality of light emitting units included in the same sub-pixel is connected to all the circuit units in the sub-pixel, the organic light emitting display device. According to claim 1,
An organic light emitting display device, wherein at least one light emitting part or circuit part among a plurality of light emitting parts and circuit parts included in the same sub-pixel is selectively disconnected by a cutting process. According to claim 1,
R sub-pixels, G sub-pixels, and B sub-pixels adjacent to each other in the sub-pixels constitute one unit pixel;
The G sub-pixel is an organic light emitting display device, characterized in that it comprises a plurality of circuit parts and a plurality of light-emitting parts electrically connected to each other. According to claim 1,
R sub-pixels, W sub-pixels, G sub-pixels, and B sub-pixels adjacent to each other in the sub-pixels constitute one unit pixel;
The W sub-pixel is an organic light emitting display device, characterized in that it comprises a plurality of circuit parts and a plurality of light-emitting parts electrically connected to each other. According to claim 1,
R sub-pixels, W sub-pixels, G sub-pixels, and B sub-pixels adjacent to each other in the sub-pixels constitute one unit pixel;
Each of the W sub-pixel and the G sub-pixel includes a plurality of circuit parts and a plurality of light-emitting parts electrically connected to each other. According to claim 1,
An organic light emitting display device characterized in that the plurality of light emitting units and circuit units included in the same sub-pixel are electrically connected to each other through an "X" -shaped connection structure or a "H" -shaped connection structure.

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