KR20170080345A - Organic light emitting display device and method for detecting bad sub pixel thereof - Google Patents

Abstract

A defective sub-pixel detection method according to the present invention is a method for detecting a defective sub-pixel by supplying a data voltage for sensing a first mobility to a normal pixel and outputting a data voltage for sensing a second mobility, And the like. Accordingly, the defective sub-pixel detection method according to the present invention can accurately detect the defective white sub-pixel even when the anode-cathode short-circuit resistance is extremely low.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting diode (OLED) display, and a method of detecting a defective sub-

The present invention relates to an organic light emitting display and a method for detecting defective sub-pixels thereof.

Recently, with the development of multimedia, the importance of flat panel display devices is increasing. In response to this, flat panel display devices such as liquid crystal display devices, plasma display devices, and organic light emitting display devices have been commercialized. Among such flat panel display devices, organic light emitting display devices have attracted attention as a next generation flat panel display device because they have a high response speed, low power consumption, and self light emission, so that there is no problem in viewing angle.

A general organic light emitting display includes a display panel including a plurality of pixels and a panel driver for emitting each pixel. Here, each pixel is formed in a pixel region defined by the intersection of a plurality of data lines and a plurality of scan lines.

Each of these pixels includes a switching transistor Tsw, a driving transistor Tdr, a capacitor Cst, and an organic light emitting diode OLED, as shown in Fig.

The switching transistor Tsw is switched according to the scan signal S supplied to the scan line SL and supplies the data voltage Vdata supplied to the data line DL to the drive transistor Tdr.

The driving transistor Tdr is switched according to the data voltage Vdata supplied from the switching transistor Tsw and controls the data current Ioled flowing to the organic light emitting element OLED by the driving voltage VDD.

The capacitor Cst is connected between the gate terminal and the source terminal of the driving transistor Tdr to store a voltage corresponding to the data voltage Vdata supplied to the gate terminal of the driving transistor Tdr, Tdr).

The organic light emitting diode OLED emits light according to the current supplied through the driving transistor Tdr. The anode electrode of the organic light emitting element OLED is connected to the source electrode of the driving transistor Tdr and the cathode electrode can be connected to the line to which the cathode voltage VSS is supplied.

The organic light emitting diode OLED may include an anode electrode, a hole transporting layer, an organic light emitting layer, an electron transporting layer, and a cathode electrode. have. In the organic light emitting diode OLED, when a voltage is applied to the anode electrode and the cathode electrode, holes and electrons move to the organic light emitting layer through the hole transporting layer and the electron transporting layer, respectively.

In such an organic light emitting diode OLED, an anode electrode and a cathode electrode are short-circuited due to a foreign material or the like, and therefore, they sometimes do not emit light.

The contents of the background art described above are technical information acquired by the inventor of the present invention for the derivation of the present invention or obtained in the derivation process of the present invention, There is no number.

An object of the present invention is to provide an organic light emitting display device capable of detecting defective pixels and a method of detecting defective pixels therefrom.

It is another object of the present invention to provide an organic light emitting display device capable of detecting defects of white sub-pixels and a method of detecting defective pixels thereof.

It is another object of the present invention to provide an organic light emitting display capable of detecting a failure of a white sub-pixel even if the resistance between the anode electrode and the cathode electrode is very small and a method of detecting a defective pixel thereof As a technical task.

According to an aspect of the present invention, there is provided a method for detecting a defective sub-pixel, the method including detecting a defective pixel among a plurality of pixels including a white sub-pixel, a red sub-pixel, a green sub- ; Supplying a data voltage for first mobility sensing to a normal pixel and supplying a data voltage for sensing a second mobility degree larger than the data voltage for sensing the first mobility to the detected defective pixel; Sensing a current of a driving transistor included in each of the plurality of pixels and outputting first sensing data; And detecting a failure of the white sub-pixel included in the defective pixel using the sensing data.

According to another aspect of the present invention, there is provided an OLED display including a plurality of pixels including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel; And supplying a data voltage for first mobility sensing to the sub-pixels included in the normal pixel among the plurality of pixels, and supplying the first mobility sensing data voltage to the sub-pixels included in the defective pixel among the plurality of pixels, And a data driver for supplying a second mobility sensing data voltage that is larger than the sensing data voltage.

According to the present invention, there is an effect that the detection power for defective pixels can be increased.

Further, according to the present invention, even when the resistance between the anode electrode and the cathode electrode is very small, it is possible to accurately determine whether or not the white sub-pixel is defective, thereby improving the quality of the panel.

Further, according to the present invention, there is another effect that the image quality improvement rate can be increased.

1 is a circuit diagram for explaining a pixel structure of a general organic light emitting display device.
2 is a schematic view illustrating an organic light emitting display according to an exemplary embodiment of the present invention.
FIG. 3 is a view schematically showing the pixel of FIG. 2. FIG.
Figure 4
Fig. 2 is a schematic view of an optical compensation system according to an embodiment of the present invention.
4 is a diagram showing a difference in sensing value between a defective sub-pixel and a normal sub-pixel in a general case.
FIG. 5 is a graph showing a difference in sensing value between a defective sub-pixel and a normal sub-pixel when the anode-cathode short-circuit resistance is low.
FIG. 6 is a graph showing a difference in sensing value between a defective sub-pixel and a normal sub-pixel when the second mobility sensing data voltage is applied.
7 is a flowchart illustrating a method of detecting a defective white sub-pixel according to an exemplary embodiment of the present invention.
8 is a flowchart showing a defective pixel detection method in a threshold voltage sensing mode.
9 is a flowchart showing a defect detection method for a white sub-pixel in the mobility sensing mode.

The meaning of the terms described herein should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms.

It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one.

The term "on" means not only when a configuration is formed directly on top of another configuration, but also when a third configuration is interposed between these configurations.

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

2 is a schematic view illustrating an organic light emitting display according to an exemplary embodiment of the present invention.

2, the OLED display includes a display panel 10, a data driver 20, a scan driver 30, a timing controller 40, and a memory 50 .

First, the display panel 10 includes a plurality of scan lines SL, a plurality of sensing lines SS, a plurality of data lines DL, a plurality of driving voltage lines PL, (RL) and a plurality of pixels (P).

The plurality of data lines DL may intersect the plurality of scan lines SL and the plurality of sensing lines SS. The plurality of scan lines SL and the plurality of sensing lines SS may be formed side by side.

The pixel P may be connected to any one of the data lines DL, any one of the driving voltage lines PL, and the reference voltage lines RL. Each of the pixels P of the display panel 10 includes a red sub-pixel emitting red light, a white sub-pixel emitting white light, a blue sub-pixel emitting blue light, and a green sub- .

Each of the pixels P of the display panel 10 includes an organic light emitting diode (OLED) and a pixel driver for supplying current to the organic light emitting diode OLED. 3, the pixel driving unit includes a driving transistor DT, a first transistor SCAN controlled by a scan signal of the scan line, a second transistor SENSE controlled by a sensing signal of the sensing line, And a capacitor.

The pixel P may be classified into a display mode, a threshold voltage sensing mode, and a mobility sensing mode. The pixel P is supplied with the light emission data voltage from the data line in the display mode and supplies current to the organic light emitting element OLED according to the light emission data voltage. As a result, in the display mode, the organic light emitting element OLED emits light.

In addition, the pixel P receives the data voltage for threshold voltage sensing from the data line in the threshold voltage sensing mode and senses the threshold voltage of the driving transistor DT according to the data voltage for threshold voltage sensing. Further, the pixel P receives the data voltage for detecting the mobility from the data line in the mobility sensing mode, and senses the current of the driving transistor DT according to the data voltage for mobility sensing.

The scan driver 30 is connected to a plurality of scan lines SL to supply scan signals. The scan driver 30 supplies scan signals to the plurality of scan lines SL according to a scan timing control signal input from the timing controller 40. [ The scan driver 30 may sequentially supply scan signals to the plurality of scan lines SL, and may include a shift register.

In addition, the scan driver 30 is connected to a plurality of sensing lines SS to supply sensing signals. The scan driver 30 supplies sensing signals to the plurality of sensing lines SS according to a sensing timing control signal input from the timing controller 40. [ The scan driver 30 may sequentially supply the sensing signals to the plurality of sensing lines SS, and in this case, may include a shift register.

The scan driver 424 may be mounted on a flexible film formed of a driving chip such as an integrated circuit and attached to the display panel 410 or may be mounted on a flexible printed circuit board including a gate driver In Panel ) Method in the non-display region of the display panel 410. [

The data driver 20 is connected to a plurality of data lines DL to supply data voltages. The data driver 20 receives the data timing control signal and correction data in the display mode. The data driver 20 converts the correction data into the light emission data voltages in accordance with the data timing control signal in the display mode, and supplies the light emission data voltages to the plurality of data lines DL. At this time, the emission data voltage is a voltage for emitting the organic light emitting element OLED of the pixel P with a predetermined luminance. When the correction data supplied to the data driver 20 is 8 bits, each of the data voltages may be supplied in any one of 256 voltages.

In addition, the data driver 20 receives the data timing control signal and the first sensing data in the threshold voltage sensing mode. The data driver 20 converts the first sensing data into a data voltage for threshold voltage sensing according to the data timing control signal in the threshold voltage sensing mode and supplies the data voltage to the plurality of data lines DL. At this time, the data voltage for threshold voltage sensing is a voltage supplied to the pixel P to sense the threshold voltage of the driving transistor DT of the pixel P. [

Also, the data driver 20 receives the data timing control signal, the second sensing data, or the third sensing data in the mobility sensing mode. The data driver 20 converts the second sensing data into the first mobility sensing data voltage according to the data timing control signal in the mobility sensing mode and supplies the data voltage to the plurality of data lines DL. The data driver 20 converts the third sensing data into the second mobility sensing data voltage according to the data timing control signal in the mobility sensing mode and supplies the data voltage to the plurality of data lines DL.

At this time, the first mobility sensing data voltage is a voltage supplied to the pixel P to sense the current of the driving transistor DT of the normal pixel P, and the second mobility sensing data voltage is the defective pixel P, which is supplied to the defective pixel P for sensing the current of the driving transistor DT, is larger than the first mobility sensing data voltage.

In one embodiment, the data voltage for sensing the second mobility may be as in Equation 1 below. That is, the data voltage for sensing the second mobility may correspond to a value obtained by multiplying the data voltage for sensing the first mobility by a constant greater than one.

[Equation 1]

MV1 represents a data voltage for sensing a first mobility, MV2 represents a data voltage for sensing a second mobility, and A may represent a constant greater than one.

For example, when the data voltages for first mobility sensing for the red subpixel, the white subpixel, the green subpixel, and the blue subpixel are 7V, 8V, 9V, and 10V, respectively, The data voltage for mobility sensing can be multiplied by 1.2 to give 8.4V, 9.6V, 10.8V, and 12V.

In another embodiment, the data voltage for sensing the second mobility may be calculated using Equation 2 using the reference sensing data. At this time, the reference sensing data may correspond to a mobility sensing value that is a reference for each of the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel.

[Equation 2]

MV1 represents a data voltage for sensing a first mobility, MV2 represents a data voltage for sensing a second mobility, and A may represent a constant greater than one. The ave (all) represents an average of the mobility sensing values of all the sub-pixels, and the ave (color) may represent an average of the color mobility sensing values.

That is, the second mobility sensing data voltage is obtained by multiplying the first mobility sensing data voltage by a constant larger than 1, multiplying the average of the mobility sensing values of all the sub-pixels, Which may correspond to divided values.

For example, if the data voltages for the first mobility sensing for the red subpixel, the white subpixel, the green subpixel, and the blue subpixel are 7V, 8V, 9V, 10V and the average of the mobility sensing values is 480, , 480 is called. The data voltage for sensing the second mobility is a value obtained by multiplying the first mobility sensing data voltage by 1.2 times 8.4 V, 9.6 V, 10.8 V, and 12 V to a total average of 492 and dividing the average of the color mobility sensing values by 8.61 V, 9.15V, 10.8V, 12.3V.

On the other hand, the data voltages for sensing the first and second mobility are inversely proportional to the width of the driving transistor DT of the sub-pixel. If the width of the driving transistor DT is the largest in the red sub-pixel and then in the order of the white sub-pixel, the green sub-pixel and the blue sub-pixel, the data voltage for the first mobility sensing has the largest blue sub- Sub pixels, and white sub pixels. Accordingly, the data voltages for sensing the second mobility are also determined in the order of the blue sub-pixel, the green sub-pixel, and the white sub-pixel.

The data driver 20 is connected to the reference voltage lines RL and senses the source voltage of the driving transistor DT from each of the reference voltage lines RL and outputs the sensed voltage as first sensing data, Conversion. Further, the data driver 20 converts the current flowing in each of the reference voltage lines RL into a voltage, and converts the converted voltage into second sensing data, which is digital data.

To this end, the data driver 20 may include a current-to-voltage converter for converting a current flowing in each of the reference voltage lines RL into a voltage. The data driver 20 converts the source voltage of the driving transistor DT into first sensing data, which is digital data, and converts the output voltage of the current-voltage converter into second sensing data, which is digital data. (analog digital converters).

The data driver 20 outputs the first sensing data or the second sensing data to the timing controller 40.

The data driver 20 may be mounted on a flexible film formed of a driving chip such as an integrated circuit and attached to the display panel 10, or may be directly bonded to the display panel 10.

The timing control unit 40 receives the digital video data, the first sensing data, or the second sensing data and the timing signal. The timing signal may include a vertical sync signal, a horizontal sync signal, a data enable signal, and a dot clock.

The timing controller 40 generates timing control signals for controlling the operation timings of the scan driver 30 and the data driver 20. The timing control signals include a data timing control signal for controlling the operation timing of the data driver 20, a scan timing control signal for controlling the operation timing of the scan driver 30, and a sensing timing control signal.

The timing controller 40 operates the scan driver 30 and the data driver 20 in any one of a display mode, a threshold voltage sensing mode, and a mobility sensing mode according to a mode signal.

The display mode is a mode in which the pixels P of the display panel 10 display an image. The threshold voltage sensing mode is a mode for sensing the source voltage of the driving transistor DT in order to sense the threshold voltage of the driving transistor DT of each of the pixels P of the display panel 10. [ Since the threshold voltage of the driving transistor DT can be shifted due to a process variation at the time of manufacturing or long-time driving, the threshold voltage compensation of the driving transistor DT is required. The mobility sensing mode is a mode for sensing the current of the driving transistor DT of each of the pixels P of the display panel 10. [

When the waveform of the scan signal and the waveform of the sensing signal supplied to each of the pixels P in the display mode, the threshold voltage sensing mode, and the mobility sensing mode are changed, the display mode, the threshold voltage sensing mode, The data timing control signal, the scan timing control signal, and the sensing timing control signal may also be changed. Accordingly, the timing controller 40 generates a data timing control signal, a scan timing control signal, and a sensing timing control signal according to whether the mode is the display mode, the threshold voltage sensing mode, or the mobility sensing mode.

The timing controller 40 generates a mode signal depending on whether the scan driver 30 and the data driver 20 are driven in a display mode, a threshold voltage sensing mode, or a mobility sensing mode. The timing controller 40 internally operates the scan driver 30 and the data driver 20 in any one of a display mode, a threshold voltage sensing mode, and a mobility sensing mode according to a mode signal.

The timing controller 40 outputs the correction data, the first sensing data, the second sensing data, or the third sensing data and the data timing control signal to the data driver 20. The timing controller 40 outputs a scan timing control signal to the scan driver 30. The timing controller 40 outputs a sensing timing control signal to the scan driver 30.

The timing controller 40 outputs the first sensing data and the data timing control signal to the data driver 20 in the threshold voltage sensing mode. The timing controller 40 receives the first sensing data from the data driver 20 and determines whether the pixel P is defective by using the first sensing data. When the first sensing data exceeds the preset first threshold value, the timing controller 40 determines that the pixel including the corresponding sub-pixel is a defective pixel. Then, the timing controller 40 stores the first sensing data and the defective pixel data in the memory 50.

In addition, the timing controller 40 outputs the second sensing data or the third sensing data and the timing control signal to the data driver 20 in the mobility sensing mode. The second sensing data is digital data for sensing the mobility of the driving transistor DT with respect to the normal pixel and the third sensing data is digital data for sensing the mobility of the driving transistor DT with respect to the defective pixel. to be.

The timing controller 40 receives the second sensing data from the data driver 20 and determines whether the white pixel among the defective pixels is defective by using the second sensing data. The timing controller 40 subtracts the second sensing data of the white sub-pixel from the second sensing data having the smallest value among the second sensing data of the red sub-pixel, the green sub-pixel and the blue sub-pixel included in the defective pixel Exceeds the second threshold, it is determined that the white sub-pixel is defective.

On the other hand, the timing controller 40 receives digital video data from the outside in the display mode, and corrects the digital video data into correction data using the compensation data stored in the memory 50. [ At this time, the compensation data is data for compensating white light for a pixel whose white sub-pixel is defective, and may include a ratio for the red sub-pixel, the green sub-pixel, and the blue sub-pixel.

The organic light emitting display according to the present invention is characterized in that a data voltage for sensing the mobility of a normal pixel and a defective pixel is supplied differently in the mobility sensing mode. The organic light emitting display according to the present invention supplies the first mobility sensing data voltage to the normal pixel in the mobility sensing mode and supplies the second mobility sensing data voltage .

The defective pixel is a pixel in which at least one of the red subpixel, the white subpixel, the green subpixel, and the blue subpixel is defective. Generally, even if the data voltage for sensing the first mobility is supplied, A difference in sensing value between the defective sub-pixel and the normal sub-pixel clearly appears.

Referring to FIG. 4, the data driver 20 supplies the data voltages for the first mobility sensing to the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel, respectively. The data driver 20 converts the current of the driving transistor DT of each sub pixel into a voltage and converts the converted voltage into second sensing data which is digital data.

In FIG. 4, the second sensing data of each of the red sub-pixel, the white sub-pixel, the green sub-pixel and the blue sub-pixel is shown in the table. As shown in the table, the red sub-pixel, the green sub-pixel and the blue sub-pixel are normal sub-pixels, and the second sensing data is close to the sensing target value of 390, 399 and 395, And the second sensing data is represented by 0. That is, the second sensing data difference between the normal sub-pixel and the white sub-pixel is large.

However, when the short-circuiting resistance between the cathode electrode and the anode electrode included in the defective sub-pixel is very low, other normal sub-pixels may be affected, so that the sensing value may be lower than a normal sub-pixel.

5, when the short-circuit resistance between the cathode electrode and the anode electrode included in the defective sub-pixel is very low, the second sensing data of the red sub-pixel, the white sub-pixel, the green sub- 0 ". In this case, it is impossible to determine which one of the red subpixel, the white subpixel, the green subpixel, and the blue subpixel is defective, so that it is difficult to appropriately cope with the defective subpixel.

In order to solve this problem, the organic light emitting display according to the present invention supplies a data voltage for sensing a mobility higher than a normal pixel with respect to a defective pixel as described above.

The OLED display device according to the present invention can increase the charging capability of the normal sub-pixel by supplying the data voltage for sensing the mobility of the defective pixel to a voltage higher than the data voltage for sensing the mobility of the normal pixel. Accordingly, even when the short-circuiting resistance between the cathode electrode and the anode electrode included in the defective sub-pixel is extremely low, as shown in Fig. 6, the normal sub-pixel acquires the normal second sensing data without being affected by the defective pixel .

7 is a flowchart illustrating a method of detecting a defective white sub-pixel according to an exemplary embodiment of the present invention.

Referring to FIG. 7, an OLED display according to an exemplary embodiment of the present invention detects a defective pixel in a threshold voltage sensing mode (S701).

Hereinafter, a method of detecting defective pixels will be described in more detail with reference to FIG.

8 is a flowchart showing a defective pixel detection method in a threshold voltage sensing mode.

Referring to FIG. 8, the organic light emitting display supplies a data voltage for threshold voltage sensing to a plurality of data lines DL in a threshold voltage sensing mode (S801). The threshold voltage sensing data voltage is a voltage supplied to the pixel P to sense the threshold voltage of the driving transistor DT of the pixel P. [

The organic light emitting display device senses the source voltage of the driving transistor DT from each of the reference voltage lines RL and converts the sensed voltage into first sensing data which is digital data.

Next, when the first sensing data exceeds a first threshold value set in advance, the organic light emitting display device determines that the pixel including the corresponding sub-pixel is a defective pixel (S802 and S803). Then, the organic light emitting display device stores the first sensing data and the defective pixel data in the memory 50.

On the other hand, if the first sensing data does not exceed the preset first threshold value, the organic light emitting display device determines that the image sensor is normalized (S802 and S804).

Referring again to FIG. 7, in step S702, the organic light emitting display determines whether a white sub-pixel among the defective pixels is defective in the mobility sensing mode.

Hereinafter, a defect detection method for a white sub-pixel in the mobility sensing mode will be described in more detail with reference to FIG.

9 is a flowchart showing a defect detection method for a white sub-pixel in the mobility sensing mode.

Referring to FIG. 9, the organic light emitting display device supplies a data voltage for mobility sensing to a plurality of data lines DL in a mobility sensing mode. At this time, the organic light emitting display supplies the first mobility sensing data voltage to the normal pixel and the second mobility sensing data voltage to the defective pixel (S901 to S903).

The first mobility sensing data voltage is a voltage supplied to the pixel P to sense the current of the driving transistor DT of the normal pixel P and the second mobility sensing data voltage is the voltage Is a voltage supplied to the defective pixel P for sensing the current of the transistor DT and is larger than the first mobility sensing data voltage.

In one embodiment, the second mobility sensing data voltage may be equal to Equation (1). That is, the second mobility sensing data voltage may correspond to a value obtained by multiplying the first mobility sensing data voltage by a constant greater than one.

In another embodiment, the second mobility sensing data voltage may be calculated using Equation 2 using the reference sensing data. That is, the second mobility sensing data voltage is obtained by multiplying the first mobility sensing data voltage by a constant greater than 1 and multiplying the average of the mobility sensing values of all the sub-pixels by the average value of the mobility sensing values ≪ / RTI >

The organic light emitting display device converts a current flowing in each of the reference voltage lines RL into a voltage and converts the converted voltage into second sensing data which is digital data.

Next, the OLED display subtracts the second sensing data of the white sub-pixel from the second sensing data having the smallest value among the second sensing data of the red sub-pixel, the green sub-pixel and the blue sub-pixel included in the defective pixel When the value exceeds the second threshold value, it is determined that the white sub-pixel is bad (S904 to S906).

On the other hand, in the OLED display device, the second sensing data having the minimum value among the second sensing data of the red sub-pixel, the green sub-pixel, and the blue sub-pixel included in the defective pixel is subtracted from the second sensing data of the white sub- If the value does not exceed the second threshold value, it is determined that one of the red sub-pixel, the green sub-pixel, and the blue sub-pixel is defective (S905 and S907).

Referring again to FIG. 7, when digital video data is inputted from the outside, the organic light emitting display device corrects the digital video data into correction data by using compensation data (S703). At this time, the compensation data is for compensating white light for a pixel including a defective white sub-pixel, and may include a ratio for a red sub-pixel, a green sub-pixel and a blue sub-pixel.

The organic light emitting display converts the correction data into light emission data voltages and supplies the light emission data voltages to a plurality of data lines DL. At this time, the emission data voltage is a voltage for emitting the organic light emitting element OLED of the pixel P with a predetermined luminance.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. Will be clear to those who have knowledge of. Therefore, the scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention.

10: Display panel
20:
30: a scan driver
40:
50: Memory

Claims (10)

Detecting a defective pixel among a plurality of pixels including a white sub-pixel, a red sub-pixel, a green sub-pixel, and a blue sub-pixel;
Supplying a data voltage for first mobility sensing to a normal pixel and supplying a data voltage for sensing a second mobility degree larger than the data voltage for sensing the first mobility to the detected defective pixel;
Sensing a current of a driving transistor included in each of the plurality of pixels and outputting first sensing data; And
And detecting a failure of the white sub-pixel included in the defective pixel using the sensing data. 2. The method as claimed in claim 1,
Wherein the data voltage for sensing the first mobility corresponds to a value obtained by multiplying the data voltage for sensing the first mobility by a constant greater than one. 2. The method as claimed in claim 1,
Wherein the first mobility sensing data voltage is a value obtained by multiplying a value obtained by multiplying the first mobility sensing data voltage by a constant greater than 1 and multiplying the average of the reference sensing data of all the sub pixels by an average of the reference sensing data. Detection method. The method of claim 1, wherein the detecting of the defective pixel comprises:
Sensing a threshold voltage of a driving transistor included in each of the plurality of pixels and outputting second sensing data; And
And detecting, as a bad pixel, a pixel including the sub-pixel in which the second sensing data of the plurality of pixels exceeds a first threshold value. 2. The method of claim 1, wherein detecting the failure of the white sub-
A value obtained by subtracting the first sensing data of the white sub-pixel from the first sensing data having the minimum value among the first sensing data of the red sub-pixel, the green sub-pixel and the blue sub-pixel included in the defective pixel, Pixel, the white sub-pixel among the sub-pixels included in the defective pixel is determined to be defective. A plurality of pixels including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel; And
And supplies the data voltage for first mobility sensing to the sub-pixels included in the normal pixel among the plurality of pixels, and supplies the first mobility sensing data voltage to the sub-pixels included in the defective pixel among the plurality of pixels, And a data driver for supplying a data voltage for sensing a second mobility that is larger than the data voltage for the second mobility. 7. The method as claimed in claim 6,
And the data corresponding to the first mobility sensing data voltage is multiplied by a constant larger than one. 7. The method as claimed in claim 6,
Wherein the first mobility sensing data voltage is a value obtained by multiplying a value obtained by multiplying the first mobility sensing data voltage by a constant greater than 1 and multiplying the average of the reference sensing data of all the sub pixels by an average of reference sensing data. Device. The method according to claim 6,
Further comprising a timing controller for sensing the current of the driving transistor included in each of the plurality of pixels and detecting a failure of the white sub-pixel included in the defective pixel by using the sensed data outputted from the timing controller. Device. The apparatus of claim 9,
If the value obtained by subtracting the sensing data of the white sub-pixel from the sensing data having the minimum value among the sensing data of the red sub-pixel, the green sub-pixel and the blue sub-pixel included in the defective pixel exceeds a threshold value, And determines that the white sub-pixel among the included sub-pixels is defective.

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