KR102366300B1 - Organic light emitting display device and method for detecting bad sub pixel thereof - Google Patents

Abstract

An organic light emitting diode display and a method for detecting a bad sub-pixel thereof according to the present invention supply a first mobility sensing data voltage to a normal pixel and a second movement greater than the first mobility sensing data voltage to a bad pixel It is also technically characterized to supply a data voltage for sensing. Accordingly, the organic light emitting diode display and the method for detecting a bad sub-pixel according to the present invention can accurately detect a bad white sub-pixel even when the anode-cathode short circuit resistance is very low.

Description

Organic light emitting display device and method for detecting defective sub-pixels thereof

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

Recently, with the development of multimedia, the importance of a flat panel display is increasing. In response to this, flat panel display devices such as a liquid crystal display device, a plasma display device, and an organic light emitting display device have been commercialized. Among these flat panel displays, the organic light emitting diode display has a high response speed, low power consumption, and has no problem in a viewing angle because it is self-luminous, and thus attracts attention as a next-generation flat panel display.

A general organic light emitting diode display includes a display panel including a plurality of pixels and a panel driver emitting light from each pixel. Here, each pixel is formed in a pixel area 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. 1 .

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

The driving transistor Tdr is switched according to the data voltage Vdata supplied from the switching transistor Tsw to control the data current Ioled flowing to the organic light emitting diode 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, and use the stored voltage to the driving transistor ( Tdr) is turned on.

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

An 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. there is. In an organic light emitting diode (OLED), when a voltage is applied to an anode electrode and a cathode electrode, holes and electrons move to the organic light emitting layer through the hole transport layer and the electron transport layer, respectively, and combine with each other in the organic light emitting layer to emit light.

In such an organic light emitting diode (OLED), the anode electrode and the cathode electrode are short-circuited due to a foreign material, etc., and thus the organic light emitting diode (OLED) does not emit light.

The content of the background art described above is technical information possessed by the inventor of the present application for the purpose of derivation of the present invention or acquired in the process of derivation of the present invention, and is necessarily known as known technology disclosed to the general public prior to the filing of the present invention. can't

An object of the present invention is to provide an organic light emitting display device capable of detecting a bad pixel and a method for detecting a bad pixel thereof.

Another object of the present invention is to provide an organic light emitting display device capable of detecting a defect in a white sub-pixel and a method for detecting a defective pixel thereof in order to solve the above-described problem.

In addition, the present invention provides an organic light emitting display device capable of detecting a defect in a white sub-pixel even when the resistance between an anode electrode and a cathode electrode is very small, and a method of detecting a defective pixel thereof, in order to solve the above problem make it a technical task.

A method for detecting a bad sub-pixel according to an aspect of the present invention for achieving the above technical problem is to detect a bad pixel among a plurality of pixels including a white sub-pixel, a red sub-pixel, a green sub-pixel, and a blue sub-pixel. to do; supplying a first mobility sensing data voltage to the normal pixel and supplying a second mobility sensing data voltage greater than the first mobility sensing data voltage to the detected bad pixel; outputting first sensed data by sensing a current of a driving transistor included in each of the plurality of pixels; and detecting a defect in the white sub-pixel included in the defective pixel by using the sensing data.

According to another aspect of the present invention, an organic light emitting diode display device includes: 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 first mobility sensing data voltage to sub-pixels included in a normal pixel among the plurality of pixels, and providing the first mobility sensing data voltage to sub-pixels included in a bad pixel among the plurality of pixels. and a data driver supplying a data voltage for sensing a second mobility greater than the data voltage for sensing.

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

In addition, 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 the white sub-pixel is defective, and thus, there is another effect that the quality of the panel can be improved.

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

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

The meaning of the terms described in this specification should be understood as follows.

The singular expression is to be understood as including the plural expression unless the context clearly defines otherwise, and the terms "first", "second", etc. are used to distinguish one element from another, The scope of rights should not be limited by these terms.

It should be understood that terms such as “comprise” or “have” do not preclude the possibility of addition or existence of one or more other features or numbers, steps, operations, components, parts, or combinations thereof.

The term “at least one” should be understood to include all possible combinations of one or more related items. For example, the meaning of “at least one of the first, second, and third items” means that each of the first, second, or third items as well as two of the first, second and third items It means a combination of all items that can be presented from more than one.

The term “on” is meant to include not only cases in which a certain component is formed directly above another component, but also a case in which a third component is interposed between these components.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the drawings.

2 is a diagram schematically illustrating an organic light emitting display device according to an embodiment of the present invention.

Referring to FIG. 2 , an organic light emitting diode display according to an exemplary embodiment 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, and a plurality of reference voltage lines. It includes the pixels RL and the plurality of pixels P.

The plurality of data lines DL may cross 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.

In addition, the pixel P may be connected to any one of the data lines DL, any one of the driving voltage lines PL, and any one of 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-pixel emitting green light. include

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

The pixel P may operate in a display mode, a threshold voltage sensing mode, and a mobility sensing mode. The pixel P receives a light emitting data voltage from a data line in the display mode, and supplies a current to the organic light emitting diode OLED according to the light emitting data voltage. Accordingly, in the display mode, the organic light emitting diode (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 sensing the threshold voltage. Furthermore, in the mobility sensing mode, the pixel P receives the data voltage for mobility sensing from the data line, and senses the current of the driving transistor DT according to the data voltage for mobility sensing.

The scan driver 30 is connected to the 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 in this case, may include a shift register.

Also, the scan driver 30 is connected to the 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 sensing signals to the plurality of sensing lines SS, and in this case, may include a shift register.

The scan driver 424 is formed of a driving chip such as an integrated circuit and mounted on a flexible film attached to the display panel 410 , or includes a plurality of transistors and a gate driver in panel (GIP). ) may be directly formed in the non-display area of the display panel 410 .

The data driver 20 is connected to the plurality of data lines DL to supply data voltages. The data driver 20 receives a data timing control signal and correction data in the display mode. The data driver 20 converts the correction data into light emitting data voltages according to the data timing control signal in the display mode and supplies the converted data to the plurality of data lines DL. In this case, the emission data voltage is a voltage for emitting light with a predetermined luminance of the organic light emitting diode (OLED) of the pixel (P). When the correction data supplied to the data driver 20 is 8 bits, each of the data voltages may be supplied as 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 threshold voltage sensing data voltage according to the data timing control signal in the threshold voltage sensing mode and supplies the data to the plurality of data lines DL. In this case, 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.

In addition, the data driver 20 receives the data timing control signal and the second sensing data or the third sensing data in the mobility sensing mode. The data driver 20 converts the second sensing data into a first mobility sensing data voltage according to the data timing control signal in the mobility sensing mode, and supplies it to the plurality of data lines DL. The data driver 20 converts the third sensing data into a second mobility sensing data voltage according to the data timing control signal in the mobility sensing mode and supplies the data 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 bad pixel ( As a voltage supplied to the bad pixel P to sense the current of the driving transistor DT of P), it is greater than the data voltage for first mobility sensing.

In an embodiment, the data voltage for the second mobility sensing may be as shown in Equation 1 below. 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.

[Formula 1]

The MV1 may represent a first mobility sensing data voltage, MV2 may represent a second mobility sensing data voltage, and A may represent a constant greater than 1.

For example, if the first mobility sensing data voltages for each of the red sub-pixel, white sub-pixel, green sub-pixel, and blue sub-pixel are 7V, 8V, 9V, and 10V, the second mobility-sensing data voltage is the first The value obtained by multiplying the data voltage for mobility sensing by 1.2 may be 8.4V, 9.6V, 10.8V, or 12V.

In another embodiment, the data voltage for the second mobility sensing may be calculated as in Equation 2 below by using the reference sensing data. In this case, the reference sensing data may correspond to a mobility sensing value serving as a reference for each of the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel.

[Equation 2]

The MV1 may represent a first mobility sensing data voltage, MV2 may represent a second mobility sensing data voltage, and A may represent a constant greater than 1. The ave(all) may represent an average of the mobility sensed values of all sub-pixels, and the ave(color) may represent an average of the mobility sensed values for each color.

That is, the second mobility sensing data voltage is obtained by multiplying the first mobility sensing data voltage by a constant constant greater than 1 multiplied by the average of the mobility sensing values of all sub-pixels, and the average of the mobility sensing values for each color It may correspond to the divided value.

For example, the first mobility sensing data voltages for each of the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel are 7V, 8V, 9V, and 10V, and the average of the mobility sensing values is 480, 516, 492 , is called 480. The data voltage for the second mobility sensing is a value obtained by multiplying the first mobility sensing data voltage by 1.2 by the overall average of 492 multiplied by 8.4V, 9.6V, 10.8V, and 12V, and dividing the average of the mobility sensing values by color 8.61 V, may correspond to 9.15V, 10.8V, 12.3V.

Meanwhile, the first and second data voltages for mobility sensing 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, followed by the white sub-pixel, the green sub-pixel, and the blue sub-pixel, the blue sub-pixel has the largest data voltage for the first mobility sensing, followed by the green sub-pixel. The size is determined in the order of the sub-pixel and the white sub-pixel. Accordingly, the size of the second data voltage for mobility sensing is 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, senses the source voltage of the driving transistor DT from each of the reference voltage lines RL, and converts the sensed voltage to first sensing data as digital data. convert Also, the data driver 20 converts the current flowing through each of the reference voltage lines RL into a voltage, and converts the converted voltage into second sensing data that is digital data.

To this end, the data driver 20 may include a current-voltage converter that converts a current flowing through each of the reference voltage lines RL into a voltage. In addition, the data driver 20 converts the source voltage of the driving transistor DT into first sensed data that is digital data, and an analog-to-digital converter that converts the output voltage of the current-voltage converter into second sensed data that is digital data. (analog digital converter) may be included.

In addition, the data driver 20 outputs the first sensed data or the second sensed data to the timing controller 40 .

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

The timing controller 40 receives digital video data, first sensing data, or second sensing data and a 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 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 each of the driving transistors DT of the pixels P of the display panel 10 . Since the threshold voltage of the driving transistor DT may be shifted due to a manufacturing process deviation or long-term driving, it is necessary to compensate the threshold voltage of the driving transistor DT. The mobility sensing mode is a mode for sensing the current of each of the driving transistors DT of the pixels P of the display panel 10 .

When the waveform of the scan signal supplied to each of the pixels P and the waveform of the sensing signal are changed in each of the display mode, the threshold voltage sensing mode, and the mobility sensing mode, the display mode, the threshold voltage sensing mode, and the mobility sensing mode, respectively In , 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 any of the display mode, the threshold voltage sensing mode, and the mobility sensing mode.

In addition, the timing controller 40 generates a mode signal according to which mode of the display mode, the threshold voltage sensing mode, and the mobility sensing mode to drive the scan driver 30 and the data driver 20 . 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 correction data, first sensing data, second sensing data, or third sensing data, and a 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 a data timing control signal to the data driver 20 in the threshold voltage sensing mode. Then, the timing controller 40 receives the first sensing data from the data driver 20 , and determines whether each of the pixels P is defective by using the input first sensing data. When the first sensing data exceeds a preset first threshold, the timing controller 40 determines that a pixel including the corresponding sub-pixel is a bad pixel. In addition, the timing controller 40 stores the first sensing data and the bad pixel data in the memory 50 .

In addition, the timing control unit 40 outputs the second sensing data or the third sensing data and the timing control signal to the data driving unit 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 bad pixel. am.

Then, the timing controller 40 receives the second sensing data from the data driver 20 , and determines whether the white sub-pixel is defective among the defective pixels by using the input second sensing data. The timing controller 40 subtracts the second sensed data of the white subpixel from the second sensed data having a minimum value among second sensed data of each of the red subpixel, the green subpixel, and the blue subpixel included in the bad pixel. If this second threshold is exceeded, it is determined that the white sub-pixel is defective.

Meanwhile, the timing controller 40 receives digital video data from the outside in the display mode, and corrects the digital video data as correction data using the compensation data stored in the memory 50 . In this case, the compensation data is data for compensating for white light with respect to a pixel having a defective white sub-pixel, and may include ratios of a red sub-pixel, a green sub-pixel, and a blue sub-pixel.

The organic light emitting display device according to the present invention is characterized in that, in the mobility sensing mode, data voltages for mobility sensing are differently supplied to normal pixels and bad pixels. The organic light emitting display device according to the present invention supplies a first mobility sensing data voltage to a normal pixel in a mobility sensing mode and a second movement sensing data voltage greater than the first mobility sensing data voltage to a bad pixel to supply

A bad pixel is a pixel in which at least one of a red sub-pixel, a white sub-pixel, a green sub-pixel, and a blue sub-pixel is defective. A difference in sensing values between the bad sub-pixel and the normal sub-pixel is clearly visible.

Referring to FIG. 4 , the data driver 20 supplies the first mobility sensing data voltage to each of the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel. 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 that is digital data.

In FIG. 4 , 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. Referring to the table, the red sub-pixel, the green sub-pixel, and the blue sub-pixel are normal sub-pixels, and the second sensed data is 390, 399, and 395 close to the sensing target values, whereas the white sub-pixel is a bad sub-pixel, The second sensed data appears as 0. That is, there is a large difference in the second sensed data between the normal sub-pixel and the white sub-pixel.

However, when the short-circuit resistance between the cathode electrode and the anode electrode included in the bad sub-pixel is very low, the sensing value may appear low even in the normal sub-pixel by affecting other normal sub-pixels.

Referring to FIG. 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 each of the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel is all appears close to 0. In this case, it is impossible to determine which sub-pixel among the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel is defective, so that it is difficult to properly deal with the defective sub-pixel.

In order to solve this problem, the organic light emitting display device according to the present invention supplies a data voltage for sensing mobility greater than that of a normal pixel to a bad pixel as described above.

The organic light emitting display device according to the present invention can increase the charging capacity of the normal sub-pixels by supplying a mobility sensing data voltage for a defective pixel to a greater value than a mobility sensing data voltage for a normal pixel. Accordingly, even when the short-circuit resistance between the cathode electrode and the anode electrode included in the bad sub-pixel is very low, as shown in FIG. 6 , the normal sub-pixel is not affected by the bad pixel and can acquire normal second sensing data. can

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

Referring to FIG. 7 , first, the organic light emitting display device according to an embodiment of the present invention detects a bad pixel in the threshold voltage sensing mode ( S701 ).

Hereinafter, a method of detecting a bad pixel will be described in more detail with reference to FIG. 8 .

8 is a flowchart illustrating a method for detecting a bad pixel in a threshold voltage sensing mode.

Referring to FIG. 8 , the organic light emitting diode display supplies a threshold voltage sensing data voltage to a plurality of data lines DL in the 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 diode display senses the source voltage of the driving transistor DT from each of the reference voltage lines RL, and converts the sensed voltage into first sensed data that is digital data.

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

On the other hand, when the first sensing data does not exceed the first threshold value, the organic light emitting display device determines that the pixel is a normal pixel ( S802 and S804 ).

Referring again to FIG. 7 , next, the organic light emitting display device determines whether the white sub-pixel among the bad pixels is defective in the mobility sensing mode ( S702 ).

Hereinafter, a method for detecting a defect with respect to a white sub-pixel in the mobility sensing mode will be described in more detail with reference to FIG. 9 .

9 is a flowchart illustrating a defect detection method for a white sub-pixel in a 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 device supplies a first mobility sensing data voltage to a normal pixel and supplies a second mobility sensing data voltage to a bad 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 driving the defective pixel P As a voltage supplied to the bad pixel P to sense the current of the transistor DT, it is greater than the first mobility sensing data voltage.

In an embodiment, the second mobility sensing data voltage may be the same as in Equation 1 above. 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 as in Equation 2 using the reference sensing data. That is, the second mobility sensing data voltage is obtained by multiplying a value obtained by multiplying the first mobility sensing data voltage by a constant greater than 1 by the average of the mobility sensing values of all sub-pixels, and dividing the average of the mobility sensing values for each color can correspond to

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

Next, in the organic light emitting display device, the second sensing data of the white sub-pixel is subtracted from the second sensing data having the minimum value among the second sensing data of each of the red sub-pixel, the green sub-pixel, and the blue sub-pixel included in the bad pixel If the value exceeds the second threshold, it is determined that the white sub-pixel is bad ( S904 to S906 ).

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

Referring again to FIG. 7 , when digital video data is inputted from the outside, the organic light emitting display corrects the digital video data into correction data using the compensation data ( S703 ). In this case, the compensation data is for compensating for white light with respect to a pixel including a defective white sub-pixel, and ratios for a red sub-pixel, a green sub-pixel, and a blue sub-pixel may be included.

The organic light emitting diode display converts the correction data into light emitting data voltages and supplies the converted data to the plurality of data lines DL. In this case, the emission data voltage is a voltage for emitting light with a predetermined luminance of the organic light emitting diode (OLED) of the pixel (P).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention pertains that various substitutions, modifications and changes are possible without departing from the technical matters of the present invention. It will be clear to those who have the knowledge of Therefore, the scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

10: display panel
20: data driving unit
30: scan driving unit
40: timing control
50: memory

Claims (10)

detecting a bad pixel from 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 first mobility sensing data voltage to the normal pixel and supplying a second mobility sensing data voltage greater than the first mobility sensing data voltage to the detected bad pixel;
outputting first sensed data by sensing a current of a driving transistor included in each of the plurality of pixels; and
and detecting a defect in the white sub-pixel included in the defective pixel by using the sensing data. According to claim 1, wherein the data voltage for the second mobility sensing,
The method for detecting a bad sub-pixel, characterized in that it corresponds to a value obtained by multiplying the first mobility sensing data voltage by a constant greater than 1. According to claim 1, wherein the data voltage for the second mobility sensing,
Bad sub-pixel, characterized in that it corresponds to a value obtained by multiplying the first mobility sensing data voltage by a constant greater than 1 by the average of the reference sensing data of all sub-pixels and dividing the average of the reference sensing data for each color detection method. The method of claim 1, wherein the detecting of the bad pixel comprises:
outputting second sensed data by sensing a threshold voltage of a driving transistor included in each of the plurality of pixels; and
and detecting, among the plurality of pixels, a pixel including a sub-pixel in which the second sensing data exceeds a first threshold value as a bad pixel. The method of claim 1 , wherein the detecting of the defect of the white sub-pixel comprises:
A value obtained by subtracting the first sensing data of the white sub-pixel from the first sensing data having a minimum value among the first sensing data of each of the red sub-pixel, the green sub-pixel, and the blue sub-pixel included in the bad pixel is a second threshold value exceeds, it is determined that the white sub-pixel among the sub-pixels included in the bad pixel is defective. a plurality of pixels including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel; and
A first mobility sensing data voltage is supplied to sub-pixels included in a normal pixel among the plurality of pixels, and the first mobility is sensed to sub-pixels included in a bad pixel among the plurality of pixels An organic light emitting diode display comprising a data driver supplying a data voltage for sensing a second mobility greater than a data voltage for use. The method of claim 6, wherein the data voltage for the second mobility sensing is,
and a value corresponding to a value obtained by multiplying the first mobility sensing data voltage by a constant greater than one. The method of claim 6, wherein the data voltage for the second mobility sensing is,
An organic light emitting display, characterized in that it corresponds to a value obtained by multiplying the first mobility sensing data voltage by a constant greater than 1 by the average of the reference sensing data of all sub-pixels and dividing the average of the reference sensing data for each color Device. 7. The method of claim 6,
The organic light emitting display according to claim 1, further comprising: a timing controller configured to detect a defect in the white sub-pixel included in the defective pixel by using the sensed data output by sensing the current of the driving transistor included in each of the plurality of pixels Device. The method of claim 9, wherein the timing control unit,
When 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 each of the red sub-pixel, the green sub-pixel, and the blue sub-pixel included in the bad pixel exceeds a threshold value, the An organic light emitting display device, characterized in that it is determined that a white sub-pixel among the included sub-pixels is defective.

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