KR102649826B1 - Organic light emitting display device and driving method for the same - Google Patents

Abstract

The present invention relates to an organic light emitting display device and a driving method for compensating data voltage based on the amount of current flowing in a driving power line. An organic light emitting display device according to an embodiment of the present invention includes a display panel including pixels around an intersection area of a gate line and a data line, a data driver that supplies a data voltage to the pixel through the data line, and the gate line. A gate driver that supplies a gate voltage to the pixel through a gate driver, a power supply that supplies a high-potential driving voltage and a low-potential driving voltage to the pixel through a driving power line, and a power supply that supplies a high-potential driving voltage and a low-potential driving voltage to the pixel through the data line based on the current flowing in the driving power line. It is characterized by comprising a control unit that controls the magnitude of the supplied data voltage.

Description

Organic light emitting display device and driving method thereof {ORGANIC LIGHT EMITTING DISPLAY DEVICE AND DRIVING METHOD FOR THE SAME}

The present invention relates to an organic light emitting display device and a driving method for compensating data voltage based on the amount of current flowing in a driving power line.

FIG. 1 is a diagram showing the current-voltage (I-V) characteristic curve of a driving transistor of an organic light emitting display device according to temperature, and FIG. 2 is a diagram showing the output of a pixel according to the same gray level value according to temperature in a conventional organic light emitting display device. This is a drawing shown accordingly.

First, referring to FIG. 1, a driving transistor within a pixel of an organic light emitting display device has different electrical characteristics depending on temperature. More specifically, due to changes in threshold voltage (Vth) depending on temperature, even if the same data voltage (Vdata) is applied to the driving transistor, the driving current (Ids) flowing through the driving transistor decreases as the temperature increases (I1->I2- >I3), and increases as the temperature decreases (I3->I2->I1).

Reflecting these characteristics, conventionally, the threshold voltage change of the driving transistor is measured, the threshold voltage change is compensated when the organic light emitting display device is turned off, and then the compensated threshold voltage is applied when the organic light emitting display device is turned on again. Accordingly, the deterioration of the driving transistor is compensated by applying the data voltage to the driving transistor.

However, the conventional compensation method determines the compensation value on the assumption that the organic light emitting display device is used at room temperature, so there is a problem in that it cannot reflect changes in the electrical characteristics of the driving transistor in a low or high temperature environment.

Accordingly, even if the deterioration of the driving transistor is compensated according to a conventional compensation method, the luminance for the same gray level value varies at high and low temperatures.

2 as an example, even if a conventional compensation method is applied to an organic light emitting display device, the driving current (Ids) of the driving transistor is lower in a high temperature environment, so the luminance for the same gray level value (16 gray) is lower than in a room temperature environment. As the driving current (Ids) of the driving transistor increases in a low-temperature environment, the luminance for the same grayscale value (16 gray) increases compared to that in a room temperature environment.

Accordingly, according to the conventional compensation method, when the organic light emitting display device is used in an environment with large temperature changes, there is a problem in that luminance deviation due to real-time temperature changes cannot be prevented.

The purpose of the present invention is to provide an organic light emitting display device and a driving method for compensating data voltage based on the amount of current flowing in a driving power line or the amount of change in current.

The objects of the present invention are not limited to the objects mentioned above, and other objects and advantages of the present invention that are not mentioned can be understood by the following description and will be more clearly understood by the examples of the present invention. Additionally, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof indicated in the patent claims.

To achieve this purpose, an organic light emitting display device according to an embodiment of the present invention includes a display panel including pixels around an intersection area of a gate line and a data line, and a data voltage that supplies a data voltage to the pixel through the data line. A driver, a gate driver for supplying a gate voltage to the pixel through the gate line, a power supply for supplying a high-potential driving voltage and a low-potential driving voltage to the pixel through a driving power line, and a current flowing in the driving power line. It is characterized in that it includes a control unit that controls the magnitude of the data voltage supplied through the data line.

In addition, a method of driving an organic light emitting display device according to an embodiment of the present invention includes detecting a current of a driving power line that supplies driving voltage to a plurality of pixels in a display panel, and responding to the detected current by referring to a memory. Determining a compensation data voltage and supplying the compensation data voltage to the plurality of pixels.

The present invention compensates for the data voltage based on the amount of current flowing in the driving power line or the amount of change in current, so that deterioration compensation for all pixels can be performed in a very simple configuration, as well as preventing luminance deviation due to real-time external temperature changes. There is an effect that can be done.

In addition to the above-described effects, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

1 is a diagram showing the current-voltage (IV) characteristic curve of a driving transistor of an organic light emitting display device according to temperature.
Figure 2 is a diagram showing the output of pixels according to the same gray level value according to temperature in a conventional organic light emitting display device.
Figure 3 is a diagram showing an organic light emitting display device according to an embodiment of the present invention.
FIG. 4 is a diagram showing the internal circuit of the pixel shown in FIG. 3.
Figures 5 and 6 are diagrams showing the control flow of an organic light emitting display device according to an embodiment of the present invention, respectively.
FIG. 7 is a diagram illustrating an example of the current detection circuit shown in FIG. 3.
Figure 8 is a diagram illustrating a method of driving an organic light emitting display device according to an embodiment of the present invention.
9 is a diagram illustrating a method of driving an organic light emitting display device according to another embodiment of the present invention.

The above-mentioned objects, features, and advantages will be described in detail later with reference to the attached drawings, so that those skilled in the art will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, identical reference numerals are used to indicate identical or similar components.

Hereinafter, the “top (or bottom)” of a component or the arrangement of any component on the “top (or bottom)” of a component means that any component is placed in contact with the top (or bottom) of the component. Additionally, it may mean that other components may be interposed between the component and any component disposed on (or under) the component.

Additionally, when a component is described as being “connected,” “coupled,” or “connected” to another component, the components may be directly connected or connected to each other, but the other component is “interposed” between each component. It should be understood that “or, each component may be “connected,” “combined,” or “connected” through other components.

The present invention relates to an organic light emitting display device and a driving method for compensating data voltage based on the amount of current flowing in a driving power line.

First, with reference to FIGS. 3 to 7 , an organic light emitting display device according to an embodiment of the present invention will be described in detail.

FIG. 3 is a diagram illustrating an organic light emitting display device according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating an internal circuit of the pixel shown in FIG. 3.

5 and 6 are diagrams showing the control flow of an organic light emitting display device according to an embodiment of the present invention, respectively. Additionally, FIG. 7 is a diagram illustrating an example of the current detection circuit shown in FIG. 3.

Referring to FIG. 3, the organic light emitting display device 1 according to an embodiment of the present invention may include a display panel 10, a gate driver 20, a data driver 30, and a control unit, and the control unit again It may include a timing controller 50 and a current detection circuit 60. The organic light emitting display device 1 shown in FIG. 3 is according to an embodiment, and its components are not limited to the embodiment shown in FIG. 3, and some components may be added, changed, or deleted as needed. You can.

Hereinafter, the control unit will be described by dividing it into the timing controller 50 and the current detection circuit 60, if necessary.

The display panel 10 may include a pixel P in each intersection area of the gate line 12 and the data line 11. As shown in FIG. 3, within the display panel 10, the gate lines 12 may be arranged side by side in the horizontal direction, and the data lines 11 may be arranged side by side in the vertical direction. At this time, the pixel P may be provided in a matrix form in an area where a plurality of gate lines GL1 to GLn and data lines DL1 to DLm intersect.

The timing controller 50 may rearrange digital video data (RGB) input from the outside to match the resolution of the display panel 10 and supply the rearranged digital video data (RGB') to the data driver 30.

In addition, the timing controller 50 controls the data driver 30 based on timing signals such as the horizontal synchronization signal (Hsync), the vertical synchronization signal (Vsync), the dot clock signal (DCLK), and the data enable signal (DE). A data control signal (DDC) for controlling the operation timing and a gate control signal (GDC) for controlling the operation timing of the gate driver 20 can be supplied.

The data driver 30 converts the rearranged digital video data (RGB') into an analog data voltage (VDATA) corresponding to the gray level value (gray) of the data (RGB') based on the data control signal (DDC). You can. Subsequently, the data driver 30 may supply the data voltage VDATA to each pixel P through a plurality of data lines DL1 to DLm.

The gate driver 20 may supply a gate voltage (VGATE, scan signal) to the pixel P through the gate line 12. More specifically, the gate driver 20 may sequentially supply the gate voltage (VGATE) to the plurality of gate lines (GL1 to GLn) based on the gate control signal (GDC).

Meanwhile, the power supply unit 40 may supply a high-potential driving voltage (EVDD) and a low-potential driving voltage (EVSS) to the pixel P through the driving power lines 13 and 14. More specifically, the power supply unit 40 can supply a high-potential driving voltage (EVDD) to the pixel P through a single high-potential driving power line 13 and a single low-potential driving power line 14. Through this, a low-potential driving voltage (EVSS) can be supplied to the pixel (P).

Although not shown in FIG. 1 , the display panel 10 may include a pair of opposing substrates bonded together and an organic light emitting device array disposed between them. Additionally, one of the pair of substrates may be a thin film transistor array substrate for supplying a driving current (Ids) to an organic light emitting device (OLED) within each pixel (P).

Referring to FIG. 4, each pixel (P) may include an organic light emitting device (OLED), a driving transistor (DT), a switching transistor (ST), and a storage capacitor (Cst).

The driving transistor (DT) is an organic light emitting device (OLED) between the high potential driving power line 13 that supplies the high potential driving voltage (EVDD) and the low potential driving power line 14 that supplies the low potential driving voltage (EVSS). ) can be connected in series.

The switching transistor ST may be disposed between the data line 11 that supplies the data voltage VDATA to each pixel P and node 1 ND1 connected to the gate electrode of the driving transistor DT. This switching transistor (ST) can be turned on according to the gate voltage (VGATE) supplied to the gate line 12 and supply the data voltage (VDATA) to node 1 (ND1).

Both ends of the storage capacitor (Cst) may be connected to node 1 (ND1) and node 2 (ND2) between the driving transistor (DT) and the organic light emitting device (OLED). This storage capacitor (Cst) can be charged by the data voltage (VDATA) supplied to node 1 (ND1) through the turned-on switching transistor (ST).

The driving transistor (DT) is turned on by the voltage charged in the storage capacitor (Cst), and the driving current (Ids) corresponding to the data voltage (VDATA) is transmitted to node 2 (ND2), that is, to the organic light emitting device (OLED). can be supplied.

According to the above-described operation, each pixel P can output light according to the grayscale value of the digital video data (RGB').

The control unit may control the size of the data voltage VDATA supplied through the data line 11 based on the current flowing in the driving power lines 13 and 14.

As shown in FIG. 3, the power supply unit 40 supplies a high-potential driving voltage (EVDD) to all pixels (P) in the display panel 10 through a single high-potential driving power line 13, and provides a single high-potential driving voltage (EVDD). A low-potential driving voltage (EVSS) can be supplied to all pixels (P) in the display panel 10 through the low-potential driving power line 14. Accordingly, the current flowing in the high-potential driving power line 13 or the low-potential driving power line 14 may be the total sum of the driving currents (Ids) of each pixel (P) shown in FIG. 4.

The control unit passes the data line 11 based on the current flowing in the high-potential driving power line 13 or the low-potential driving power line 14, that is, the total sum of the driving currents (Ids) of all pixels (P). The size of the supplied data voltage (VDATA) can be controlled.

As previously described with reference to FIGS. 1 and 2 , the driving current (Ids) of one pixel (P) for the same gray level value may vary depending on the degree of deterioration of the driving transistor (DT). In other words, the driving transistor (DT) can supply different driving currents (Ids) to the organic light emitting device (OLED) at the same data voltage (VDATA) in a high-temperature environment and a low-temperature environment.

That is, depending on the degree of deterioration of the driving transistor DT, the pixel P may output different luminance for the same gray level value, and accordingly, spots may be visible on the display panel 10 or gray level differences may occur.

To prevent this, the control unit indirectly determines the degree of deterioration of the driving transistor (DT) based on the current flowing in the driving power lines 13 and 14, and determines the size of the data voltage (VDATA) supplied to each pixel (P). By adjusting , the driving current (Ids) of the pixel (P) for the same gray level value can be controlled to be constant.

In one example, when the organic light emitting display device 1 is placed in a high temperature environment and the driving transistor DT is partially deteriorated, the size of the driving current Ids of each pixel P may decrease, and accordingly the driving power line The current flowing through (13, 14) can also be reduced.

The control unit may detect a decrease in the amount of current flowing through the driving power lines 13 and 14, and increase the size of the data voltage VDATA applied to each pixel P to compensate for this.

In another example, when the organic light emitting display device 1 is placed in a low temperature environment, the size of the driving current (Ids) of each pixel (P) may increase and the current flowing in the driving power lines 13 and 14 may also increase accordingly. It can increase.

The control unit may detect an increase in the amount of current flowing through the driving power lines 13 and 14, and reduce the size of the data voltage VDATA applied to each pixel P to compensate for this increase.

That is, the control unit can adjust the size of the data voltage VDATA in inverse proportion to the amount of current flowing through the driving power lines 13 and 14.

More specifically, the control unit detects the current flowing in the driving power lines 13 and 14, identifies the compensation data voltage (VDATA') corresponding to the detected current, and applies the compensation data voltage (VDATA') to each pixel (P). ) can be controlled to supply the data driver 30.

For the current detection operation, the control unit may include a current detection circuit 60 that detects the current flowing in the driving power lines 13 and 14.

The current detection circuit 60 may include any circuit that measures the current flowing in the high-potential driving power line 13 or the low-potential driving power line 14. The current detection circuit 60 can convert the current value flowing through the driving power lines 13 and 14 into digital data and provide it to the timing controller 50.

Referring to FIG. 7, in one example, the current detection circuit 60 includes a shunt resistor (Rs) provided between each node to which a high potential driving voltage (EVDD) and a low potential driving voltage (EVSS) are applied, and a shunt resistor ( It may include an analog-to-digital converter (ADC) connected to both ends of Rs) that detects the current flowing in the driving power lines 13 and 14, converts the magnitude of the detected current into a digital signal, and outputs it.

As shown in FIG. 3, a load including the display panel 10 may be formed between the high potential driving voltage (EVDD) and the low potential driving voltage (EVSS). Current may flow from a node to which a high-potential driving voltage (EVDD) is applied to a node to which a low-potential driving voltage (EVSS) is applied, and a shunt resistor (Rs) may be provided on the current path.

The analog-to-digital converter (ADC) detects the magnitude of the voltage applied to both ends of the shunt resistor (Rs), and uses the magnitude of the detected voltage and the resistance value of the shunt resistor (Rs) to connect the driving power lines (13, 14). The size of the current flowing through can be identified. Subsequently, the analog-to-digital converter (ADC) can convert the size of the identified current into a digital signal and output it to the timing controller 50.

In one example, timing controller 50 may identify a compensation data voltage (VDATA') corresponding to a current value provided from current detection circuit 60.

Here, the compensation data voltage VDATA' may be a data voltage VDATA for equalizing the driving current Ids of the driving transistor DT with respect to the grayscale value of one digital video data RGB. This compensation data voltage VDATA' may be predetermined to correspond to the current value (total sum of driving currents Ids) flowing in the driving power lines 13 and 14.

Referring to FIG. 5, the timing controller 50 may include a processor 50a and a memory 50b. The processor 50a may receive current values (hereinafter referred to as driving power currents, IEVDD) flowing through the driving power lines 13 and 14 from the current detection circuit 60.

Subsequently, the processor 50a may refer to the memory 50b to identify the compensation data voltage VDATA' corresponding to the driving power current IEVDD. To this end, a look-up table (LUT) in which the size of the driving power current (IEVDD) and the compensation data voltage (VDATA') are matched one-to-one in advance may be stored in the memory 50b.

More specifically, the processor 50a may identify the compensation data voltage VDATA' corresponding to the driving power current IEVDD for each gray level value. In other words, when arbitrary digital video data (RGB) is input, the processor 50a identifies the compensation data voltage (VDATA') for each digital video data (RGB) based on the driving power current (IEVDD). You can.

For example, the driving power current (IEVDD) for each grayscale value of 0 to 255 and the compensation data voltage (VDATA') corresponding to the driving power current (IEVDD) may be stored in advance in the memory 50b. More specifically, the memory 50b contains the relationship between the driving power current (IEVDD) and the compensation data voltage (VDATA') for 0 gray, and the relationship between the driving power current (IEVDD) and the compensation data voltage (VDATA') for 1 gray. , The relationship between the driving power current (IEVDD) and compensation data voltage (VDATA') for 2 gray, ??, The relationship between the driving power current (IEVDD) and compensation data voltage (VDATA') for 255 gray can be stored in advance. there is.

As shown in FIG. 5, the processor 50a can receive digital video data (RGB) from the outside and identify the grayscale value of the data. Additionally, the processor 50a may receive the driving power current IEVDD from the current detection circuit 60.

Next, the processor 50a refers to the memory 50b, checks a lookup table for the identified grayscale value, and identifies the compensation data voltage VDATA' corresponding to the driving power current IEVDD by referring to the lookup table. can do.

When the compensation data voltage VDATA' is identified, the processor 50a may control the data driver 30 to supply the compensation data voltage VDATA' to the pixel P.

More specifically, the processor 50a may generate digital video data (RGB') corresponding to the compensation data voltage (VDATA') and provide it to the data driver 30, and the data driver 30 may generate the digital video data (RGB') corresponding to the compensation data voltage (VDATA'). (RGB') can be converted into an analog data voltage (VDATA') and supplied to each pixel (P).

Accordingly, regardless of whether the driving transistor DT is deteriorated, all pixels P can output luminance according to digital video data (RGB) input from the outside.

For example, when the driving power current (IEVDD) decreases, the processor 50a may identify a voltage higher than the data voltage (VDATA) currently being supplied to the pixel (P) as the compensation data voltage (VDATA'), and the data driver ( 30) supplies the compensation data voltage VDATA' to each pixel P, thereby compensating for a decrease in luminance due to changes in external temperature.

On the other hand, when the driving power current (IEVDD) increases, the processor 50a can identify a voltage lower than the data voltage (VDATA) currently being supplied to the pixel (P) as the compensation data voltage (VDATA'), and the data driver ( 30) supplies the compensation data voltage VDATA' to each pixel P, thereby compensating for an increase in luminance due to a change in external temperature.

In another example, the timing controller 50 identifies the current change amount (△I) with respect to the reference current based on the driving power current (IEVDD), and the data voltage change amount (△VDATA) corresponding to the identified current change amount (△I). ) can be identified.

Referring to FIG. 6, the timing controller 50 may include a data alignment unit 50c, a data compensation unit 50d, and a memory 50b. The data alignment unit 50c may rearrange digital video data (RGB) input from the outside to match the resolution of the display panel 10 and output the rearranged digital video data (RGB').

Meanwhile, the data compensation unit 50d may receive the driving power current (IEVDD) from the current detection circuit 60. Subsequently, the data compensation unit 50d can identify the amount of current change (ΔI) by comparing the driving power current (IEVDD) and the reference current.

Here, the reference current can be defined as the driving power current (IEVDD) in a normal state. The normal state may be determined according to temperature, and for example, the normal state may be when the organic light emitting display device 1 is placed at room temperature (25oC). This reference current can be stored in advance in the memory 50b.

The reference current may be the driving power current (IEVDD) for an arbitrary gray level value in a normal state. For example, if the gray level values are divided into 256, the reference current may also be predetermined to be 256.

Accordingly, the memory 50b may store the reference current for 0 gray, the reference current for 1 gray, the reference current for 2 gray, and the reference current for ?? and 255 gray, respectively.

The data compensation unit 50d can identify the grayscale value of digital video data (RGB) input from the outside, and identify a reference current for the corresponding grayscale value by referring to the memory 50b. Subsequently, the data compensation unit 50d may identify the current change amount ΔI, which is the difference between the driving power current IEVDD provided from the current detection circuit 60 and the identified reference current.

When the current change amount (△I) is identified, the processor 50a may refer to the memory 50b to identify the data voltage change amount (△VDATA) corresponding to the current change amount (△I). For this purpose, a lookup table in which the amount of current change (△I) and the amount of data voltage change (△VDATA) are matched one-to-one in advance may be stored in the memory 50b.

More specifically, the processor 50a may identify the data voltage change amount (ΔVDATA) corresponding to the current change amount (ΔI) for each gray level value. In other words, when arbitrary digital video data (RGB) is input, the processor 50a identifies the data voltage change amount (△VDATA) for each digital video data (RGB) based on the current change amount (△I). You can.

For example, the memory 50b may store in advance the current change amount (△I) for each grayscale value of 0 to 255 and the data voltage change amount (△VDATA) corresponding to the current change amount (△I). More specifically, the memory 50b contains the relationship between the current change amount (△I) and the data voltage change amount (△VDATA) for 0 gray, and the relationship between the current change amount (△I) and the data voltage change amount (△VDATA) for 1 gray. , 2 The relationship between the current change amount (△I) and the data voltage change amount (△VDATA) for gray, ??, The relationship between the current change amount (△I) and the data voltage change amount (△VDATA) for 255 gray can be stored in advance. there is.

As shown in FIG. 6, the data compensator 50d can receive digital video data (RGB) from the outside and identify the grayscale value of the data. Additionally, as described above, the data compensation unit 50d can identify the amount of current change (ΔI).

The data compensator 50d may refer to the memory 50b to check a lookup table for grayscale values and identify the data voltage change amount (△VDATA) corresponding to the current change amount (△I) by referring to the lookup table. .

When the data voltage change amount (△VDATA) is identified, the data compensation unit 50d controls the data driver 30 to supply the compensation data voltage (VDATA') reflecting the data voltage change amount (△VDATA) to the pixel P. You can.

More specifically, the data compensation unit 50d generates a compensation value (RGBc) of digital video data corresponding to the data voltage change amount (△VDATA), and outputs a compensation value (RGBc) of digital video data to the output terminal of the data alignment unit 50c. RGBc) can be output. Accordingly, the compensated digital video data (RGB'') is the sum of the digital video data (RGB') sorted by the data alignment unit (50c) and the compensation value (RGBc) of the digital video data generated by the data compensator (50d). ) may be provided to the data driver 30.

The data driver 30 may convert the compensated digital video data (RGB'') into an analog data voltage (VDATA') and supply it to each pixel (P).

Accordingly, regardless of whether the driving transistor DT is deteriorated, all pixels P can output luminance according to digital video data (RGB) input from the outside.

For example, when the driving power current (IEVDD) is lowered and the current change amount (△I) is identified as a negative value, the data compensation unit 50d can identify the data voltage change amount (△VDATA) as a positive value, and the data driver ( 30) compensates for the decrease in luminance due to changes in external temperature by supplying a compensation data voltage (VDATA') to each pixel (P) that reflects the positive data voltage change (△VDATA) in the currently supplied data voltage (VDATA). can do.

On the other hand, when the driving power current (IEVDD) increases and the current change amount (△I) is identified as a positive value, the data compensation unit 50d can identify the data voltage change amount (△VDATA) as a negative value, and the data driver ( 30) compensates for the increase in luminance due to changes in external temperature by supplying a compensation data voltage (VDATA') to each pixel (P) that reflects the negative data voltage change (△VDATA) in the currently supplied data voltage (VDATA). can do.

Hereinafter, the driving method of the organic light emitting display device of the present invention will be described in detail with reference to FIGS. 8 and 9.

FIG. 8 is a diagram illustrating a method of driving an organic light emitting display device according to an embodiment of the present invention, and FIG. 9 is a diagram illustrating a method of driving an organic light emitting display device according to another embodiment of the present invention.

The method of driving an organic light emitting display device of the present invention can be applied to the organic light emitting display device 1 described with reference to FIGS. 3 and 4 and can be performed by a driving module. Here, the driving module may include the timing controller 50, data driver 30, gate driver 20, and current detection circuit 60 shown in FIG. 3. Since each component constituting the driving module has been described above, detailed description will be omitted here.

The driving module can detect the current of the driving power lines 13 and 14 that supply driving voltages (EVDD and EVSS) to the plurality of pixels (P) in the display panel 10.

3 shows a method of supplying driving power (EVDD, EVSS) to the display panel 10, a plurality of pixels (P) in the display panel 10, and each pixel (P) through the driving power lines 13 and 14. Since it has been described with reference to , detailed description will be omitted below.

When the current of the driving power lines 13 and 14 is detected, the driving module may refer to the memory and determine the compensation data voltage VDATA' corresponding to the previously detected current.

In one example, referring to FIG. 8, the driving module may detect the current of the driving power lines 13 and 14 (S11) and then refer to the memory to identify the data voltage VDATA' corresponding to the detected current. Yes (S12)

In the memory of the driving module, the relationship between the data voltage and the current of the driving power lines 13 and 14 for any gray level value may be stored in advance in the form of a lookup table. Accordingly, the driving module can identify the data voltage VDATA' corresponding to the current of the driving power lines 13 and 14 by referring to the memory.

More specifically, the driving module identifies the grayscale value of digital video data (RGB) input from the outside, checks the lookup table for the corresponding grayscale value by referring to the memory, and determines the grayscale value of the identified driving power lines 13 and 14. The data voltage (VDATA') corresponding to the current can be identified.

The driving module may determine the identified data voltage VDATA' as the compensation data voltage VDATA' and drive the pixel P according to the determined compensation data voltage VDATA' (S13).

More specifically, the driving module may supply the driving current (Ids) to the organic light emitting device (OLED) by applying the compensation data voltage (VDATA') to the gate terminal of the driving transistor (DT) provided in the pixel (P).

Since the driving current Ids is determined according to the size of the compensation data voltage VDATA', the pixel P can output luminance according to the compensation data voltage VDATA'.

In another example, referring to FIG. 9, the driving module may identify the amount of current change (ΔI) with respect to the reference current based on the current of the driving power lines 13 and 14 (S21). Since the method of identifying the amount of current change (△I) by comparing the detected current of the driving power lines 13 and 14 with the reference current has been described above, detailed description will be omitted here.

In the memory of the driving module, the relationship between the data voltage change amount (ΔVDATA) and the current change amount (ΔI) for an arbitrary gray level value may be stored in advance in the form of a lookup table. Accordingly, the driving module can refer to the memory and identify the data voltage change amount (△VDATA) corresponding to the current change amount (△I) (S22).

More specifically, the driving module identifies the grayscale value of the digital video data (RGB) input from the outside, checks the lookup table for the corresponding grayscale value by referring to the memory, and generates a value corresponding to the identified current change amount (△I). The data voltage change amount (△VDATA) can be identified.

The driving module may determine the compensation data voltage (VDATA') by reflecting the identified data voltage change (△VDATA) in the data voltage (VDATA) supplied to the pixel (P), and determine the compensation data voltage (VDATA') by reflecting the identified data voltage change (△VDATA). Accordingly, the pixel (P) can be driven (S23).

More specifically, the driving module may determine the compensation data voltage (VDATA') by adding or subtracting the data voltage change (△VDATA) from the data voltage (VDATA) currently being supplied to the pixel (P), and the determined compensation data voltage (VDATA). ') can be applied to the gate terminal of the driving transistor (DT) provided in the pixel (P) to supply the driving current (Ids) to the organic light emitting device (OLED).

Since the driving current Ids is determined according to the size of the compensation data voltage VDATA', the pixel P can output luminance according to the compensation data voltage VDATA'.

As described above, the present invention not only allows deterioration compensation for all pixels to be performed in a very simple configuration by compensating the data voltage based on the amount of current or change in current flowing in the driving power line, but also compensates for real-time external temperature changes. It is possible to prevent luminance deviation.

The above-described present invention may be subject to various substitutions, modifications, and changes without departing from the technical spirit of the present invention to those skilled in the art to which the present invention pertains. It is not limited by .

Claims (11)

A display panel including pixels around an intersection area of a gate line and a data line;
a data driver that supplies a data voltage to the pixel through the data line;
a gate driver that supplies a gate voltage to the pixel through the gate line;
a power supply unit that supplies a high-potential driving voltage and a low-potential driving voltage to the pixel through a driving power line; and
It includes a current detection circuit that detects the current flowing in the driving power line, and a control unit that controls the magnitude of the data voltage supplied through the data line based on the current flowing in the driving power line,
The current detection circuit is connected to a shunt resistor provided between each node to which the high-potential driving voltage and the low-potential driving voltage are applied, and both ends of the shunt resistor to detect a current flowing in the driving power line, and the detection Including an analog-to-digital converter that converts the magnitude of the current into a digital signal and outputs it,
Organic light emitting display device.
According to paragraph 1,
The control unit
An organic light emitting display device that detects a current flowing in the driving power line, identifies a compensation data voltage corresponding to the detected current, and controls the data driver to supply the identified compensation data voltage to the pixel.
According to paragraph 2,
The control unit
An organic light emitting display device that identifies the compensation data voltage corresponding to the current flowing in the driving power line for each gray level value.
According to paragraph 1,
The control unit
Identify the amount of current change with respect to the reference current based on the current flowing in the driving power line, identify the amount of data voltage change corresponding to the identified amount of current change, and supply a compensation data voltage reflecting the amount of data voltage change to the pixel. An organic light emitting display device that controls the data driver.
According to paragraph 4,
The control unit
An organic light emitting display device that identifies the data voltage change amount corresponding to the current change amount for each gray level value.
According to paragraph 4,
The reference current is
An organic light emitting display device in which the current flows in the driving power line for an arbitrary gray level value in a normal state.
delete delete A driving method comprising the organic light emitting display device of claim 1,
detecting a current of the driving power line that supplies driving voltage to a plurality of pixels in the display panel;
determining a compensation data voltage corresponding to the detected current by referring to a memory; and
Comprising the step of supplying the compensation data voltage to the plurality of pixels.
Method of driving an organic light emitting display device.
According to clause 9,
The step of determining a compensation data voltage corresponding to the detected current by referring to the memory
identifying a data voltage corresponding to the detected current by referring to the memory; and
Comprising determining the identified data voltage as the compensation data voltage.
Method of driving an organic light emitting display device.
According to clause 9,
The step of determining a data voltage corresponding to the detected current by referring to the memory
Identifying the amount of current change with respect to the reference current based on the detected current;
identifying a data voltage change amount corresponding to the identified current change amount by referring to the memory; and
And determining the compensation data voltage by reflecting the amount of data voltage change in the data voltage supplied to the pixel.
Method of driving an organic light emitting display device.

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