KR20200039931A - 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 for compensating a data voltage based on amount of a current flowing in a driving power line, and a driving method thereof. According to one embodiment of the present invention, the organic light emitting display device comprises: a display panel having a pixel around a cross region of a gate line and a data line; a data driving unit supplying a data voltage to the pixel through the data line; a gate driving unit supplying a gate voltage to the pixel through the gate line; a power supply unit supplying a high potential driving voltage and a low potential driving voltage to the pixel through the driving power line; and a control unit controlling magnitude of the data voltage supplied through the data line based on a current flowing in the driving power line.

Description

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

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

1 is a diagram showing a current-voltage (IV) characteristic curve of a driving transistor of an organic light emitting display device according to temperature, and FIG. 2 is a conventional organic light emitting display device, in which a pixel output according to the same gradation value is applied to temperature. It is a drawing shown accordingly.

First, referring to FIG. 1, a driving transistor in a pixel of an organic light emitting display device has different electrical characteristics according to temperature. More specifically, due to a change in the threshold voltage Vth according to 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 (I3-> I2-> I1) as the temperature decreases.

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

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

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

Referring to FIG. 2 as an example, even if the conventional compensation method is applied to the organic light emitting display device, the driving current Ids of the driving transistor is lowered in a high temperature environment, so the luminance for the same gradation value (16 gray) is higher than in a normal temperature environment. The driving current (Ids) of the driving transistor is lowered in a low temperature environment, so the luminance for the same gray scale value (16 gray) is increased than in a normal temperature environment.

Accordingly, according to the conventional compensation method, when the organic light emitting display device is used in an environment in which the temperature change is large, there is a problem in that it is impossible to prevent the luminance deviation due to the real-time temperature change.

An object of the present invention is to provide an organic light emitting display device and a driving method for compensating for a data voltage based on an amount of current flowing in a driving power line or a 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 not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. In addition, it will be readily appreciated that the objects and advantages of the present invention can be realized by means of the appended claims and combinations thereof.

An organic light emitting display device according to an exemplary embodiment of the present invention for achieving the above object is a display panel having pixels around a crossing region between a gate line and a data line, and data supplying a data voltage to the pixel through the data line A driving unit, a gate driving unit supplying a gate voltage to the pixel through the gate line, a power supply unit supplying a high potential driving voltage and a low potential driving voltage to the pixel through the driving power line, and a current flowing through the driving power line It characterized in that it comprises a control unit for controlling the magnitude of the data voltage supplied through the data line.

In addition, the driving method of the organic light emitting display device according to an exemplary embodiment of the present invention includes detecting a current of a driving power supply line that supplies a driving voltage to a plurality of pixels in a display panel and corresponds to the detected current by referring to a memory It characterized in that it comprises the step of determining the compensation data voltage and supplying the compensation data voltage to the plurality of pixels.

The present invention can compensate for deterioration for all pixels in a very simple configuration by compensating for the data voltage based on the amount of current flowing in the driving power line or the amount of current change, 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, the concrete effects of the present invention will be described together while describing the specific matters for carrying out the invention.

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

The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, and accordingly, a person skilled in the art to which the present invention pertains can easily implement the technical spirit of the present invention. In describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

In the following, the arrangement of any component in the "upper (or lower)" or "upper (or lower)" of the component means that any component is disposed in contact with the upper surface (or lower surface) of the component. In addition, it may mean that other components may be interposed between the component and any component disposed on (or under) the component.

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

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

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

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

5 and 6 are views illustrating a control flow of an organic light emitting display device according to an embodiment of the present invention, respectively. 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 exemplary 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 A timing controller 50 and a current detection circuit 60 may be included. 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 necessary You can.

In the following, the controller is divided into a timing controller 50 and a current detection circuit 60 as necessary to be described.

The display panel 10 may include pixels P for each intersection area of the gate line 12 and the data line 11. 3, in 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. In this case, the pixel P may be provided in a matrix form in an area where the plurality of gate lines GL1 to GLn and the data lines DL1 to DLm intersect.

The timing controller 50 may rearrange the digital video data RGB input from the outside according to 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 is based on timing signals such as a horizontal synchronization signal (Hsync), a vertical synchronization signal (Vsync), a dot clock signal (DCLK), and a 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 may be supplied.

The data driver 30 converts the rearranged digital video data RGB 'into an analog data voltage VDATA corresponding to a gray level value of the corresponding 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 the 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 the high potential driving voltage EVDD and the low potential driving voltage EVSS to the pixel P through the driving power lines 13 and 14. More specifically, the power supply unit 40 may 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 supply line 14 may be provided. Through this, the low potential driving voltage EVSS may be supplied to the pixel P.

Although not illustrated in FIG. 1, the display panel 10 may include a pair of substrates that are opposed to each other and an organic light emitting diode array disposed therebetween. Further, any one of the pair of substrates may be a thin film transistor array substrate for supplying driving currents Ids to the organic light emitting diodes OLED in 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 supply line 13 that supplies the high potential driving voltage EVDD and the low potential driving power supply line 14 that supplies the low potential driving voltage EVSS. ) 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 the node 1 ND1 connected to the gate electrode of the driving transistor DT. The switching transistor ST is turned on according to the gate voltage VGATE supplied to the gate line 12 to supply the data voltage VDATA to the node 1 ND1.

Both ends of the storage capacitor Cst may be connected to the node 1 ND1 and the node 2 ND2 between the driving transistor DT and the organic light emitting diode OLED. The storage capacitor Cst may be charged by the data voltage VDATA supplied to the 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 transferred to the node 2 ND2, that is, the organic light emitting diode OLED. Can supply.

According to the above-described operation, each pixel P may output light according to a gradation value of 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 through 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 a single The low potential driving voltage EVSS may be supplied to all the 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 supply line 13 or the low potential driving power supply line 14 may be the total sum of the driving currents Ids of each pixel P illustrated in FIG. 4.

The controller controls the current through the high potential driving power line 13 or the low potential driving power line 14, that is, through the data line 11 based on the sum of the driving currents Ids of all the pixels P. The size of the supplied data voltage VDATA can be controlled.

As described above with reference to FIGS. 1 and 2, the driving current Ids of one pixel P for the same gradation value may be different depending on the degree of deterioration of the driving transistor DT. In other words, in the high temperature environment and the low temperature environment, the driving transistor DT may supply different driving currents Ids to the organic light emitting diode OLED at the same data voltage VDATA.

That is, the pixels P may output different luminance for the same gradation value according to the degree of deterioration of the driving transistor DT, and accordingly, unevenness in the display panel 10 or a gradation level difference may occur.

To prevent this, the controller indirectly grasps the degree of deterioration of the driving transistor DT based on the current flowing through the driving power lines 13 and 14, and the magnitude of the data voltage VDATA supplied to each pixel P By adjusting, it is possible to control the driving current Ids of the pixels P for the same gradation value constant.

In one example, when the organic light emitting diode display 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) may also decrease.

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 accordingly, the current flowing through the driving power lines 13 and 14 also Can increase.

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

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

More specifically, the controller detects the current flowing through the driving power lines 13 and 14, identifies the compensation data voltage VDATA 'corresponding to the detected current, and compensates the data voltage VDATA' for each pixel P. ), The data driver 30 can be controlled.

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 supply line 13 or the low potential driving power supply line 14. The current detection circuit 60 may 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 and a shunt resistor (Rs) provided between each node to which the high potential driving voltage (EVDD) and the low potential driving voltage (EVSS) are applied. It may include an analog-to-digital converter (ADC) that is connected to both ends of Rs) to detect the current flowing through the driving power lines 13 and 14, and converts and outputs the magnitude of the detected current into a digital signal.

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. The current may flow from a node to which the high potential driving voltage EVDD is applied to a node to which the 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 drive power lines (13, 14). The magnitude of the current flowing through it can be identified. Subsequently, the analog-to-digital converter ADC converts the magnitude of the identified current into a digital signal and outputs it to the timing controller 50.

In one example, the timing controller 50 may identify the compensation data voltage VDATA 'corresponding to the current value provided from the 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 gradation value of one digital video data RGB. The compensation data voltage VDATA 'may be determined in advance to correspond to a current value (total sum of driving currents Ids) flowing through 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 be provided with a current value (hereinafter, a driving power current, IEVDD) flowing through the driving power lines 13 and 14 from the current detecting circuit 60.

Subsequently, the processor 50a may identify the compensation data voltage VDATA 'corresponding to the driving power current IEVDD with reference to the memory 50b. 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 may be previously stored in the memory 50b.

More specifically, the processor 50a may identify, for each gradation value, the compensation data voltage VDATA 'corresponding to the driving power current IEVDD. In other words, when the 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 the memory 50b in advance. More specifically, the relationship between the driving power current (IEVDD) for 0 gray and the compensation data voltage (VDATA ') in the memory 50b, and the relationship between the driving power current (IEVDD) and compensation data voltage (VDATA') for 1 gray. , 2 The relationship between the driving power current (IEVDD) and the compensation data voltage (VDATA ') for gray,?, The relationship between the driving power current (IEVDD) and compensation data voltage (VDATA') for 255 gray can be stored in advance. .

As shown in FIG. 5, the processor 50a may receive digital video data RGB from the outside and identify grayscale values of the corresponding data. In addition, the processor 50a may be provided with a driving power current (IEVDD) from the current detection circuit 60.

Subsequently, 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 with reference to the lookup table. can do.

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

More specifically, the processor 50a may generate and provide digital video data RGB 'corresponding to the compensation data voltage VDATA' to the data driving unit 30, and the data driving unit 30 may generate corresponding digital video data. (RGB ') may 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 the 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, 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) by supplying the compensation data voltage (VDATA ') to each pixel (P), it is possible to compensate for the luminance drop due to the external temperature change.

On the other hand, when the driving power current IEVDD increases, the processor 50a may 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) by supplying the compensation data voltage (VDATA ') to each pixel (P), it is possible to compensate for the increase in luminance due to the change in the external temperature.

In another example, the timing controller 50 identifies the current change amount ΔI with respect to the reference current based on the driving power current IEVDD, and the data voltage change amount ΔVDATA corresponding to the identified current change amount ΔI ) 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 rearranges the digital video data RGB input from the outside according to the resolution of the display panel 10 and outputs the rearranged digital video data RGB '.

Meanwhile, the data compensation unit 50d may be provided with a driving power current (IEVDD) from the current detection circuit 60. Subsequently, the data compensator 50d may identify the current change amount ΔI by comparing the driving power current IEVDD and the reference current.

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

The reference current may be a driving power current (IEVDD) for any one gradation value in a steady state. For example, when the gradation value is divided into 256, the reference current may also be determined in advance to 256.

Accordingly, a reference current for 0 gray, a reference current for 1 gray, a reference current for 2 gray, and a reference current for?, 255 gray may be stored in the memory 50b, respectively.

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

When the current change amount ΔI is identified, the processor 50a may refer to the memory 50b to identify the data voltage change amount ΔVDATA corresponding to the current change amount ΔI. To this end, a lookup table in which the current change amount ΔI and the data voltage change amount ΔVDATA match one-to-one may be previously 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 gradation value. In other words, when the arbitrary digital video data RGB is input, the processor 50a identifies the data voltage change amount ΔVDATA for each digital video data RGB based on the current change amount ΔI. You can.

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

As illustrated in FIG. 6, the data compensation unit 50d may receive digital video data RGB from the outside and identify grayscale values of the corresponding data. In addition, as described above, the data compensator 50d may identify the current change amount ΔI.

The data compensator 50d may check the lookup table for the gradation value with reference to the memory 50b, and identify the data voltage change amount ΔVDATA corresponding to the current change amount ΔI with reference to the lookup table. .

When the data voltage change amount ΔVDATA is identified, the data compensation unit 50d controls the data driving unit 30 to supply the compensation data voltage VDATA ′ reflecting the data voltage change amount ΔVDATA 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 amount of change in the data voltage (ΔVDATA), and compensates the digital video data at the output terminal of the data alignment unit 50c ( RGBc) can be output. Accordingly, the compensated digital video data RGB which the digital video data RGB 'aligned by the data alignment unit 50c and the compensation value RGBc of the digital video data generated by the data compensation unit 50d are combined. ) 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 the 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 ΔI is identified as a negative value, the data compensator 50d can identify the data voltage change amount ΔVDATA as a positive value, and the data driver ( 30) compensates for the luminance drop due to the external temperature change by supplying the compensation data voltage (VDATA ') in which the positive data voltage change amount (ΔVDATA) is reflected to the data voltage (VDATA) currently being supplied to each pixel (P). can do.

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

Hereinafter, a 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.

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

The method of driving the 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 may be performed by a driving module. Here, the driving module may include a timing controller 50 illustrated in FIG. 3, a data driving unit 30, a gate driving unit 20, and a current detection circuit 60. Since each configuration constituting the driving module has been described above, a detailed description thereof will be omitted.

The driving module may detect currents 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 illustrates a method of supplying driving power (EVDD, EVSS) to each pixel P through the display panel 10, the plurality of pixels P in the display panel 10, and 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 to determine the compensation data voltage VDATA 'corresponding to the previously detected current.

In an example, referring to FIG. 8, the driving module detects the current of the driving power lines 13 and 14 (S11) and then refers 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 of the data voltage with respect to the current of the driving power lines 13 and 14 for an arbitrary gradation value may be previously stored in the form of a look-up table. Accordingly, the driving module may identify the data voltage VDATA 'corresponding to the current of the driving power lines 13 and 14 with reference to the memory.

More specifically, the driving module identifies the gradation value of the digital video data (RGB) input from the outside, and checks a lookup table for the gradation value with reference to the memory, thereby identifying 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 may 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 diode 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 current change amount ΔI with respect to the reference current based on the current of the driving power lines 13 and 14 (S21). A method of identifying the current change amount ΔI by comparing the detected currents of the driving power lines 13 and 14 with the reference current has been described above, so a detailed description thereof will be omitted here.

In the memory of the driving module, a relationship of a data voltage change amount ΔVDATA with respect to a current change amount ΔI with respect to an arbitrary gradation value may be previously stored in the form of a look-up table. Accordingly, the driving module may identify the data voltage change amount ΔVDATA corresponding to the current change amount ΔI with reference to the memory (S22).

More specifically, the driving module identifies a gradation value of digital video data (RGB) input from the outside, checks a lookup table for the gradation value with reference to the memory, and corresponds to the identified current change amount (ΔI) The data voltage change amount (ΔVDATA) can be identified.

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

More specifically, the driving module may determine the compensation data voltage VDATA 'by adding or subtracting the data voltage change amount ΔVDATA to the data voltage VDATA currently being supplied to the pixel P, and the determined compensation data voltage VDATA. ') May be applied to the gate terminal of the driving transistor DT provided in the pixel P to supply the driving current Ids to the 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 can compensate for deterioration for all pixels in a very simple configuration by compensating for the data voltage based on the amount of current flowing in the driving power line or the amount of current change, as well as real-time external temperature change. The luminance deviation can be prevented.

The above-described invention, the above-described embodiments and the accompanying drawings because it is possible for a person having ordinary skill in the art to which the present invention pertains, various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It is not limited by.

Claims (11)

A display panel having pixels around an intersection region of the gate line and the data line;
A data driver supplying a data voltage to the pixel through the data line;
A gate driver supplying a gate voltage to the pixel through the gate line;
A power supply unit supplying a high potential driving voltage and a low potential driving voltage to the pixel through a driving power line; And
And a control unit controlling the magnitude of the data voltage supplied through the data line based on the current flowing in the driving power line.
Organic light emitting display device.
According to claim 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 so that the identified compensation data voltage is supplied to the pixel.
According to claim 2,
The control unit
For each gradation value, the organic light emitting display device for identifying the compensation data voltage corresponding to the current flowing in the driving power line.
According to claim 1,
The control unit
Based on the current flowing through the driving power line, a current change amount for a reference current is identified, a data voltage change amount corresponding to the identified current change amount is identified, and a compensation data voltage reflecting the data voltage change amount is supplied to the pixel. An organic light emitting display device for controlling the data driver.
According to claim 4,
The control unit
For each gradation value, an organic light emitting display device that identifies the amount of change in the data voltage corresponding to the amount of change in current.
According to claim 4,
The reference current
An organic light emitting display device that is a current flowing in the driving power line for a certain grayscale value in a normal state.
According to claim 1,
The control unit
And a current detection circuit that detects a current flowing in the driving power line.
The method of claim 7,
The current detection circuit
A shunt resistor provided between each node to which the high potential driving voltage and the low potential driving voltage are applied,
And an analog-to-digital converter connected to both ends of the shunt resistor to detect a current flowing in the driving power line, and convert the magnitude of the detected current into a digital signal for output.
Organic light emitting display device.
Detecting a current of a driving power line supplying driving voltages to a plurality of pixels in the display panel;
Determining a compensation data voltage corresponding to the detected current with reference to a memory; And
And supplying the compensation data voltage to the plurality of pixels.
Method for driving organic light emitting display device.
The method of claim 9,
Determining the compensation data voltage corresponding to the detected current with reference to the memory is
Identifying a data voltage corresponding to the detected current with reference to the memory; And
And determining the identified data voltage as the compensation data voltage.
Method for driving organic light emitting display device.
The method of claim 9,
Determining the data voltage corresponding to the detected current with reference to the memory is
Identifying a current change amount with respect to a reference current based on the detected current;
Identifying a data voltage change amount corresponding to the identified current change amount with reference to the memory; And
And determining the compensation data voltage by reflecting the variation of the data voltage in the data voltage supplied to the pixel.
Method for driving organic light emitting display device.

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