KR20170050749A - Organic light-emitting display device, and compensation method of organic light-emitting display device - Google Patents

Abstract

The present embodiments relate to a compensation technique of an organic light emitting display device, and more specifically, to an organic light emitting display device and a compensation method thereof. The organic light emitting display device calculates the n^th degree of a mobility compensation value from the n^th degree of a mobility sensitivity value, generates and outputs (n + 1)^th degree-of-mobility sensing data to the (n + 1)^th degree-of-mobility sensing section based on the calculated n^th mobility compensation value so that the (n + 1)^th degree-of-mobility sensing data sensed in the (n + 1)^th degree-of-mobility sensing section has a particular ratio depending on the characteristics of the mobility; and calculates the (n + 1)^th mobility compensation value from the (n + 1)^th mobility sensing value. So, mobility compensation can be performed more accurately.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting display device and an organic light emitting display device having the organic light emitting display device,

The present embodiments relate to a compensation technique of an organic light emitting display for displaying an image.

2. Description of the Related Art [0002] In recent years, an organic light emitting diode (OLED) display device that has been spotlighted as a display device has advantages of high response speed, high luminous efficiency, high luminance and wide viewing angle by using an organic light emitting diode (OLED)

Such an organic light emitting display device arranges subpixels including organic light emitting diodes in a matrix form and controls the brightness of subpixels selected by the scan signals according to the gradation of data.

Each sub-pixel of the organic light emitting diode display may include an organic light emitting diode and a driving transistor for driving the organic light emitting diode.

On the other hand, the driving transistors in each sub-pixel have inherent characteristic values such as threshold voltage and mobility. The inherent characteristic values of each of the driving transistors can be changed by the progress of the degradation according to the driving time.

For this reason, a difference in the degree of deterioration between the driving transistors occurs due to the difference in driving time between the driving transistors in each sub-pixel, and a characteristic value deviation between the driving transistors may also occur.

Such a characteristic value deviation between the driving transistors may cause a luminance deviation between the subpixels, which may be a main factor causing image quality degradation.

Accordingly, various techniques have been developed to compensate for variations in characteristic values between driving transistors.

Nevertheless, the problem that the characteristic value sensing that is necessarily required to compensate for the characteristic value deviation between the driving transistors can not be precisely solved still remains.

In particular, the sensing of the mobility, which means the current capability of the driving transistor, suffers from considerable difficulty in accurately performing due to various factors.

It is an object of the present embodiments to provide an organic light emitting display device and a compensation method thereof that can more accurately compensate mobility.

Another object of the present embodiments is to provide an organic light emitting display device and a compensation method thereof capable of suppressing both luminance variation due to initial mobility characteristic variation and luminance variation caused by a mobility characteristic change.

In one aspect, the present embodiments provide a display device including a display panel in which a plurality of data lines and a plurality of gate lines are arranged and a plurality of subpixels are arranged, a data driver for driving the plurality of data lines, A gate driver, and a controller for controlling the data driver and the gate driver.

In such an organic light emitting display, each subpixel includes an organic light emitting diode, a driving transistor for driving the organic light emitting diode, and a storage capacitor electrically connected between the first node and the second node of the driving transistor.

The organic light emitting display may further include a sensing unit sensing a voltage of a first node of the driving transistor and outputting a sensing value of a mobility in digital form with respect to the sensed voltage in a mobility sensing period of the driving transistor have.

The sensing unit senses the voltage of the first node of the driving transistor and outputs the nth mobility sensing value in the nth mobility sensing period of the driving transistor. In the n + 1 mobility sensing period of the driving transistor, The voltage of the first node of the driving transistor can be sensed and the (n + 1) -th mobility sensing value can be output.

The controller calculates the nth mobility compensation value from the nth mobility sensing value and controls the n + 1 mobility sensing value sensed in the (n + 1) mth sensing range to have a certain ratio according to the mobility characteristic, 1) mobility sensing data based on the calculated nth mobility compensation value and outputs it to the (n + 1) -th mobility sensing period of the driving transistor, and (n + 1) The mobility compensation value can be calculated.

 In another aspect, the present embodiments provide a method of driving a pixel, comprising: generating mobility sensing data for sensing mobility of a driving transistor in a sub-pixel; outputting mobility sensing data to a data driver; Receiving a mobility sensing value corresponding to the mobility sensing result of the driving transistor in the sub-pixel, calculating a mobility compensation value based on the mobility sensing value; And a step of updating the mobility compensation value previously stored in the memory with the calculated mobility compensation value.

In this compensation method, in the step of generating the mobility sensing data, the mobility sensing value sensed in the mobility sensing interval is calculated based on the previously calculated mobility compensation value, Data for sensing can be generated.

According to the embodiments as described above, it is possible to provide an organic light emitting display device and a compensation method thereof that can more accurately compensate mobility.

Further, according to the embodiments, it is possible to provide an organic light emitting display device and a compensation method thereof that can suppress both the luminance variation caused by the initial mobility characteristic variation and the luminance variation caused by the mobility characteristic variation.

1 is a system configuration diagram of an organic light emitting display according to the present embodiments.
FIG. 2 is a view illustrating a sub-pixel structure of an OLED display according to an embodiment of the present invention. Referring to FIG.
3 is a view illustrating another sub-pixel structure and a compensation circuit of the OLED display according to the present embodiments.
4 is a diagram illustrating a threshold voltage sensing driving method of a driving transistor in an OLED display according to an exemplary embodiment of the present invention.
FIG. 5 is a diagram illustrating a driving method of sensing the mobility of the driving transistor in the OLED display according to the present embodiments. Referring to FIG.
FIG. 6 is a diagram illustrating a sequence of threshold voltage sensing and mobility sensing in an organic light emitting display according to an exemplary embodiment of the present invention. Referring to FIG.
7 is a timing diagram of threshold voltage sensing and mobility sensing in the organic light emitting diode display according to the present embodiments.
8A is a diagram for explaining generation of mobility sensing data for mobility sensing driving and calculation of mobility compensation value based on the mobility sensing value in the organic light emitting display according to the present embodiments.
8B illustrates compensation of image data for displaying an image with the mobility compensation value? _Comp 'calculated based on the mobility sensing value? _Sen in the OLED display 100 according to the present embodiment FIG.
9 is a diagram illustrating mobility compensation through mobility sensing and mobility deviation reduction according to mobility compensation in the OLED display according to the present embodiments.
10 is a graph showing the relationship between the mobility sensitivity values of all the subpixels of the same color in the organic light emitting display panel according to the mobility characteristics in the organic light emitting display 100 according to the present embodiments, FIG. 7 is a graph showing the relationship between the mobility sensitivity values according to the mobility characteristics.
11 is a graph showing the relationship of luminance according to mobility characteristics when an image is displayed in a display period by applying a relation of mobility sensitivity values according to mobility characteristics after mobility compensation in FIG.
12 is a graph showing the relationship between the mobility sensitivity values of all the subpixels of the same color in the organic light emitting diode display panel according to the mobility characteristics, FIG. 5 is a graph showing the relationship between the mobility sensing value and the luminance according to the mobility characteristic.
FIG. 13 is a graph showing the relationship between the mobility sensing value according to the mobility characteristic change for one sub-pixel in the organic light emitting display panel and the relationship between the mobility sensing value after mobility compensation And a mobility sensing value according to mobility characteristics.
FIG. 14 is a graph showing the relationship between the mobility sensitivity values of the organic light emitting display according to the present embodiments and the mobility characteristics of the organic light emitting display In the device 100, the relationship between the mobility sensing value according to the mobility characteristic change and the mobility sensing value and luminance according to the mobility characteristic after mobility compensation, for any one subpixel in the organic light emitting display panel Fig.
FIG. 16 is a graph showing the relationship between the mobility sensitivity values of all the subpixels of the same color in the organic light emitting display panel according to the mobility characteristics, FIG. 5 is a graph showing the relationship between the mobility sensing value and the luminance according to the mobility characteristic.
17A is a diagram for explaining the generation of mobility sensing data for the mobility sensing drive shown in Fig. 16 and the mobility compensation based on the mobility sensing value? _Sen in the OLED display 100 according to the present embodiment. Is a diagram for explaining the calculation of the value (? _Comp ').
FIG. 17B is a graph showing the relationship between the image data representing the image with the mobility compensation value? _Comp 'calculated based on the mobility sensing value? _Sen shown in FIG. 16 in the OLED display 100 according to the present embodiment Fig.
18 is a flowchart of a method of compensating the organic light emitting display 100 according to the present embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

FIG. 1 is a system configuration diagram of an organic light emitting diode display 100 according to the present embodiments.

1, the OLED display 100 includes a plurality of data lines DL and a plurality of gate lines GL, a plurality of sub pixels (SP) A data driver 120 for driving the plurality of data lines DL; a gate driver 130 for driving the plurality of gate lines GL; a data driver 120 And a controller 140 for controlling the gate driver 130 and the like.

The controller 140 supplies various control signals to the data driver 120 and the gate driver 130 to control the data driver 120 and the gate driver 130.

The controller 140 starts scanning according to the timing implemented in each frame, switches the input image data input from the outside according to the data signal format used by the data driver 120, and outputs the converted image data , And controls the data driving at a suitable time according to the scan.

The controller 140 may be a timing controller used in a conventional display technology or a control device including a timing controller to perform other control functions.

The data driver 120 drives the plurality of data lines DL by supplying data voltages to the plurality of data lines DL. Here, the data driver 120 is also referred to as a 'source driver'.

The gate driver 130 sequentially supplies the scan signals to the plurality of gate lines GL to sequentially drive the plurality of gate lines GL. Here, the gate driver 130 is also referred to as a " scan driver ".

The gate driver 130 sequentially supplies a scan signal of an On voltage or an Off voltage to the plurality of gate lines GL under the control of the controller 140.

When a specific gate line is opened by the gate driver 130, the data driver 120 converts the image data received from the controller 140 into an analog data voltage and supplies the data voltage to a plurality of data lines DL.

1, the data driver 120 is located only on one side (e.g., on the upper side or the lower side) of the organic light emitting display panel 110, : Upper side and lower side).

1, the gate driver 130 is located only on one side (e.g., the left side or the right side) of the organic light emitting display panel 110. However, the gate driver 130 may be disposed on both sides of the organic light emitting display panel 110 For example, left and right).

The controller 140 described above is capable of outputting various kinds of signals including the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the input data enable signal (DE), and the clock signal (CLK) Timing signals from the outside (e.g., the host system).

The controller 140 outputs the converted image data by switching the input image data inputted from the outside in accordance with the data signal format used by the data driver 120 and outputs the converted image data to the data driver 120 and the gate driver 130, A timing signal such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, an input DE signal and a clock signal and generates various control signals to control the data driver 120 and the gate driver 130, .

For example, in order to control the gate driver 130, the controller 140 generates a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal GOE Gate Output Enable), and the like.

Here, the gate start pulse GSP controls the operation start timing of one or more gate driver integrated circuits constituting the gate driver 130. The gate shift clock GSC is a clock signal commonly input to one or more gate driver integrated circuits, and controls the shift timing of the scan signal (gate pulse). The gate output enable signal GOE specifies the timing information of one or more gate driver ICs.

In order to control the data driver 120, the controller 140 may further include a source start pulse (SSP), a source sampling clock (SSC), a source output enable signal (SOE) And outputs various data control signals (DCS: Data Control Signals).

Here, the source start pulse SSP controls the data sampling start timing of one or more source driver integrated circuits constituting the data driver 120. The source sampling clock SSC is a clock signal for controlling sampling timing of data in each of the source driver integrated circuits. The source output enable signal SOE controls the output timing of the data driver 120.

The data driver 120 may drive a plurality of data lines including at least one source driver integrated circuit (SDIC).

Each source driver integrated circuit (SDIC) is connected to a bonding pad of the organic light emitting display panel 110 by a tape automated bonding (TAB) method or a chip on glass (COG) Or may be directly disposed on the organic light emitting display panel 110, and may be integrated and disposed on the organic light emitting display panel 110, as the case may be. In addition, each source driver integrated circuit (SDIC) may be implemented by a chip on film (COF) method, which is mounted on a film connected to the organic light emitting display panel 110.

Each source driver integrated circuit (SDIC) may include a latch circuit, a digital to analog converter (DAC), an output buffer, and the like.

Each source driver integrated circuit (SDIC) may further include an analog to digital converter (ADC), as the case may be.

The gate driver 130 may include at least one gate driver integrated circuit (GDIC).

Each gate driver integrated circuit GDIC may be connected to a bonding pad of the organic light emitting display panel 110 by a tape automated bonding (TAB) method or a chip on glass (COG) ) Type and may be directly disposed on the organic light emitting display panel 110 or may be integrated on the organic light emitting display panel 110 as the case may be. In addition, each gate driver IC (GDIC) may be implemented by a chip on film (COF) method, which is mounted on a film connected to the organic light emitting display panel 110.

Each gate driver IC (GDIC) may include a shift register, a level shifter, and the like.

The OLED display 100 according to the present embodiments includes at least one source printed circuit board (S-PCB) necessary for circuit connection to at least one source driver IC (SDIC) And a control printed circuit board (C-PCB) for mounting control components and various electric devices.

At least one source driver integrated circuit (SDIC) may be mounted on at least one source printed circuit board (S-PCB), or a film on which at least one source driver integrated circuit (SDIC) is mounted may be connected.

The control printed circuit board (C-PCB) is provided with a controller 140 for controlling the operation of the data driver 120 and the gate driver 130 and the like, and a controller 140 for controlling operations of the organic light emitting display panel 110, the data driver 120, A power controller for controlling various voltages or currents to supply or supply various voltages or currents to the battery 130, or the like.

The at least one source printed circuit board (S-PCB) and the control printed circuit board (C-PCB) may be circuitly connected via at least one connecting member.

Here, the connecting member may be a flexible printed circuit (FPC), a flexible flat cable (FFC), or the like.

At least one source printed circuit board (S-PCB) and a control printed circuit board (C-PCB) may be integrated into one printed circuit board.

Each sub-pixel SP disposed in the organic light emitting display panel 110 may include a circuit element such as a transistor.

For example, each of the sub-pixels SP may include a circuit element such as an organic light-emitting diode (OLED) and a driving transistor for driving the organic light-emitting diode (OLED).

The types and the number of the circuit elements constituting each subpixel SP can be variously determined depending on the providing function, the design method, and the like.

2 is an exemplary view of a sub-pixel structure of the OLED display 100 according to the present embodiments.

Referring to FIG. 2, in the organic light emitting diode display 100 according to the present embodiment, each sub pixel includes an organic light emitting diode (OLED), an organic light emitting diode (OLED) A switching transistor SWT for transferring a data voltage to a second node N2 corresponding to a gate node of the driving transistor DRT; And a storage capacitor (Cstg) that holds the corresponding data voltage or the corresponding voltage for one frame time.

The organic light emitting diode OLED may include a first electrode (e.g., an anode electrode), an organic layer, and a second electrode (e.g., a cathode electrode).

The driving transistor DRT drives the organic light emitting diode OLED by supplying a driving current to the organic light emitting diode OLED.

The first node N1 of the driving transistor DRT may be electrically connected to the first electrode of the organic light emitting diode OLED and may be a source node or a drain node. The second node N2 of the driving transistor DRT may be electrically connected to the source node or the drain node of the switching transistor SWT and may be a gate node. The third node N3 of the driving transistor DRT may be electrically connected to a driving voltage line DVL for supplying a driving voltage EVDD and may be a drain node or a source node.

The driving transistor DRT and the switching transistor SWT may be implemented as an n-type or a p-type as illustrated in FIG.

The switching transistor SWT is electrically connected between the data line DL and the second node N2 of the driving transistor DRT and can be controlled by receiving the scan signal SCAN through the gate line to the gate node .

The switching transistor SWT may be turned on by the scan signal SCAN to transfer the data voltage Vdata supplied from the data line DL to the second node N2 of the driving transistor DRT.

The storage capacitor Cstg may be electrically connected between the first node N1 and the second node N2 of the driving transistor DRT.

The storage capacitor Cstg is not a parasitic capacitor (e.g., Cgs or Cgd) which is an internal capacitor existing between the first node N1 and the second node N2 of the driving transistor DRT, And is an external capacitor intentionally designed outside the driving transistor DRT.

In the OLED display 100 according to the present embodiment, as the driving time of each sub-pixel SP becomes longer, the driving voltage of the organic light emitting diode OLED, the driving transistor DRT, Degradation can proceed.

Accordingly, inherent characteristic values (e.g., threshold voltage, mobility, etc.) of the circuit elements such as the organic light emitting diode OLED and the driving transistor DRT can be changed.

Such a change in the characteristic value of the circuit element causes the luminance change of the corresponding subpixel. Therefore, the change in the characteristic value of the circuit element can be used in the same concept as the change in luminance of the subpixel.

In addition, the degree of change in the characteristic value between the circuit elements may be different depending on the degree of deterioration of each circuit element.

Such a characteristic value deviation between the circuit elements causes a luminance deviation between the subpixels. Therefore, the characteristic value deviation between the circuit elements can be used in the same concept as the luminance deviation between the subpixels.

The above-described subpixel luminance variation and subpixel luminance variation may cause problems such as degradation of the accuracy with respect to the luminance expression power of the subpixels or occurrence of screen abnormal phenomenon.

Here, the characteristic value of a circuit element (hereinafter also referred to as a " subpixel characteristic value ") may include, for example, a threshold voltage and a mobility of a driving transistor DRT, May include the threshold voltage of the transistor.

The OLED display 100 according to the present embodiment has a sensing function for sensing a sub-pixel luminance change and a sub-pixel luminance deviation (a characteristic value change of a circuit element and a characteristic value deviation between circuit elements) The compensation function for compensating the sub-pixel luminance variation and the sub-pixel luminance deviation can be provided.

The organic light emitting diode display 100 according to the present embodiment includes a subpixel structure and a sensing and compensation structure corresponding thereto to provide a sensing and compensating function for a subpixel luminance change and a luminance deviation between subpixels Compensation circuit.

3 is an exemplary view of another sub-pixel structure and a compensation circuit of the OLED display 100 according to the present embodiments.

Referring to FIG. 3, each sub-pixel disposed in the organic light emitting display panel 110 according to the present exemplary embodiment includes an organic light emitting diode OLED, a driving transistor DRT, a switching transistor SWT, In addition to the capacitor Cstg, it may further include a sensing transistor SENT.

3, the sensing transistor SENT is electrically connected between a first node N1 of the driving transistor DRT and a reference voltage line RVL for supplying a reference voltage Vref And may be controlled by receiving a sensing signal SENSE, which is a kind of a scan signal, to the gate node.

The sensing transistor SENT is turned on by the sensing signal SENSE to apply a reference voltage Vref supplied through the reference voltage line RVL to the first node N1 of the driving transistor DRT.

Also, the sensing transistor SENT may be utilized as one of the voltage sensing paths for the first node N1 of the driving transistor DRT.

Meanwhile, the scan signal SCAN and the sense signal SENSE may be separate gate signals. In this case, the scan signal SCAN and the sense signal SENSE may be respectively applied to the gate node of the switching transistor SWT and the gate node of the sensing transistor SENT through another gate line.

In some cases, the scan signal SCAN and the sense signal SENSE may be the same gate signal. In this case, the scan signal SCAN and the sense signal SENSE may be commonly applied to the gate node of the switching transistor SWT and the gate node of the sensing transistor SENT through the same gate line.

Referring to FIG. 3, the organic light emitting display 100 according to the present embodiment senses a deviation between a sub-pixel characteristic value (a characteristic value of the driving transistor, a characteristic of the organic light emitting diode) and / A memory 320 for storing sensing data, a compensation unit for compensating a variation between subpixel characteristic values and / or subpixel characteristic values using sensing data, 330), and the like.

The sensing unit 310 may include at least one analog-to-digital converter (ADC).

Each analog-to-digital converter (ADC) may be included inside the source driver integrated circuit (SDIC) and, in some cases, may be included outside the source driver integrated circuit (SDIC).

The compensation unit 330 may be included inside the controller 140 and, in some cases, may be included outside the controller 140.

The sensing data output from the sensing unit 310 may be, for example, a Low Voltage Differential Signaling (LVDS) data format.

The organic light emitting diode display 100 according to the present exemplary embodiment is configured to control the driving of the driving transistor DRT within the subpixel SP by controlling the voltage application state of the first node N1 in the subpixel SP, And may further include a first switch SW1 and a second switch SW2 in order to control a state required for sensing.

The supply of the reference voltage Vref to the reference voltage line RVL can be controlled through the first switch SW1.

When the first switch SW1 is turned on, the reference voltage Vref is supplied to the reference voltage line RVL and is supplied to the first node N1 of the driving transistor DRT through the sensing transistor SENT, ). ≪ / RTI >

On the other hand, when the voltage of the first node N1 of the driving transistor DRT becomes a voltage state reflecting the sub-pixel characteristic value, the reference voltage line (which may be of the same potential as the first node N1 of the driving transistor DRT RVL may be a voltage state reflecting the sub-pixel characteristic value. At this time, the line capacitor Csen formed on the reference voltage line RVL may be charged with a voltage reflecting the sub-pixel characteristic value.

The second switch SW2 is turned on and the sensing unit 310 and the reference voltage line RVL are turned on when the voltage of the first node N1 of the driving transistor DRT becomes a voltage state reflecting the sub- Can be connected.

Accordingly, the sensing unit 310 senses the voltage of the reference voltage line RVL, that is, the voltage of the first node N1 of the driving transistor DRT, which is a voltage state reflecting the sub-pixel characteristic value. Here, the reference voltage line RVL is also referred to as a " sensing line ".

The reference voltage lines RVL may be arranged, for example, one for each sub-pixel column, or one for each of two or more sub-pixel columns.

For example, when one pixel is composed of four subpixels (red subpixel, white subpixel, green subpixel, and blue subpixel), the reference voltage line RVL is divided into four subpixel columns , A white subpixel column, a green subpixel column, and a blue subpixel column).

When the sensing unit 310 is connected to the reference voltage line RVL, the voltage of the first node N1 of the driving transistor DRT (the voltage of the reference voltage line RVL or the voltage of the line on the reference voltage line RVL) The voltage charged in the capacitor Csen).

The voltage sensed by the sensing unit 310 may be either a voltage value Vdata-Vth or Vdata-? Vth including a threshold voltage Vth or a threshold voltage deviation? Vth of the driving transistor DRT, May be a voltage value for sensing the degree of mobility.

In the following, the threshold voltage sensing drive and the mobility sensing drive for the driving transistor DRT will be briefly described.

First, a threshold voltage sensing driving method for the driving transistor DRT will be briefly described with reference to FIG.

4 is a diagram illustrating a threshold voltage sensing driving method of a driving transistor in an OLED display according to an exemplary embodiment of the present invention.

4, when the threshold voltage sensing operation of the driving transistor DRT is performed, the first node N1 and the second node N2 of the driving transistor DRT are driven by the reference voltage Vref and the threshold voltage sensing driving (Vdata).

Thereafter, the first switch SW1 is turned off, and the first node N1 of the driving transistor DRT is floated.

As a result, the voltage of the first node N1 of the driving transistor DRT rises.

When the voltage of the first node N1 of the driving transistor DRT rises for a predetermined time, the rising width gradually decreases and becomes saturated.

The saturated voltage of the first node N1 of the driving transistor DRT may correspond to the difference between the data voltage Vdata and the threshold voltage Vth or the difference between the data voltage Vdata and the threshold voltage deviation Vth .

When the voltage of the first node N1 of the driving transistor DRT is saturated, the sensing unit 310 turns on the second switch SW2 and is connected to the reference voltage line RVL.

Accordingly, the sensing unit 310 senses the saturated voltage of the first node N1 of the driving transistor DRT.

The voltage Vsen sensed by the sensing unit 310 is a voltage Vdata-Vth obtained by subtracting the threshold voltage Vth from the data voltage Vdata or a voltage Vdata-Vth obtained by subtracting the threshold voltage deviation Vth from the data voltage Vdata Vdata -? Vth).

Next, the mobility sensing driving method for the driving transistor DRT will be briefly described with reference to Fig.

5, when the mobility sensing operation is performed, the first node N1 and the second node N2 of the driving transistor DRT are respectively connected to the reference voltage Vref and the mobility sensing driving data voltage Vdata Is initialized.

Thereafter, the first switch SW1 is turned off, and the first node N1 of the driving transistor DRT is floated.

As a result, the voltage of the first node N1 of the driving transistor DRT rises.

At this time, the rising speed of the voltage of the first node N1 of the driving transistor DRT indicates the current capability of the driving transistor DRT, that is, the mobility?.

Accordingly, the voltage of the first node N1 of the driving transistor DRT increases more sharply as the driving transistor DRT having a higher current capability (mobility) is.

Here, the rising speed of the voltage at the first node N1 of the driving transistor DRT corresponds to the slope of FIG. 5 as the voltage variation amount? V over a certain period of time.

When a predetermined time elapses after the first node N1 of the driving transistor DRT is floated, the sensing unit 310 turns on the second switch SW2 and is connected to the reference voltage line RVL.

At this time, the sensing unit 310 senses the rising voltage of the first node N1 of the driving transistor DRT whose voltage has been increased for a predetermined period of time, that is, the voltage of the first node N1 of the driving transistor DRT And senses the voltage of the line capacitor Csen on the reference voltage line RVL with the voltage rise together.

That is, the voltage Vsen corresponding to the current Ids flowing through the driving transistor DRT is stored in the line capacitor Csen, and the sensing unit 310 senses the voltage Vsen stored in the line capacitor Csen .

At this time, the mobility α of the driving transistor DRT is inversely proportional to the square of the data voltage Vdata and may be proportional to the line capacitance Csen and the sensing voltage Vsen, as shown in the following equation (1).

It can also be seen from equation (1) that the sensing voltage Vsen is sensed higher as the mobility α is larger.

The sensing unit 310 converts the sensed voltage Vsen to a sensing value corresponding to a digital value for threshold voltage sensing or mobility sensing according to the threshold voltage or mobility sensing driving method as described above, And generates and outputs sensing data including a sensing value.

The sensing data output from the sensing unit 310 may be stored in the memory 320 or may be provided to the compensating unit 330.

The compensation unit 330 may store the characteristic values (e.g., threshold voltage, mobility) of the driving transistor DRT in the corresponding subpixel or the driving transistor DRT based on the sensing data stored in the memory 320 or provided by the sensing unit 310, (E.g., a change in threshold voltage and a change in mobility) of the characteristic value of the target object, and perform characteristic value compensation process.

Here, the characteristic value change of the driving transistor DRT means that the current sensing data is changed based on the previous sensing data, or the current sensing data is changed based on the mobility sensing reference data.

Here, when comparing the characteristic value or the characteristic value change between the driving transistors DRT, it is possible to grasp the characteristic value deviation between the driving transistors DRT. When the characteristic value change of the driving transistor DRT means that the current sensing data is changed on the basis of the reference data for the mobility sensing, the deviation of the characteristic value between the driving transistors DRT from the characteristic value change of the driving transistor DRT Luminance deviation) can be grasped.

The characteristic value compensation process may include a threshold voltage compensation process for compensating the threshold voltage of the driving transistor DRT and a mobility compensation process for compensating the mobility of the driving transistor DRT.

The threshold voltage compensation process may be performed by calculating a compensation value for compensating for a threshold voltage or a threshold voltage deviation (threshold voltage change), storing the calculated compensation value in the memory 320, For example.

The mobility compensation process calculates a compensation value to compensate for mobility or mobility deviation (mobility change), stores the calculated compensation value in the memory 320, or stores the corresponding image data Data as the calculated compensation value, For example.

3, the compensation unit 330 changes the image data Data through the threshold voltage compensation process or the mobility compensation process, and supplies the changed data to the corresponding source driver integrated circuit (SDIC) in the data driver 120 I can do it.

Accordingly, the source driver IC (SDIC) converts the changed data into the data voltage through the digital-to-analog converter 340 and supplies the data voltage to the corresponding subpixel so that the subpixel characteristic value compensation (threshold voltage compensation, mobility compensation) .

By compensating for the subpixel characteristic value, luminance deviation between the subpixels is reduced or prevented, thereby improving the image quality.

FIG. 6 is a diagram illustrating a sequence of threshold voltage sensing and mobility sensing in the organic light emitting diode display 100 according to the present embodiment. FIG. 7 is a timing diagram of the organic light emitting diode display 100 according to the present embodiment. FIG. 3 is a timing diagram of threshold voltage sensing and mobility sensing in FIG.

Referring to FIG. 6, the organic light emitting diode display 100 according to the exemplary embodiments of the present invention performs threshold voltage sensing of the driving transistor DRT, and then performs mobility sensing of the driving transistor DRT.

In the following, it is assumed that the threshold voltage sensing of the driving transistor DRT is performed before the mobility of the driving transistor DRT is sensed.

Accordingly, the compensation value for the threshold voltage of the driving transistor DRT is calculated before the mobility of the driving transistor DRT is sensed, and the threshold voltage compensation value is reflected in the mobility sensing data.

The threshold voltage sensing of the driving transistor DRT requires a relatively long time compared to the mobility sensing of the driving transistor DRT because the voltage saturation time of the first node N1 of the driving transistor DRT is required .

In view of this, for example, as shown in Fig. 7, the threshold voltage sensing of the driving transistor DRT may proceed while the image is not driven, after the power-off signal occurs according to user input or the like.

The mobility sensing of the driving transistor DRT can be performed even after the power-off signal has been generated, but it can also proceed during image driving in view of the fact that it takes a short time.

Therefore, as shown in Fig. 7, the mobility sensing of the driving transistor DRT can proceed after the power-on signal is generated.

In addition, as shown in FIG. 7, the mobility sensing of the driving transistor DRT may proceed at every blank time between active times based on the vertical synchronization signal Vsync.

For example, in one blank time, the mobility sensing of the driving transistor DRT in one sub-pixel may proceed, and in some cases, the mobility sensing of the driving transistor DRT in two or more sub- .

8A is a graph showing the relationship between the generation of mobility sensing data for mobility sensing driving and the mobility compensation value? _Comp 'based on the mobility sensing value? _Sen in the OLED display 100 according to the present embodiment. Fig.

8A, the controller 140 of the organic light emitting diode display 100 according to the present exemplary embodiment generates data for mobility sensing for driving the mobility sensing in the mobility sensing period, .

The data driver 120 generates a data voltage Vdata 'for mobility sensing through digital-analog conversion of the data for sensing the mobility. In the following description, the data voltage for sensing the mobility is denoted by Vdata 'and the data voltage used for generating the mobility sensing data voltage Vdata' is denoted by Vdata.

Referring to FIG. 8A, the process of generating data for mobility sensing will be described using a voltage expression scheme.

The mobility sensing data is generated based on the mobility sensing reference data, the previously stored threshold voltage compensation value (Vth_comp), and the previously stored mobility compensation value (? _Comp).

The mobility sensing data voltage (Vdata ') obtained by converting the mobility sensing data into analog data is calculated based on the reference sensing data voltage (Vdata), threshold voltage compensation value (Vth_comp) and mobility compensation Value (? _Comp) or the like. However, the threshold voltage compensation value (Vth_comp) and the mobility compensation value (? _Comp) are expressed without distinguishing between a digital value and an analog value for convenience of explanation.

More specifically, the data voltage Vdata 'for sensing the mobility may be expressed by the following equation (2).

In Equation (2), g 'is a gain multiplied by the data voltage (Vdata) for sensing the reference mobility. The gain g' is calculated by D corresponding to a coefficient for optimizing mobility compensation and ) And adding one.

When the mobility sensing period is reached, the mobility sensing data voltage Vdata 'expressed as described above is generated and supplied to the second node N2 of the driving transistor DRT in the subpixel to be mobility-sensed .

The sensing unit 310 senses the voltage of the first node N1 of the driving transistor DRT whose voltage has risen in accordance with the current capability of the driving transistor DRT through the line capacitor Csen do.

The sensing unit 310 obtains the mobility sensing value? _Sen through the analog-to-digital conversion on the sensing voltage Vsen and provides it to the controller 140.

The controller 140 calculates the mobility compensation value? _Comp 'for the driving transistor DRT in the corresponding subpixel based on the mobility sensing value? _Sen.

More specifically, the controller 140 multiplies the difference between the mobility sensing value (? _Sen) and the reference mobility sensing value (? _Ref) by a predetermined coefficient (-r) as shown in the following equation (3) (?).

The controller 140 obtains a value?? / K obtained by dividing the mobility sensing deviation? By the predetermined constant k and the existing mobility compensation value? _Comp previously calculated and stored as shown in the following equation (4) In addition, a new mobility compensation value? _Comp 'can be calculated.

The controller 140 updates the existing mobility compensation value? _Comp stored in the memory 320 to the newly calculated mobility compensation value? _Comp '.

8B illustrates compensation of image data for displaying an image with the mobility compensation value? _Comp 'calculated based on the mobility sensing value? _Sen in the OLED display 100 according to the present embodiment FIG.

Referring to FIG. 8B, a process of generating image data will be described as a voltage expression scheme.

Referring to FIG. 8B, in a display period in which an image in an active time is displayed based on a vertical synchronization signal Vsync, a subpixel SP displays an image. In order to display an image, the controller 140 generates the compensated image data based on the externally input image data, the stored threshold voltage compensation value (Vth_comp) and the previously stored mobility compensation value (? _Comp) do. In other words, the controller 140 generates the compensated image data using Equation (2) as in the case of generating the data voltage Vdata 'for sensing the mobility.

The previously stored mobility compensation value? _Comp is the mobility compensation value? _Comp updated with the mobility compensation value? _Comp 'calculated by Equation (4). Accordingly, the compensated image data is affected by the updated mobility compensation value? _Comp, and the luminance of the image displayed in the display period is affected by the mobility compensation value? _Comp.

Referring to FIG. 9, a mobility compensation according to the change (increase or decrease) of the mobility by applying the mobility sensing method described above and how the mobility varies with the mobility compensation will be briefly described.

9 is a diagram illustrating mobility compensation through mobility sensing and mobility deviation reduction according to mobility compensation in the OLED display 100 according to the present embodiments.

Referring to FIG. 9, in a first mobility sensing period for a subpixel, at a time point when the voltage of the first node N1 of the driving transistor DRT rises for a predetermined time (dotted line notation), the sensing unit 310 ) Senses the voltage of the first node N1 of the driving transistor DRT. At this time, the sensed voltage Vsen differs depending on the mobility?.

If the mobility (?) Rises and the mobility (?) Decreases (decreases) when the mobility (?) Rises and the mobility (?) Of the drive transistor (DRT) The voltage Vsen is lowered.

When the mobility α of the driving transistor DRT rises and the sensing voltage Vsen rises, the mobility compensation value α compensation value decreases.

When the mobility α of the driving transistor DRT decreases and the sensing voltage Vsen decreases, the mobility α compensation value increases.

When the second mobility sensing for the same subpixel is performed using the thus calculated mobility compensation value, the same sensing voltage Vsen can be sensed. That is, it can be seen that the mobility is compensated.

10 is a graph showing the relationship between the mobility sensitivity values of all the subpixels of the same color in the organic light emitting display panel according to the mobility characteristics in the organic light emitting display 100 according to the present embodiments, FIG. 7 is a graph showing the relationship between the mobility sensitivity values according to the mobility characteristics. 11 is a graph showing the relationship of luminance according to mobility characteristics when an image is displayed in a display period by applying a relation of mobility sensitivity values according to mobility characteristics after mobility compensation in FIG. 12 is a graph showing the relationship between the mobility sensitivity values of all the subpixels of the same color in the organic light emitting diode display panel according to the mobility characteristics, FIG. 5 is a graph showing the relationship between the mobility sensing value and the luminance according to the mobility characteristic.

10, all the subpixels of the same color (for example, in the initial sensing period in which the mobility is not compensated before release of the product) in the first mobility sensing period , A subpixel of one of R, W, G and B subpixels) has a certain rate that linearly increases the mobility sensing value according to the mobility characteristic of the driving transistor DRT. The driving transistor DRT included in all the subpixels of the same color (for example, one of the R, W, G, and B subpixels) in the organic light emitting display panel 110 during the initial sensing period The drift characteristic may mean the initial scattering of the mobility of the driving transistor DRT.

In other words, as the mobility characteristic of the driving transistor DRT increases, the mobility sensing value of the driving transistor DRT also increases linearly. At this time, the fact that the mobility sensing value according to the mobility characteristic of the driving transistor DRT has a linearly increasing ratio indicates that the slope of the mobility sensing value according to the mobility characteristic of the driving transistor DRT has a certain magnitude .

When the mobility characteristic of the driving transistor DRT is high (high?), The mobility compensation value (? Compensation value) is smaller than 1 (? Compensation value <1). In contrast, when the mobility characteristic of the driving transistor DRT is small (low?), The mobility compensation value? Compensation value is larger (? Compensation value> 1).

At this time, the mobility compensation value calculated by adjusting the data voltage (Vdata ') for mobility sensing by using the optimum coefficient D value (D optimum in Figs. 10 and 12) for optimizing the mobility compensation is applied If the second mobility sensing for all the subpixels of the same color in the organic light emitting display panel 110 is performed at the second mobility sensing period (for example, the update sensing period using the mobility compensation value) The mobility sensing values according to the mobility characteristics of the driving transistor DRT included in all the subpixels of the same color in the organic light emitting display panel 110 have the same value. Having the same value means that the slope of the mobility sensing value according to the mobility characteristic of the driving transistor DRT is zero. At this time, the slope of 0 may mean that the range has a value that does not substantially affect the mobility compensation value using the mobility sensing value (the same applies hereinafter).

Referring to FIG. 12, the second mobility sensing (update mobility sensing) is a method of modifying the mobility compensation value to the sensed sensing value, which is affected by the coefficient D because the coefficient D is applied during the update mobility sensing. If the coefficient D is an optimal value, the updated mobility sensing value is sensed equally and the mobility compensation value is not modified.

On the other hand, by applying the coefficient D value (smaller than D in Figs. 10 and 12) smaller than the optimum D value (D optimum in Figs. 10 and 12), the data voltage Vdata ' When the second mobility sensing for all the subpixels of the same color in the organic light emitting display panel 110 is performed in the second mobility sensing period using the adjusted mobility compensation value, The mobility sensing value according to the mobility characteristics of the driving transistor DRT included in all the sub-pixels of the same color in the pixel 110 increases linearly.

Conversely, by applying the coefficient D value (D greater) than the optimum coefficient D value (D optimum in FIGS. 10 and 12), the calculated data voltage Vdata ' The second mobility sensing for all the subpixels of the same color in the organic light emitting display panel 110 is performed in the second mobility sensing period using the compensation value, The mobility sensing value according to the mobility characteristics of the driving transistor DRT included in all the sub-pixels of the driving transistor DRT linearly decreases.

In other words, when the coefficient D is small, the mobility compensation is insufficient at the sensing of the mobility, and the mobility characteristic is weakly sensed to the mobility sensing value, and the mobility compensation value deviation becomes larger. When the coefficient D is large, the mobility compensation is excessive at the sensing of the mobility, and the mobility characteristic is reversely sensed to the mobility sensing value, so that the mobility compensation value deviation becomes small.

In this case, as shown in FIG. 11 and FIG. 12, when the image data is compensated by applying the mobility compensation value to which the updated mobility sensing value is applied in the display period, the same luminance Optimum) can be obtained.

FIG. 13 is a graph showing the relationship between the mobility sensing value according to the mobility characteristic change for one sub-pixel in the organic light emitting display panel and the relationship between the mobility sensing value after mobility compensation And a mobility sensing value according to mobility characteristics. FIG. 14 is a graph showing a relationship of luminance according to mobility characteristics when images are displayed in a display period by applying a relation of mobility sensitivity values according to mobility characteristics after mobility compensation in FIG.

13, when the mobility characteristic of the driving transistor DRT included in one sub-pixel changes in the n-th degree of mobility sensing period (for example, the update sensing period in which the mobility compensation is performed at a specific time point after the product is released) The mobility sensing value has a constant rate that linearly increases. At this time, the mobility characteristics of the driving transistor DRT included in one of the sub-pixels in the organic light emitting display panel 110 during the update sensing period may be changed by the temperature mobility of the driving transistor DRT, It means that it becomes smaller.

That is, when the mobility characteristic of the driving transistor DRT increases, the mobility sensing value of the driving transistor DRT also increases linearly.

When the mobility characteristic of the driving transistor DRT is high (high?), The mobility compensation value (? Compensation value) is smaller than 1 (? Compensation value <1). In contrast, when the mobility characteristic of the driving transistor DRT is small (low?), The mobility compensation value? Compensation value is larger (? Compensation value> 1).

At this time, the D value for optimizing the mobility compensation is applied to adjust the data voltage (Vdata ') for the mobility sensing according to Equation (2), and the mobility compensation value calculated using the calculated mobility compensation value When the next n + 1 mobility sensing for any one subpixel in the organic light emitting display panel 110 is performed in the update sensing period using the mobility compensation value calculated in the nth movement sensitivity sensing period, The slope of the mobility sensing value according to the mobility characteristic of the driving transistor DRT is the same as the mobility sensing value according to the mobility characteristic of the driving transistor DRT included in one sub pixel of the display panel 110 0).

That is, when the mobility characteristic changes due to temperature change, the mobility sensing value is changed and the mobility compensation value is corrected to the mobility sensing value. Finally, the mobility compensation value is corrected so that the same current flows to the sensing line through the driving transistor during the (n + 1) -th mobility sensing period.

Since the same current flows when the mobility is compensated for the n + 1 mobility sensing while optimizing the D value (generally optimized for D = 1, depending on the product model) with respect to the mobility deviation during sensing of the nth mobility, Values are sensed equally.

However, as shown in FIG. 14, when the image data is compensated by applying the mobility compensation value to which the updated mobility sensing value is applied in the display period, the luminance is actually the same even if the currents flowing during the mobility sensing are the same Do not. This is because the current may increase more than the increase of the mobility sensing value in the display period due to the nonlinearity of the voltage-current characteristics of the driving transistor, the temperature characteristic of the organic light emitting diode, and the influence of the switching transistor. Similarly, the current can be reduced to a greater extent than the decrease in the mobility sensing value at the time of emission of the subpixel in the display period. Therefore, even if the mobility sensing value converges to the same value during the (n + 1) -th mobility sensing, the luminance may not converge in the display period.

FIG. 15 is a graph showing the relationship between the mobility sensing value according to the mobility characteristic change for one sub-pixel in the organic light emitting display panel and the relationship between the mobility sensing value after mobility compensation FIG. 5 is a graph showing the relationship between the mobility sensitivity value and the luminance according to the mobility characteristic.

Referring to FIG. 15, the mobility compensation value is also modified in the same manner with respect to the mobility characteristic change. The difference is that the brightness is not the same depending on the mobility characteristic change despite the mobility compensation when using the optimum D with the same mobility sensing value.

12 and 15, optimization of the coefficient D in accordance with the initial scattering makes it possible to equalize the luminance deviation caused by the initial scattering, but the effect is small with respect to the luminance change caused by the mobility characteristic change. If the coefficient D is made small in accordance with the change in the mobility characteristic due to the temperature change or the like, the initial luminance deviation is inverted. That is, the luminance of a pixel having a high mobility characteristic is lowered.

Although the initial dispersion and the change of the mobility characteristics are different phenomena, the coefficient D applied to the organic light emitting display panel 110 is different from that of the same color There is only one for the subpixels (R, G, B, W), so it is necessary to apply the gradation D satisfying both conditions.

Hereinafter, an organic light emitting display device and its compensation method using an optimum D capable of simultaneously improving initial scattering and change of mobility characteristics will be described.

FIG. 16 is a graph showing the relationship between the mobility sensitivity values of all the subpixels of the same color in the organic light emitting display panel according to the mobility characteristics, FIG. 5 is a graph showing the relationship between the mobility sensing value and the luminance according to the mobility characteristic.

Referring to FIG. 16, the mobility sensing value of the driving transistor DRT included in all the subpixels of the same color in the nth mobility sensing period has a certain rate that the mobility sensing value increases linearly. In other words, as the mobility characteristic of the driving transistor DRT increases, the mobility sensing value of the driving transistor DRT also increases linearly.

The nth mobility compensation value thus calculated is multiplied by a coefficient D for optimizing the mobility compensation to generate data for the (n + 1) -th mobility sensing based on the modified nth mobility compensation value. 16) by applying a coefficient D value (smaller than D in Fig. 16) smaller than an optimum coefficient D value (D optimum in Fig. 16) at this time, and calculating a mobility value Vdata ' When the next n + 1 mobility sensing for all the subpixels of the same color in the OLED panel 110 is performed during the (n + 1) -th mobility sensing period using the compensation value, The mobility sensing value according to the mobility characteristic of the driving transistor DRT included in all the sub-pixels of the same color has a constant ratio. In this case, the (n + 1) -th mobility sensing value sensed in the (n + 1) -th mobility sensing period has a constant rate that linearly increases according to the mobility characteristic.

At this time, the coefficient D value for optimizing the mobility compensation of the data voltage Vdata 'for the mobility sensing is obtained by multiplying the n + 1 mobility sensing value sensed in the (n + 1) (D optimal in Fig. 16) for optimizing the mobility compensation used to have the mobility compensation.

And calculates the n + 1 mobility compensation value (D in Fig. 16) from the n + 1 mobility sensing value in the (n + 1) -th mobility sensing period.

Similarly, the (n + 2) -th mobility sensing for all the subpixels of the same color in the OLED panel 110 is performed using the (n + 1) -th mobility compensation value The mobility sensing values according to the mobility characteristics of the driving transistor DRT included in all the subpixels of the same color in the organic light emitting display panel 110 are linearly converged.

And compensates for the image data of the subpixel displaying the image based on the calculated n + 1 mobility compensation value, and outputs it to the display section. The subpixel has the same luminance (optimum) depending on the mobility characteristic in the display period.

Hereinafter, in the organic light emitting display 100 according to the present embodiments, the relationship of the mobility sensitivity values for all the subpixels of the same color in the organic light emitting display panel, The relationship between the mobility sensing value and the luminance according to the mobility characteristics will be described with reference to Figs. 17A and 17B.

The sensing unit 310 senses the voltage of the first node of the driving transistor in the nth mobility sensing period of the driving transistor to output the nth mobility sensing value, and the (n + 1) Senses the voltage of the first node of the driving transistor and outputs the (n + 1) -th mobility sensing value.

As shown in Fig. 17A, the controller 140 calculates the n-th mobility compensation value from the n-th mobility sensing value, and the (n + 1) -th mobility sensing value The data for sensing the (n + 1) -th mobility is generated based on the calculated n-th mobility compensation value to output the data for the n + 1-mobility sensing period of the driving transistor so as to have a certain ratio according to the mobility characteristics, + 1 mobility compensation value from the +1 mobility sensing value. The reason why the n + 1 mobility sensing value sensed in the (n + 1) -th mobility sensing period has a certain ratio according to the mobility characteristics is that the mobility sensing value according to the mobility characteristic of the driving transistor DRT Is not the same and the slope of the mobility sensing value has a certain magnitude.

As a result, the (n + 1) -th mobility sensing value sensed in the (n + 1) -th mobility sensing period has a constant rate that linearly increases with the mobility characteristic. For example, the n + 1 mobility sensing value has been described as having a linearly increasing ratio according to the mobility characteristic. However, the n + 1 mobility sensing value is a constant rate that linearly increases with the mobility characteristic , But may have a constant ratio that increases nonlinearly, for example, by a cubic function.

The controller 140 multiplies the calculated nth mobility compensation value by a coefficient for optimizing the mobility compensation, and generates data for the (n + 1) -th mobility sensing based on the modified nth mobility compensation value. For example, the nth mobility compensation value is multiplied by a coefficient for optimizing the mobility compensation, and the nth mobility compensation value is modified to generate data for the (n + 1) mobility sensing. However, It is not limited.

In Equation (5), g 'is a gain multiplied by the data voltage (Vdata) for sensing the reference mobility. The gain g' is determined by D 'and (? 1) and adding one.

The controller 140 compensates the image data of the subpixel displaying the image based on the calculated n + 1 mobility compensation value and outputs it to the data driver 120 in the display period, as shown in Fig. 17B. The data driver 120 outputs the compensated image data to the corresponding subpixel. The corresponding subpixel emits the luminance corresponding to the compensated image data. The subpixel has the same luminance (optimal in Fig. 16) depending on the mobility characteristic in the display period.

At this time, the controller 140 compares the pre-stored target mobility sensing value (target in FIG. 16) having the predetermined ratio according to the mobility characteristic with the nth mobility sensing value, and if not, (N + 1) mobility sensing data (Vdata ') based on the corrected nth mobility compensation value. In other words, when generating the n + 1 mobility sensing data (Vdata '), the mobility compensation value is corrected by comparing the target mobility sensing value previously stored in the memory 320 with the actually sensed mobility sensing value, The next mobility sensing can be performed based on the mobility compensation value. The controller 140 compares the pre-stored target mobility sensing value having a certain ratio according to the mobility characteristics with the n-th mobility sensing value, and if the mobility sensing value matches the n-th mobility sensing value, And generates data (Vdata ') for sensing the (n + 1) -th mobility, based on the n-th mobility compensation value.

In addition, according to the embodiments, the organic light emitting diode display 100 can suppress both the luminance variation due to the initial mobility characteristic deviation and the luminance variation caused by the mobility characteristic variation.

Hereinafter, a method for compensating the organic light emitting display 100 according to the present invention will be briefly described below.

18 is a flowchart of a method of compensating the organic light emitting display 100 according to the present embodiments.

18, the method of compensating the organic light emitting display 100 according to the present embodiment includes generating data for mobility sensing for sensing the mobility of the driving transistor DRT in the sub-pixel SP, (Step S810), outputting the data for sensing the mobility to the data driver 120 (S820), and a step for determining whether or not the mobility sensing data of the driving transistor DRT in the sub- (Step S830) of receiving the corresponding mobility sensing value? _Sen and a mobility compensation value? _Comp 'based on the mobility sensing value? _Sen and calculating the mobility compensation value? Updating the mobility compensation value? _Comp previously stored in the memory 320 (S840), and the like.

In the step S810 of generating the mobility sensing data, the mobility sensing value? _Sen, which is sensed in the mobility sensing period based on the previously calculated mobility compensation value, is shifted so that the mobility sensing value? And generates data for sensing (Vdata '). As described above, the mobility sensing value (? _Sen) sensed in the mobility sensing period has a constant rate that linearly increases with the mobility characteristic.

On the other hand, in step S810 of generating the mobility sensing data, the previously calculated mobility compensation value? _Comp is multiplied by a coefficient D for optimizing the mobility compensation, and based on the mobility compensation value, (Vdata '). As described above, the coefficient D for optimizing the mobility compensation is smaller than the coefficient for optimizing the mobility compensation used so that the mobility sensing value sensed in the mobility sensing interval has the same ratio according to the mobility characteristic Respectively.

On the other hand, in the step S2150 of calculating the mobility compensation value? _Comp 'based on the mobility sensing value? _Sen in accordance with the step S820 of outputting the mobility sensing data to the data driver 120, The mobility compensation value? _Comp 'for the subpixel SP can be calculated based on the sensing value? _Sen.

The method further includes compensating for the image data (data) of the subpixel displaying the image based on the calculated mobility compensation value (? _Comp ') and outputting the compensated image data to the display section. At this time, the subpixel has the same luminance according to the mobility characteristic in the display period.

The method may further include the step of comparing the pre-stored target mobility sensing target having a certain ratio according to the mobility characteristic and the previously calculated mobility sensing value? _Sen. If the target mobility sensing value target and the previously calculated mobility sensing value? _Sen do not match in the step S810 of generating the mobility sensing data, the previously calculated mobility sensing value? The corrected mobility compensation value? _Comp 'is calculated, and mobility sensing data is generated based on the corrected mobility compensation value? _Comp'.

By using the above-described compensation method, it is possible to suppress both the luminance deviation due to the initial mobility characteristic deviation and the luminance change caused by the mobility characteristic change.

According to the embodiments as described above, it is possible to provide the organic light emitting diode display 100 and the compensation method thereof that can more accurately compensate mobility.

Further, according to the embodiments, it is possible to provide the organic light emitting diode display 100 and the compensation method thereof that can suppress both the luminance variation caused by the initial mobility characteristic deviation and the luminance variation caused by the mobility characteristic change .

According to the embodiments, it is possible to provide the OLED display 100 and the compensation method thereof that can maintain the luminance of the image to be the same despite the mobility characteristic change in the display period.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. , Separation, substitution, and alteration of the invention will be apparent to those skilled in the art. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: organic light emitting display
110: organic light emitting display panel
120: Data driver
130: gate driver
140: controller

Claims (12)

A display panel in which a plurality of data lines and a plurality of gate lines are arranged and a plurality of subpixels are arranged;
A data driver for driving the plurality of data lines;
A gate driver for driving the plurality of gate lines; And
And a controller for controlling the data driver and the gate driver,
Each of the sub-
A driving transistor for driving the organic light emitting diode; and a storage capacitor electrically connected between a first node and a second node of the driving transistor,
Further comprising a sensing unit sensing a voltage of a first node of the driving transistor and outputting a digital mobility sensing value for the sensed voltage in a mobility sensing period of the driving transistor,
The sensing unit includes:
Sensing the voltage of the first node of the driving transistor to output the nth mobility sensing value during the nth mobility sensing period of the driving transistor,
Sensing the voltage at the first node of the driving transistor and outputting the (n + 1) -th mobility sensing value during the (n + 1) -th mobility sensing period of the driving transistor,
The controller comprising:
Wherein the nth mobility compensation value is calculated from the nth mobility sensing value, and the n + 1 mobility sensing value sensed in the nth + 1 mobility sensing interval has a predetermined ratio according to the mobility characteristic, M + 1 mobility sensing data on the basis of the calculated nth mobility compensation value and outputs the data for the n + 1 mobility sensing period of the driving transistor based on the calculated nth mobility compensation value, And calculates an n + 1 mobility compensation value. The method according to claim 1,
And the (n + 1) -th mobility sensing value sensed in the (n + 1) -th mobility sensing period has a constant ratio that linearly increases according to mobility characteristics. 3. The method of claim 2,
The controller comprising:
And compensates the image data of the subpixel displaying the image based on the calculated n + 1 mobility compensation value, and outputs the compensated image data to the display section. The method of claim 3,
Wherein the subpixel has the same luminance depending on mobility characteristics in the display period. The method according to claim 1,
The controller comprising:
M + 1 mobility sensing data on the basis of the modified n-th mobility compensation value by multiplying the calculated n-th mobility compensation value by a coefficient for optimizing mobility compensation,
The coefficient for optimizing the mobility compensation may be obtained by optimizing the mobility compensation used so that the (n + 1) -th mobility sensing value sensed in the (n + 1) Wherein the organic light emitting display device has a value smaller than a coefficient to be used. The method according to claim 1,
The controller comprising:
Stored mobility sensing value having a predetermined ratio according to mobility characteristics and the nth mobility sensing value, and if the mth sensing value is not identical to the nth mobility sensing value, calculating a corrected nth mobility compensation value from the nth mobility sensing value, And generates the (n + 1) -th mobility sensing data based on the corrected n-th mobility compensation value. Generating data for mobility sensing for sensing the mobility of the driving transistor in the sub-pixel;
Outputting the mobility sensing data to a data driver;
Receiving a mobility sensing value corresponding to the mobility sensing result of the driving transistor in the sub-pixel using the mobility sensing data;
Calculating a mobility compensation value based on the mobility sensing value; And
And updating the mobility compensation value previously stored in the memory with the calculated mobility compensation value,
In the step of generating the mobility sensing data, the mobility sensing data, which is sensed in the mobility sensing period based on the previously calculated mobility compensation value, Of the organic light emitting display device. 8. The method of claim 7,
Wherein the mobility sensing value sensed in the mobility sensing interval has a constant rate that linearly increases with mobility characteristics. 9. The method of claim 8,
Compensating the image data of the subpixel displaying an image based on the calculated mobility compensation value, and outputting the compensated image data to the display section. 10. The method of claim 9,
Wherein the subpixel has the same luminance depending on mobility characteristics in the display period. 8. The method of claim 7,
In the step of generating the data for sensing the mobility,
Wherein the mobility compensating value is previously multiplied by a coefficient for optimizing mobility compensation to generate the mobility sensing data based on the mobility compensation value,
Wherein the coefficient for optimizing the mobility compensation is a value that is smaller than a coefficient for optimizing the mobility compensation used so that the mobility sensing value sensed in the mobility sensing interval has the same ratio according to the mobility characteristic A method of compensating an organic light emitting display. 8. The method of claim 7,
Further comprising the step of comparing the pre-stored target mobility sensing value having a certain ratio according to the mobility characteristic to the previously calculated mobility sensing value,
In the step of generating the data for sensing the mobility,
Calculating a corrected mobility compensation value from the previously calculated mobility sensing value if the target mobility sensing value does not match the previously calculated mobility sensing value, A method of compensating an organic light emitting display device for generating sensing data.

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