KR20170073771A - Organic light emitting display panel, organic light emitting display device and method for driving the organic light emitting display device - Google Patents

Abstract

The present invention relates to an organic light emitting diode (OLED) display panel, an organic light emitting diode (OLED) display, and a method of driving the OLED display. A compensating method for determining a compensating voltage for compensating for a decrease in luminance due to deterioration of an organic light emitting diode is provided. When the output data voltage corresponds to a low gradation, a compensation gain is calculated based on an initial luminance of the organic light emitting diode When the output data voltage corresponds to a high gradation, the compensation gain is calculated based on the luminance set lower than the initial luminance of the organic light emitting diode so that the driving light intensity due to the luminance degradation compensation is minimized while the organic light emitting diode exhibits the maximum initial luminance do.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting display panel, an organic light emitting display, and a method of driving the organic light emitting display device. [0002] The present invention relates to an organic light emitting display panel,

The present invention relates to an organic light emitting display panel, an organic light emitting display, and a method of driving the organic light emitting display.

BACKGROUND ART [0002] Organic light emitting displays (OLEDs), which have been popular as display devices in recent years, have advantages of high response speed, high contrast ratio, luminous efficiency, luminance and viewing angle by using an organic light emitting diode (OLED)

The OLED display includes an OLED display panel having a plurality of gate lines and a plurality of data lines and a plurality of subpixels arranged in a region where gate lines and data lines cross each other, A data driver for supplying a data voltage to a plurality of data lines, a timing controller for controlling driving of a gate driver and a data driver, and the like, and the sub-pixel includes an organic light emitting diode (OLED) and an organic light emitting diode OLED ").

In such an OLED display device, each of circuit elements such as an organic light emitting diode (OLED) and a driving transistor included in each subpixel has a unique characteristic value (e.g., threshold voltage, mobility, etc.). Degradation proceeds according to the driving time of the organic light emitting display, and the characteristic value thereof can be changed.

For example, the driving transistor may deteriorate according to driving time, and characteristic values such as a threshold voltage and a mobility may change. A change in the characteristic value causes a luminance deviation between the subpixels, and the luminance uniformity of the organic light- Can be omitted.

Further, as the deterioration of the organic light emitting diode (OLED) proceeds, the overall luminance of the organic light emitting display panel is lowered.

In order to prevent degradation of luminance due to deterioration of the organic light emitting diode (OLED), the degree of deterioration of the organic light emitting diode (OLED) is sensed and the data voltage is increased according to the degree of deterioration, .

At this time, when compensating for the degraded luminance based on the initial luminance of the organic light emitting diode OLED in compensating the deterioration of the organic light emitting diode OLED, the stress of the organic light emitting diode OLED increases, And there is a problem that the compensation voltage margin may be insufficient due to the limit of the voltage outputted from the data driver.

Accordingly, it is necessary to compensate for the decrease in brightness based on the luminance lower than the initial luminance of the organic light emitting diode (OLED). However, since this follows the luminance lower than the initial luminance of the organic light emitting diode (OLED) There is a problem that sufficient compensation can not be obtained for the deterioration of the OLED.

It is an object of the present embodiments to provide an organic light emitting display panel, an organic light emitting display, and a method of driving the organic light emitting display, which compensate for a decrease in luminance due to deterioration of the organic light emitting diode (OLED).

It is an object of the present embodiments to provide an organic light emitting display panel, an organic light emitting display device, and an organic light emitting display device capable of sufficiently compensating for a reduction in luminance due to deterioration of an organic light emitting diode (OLED) without increasing the stress of the organic light emitting diode And a method of driving the display device.

It is an object of the present invention to provide an organic light emitting display panel, an organic light emitting display, and a method of driving the organic light emitting display, which can maintain initial brightness in a general screen output in an organic light emitting display panel.

One embodiment includes a plurality of gate lines, a plurality of data lines, and a plurality of sub-pixels arranged in a region where the gate lines and the data lines cross each other and including a driving transistor for driving the organic light emitting diodes and the organic light emitting diodes A gate driver for driving a plurality of gate lines, a data driver for driving the plurality of data lines, and a timing controller for controlling driving of the gate driver and the data driver, And determines a compensation voltage for compensating for a decrease in luminance due to deterioration of the organic light emitting diode according to the target luminance set for each period of the data voltage output by the data driver .

In this organic light emitting diode display, the timing controller can determine the compensation voltage by setting the initial luminance of the organic light emitting diode to the target luminance or the luminance set lower than the initial luminance as the target luminance for each interval of the data voltage outputted by the data driver If the data voltage output by the data driver is less than the predetermined voltage, the compensation voltage is determined with the initial luminance of the organic light emitting diode as the target luminance. If the data voltage outputted by the data driver exceeds the predetermined voltage, It is possible to determine the compensation voltage according to the target luminance set lower.

In this organic light emitting display, the period of the data voltage for setting the target luminance may be set based on the difference between the data voltage output by the data driver and the maximum output voltage, and may be divided according to the gray level corresponding to the data voltage have.

In this organic light emitting diode display, the timing controller may obtain the deterioration information of the organic light emitting diode, compare the obtained deterioration information with the information of the predetermined lookup table to set the compensation gain, and determine the compensation voltage based on the set compensation gain have.

According to another embodiment of the present invention, there is provided an organic light emitting diode (OLED) display device, comprising: obtaining deterioration information of an organic light emitting diode; setting a compensation gain according to a deterioration information of the obtained organic light emitting diode and a target luminance set for each period of an output data voltage; And applying a compensation voltage to the data voltage, wherein the step of setting the compensation gain sets the initial luminance of the organic light emitting diode to the target luminance if the output data voltage is not more than a predetermined voltage, And setting the luminance lower than the initial luminance to the target luminance when the predetermined voltage is exceeded.

Another embodiment of the present invention is directed to a liquid crystal display device including a plurality of gate lines arranged in one direction, a plurality of data lines arranged to cross the gate lines, and a plurality of data lines arranged in a region where the gate lines and the data lines cross each other and driving the organic light emitting diodes and the organic light emitting diodes And a data line to which a compensating voltage determined based on the deterioration information of the organic light emitting diode and the target luminance set for each interval of the data voltage supplied to the data line is supplied, The organic light emitting display panel can be provided.

According to the embodiments, in the organic light emitting display panel, when a screen output of a full screen luminance or less is outputted, the luminance degradation due to deterioration of the organic light emitting diode OLED is compensated based on the initial luminance of the organic light emitting diode OLED, So that the screen displayed through the display panel can maintain the initial luminance.

According to the embodiments, when the screen between the full screen luminance and the peak luminance is outputted from the organic light emitting display panel, deterioration of the organic light emitting diode OLED according to the target luminance set lower than the initial luminance of the organic light emitting diode OLED So that it is possible to prevent the stress of the organic light emitting diode OLED from being increased due to the luminance compensation.

FIG. 1 is a diagram showing a schematic configuration of an organic light emitting display according to the present embodiments.
2 is a diagram illustrating an example of a sub-pixel structure of an OLED display according to an exemplary embodiment of the present invention.
3 is a diagram illustrating an example of a subpixel structure and a subpixel characteristic value sensing structure of the organic light emitting display according to the present embodiments.
4 is a diagram illustrating an example of luminance degradation according to driving time of the organic light emitting display according to the present embodiments.
5 is a diagram illustrating an example of a configuration for calculating a compensation gain for compensating for deterioration of an organic light emitting diode of an organic light emitting display according to the present embodiments.
FIGS. 6 and 7 are diagrams illustrating examples of target luminance as a reference for calculation of the compensation gain of the organic light emitting diode of the organic light emitting diode display according to the present embodiments.
FIGS. 8 and 9 are views illustrating exemplary compensation voltages by the compensation gain of the organic light emitting diode of the organic light emitting diode display according to the present embodiments. Referring to FIG.
10 is a flowchart illustrating a method of driving an OLED display according to an exemplary embodiment of the present invention.

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 shows a schematic configuration of an OLED display 100 according to the present embodiments.

1, the OLED display 100 includes a plurality of gate lines GL and a plurality of data lines DL, a gate line GL and a data line DL, An organic light emitting diode (OLED) display panel 110 including a plurality of subpixels SP disposed in the intersecting region, a gate driver 120 driving a plurality of gate lines GL, a plurality of data lines DL, And a timing controller 140 (T-CON) for controlling the gate driver 120 and the data driver 130. The timing controller 140 controls the gate driver 120 and the data driver 130,

The gate driver 120 sequentially drives the plurality of gate lines GL by sequentially supplying scan signals to the plurality of gate lines GL.

The gate driver 120 sequentially supplies a scan signal of an ON voltage or an OFF voltage to the plurality of gate lines GL in accordance with the control of the timing controller 140, Respectively.

The gate driver 120 may be located on one side or both sides of the organic light emitting display panel 110 according to the driving method.

In addition, the gate driver 120 may include one or more gate driver integrated circuits.

Each gate driver integrated circuit 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) method, (Gate In Panel) type and may be directly disposed on the organic light emitting display panel 110. The organic light emitting display panel 110 may be integrated with the organic light emitting display panel 110 or may be implemented as a chip on film (COF) method mounted on a film connected to the organic light emitting display panel 110.

The data driver 130 drives the plurality of data lines DL by supplying data voltages to the plurality of data lines DL.

When the specific gate line GL is opened, the data driver 130 converts the image data received from the timing controller 140 into analog data voltages and supplies the data voltages to the plurality of data lines DL, .

The data driver 130 may include at least one source driver integrated circuit to drive a plurality of data lines DL.

Each source driver integrated circuit 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) 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. [

In addition, each source driver integrated circuit may be implemented by a chip on film (COF) method. In this case, one end of each source driver integrated circuit is bonded to at least one source printed circuit board, and the other end is bonded to the organic light emitting display panel 110.

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

The timing 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 130, and outputs the converted image data And controls the data driving at a proper time according to the scan.

The timing controller 140 outputs various timing signals including a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, an input data enable (DE) signal, a clock signal CLK, (E.g., a host system).

The timing controller 140 may switch the input video data inputted from the outside according to the data signal format used by the data driver 130 and output the converted video data to the gate driver 120 and the data driver 130 A timing signal such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, an input data enable signal DE and a clock signal CLK to generate various control signals, (120) and the data driver (130).

For example, in order to control the gate driver 120, the timing 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 120. 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.

The timing controller 140 includes a source start pulse SSP, a source sampling clock SSC, a source output enable signal SOE, Output enable (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 130. 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 130.

The timing controller 140 is connected to a source printed circuit board to which a source driver integrated circuit is bonded and a control printed circuit (not shown) connected via a connection medium such as a flexible flat cable (FFC) or a flexible printed circuit And may be disposed on a substrate (Control Printed Circuit Board).

A power controller (not shown) for controlling various voltages or currents to supply or supply various voltages or currents to the organic light emitting display panel 110, the gate driver 120, the data driver 130, . These power controllers are also referred to as power management integrated circuits.

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

For example, in the organic light emitting display panel 110, each subpixel SP is composed of circuit elements such as a driving transistor (DRT) for driving the organic light emitting diode OLED and 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 a providing function, a design method, and the like.

2 shows an example of the sub-pixel (SP) structure of the organic light emitting diode display 100 according to the present embodiments.

2, each of the sub-pixels SP includes an organic light emitting diode OLED, a driving transistor DRT for driving the organic light emitting diode OLED, And a sensing transistor SENT which 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 A switching transistor SWT electrically connected between a second node N2 of the driving transistor DRT and a data line DL supplying a data voltage Vdata; And a storage capacitor Cstg electrically connected between the first node N1 and the second node N2.

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

The driving transistor DRT supplies a driving current to the organic light emitting diode OLED to drive 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 sensing transistor SENT may be turned on by a gate signal to apply the reference voltage Vref to the first node N1 of the driving transistor DRT.

In addition, the sensing transistor SENT may be utilized as a voltage sensing path for the first node N1 of the driving transistor DRT when turned on.

The switching transistor SWT transfers the data voltage Vdata supplied through the data line DL to the second node N2 of the driving transistor DRT when the switching transistor SWT is turned on by the gate signal.

At this time, the sensing transistor SENT and the switching transistor SWT may be connected to different gate lines GL so that the sensing transistor SENT and the switching transistor SWT may be separately controlled to be turned on and off or may be connected to the same gate line GL to be controlled.

The storage capacitor Cstg is electrically connected between the first node N1 and the second node N2 of the driving transistor DRT and supplies a data voltage Vdata corresponding to the video signal voltage or a voltage corresponding thereto You can keep it for one frame time.

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.

A change in the characteristic value of the circuit element causes a luminance change of the corresponding sub-pixel SP, and a difference in characteristic value between the circuit elements due to a difference in degree of deterioration between the circuit elements generates a luminance deviation between the sub- The luminance uniformity of the panel 110 may be lowered.

Here, the characteristic value of the circuit element includes the threshold voltage and the mobility of the driving transistor DRT and may include the threshold voltage of the organic light emitting diode OLED.

The OLED display 100 according to the present embodiment includes a sensing function for sensing a characteristic value variation between subpixels SP or a characteristic value deviation between each subpixel SP, Can be provided.

FIG. 3 shows an example of a sub-pixel (SP) structure and a compensation circuit of the organic light emitting diode display 100 according to the present embodiments.

3, the OLED display 100 according to the present embodiment includes a sensing unit 310, a compensation unit 320, a memory 330, and a driving unit 330 for sensing and compensating the characteristic value of the subpixel SP. A reference voltage switch SPRE and a sampling switch SAMP.

The sensing unit 310 senses a characteristic value of the sub-pixel SP or a voltage for sensing the change, converts the sensed voltage into a digital value, and outputs sensed data including the sensed sensed value.

Here, the characteristic value of the subpixel SP means the threshold voltage and the mobility of the driving transistor DRT and the threshold voltage of the organic light emitting diode OLED, and the sensing data is in a low voltage differential signaling (LVDS) data format .

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, and in some cases, it may be disposed outside the source driver integrated circuit.

The compensation unit 320 performs a compensation process for compensating for the characteristic value deviation between the subpixels SP by sensing the characteristic value or the change of the subpixel SP using the sensing data output from the sensing unit 310. [

The compensation unit 320 may be included in the timing controller 140 and may be disposed outside the timing controller 140 in some cases.

The memory 330 may store the sensing data output from the sensing unit 310 and may store the compensation value calculated by the compensating unit 320 based on the sensing data.

The reference voltage switch SPRE controls the supply of the reference voltage Vref to the reference voltage line RVL and the sampling switch SAMP controls the supply of the reference voltage Vref to the reference voltage line RVL in order to sense the voltage for sensing the characteristic value of the sub- And controls the connection between the voltage line RVL and the sensing unit 310.

When the reference voltage switch SPRE is turned on, the reference voltage Vref is supplied to the reference voltage line RVL. The reference voltage Vref supplied to the reference voltage line RVL may be applied to the first node N1 of the driving transistor DRT through the sensing transistor SENT which is turned on.

On the other hand, when the voltage of the first node N1 of the driving transistor DRT becomes a voltage state reflecting the characteristic value of the subpixel SP, a reference potential that can be equal to the first node N1 of the driving transistor DRT The voltage of the voltage line RVL may also be a voltage state reflecting the characteristic value of the subpixel SP. At this time, the line capacitor formed on the reference voltage line RVL may be charged with a voltage reflecting the characteristic value of the subpixel SP.

That is, when the sensing transistor SENT is turned on, the voltage of the first node N1 of the driving transistor DRT is lower than the voltage of the reference voltage line RVL and the voltage of the line RVL formed on the reference voltage line RVL. The voltage charged in the capacitor may be the same.

When the voltage of the first node N1 of the driving transistor DRT becomes a voltage state reflecting the characteristic value of the sub pixel SP, the sampling switch SAMP is turned on, (RVL) can be connected.

Accordingly, the sensing unit 310 senses the voltage of the reference voltage line RVL in a voltage state reflecting the characteristic value of the sub-pixel SP. Here, the reference voltage line RVL may be referred to as a "sensing line SL ".

That is, the sensing unit 310 senses the voltage of the first node N1 of the driving transistor DRT.

The voltage sensed by the sensing unit 310 may be a voltage value including a threshold voltage Vth or a threshold voltage change DELTA Vth of the driving transistor DRT in the case of threshold voltage sensing for the driving transistor DRT.

The voltage sensed by the sensing unit 310 may be a voltage value for sensing the mobility of the driving transistor DRT in the case of mobility sensing for the driving transistor DRT.

The voltage sensed by the sensing unit 310 may be a voltage that reflects a threshold voltage, which is a characteristic value of the organic light emitting diode OLED.

As described above, as the driving time of the organic light emitting display 100 increases, the driving transistor DRT deteriorates in the characteristic value of the driving transistor DRT. In addition, as the driving time of the organic light emitting diode OLT increases, A characteristic value deviation of the organic light emitting diode (OLED) due to deterioration may also occur.

When the OLED display 100 is driven for a long time, the organic light emitting diode OLED of each subpixel SP may be deteriorated due to driving stress, resulting in a screen abnormal phenomenon such as afterimage.

In order to understand the degree of deterioration of the organic light emitting diode OLED, the threshold voltage Vth_OLED of the organic light emitting diode OLED may be sensed to compensate for deterioration.

For example, when a current flows through the organic light emitting diode OLED, a voltage corresponding to the threshold voltage Vth_OLED is applied to the organic light emitting diode OLED. The current flowing in the driving transistor DRT varies according to the voltage applied to the organic light emitting diode OLED, and the voltage applied to the organic light emitting diode OLED can be sensed.

The degradation of the organic light emitting diode (OLED) is compensated by adjusting the data voltage applied to each subpixel SP according to the degree of deterioration of the organic light emitting diode (OLED) based on the sensed voltage, Can be performed.

Alternatively, the degree of deterioration of the organic light emitting diode OLED may be estimated according to the driving time of the OLED display 100.

FIG. 4 is a graph showing the luminance drop of the organic light emitting diode OLED according to the driving time of the OLED display 100 according to the present embodiments.

Referring to FIG. 4, it can be seen that the initial luminance of the organic light emitting diode OLED is 100%, and the luminance of the organic light emitting diode OLED decreases as the driving time of the organic light emitting display 100 increases.

Therefore, the degree of deterioration of the organic light emitting diode (OLED) may be determined on the basis of the value sensed by the sensing unit 310, and the degree of deterioration may be estimated according to the driving time of the organic light emitting display 100.

When the deterioration degree of the organic light emitting diode (OLED) is grasped, a compensation gain for compensating for the luminance degradation due to deterioration of the organic light emitting diode (OLED) can be calculated by using a lookup table having a luminance value to be adjusted according to deterioration have.

FIG. 5 shows an example of a configuration for calculating a compensation gain for compensating for a luminance drop due to deterioration of the organic light emitting diode OLED of the organic light emitting diode display 100 according to the present embodiments.

5, the timing controller 140 calculates the compensation gain using the average of the driving time of the OLED display 100 or the deterioration information of the organic light emitting diode OLED sensed by the sensing unit 310 Can be calculated.

The timing controller 140 compares the information of the lookup table in which the luminance adjustment value corresponding to the driving time of the OLED display 100 or the deterioration information average of the organic light emitting diode OLED is set with the driving time or the deterioration information average It is possible to calculate the luminance adjustment value for compensating for the decrease in luminance of the organic light emitting diode (OLED).

At this time, the luminance adjustment value may be calculated based on the target luminance set in the lookup table, and the target luminance may be the initial luminance of the organic light emitting diode OLED or the luminance set lower than the initial luminance.

That is, the timing controller 140 determines the degree of deterioration of the organic light emitting diode (OLED) using the driving time and the average deterioration information of the organic light emitting diode (OLED), compares the detected deterioration degree with the predetermined target luminance The luminance adjustment value is calculated and the compensation gain can be calculated according to the calculated luminance adjustment value.

The timing controller 140 may apply a compensation voltage generated by using compensation gain to the data voltage output through the data driver 130 to output the data voltage.

The timing controller 140 may multiply the data voltage by the compensation gain to output the data voltage reflecting the compensation value according to the degree of deterioration of the organic light emitting diode OLED or may calculate the compensation voltage using the data voltage and the compensation gain And a voltage obtained by adding the calculated compensation voltage to the data voltage may be output as the data voltage.

As described above, the timing controller 140 calculates the compensation gain for compensating for the decrease in luminance of the organic light emitting diode OLED according to the target luminance set in the lookup table in the process of calculating the compensation gain. Hereinafter, A method of setting the target luminance will be described.

FIGS. 6 and 7 show examples of the target luminance in the compensation gain calculation for compensating for the decrease in luminance of the organic light emitting diode OLED of the organic light emitting diode display 100 according to the present embodiments.

Referring to FIG. 6, the compensation gain may be calculated based on the initial luminance of the organic light emitting diode (OLED) in the calculation of the compensation gain for compensating for the luminance drop due to deterioration of the organic light emitting diode (OLED).

For example, the timing controller 140 determines the deterioration degree of the organic light emitting diode OLED based on driving time of the OLED display 100 or deterioration information sensed by the sensing unit 310.

Compares the degree of deterioration of the organic light emitting diode (OLED) with the initial luminance set in the lookup table, calculates a luminance adjustment value for compensating for the difference from the initial luminance, and calculates a compensation gain based on the calculated luminance adjustment value.

When the initial luminance of the organic light emitting diode OLED is set as the target luminance to compensate for the decrease in the luminance of the organic light emitting diode OLED, the OLED display panel 110 can maintain the initial luminance constant, There is a problem that the driving stress of the organic light emitting diode (OLED) is increased by performing compensation according to the initial luminance, so that the deterioration of the organic light emitting diode (OLED) is accelerated and the service life is shortened.

Further, when the data voltage (driving voltage) for displaying an image is high due to the limit of the output voltage of the data driver 130, a voltage (compensation voltage) for compensating the data voltage is not sufficiently secured.

Here, the compensation voltage may include a voltage for compensating for a characteristic value deviation of the driving transistor DRT, a voltage for compensating a luminance drop of the organic light emitting diode OLED, and the like.

Therefore, as shown in FIG. 6, the deterioration luminance set lower than the initial luminance of the organic light emitting diode (OLED) can be set as the target luminance, so that the luminance degradation of the organic light emitting diode (OLED) can be compensated.

In this case, the driving stress of the organic light emitting diode (OLED) due to the compensation of the luminance degradation of the organic light emitting diode (OLED) may be reduced, but sufficient luminance compensation can not be performed.

The present embodiments provide a way to compensate for the luminance drop due to deterioration of the organic light emitting diode (OLED) without increasing the driving stress of the organic light emitting diode (OLED).

FIG. 7 is a graph illustrating an example of a target luminance serving as a reference in calculating a compensation gain for compensating for a decrease in luminance of the organic light emitting diode (OLED) of the OLED display 100 according to the present embodiments.

Referring to FIG. 7, in compensating the luminance degradation due to the deterioration of the organic light emitting diode (OLED), the luminance degradation of the organic light emitting diode (OLED) can be compensated based on the target luminance set differently for each data voltage interval .

The timing controller 140 uses the driving time of the organic light emitting diode OLED or the deterioration information of the organic light emitting diode OLED sensed by the sensing unit 310 to determine the degree of deterioration of the organic light emitting diode OLED .

When the degree of deterioration of the organic light emitting diode (OLED) is recognized, the degree of deterioration is compared with the target luminance to calculate the luminance adjustment value, and the compensation gain is calculated according to the calculated luminance adjustment value.

At this time, in comparing the degree of deterioration of the organic light emitting diode (OLED) with the target luminance, it is possible to compare the target luminance set for each period of the data voltage outputted by the data driver 130 with the degree of deterioration of the organic light emitting diode OLED .

That is, the target luminance is set differently for each interval of the data voltage outputted by the data driver 130, the luminance adjustment value is calculated based on the target luminance corresponding to the output data voltage, and the compensation gain is calculated.

The period of the data voltage can be divided according to the gradation corresponding to the data voltage, and the OLED display panel 110 can display the data voltage for displaying the luminance in the full screen state and the data voltage representing the luminance in the peak state The target luminance can be set differently. Here, the luminance of the full screen state may be 150nit and the luminance of the peak state may be 500nit, and the data voltage corresponding to the luminance of the full screen state may be 5V and the data voltage corresponding to the luminance of the peak state may be 9V.

For example, when the data voltage is equal to or lower than a voltage (for example, 5 V) representing a luminance in a full screen state (e.g., 150 nit), the initial luminance of the organic light emitting diode OLED is set to a target luminance, The compensation gain for compensating for the luminance drop can be calculated.

If the data voltage is less than or equal to the full screen state, the driving voltage at the output voltage of the data driver 130 is low, and a margin for the compensation voltage can be sufficiently secured.

Further, in the case of displaying an image of a full screen state or less, the driving stress of the organic light emitting diode OLED is not large even if the organic light emitting diode OLED is compensated based on the initial luminance, so that deterioration of the organic light emitting diode OLED is accelerated It does not.

Therefore, if the data voltage is lower than the voltage representing the luminance in the full screen state, the driving stress of the organic light emitting diode OLED is compensated by compensating the luminance drop of the organic light emitting diode OLED based on the initial luminance of the organic light emitting diode OLED So that the initial luminance of the organic light emitting diode (OLED) can be maintained.

When the data voltage corresponds to a voltage (for example, 5V to 9V) representing a luminance in a full state (for example, 150nit) to a luminance in a peak state (for example, about 500nit), the initial luminance of the organic light emitting diode OLED And calculates a compensation gain for compensating for a decrease in luminance of the organic light emitting diode (OLED), with the luminance set at a low level as a target luminance.

If the data voltage exceeds the full screen state and compensation is performed based on the initial luminance of the organic light emitting diode OLED, deterioration can be accelerated by increasing driving stress of the organic light emitting diode OLED.

Therefore, when the data voltage exceeds the full-screen state, the luminance degradation of the organic light emitting diode OLED is compensated based on the target luminance set lower than the initial luminance of the organic light emitting diode OLED, The luminance lowering is compensated but the driving stress of the organic light emitting diode OLED due to the compensation of the luminance lowering can be reduced.

The interval of the data voltage that is the reference of the target luminance setting can be set based on the difference between the maximum output voltage of the data driver 130 and the data voltage output by the data driver 130. [

For example, assuming that the maximum output voltage of the data driver 130 is 15V, if the data voltage is 5V, the difference is 10V, and if the data voltage is 9V, the difference is 6V. Therefore, if the data voltage is 5V or less, the difference becomes 10V or more, and therefore, a margin for compensating for the decrease in luminance can be sufficiently secured.

Accordingly, if the difference between the data voltage and the maximum output voltage of the data driver 130 is equal to or greater than a predetermined value (for example, 10 V), the initial luminance of the organic light emitting diode OLED is set to the target luminance, The luminance lower than the initial luminance can be set to the target luminance.

That is, by setting the target luminance differently depending on whether or not the compensation voltage margin is secured, the luminance degradation is compensated according to the initial luminance in the data voltage interval in which the compensation voltage margin for compensating for the luminance reduction is ensured, It is also possible to compensate for the lowering of the luminance according to the lower luminance.

The timing controller 140 calculates the luminance adjustment value and the compensation gain based on the target luminance set for each section of the data voltage, applies the calculated compensation gain to the data voltage, and outputs the increased data voltage to thereby lower the luminance of the organic light emitting diode OLED So that it can be compensated for.

7, the target luminance is set according to the initial luminance of the organic light emitting diode OLED in a period in which the data voltage is equal to or lower than the voltage representing the luminance in the full screen state, and the data voltage is set to the luminance in the full screen state The compensation gain for compensating the luminance degradation of the organic light emitting diode OLED is calculated with the luminance set lower than the initial luminance of the organic light emitting diode OLED as the target luminance.

In addition, the target luminance for compensating the luminance degradation due to deterioration of the organic light emitting diode (OLED) may be set differently for each subpixel SP, that is, for each color.

There is a difference in light emission region due to the difference in the efficiency of the organic light emitting diode (OLED) for each color, and therefore, when the luminance degradation of the organic light emitting diode (OLED) is compensated based on the same target luminance, May increase.

Therefore, by setting the target luminance differently according to the data voltage and the sub-pixel SP and compensating for the luminance drop of the organic light emitting diode OLED, the organic light emitting diode OLED can maintain a constant luminance, Acceleration of deterioration due to driving stress can be prevented.

8 and 9 show examples of the configuration of the driving voltage and the compensation voltage at the output voltage of the data driver 130 of the OLED display 100 according to the present embodiments.

FIG. 8 shows a configuration of a driving voltage and a compensation voltage in the case of compensating for the luminance degradation of the organic light emitting diode OLED based on the deteriorated luminance shown in FIG.

Referring to FIG. 8, when the organic light emitting diode OLED exhibits the luminance in the peak state, it can be seen that there is no margin in the compensation voltage because the driving voltage is high. This is due to the compensation based on the degraded luminance of FIG. 6, and when the initial luminance of the organic light emitting diode OLED is taken as a reference, not only the margin of the compensation voltage is present but also the deterioration of the organic light emitting diode OLED due to compensation Can be accelerated.

When the luminance of the organic light emitting diode (OLED) is displayed in the full screen state, it can be seen that the compensating voltage corresponding to the luminance compensation is low by compensating based on the deteriorated luminance of FIG.

Here, when the luminance is in the full-screen state, although the margin of the compensation voltage is sufficient due to the low driving voltage, compensation according to the degraded luminance of FIG. 6 is not performed sufficiently.

FIG. 9 shows a configuration of a driving voltage and a compensation voltage in the case of compensating for the luminance drop of the organic light emitting diode OLED based on the target luminance shown in FIG.

9, when the luminance of the organic light emitting diode OLED is in a peak state, the compensation voltage is determined with the luminance lower than the initial luminance of the organic light emitting diode OLED as the target luminance, So that luminance compensation is performed within the output voltage and driving stress due to luminance compensation is not generated.

When the luminance of the organic light emitting diode OLED is in the full screen state, the compensation voltage is determined with the initial luminance of the organic light emitting diode OLED as the target luminance.

Accordingly, it can be confirmed that the voltage corresponding to the luminance compensation is increased in the compensation voltage. In the case of displaying a screen of a full screen or less, that is, a low gray scale by compensating the luminance drop based on the initial luminance of the organic light emitting diode OLED So that the initial luminance of the organic light emitting diode (OLED) can be maintained.

Further, at the time of outputting the low-gradation image, the driving stress of the organic light emitting diode OLED due to the luminance compensation is not large, so that the compensation for the luminance degradation of the organic light emitting diode OLED without affecting the deterioration of the organic light emitting diode OLED To be performed.

10 illustrates a driving method of the OLED display 100 according to the present embodiment.

Referring to FIG. 10, the organic light emitting diode display 100 according to the exemplary embodiments of the present invention includes a plurality of organic light emitting diodes (OLEDs) 100 based on the driving time of the organic light emitting diodes OLED or a value sensed by the sensing unit 310 Degradation information is acquired (S1000).

The present embodiments are characterized in that compensation is performed based on a target luminance set differently according to a data voltage outputted by the data driver 130 in compensating for the luminance degradation due to deterioration of the organic light emitting diode (OLED).

Therefore, it is checked whether the voltage output from the data driver 130 is lower than a predetermined voltage before the compensation of the luminance degradation of the organic light emitting diode OLED is performed (S1010).

Here, the predetermined voltage may correspond to a voltage (for example, 5V) indicating the luminance of the organic light emitting diode OLED in a full screen state (e.g., 150nit).

If the data voltage is less than the predetermined voltage, the compensation gain is calculated with the initial luminance of the organic light emitting diode OLED as the target luminance (S1020). If the data voltage exceeds the predetermined voltage, The compensation gain is calculated on the basis of the lower target luminance (S1030).

That is, the target luminance for compensating the luminance degradation is set differently according to the interval of the data voltage in consideration of the driving stress due to the luminance degradation compensation and the margin of the compensation voltage at the output voltage of the data driver 130.

The compensation voltage is generated by the calculated compensation gain (S1040), and the data voltage to which the compensation voltage is applied is outputted (S1050) so that compensation for the luminance drop due to deterioration of the organic light emitting diode (OLED) can be performed.

According to the present exemplary embodiments, when the data voltage output by the data driver 130 corresponds to a low gray level, the brightness degradation due to the deterioration of the organic light emitting diode OLED is compensated based on the initial luminance of the organic light emitting diode OLED Thereby allowing the organic light emitting diode OLED to maintain the initial luminance without increasing the driving stress of the organic light emitting diode OLED.

In addition, if the data voltage output from the data driver 130 corresponds to a high gray level, the luminance lowering due to deterioration of the organic light emitting diode OLED is compensated based on the luminance set lower than the initial luminance of the organic light emitting diode OLED So that compensation for the luminance drop of the organic light emitting diode OLED within the output voltage of the data driver 130 can be performed without accelerating deterioration of the organic light emitting diode OLED.

Therefore, by compensating the luminance degradation differently according to the gradation represented by the organic light emitting diode OLED, the driving stress of the organic light emitting diode OLED is reduced, and the driving voltage of the organic light emitting diode OLED So that compensation for the luminance drop of the display device can be performed.

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 and scope of the invention as defined by the appended claims. The embodiments of the present invention are not intended to limit the scope of the present invention but to limit the scope of the present invention.

100: organic light emitting display device 110: organic light emitting display panel
120: gate driver 130: data driver
140: timing controller 310: sensing unit
320: compensation unit 330: memory

Claims (11)

An organic light emitting diode (OLED) display panel including a plurality of gate lines, a plurality of data lines, and an organic light emitting diode (OLED) display panel having a plurality of subpixels arranged in a region where the gate lines and the data lines intersect, the plurality of subpixels including an organic light emitting diode panel;
A gate driver for driving the plurality of gate lines;
A data driver for driving the plurality of data lines; And
And a timing controller for controlling driving of the gate driver and the data driver,
The timing controller includes:
Determining a compensation voltage for compensating for the luminance degradation due to the deterioration of the organic light emitting diode according to the target luminance set for each period of the data voltage outputted by the data driver and the deterioration information obtained by obtaining the deterioration information of the organic light emitting diode And sets an initial luminance of the organic light emitting diode to a target luminance and sets a luminance lower than the initial luminance to a target luminance in a remaining period of a data voltage interval output by the data driver.
The method according to claim 1,
The timing controller includes:
When the data voltage output by the data driver is equal to or less than a predetermined voltage, the compensation voltage is determined with the initial luminance of the organic light emitting diode as the target luminance, and when the data voltage output by the data driver exceeds a preset voltage And determines the compensation voltage according to a target luminance set lower than the initial luminance.
3. The method of claim 2,
Wherein the predetermined voltage is a data voltage representing a luminance of a full screen state of the organic light emitting display panel.
The method according to claim 1,
Wherein a period of the data voltage is set based on a difference between a data voltage output by the data driver and a maximum output voltage.
The method according to claim 1,
Wherein the data voltage section is divided according to a gray level corresponding to the data voltage.
The method according to claim 1,
The timing controller includes:
Wherein the compensation voltage is determined based on a period of a data voltage output by the data driver and a target luminance set according to the subpixel.
The method according to claim 1,
The timing controller includes:
And compares the obtained deterioration information with information of a predetermined look-up table to set a compensation gain, and determines the compensation voltage based on a set compensation gain.
Obtaining deterioration information of the organic light emitting diode;
Setting a compensation gain according to deterioration information of the obtained organic light emitting diode and a target luminance set for each interval of an output data voltage; And
Applying a compensation voltage to the data voltage according to the set compensation gain
And a driving method of the organic light emitting display device.
9. The method of claim 8,
Wherein the step of setting the compensation gain comprises:
Setting an initial luminance of the organic light emitting diode to a target luminance when the output data voltage is less than a predetermined voltage and setting a luminance lower than the initial luminance to a target luminance when the output data voltage exceeds a preset voltage And a driving method of the organic light emitting display device.
9. The method of claim 8,
Wherein the step of setting the compensation gain comprises:
And sets the compensation gain based on a difference between the luminance according to the obtained deterioration information and the set target luminance.
A plurality of gate lines arranged in one direction;
A plurality of data lines arranged to cross the gate lines; And
And a plurality of sub-pixels arranged in a region where the gate line and the data line cross each other and including an organic light emitting diode and a driving transistor for driving the organic light emitting diode,
Wherein the data line includes:
Wherein a data voltage to which a compensation voltage determined based on the target luminance set for each of the deterioration information of the organic light emitting diode and the data voltage supplied to the data line is supplied.

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