KR102443641B1 - 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 embodiments relate to an organic light emitting display panel, an organic light emitting display device, and a driving method of an organic light emitting display device, wherein deterioration information of an organic light emitting diode is obtained, and target luminance set for each section of the obtained deterioration information and output data voltage is applied. A compensation method is provided for determining a compensation voltage for compensating for luminance degradation due to deterioration of the organic light emitting diode based on the compensation method. When the output data voltage corresponds to a high gray scale, the compensation gain is calculated based on the luminance set lower than the initial luminance of the organic light emitting diode, so that the organic light emitting diode can display the initial luminance as much as possible while minimizing the driving stress caused by the luminance degradation compensation. do.

Description

An organic light emitting display panel, an organic light emitting display device, and a driving method of an organic light emitting display device

The present embodiments relate to an organic light emitting display panel, an organic light emitting display device, and a method of driving the organic light emitting display device.

The organic light emitting display device, which has recently been spotlighted as a display device, has advantages of fast response speed, high contrast ratio, luminous efficiency, luminance and viewing angle by using an organic light emitting diode (OLED) that emits light by itself.

The organic light emitting display device includes an organic light emitting display panel including a plurality of gate lines and a plurality of data lines and a plurality of sub-pixels disposed in a region where the gate lines and the data lines intersect, and driving the plurality of gate lines. and a gate driver, a data driver for supplying data voltages to a plurality of data lines, and a timing controller for controlling driving of the gate driver and the data driver. a driving transistor for driving the OLED).

In such an organic light emitting display device, circuit elements such as an organic light emitting diode (OLED) or a driving transistor included in each sub-pixel each have unique characteristic values (eg, threshold voltage, mobility, etc.). In addition, degradation may be progressed according to the driving time of the organic light emitting display device, and thus the characteristic value may be changed.

For example, the driving transistor deteriorates according to the driving time, so characteristic values such as threshold voltage and mobility may change. can make you fall

In addition, when the organic light emitting diode (OLED) is deteriorated, the overall luminance of the organic light emitting display panel is reduced.

In order to prevent the decrease in luminance due to deterioration of the organic light emitting diode (OLED), the organic light emitting diode (OLED) senses the degree of deterioration and increases the data voltage according to the degree of deterioration so that the organic light emitting diode display panel maintains a constant luminance. can

At this time, when compensating for the reduced luminance based on the initial luminance of the organic light emitting diode (OLED) in compensating for the deterioration of the organic light emitting diode (OLED), the stress of the organic light emitting diode (OLED) may increase and deterioration may be accelerated. Also, there is a problem that the compensation voltage margin may be insufficient due to the limit of the voltage output from the data driver.

Accordingly, there is no choice but to compensate for the decrease in luminance based on the luminance lower than the initial luminance of the organic light emitting diode (OLED), but this follows the lower luminance than the initial luminance of the organic light emitting diode (OLED). There is a problem in that sufficient compensation for deterioration of OLED) is not provided.

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

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

In an exemplary embodiment, a plurality of gate lines, a plurality of data lines, and an organic light emitting diode disposed in a region where the gate line and the data line intersect and including a plurality of subpixels including an organic light emitting diode and a driving transistor for driving the organic light emitting diode are disposed. A light emitting display panel comprising: a gate driver for driving a plurality of gate lines; a data driver for driving a plurality of data lines; and a timing controller for controlling driving of the gate driver and the data driver, the timing controller comprising: an organic light emitting diode An organic light emitting display device that acquires degradation information of , and determines a compensation voltage for compensating for luminance degradation due to degradation of the organic light emitting diode according to the acquired degradation information and target luminance set for each section of the data voltage output by the data driver. can provide

In such an organic light emitting display device, the timing controller may determine the compensation voltage by setting the initial luminance of the organic light emitting diode as the target luminance for each section of the data voltage output by the data driver or setting the luminance lower than the initial luminance as the target luminance, , when the data voltage output by the data driver is less than or equal to the preset voltage, the compensation voltage is determined by using the initial luminance of the organic light emitting diode as the target luminance, and when the data voltage output by the data driver exceeds the preset voltage, the initial luminance is higher than The compensation voltage may be determined according to the low target luminance.

In such an organic light emitting display device, the data voltage section 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 such an organic light emitting display device, the timing controller obtains deterioration information of the organic light emitting diode, compares the obtained deterioration information with information in a preset lookup table, sets a compensation gain, and determines a compensation voltage based on the set compensation gain. have.

Another embodiment includes the steps of: obtaining deterioration information of an organic light emitting diode; setting a compensation gain according to a target luminance set for each section of the obtained deterioration information of the organic light emitting diode and output data voltage; and applying a compensation voltage to the data voltage accordingly, and the step of setting the compensation gain includes setting the initial luminance of the organic light emitting diode to the target luminance when the output data voltage is less than or equal to a preset voltage, and the output data voltage is The method of driving an organic light emitting display device including setting a luminance lower than an initial luminance as a target luminance when the preset voltage is exceeded may be provided.

In another exemplary embodiment, a plurality of gate lines disposed in one direction, a plurality of data lines disposed to cross the gate line, and a region where the gate line and the data line intersect are disposed to drive the organic light emitting diode and the organic light emitting diode. a data voltage to which a compensation voltage determined based on the target luminance set for each section of the data voltage supplied to the data line and deterioration information of the organic light emitting diode is applied to the data line. An organic light emitting display panel can be provided.

According to the present exemplary embodiments, when the organic light emitting display panel outputs a screen having a full screen luminance or less, the organic light emitting diode (OLED) is compensated for by compensating for a decrease in luminance due to deterioration of the organic light emitting diode (OLED) based on the initial luminance of the organic light emitting diode (OLED). A screen displayed through the display panel may maintain initial luminance.

According to the present embodiments, when the organic light emitting display panel outputs a screen between the full screen luminance and the peak luminance, the organic light emitting diode (OLED) deteriorates according to a target luminance set lower than the initial luminance of the organic light emitting diode (OLED). By compensating for the decrease in luminance due to the luminance compensation, it is possible to prevent the stress of the organic light emitting diode (OLED) from increasing due to the luminance compensation.

1 is a diagram illustrating a schematic configuration of an organic light emitting diode display according to the present exemplary embodiment.
2 is a diagram illustrating an example of a sub-pixel structure of an organic light emitting diode display according to the present exemplary embodiment.
3 is a diagram illustrating an example of a sub-pixel structure and a sub-pixel characteristic value sensing structure of the organic light emitting diode display according to the present exemplary embodiments.
4 is a diagram illustrating an example of a decrease in luminance according to a driving time of the organic light emitting diode display according to the present exemplary 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 diode display according to the present exemplary embodiment.
6 and 7 are diagrams illustrating examples of target luminance as a reference for calculating a compensation gain of an organic light emitting diode of an organic light emitting diode display according to the present exemplary embodiment.
8 and 9 are diagrams illustrating examples of a compensation voltage by a compensation gain of an organic light emitting diode of an organic light emitting diode display according to the present exemplary embodiment.
10 is a flowchart illustrating a process of a method of driving an organic light emitting display device according to the present exemplary embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the nature, order, order, or number of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but other components may be interposed between each component. It will be understood that each component may be “interposed” or “connected”, “coupled” or “connected” through another component.

1 shows a schematic configuration of an organic light emitting diode display 100 according to the present exemplary embodiments.

Referring to FIG. 1 , in the organic light emitting diode display 100 according to the present exemplary embodiments, a plurality of gate lines GL and a plurality of data lines DL are disposed, and a gate line GL and a data line DL are disposed. The organic light emitting display panel 110 including a plurality of sub-pixels SP disposed in the intersecting region, a gate driver 120 driving a plurality of gate lines GL, and a plurality of data lines DL It includes a data driver 130 for supplying a data voltage to the , and a timing controller 140 (T-CON) for controlling 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 according to the control of the timing controller 140 to the plurality of gate lines GL. run sequentially.

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

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

Each gate driver integrated circuit 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) method, or It is implemented as a GIP (Gate In Panel) type and may be directly disposed on the organic light emitting display panel 110 . In addition, the organic light emitting display panel 110 may be integrated and disposed, or may be implemented in 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 a specific gate line GL is opened, the data driver 130 converts the image data received from the timing controller 140 into an analog data voltage and supplies it to the plurality of data lines DL. ) is driven

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

Each source driver integrated circuit 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) method, or It may be directly disposed on the organic light emitting display panel 110 , or may be integrated and disposed on the organic light emitting display panel 110 .

In addition, each source driver integrated circuit may be implemented in 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 driving of the gate driver 120 and the data driver 130 .

The timing controller 140 starts a scan according to the timing implemented in each frame, converts externally input image data to match the data signal format used by the data driver 130 , and outputs the converted image data. and controls the data drive at an appropriate time according to the scan.

The timing controller 140 includes various timing signals including a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, an input data enable (DE) signal, and a clock signal CLK together with input image data. are received from the outside (eg host system).

The timing controller 140 converts the input image data input from the outside to match the data signal format used by the data driver 130 and outputs the converted image data, as well as the gate driver 120 and the data driver 130 . ), the gate driver receives 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, and generates various control signals to control the gate driver. 120 and the data driver 130 .

For example, the timing controller 140 controls the gate driver 120 , a gate start pulse (GSP), a gate shift clock (GSC), and a gate output enable signal (GOE). : Outputs various gate control signals (GCS: Gate Control Signal) including Gate Output Enable).

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 shift timing of a scan signal (gate pulse). The gate output enable signal GOE specifies timing information of one or more gate driver integrated circuits.

In addition, the timing controller 140 controls the data driver 130 , a source start pulse (SSP), a source sampling clock (SSC), and a source output enable signal (SOE: Source). Output Enable) and output various data control signals (DCS: Data Control Signal).

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 that controls 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 a control printed circuit connected to the source printed circuit board to which the source driver integrated circuit is bonded through a connection medium such as a flexible flat cable (FFC) or a flexible printed circuit (FPC). It may be disposed on a control printed circuit board.

The control printed circuit board includes a power controller (not shown) for supplying various voltages or currents to the organic light emitting display panel 110 , the gate driver 120 , and the data driver 130 , or controlling various voltages or currents to be supplied. more can be placed. Such a power controller is also referred to as a Power Management Integrated Circuit.

Each subpixel SP disposed in the organic light emitting display panel 110 may include circuit elements such as transistors.

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

The type and number of circuit elements constituting each sub-pixel SP may be variously determined according to a provided function and a design method.

2 illustrates an example of a structure of a subpixel SP of the organic light emitting diode display 100 according to the present exemplary embodiments.

Referring to FIG. 2 , in the organic light emitting diode display 100 according to the present exemplary embodiments, each subpixel SP includes an organic light emitting diode OLED and a driving transistor DRT for driving the organic light emitting diode OLED. ) and a sensing transistor (SENT) electrically connected between the first node N1 of the driving transistor DRT and a reference voltage line (RVL) supplying a reference voltage (Vref). ) and a switching transistor (SWT) electrically connected between the second node N2 of the driving transistor DRT and the data line DL supplying the data voltage Vdata, and the driving transistor DRT It is configured to include a storage capacitor (Cstg: Storage Capacitor) electrically connected between the first node (N1) and the second node (N2) of the.

The organic light emitting diode (OLED) may include a first electrode (eg, an anode electrode or a cathode electrode), an organic layer, and a second electrode (eg, 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 a source node or a 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) that supplies the driving voltage EVDD, and may be a drain node or a source node.

The sensing transistor SENT may be turned on by the gate signal to apply the reference voltage Vref to the first node N1 of the driving transistor DRT.

Also, the sensing transistor SENT may be used as a voltage sensing path for the first node N1 of the driving transistor DRT when it is turned on.

When turned on by the gate signal, 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.

In this case, the sensing transistor SENT and the switching transistor SWT may be separately controlled on-off by being connected to different gate lines GL, or may be controlled by being connected to the same gate line GL.

The storage capacitor Cstg is electrically connected between the first node N1 and the second node N2 of the driving transistor DRT, and receives a data voltage Vdata corresponding to the image signal voltage or a voltage corresponding thereto. It can be maintained for one frame time.

Meanwhile, in the case of the organic light emitting diode display 100 according to the present exemplary embodiments, as the driving time of each sub-pixel SP increases, the circuit elements such as the organic light emitting diode (OLED) and the driving transistor (DRT) are reduced. Degradation may proceed.

Accordingly, unique characteristic values (eg, threshold voltage, mobility, etc.) of circuit elements such as organic light emitting diodes (OLEDs) and driving transistors (DRTs) may change.

The change in the characteristic value of the circuit element causes a change in the luminance of the corresponding sub-pixel SP, and the difference in the change in the characteristic value between the circuit elements due to the difference in the degree of deterioration between the circuit elements causes a luminance deviation between the sub-pixels SP and causes an organic light emitting display. The luminance uniformity of the panel 110 may be deteriorated.

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

The organic light emitting diode display 100 according to the present exemplary embodiments includes a sensing function for sensing a characteristic value change between sub-pixels SP or a characteristic value deviation between each sub-pixel SP, and a sub-pixel SP using the sensing result. It is possible to provide a compensation function for compensating for the characteristic value of .

3 illustrates an example of a subpixel SP structure and a compensation circuit of the organic light emitting diode display 100 according to the present exemplary embodiments.

Referring to FIG. 3 , the organic light emitting diode display 100 according to the present exemplary embodiments includes a sensing unit 310 , a compensator 320 , a memory 330 , and a sensing unit 310 , a compensator 320 , and a memory 330 to sense and compensate the characteristic values of the sub-pixels SP. It may include a reference voltage switch SPRE and a sampling switch SAMP.

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

Here, the characteristic value of the sub-pixel SP means the threshold voltage and mobility of the driving transistor DRT or the threshold voltage of the organic light emitting diode (OLED), and the sensing data may be in the LVDS (Low Voltage Differential Signaling) data format. can

The sensing unit 310 may be implemented by including at least one analog to digital converter (ADC). Each analog-to-digital converter (ADC) may be included in the source driver integrated circuit, and in some cases may be disposed outside the source driver integrated circuit.

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

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

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

The reference voltage switch SPRE controls whether the reference voltage Vref is supplied to the reference voltage line RVL, and the sampling switch SAMP senses a voltage for sensing the characteristic value of the subpixel SP. 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 turned-on sensing transistor SENT.

On the other hand, when the voltage of the first node N1 of the driving transistor DRT becomes a voltage state that reflects the characteristic value of the sub-pixel SP, a reference that may be equipotential with the first node N1 of the driving transistor DRT The voltage of the voltage line RVL may also be in a voltage state reflecting the characteristic value of the subpixel SP. In this case, a voltage reflecting the characteristic value of the sub-pixel SP may be charged in the line capacitor formed on the reference voltage line RVL.

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

When the voltage of the first node N1 of the driving transistor DRT reaches a voltage state reflecting the characteristic value of the sub-pixel SP, the sampling switch SAMP is turned on, and the sensing unit 310 and the reference voltage line (RVL) may be linked.

Accordingly, the sensing unit 310 senses the voltage of the reference voltage line RVL, which is a voltage state reflecting the characteristic value of the subpixel 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 ΔVth of the driving transistor DRT in the case of sensing the threshold voltage of the driving transistor DRT.

In addition, 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.

Also, the voltage sensed by the sensing unit 310 may be a voltage reflecting a threshold voltage, which is a characteristic value of the organic light emitting diode (OLED).

On the other hand, as described above, as the driving time of the organic light emitting diode display 100 increases, not only the characteristic value deviation of the driving transistor DRT due to deterioration of the driving transistor DRT occurs, but also the organic light emitting diode (OLED) Deviation of characteristic values of organic light emitting diodes (OLEDs) due to deterioration may also occur.

When the organic light emitting diode display 100 is driven for a long time, the organic light emitting diode (OLED) of each sub-pixel SP is deteriorated due to driving stress, which may cause screen abnormalities such as an afterimage.

In order to determine 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 and the deterioration may be compensated.

For example, when a current flows through the organic light emitting diode OLED, a voltage equal to the threshold voltage Vth_OLED is applied to the organic light emitting diode OLED. A current flowing through the driving transistor DRT may be different according to a voltage applied to the organic light emitting diode OLED, and the voltage applied to the organic light emitting diode OLED may be sensed.

Compensation for deterioration of the organic light emitting diode (OLED) by determining the degree of deterioration of the organic light emitting diode (OLED) based on the sensed voltage and adjusting the data voltage applied to each sub-pixel (SP) according to the detected degree of deterioration 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 organic light emitting diode display 100 .

4 is a graph illustrating a decrease in luminance of the organic light emitting diode (OLED) according to the driving time of the organic light emitting diode display 100 according to the present exemplary embodiment.

Referring to FIG. 4 , it can be seen that the initial luminance of the organic light emitting diode (OLED) is set to 100% and the luminance of the organic light emitting diode (OLED) is decreased as the driving time of the organic light emitting display device 100 is increased.

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

When the degree of deterioration of the organic light emitting diode (OLED) is determined, a compensation gain for compensating for the decrease in luminance due to deterioration of the organic light emitting diode (OLED) can be calculated using a lookup table in which the luminance value to be adjusted according to the deterioration is set. have.

5 is a diagram illustrating an example of a configuration for calculating a compensation gain for compensating for a decrease in luminance due to deterioration of the organic light emitting diode (OLED) of the organic light emitting diode display 100 according to the present exemplary embodiment.

Referring to FIG. 5 , the timing controller 140 calculates a compensation gain by using the driving time of the organic light emitting display device 100 or the average of deterioration information of the organic light emitting diode (OLED) sensed by the sensing unit 310 . can be calculated.

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

In this case, the luminance control value may be calculated based on the target luminance set in the lookup table, and the target luminance may be an initial luminance of the organic light emitting diode (OLED) or a 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 or the average of deterioration information of the organic light emitting diode (OLED), and compares the determined degree of deterioration with a preset target luminance. The brightness adjustment value is calculated, and a compensation gain may be calculated according to the calculated brightness adjustment value.

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

The timing controller 140 may output a data voltage to which a compensation value according to the degree of deterioration of the organic light emitting diode (OLED) is reflected by multiplying the data voltage by the compensation gain, and 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, in the process of calculating the compensation gain, the timing controller 140 calculates a 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. A method of setting the target luminance will be described.

6 and 7 illustrate examples of target luminance when calculating a compensation gain for compensating for a decrease in luminance of the organic light emitting diode (OLED) of the organic light emitting diode display 100 according to the present exemplary embodiments.

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

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

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

When compensating for the decrease in luminance of the organic light emitting diode (OLED) by setting the initial luminance of the organic light emitting diode (OLED) as the target luminance, there is an advantage in that the organic light emitting display panel 110 can maintain the initial luminance constant, Compensation according to the initial luminance increases driving stress of the organic light emitting diode (OLED), thereby accelerating deterioration of the organic light emitting diode (OLED) and shortening the lifespan.

Also, when the data voltage (driving voltage) for displaying an image is high due to the limitation of the output voltage of the data driver 130 , there is a problem in that the 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 for a decrease in luminance of the organic light emitting diode OLED, and the like.

Accordingly, as illustrated in FIG. 6 , the deterioration in luminance of the organic light emitting diode OLED may be compensated for by setting the deteriorated luminance lower than the initial luminance of the organic light emitting diode OLED as the target luminance.

In this case, although the driving stress of the organic light emitting diode (OLED) due to the compensation for luminance deterioration of the organic light emitting diode (OLED) may be reduced, there is a problem in that sufficient luminance compensation cannot be achieved.

The present embodiments provide a method capable of compensating for luminance degradation due to deterioration of the organic light emitting diode (OLED) without increasing the driving stress of the organic light emitting diode (OLED).

7 is a graph illustrating examples of target luminance as a reference when calculating a compensation gain for compensating for a decrease in luminance of the organic light emitting diode (OLED) of the organic light emitting diode display 100 according to the present exemplary embodiment.

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

The timing controller 140 detects the degree of deterioration of the organic light emitting diode (OLED) by using the driving time of the organic light emitting diode (OLED) or deterioration information of the organic light emitting diode (OLED) sensed by the sensing unit 310 . .

When the degree of deterioration of the organic light emitting diode (OLED) is determined, a luminance adjustment value is calculated by comparing the determined deterioration degree with the target luminance, and a compensation gain is calculated according to the calculated luminance adjustment value.

In this case, in comparing the degradation degree of the organic light emitting diode (OLED) with the target luminance, the target luminance set for each section of the data voltage output by the data driver 130 and the degree of degradation of the organic light emitting diode (OLED) may be compared. .

That is, the target luminance is set differently for each section of the data voltage output 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 section of the data voltage may be divided according to the gradation corresponding to the data voltage, based on the data voltage for displaying the luminance of the organic light emitting display panel 110 in the full-screen state and the data voltage indicating the luminance in the peak state. The target luminance can be set differently. Here, the luminance of the full screen state may be 150 nits and the luminance of the peak state may mean 500 nits, 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 less than or equal to a voltage (eg, 5V) representing the luminance (eg, 150 nit) of the full screen state, the initial luminance of the organic light emitting diode (OLED) is set as the target luminance. A compensation gain for compensating for luminance degradation may be calculated.

When 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, so that a margin for the compensation voltage may be sufficiently secured.

In addition, in the case of displaying an image of a full screen state or less, even if the organic light emitting diode (OLED) is compensated based on the initial luminance, the driving stress of the organic light emitting diode (OLED) is not large, so that the deterioration of the organic light emitting diode (OLED) is accelerated. doesn't happen

Therefore, if the data voltage is less than or equal to the voltage representing the luminance of the full screen state, the driving stress of the organic light emitting diode (OLED) is reduced by compensating for the decrease in luminance of the organic light emitting diode (OLED) based on the initial luminance of the organic light emitting diode (OLED). It is possible to maintain the initial luminance of the organic light emitting diode (OLED) without increasing it.

When the data voltage corresponds to a voltage (eg, 5V to 9V) that represents between the luminance of the full screen state (eg, 150 nit) and the luminance of the peak state (eg, 500 nit), the initial luminance of the organic light emitting diode (OLED) A compensation gain for compensating for a decrease in the luminance of the organic light emitting diode (OLED) is calculated by using the low luminance as the target luminance.

If compensation is performed based on the initial luminance of the organic light emitting diode (OLED) when the data voltage exceeds the full screen state, deterioration may be accelerated due to an increase in driving stress of the organic light emitting diode (OLED).

Accordingly, when the data voltage exceeds the full screen state, the reduction in luminance of the organic light emitting diode (OLED) is compensated for based on the target luminance set lower than the initial luminance of the organic light emitting diode (OLED). Although the luminance deterioration is compensated, the driving stress of the organic light emitting diode (OLED) due to the luminance deterioration compensation may be reduced.

Also, a section of the data voltage serving as a reference for setting the target luminance may be set based on a 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, when the data voltage is 5V, the difference becomes 10V, and when the data voltage is 9V, the difference becomes 6V. Therefore, if the data voltage is 5V or less, the difference becomes 10V or more, so that a margin for compensating for luminance degradation 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 certain value (eg, 10V), the initial luminance of the organic light emitting diode (OLED) is set as the target luminance, and the difference is smaller than the constant value. In this case, a luminance lower than the initial luminance may be set as the target luminance.

That is, by setting the target luminance differently depending on whether the compensation voltage margin is secured, the luminance decrease is compensated according to the initial luminance in the section of the data voltage in which the compensation voltage margin for luminance degradation compensation is secured, and in other sections, the luminance decrease is lower than the initial luminance. It is also possible to compensate for the decrease in luminance according to the low luminance.

The timing controller 140 calculates a luminance control value and a compensation gain based on the target luminance set for each section of the data voltage, and applies the calculated compensation gain to increase the data voltage and output, thereby lowering the luminance of the organic light emitting diode (OLED). to be compensated for.

That is, as shown in FIG. 7 , in the section in which the data voltage is equal to or less than the voltage representing the luminance of the full screen state, the target luminance is set according to the initial luminance of the organic light emitting diode (OLED), and the data voltage is the luminance of the full screen state. In the section in which the voltage indicates the excess luminance, a compensation gain for compensating for the decrease in luminance of the organic light emitting diode (OLED) is calculated by using a luminance set lower than the initial luminance of the organic light emitting diode (OLED) as a target luminance.

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

For each color, there may be a difference in the light emitting area due to the difference in the efficiency of the organic light emitting diode (OLED) for each color. may increase.

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

8 and 9 show examples of the configuration of a driving voltage and a compensation voltage in the output voltage of the data driver 130 of the organic light emitting diode display 100 according to the present exemplary embodiment.

FIG. 8 shows the configuration of a driving voltage and a compensation voltage when compensating for a decrease in luminance of an organic light emitting diode (OLED) based on the deteriorated luminance shown in FIG. 6 .

Referring to FIG. 8 , it can be seen that when the organic light emitting diode (OLED) exhibits the luminance of the peak state, the driving voltage is high and there is no margin in the compensation voltage. This is due to compensation based on the deterioration luminance of FIG. 6 , and when the initial luminance of the organic light emitting diode (OLED) is used as a reference, a margin of the compensation voltage does not exist, and deterioration of the organic light emitting diode (OLED) due to compensation does not exist. can be accelerated

When the luminance of the organic light emitting diode OLED is displayed in a full screen state, it can be seen that the compensation voltage corresponding to the luminance compensation is low as compensation is performed based on the deteriorated luminance of FIG. 6 .

Here, when the luminance of the full-screen state is displayed, the luminance compensation is not sufficiently achieved by compensating according to the deteriorated luminance of FIG. 6 even though the driving voltage is low and the compensation voltage margin is sufficient.

9 is a diagram illustrating a configuration of a driving voltage and a compensation voltage in the case of compensating for a decrease in luminance of an organic light emitting diode (OLED) based on the target luminance shown in FIG. 7 .

Referring to FIG. 9 , when the luminance of the organic light emitting diode (OLED) is in the peak state, the compensation voltage is determined by setting the luminance lower than the initial luminance of the organic light emitting diode (OLED) as the target luminance. It performs luminance compensation within the output voltage and prevents driving stress caused by luminance compensation.

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

Therefore, it can be confirmed that the voltage corresponding to the luminance compensation among the compensation voltages is increased, and when a screen of a full screen or less, that is, a low gray scale is displayed, by compensating for the luminance decrease based on the initial luminance of the organic light emitting diode (OLED). It allows the initial luminance of the organic light emitting diode (OLED) to be maintained.

In addition, when the low grayscale image is output, the driving stress of the organic light emitting diode (OLED) due to the luminance compensation is not large, so that the deterioration of the organic light emitting diode (OLED) is not affected and the luminance decrease of the organic light emitting diode (OLED) is compensated. to allow this to be done.

10 illustrates a process of a method of driving the organic light emitting display device 100 according to the present exemplary embodiments.

Referring to FIG. 10 , in the organic light emitting diode display 100 according to the present exemplary embodiments, based on the driving time of the organic light emitting diode (OLED) or a value sensed by the sensing unit 310 , the organic light emitting diode (OLED) Deterioration information is obtained (S1000).

In the present exemplary embodiments, in compensating for luminance degradation due to deterioration of the organic light emitting diode (OLED), compensation is performed based on a target luminance set differently according to the data voltage output by the data driver 130 .

Therefore, before compensating for the decrease in luminance of the organic light emitting diode (OLED), it is checked whether the voltage output by the data driver 130 is equal to or less than a preset voltage ( S1010 ).

Here, the preset voltage may correspond to a voltage (eg, 5V) indicating the luminance (eg, 150 nit) of the organic light emitting diode (OLED) in a full screen state.

If the data voltage is less than the preset voltage, a compensation gain is calculated using the initial luminance of the OLED as the target luminance (S1020), and when the data voltage exceeds the preset voltage, the initial luminance of the organic light emitting diode (OLED) is higher than A compensation gain is calculated based on the low target luminance (S1030).

That is, the target luminance for luminance deterioration compensation is set differently for each section of the data voltage in consideration of the driving stress caused by the luminance deterioration compensation and the margin of the compensation voltage from the output voltage of the data driver 130 .

A compensation voltage is generated using the calculated compensation gain (S1040) and a data voltage to which the generated compensation voltage is applied is output (S1050) to compensate for luminance degradation due to deterioration of the organic light emitting diode (OLED).

According to the present exemplary embodiments, when the data voltage output by the data driver 130 corresponds to a low gray scale, a decrease in luminance due to deterioration of the organic light emitting diode OLED is compensated based on the initial luminance of the organic light emitting diode OLED. Accordingly, the organic light emitting diode (OLED) can maintain the initial luminance without increasing the driving stress of the organic light emitting diode (OLED).

In addition, when the data voltage output by the data driver 130 corresponds to a high gray scale, the luminance decrease due to deterioration of the OLED is compensated based on the luminance set lower than the initial luminance of the organic light emitting diode (OLED). , to compensate for the decrease in luminance of the organic light emitting diode (OLED) within the output voltage of the data driver 130 without accelerating the deterioration of the organic light emitting diode (OLED).

Accordingly, by differently performing luminance degradation compensation according to the gradation displayed by the organic light emitting diode (OLED), the driving stress of the organic light emitting diode (OLED) is reduced and the organic light emitting diode (OLED) is maximally within the output voltage of the data driver 130 . ) to compensate for the decrease in luminance.

The above description is merely illustrative of the technical idea of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. The embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but rather to explain, so the scope of the technical spirit of the present invention is not limited by these embodiments.

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 display in which a plurality of gate lines, a plurality of data lines, and a plurality of subpixels are disposed in a region where the gate lines and the data lines intersect, the plurality of subpixels including an organic light emitting diode and a driving transistor driving the organic light emitting diode panel;
a gate driver driving the plurality of gate lines;
a data driver driving the plurality of data lines; and
a timing controller for controlling driving of the gate driver and the data driver;
The timing controller is
Acquire the degradation information of the organic light emitting diode, and determine a compensation voltage for compensating for luminance degradation due to deterioration of the organic light emitting diode according to the acquired degradation information and the target luminance set for each section of the data voltage output by the data driver In some sections of the data voltage output by the data driver, the initial luminance of the organic light emitting diode is set as the target luminance, and in the remaining sections, a luminance lower than the initial luminance is set as the target luminance,
The slope of the target luminance in the partial section is different from the slope of the target luminance in the remaining section, and the target luminance in the remaining section increases when the data voltage increases.
According to claim 1,
The timing controller is
If the data voltage output by the data driver is less than or equal to a preset voltage, the compensation voltage is determined using the initial luminance of the organic light emitting diode as the target luminance, and when the data voltage output by the data driver exceeds the preset voltage, An organic light emitting display device for determining the compensation voltage according to a target luminance set to be lower than the initial luminance.
3. The method of claim 2,
The predetermined voltage is a data voltage representing the luminance of the full-screen state of the organic light emitting display panel.
According to claim 1,
The period of the data voltage is set based on a difference between the data voltage output by the data driver and the maximum output voltage.
According to claim 1,
The data voltage section is divided according to a gray level corresponding to the data voltage.
According to claim 1,
The timing controller is
The organic light emitting display device determines the compensation voltage based on a period of the data voltage output by the data driver and a target luminance set according to the sub-pixel.
According to claim 1,
The timing controller is
The organic light emitting diode display device obtains deterioration information of the organic light emitting diode, compares the obtained deterioration information with information of a preset lookup table, sets a compensation gain, and determines the compensation voltage based on the set compensation gain.
obtaining deterioration information of the organic light emitting diode;
setting a compensation gain according to the obtained deterioration information of the organic light emitting diode and target luminance set for each section of the output data voltage; and
applying a compensation voltage to the data voltage according to the set compensation gain;
The step of setting the compensation gain includes:
The initial luminance of the organic light emitting diode is set as a target luminance in a first period in which the output data voltage is equal to or less than a preset voltage, and is lower than the initial luminance in a second period in which the output data voltage exceeds the preset voltage. Set the luminance to the target luminance,
The slope of the target luminance in the first section is different from the slope of the target luminance in the second section, and the target luminance in the second section increases when the data voltage increases.
delete 9. The method of claim 8,
The step of setting the compensation gain includes:
A driving method of an organic light emitting display device for setting the compensation gain based on a difference between a luminance according to the acquired deterioration information and the set target luminance.
a plurality of gate lines arranged in one direction;
a plurality of data lines intersecting the gate lines; and
a plurality of sub-pixels disposed in a region where the gate line and the data line intersect and including an organic light emitting diode and a driving transistor for driving the organic light emitting diode;
The data line is
receiving a data voltage to which a compensation voltage determined based on the degradation information of the organic light emitting diode and a target luminance set for each section of the data voltage supplied to the data line is applied,
The slope of the target luminance set in the first period of the data voltage is different from the slope of the target luminance set in the second period of the data voltage, and in the second period, the target luminance increases as the data voltage increases. organic light emitting display panel.

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