KR102333385B1 - Organic light emitting display panel, organic light emitting display device, and the method for driving the organic light emitting display device - Google Patents

Abstract

The present embodiments relate to sensing and compensation technology in an organic light emitting display device, and when driving sensing for a characteristic value or a change in characteristic value for a circuit element in each sub-pixel, a sensing initialization time that is flexible and can take quite a long time The present invention relates to an organic light emitting display panel, an organic light emitting display device, and a driving method thereof, which can quickly and accurately sense a characteristic value or a change in a characteristic value of a circuit element in each sub-pixel, which is greatly shortened.

Description

Organic light emitting display panel, organic light emitting display device and driving method thereof

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

Recently, an organic light emitting display device, which has been in the spotlight as an organic light emitting display device, has advantages of fast response speed and high luminous efficiency, luminance, and viewing angle by using an organic light emitting diode (OLED) that emits light by itself.

In such an organic light emitting display device, sub-pixels including an organic light emitting diode and a driving transistor driving the same are arranged in a matrix form, and the brightness of the sub-pixels selected by a scan signal is controlled according to the gray level of data.

In such an organic light emitting display device, circuit elements such as an organic light emitting diode and a driving transistor in each sub-pixel each have unique characteristic values (eg, threshold voltage, mobility, etc.).

A luminance characteristic of a corresponding sub-pixel may vary according to a unique characteristic value of a circuit element in each sub-pixel.

However, as the driving time of the circuit element in each sub-pixel increases, deterioration may progress and thus a characteristic value may change, and the luminance characteristic of the corresponding sub-pixel may also change according to the change in the characteristic value.

In particular, when a characteristic value or characteristic value change between circuit elements is different from each other, a luminance deviation between sub-pixels may be induced, thereby deteriorating the luminance uniformity of the organic light emitting display panel.

Accordingly, a technology for sensing and compensating a characteristic value of a circuit element in each sub-pixel is being developed.

However, despite the compensation technology, the characteristic values of the circuit elements in each sub-pixel cannot be accurately sensed due to various factors, and thus accurate compensation is not performed.

An object of the present embodiments is to provide an organic light emitting display panel, an organic light emitting display device, and a driving method thereof, which enable accurate compensation by accurately and quickly sensing a characteristic value or a change in characteristic value of a circuit element in each sub-pixel. .

Another object of the present embodiments is to significantly shorten the sensing initialization time, which can be flexible and take quite a long time, through two sensing techniques when driving a sensing operation for a characteristic value or a characteristic value change for a circuit element in each sub-pixel. , to provide an organic light emitting display panel, an organic light emitting display device, and a driving method thereof, which can quickly sense a characteristic value or a change in a characteristic value of a circuit element in each sub-pixel.

Another object of the present embodiments is to significantly reduce the sensing initialization time, which can be flexible and take quite a long time, through two sensing techniques when driving a sensing operation for a characteristic value or a characteristic value change for a circuit element in each sub-pixel. , to provide an organic light emitting display panel, an organic light emitting display device, and a driving method thereof that enable accurate sensing through data offset processing.

In one aspect, the present exemplary embodiments include an organic light emitting display panel in which a plurality of data lines and a plurality of gate lines are disposed and a plurality of subpixels are disposed, and a data driver driving the plurality of data lines, and include a plurality of sub-pixels. Each pixel includes an organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first transistor connected between a first node of the driving transistor and a reference voltage line, and a second node connected between the second node of the driving transistor and a data line. 2 transistors and a storage capacitor connected between the first node and the second node of the driving transistor, and while the voltage of the reference voltage line or the voltage of the first node of the driving transistor increases, the voltage of the reference voltage line or The organic light emitting display device may further include a sensing unit configured to sense the voltage of the first node of the driving transistor twice.

In another aspect, the present exemplary embodiments provide an organic light emitting diode display including an organic light emitting diode display panel in which sub-pixels including an organic light emitting diode and a driving transistor for driving the organic light emitting diode are disposed, and a data driver for driving a data line. A driving method comprising: an initialization step of applying a reference voltage to a first node of a driving transistor and a first data voltage to a second node of the driving transistor; Provided is a method of driving an organic light emitting diode display, comprising the sensing step of sensing the voltage of the first node of the driving transistor or the voltage of another point electrically connected to the first node of the driving transistor twice while the voltage of the node is increased can do.

In another aspect, the present exemplary embodiments include an organic light emitting display panel in which a plurality of data lines and a plurality of gate lines are disposed and a plurality of subpixels are disposed, and a data driver driving the plurality of data lines, and a plurality of data lines are provided. Each subpixel includes an organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first transistor connected between a first node of the driving transistor and a reference voltage line, and a second node of the driving transistor and a data line connected between the data line. a second transistor and a storage capacitor connected between the first node and the second node of the driving transistor, and while the voltage of the reference voltage line or the voltage of the first node of the driving transistor increases, the data driver An organic light emitting display device that outputs a first data voltage to a line and outputs a second data voltage different from the first data voltage to a data line may be provided.

In another aspect, the present exemplary embodiments provide an organic light emitting display device including an organic light emitting diode display panel in which sub-pixels including an organic light emitting diode and a driving transistor for driving the organic light emitting diode are disposed, and a data driver for driving a data line. A driving method of a driving transistor comprising: applying a reference voltage to a first node of a driving transistor and applying a first data voltage to a second node of the driving transistor; floating the first node of the driving transistor; When the voltage of the first node of the driving transistor starts to rise according to the floating of the first node of It is possible to provide a driving method of an organic light emitting display device including the step of applying.

In another aspect, the present exemplary embodiments include a plurality of data lines disposed in a first direction, a plurality of gate lines disposed in a second direction, two or more reference voltage lines disposed in the first direction, and a matrix type. and a plurality of sub-pixels each including an organic light emitting diode and a driving transistor for driving the organic light emitting diode, and while the voltage of the first node of the driving transistor or the voltage of the reference voltage line increases, the data line includes: It is possible to provide an organic light emitting display panel in which a first data voltage is output and a second data voltage different from the first data voltage is output.

According to the present exemplary embodiments as described above, an organic light emitting display panel, an organic light emitting display device, and a driving method thereof that enable accurate compensation by accurately and quickly sensing a characteristic value or a change in characteristic value of a circuit element in each sub-pixel can provide

According to the present embodiments, when sensing driving a characteristic value or a characteristic value change for a circuit element in each sub-pixel, the sensing initialization time, which is flexible and can take quite a long time, is greatly shortened through two sensing techniques, It is possible to provide an organic light emitting display panel, an organic light emitting display device, and a driving method thereof that can quickly sense a characteristic value or a change in a characteristic value of a circuit element in each sub-pixel.

According to the present exemplary embodiments, when sensing a characteristic value or a characteristic value change for a circuit element in each sub-pixel, the sensing initialization time, which is flexible and takes quite a long time, is greatly reduced through two sensing techniques, while the data It is possible to provide an organic light emitting display panel, an organic light emitting display device, and a driving method thereof that enable accurate sensing through offset processing.

1 is a schematic system configuration diagram of an organic light emitting diode display according to example embodiments.
2A and 2B are exemplary views of a sub-pixel structure of an organic light emitting diode display according to example embodiments.
3 is a compensation circuit of the organic light emitting diode display according to the present exemplary embodiment.
4 is a view for explaining a threshold voltage sensing driving of the organic light emitting diode display according to the present exemplary embodiment.
5 is a diagram for explaining mobility sensing driving of the organic light emitting diode display according to the present exemplary embodiment.
6 is an exemplary diagram of a sensing section of the organic light emitting display device according to the present embodiments.
7 is a timing diagram for one-time sensing-based mobility sensing driving in the organic light emitting diode display according to the present embodiments.
8 is a timing diagram for a two-time sensing-based mobility sensing operation in the organic light emitting diode display according to the present exemplary embodiments.
FIG. 9 is a diagram illustrating four important states and voltage changes of major nodes in each of the two sensing-based mobility sensing operations in the organic light emitting diode display according to the present embodiments.
FIG. 10 is a diagram for explaining a mobility sensing method through two-time sensing-based mobility sensing driving in the organic light emitting display device according to the present exemplary embodiment.
11 is a flowchart illustrating a method of driving an organic light emitting diode display according to the present exemplary embodiment.
12 is another flowchart of a method of driving an organic light emitting diode display according to the present exemplary embodiment.
13 is a diagram illustrating an organic light emitting display panel according to the present exemplary embodiment.

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, if 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 essence, 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 is a schematic system configuration diagram of an organic light emitting display device 100 according to the present exemplary embodiment.

Referring to FIG. 1 , in the organic light emitting diode display 100 according to the present exemplary embodiments, a plurality of data lines DL and a plurality of gate lines GL are disposed, and a plurality of sub-pixels (SP) are provided. ), the data driver 120 driving the plurality of data lines DL, the gate driver 130 driving the plurality of gate lines GL, and the data driver 120 and a controller 140 controlling the gate driver 130 and the like.

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

The controller 140 starts scanning according to the timing implemented in each frame, and converts the input image data input from the outside according to the data signal format used by the data driver 120 to convert the converted image data DATA. output and control the data drive at an appropriate time according to the scan.

The controller 140 may be a timing controller used in a typical display technology or a control device that further performs other control functions including a timing controller.

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

The gate driver 130 sequentially drives the plurality of gate lines GL by sequentially supplying scan signals to the plurality of gate lines GL. Here, the gate driver 130 is a 'scan driver' Also called

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

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

Although the data driver 120 is located only on one side (eg, upper or lower side) of the organic light emitting display panel 110 in FIG. 1 , both sides of the organic light emitting display panel 110 (eg, according to a driving method, a panel design method, etc.) : It may be located on both the upper and lower sides).

Although the gate driver 130 is located only on one side (eg, left or right) of the organic light emitting display panel 110 in FIG. 1 , the gate driver 130 is located on both sides of the organic light emitting display panel 110 according to a driving method, a panel design method, etc. For example, it can be located on both the left and right side).

The above-described controller 140, along with the input image data, includes a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), an input data enable (DE: Data Enable) signal, a clock signal (CLK), including various Receive timing signals from the outside (eg host system).

The controller 140 converts the input image data input from the outside to match the data signal format used by the data driver 120 and outputs the converted image data, as well as the data driver 120 and the gate driver 130 . In order to control the data driver 120 and the gate driver 130 by receiving a timing signal such as a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), an input DE signal, and a clock signal to generate various control signals output as

For example, in order to control the gate driver 130 , the controller 140 includes a gate start pulse (GSP), a gate shift clock (GSC), and a gate output enable signal (GOE). Various gate control signals (GCS: Gate Control Signal) including gate output enable) are output.

Here, the gate start pulse GSP controls the operation start timing of one or more gate driver integrated circuits constituting the gate driver 130 . The gate shift clock GSC is a clock signal commonly input to one or more gate driver integrated circuits and controls 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 controller 140 controls the data driver 120 , 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 120 . 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 120 .

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

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

Each source driver integrated circuit SDIC may further include an analog-to-digital converter (ADC) in some cases.

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

Each gate driver integrated circuit GDIC may include a shift register, a level shifter, and the like.

Each subpixel 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 sub-pixel SP is composed of an organic light emitting diode (OLED) and circuit elements such as a driving transistor for driving the organic light emitting diode (OLED). .

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.

2A and 2B are exemplary views of a sub-pixel structure of the organic light emitting diode display 100 according to the present exemplary embodiment.

2A and 2B , in the organic light emitting diode display 100 according to the present exemplary embodiments, each sub-pixel drives an organic light emitting diode (OLED) and an organic light emitting diode (OLED). is electrically connected between a driving transistor (DRT) and a reference voltage line (RVL) supplying a reference voltage (Vref) and a first node (N1) of the driving transistor (DRT) a first transistor T1 to be used, a second transistor T2 electrically connected between the second node N2 of the driving transistor DRT and the data line DL for supplying the data voltage Vdata; and a storage capacitor (Cstg) electrically connected between the first node N1 and the second node N2 of the transistor DRT.

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

The first node N1 of the driving transistor DRT may be electrically connected to the first electrode of the organic light emitting diode OLED, and may be a source node or a drain node. The second node N2 of the driving transistor DRT may be electrically connected to a source node or a drain node of the second transistor T2 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 first transistor T1 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 first transistor T1 may be used as a voltage sensing path for the first node N1 of the driving transistor DRT when it is turned on.

When the second transistor T2 is turned on by the gate signal, it transfers the data voltage Vdata supplied through the data line DL to the second node N2 of the driving transistor DRT.

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

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

Meanwhile, as shown in FIG. 2A , on-off of the first transistor T1 and the second transistor T2 may be separately controlled.

That is, the first transistor T1 and the second transistor T2 have gate nodes connected to different gate lines GL1 and GL2, respectively, to receive different gate signals SCAN1 and SCAN2 so that on-off is controlled. can

Also, as shown in FIG. 2B , the first transistor T1 and the second transistor T2 may be controlled together.

That is, the first transistor T1 and the second transistor T2 may have their gate nodes connected to the same gate line GL, and receive the same gate signal SCAN to be controlled on/off together.

However, below, for convenience of explanation, the first transistor T1 and the second transistor T2 are supplied with the same gate signal SCAN through the same gate line GL so that on-off is controlled together. assume that

As shown in FIGS. 2A and 2B , each of the driving transistor DRT, the first transistor T1 , and the second transistor T2 may be implemented as an n-type, and in some cases, a p-type as well. could be

On the other hand, one reference voltage line RVL electrically connected to the drain node or the source node of the first transistor T1 may be disposed in one sub-pixel column, or in two or more sub-pixel columns. One of each may be arranged.

For example, if one pixel is composed of 4 sub-pixels (red sub-pixel, white sub-pixel, blue sub-pixel, and green sub-pixel), the reference voltage line RVL has 4 sub-pixel columns (red sub-pixel columns). , one white subpixel column, one blue subpixel column, and one green subpixel column).

On the other hand, 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 not applied. 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.

A change in the characteristic value of such a circuit element causes a change in luminance of a corresponding sub-pixel.

The degree of change in the characteristic value of the circuit element may be different for each circuit element due to a difference in the degree of deterioration between the circuit elements.

Accordingly, the difference in the degree of change in the characteristic value between the circuit elements due to the difference in the degree of deterioration between the circuit elements may cause a luminance deviation between sub-pixels, and may lead to a decrease in the luminance uniformity of the organic light emitting display panel 110 .

Here, the change in the characteristic value of the circuit element may be used in the same concept as the luminance change of the sub-pixel, and the deviation in the characteristic value between the circuit elements may be used in the same concept as the luminance deviation between the sub-pixels.

The above-described change in sub-pixel luminance and luminance deviation between sub-pixels may deteriorate the accuracy of the luminance expressive power of the sub-pixels or reduce the uniformity of the organic light emitting display panel 110, thereby degrading image quality.

Here, the characteristic value of the circuit element (hereinafter, also referred to as “sub-pixel characteristic value”) may include, for example, the threshold voltage and mobility of the driving transistor DRT, and in some cases, the organic light emitting diode (OLED). may include a threshold voltage of

The organic light emitting diode display 100 according to the present exemplary embodiments includes a sensing function for sensing (measuring) a change in a characteristic value of a sub-pixel or a deviation in a characteristic value between each sub-pixel, and a compensation function for compensating for a characteristic value of a sub-pixel using the sensing result can provide

Here, the characteristic value of the sub-pixel affects the luminance of the sub-pixel, and may include characteristic values of circuit elements (organic light emitting diode, driving transistor) in the sub-pixel.

The change in the characteristic value of the sub-pixel may include a change in the characteristic value of the driving transistor DRT and the change in the characteristic value of the organic light emitting diode OLED. It may include a characteristic value deviation between the diodes (OLED).

For example, the characteristic value of the sub-pixel may include 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 embodiments includes a sub-pixel structure ( FIG. 2A or FIG. 2B ) suitable for providing a sensing and compensation function for a sub-pixel characteristic value, and a sensing and compensation structure. Compensation circuit is included.

3 is a compensation circuit of the organic light emitting display device 100 according to the present exemplary embodiment.

Referring to FIG. 3 , the organic light emitting diode display 100 according to the present exemplary embodiments includes a sensing unit 310 that senses a change in a characteristic value of a sub-pixel and/or a deviation in a characteristic value between sub-pixels and outputs sensing data; It may include a memory 320 that stores data, a compensation unit 330 that performs a compensation process for compensating for a change in sub-pixel characteristic values and/or a deviation between sub-pixel characteristic values using the sensed data, and the like.

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 inside the source driver integrated circuit SDIC, and in some cases, may be included outside the source driver integrated circuit SDIC.

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

The sensing data output from the sensing unit 310 may be, for example, in a low voltage differential signaling (LVDS) data format.

Referring to FIG. 3 , in the organic light emitting diode display 100 according to the present exemplary embodiments, various switches SAMP, SPRE, and RPRE are connected to the reference voltage line RVL to control the sensing driving of the sub-pixels. can be connected

The sensing reference voltage switch SPRE is a switch connected between the supply node of the sensing reference voltage VpreS and the reference voltage line RVL, and the sensing reference voltage VpreS is connected to the reference voltage line RVL. A switch that controls what is supplied.

Here, the sensing reference voltage VpreS is an initialization voltage of the first node N1 of the driving transistor DRT during sensing driving, and is a type of the reference voltage Vref.

During sensing driving, the sensing reference voltage switch SPRE is turned on, and the sensing reference voltage VpreS is supplied to the reference voltage line RVL.

Accordingly, the first node N1 of the driving transistor DRT is initialized to the sensing reference voltage VpreS.

The sampling switch SAMP is a switch connected between the sensing unit 310 and the reference voltage line RVL.

When the sampling switch SAMP is turned on, the sensing unit 310 and the reference voltage line RVL are connected, and the sensing unit 310 may sense the voltage of the reference voltage line RVL.

Here, when the first transistor T1 is turned on, the reference voltage line RVL and the first node N1 of the driving transistor DRT may have an equipotential potential.

Accordingly, the voltage of the reference voltage line RVL may be the same as or similar to the voltage of the first node N1 of the driving transistor DRT.

The recovery reference voltage switch RPRE is a switch connected between the supply node of the recovery reference voltage VpreR and the reference voltage line RVL during a recovery process after sensing driving, and the recovery reference voltage VpreR is It is a switch that controls what is supplied to the reference voltage line RVL.

On the other hand, when the voltage of the first node N1 of the driving transistor DRT is in a voltage state reflecting the characteristic value of the sub-pixel according to the sensing driving, it is equal to the first node N1 of the driving transistor DRT. The voltage of the available reference voltage line RVL may also be in a voltage state reflecting the sub-pixel characteristic value. In this case, a voltage reflecting the characteristic value of the sub-pixel may be charged in the line capacitor formed on the reference voltage line RVL.

When the voltage of the first node N1 of the driving transistor DRT reaches a voltage state that reflects the characteristic value of the sub-pixel, the sampling switch SAMP is turned on, and the sensing unit 310 and the reference voltage line RVL are turned on. This can be connected

When the sensing unit 310 is connected to the reference voltage line RVL, the voltage of the reference voltage line RVL that reflects the voltage of the first node N1 of the driving transistor DRT (that is, the reference voltage line RVL) ) senses the voltage charged in the line capacitor), and converts the sensed voltage into a digital value to generate and output sensed data.

The voltage sensed by the sensing unit 310 is a voltage Vdata-Vth or Vdata-ΔVth including a threshold voltage Vth or a threshold voltage change ΔVth of the driving transistor DRT, or a voltage of the driving transistor DRT. It may be a voltage for sensing mobility or a voltage (Vdata-OLED_Vth or Vdata-ΔOLED_Vth) including a threshold voltage OLED_Vth or a threshold voltage change ΔOLED_Vth of the organic light emitting diode (OLED).

Hereinafter, threshold voltage sensing driving and mobility sensing driving of the driving transistor DRT will be briefly described with reference to FIGS. 4 and 5 .

However, hereinafter, for convenience of description, it is assumed that the first node N1 of the driving transistor DRT is a source node and the second node N2 of the driving transistor DRT is a gate node.

4 is a view for explaining a threshold voltage sensing driving of the organic light emitting diode display 100 according to the present exemplary embodiment.

Referring to FIG. 4 , when the threshold voltage sensing operation of the driving transistor DRT is performed, the first node N1 and the second node N2 of the driving transistor DRT respectively have a sensing reference voltage VpreS and a threshold voltage. It is initialized to the data voltage Vdata for sensing driving.

Thereafter, the sensing reference voltage switch SPRE is turned off, and the first node N1 of the driving transistor DRT is floated. Accordingly, the voltage of the first node N1 of the driving transistor DRT increases.

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

The saturated voltage of the first node N1 of the driving transistor DRT is the difference between the data voltage Vdata and the threshold voltage Vth (which may be a positive threshold voltage or a negative threshold voltage) of the driving transistor DRT or a data voltage It may correspond to the difference between (Vdata) and the threshold voltage change (ΔVth).

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

The voltage Vsense sensed by the sensing unit 410 is the voltage Vdata-Vth obtained by subtracting the threshold voltage Vth from the data voltage Vdata or the voltage obtained by subtracting the threshold voltage change ΔVth from the data voltage Vdata ( Vdata-ΔVth).

5 is a diagram for explaining mobility sensing driving of the organic light emitting diode display 500 according to the present exemplary embodiment.

Referring to FIG. 5 , when the mobility sensing is driven, the first node N1 and the second node N2 of the driving transistor DRT respectively have a sensing reference voltage VpreS and a mobility sensing driving data voltage Vdata. ) is initialized to

Thereafter, the sensing reference voltage switch SPRE is turned off, and the first node N1 of the driving transistor DRT is floated. Accordingly, the voltage of the first node N1 of the driving transistor DRT may increase.

At this time, the voltage rising rate (the amount of change in the voltage rising value with respect to time ΔV) represents the current capability of the driving transistor DRT, that is, the mobility.

Accordingly, as the driving transistor DRT has a large current capability (mobility), the voltage at the first node N1 of the driving transistor DRT rises more steeply.

The sensing unit 310 senses the increased voltage Vs of the first node N1 of the driving transistor DRT after the voltage rises for a predetermined period of time.

The difference between the voltage Vsense sensed by the sensing unit 310 and the reference voltage VpreS for sensing corresponds to the voltage change amount ΔV.

Referring to FIG. 3 , the sensing unit 310 senses a voltage for threshold voltage sensing or mobility sensing as the above-described threshold voltage sensing driving or mobility sensing driving proceeds, and receives the sensed voltage Vsense. It is converted into a digital value, and sensed data including the converted digital value is generated and output.

Referring to FIG. 3 , sensing data output from the sensing unit 310 may be stored in the memory 320 or provided to the compensator 330 .

Referring to FIG. 3 , the compensator 330 includes characteristic values (eg, threshold voltage, mobility) of a driving transistor DRT in a corresponding sub-pixel based on sensing data stored in the memory 320 or provided from the sensing unit 310 . Alternatively, a characteristic value change (eg, a threshold voltage change, a mobility change) of the driving transistor DRT may be identified, and a characteristic value compensation process may be performed.

Here, the change in the characteristic value of the driving transistor DRT may mean that the current sensed data is changed based on the previous sensed data or that the current sensed data is changed based on the reference sensed data.

Here, by comparing a characteristic value or a characteristic value change between the driving transistors DRT, a characteristic value deviation between the driving transistors DRT may be recognized.

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

The threshold voltage compensation process calculates a compensation value for compensating for a threshold voltage or a threshold voltage deviation (threshold voltage change), and stores the calculated compensation value in the memory 320 or the image data DATA as the calculated compensation value. It may include processing to change the .

The mobility compensation process calculates a compensation value for compensating for mobility or mobility deviation (mobility change), and stores the calculated compensation value in the memory 320 or the image data DATA as the calculated compensation value. It may include processing to change the .

Referring to FIG. 3 , the compensator 330 changes the image data DATA through threshold voltage compensation processing or mobility compensation processing to convert the changed image data DATA′ into the corresponding source driver integrated circuit in the data driver 120 . (SDIC) can be supplied.

Accordingly, the source driver integrated circuit SDIC converts the changed image data DATA' into the data voltage Vdata and supplies it to the corresponding sub-pixel, so that the sub-pixel characteristic compensation (threshold voltage compensation, mobility compensation) is actually performed. will be done

As such sub-pixel characteristic value compensation is performed, image quality can be improved by reducing or preventing a luminance deviation between sub-pixels.

6 is an exemplary diagram of a sensing section of the organic light emitting diode display 100 according to the present embodiments.

Referring to FIG. 6 , the organic light emitting diode display 100 according to the present exemplary embodiments may perform a sensing operation during an On-Sensing Period (ONS) after a power-on signal is generated.

In addition, the organic light emitting diode display 100 according to the present exemplary embodiments may perform a sensing operation during an OFF-Sensing Period (OFFS) after a power-off signal is generated.

In addition, the organic light emitting diode display 100 according to the present exemplary embodiments may perform a sensing operation for each Real Time Sensing Period (RTS) existing during image driving.

More specifically, based on the vertical synchronization signal Vsync, the blank time between the active times corresponding to the image driving time is allocated as the real-time sensing period RTS, and the sensing operation is performed each time. can proceed.

Meanwhile, the threshold voltage sensing for one sub-pixel takes a relatively long time compared to the mobility sensing for one sub-pixel.

Accordingly, as an example, the threshold voltage sensing may be performed in the off-sensing period OFFS, and the mobility sensing may be performed in each of the on-sensing period ONS and the real-time sensing period RTS.

As described above, since the threshold voltage sensing and the mobility sensing must be performed in a predetermined period (ONS, OFFS, and RTS), the sensing operation needs to proceed quickly.

In particular, in the case of the sensing operation performed in the on-sensing period (ONS) according to the generation of the power-on signal, it is necessary to rapidly perform the sensing operation in the on-sensing period (ONS) for rapid power-on processing and rapid image driving start. have.

In addition, when the sensing operation is performed for each real-time sensing interval (RTS) corresponding to the blank time between active times, since the sensing operation must be performed in a short blank time, the sensing operation for each real-time sensing interval (RTS) is performed quickly. A sensing driving method that can do this is required.

Hereinafter, a sensing driving method that allows the sensing operation to proceed as quickly as possible within a predetermined time, taking mobility sensing as an example, will be described.

7 is a timing diagram for one-time sensing-based mobility sensing driving in the organic light emitting diode display 100 according to the present exemplary embodiments.

Referring to FIG. 7 , the organic light emitting diode display 100 according to the present exemplary embodiments may perform mobility sensing in a sensing initialization step and a sensing step. However, it is assumed that the first node N1 of the driving transistor DRT is a source node and the second node N2 of the driving transistor DRT is a gate node.

Referring to FIG. 7 , in the sensing initialization step, the sensing reference voltage switch SPRE is turned on, and the sensing reference voltage VpreS is supplied to the reference voltage line RVL. In addition, the data voltage Vdata corresponding to the sensing data DATA is supplied to the data line DL. The gate signal SCAN applied to the gate nodes of the first transistor T1 and the second transistor T2 becomes a high level, and the first transistor T1 and the second transistor T2 are turned on.

Accordingly, in the sensing initialization step, the sensing reference voltage VpreS supplied to the reference voltage line RVL is applied to the first node N1 of the driving transistor DRT through the turned-on first transistor T1. ) is approved. The data voltage Vdata supplied to the data line DL is applied to the second node N2 of the driving transistor DRT through the turned-on second transistor T2 .

That is, in the sensing initialization step, the voltage Vs of the first node N1 of the driving transistor DRT is initialized to the sensing reference voltage VpreS, and the voltage of the second node N2 of the driving transistor DRT. (Vg) is initialized to the sensing data voltage (Vdata).

Referring to FIG. 7 , after the sensing initialization step, a sensing step is performed. In this sensing step, the sensing reference voltage switch SPRE is turned off.

Accordingly, the first node N1 of the driving transistor DRT floats, and the voltage Vs of the first node N1 of the driving transistor DRT increases.

At this time, the voltage Vs of the first node N1 of the driving transistor DRT rises with a constant slope.

In the sensing step, after a predetermined time elapses after the voltage Vs of the first node N1 of the driving transistor DRT rises, the sampling switch SAMP is turned on, and the reference voltage line RVL and the sensing unit 310 is connected.

Accordingly, the sensing unit 310 generates a reference voltage line RVL corresponding to a voltage at which the voltage Vs of the first node N1 of the driving transistor DRT increases for a predetermined time from the sensing reference voltage VpreS. sense the voltage of

Meanwhile, the amount of change (ΔV=Vsen-VpreS) of the voltage Vs of the first node N1 of the driving transistor DRT is proportional to the drain-source current Ids of the driving transistor DRT.

That is, the amount of change (ΔV=Vsen-VpreS) of the voltage Vs of the first node N1 of the driving transistor DRT is proportional to the mobility corresponding to the current capability of the driving transistor DRT.

The amount of change (ΔV=Vsen-VpreS) of the voltage Vs of the first node N1 of the driving transistor DRT can be confirmed based on the sensed voltage Vsen and a known reference voltage for sensing VpreS.

Meanwhile, after the sensing step, a recovery process including a recovery initialization step and a recovery step may be performed in order to prevent a phenomenon in which a subpixel row (line) in which the mobility sensing has been performed is displayed on the screen when the next image is driven.

In the recovery initialization step, the recovery reference voltage switch RPRE is turned on, and the recovery reference voltage VpreR is supplied to the reference voltage line RVL. A data voltage corresponding to the black data BLK is applied to the second node N2 of the driving transistor DRT through the data line DL.

In the recovery step, a data voltage corresponding to the recovery data REC is applied to the second node N2 of the driving transistor DRT through the data line DL.

On the other hand, when the mobility sensing operation is performed in the on-sensing period (ONS) after the generation of the power-on signal at the timing of FIG. 7 , the movement is performed in the on-sensing period (ONS) for quick power-on processing and rapid image driving start Also, the sensing operation needs to proceed quickly.

In addition, when the mobility sensing operation is performed for each real-time sensing period (RTS) corresponding to the blank time between the active times at the timing of FIG. 7, since the mobility sensing operation must be performed in a short blank time, the real-time sensing period ( The mobility sensing operation for each RTS) needs to be performed quickly.

Meanwhile, as described above, in the mobility sensing, after the first node N1 of the driving transistor DRT is initialized to the sensing reference voltage VpreS, the first node N1 of the driving transistor DRT is By increasing the voltage, the voltage increase amount ΔV according to the current capability of the driving transistor DRT is measured to sense the mobility of the driving transistor DRT.

Accordingly, in order to quickly and accurately sense the mobility of the driving transistor DRT, the first node N1 of the driving transistor DRT must be quickly and accurately initialized to the sensing reference voltage VpreS.

However, due to parasitic capacitors unavoidably present in the reference voltage line RVL, it takes a long time (Tinit) to initialize the voltage of the first node N1 of the driving transistor DRT to the sensing reference voltage VpreS. This can take

Accordingly, a lot of sensing time is required to sense the mobility of the driving transistor DRT.

If the period length of the sensing initialization step is determined, the voltage of the first node N1 of the driving transistor DRT within the predetermined initialization step period due to parasitic capacitors unavoidably present in the reference voltage line RVL. This sensing reference voltage (VpreS) may not be reached.

In this case, the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT is reduced, so that the sensing value may be reduced. Accordingly, accurate compensation may not be provided.

Also, in the sensing initialization step, the voltage of the reference voltage line RVL is not constant to the sensing reference voltage VpreS due to a coupling phenomenon due to the noise signal, and thus the sensing accuracy may be deteriorated.

Accordingly, in the present embodiments, the first node N1 of the driving transistor DRT is quickly and accurately initialized to the sensing reference voltage VpreS to shorten the sensing time for the characteristic value of the sub-pixel, and through this, the sub-pixel A two-time sensing-based sensing driving method capable of accurately sensing a characteristic value (or a characteristic value change) of a pixel is proposed.

Hereinafter, the sensing driving method based on the two-time sensing of the organic light emitting display device 100 according to the present exemplary embodiments will be described in more detail by taking mobility sensing as an example.

8 is a timing diagram for the two-time sensing-based mobility sensing driving in the organic light emitting diode display 100 according to the present exemplary embodiments.

Referring to FIG. 8 , the organic light emitting diode display 100 according to the present exemplary embodiments may perform sensing processing (sampling processing) twice in order to shorten the sensing initialization time Tinit.

Accordingly, the sensing initialization time Tinit is greatly shortened, and thus the overall mobility sensing time may be significantly shortened.

In addition, in order to shorten the sensing initialization time Tinit and prevent a decrease in sensing accuracy, at a certain point in time, a voltage difference (Vgs) between the second node N2 and the first node N1 of the driving transistor DRT. It is necessary to maintain

To this end, the organic light emitting diode display 100 according to the present exemplary embodiments performs data offset processing for maintaining the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT. can be performed.

Hereinafter, the schematically described two-time sensing-based driving method will be described in more detail.

Referring to FIG. 8 , the sensing reference voltage switch SPRE is briefly turned on and then turned off, the first node N1 of the driving transistor DRT is floated, and the voltage of the reference voltage line RVL is Alternatively, while the voltage of the first node N1 of the driving transistor DRT is rising, the sensing unit 310 may generate the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT. is sensed twice.

That is, the sensing reference voltage switch SPRE is briefly turned on and then turned off, so that the first node N1 of the driving transistor DRT is floated, so that the voltage of the reference voltage line RVL or the driving transistor ( While the voltage of the first node N1 of the DRT is rising, the sampling switch SAMP is turned on twice to connect the sensing unit 310 and the reference voltage line RVL twice.

As described above, while the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT is rising, the sensing unit 310 is configured to operate the voltage of the reference voltage line RVL or the driving transistor DRT. By sensing the voltage of the first node N1 of the transistor DRT twice, even if the first node N1 of the driving transistor DRT is not accurately initialized to the sensing reference voltage VpreS, the Based on the sensing voltage (the primary sensing voltage, the secondary sensing voltage) or the secondary sensing voltage, it is possible to accurately determine the voltage increase amount, thereby accurately determining the characteristic value (eg, mobility) of the driving transistor (DRT).

Meanwhile, while the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT is rising, the data driver 120 transfers the first sensing data DATA1 to the data line DL. ) while outputting the first data voltage Vdata1 corresponding to the second data voltage Vdata2 corresponding to the second sensing data DATA2 different from the first sensing data DATA1, that is, the first data A second data voltage Vdata2 different from the voltage Vdata1 may be output to the data line DL.

More specifically, the data driver 120 performs the first data before the sensing unit 310 first senses the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT. After outputting the voltage Vdata1 to the data line DL, the sensing unit 310 first senses the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT. A second data voltage Vdata2 different from the first data voltage Vdata1 may be output to the data line DL.

Here, the second data voltage Vdata2 is higher than the first data voltage Vdata1.

More specifically, the second data voltage Vdata2 is a voltage obtained by adding the offset voltage Voffset to the first data voltage Vdata1.

The offset voltage Voffset may be determined by the primary sensing voltage Vsen1 in which the sensing unit 310 first senses the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT. can

For example, the offset voltage Voffset may correspond to the difference Vsen1-VpresS between the primary sensing voltage Vsen1 and the sensing reference voltage VpreS.

Here, the sensing reference voltage VpreS is the voltage supplied to the reference voltage line RVL before the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT rises. am.

The controller 140 calculates the offset data Offset DATA based on the digital value of the primary sensing voltage Vsen1 sensed by the sensing unit 310 , and the offset data calculated in the first sensing data DATA1 . (Offset DATA) is added to generate the second sensing data DATA2 and supplied to the data driver 120 .

Here, changing the first sensing data DATA1 to the second sensing data DATA2 during the sensing step is referred to as “data offset processing”.

According to the data offset processing, while the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT rises, the data driver 120 transfers the first voltage to the data line DL. While outputting the first data voltage Vdata1 corresponding to the sensing data DATA1, the second data voltage Vdata2 corresponding to the second sensing data DATA2 different from the first sensing data DATA1; That is, the second data voltage Vdata2 different from the first data voltage Vdata1 may be output to the data line DL.

When the data driver 120 outputs the first data voltage Vdata1 to the data line DL, the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT is , when the data driver 120 outputs the second data voltage Vdata2 to the data line DL, the voltage difference between the second node N2 and the first node N1 of the driving transistor DRT corresponds to each other. can be

As described above, the second node N2 of the driving transistor DRT immediately after the first sensing and The voltage difference Vgs of the first node N1 may be equal to the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT when accurate sensing initialization is performed. have. Accordingly, it is possible to create a situation identical to that in which sensing (sampling) is performed once in spite of sensing (sampling) twice.

Below, the sensing time between the first sensing-based sensing driving method of FIG. 7 and the second sensing-based sensing driving method of FIG. 8 is compared. Here, the sensing time corresponds to the sum of the time Tinit required for the sensing initialization step and the time required for the sensing step.

First, briefly describing the mobility sensing method, the changed voltage of the first node N1 of the driving transistor DRT is sensed for a predetermined period of time, and before the sensed voltage Vsense and the voltage change occur. As the voltage of the first node N1 of the driving transistor DRT, the voltage difference (ΔV, that is, the voltage change amount) between the known sensing reference voltages VpreS is calculated and obtained, and the difference between the voltage change amount ΔV and the mobility is obtained. Mobility sensing is performed by determining the mobility of the driving transistor DRT according to predetermined relational characteristic information (eg, a correspondence table, etc.).

In view of the aforementioned mobility sensing method, for accurate mobility sensing, the voltage change amount ΔV of the first node N1 of the driving transistor DRT must be accurately calculated.

However, in the sensing initialization step, the voltage of the first node N1 of the driving transistor DRT is changed to the initialization voltage due to various factors (eg, various capacitor components such as a line capacitor on the organic light emitting display panel 110 ). If it is not correctly initialized to the corresponding sensing reference voltage VpreS, from the calculation of subtracting the known sensing reference voltage VpreS from the measured voltage Vsense of the first node N1 of the driving transistor DRT. The obtained voltage change amount may be different from the actual voltage change amount of the first node N1 of the driving transistor DRT, and mobility sensing accuracy is lowered to a different extent.

Therefore, in the case of one-time sensing-based sensing driving, for accurate mobility sensing, the voltage of the first node N1 of the driving transistor DRT is accurately initialized to the sensing reference voltage VpreS corresponding to the desired initialization voltage. It is absolutely necessary to wait a sufficient amount of time (which can be preset through experimental statistics) until

However, in the case of two-time sensing-based sensing driving, since the amount of voltage change of the first node N1 of the driving transistor DRT can be obtained using the primary sensing voltage and the secondary sensing voltage, the driving transistor DRT There is no need to wait until the voltage of the first node N1 is correctly initialized to the sensing reference voltage VpreS corresponding to the desired initialization voltage.

In other words, in the case of the second sensing-based sensing operation, the time Tinit set for the sensing initialization step is not relevant even if it is shorter than in the case of the first sensing-based sensing operation.

0). In some cases, as long as the voltage of the first node N1 of the driving transistor DRT can be lower than the voltage before the sensing initialization step, the sensing reference voltage VpreS is applied to the first node N1 of the driving transistor DRT. ), the sensing reference voltage VpreS may be supplied to the reference voltage line RVL, and then directly enter the sensing stage. In this case, the time required for the sensing initialization step may be short enough to be almost negligible (Tinit).

0).

As such, in the case of the sensing driving method based on the two-time sensing, compared to the case of the sensing driving method based on the sensing once, the sensing operation is driven by setting a shorter time (Tinit) for the sensing initialization step without degrading the sensing accuracy. , it is possible to reduce the sensing time (eg, the starting point of the sensing initialization stage to the second sampling time).

In addition, in the case of the two-time sensing-based sensing driving method, there is no need to wait until the voltage of the first node N1 of the driving transistor DRT is correctly initialized to the sensing reference voltage VpreS corresponding to the desired initialization voltage. Since there is no such thing, the degree of freedom for timing design of sensing driving may be increased.

FIG. 9 is a diagram illustrating four important states and voltage changes of main nodes in each state when the organic light emitting diode display 100 according to the present exemplary embodiments is driven twice by sensing-based mobility.

9 is a diagram illustrating data subjected to data offset processing immediately after a sensing initialization state, a primary sensing state, and a first sensing operation, in the organic light emitting display device 100 according to the present exemplary embodiments, when driving the sensing-based mobility sensing twice. In four important states including an offset state and a secondary sensing state, the voltage Vs of the first node N1 of the driving transistor DRT and the voltage Vg of the second node N2 of the driving transistor DRT ) is a diagram showing the change in

The sensing initialization state is a state in the sensing initialization stage, and the primary sensing state, the data offset state, and the secondary sensing state are three states in the sensing stage.

Referring to FIG. 9 , in the sensing initialization state, the voltage Vg of the second node N2 of the driving transistor DRT is the first data voltage Vdata1 and the first node N1 of the driving transistor DRT. A voltage (Vs) of is a reference voltage (VpreS) for sensing.

Here, the voltage Vs of the first node N1 of the driving transistor DRT may not reach the sensing reference voltage VpreS due to less initialization.

In the sensing initialization state, a voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT is Vdata1-VpreS.

Accordingly, in the sensing initialization state, the voltage Vg of the second node N2 of the driving transistor DRT, the voltage Vs of the first node N1 of the driving transistor DRT, and the driving transistor DRT A voltage difference Vgs between the second node N2 and the first node N1 of

Referring to FIG. 9 , in the primary sensing state, the voltage Vg of the second node N2 of the driving transistor DRT is the first data voltage Vdata1 and the first node N1 of the driving transistor DRT. ) voltage Vs is the primary sensing voltage Vsen1.

In the primary sensing state, a voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT is Vdata1-Vsen1.

Accordingly, in the primary sensing state, the voltage Vg of the second node N2 of the driving transistor DRT, the voltage Vs of the first node N1 of the driving transistor DRT, and the driving transistor DRT ), the voltage difference Vgs between the second node N2 and the first node N1 is expressed by Equation 2 below.

Referring to FIG. 9 , in the data offset state immediately after the first sensing, the voltage Vg of the second node N2 of the driving transistor DRT is the second data voltage Vdata2, and the first of the driving transistor DRT is The voltage Vs of the node N1 is the primary sensing voltage Vsen1.

In the data offset state immediately after the primary sensing, the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT is Vdata2-Vsen1.

Accordingly, in the data offset state immediately after the primary sensing, the voltage Vg of the second node N2 of the driving transistor DRT, the voltage Vs of the first node N1 of the driving transistor DRT, and the driving A voltage difference Vgs between the second node N2 and the first node N1 of the transistor DRT is expressed by Equation 3 below.

Here, the second data voltage Vdata2 is a voltage obtained by adding the offset voltage Voffset to the first data voltage Vdata1.

Considering this point, Equation 3 can be expressed again as Equation 4 below.

Meanwhile, the offset voltage Voffset corresponds to a voltage obtained by subtracting the sensing reference voltage VpreS from the primary sensing voltage Vsen1.

Considering this point, Equation 4 can be expressed again as Equation 5 below.

As shown in Equation 1, the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT in the sensing initialization state and the data offset state as in Equation 5 above Comparing the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT in It can be seen that the voltage difference (Vgs) of one node N1 is the same as Vdata1-VpreS.

Referring to FIG. 9 , in the secondary sensing state, the voltage Vg of the second node N2 of the driving transistor DRT is the second data voltage Vdata2=Vdata1+Voffset, and the voltage Vg of the driving transistor DRT is The voltage Vs of the first node N1 is the secondary sensing voltage Vsen2.

In the secondary sensing state, the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT is Vdata2-Vsen2 (= Vdata1+Voffset-Vsen2).

Accordingly, in the secondary sensing state, the voltage Vg of the second node N2 of the driving transistor DRT, the voltage Vs of the first node N1 of the driving transistor DRT, and the driving transistor DRT ), the voltage difference Vgs between the second node N2 and the first node N1 is expressed by Equation 6 below.

As described above, when the second sensing is completed, the characteristic value (eg, mobility, threshold voltage) of the driving transistor DRT may be sensed based on the second sensing result or the second sensing result.

As an example, a method of sensing the mobility of the driving transistor DRT based on the second sensing result or the secondary sensing result will be briefly described with reference to FIG. 10 .

FIG. 10 is a diagram for explaining a mobility sensing method through a two-time sensing-based mobility sensing driving in the organic light emitting display device 100 according to the present exemplary embodiments.

Referring to FIG. 10 , the sensing unit 310 may include a voltage of the reference voltage line RVL or a voltage of the first node N1 of the driving transistor DRT according to the secondary turn-on of the sampling switch SAMP. is secondarily sensed, and the second sensed voltage Vsen2, which is the second sensed voltage, is converted into a digital value and transmitted.

Accordingly, the compensator 330 is configured to generate the secondary sensing voltage Vsen2 corresponding to the digital value transmitted from the sensing unit 310 , that is, the sensing unit 310 is the voltage of the reference voltage line RVL or the driving transistor. Based on the secondary sensing voltage Vsen2 that is secondarily sensed by the voltage of the first node N1 of the DRT, a characteristic value (eg, mobility) of the driving transistor DRT is calculated, and the Characteristic value compensation processing (eg, mobility compensation processing) may be performed.

As a more specific example, the compensator 330 may generate a voltage increase amount (ΔV=Vsen2-Vsen1) of the first node N1 of the driving transistor DRT for a predetermined time Δt based on the secondary sensing voltage Vsen2. can be calculated to calculate the mobility of the driving transistor DRT.

Here, the voltage increase amount ΔV of the first node N1 of the driving transistor DRT may be the difference between the secondary sensing voltage Vsen2 and the primary sensing voltage Vsen1, or the secondary sensing voltage Vsen2. and the reference voltage for sensing VpreS.

As described above, comparing FIGS. 7 and 8 , through two sensing-based sensing driving, the sensing initialization time Tinit can be greatly shortened and accurate compensation processing can be performed through accurate sensing.

11 is a flowchart of a method of driving the organic light emitting display device 100 according to the present exemplary embodiments.

Referring to FIG. 11 , in the method of driving the organic light emitting diode display 100 according to the present exemplary embodiments, a reference voltage VpreS is applied to the first node N1 of the driving transistor DRT, and the driving transistor DRT is applied. ), an initialization step (S1110) of applying a first data voltage to the second node of the driving transistor (DRT), and floating the first node (N1) of the driving transistor (DRT) so that the voltage of the first node (N1) of the driving transistor (DRT) is During the rising, the voltage of the first node N1 of the driving transistor DRT or another point electrically connected to the first node N1 of the driving transistor DRT (eg, any point on the reference voltage line RVL) As such, the sensing step ( S1120 ) of sensing the voltage at the point where the line capacitor is formed) may be included twice.

When the driving method of the organic light emitting diode display 100 according to the above-described exemplary embodiments is used, while the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT is increased, By sensing the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT twice, the first node N1 of the driving transistor DRT is converted to the sensing reference voltage VpreS. Even if it is not correctly initialized, the amount of voltage increase is accurately determined based on the sensing voltage (primary sensing voltage, secondary sensing voltage) or secondary sensing voltage sensed twice, and the characteristic value (eg, mobility) of the driving transistor (DRT) ) can be accurately identified.

Referring to FIG. 11 , in the above-described sensing step S1120 , the voltage of the first node N1 of the driving transistor DRT or the voltage of another point electrically connected to the first node N1 of the driving transistor DRT A first sensing step (S1121) of first sensing the A secondary sensing step (S1125) of secondarily sensing the voltage of the first node N1 of the transistor DRT or the voltage of another point electrically connected to the first node N1 of the driving transistor DRT may be included (S1125). can

In the data offset step S1123 , the second data voltage Vdata2 offset from the first data voltage Vdata1 may be a voltage obtained by adding the offset voltage Voffset to the first data voltage Vdata1 .

As described above, as the sensing step S1120 proceeds to the first sensing step S1121 , the data offset step S1123 , and the second sensing step S1125 , the first node N1 of the driving transistor DRT Through data offset processing in consideration of the increase in the voltage Vs of It may be equal to the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT when . Accordingly, in spite of sensing (sampling) twice, it is possible to create the same situation as if sensing (sampling) was performed correctly once, thereby enabling accurate sensing while speeding up the sensing initialization speed.

Meanwhile, in the data offset step S1123 , the offset voltage Voffset added to the first data voltage Vdata1 is the voltage of the first node N1 of the driving transistor DRT or the offset voltage Voffset added to the first data voltage Vdata1 in the first sensing step S1121 . It may be a value determined by the primary sensing voltage Vsen1 that senses voltages at other points electrically connected to the first node N1 of the driving transistor DRT once.

As described above, after the offset voltage Voffset is determined based on the primary sensing voltage Vsen1, the second data voltage Vdata2 obtained by performing data offset processing based on this is used to determine the second data voltage of the driving transistor DRT. By increasing the voltage of the first node N1 , even in a situation in which the first node N1 of the driving transistor DRT is not correctly initialized to the sensing reference voltage VpreS, the first node N1 of the driving transistor DRT ) can be adaptively set to a reference voltage for determining the voltage increase amount (ΔV).

Accordingly, it is possible to quickly and accurately sense the mobility of the driving transistor DRT in any situation.

12 is another flowchart of a method of driving the organic light emitting display device 100 according to the present exemplary embodiments.

Referring to FIG. 12 , in the method of driving the organic light emitting display device 100 according to the present exemplary embodiments, a reference voltage VpreS is applied to the first node N1 of the driving transistor DRT, and the driving transistor DRT is applied. ) applying the first data voltage Vdata1 to the second node N2 ( S1210 ), floating the first node N1 of the driving transistor DRT ( S1220 ), and the driving transistor DRT ) when the voltage of the first node N1 of the driving transistor DRT starts to rise according to the floating of the first node N1 of The step of applying a second data voltage Vdata2 different from the first data voltage Vdata1 to the node N2 ( S1230 ) may be included.

When the driving method of the organic light emitting diode display 100 according to the above-described exemplary embodiments is used, while the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT is increased, In sensing the voltage of the reference voltage line RVL or the voltage of the first node N1 of the driving transistor DRT twice, through a data voltage change process, despite sensing (sampling) twice, once It enables accurate and rapid sensing under the same conditions as when sensing (sampling) was performed correctly.

Immediately after the second data voltage Vdata1 is applied in step S1230, the voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT is The voltage difference Vgs between the second node N2 and the first node N1 of the driving transistor DRT may be equal to the voltage difference Vgs before the node N1 floats.

Accordingly, in spite of sensing (sampling) twice, it is possible to create the same situation as when sensing (sampling) is performed once, and through this, it is possible to enable fast and accurate sensing.

The organic light emitting display device 100 and the organic light emitting display panel 110 used in the driving method according to the above-described embodiments will be briefly described.

13 is a diagram illustrating the organic light emitting display panel 110 according to the present exemplary embodiment.

Referring to FIG. 13 , the organic light emitting display panel 110 according to the present exemplary embodiments includes a plurality of data lines DL disposed in a first direction, a plurality of gate lines GL disposed in a second direction, and , two or more reference voltage lines RVL arranged in the first direction, and a plurality of matrix types each including an organic light emitting diode (OLED) and a driving transistor (DRT) for driving the organic light emitting diode (OLED). It includes a sub-pixel SP.

Referring to FIG. 13 , after the sensing initialization step, according to the floating of the first node N1 of the driving transistor DRT, the voltage of the first node N1 of the driving transistor DRT or the reference voltage line RVL While the voltage is rising, a first data voltage Vdata1 may be output to the data line DL and a second data voltage Vdata2 different from the first data voltage Vdata1 may be output.

As described above, it is possible to provide the organic light emitting display panel 110 capable of quickly and accurately sensing the characteristic value of the driving transistor DRT through sensing twice.

The above-mentioned second data voltage Vdata2 may be a voltage obtained by adding an offset voltage Voffset to the first data voltage Vdata1.

According to the present embodiments as described above, the organic light emitting display panel 110, the organic light emitting display device ( 100) and a driving method thereof.

According to the present embodiments, when the sensing operation for the characteristic value or the characteristic value change of the circuit element in each sub-pixel is driven, the sensing initialization time, which is flexible and can take quite a long time, is greatly shortened through two sensing techniques, It is possible to provide an organic light emitting display panel 110 , an organic light emitting display device 100 , and a driving method thereof that can quickly sense a characteristic value or a change in a characteristic value of a circuit element in each sub-pixel.

According to the present exemplary embodiments, when sensing a characteristic value or a characteristic value change for a circuit element in each sub-pixel, the sensing initialization time, which is flexible and takes quite a long time, is greatly reduced through two sensing techniques, while the data It is possible to provide the organic light emitting display panel 110 , the organic light emitting display device 100 , and a driving method thereof that enable accurate sensing through offset processing.

The above description and the accompanying drawings are merely illustrative of the technical spirit of the present invention, and those of ordinary skill in the art to which the present invention pertains can combine configurations within a range that does not depart from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

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

Claims (21)

an organic light emitting display panel in which a plurality of data lines and a plurality of gate lines are disposed and a plurality of subpixels are disposed; and
a data driver for driving the plurality of data lines;
Each of the plurality of sub-pixels,
An organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first transistor connected between the first node of the driving transistor and a reference voltage line, and a second connected between the second node of the driving transistor and a data line a transistor and a storage capacitor connected between a first node and a second node of the driving transistor;
While the voltage of the reference voltage line or the voltage of the first node of the driving transistor rises,
Further comprising a sensing unit for sensing the voltage of the reference voltage line or the voltage of the first node of the driving transistor twice,
The data driver is
Before the sensing unit first senses the voltage of the reference voltage line or the voltage of the first node of the driving transistor, a first data voltage is output to the data line;
After the sensing unit first senses the voltage of the reference voltage line or the voltage of the first node of the driving transistor, a second data voltage different from the first data voltage is output to the data line. According to claim 1,
and a sampling switch connecting the sensing unit and the reference voltage line twice while the voltage of the reference voltage line or the voltage of the first node of the driving transistor increases. delete According to claim 1,
The second data voltage is a voltage obtained by adding an offset voltage to the first data voltage. 5. The method of claim 4,
The offset voltage is determined by a primary sensing voltage in which the sensing unit first senses the voltage of the reference voltage line or the voltage of the first node of the driving transistor. 6. The method of claim 5,
The offset voltage corresponds to a difference between the primary sensing voltage and a reference voltage. 7. The method of claim 6,
The reference voltage is
The organic light emitting diode display is supplied to the reference voltage line before the voltage of the reference voltage line or the voltage of the first node of the driving transistor rises. According to claim 1,
a voltage difference between the second node and the first node of the driving transistor when the data driver outputs the first data voltage to the data line;
When the data driver outputs the second data voltage to the data line, a voltage difference between the second node and the first node of the driving transistor corresponds to each other. According to claim 1,
The sensing unit calculates a characteristic value of the driving transistor based on a secondary sensing voltage obtained by secondly sensing the voltage of the reference voltage line or the voltage of the first node of the driving transistor, and performing a characteristic value compensation process of the driving transistor The organic light emitting display device further comprising a compensator. 10. The method of claim 9,
The compensation unit,
An organic light emitting display device for calculating mobility of the driving transistor by calculating an amount of voltage increase of the first node of the driving transistor for a predetermined time based on the secondary sensing voltage. A driving method of an organic light emitting display device comprising: an organic light emitting diode display panel including subpixels including an organic light emitting diode and a driving transistor for driving the organic light emitting diode; and a data driver for driving a data line, the method comprising:
an initialization step of applying a reference voltage to a first node of the driving transistor and applying a first data voltage to a second node of the driving transistor; and
While the voltage of the first node of the driving transistor is increased by floating the first node of the driving transistor, the voltage of the first node of the driving transistor or a voltage at another point electrically connected to the first node of the driving transistor is applied. Including a sensing step of sensing twice,
The sensing step is
a primary sensing step of first sensing a voltage of a first node of the driving transistor or a voltage of another point electrically connected to the first node of the driving transistor;
a data offset step of applying a second data voltage different from the first data voltage to a second node of the driving transistor; and
and a secondary sensing step of secondarily sensing a voltage of a first node of the driving transistor or a voltage at another point electrically connected to the first node of the driving transistor. delete 12. The method of claim 11,
The second data voltage is a voltage obtained by adding an offset voltage to the first data voltage. 14. The method of claim 13,
The offset voltage is determined by a primary sensing voltage obtained by first sensing a voltage of a first node of the driving transistor or a voltage at another point electrically connected to the first node of the driving transistor. delete delete delete delete delete delete delete

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