KR102156160B1 - Organic light emitting display device, organic light emitting display panel, and method for driving the organic light emitting display device - Google Patents

Abstract

In the present embodiments, an organic light-emitting display device, an organic light-emitting display panel, and a driving device capable of shortening the sensing time by making the voltage saturation speed of the sensing node faster and allowing the saturation voltage of the sensing node to be sensed at a more appropriate timing. It's about how.

Description

Organic light emitting display device, organic light emitting display panel, and driving method {ORGANIC LIGHT EMITTING DISPLAY DEVICE, ORGANIC LIGHT EMITTING DISPLAY PANEL, AND METHOD FOR DRIVING THE ORGANIC LIGHT EMITTING DISPLAY DEVICE}

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

2. Description of the Related Art Recently, organic light-emitting display devices, which have been in the spotlight as display devices, use organic light-emitting diodes (OLEDs) that emit light by themselves, so that response speed is fast, and luminous efficiency, luminance, and viewing angle are great.

In such an organic light emitting display device, subpixels including organic light emitting diodes are arranged in a matrix form and brightness of pixels selected by a scan signal is controlled.

In addition to the organic light emitting diode, each subpixel of such an organic light emitting display device includes a driving circuit for driving the organic light emitting diode.

The driving circuit of the organic light emitting diode in each of the subpixels includes a transistor and a storage capacitor.

Transistors in the driving circuit have inherent characteristics such as threshold voltage and mobility.

Meanwhile, when the driving time of a transistor in a driving circuit (especially, a driving transistor that supplies current to an organic light emitting diode) increases, degradation may proceed, and the inherent characteristic value of the transistor may change. As a result, variations in intrinsic characteristic values between the respective transistors occur.

Variations in characteristic values between transistors may be a major factor in deteriorating image quality by causing brightness variations between subpixels.

Therefore, a function capable of compensating by sensing the characteristic values of the transistors in each subpixel has been developed.

Meanwhile, in order to sense and compensate for intrinsic characteristic values such as the threshold voltage of a transistor in each subpixel, a specific sensing node in each subpixel is initialized to a certain voltage value and then changed to sense the saturated voltage of a specific sensing node. Based on the sensed voltage by (measurement), it compensates for intrinsic characteristics such as the threshold voltage of the transistor.

At this time, it takes a very long time for the voltage of the sensing node of each subpixel to saturate. Therefore, there is a problem that it takes too much time to complete the sensing operation for all subpixels on the organic light emitting display panel.

It is an object of the present embodiments to provide an organic light emitting display device, an organic light emitting display panel, and a driving method capable of shortening a sensing time.

Another object of the present embodiments is an organic light-emitting display device capable of shortening the sensing time by making the voltage saturation speed of the sensing node faster and allowing the saturation voltage of the sensing node to be sensed at a more appropriate timing. It is to provide a panel and a driving method.

Another object of the present embodiments is to increase the voltage saturation speed of the sensing node by adjusting the data voltage so that the saturation voltage of the sensing node can be sensed at a more appropriate timing, thereby shortening the sensing time. It is to provide a light emitting display device, an organic light emitting display panel, and a driving method.

Another object of the present embodiments is to increase the voltage saturation speed of the sensing node by adjusting the driving voltage voltage, so that the saturation voltage of the sensing node can be sensed at a more timing, thereby shortening the sensing time. An organic light emitting display device, an organic light emitting display panel, and a driving method are provided.

In one embodiment, an organic light emitting display panel on which data lines, gate lines and driving voltage lines are arranged and subpixels are arranged, a data driver supplying data voltages to the data lines, and a scan signal to the gate lines A gate driver that sequentially supplies a gate driver, a timing controller that controls a data driver and a gate driver, a sensor that senses a voltage of a sensing node in each subpixel during a sensing mode period and transmits sensing data, and a compensation process based on the sensing data It provides an organic light emitting display device including a compensator for performing.

In such an organic light emitting display device, the data driver may supply a data voltage that increases by an overshooting voltage value for a predetermined time from a reference data voltage value and then falls back to the reference data voltage value in the sensing mode period.

In another embodiment, data lines arranged in a first direction and supplying data voltages, and subpixels arranged in a second direction crossing the first direction and sequentially arranged in a scan signal with gate lines, in a matrix type It provides an organic light emitting display panel including them.

In such an organic light emitting display panel, in a mode section different from the display mode section, the data voltage supplied through each data line rises from the reference data voltage value by the overshooting voltage value for a certain period of time and then falls back to the reference data voltage value. can do.

In another embodiment, when the sensing mode is enabled, applying a data voltage and a reference voltage to each of a first node and a second node of a driving transistor in a corresponding subpixel, and driving by floating the second node of the driving transistor The steps of increasing the voltage of the second node of the transistor, sensing the voltage of the second node of the driving transistor when the voltage of the second node of the driving transistor rises and then saturates, and the step of sensing the voltage of the second node of the driving transistor Based on the sensing result, it is provided to a driving method of an organic light-emitting display device comprising the step of changing data for a corresponding sub-pixel, and driving the corresponding sub-pixel using the changed data when the display mode is enabled. .

In such a driving method of an organic light emitting display device, the data voltage applied to the first node of the driving transistor may increase from the reference data voltage value by the overshooting voltage value for a predetermined period of time and then decrease again to the reference data voltage value.

In another embodiment, an organic light emitting display panel in which data lines, gate lines, and driving voltage lines are arranged and subpixels are arranged, a data driver supplying data voltages to the data lines, and scanning with gate lines A gate driver that sequentially supplies signals, a timing controller that controls the data driver and the gate driver, a sensor that senses the voltage of the sensing node in each subpixel during the sensing mode period and transmits the sensing data, and compensates based on the sensing data. It provides an organic light emitting display device including a compensator for performing a process.

In such an organic light emitting display device, the driving voltage supplied through the driving voltage lines in the sensing mode period may be higher than the driving voltage supplied through the driving voltage lines in the display mode period.

In yet another embodiment, data lines arranged in a first direction and supplying data voltages, and subs arranged in a second direction crossing the first direction and sequentially arranged in a scan signal in a matrix type It provides an organic light emitting display panel including pixels.

The organic light-emitting display panel may include driving voltage lines that supply a higher driving voltage in a mode period different from the display mode period than in the display driving mode period.

According to the exemplary embodiments described above, an organic light emitting display device, an organic light emitting display panel, and a driving method capable of shortening a sensing time can be provided.

In addition, according to the present embodiments, the voltage saturation speed of the sensing node is made faster, so that the saturation voltage of the sensing node can be sensed at a more appropriate timing, thereby reducing the sensing time. A display panel and a driving method can be provided.

In addition, according to the present embodiments, by adjusting the data voltage, the voltage saturation speed of the sensing node is further accelerated, and the saturation voltage of the sensing node can be sensed at a more timing, thereby reducing the sensing time. A light emitting display device, an organic light emitting display panel, and a driving method can be provided.

In addition, according to the present embodiments, by adjusting the driving voltage voltage, the voltage saturation speed of the sensing node is made faster, and the saturation voltage of the sensing node can be sensed at a more timing, thereby shortening the sensing time. An organic light-emitting display device, an organic light-emitting display panel, and a driving method can be provided.

1 is a configuration diagram of an organic light emitting display device according to the present embodiments.
2 is a simplified equivalent circuit diagram of a subpixel of an organic light emitting display device according to the present exemplary embodiments.
3 illustrates a compensation configuration of an organic light emitting display device according to the present embodiments.
4 illustrates a driving mode of an organic light emitting display panel according to the present embodiments.
5 illustrates a sensing operation step in a sensing mode section of the organic light emitting display device according to the present embodiments.
6 is a diagram illustrating basic signal waveforms of a driving voltage and a data voltage, and a voltage change of a sensing node in a sensing mode section of the OLED display according to the present embodiments.
7 illustrates a signal waveform of an overshooting data voltage vdata in order to shorten a sensing time in a sensing mode section of the organic light emitting display device according to the present embodiments.
FIG. 8 is a diagram illustrating a voltage change of a sensing node when an overshooted data voltage vdata is used in a sensing mode section of the organic light emitting display device according to the present embodiments.
9 illustrates a signal waveform of an increased driving voltage EVDD in order to shorten a sensing time in a sensing mode section of the organic light emitting display device according to the present embodiments.
10 is a diagram illustrating a voltage change of a sensing node when an elevated driving voltage EVDD is used in a sensing mode section of the organic light emitting display device according to the present embodiments.
11 exemplarily shows an equivalent circuit diagram of a subpixel of an organic light emitting display device according to the present embodiments.
12 is a flowchart of a method of driving an organic light emitting display device according to the present embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to elements of each drawing, the same elements may have the same numerals as possible even if they are indicated on 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 subject matter of the present invention, a detailed description thereof may be omitted.

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

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

Referring to FIG. 1, the organic light-emitting display device 100 according to the present embodiments includes an organic light-emitting display panel 110, a data driver 120, a gate driver 130, a timing controller 140, and the like. .

In the organic light emitting display panel 110, a plurality of data lines (DL) are disposed in a first direction, a plurality of gate lines (GL) are disposed in a second direction crossing the first direction, and , A plurality of sub-pixels (SP) are arranged in a matrix type. The data driver 120 drives data lines by supplying data voltages to the data lines. The gate driver 130 sequentially drives the gate lines by sequentially supplying scan signals to the gate lines. The timing controller 140 supplies control signals to the data driver 120 and the gate driver 130 to control the data driver 120 and the gate driver 130.

The timing controller 140 starts scanning according to the timing implemented in each frame, and converts the image data input from the host system 160 according to the data signal format used by the data driver 120. It outputs the image data (Data') and controls the data drive at an appropriate time according to the scan.

The gate driver 130 sequentially drives the gate lines by sequentially supplying scan signals of an on voltage or an off voltage to the gate lines under the control of the timing controller 140.

The gate driver 130 may be located on both sides of the organic light emitting display panel 110 as shown in FIG. 1, depending on the driving method, or may be located only on one side in some cases.

In addition, the gate driver 130 includes a plurality of gate driver integrated circuits (Gate Driver IC, GDIC #1, ..., GDIC #N, GDIC #1', ..., GDIC #N', N: 1 or more. A natural number), and such a plurality of gate driver integrated circuits (GDIC #1, ..., GDIC #N, GDIC #1', ..., GDIC #N') are tape-automated bonding (TAB : Tape AuTrmated Bonding) method or chip-on-glass (COG) method connected to the bonding pad of the display panel 110, or implemented as a GIP (Gate In Panel) type directly to the organic light emitting display panel 110 It may be disposed, and in some cases, may be integrated and disposed on the organic light emitting display panel 110.

Each of a plurality of gate driver integrated circuits (GDIC #1, ..., GDIC #N, GDIC #1', ..., GDIC #N') mentioned above may include a shift register, a level shifter, and the like.

When a specific gate line is opened, the data driver 120 converts the image data Data' received from the timing controller 140 into an analog data voltage Vdata and supplies it to the data lines, thereby driving the data lines. do.

The data driver 120 includes a plurality of source driver integrated circuits (Source Driver IC, also referred to as a data driver IC, SDIC #1, ..., SDIC #M, M: a natural number greater than or equal to 1) Many of these source driver integrated circuits (SDIC #1, ..., SDIC #M) are organic light-emitting displays using a tape-automated bonding (TAB) method or a chip-on-glass (COG) method. It may be connected to a bonding pad of the panel 110, or 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 some cases.

Each of the multiple source driver integrated circuits (SDIC #1, ..., SDIC #M) mentioned above includes a shift register, a latch, a digital analog converter (DAC), an output butter, etc. Accordingly, for subpixel compensation, an analog digital converter (ADC) may be further included that senses an analog voltage value, converts it into a digital value, and generates and outputs the sensing data.

A plurality of source driver integrated circuits (SDIC #1, ..., SDIC #M) may be implemented in a Chip On Film (COF) method. In each of a plurality of source driver integrated circuits (SDIC #1, ..., SDIC #M), one end is bonded to at least one source printed circuit board, and the other end is an organic light emitting display panel ( 110).

Meanwhile, the host system 160 mentioned above includes a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), an input data enable (DE: Data Enable) signal, and a clock together with the digital video data (Data) of the input image. Various timing signals including a signal CLK and the like are transmitted to the timing controller 140.

The timing controller 140 converts the data input from the host system 160 according to the data signal format used by the data driver 120 to output the converted image data Data'. In order to control the driving unit 120 and the gate driving unit 130, timing signals such as a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), an input DE signal, and a clock signal are received, and various control signals are generated to generate data. Output to the driver 120 and the gate driver 130.

For example, in order to control the gate driver 130, the timing controller 140 includes a gate start pulse (GSP), a gate shift clock (GSC), and a gate output enable signal (GOE). : Gate Control Signals (GCSs) including Gate Output Enable) are output. The gate start pulse (GSP) starts the operation of gate driver integrated circuits (GDIC #1, ..., GDIC #N, GDIC #1', ..., GDIC #N') constituting the gate driver 130 Control the timing. The gate shift clock (GSC) is a clock signal commonly input to gate driver integrated circuits (GDIC #1, ..., GDIC #N, GDIC #1', ..., GDIC #N'), and is a scan signal Controls the shift timing of (gate pulse). The gate output enable signal GOE designates timing information of gate driver integrated circuits GDIC #1, ..., GDIC #N, GDIC #1', ..., GDIC #N'.

In order to control the data driver 120, the timing controller 140 includes a source start pulse (SSP), a source sampling clock (SSC), and a source output enable signal (SOE: Souce Output Enable). ) Outputs data control signals (DCSs) including. The source start pulse SSP controls the data sampling start timing of the source driver integrated circuits (SDIC #1, ..., SDIC #M) constituting the data driver 120. The source sampling clock (SSC) is a clock signal that controls the sampling timing of data in each of the source driver integrated circuits (SDIC #1, ..., SDIC #M). The source output enable signal SOE controls the output timing of the data driver 120. In some cases, in order to control the polarity of the data voltage of the data driver 120, the polarity control signal POL may be further included in the data control signals DCSs. If data' input to the data driver 120 is transmitted according to the mini Low Voltage Differential Signaling (LVDS) interface standard, the source start pulse SSP and the source sampling clock SSC may be omitted.

Referring to FIG. 1, the organic light emitting display device 100 supplies various voltages or currents to the organic light emitting display panel 110, the data driver 120, the gate driver 130, or controls various voltages or currents to be supplied. It may further include a power controller 150.

The power controller 150 is also referred to as a power management integrated circuit (PMIC).

2 is a simplified equivalent circuit diagram of a subpixel of the organic light emitting display device 100 according to the present exemplary embodiments.

Referring to FIG. 2, each subpixel of the organic light emitting display device 100 is basically composed of an organic light emitting diode (OLED) and a driving circuit that drives the organic light emitting diode (OLED).

Referring to FIG. 2, the driving circuit basically includes a driving transistor (DRT) that drives the organic light-emitting diode (OLED) by supplying current to the organic light-emitting diode (OLED).

The first node N1 of the driving transistor DRT is a gate node, and a voltage V1 is applied thereto. The second node N2 of the driving transistor DRT is a source node or a drain node, and a voltage V2 is applied thereto. The third node N3 of the driving transistor DRT is a drain node or a source furnace, and a driving voltage (EVDD) is applied thereto. Here, the voltage V1 may be a data voltage Vdata corresponding to a corresponding subpixel. The voltage V2 is a voltage having a certain potential difference from the voltage V1, and may be, for example, a reference voltage (Vref).

Referring to FIG. 2, the driving circuit may include a storage capacitor Cstg (STrrage CapaciTrr) connected between nodes N1 and N2 of the driving transistor DRT. This storage capacitor Cstg maintains a constant voltage for one frame.

FIG. 2 is a simplified and equivalent diagram of a circuit configuration of each subpixel. In practice, a driving circuit for driving an organic light emitting diode (OELD) in each subpixel includes a driving transistor (DRT) and a storage capacitor (Cstg). In addition, one or more transistors may be further included, and in some cases, one or more capacitors may be further included.

Meanwhile, a transistor in each subpixel, in particular, a driving transistor DRT has unique characteristic values such as a threshold voltage (Vth) and a mobility (μ).

When the driving time of the transistor (especially, the driving transistor DRT) increases, degradation proceeds, and the characteristic value of the transistor may change. As a result, variations in intrinsic characteristic values between the respective transistors occur.

Variations in characteristic values between transistors may be a major factor in deteriorating image quality by causing brightness variations between subpixels.

Accordingly, the organic light emitting display device 100 according to the present embodiments includes a compensation component that provides a compensation function for compensating for a luminance deviation between subpixels.

3 shows a compensation configuration of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 3, the organic light emitting display device 100 according to the present embodiments includes a sensor 310 and a compensator 320.

The sensor 310 senses the voltage of a sensing node SN in each subpixel SP, and transmits the sensing data Dsen to the compensator 320 based on the sensed voltage Vsen.

The sensor 310 may be, for example, an analog digital converter (ADC).

The analog-to-digital converter ADC may be electrically connected to a sensing node SN in each subpixel through a sensing line SL.

The analog-to-digital converter (ADC) converts the sensed voltage (Vsen) of the sensing node (SN) into a digital value through a sensing line (SL) electrically connected to the sensing node (SN) in each subpixel, and converts it. The sensing data Dsen is generated based on the digital values.

There may be a plurality of sensors 310 corresponding to the analog-to-digital converter (ADC), and one sensor 310, that is, one analog-to-digital converter (ADC) may be included in one source driver integrated circuit.

The compensator 320 performs a compensation process based on the received sensing data Dsen.

The compensation process is a process of determining a data compensation amount (ΔData) for changing data (Data) for each of a plurality of subpixels based on the received sensing data, and storing the data compensation amount in a memory (not shown). Can be

In addition, the compensation process may include a process of changing the data output from the hose system 160 based on the data compensation amount ΔData. This data change process may be changed into change data (Data'=Data+ΔData) by adding a data compensation amount (ΔData) to the data (Data) output from the hose system 160.

The compensator 320 may be included in the timing controller 140.

4 illustrates a driving mode of the organic light emitting display panel 110 according to the present embodiments.

Referring to FIG. 4, the organic light-emitting display panel 110 according to the present embodiments may operate in a driving mode such as a display mode and a sensing mode.

The display mode is a driving mode for the organic light emitting display panel 110 to display an image.

The sensing mode is a driving mode related to the above-described compensation function, and is a driving mode for sensing the organic light emitting display panel 110. That is, the sensing mode is a driving mode for sensing a characteristic value of a transistor (especially, a driving transistor) in each subpixel on the organic light emitting display panel 110. In this sensing mode, the voltage of the sensing node in each subpixel Is sensed.

Such a sensing mode, for example, may be performed in real time while the organic light emitting display panel 110 is operating in the display mode, or may be performed when a power off signal is generated, and in some cases, a power on signal It may be made when (Power On Signal) occurs.

When the sensing mode is performed in real time, the sensing mode may be performed at each blank time of the vertical synchronization signal Vsync. In this case, the sensing mode performed at each blank time is a sensing mode for sensing and compensating for mobility that takes a relatively small sensing time among the inherent characteristic values of transistors (especially, driving transistors) in each subpixel on the organic light emitting display panel 110 Can be

When the sensing mode is performed when the power-off signal is generated, the sensing mode performs sensing of a threshold voltage, which takes a relatively long sensing time, among characteristic values of transistors (especially, driving transistors) in each subpixel on the organic light emitting display panel 110. It may be a sensing mode for.

A basic method and principle of sensing the threshold voltage of the driving transistor DRT in each subpixel on the organic light emitting display panel 110 will be described with reference to FIGS. 5 and 6.

5 illustrates a sensing operation step in a sensing mode section of the organic light emitting display device 100 according to the present embodiments. 6 is a diagram illustrating a basic signal waveform of a driving voltage and a data voltage and a voltage change of a sensing node in a sensing mode section of the organic light emitting display device 100 according to the present embodiments.

5 and 6, the sensing operation step in the sensing mode period of the organic light emitting display device 100 according to the present embodiments includes an initialization step (STEP 1), a sensing node floating step (STEP 2), and a sensing node. It consists of a sensing step (STEP 3).

5 and 6, after the sensing mode is enabled in the initialization step (STEP 1), the first node N1 and the second node N2 of the driving transistor DRT in the corresponding subpixel are ) Is applied to each of the data voltage Vdata and the reference voltage Vref. Here, it is assumed that the first node N1 of the driving transistor DRT is a gate node of the driving transistor DRT, and the second node N2 of the driving transistor DRT is a source node of the driving transistor DRT. . In addition, it is assumed that the source node of the driving transistor DRT is a sensing node in a corresponding subpixel.

5 and 6, in the sensing node floating step (STEP 2), the second node N2 of the driving transistor DRT, that is, the source node of the driving transistor DRT, is floating at a time point Tr. do.

At this time, the first node N1 of the driving transistor DRT is in a state in which the data voltage Vdata corresponding to the initialization voltage is applied as it is.

As the second node N2 of the driving transistor DRT, that is, the source node of the driving transistor DRT, is floating, the voltage of the second node N2 of the driving transistor DRT is boosted. do.

The voltage increase of the source node of the driving transistor DRT is made toward the data voltage Vdata corresponding to the voltage of the first node N1 of the driving transistor DRT, and the first node of the driving transistor DRT It is performed until a difference is made by the data voltage Vdata corresponding to the voltage of (N1) and the threshold voltage Vth.

In this way, the voltage of the second node N2 of the driving transistor DRT, that is, the source node of the driving transistor DRT, is boosted toward the voltage of the first node N1 of the driving transistor DRT. This is called "Source Following".

5 and 6, in the sensing node sensing step (STEP 3), when the voltage of the second node N2 of the driving transistor DRT increases and then saturates at a time point Tsat, the driving transistor DRT The saturated voltage of the second node N2 of is sensed.

Here, the saturated voltage of the second node N2 of the driving transistor DRT, that is, the source node of the driving transistor DRT, is a data voltage corresponding to the voltage of the first node N1 of the driving transistor DRT. It becomes a voltage (Vdata-Vth=Vd-Vth) obtained by subtracting the threshold voltage Vth of the driving transistor DRT from (Vdata). However, in FIG. 6, a case in which the threshold voltage Vth of the driving transistor DRT is a positive value is illustrated, and the threshold voltage Vth of the driving transistor DRT may be a negative value.

5 and 6, in the sensing mode period, the data voltage Vdata has a constant voltage Vd, and the driving voltage EVDD also has a constant voltage Ve.

5 and 6, in order to accurately sense the threshold voltage Vth of the driving transistor DRT in the sensing mode period, the sensing node SN in the corresponding subpixel, that is, the driving transistor DRT. After the second node N2 is saturated, the voltage of the second node N2 of the driving transistor DRT should be sampled by an analog-to-digital converter ADC corresponding to the sensor 310 and sensed (measured). .

The length of time it takes to sense the threshold voltage Vth of the driving transistor DRT is the sensing node SN in the subpixel, that is, the second node N2 of the driving transistor DRT is floated. It depends on the length of time TL from the time point Tr to the time point Tsat to be saturated.

Since the sensing node SN in the subpixel, that is, the second node N2 of the driving transistor DRT, takes a considerable amount of time (TL=Tsat-Tr) to float and saturate, the driving transistor DRT It takes a lot of time to sense the threshold voltage Vth.

Below, in order to shorten the time required for sensing the threshold voltage Vth of the driving transistor DRT, that is, the sensing time, the second node N2 of the driving transistor DRT, that is, the driving transistor DRT. Several methods of saturating the source node of the saturation faster are described.

First, a method of saturating the sensing node more quickly by adjusting the data voltage Vdata will be described with reference to FIGS. 7 and 8.

7 illustrates a signal waveform of an overshooting data voltage vdata in order to shorten a sensing time in a sensing mode section of the organic light emitting display device 100 according to the present embodiments. 8 is a diagram illustrating a voltage change of a sensing node when an overshooted data voltage vdata is used in a sensing mode section of the organic light emitting display device 100 according to the present embodiments.

7 and 8, in order to shorten the sensing time, that is, to make the voltage saturation of the second node N2 of the driving transistor DRT, that is, the source node of the driving transistor DRT, faster, As shown in FIG. 6, the data driver 120 does not supply the data voltage Vdata of a constant voltage value Vd to the first node N1 of the driving transistor DRT, but overshooting data The voltage Vdata may be supplied to the first node N1 of the driving transistor DRT.

7 and 8, the data driver 120 increases the overshooting voltage value (ΔVd) for a predetermined time (ΔT) from the reference data voltage value (Vd) in the sensing mode section A data voltage Vdata that falls back to the voltage value Vd may be supplied.

That is, in a mode period different from the display mode period, that is, in the sensing mode period, the data voltage Vdata supplied through each data line DL exceeds the reference data voltage value Vd for a certain period of time (△T). It rises by the shooting voltage value (ΔVd) and then falls back to the reference data voltage value (Vd).

7 and 8, when the data voltage Vdata is overshooting from the reference data voltage value Vd, the second node N2 of the driving transistor DRT is floating. It may be the same as the time point Tr.

7 and 8, the overshooting voltage value ΔVd at which the data voltage Vdata is overshooting from the reference data voltage value Vd is the driving transistor DRT. The voltage saturation timing of the second node N2 of may be a preset value so that the voltage saturation time of is sufficiently rapid.

7 and 8, when the data voltage Vdata is temporarily overshooting from the reference data voltage value Vd, the voltage of the first node N1 of the driving transistor DRT temporarily increases. Thus, the potential difference between both ends of the storage capacitor Cstg connected between the first node N1 and the second node N2 of the driving transistor DRT temporarily increases, so that the charging speed of the storage capacitor Cstg temporarily increases. .

Accordingly, as illustrated in FIG. 8, when overshooting the data voltage Vdata, a time point Tsat' at which the voltage V2 of the second node N2 of the driving transistor DRT saturates is, When overshooting the data voltage Vdata is not performed, the voltage V2 of the second node N2 of the driving transistor DRT becomes faster than the saturation time Tsat.

As described above, by temporarily overshooting the data voltage Vdat in the sensing mode period, the voltage saturation speed of the sensing node can be accelerated.

Meanwhile, referring to FIGS. 7 and 8, in the sensing mode period, the data voltage Vdata increases from the reference data voltage value Vd by the overshooting voltage value ΔVd at the time point Tr, and then the reference data voltage value ( The time point Tf that falls back to Vd may be earlier than the voltage saturation time point Tsat' of the second node N2 of the driving transistor DRT.

For this reason, in a mode section different from the display mode section, that is, in the sensing mode section, the data voltage Vdata rises from the reference data voltage value Vd by the overshooting voltage value (ΔVd) at the time Tr, and then the reference data voltage A time point Tf that falls back to the value Vd may be earlier than a time point at which the sensor 310 senses the voltage of the sensing node (a time point Tsat' or a time point thereafter).

In this regard, referring to FIGS. 7 and 8, the voltage of the second node N2 of the driving transistor DRT does not finally rise toward the overshooted voltage value (Vd+ΔVd), but the reference It rises toward the data voltage value (Vd). That is, finally, the voltage rise width of the voltage of the second node N2 of the driving transistor DRT is not "Vd+ΔVd-Vth-Vref" but "Vd-Vth-Vref".

In other words, since the data voltage (Vdata) temporarily overshoots from the reference data voltage value (Vd) and then returns to the reference data voltage value (Vd), the charging rate of the storage capacitor (Cstg) is temporarily increased. By speeding it up, the voltage saturation speed of the second node N2 of the driving transistor DRT can be increased while maintaining the voltage rise width for voltage saturation of the second node N2 of the driving transistor DRT as it is.

That is, finally, in both the data voltage adjustment (FIG. 6) and the data voltage adjustment, the voltage of the second node N2 of the driving transistor DRT is "Vd-Vth" from the reference voltage Vref. The same rises until ".

By overshooting the data voltage of the above-described method, the saturation speed for the voltage of the second node N2 of the driving transistor DRT is accelerated to shorten the sensing time, while the time when the overshooted data voltage falls By making (Tf) faster than the point when the sensing node voltage is saturated (Tsat'), the saturation voltage for the voltage of the second node N2 of the driving transistor DRT is the reference data voltage value (Vd) of the data voltage (Vdata). The voltage (Vd-Vth) obtained by subtracting the threshold voltage (Vth) can be maintained equally.

Next, a method of saturating the sensing node more quickly by adjusting the driving voltage EVDD will be described with reference to FIGS. 9 and 10.

9 illustrates a signal waveform of an increased driving voltage EVDD in order to shorten a sensing time in a sensing mode section of the organic light emitting display device 100 according to the present embodiments. 10 is a diagram illustrating a voltage change of a sensing node when an elevated driving voltage EVDD is used in a sensing mode section of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 9, the organic light emitting display device 100 according to the present embodiments may adjust the driving voltage EVDD in order to shorten the sensing time by making the saturation timing of the voltage of the sensing node faster.

Referring to FIG. 9, the driving voltage EVDD supplied through the driving voltage lines DVL in a mode period different from the display mode period, that is, in the sensing mode period, is supplied through the driving voltage lines DVL in the display mode period. The voltage value (Ve+ΔVe) may be higher than the reference driving voltage value Ve of the driving voltage by a predetermined voltage value (ΔVe). Here, the reference driving voltage value Ve may be a voltage value of the driving voltage EVDD used in the display mode period.

That is, in a mode period different from the display mode period, that is, in the sensing mode period, the driving voltage lines DRLs may supply a higher driving voltage EVDD than in the display driving mode period.

Such driving voltage control may be performed by the timing controller 140 and the power controller 150.

When the first node N1, the second node N2, and the third node N3 of the driving transistor DRT are gate nodes, source nodes, and drain nodes, referring to Equation 1 below, the driving transistor DRT When the driving voltage EVDD applied to the third node N3 of) is increased, the voltage difference between the drain node and the source node of the driving transistor DRT, Vds, increases.

In Equation 1, id is the current flowing to the drain node N3 of the driving transistor DRT, W is the width of the channel of the driving transistor DRT, and L is the driving transistor DRT. Is the length of a channel of, and kn' is a transconductance parameter, and is μCox. μ is the electron mobility of the driving transistor (DRT), and Cox is the oxide capacitance (Oxide Capacitance). In addition, Vgs is the voltage difference between the gate node N1 and the source node N2 of the driving transistor DRT, and Vds is the voltage difference between the drain node N3 and the source node N2 of the driving transistor DRT. In addition, λ is a parameter representing a relationship in which id is dependent on Vds, and may be a positive (+) constant value, for example, 0.005 to 0.03 [1/V].

In Equation 1, in the (1+λVds) item, it can be seen that as Vds increases, id increases.

In this way, the current id flowing to the drain node N3 of the driving transistor DRT increases, so that the storage capacitor Cstg is charged faster. That is, the voltage of the source node N2 of the driving transistor DRT saturates faster.

In other words, when the driving voltage EVDD is increased by a certain voltage value ΔVe from the reference driving voltage value Ve in the sensing mode period (FIG. 10), the second node N2 of the driving transistor DRT, for example : The saturation point (Tsat") of the voltage V2 of the source node) is the second of the driving transistor DRT when the driving voltage EVDD is a constant reference driving voltage value Ve in the sensing mode section (Fig. 6). It is faster than the saturation point Tsat of the voltage V2 of the two nodes (N2, for example, the source node).

When the driving voltage adjustment method, that is, when the driving voltage EVDD supplied through the driving voltage lines DVL is increased in the sensing mode period, the second node N2 of the driving transistor DRT, that is, the voltage of the sensing node The saturation speed of is increased, so that the saturation voltage of the sensing node can be sensed at an earlier time (Tsat" or later) for sensing the threshold voltage of the driving transistor DRT.

Two methods (data voltage adjustment method, driving voltage adjustment method) for shortening the sensing time described above are used to sense the unique characteristic values of transistors (especially driving transistors) in each subpixel disposed on the organic light emitting display panel 110. When, it can be used.

Hereinafter, a detailed structure of the subpixel of the organic light emitting display device 100 to which the above-described two methods (data voltage adjustment method, driving voltage adjustment method) can be applied to shorten the sensing time will be exemplarily described with reference to FIG. do.

11 exemplarily shows an equivalent circuit diagram of subpixels of the organic light emitting display device 100 according to the present embodiments.

In the subpixel SP illustrated in FIG. 11, a driving circuit for driving an organic light emitting diode (OLED) includes three transistors (DRT, T1, T2) and one capacitor (Cstg). (Capacitor) structure.

Referring to FIG. 11, the driving transistor DRT is electrically connected to a first node N1 to which a data voltage Vdata is applied, and a first electrode (eg, an anode electrode or a cathode electrode) of an organic light emitting diode OLED. It has a second node N2 connected in a manner and a third node N3 electrically connected to the driving voltage line DVL to which the driving voltage EVDD is applied.

Referring to FIG. 11, a first transistor T1 is electrically connected between a data line DL supplying a data voltage and a first node N1 of a driving transistor DRT.

The gate node of the first transistor T1 receives a scan signal through the first gate line GLj. The drain node or source node of the first transistor T1 receives the data voltage Vdata from the data line DLi. The source node or drain node of the first transistor T1 is electrically connected to the first node N1 of the driving transistor DRT.

When the first transistor T1 is turned on by the scan signal, the data voltage Vdata supplied to the drain node or the source node of the first transistor T1 is applied to the source node or the drain node of the first transistor T1. It is applied to the first node N1 of the driving transistor DRT that is electrically connected.

Referring to FIG. 11, the second transistor T2 is electrically connected between the reference voltage line RVL supplying the reference voltage Vref and the second node N2 of the driving transistor DRT.

The gate node of the second transistor T2 receives a sense signal, which is a type of scan signal, through the second gate line GLj'. The drain node or source node of the second transistor T2 receives the reference voltage Vref from the reference voltage line RVL. The source node or drain node of the second transistor T2 is electrically connected to the second node N2 of the driving transistor DRT.

Referring to FIG. 11, the storage capacitor Cstg is electrically connected between the first node N1 and the second node N2 of the driving transistor DRT.

The subpixel structure of 3T1C shown in FIG. 11 is a structure capable of sensing and compensating for a subpixel.

Referring to FIG. 11, the sensor 310 senses a voltage of a second node N2 of a driving transistor DRT corresponding to a sensing node through a reference voltage line RVL, and converts the sensed voltage to a digital value. And transmits the sensing data including the converted digital value to the compensator 320.

Accordingly, the compensator 320 performs a compensation process using the received sensing data to determine the data compensation amount ΔData. Accordingly, the data change unit 1100 changes the data input from the outside based on the data compensation amount ΔData, and changes the changed data Data' to the corresponding source driver integrated circuit (SDIC #K, K=1, ..., M).

Accordingly, the source driver integrated circuit (SDIC #K) converts the change data (Data') into a data voltage (Vdata) and supplies it to the data line (DLi).

In the example of FIG. 11, the sensor 310 is an analog-to-digital converter (ADC) included in the corresponding source driver integrated circuit (SDIC #K, K=1, ..., M), and the compensator 320 is a timing controller ( 140).

As described above, by adjusting the data voltage and/or the driving voltage, the voltage saturation speed of the sensing node SN, that is, the second node N2 of the driving transistor DRT, is accelerated, thereby shortening the sensing time. A 3T1C subpixel structure can be provided.

Referring to FIG. 11, a switch SW for connecting the reference voltage line RVL to the reference voltage supply node or sensor 310 may be further included. Here, the reference voltage supply node is a node to which the reference voltage is supplied from the power controller 150 to the source driver integrated circuit (SDIC #K), and is a node in which the switch SW is turned on.

The switch SW is turned on in the initializing step (STEP 1 step) of the sensing mode period and applies the reference voltage Vref to the second node N2 of the driving transistor DRT.

However, the floating of the second node N2 of the driving transistor DRT may be performed by turning off the second transistor T2.

Alternatively, the floating of the second node N2 of the driving transistor DRT does not turn the switching operation of the switch SW into the second stage of ON-OFF, but the reference voltage supply node and the reference voltage line RVL. ), a switching step for connecting the sensor 310 and the reference voltage line RVL, and a switching step for not connecting both the reference voltage supply node and the sensor 310 to the reference voltage line RVL. By implementing the switching operation, the second node N2 of the driving transistor DRT may be floated.

In addition, the switch SW is turned off in the sensing step (STEP 3) in the sensing mode section, so that the sensor 310 can sense the voltage of the second node N2 of the driving transistor DRT. .

The timing of the switching operation of the switch SW as described above may be controlled by a control signal output from the timing controller 140.

Through the above-described switch SW, voltage application and voltage sensing of the driving transistor DRT to the second node N2 of the driving transistor DRT can be performed at a desired timing in accordance with the sensing operation.

In FIG. 11, a sensing node (SN) in each subpixel SP is a second node N2 of the driving transistor DRT.

In FIG. 11, in a mode section different from the display mode section, the data voltage Vdata increases from the reference data voltage value Vd by the overshooting voltage value ΔVd and then falls back to the reference data voltage value Vd. A time point Tf is earlier than a time point Tsat' when the voltage V2 of the second node N2 of the driving transistor DRT rises and then saturates at the time Tr.

Through the above-described overshooting method for the data voltage, the saturation speed for the voltage of the second node N2 of the driving transistor DRT is further accelerated to shorten the sensing time, while the time when the overshooted data voltage falls By making (Tf) faster than the point when the sensing node voltage is saturated (Tsat'), the saturation voltage for the voltage of the second node N2 of the driving transistor DRT is the reference data voltage value (Vd) of the data voltage (Vdata). The voltage (Vd-Vth) obtained by subtracting the threshold voltage (Vth) can be maintained equally.

Hereinafter, a method of shortening the sensing time (data adjustment method, driving voltage adjustment method) described above will be briefly described.

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

Referring to FIG. 12, in the driving method of the organic light emitting display device 100 according to the present embodiments, the step of enabling a sensing mode (S1210) and a first node of a driving transistor DRT in a corresponding subpixel ( Applying the data voltage Vdata and the reference voltage Vref to each of the N1 and the second node M2 (S1220), and by floating the second node N2 of the driving transistor DRT, the driving transistor ( Step S1230 of raising the voltage of the second node N2 of the DRT, and when the voltage of the second node N2 of the driving transistor DRT increases and then saturates, the second node of the driving transistor DRT ( The step of sensing the voltage of N2) (S1240) and the step of changing data for the corresponding subpixel (S1250) based on the result of sensing the voltage of the second node N2 of the driving transistor DRT (S1250), and a display When the mode is enabled, a step of driving a corresponding subpixel by using the changed data (S1260), and the like.

The data voltage Vdata applied to the first node N1 of the driving transistor DRT rises from the reference data voltage value Vd by the overshooting voltage value ΔVd for a certain period of time and then increases the reference data voltage value ( Vd) can be lowered again (see Figs. 8 and 9)

The overshooting of the data voltage Vdata may be performed in step S1220.

That is, the overshooting timing Tr of the data voltage Vdata may be a floating timing Tr of the second node N2 of the driving transistor DRT in step S1220. The point at which the data voltage (Vdata) rises by the overshooting voltage value (△Vd) and then falls back to the reference data voltage value (Vd) (Tf), that is, the time point at which the overshooted data voltage (Vdata) falls (Tf) Is before the voltage saturation time Tsat' of the second node N2 of the driving transistor DRT in step S1220.

As described above, by temporarily overshooting the data voltage Vdat in the sensing mode period, the voltage saturation speed of the sensing node can be accelerated.

On the other hand, after the sensing mode is enabled, that is, after step S1210, the driving voltage EVDD applied to the third node N3 of the driving transistor DRT is, in the display mode period, the second voltage of the driving transistor DRT. The voltage value may be higher than the driving voltage EVDD applied to the third node N3 (see FIGS. 9 and 10 ).

As shown in FIG. 10, the rising point of the driving voltage EVDD may be after step S1210 and before the step S1220 of initializing the first node N1 and the second node N2 of the driving transistor DRT. have.

In addition, as shown in FIG. 10, the falling time point of the driving voltage EVDD may be after step S1240 of sensing the voltage of the second node N2 of the driving transistor DRT.

As described above, by increasing the driving voltage EVDD supplied through the driving voltage lines DVL in the sensing mode period, the second node N2 of the driving transistor DRT, that is, the voltage of the sensing node is saturated. By increasing the speed, the saturation voltage of the sensing node can be made into a state in which the saturation voltage of the sensing node can be sensed at a faster time (Tsat" or later).

According to the exemplary embodiments described above, the organic light emitting display device 100, the organic light emitting display panel 110, and a driving method capable of shortening the sensing time can be provided.

In addition, according to the present embodiments, the organic light emitting display device 100 capable of shortening the sensing time by making the voltage saturation speed of the sensing node faster and allowing the saturation voltage of the sensing node to be sensed at a more appropriate timing. , An organic light emitting display panel 110 and a driving method may be provided.

In addition, according to the present embodiments, by adjusting the data voltage, the voltage saturation speed of the sensing node is further accelerated, and the saturation voltage of the sensing node can be sensed at a more timing, thereby reducing the sensing time. A light emitting display device 100, an organic light emitting display panel 110, and a driving method may be provided.

In addition, according to the present embodiments, by adjusting the driving voltage voltage, the voltage saturation speed of the sensing node is made faster, and the saturation voltage of the sensing node can be sensed at a more timing, thereby shortening the sensing time. An organic light emitting display device 100, an organic light emitting display panel 110, and a driving method may be provided.

The description above and the accompanying drawings are merely illustrative of the technical idea of the present invention, and those of ordinary skill in the technical field to which the present invention pertains, combinations of configurations without departing from the essential characteristics of the present invention Various modifications and variations, such as separation, substitution, and alteration, will be possible. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted 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: timing controller

Claims (14)

An organic light emitting display panel on which data lines, gate lines and driving voltage lines are disposed, and subpixels are disposed;
A data driver supplying data voltages to the data lines;
A gate driver sequentially supplying scan signals to the gate lines;
A timing controller that controls the data driver and the gate driver;
A sensor that senses a voltage of a sensing node in each subpixel during a sensing mode period and transmits sensing data; And
Including a compensator for performing a compensation process based on the sensing data,
And the data driver supplies a data voltage that increases by an overshooting voltage value for a predetermined time from a reference data voltage value and then falls back to the reference data voltage value in the sensing mode period. The method of claim 1,
In the sensing mode period, a time point at which the data voltage rises by the overshooting voltage value and then falls back to the reference data voltage value is earlier than a time point at which the sensor senses the voltage of the sensing node. Luminous display device. The method of claim 1,
A driving voltage supplied through the driving voltage lines in the sensing mode period is higher than a driving voltage supplied through the driving voltage lines in a display mode period. The method of claim 1,
Each of the subpixels,
An organic light emitting diode,
A driving transistor having a first node to which the data voltage is applied, a second node electrically connected to the first electrode of the organic light emitting diode, and a third node electrically connected to the driving voltage line,
A first transistor electrically connected between the data line supplying the data voltage and a first node of the driving transistor,
A second transistor electrically connected between a reference voltage line supplying a reference voltage and a second node of the driving transistor,
An organic light emitting display device comprising a capacitor electrically connected between a first node and a second node of the driving transistor. The method of claim 4,
An organic light-emitting display device further comprising a switch connecting the reference voltage line to a reference voltage supply node or the sensor. The method of claim 4,
The sensing node in each subpixel is a second node of the driving transistor. Data lines disposed in a first direction and supplying data voltages;
Gate lines disposed in a second direction crossing the first direction and sequentially receiving a scan signal; And
Including subpixels arranged in a matrix type,
In a mode period different from the display mode period, the data voltage supplied through each of the data lines is,
An organic light-emitting display panel, comprising: an overshooting voltage value rising from a reference data voltage value for a predetermined period of time and then falling back to the reference data voltage value. The method of claim 7,
An organic light-emitting display panel including driving voltage lines supplying a higher driving voltage than in the display driving mode period in a mode period different from the display mode period. The method of claim 7,
Each of the subpixels,
An organic light emitting diode,
A driving transistor having a first node to which the data voltage is applied, a second node connected to the first electrode of the organic light emitting diode, and a third node electrically connected to a driving voltage line,
A first transistor electrically connected between the data line supplying the data voltage and a first node of the driving transistor,
A second transistor electrically connected between a reference voltage line supplying a reference voltage and a second node of the driving transistor,
An organic light-emitting display panel comprising a capacitor electrically connected between a first node and a second node of the driving transistor. The method of claim 9,
In a mode period different from the display mode period, a point in time when the data voltage rises by the overshooting voltage value and then falls back to the reference data voltage value,
The organic light-emitting display panel according to claim 1, wherein the voltage of the second node of the driving transistor increases and then saturates. When the sensing mode is enabled, applying a data voltage and a reference voltage to each of the first node and the second node of the driving transistor in the corresponding subpixel;
Floating a second node of the driving transistor to increase a voltage of the second node of the driving transistor; And
Sensing the voltage of the second node of the driving transistor when the voltage of the second node of the driving transistor rises and then saturates;
Changing data for the corresponding subpixel based on a result of sensing the voltage of the second node of the driving transistor; And
When the display mode is enabled, including the step of driving the corresponding sub-pixel using the changed data,
The data voltage applied to the first node of the driving transistor is
A method of driving an organic light-emitting display device, comprising: rising from a reference data voltage value by an overshooting voltage value for a predetermined time and then falling back to the reference data voltage value. The method of claim 11,
In the sensing mode period, the driving voltage applied to the third node of the driving transistor is higher than the driving voltage applied to the third node of the driving transistor in the display mode period. Way. An organic light emitting display panel on which data lines, gate lines and driving voltage lines are disposed, and subpixels are disposed;
A data driver supplying data voltages to the data lines;
A gate driver sequentially supplying scan signals to the gate lines;
A timing controller that controls the data driver and the gate driver;
A sensor that senses a voltage of a sensing node in each subpixel during a sensing mode period and transmits sensing data; And
Including a compensator for performing a compensation process based on the sensing data,
A driving voltage supplied through the driving voltage lines in the sensing mode period is higher than a driving voltage supplied through the driving voltage lines in a display mode period. Data lines disposed in a first direction and supplying data voltages;
Gate lines disposed in a second direction crossing the first direction and sequentially receiving a scan signal;
Subpixels arranged in a matrix type; And
An organic light emitting display panel including driving voltage lines supplying a higher driving voltage than in the display driving mode period in a mode period different from the display mode period.

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