KR102613329B1 - Organic light emitting display device and method for driving the organic light emitting display device - Google Patents

Abstract

These embodiments relate to an organic light emitting display device and a method of driving the organic light emitting display device, in which the characteristic value of a driving transistor in a subpixel of the organic light emitting display device is sensed two or more times in separate sensing sections and driven by the average value of the sensed values. By generating sensing data for the characteristic values of the transistor or extracting some sensing values from each sensing section and combining the extracted sensing values to generate sensing data, the error in the sensing value due to the power ripple applied when sensing the characteristic value of the driving transistor is generated. This minimizes the impact on sensing data and prevents screen defects due to compensation for errors in sensing values.

Description

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

These embodiments relate to an organic light emitting display device and a method of driving the organic light emitting display device.

Organic light emitting displays, which have recently been in the spotlight as display devices, have the advantages of fast response speed, high contrast ratio, luminous efficiency, brightness, and viewing angle by using organic light emitting diodes (OLEDs: Organic Light Emitting Diodes) that emit light on their own.

This organic light emitting display device includes an organic light emitting display panel including a plurality of gate lines and a plurality of data lines and a plurality of subpixels arranged in an area where the gate lines and data lines intersect, and driving the plurality of gate lines. It may include a gate driver that drives a plurality of data lines, a data driver that drives a plurality of data lines, and a timing controller that controls the operation of the gate driver and the data driver. It may include a driving transistor that drives a diode (OLED).

In these organic light emitting display devices, circuit elements such as organic light emitting diodes (OLEDs) or driving transistors included in each subpixel each have unique characteristics (e.g. threshold voltage, mobility, etc.), and the driving time of the organic light emitting display device Depending on this, degradation may progress and its unique characteristics may change.

This change in the characteristics of the circuit elements causes luminance deviation between each subpixel including the circuit elements, causing a problem in that the overall luminance uniformity of the organic light emitting display panel deteriorates.

In order to solve this problem, a technology is being applied that senses the characteristic values of the circuit elements included in each subpixel and compensates for the characteristic values of the circuit elements based on the sensed values.

Sensing the characteristics of circuit elements is sequentially performed for each gate line by the operation of the gate line, and various power sources for sensing the characteristics of the circuit elements are applied at the same time.

At this time, ripple may occur in the power applied for sensing the characteristic value of the circuit element. If ripple occurs in the power supply, an error term (error term) may occur in the sensing value of the characteristic value of the circuit element due to the ripple, and the sensed value The error affects the compensation value.

Therefore, when sensing the characteristics of a circuit element, incorrect characteristic value sensing and compensation are performed due to the ripple of the applied power, and there is a problem in that incorrect compensation causes screen defects such as horizontal lines on the screen.

The purpose of the present embodiments is to provide an organic light emitting display device that minimizes errors in sensing values due to power ripple applied when sensing characteristics of a driving transistor included in a subpixel disposed in an organic light emitting display panel.

The purpose of the present embodiments is to prevent incorrect compensation of the characteristic value of the driving transistor due to power ripple applied when sensing the characteristic value of the driving transistor included in the subpixel disposed on the organic light emitting display panel, and to prevent screen defects due to incorrect compensation. The goal is to provide an organic light emitting display device that prevents this from occurring.

In one embodiment, N (N ≥ 2) gate lines and M (M ≥ 2) data lines are arranged to intersect, and a plurality of subpixels including organic light-emitting diodes and driving transistors for driving the organic light-emitting diodes are arranged. The characteristics of the organic light emitting display panel, the gate driver driving N gate lines, the data driver driving M data lines, and the driving transistor are sensed for each gate line, and the same driving transistor is sensed in a separate sensing section. An organic light emitting display device can be provided including a sensing unit that generates one sensing data for the characteristic value of a driving transistor using one or more sensing values.

In such an organic light emitting display device, the sensing unit generates sensing data for the characteristic values of the driving transistor using the average value of two or more sensing values for the characteristic values of the driving transistor, or generates the maximum and minimum values from three or more sensing values for the characteristic values of the driving transistor. Generates sensing data for the characteristic value of the driving transistor using the average value of the remaining sensing values, or senses the characteristic value of the driving transistor as many times as a multiple of the ratio of the number of subpixels and the number of sensing lines that sense the characteristic value of the driving transistor. And using the sensed value, a single sensing data for the characteristic value of the driving transistor can be generated.

In such an organic light emitting display device, the sensing unit senses the characteristic value of the driving transistor N times in a separate sensing section and performs the Sensing data for the characteristic value of the driving transistor is generated as a value, or the characteristic value of the driving transistor is sensed M times in a separate sensing section and the driving transistor included in the subpixel driven by the data line in the Y (1≤Y≤M) row is generated. Sensing data for the characteristic values of the driving transistor can be generated using the Yth sensing value of the transistor.

Another embodiment is an organic light emitting display panel including an organic light emitting display panel in which a plurality of gate lines and a plurality of data lines are arranged to intersect and a plurality of subpixels including an organic light emitting diode and a driving transistor for driving the organic light emitting diode are arranged. A method of driving a display device includes the steps of sequentially sensing the characteristic value of a driving transistor for each gate line, and using two or more sensing values sensed in separate sensing sections for the same driving transistor to determine one characteristic value of the driving transistor. A method of driving an organic light emitting display device including generating sensing data can be provided.

According to the present embodiments, by changing the method of sensing the characteristic value of the driving transistor included in the subpixel disposed in the organic light emitting display panel, the influence of the ripple of the power applied when sensing the characteristic value of the driving transistor can be minimized.

According to the present embodiments, the influence of power ripple applied when sensing the characteristic values of the driving transistor included in the subpixel disposed on the organic light emitting display panel is minimized, thereby preventing screen defects such as horizontal lines due to compensation based on incorrect sensing values. Prevent this from happening.

1 is a diagram showing a schematic configuration of an organic light emitting display device according to the present embodiments.
Figure 2 is a diagram showing an example of a subpixel structure of an organic light emitting display device according to the present embodiments.
Figure 3 is a diagram showing an example of a subpixel structure and compensation circuit of an organic light emitting display device according to the present embodiments.
Figures 4 and 5 are diagrams to explain sensing of characteristics of a driving transistor within a subpixel of an organic light emitting display device according to the present embodiments.
FIG. 6 is a diagram illustrating a section for sensing characteristic values of a driving transistor within a subpixel of an organic light emitting display device according to the present embodiments.
FIG. 7 is a diagram illustrating errors and screen defects caused by power ripple applied when sensing characteristic values of a driving transistor within a subpixel of an organic light emitting display device according to the present embodiments.
Figures 8 and 9 are diagrams showing examples of a method for sensing characteristic values of a driving transistor within a subpixel of an organic light emitting display device according to the present embodiments.
10 and 11 are flowcharts showing the process of the driving method of the 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 the exemplary drawings. In adding reference numerals to components in each drawing, identical components may have the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when 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.

Additionally, when describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the essence, sequence, order, or number of the components are not limited by the term. When a component is described as being “connected,” “coupled,” or “connected” to another component, that component may be directly connected or connected to that other component, but there are no other components between each component. It should be understood that may be “interposed” or that each component may be “connected,” “combined,” or “connected” through other components.

Figure 1 shows a schematic configuration 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 has multiple (N, N≥2) gate lines (GL) and multiple (M, M=4m≥2) data. An organic light emitting display panel 110 including a plurality of subpixels (SP) disposed in an area where a line (DL) is disposed and a gate line (GL) and a data line (DL) intersect, and a plurality of gate lines (GL) ), a gate driver 120 for driving, a data driver 130 for supplying data voltages to a plurality of data lines DL, and a timing controller 140 for controlling the gate driver 120 and the data driver 130. Includes T-CON).

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

The gate driver 120 sequentially supplies scan signals of the ON voltage or OFF voltage to the plurality of gate lines GL according to the control of the timing controller 140. are operated sequentially.

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

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

Each gate driver integrated circuit is connected to a bonding pad of the organic light emitting display panel 110 using a tape automated bonding (TAB) method or a chip on glass (COG) method. It is implemented as a GIP (Gate In Panel) type and can be placed directly on the organic light emitting display panel 110. Additionally, it may be integrated and disposed on the organic light emitting display panel 110, or may be implemented using a chip on film (COF) method mounted on a film connected to the organic light emitting display panel 110.

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

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

The data driver 130 may include at least one source driver integrated circuit and drive multiple data lines DL.

Each source driver integrated circuit is connected to a bonding pad of the organic light emitting display panel 110 using a tape automated bonding (TAB) method or a chip on glass (COG) method. It may be placed directly on the organic light emitting display panel 110, or may be integrated and placed on the organic light emitting display panel 110.

Additionally, each source driver integrated circuit may be implemented in a chip on film (COF: Chip On Film) method. In this case, one end of each source driver integrated circuit is bonded to at least one source printed circuit board (Source Printed Circuit Board), and the other end is bonded to the organic light emitting display panel 110.

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

The timing controller 140 starts scanning according to the timing implemented in each frame, converts the input image data input from the outside to fit the data signal format used by the data driver 130, and outputs the converted image data. And data drive is controlled at an appropriate time according to the scan.

The timing controller 140 provides various timing signals including a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), an input data enable (DE) signal, and a clock signal (CLK) along with input image data. Receive data from external sources (e.g. host system).

The timing controller 140 converts the input image data input from the outside to suit the data signal format used by the data driver 130 and outputs the converted image data, as well as the gate driver 120 and the data driver 130. ), the gate driver receives timing signals such as the vertical synchronization signal (Vsync), horizontal synchronization signal (Hsync), input data enable signal (DE), and clock signal (CLK) to generate various control signals. It is output to (120) and data driver (130).

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

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

Additionally, the timing controller 140 uses a source start pulse (SSP), a source sampling clock (SSC), and a source output enable signal (SOE) to control the data driver 130. Outputs various data control signals (DCS: Data Control Signal) including Output Enable.

Here, the source start pulse (SSP) controls the data sampling start timing of one or more source driver integrated circuits constituting the data driver 130. The source sampling clock (SSC) is a clock signal that controls the sampling timing of data in each source driver integrated circuit. The source output enable signal (SOE) controls the output timing of the data driver 130.

The timing controller 140 is a control printed circuit connected to a source printed circuit board to which a source driver integrated circuit is bonded through a connection medium such as a flexible flat cable (FFC: Flexible Flat Cable) or a flexible printed circuit (FPC: Flexible Printed Circuit). It can be placed on a control printed circuit board.

This control printed circuit board includes a power controller (not shown) that supplies various voltages or currents to the organic light emitting display panel 110, gate driver 120, and data driver 130, or controls various voltages or currents to be supplied. More could be arranged. This power controller is also called a Power Management Integrated Circuit.

Each subpixel (SP) disposed on the organic light emitting display panel 110 may be configured to include a circuit element such as a transistor.

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

The type and number of circuit elements constituting each subpixel (SP) can be determined in various ways depending on the provided function and design method.

Figure 2 shows an example of the subpixel (SP) structure of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 2, in the organic light emitting display device 100 according to the present embodiments, each subpixel (SP) includes an organic light emitting diode (OLED) and a driving transistor (DRT) that drives the organic light emitting diode (OLED). ) and a sensing transistor (SENT: Sensing Transistor) electrically connected between the first node (N1) of the driving transistor (DRT) and the reference voltage line (RVL: Reference Voltage Line) that supplies the reference voltage (Vref: Reference Voltage) ), a switching transistor (SWT: Switching Transistor) electrically connected between the second node (N2) of the driving transistor (DRT) and the data line (DL) that supplies the data voltage (Vdata), and a driving transistor (DRT) It is composed of a storage capacitor (Cstg: Storage Capacitor) electrically connected between the first node (N1) and the second node (N2).

An organic light-emitting diode (OLED) may be composed of a first electrode (eg, an anode electrode or cathode electrode), an organic layer, and a second electrode (eg, a cathode electrode or 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 the source node or drain node of the switching transistor SWT and may be a gate node. The third node (N3) of the driving transistor (DRT) may be electrically connected to a driving voltage line (DVL) that supplies the driving voltage (EVDD) and may be a drain node or a source node.

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

Additionally, the sensing transistor (SENT) may be used as a voltage sensing path for the first node (N1) of the driving transistor (DRT) when turned on.

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

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

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

Meanwhile, in the case of the organic light emitting display device 100 according to the present embodiments, as the driving time of each subpixel (SP) increases, circuit elements such as the organic light emitting diode (OLED) and driving transistor (DRT) increase. Degradation may occur.

Accordingly, the unique characteristics (e.g., threshold voltage, mobility, etc.) of circuit elements such as organic light-emitting diodes (OLEDs) and driving transistors (DRTs) may change.

Changes in the characteristic values of these circuit elements cause changes in the luminance of the corresponding subpixel (SP), and differences in characteristic changes between circuit elements due to differences in the degree of deterioration between the circuit elements cause luminance deviations between the subpixels (SP) and organic light emitting display. This may result in a decrease in luminance uniformity of the panel 110.

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

The organic light emitting display device 100 according to the present embodiments includes a sensing function that senses a change in characteristic value between subpixels (SP) or a deviation in characteristic value between each subpixel (SP), and a sensing function that senses a change in characteristic value between subpixels (SP), and a sensing function that senses a change in characteristic value between subpixels (SP), and a sensing function that senses a change in characteristic value between subpixels (SP). A compensation function that compensates for the characteristic values of can be provided.

FIG. 3 shows an example of a subpixel (SP) structure and compensation circuit 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 sensing unit 310, a compensation unit 320, a memory 330, and It may include a reference voltage switch (SPRE) and a sampling switch (SAMP).

The sensing unit 310 senses a voltage for sensing the characteristic value of the subpixel (SP) or its change, converts the sensed voltage into a digital value, and outputs sensing data including the converted sensing value.

Here, the characteristic value of the subpixel (SP) refers to the threshold voltage and mobility of the driving transistor (DRT) or the threshold voltage of the organic light emitting diode (OLED), and the sensing data is in the LVDS (Low Voltage Differential Signaling) data format. You can.

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

The compensation unit 320 uses the sensing data output by the sensing unit 310 to determine the characteristic value of the subpixel (SP) or its change, and performs a compensation process to compensate for the difference in characteristic values between the subpixels (SP).

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

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

The reference voltage switch (SPRE) controls whether or not the reference voltage (Vref) is supplied to the reference voltage line (RVL), and the sampling switch (SAMP) controls the reference voltage to sense the characteristic value of the subpixel (SP). Controls the connection between the voltage line (RVL) and the sensing unit 310.

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

Meanwhile, when the voltage of the first node (N1) of the driving transistor (DRT) is in a voltage state that reflects the characteristic value of the subpixel (SP), the reference that may be at equal potential with the first node (N1) of the driving transistor (DRT) The voltage of the voltage line RVL may also be in a voltage state that reflects the characteristic value of the subpixel SP. At this time, the line capacitor formed on the reference voltage line RVL may be charged with a voltage reflecting the characteristic value of the subpixel SP.

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

When the voltage of the first node (N1) of the driving transistor (DRT) becomes a voltage state that reflects the characteristic value of the subpixel (SP), the sampling switch (SAMP) is turned on, and the sensing unit 310 and the reference voltage line (RVL) can be connected.

Accordingly, the sensing unit 310 senses the voltage of the reference voltage line (RVL), which is a voltage state that reflects the characteristic value of the subpixel (SP). Here, the reference voltage line (RVL) may be referred to as a “sensing line (SL).”

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

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

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

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

Below, the threshold voltage sensing process and mobility sensing process of the driving transistor (DRT) will be described with reference to FIGS. 4 and 5.

FIG. 4 is a diagram illustrating a method for sensing the threshold voltage of the driving transistor (DRT) of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 4, when driving the threshold voltage sensing of the driving transistor (DRT), the first node (N1) and the second node (N2) of the driving transistor (DRT) are respectively a reference voltage (Vref) and a data voltage for sensing ( Vdata).

Afterwards, when the reference voltage switch (SPRE) is turned off, the first node (N1) of the driving transistor (DRT) is floating.

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) increases, then gradually decreases and becomes saturated.

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

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

The voltage (Vsen) sensed by the sensing unit 310 is a voltage (Vdata-Vth) obtained by subtracting the threshold voltage (Vth) from the data voltage (Vdata), or a voltage obtained by subtracting the threshold voltage deviation (ΔVth) from the data voltage (Vdata). It may be (Vdata-ΔVth).

FIG. 5 is a diagram for explaining a method of sensing the mobility of the driving transistor (DRT) of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 5, when driving the mobility sensing of the driving transistor (DRT), the first node (N1) and the second node (N2) of the driving transistor (DRT) are respectively connected to a reference voltage (Vref) and a data voltage for sensing ( Vdata).

Thereafter, when the reference voltage switch (SPRE) is turned off, the first node (N1) of the driving transistor (DRT) is floated. At this time, the switching transistor (SWT) is turned off, and the second node (N2) of the driving transistor (DRT) may also be floating.

Accordingly, the voltage of the first node (N1) of the driving transistor (DRT) begins to rise.

During a certain period of time, the voltage increase amplitude (ΔV) of the first node (N1) of the driving transistor (DRT) is the rate of voltage increase and varies depending on the current capability, that is, mobility, of the driving transistor (DRT).

That is, the higher the current capability (mobility) of the driving transistor (DRT), the more steeply the voltage of the first node (N1) of the driving transistor (DRT) rises, so that the voltage of the first node (N1) of the driving transistor (DRT) rises more steeply for a certain period of time. ) has a large voltage increase (ΔV).

After the voltage of the first node (N1) of the driving transistor (DRT) increases for a predetermined period of time, the sensing unit 310 senses the increased voltage of the first node (N1) of the driving transistor (DRT). .

The rate of change per hour, that is, the slope, of the voltage rise width (ΔV) according to the voltage (Vsen) sensed by the sensing unit 310 may be mobility.

The sensing unit 310 converts the sensed voltage (Vsen) into a digital value according to the above-described threshold voltage or mobility sensing drive, and generates and outputs sensing data including the converted sensing value. Sensing data output from the sensing unit 310 may be stored in the memory 330 or provided to the compensation unit 320.

The compensation unit 320 determines the characteristic value or change in characteristic value of the driving transistor (DRT) in the corresponding subpixel (SP) based on the sensing data provided by the sensing unit 310 or the sensing data stored in the memory 330 and calculates the characteristic value deviation. Perform a process to compensate.

The characteristic value compensation process may include a threshold voltage compensation process that compensates for the threshold voltage of the driving transistor (DRT) and a mobility compensation process that compensates for the mobility of the drive transistor (DRT).

The threshold voltage compensation process may include calculating a compensation value to compensate for the threshold voltage or threshold voltage deviation, storing the calculated compensation value in the memory 330, or changing the corresponding image data with the calculated compensation value. there is.

Mobility compensation processing may include calculating a compensation value to compensate for mobility or mobility deviation, storing the calculated compensation value in the memory 330, or changing the corresponding image data with the calculated compensation value. You can.

The compensator 320 may change image data through threshold voltage compensation processing or mobility compensation processing and supply the changed data to the corresponding source driver integrated circuit within the data driver 130.

Accordingly, the source driver integrated circuit converts the data changed in the compensation unit 320 into a data voltage through a digital to analog converter (DAC: Digital to Analog Converter) and supplies it to the corresponding subpixel (SP). SP) ensures that compensation is made for the characteristic values.

As the characteristics of the subpixels (SP) are compensated, the luminance deviation between the subpixels (SPs) is reduced or prevented, thereby increasing the luminance uniformity of the organic light emitting display panel 110 and improving image quality.

FIG. 6 is a diagram showing timing for sensing subpixel (SP) characteristic values of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 6, in the organic light emitting display device 100 according to the present embodiments, after a power-off signal is generated according to a user input, etc., within each subpixel (SP) disposed on the organic light emitting display panel 110. The characteristic values of circuit elements can be sensed.

In this way, the sensing that proceeds after the generation of the power-off signal is called “off-sensing.”

In addition, the organic light emitting display device 100 according to the present embodiments, after a power-on signal is generated according to a user input, etc., before image operation begins, each subpixel ( SP) You can sense the characteristics of my circuit elements.

In this way, sensing that occurs after generation of the power-off signal but before image driving is called “on-sensing.”

Additionally, the organic light emitting display device 100 according to the present embodiments may sense characteristic values of circuit elements within each subpixel (SP) disposed on the organic light emitting display panel 110 during image driving.

In this way, sensing that occurs during video operation is called “real-time sensing.”

This real-time sensing may be performed every blank time between active times based on the vertical synchronization signal (Vsync).

Sensing the threshold voltage of the driving transistor (DRT) while sensing the characteristic value of the subpixel (SP) senses the voltage in the saturated state of the first node (N1) of the driving transistor (DRT) in the sensing section, so that the Since a certain amount of time is required for one node (N1) to become saturated, it can be performed in an off-sensing manner.

Since the mobility of the driving transistor (DRT) can be sensed within a relatively short period of time, it can be performed using a real-time sensing method using the blank time during image driving.

Meanwhile, in the process of sensing the characteristics of the driving transistor (DRT), ripples may occur in power supplies such as the sensing data voltage (Vdata) or reference voltage (Vref) applied to sense the characteristics of the driving transistor (DRT). There is a number.

When ripple occurs in the power applied to sense the characteristics of the driving transistor (DRT), the power ripple affects the voltage sensed at the first node (N1) of the driving transistor (DRT), causing the sensed first node ( Sensing data generated based on the voltage of N1) may contain an error (Error Term).

Errors in the sensing data are reflected in the compensation value calculated based on the sensing data, resulting in incorrect compensation for the characteristics of the driving transistor (DRT), which may appear as a defective screen after compensation.

FIG. 7 shows an example of a screen defect that occurs due to ripple of power applied when sensing the characteristic value of the driving transistor (DRT) in the subpixel (SP) of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 7, when ripple occurs in the power applied when sensing the characteristic value of the driving transistor (DRT), the power ripple affects the voltage sensed by the sensing unit 310, and the sensing unit 310 includes an error. This generates sensing data that

When the sensing unit 310 outputs the sensing data for the characteristic value of the driving transistor (DRT) at a larger value than that of the peripheral part due to the influence of power ripple, the compensation unit 320 outputs the sensing data for the characteristic value of the driving transistor (DRT) at a larger value than the surrounding area. The compensation value for is calculated to be small. Accordingly, since compensation for the characteristic value of the driving transistor (DRT) is small, the subpixel (SP) including the driving transistor (DRT) may appear as a dark spot after compensation.

When the sensing unit 310 outputs the sensing data for the characteristic value of the driving transistor (DRT) at a smaller value than that of the peripheral part due to the influence of power ripple, the compensation unit 320 outputs the sensing data for the characteristic value of the driving transistor (DRT) at a smaller value than that of the peripheral part. Since the compensation value for is calculated to be large, the subpixel (SP) including the driving transistor (DRT) may appear as a bright spot after compensation.

Since sensing of the characteristics of the driving transistor (DRT) is performed for each gate line (GL) arranged on the organic light emitting display panel 110, dark spots or bright spots resulting from compensation based on sensing data including errors are detected by the gate line (GL). It appears in the form of a dark line or a bright line, and is recognized as a screen defect in the form of a horizontal line.

In the present embodiments, in sensing the characteristic value of the driving transistor (DRT) in the subpixel (SP) and performing compensation for the characteristic value of the driving transistor (DRT) based on the sensed value, sensing due to power ripple applied during sensing To prevent data errors and screen defects caused by those errors, sensing data on the characteristics of the driving transistor (DRT) can be generated through various sensing methods.

8 and 9 show an example of a method for sensing the characteristic value of the driving transistor (DRT) in the subpixel (SP) of the organic light emitting display device 100 according to the present embodiments, and the characteristic value of the driving transistor (DRT) Provides a sensing method that can minimize errors in sensing data due to power ripple applied during sensing by generating one sensing data using two or more sensing values.

Referring to FIG. 8, the organic light emitting display device 100 according to the present embodiments senses the characteristic value of the driving transistor (DRT) in the subpixel (SP) more than twice and uses the average value of the values sensed more than twice. A single sensing data for the characteristic value of the corresponding driving transistor (DRT) can be generated.

For example, the sensing unit 310 performs sensing for each gate line (GL) in a section that senses the characteristic value of the driving transistor (DRT) and stores the sensed value in the first sensing section. Then, a second sensing is performed on the characteristic value of the driving transistor (DRT) in a separate sensing section, and the value sensed in the second sensing section is stored.

The sensing unit 310 calculates the average value of the values sensed in the first sensing section and the value sensed in the second sensing section, and generates one sensing data for the characteristic value of the driving transistor (DRT) with the calculated average value. .

This takes advantage of the fact that the error in the sensing value due to power ripple does not occur repeatedly in the same gate line (GL), and generates one sensing data as the average value of two or more sensing values sensed in separate sensing sections, thereby increasing the sensing value. To minimize the impact of errors.

As shown in the example shown in FIG. 8, even if there is an error in the sensed value due to power ripple in the value sensed in the first sensing section and the value sensed in the second sensing section, sensing is performed by generating sensing data as the average value of the two sensing values. The influence of value errors can be eliminated.

In order to further reduce the error in the sensing value due to power ripple, the number of times to sense the characteristic value of the driving transistor (DRT) is increased and the sensing data is generated with the average value of the obtained sensing values, thereby reducing the error in the sensing value due to power ripple. The impact on data can be further reduced.

At this time, even if the number of sensing increases, the number of errors in the sensing value due to power ripple also increases as the number of sensing increases, so even if the sensing data is generated using the average value of several sensing values, there may be an error in the generated sensing data due to power ripple. The influence of value errors may remain.

Therefore, in generating one sensing data for the characteristic value of the driving transistor (DRT) with the average value of a plurality of sensing values sensed in a separate sensing section, the average value of the remaining sensing values excluding the maximum and minimum values among the plurality of sensing values You can also generate a single sensing data using .

In other words, when sensing the characteristic value of the driving transistor (DRT), the sensing data for the characteristic value of the driving transistor (DRT) is generated by excluding the sensing value that is expected to have an error due to the ripple of the applied power and using the remaining sensing values. It is possible to minimize the impact of value errors and improve the reliability of the generated sensing data.

Meanwhile, the sensing line (SL) for sensing the characteristic value of the driving transistor (DRT) within the subpixel (SP) disposed on the organic light emitting display panel 110 may be disposed for each subpixel (SP), but one The sensing line (SL) may be connected to two or more subpixels (SP) to sense the characteristic value of the driving transistor (DRT) included in the subpixel (SP).

In this case, in order to sense the characteristic value of each driving transistor (DRT), sensing must be performed a number of times corresponding to the number of subpixels (SP) connected to one sensing line (SL). Sensing values for the driving transistor (DRT) can be obtained.

Therefore, in order to generate one sensing data using two or more sensing values for the characteristic values of the driving transistor (DRT), the number of times corresponding to a multiple of the number of subpixels (SP) connected to one sensing line (SL) Sensing must be performed to obtain two or more sensing values for the characteristic values of the driving transistor (DRT) included in each subpixel (SP).

In the present embodiments, when there is more than one subpixel (SP) connected to the sensing line (SL) that senses the characteristic value of the driving transistor (DRT), the number of subpixels (SP) connected to one sensing line (SL) is The characteristic value of the driving transistor (DRT) is sensed a number of times corresponding to the multiple, and one sensing data is generated using the obtained sensing value.

Therefore, even in a structure where two or more subpixels (SP) are connected to one sensing line (SL), one sensing data is generated using two or more sensing values for the characteristic values of each driving transistor (DRT), so that the driving transistor (DRT) When sensing the characteristic value of DRT), it is possible to minimize the influence of errors in the sensing value due to the ripple of the applied power.

FIG. 9 shows another example of a method for sensing characteristics of a driving transistor (DRT) within a subpixel (SP) of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 9, the sensing unit 310 senses the characteristic value of the driving transistor (DRT) in a separate sensing section a number of times corresponding to the number of gate lines (GL) disposed on the organic light emitting display panel 110. , sensing data about the characteristics of the driving transistor (DRT) can be generated by combining the sensed values.

That is, the sensing unit 310 acquires a sensing value corresponding to the number of gate lines GL disposed on the organic light emitting display panel 110 in a separate sensing section, and selects one of the values sensed in each sensing section. After extracting the sensing value for the characteristics of the driving transistor (DRT) included in the subpixel (SP) driven by one gate line (GL), one sensing data can be generated using the extracted sensing value.

As an example, sensing is performed N times on the organic light emitting display panel 110 on which N gate lines (GL) are arranged, and the driving transistor ( The Xth sensing value for the characteristic value of the DRT can be generated as sensing data for the characteristic value of the corresponding driving transistor (DRT).

Specifically, when N gate lines (GL) are arranged in the organic light emitting display panel 110, the sensing unit 310 performs sensing of the characteristic value of the driving transistor (DRT) N times in separate sensing sections. .

The sensing unit 310 is a driving transistor (DRT) included in the subpixel (SP) driven by the first gate line (GL) disposed on the organic light emitting display panel 110 among the values sensed in the first sensing section. Extract sensing values for characteristic values.

Among the values sensed in the second sensing section, the sensed value for the characteristic value of the driving transistor (DRT) included in the subpixel (SP) driven by the second gate line (GL) disposed on the organic light emitting display panel 110 Extract .

In the same way, among the values sensed in the third sensing section, the characteristic value of the driving transistor (DRT) included in the subpixel (SP) driven by the third gate line (GL) disposed on the organic light emitting display panel 110 By extracting the sensing value for and repeating the above-mentioned process, among the values sensed in the Nth sensing section, the subpixel (SP) driven by the Nth gate line (GL) disposed on the organic light emitting display panel 110 ) extracts the sensing value for the characteristics of the driving transistor (DRT) included in the

While sensing the characteristic value of the driving transistor (DRT) N times, the sensing unit 310 detects the driving transistor included in the subpixel (SP) driven by one gate line (GL) extracted in each sensing section. Sensing data for the characteristics of the driving transistor (DRT) is generated using the sensing values for the characteristics of the DRT. In other words, this method generates one sensing data by combining the sensing values extracted during N sensing times.

As in the above-mentioned method, N times of sensing is performed by extracting only the sensing value of the characteristic value of the driving transistor (DRT) included in the subpixel (SP) driven by one gate line (GL) in each sensing section. By generating a single sensing data from the sensed values, it is possible to exclude sensing values with errors due to power ripple from the sensing data as much as possible.

That is, by extracting the sensing value for the characteristic value of the driving transistor (DRT) included in the subpixel (SP) driven by one gate line (GL) among the values sensed in one sensing section, (N-1) Sensing values for the characteristics of the driving transistor (DRT) included in the subpixel (SP) driven by the gate lines (GL) are excluded from the sensing data, and in this process, the sensing values with errors due to power ripple are excluded from the sensing data. Enables sensing data to be generated only from sensing values that are not included.

In another example, sensing the characteristic value of the driving transistor (DRT) is performed a number of times corresponding to the number of data lines (DL) disposed on the organic light emitting display panel 110, and among the sensing values obtained in the Yth sensing, Y Only the sensing values for the characteristic values of the driving transistor (DRT) included in the subpixel (SP) driven by the data line (DL) of the column are extracted and the extracted sensing values are combined to form one characteristic value for the driving transistor (DRT). Sensing data can also be generated.

For example, among the values sensed for the characteristic values of the driving transistor (DRT) in the first sensing section, sensing the characteristic value of the driving transistor (DRT) included in the subpixel (SP) driven by the first data line (DL) The value is extracted, and among the values sensed as the characteristic values of the driving transistor (DRT) in the second sensing section, the characteristic values of the driving transistor (DRT) included in the subpixel (SP) driven by the second data line (DL) are selected. Extract the sensing value for

In the same way, by repeating the sensing of the characteristic value of the driving transistor (DRT) and the extraction of the sensing value, the subpixel (SP) driven by one data line (DL) in each sensing section while performing M sensing ) extracts the sensing value for the characteristics of the driving transistor (DRT) included in the sensor and generates one sensing data using the extracted sensing value.

Therefore, among the values sensed in the sensing section, only the sensed value for the characteristic value of the driving transistor (DRT) included in the subpixel (SP) driven by one of the data lines (DL) is extracted, and the remaining (M-1) By excluding from the sensing data the sensing values for the characteristics of the driving transistor (DRT) included in the subpixel (SP) driven by the data lines (DL), the sensing values with errors due to power ripple are excluded from the sensing data. By doing so, the impact of errors in sensing values can be minimized and the reliability of the sensing data can be improved.

Figures 10 and 11 show the process of the driving method of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 10, the sensing unit 310 of the organic light emitting display device 100 according to the present embodiments senses the characteristic value of the driving transistor (DRT) in the section where the characteristic value of the driving transistor (DRT) is sensed ( S1000).

The sensing unit 310 performs sensing of the characteristic value of the driving transistor (DRT) in another sensing section (S1010).

The sensing unit 310 accumulates sensing values for the same driving transistor (DRT) sensed in separate sensing sections (S1020) and calculates the average value of the accumulated sensing values (S1030).

The sensing unit 310 may calculate an average value from two or more accumulated sensing values, or may calculate an average value from the remaining sensing values excluding the maximum and minimum values from three or more sensing values.

The sensing unit 310 generates one sensing data for the characteristic value of the corresponding driving transistor (DRT) as the average value of two or more sensing values sensed in separate sections (S1040).

Therefore, in generating sensing data for the characteristic value of the driving transistor (DRT), one sensing data for the characteristic value of the driving transistor (DRT) is generated as the average value of two or more sensing values sensed in separate sensing sections, thereby driving When sensing the characteristics of a transistor (DRT), the error in the sensing value caused by the ripple of the applied power can minimize the impact on the sensing data.

Referring to FIG. 11, the sensing unit 310 of the organic light emitting display device 100 according to the present embodiments is a subpixel (SP) of the organic light emitting display panel 110 on which N gate lines (GL) are arranged. The characteristic value of my driving transistor (DRT) can be sensed N times and one sensing data can be generated using the N sensed values.

The sensing unit 310 sets X to 1 in the first sensing section (S1100) and performs sensing of the characteristic value of the driving transistor (DRT) (S1110).

Among the sensing values for the characteristic values of the driving transistor (DRT) sensed in the first sensing section, the sensing value for the characteristic value of the driving transistor (DRT) included in the subpixel (SP) driven by the first gate line (GL) is Extract (S1120).

The sensing unit 310 increases X by 1 (S1130), compares Repeat the above process until it is done.

That is, in the second sensing section, among the sensing values for the characteristic values of the driving transistor (DRT), the sensing value for the characteristic value of the driving transistor (DRT) included in the subpixel (SP) driven by the second gate line (GL) Extract and repeat this process, and in the Nth sensing section, the driving transistor (DRT) included in the subpixel (SP) driven by the Nth gate line (GL) among the sensing values for the characteristic values of the driving transistor (DRT). ) Extract the sensing value for the characteristic value.

When N times of sensing is completed, the sensing unit 310 generates sensing data about the characteristic value of the driving transistor (DRT) using the sensing value extracted from each sensing section (S1150).

Therefore, in each sensing section, only the sensing value of the driving transistor (DRT) included in the subpixel (SP) driven by one gate line (GL) is extracted and the remaining (N-1) gate lines (GL) are extracted. Sensing values for the characteristics of the driving transistor (DRT) included in the subpixel (SP) driven by are excluded from the sensing data, so that sensing values with errors due to power ripple can be excluded from the sensing data.

According to these embodiments, the average value of two or more sensing values sensed in separate sensing sections is generated as sensing data, or the average value of two or more sensing values sensed in separate sensing sections is generated as sensing data, or the average value of two or more sensing values sensed in separate sensing sections is generated as sensing data, or the average value of two or more sensing values sensed in separate sensing sections is generated as sensing data, or the average value of two or more sensing values sensed in separate sensing sections is generated as sensing data, or the average value of two or more sensing values sensed in separate sensing sections is generated as sensing data, or By generating sensing data by extracting only the sensing values for the included driving transistor (DRT), generating sensing data that minimizes the impact of sensing values that have errors due to the ripple of the applied power when sensing the characteristic values of the driving transistor (DRT). make it possible

Through this, incorrect compensation due to an error in the sensing value of the driving transistor (DRT) is not performed, and screen defects such as horizontal lines caused by incorrect compensation for the characteristic value of the driving transistor (DRT) are prevented from occurring.

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

100: Organic light emitting display device 110: Organic light emitting display panel
120: gate driver 130: data driver
140: timing controller 310: sensing unit
320: Compensation unit 330: Memory

Claims (12)

An organic light emitting device in which N (N ≥ 2) gate lines and M (M ≥ 2) data lines are arranged to intersect, and a plurality of subpixels including organic light emitting diodes and driving transistors for driving the organic light emitting diodes are arranged. display panel;
a gate driver driving the N gate lines;
a data driver driving the M data lines;
a sensing unit that senses the characteristic value of the driving transistor for each gate line and generates one sensing data for the characteristic value of the driving transistor using two or more sensing values sensed for the same driving transistor in separate sensing sections; and
A compensation unit that generates a compensation value for the characteristic value of the driving transistor based on sensing data generated based on two or more sensing values sensed in separate sensing sections.
Includes,
The sensing unit,
Sensing data for the characteristic value of the driving transistor is generated as the average value of two or more sensing values for the characteristic value of the driving transistor, and the average value of the remaining sensing values excluding the maximum and minimum values from the three or more sensing values for the characteristic value of the driving transistor are generated. An organic light emitting display device that generates sensing data about characteristics of the driving transistor.
delete delete According to paragraph 1,
The sensing unit,
Sensing the characteristic value of the driving transistor a number of times corresponding to a multiple of the ratio of the number of subpixels and the number of sensing lines that sense the characteristic value of the driving transistor, and using the sensed value to determine one characteristic value of the driving transistor. An organic light emitting display device that generates sensing data.
delete delete delete delete Driving an organic light emitting display device including an organic light emitting display panel in which a plurality of gate lines and a plurality of data lines are intersected and a plurality of subpixels including organic light emitting diodes and driving transistors for driving the organic light emitting diodes are arranged. In the method,
sequentially sensing characteristic values of the driving transistor for each gate line;
Generating one sensing data for the characteristic value of the driving transistor using two or more sensing values sensed in separate sensing sections for the same driving transistor; and
Generating a compensation value for the characteristic value of the driving transistor based on sensing data generated based on two or more sensing values sensed in separate sensing sections.
Includes,
The step of generating one sensing data for the characteristic value of the driving transistor is:
Sensing data for the characteristic value of the driving transistor is generated as the average value of two or more sensing values sensed in separate sensing sections, excluding the maximum and minimum values from three or more sensing values for the characteristic value of the driving transistor. A method of driving an organic light emitting display device that generates sensing data about the characteristic value of the driving transistor using the average value of the remaining sensing values. delete delete delete

Images