KR102536619B1 - Driving circuit, organic light emitting display device, and driving method - Google Patents

Abstract

Embodiments of the present invention relate to a driving circuit, an organic light emitting display device, and a driving method, and more specifically, the threshold voltage of a transistor can be sensed in real time during image driving, and furthermore, the threshold voltage and mobility can be simultaneously sensed. It relates to a driving circuit capable of real-time sensing, an organic light emitting display device, and a driving method. According to the embodiments of the present invention, it is possible to immediately compensate for a change in threshold voltage during image driving, and to simultaneously sense the threshold voltage and mobility in the same sensing-driving process, thereby reducing the time or number of times required for the sensing-driving process. There are possible effects.

Description

Driving circuit, organic light emitting display device and driving method

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

Recently, an organic light emitting display device that has been in the limelight as a display device uses an organic light emitting diode (OLED) that emits light by itself, and has advantages such as fast response speed, luminous efficiency, luminance, and viewing angle.

An organic light emitting display device arranges organic light emitting diodes and subpixels including driving transistors for driving them in a matrix form, and controls brightness of subpixels selected by a scan signal according to grayscale of data.

In the case of an organic light emitting display device, an organic light emitting diode and a driving transistor for driving the organic light emitting diode are disposed in each subpixel defined on the display panel. Depending on , or due to a difference in driving time of each sub-pixel, a characteristic value deviation between each transistor may occur. Due to this, luminance deviation (luminance non-uniformity) between subpixels may occur, and image quality may deteriorate.

In the case of a conventional organic light emitting display device, a sensing and compensation technique for sensing and compensating for a characteristic value deviation between driving transistors has been proposed in order to solve a luminance deviation between subpixels. However, due to various conditions, such as lack of sensing time, there is a situation in which normal sensing drive cannot be performed or accurate sensing values cannot be obtained. In this case, a situation in which image quality may be deteriorated may occur. .

An object of embodiments of the present invention is to provide a driving circuit, an organic light emitting display device, and a driving method that enable accurate sensing and compensation while reducing the time required for sensing.

Another object of the embodiments of the present invention is to provide a driving circuit capable of sensing a threshold voltage of a transistor in real time during image driving, an organic light emitting display device, and a driving method.

Another object of the embodiments of the present invention is to provide a driving circuit capable of simultaneously sensing a threshold voltage and mobility of a transistor in real time during image driving, an organic light emitting display device, and a driving method.

In one aspect, embodiments of the present invention drive a plurality of data lines, a display panel on which a plurality of data lines, a plurality of gate lines, a plurality of reference voltage lines, and a plurality of subpixels are arranged. It is possible to provide an organic light emitting display device including a data driving circuit for driving and a gate driving circuit for driving a plurality of gate lines.

A plurality of subpixels includes an organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first transistor electrically connected between a first node of the driving transistor and a corresponding data line among a plurality of data lines, and a driving transistor. It may include a second transistor electrically connected between the second node and a corresponding reference voltage line among the plurality of reference voltage lines, and a capacitor electrically connected between the first node and the second node of the driving transistor.

An organic light emitting display device includes a sensing drive reference switch electrically connected between a reference voltage supply node and a reference voltage line, an analog-to-digital converter that senses a voltage of the reference voltage line, and an electrical connection between the reference voltage line and the analog-to-digital converter. A connected sampling switch may be further included.

A drain node or a source node of a second transistor included in any first subpixel among a plurality of subpixels may be electrically connected to a first reference voltage line among a plurality of reference voltage lines.

A drain node or a source node of the first transistor included in the first subpixel may be electrically connected to a first data line among a plurality of data lines.

During the initialization period of the first sensing driving period, a first reference voltage may be applied to the first reference voltage line. Also, during the initialization period of the first sensing driving period, the data voltage for the first sensing driving may be applied to the first data line.

During the predetermined boosting time after the initialization period during the first sensing driving period, the voltage of the first reference voltage line may be increased from the first reference voltage.

When the boosting time elapses after the initialization period during the first sensing drive period, the sampling switch is turned on so that the first reference voltage line is electrically connected to the analog-to-digital converter, and the analog-to-digital converter is connected to the voltage of the first reference voltage line. A first sensed value may be output by sensing .

During an initialization period of a second sensing driving period different from the first sensing driving period, a second reference voltage different from the first reference voltage may be applied to the first reference voltage line. Also, during the initialization period of the second sensing drive period, the same data voltage for the second sensing drive as the data voltage for the first sensing drive may be applied to the first data line.

During the boosting time after the initialization period of the second sensing driving period, the voltage of the first reference voltage line may increase from the second reference voltage.

When the boosting time elapses after the initialization period during the second sensing driving period, the sampling switch is turned on so that the first reference voltage line is electrically connected to the analog-to-digital converter, and the analog-to-digital converter is connected to the voltage of the first reference voltage line. A second sensed value may be output by sensing .

Based on the first sensing value obtained during the first sensing driving period and the second sensing value obtained during the second sensing driving period, the gain and offset of the image driving data voltage supplied to the first subpixel may be changed.

The gain and offset of the image driving data voltage supplied to the first subpixel may vary according to the change in the mobility and threshold voltage of the driving transistor included in the first subpixel.

Each of the first sensing driving period and the second sensing driving period may be included in different blank periods.

In another aspect, embodiments of the present invention include a display panel on which a plurality of data lines and a plurality of gate lines are disposed, a plurality of reference voltage lines are disposed, and a plurality of subpixels are disposed; a data driving circuit for driving a plurality of data lines; and a gate driving circuit for driving the plurality of gate lines, wherein the plurality of subpixels include an organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first node of the driving transistor, and a corresponding one of the plurality of data lines. A first transistor electrically connected between data lines, a second transistor electrically connected between a second node of the driving transistor and a corresponding reference voltage line among a plurality of reference voltage lines, and between the first node and the second node of the driving transistor It is possible to provide a driving method of an organic light emitting display device including a capacitor electrically connected to .

The driving method includes a first sensing driving step of supplying a first reference voltage to a first reference voltage line electrically connected to a drain node or a source node of a second transistor included in a first arbitrary subpixel among a plurality of subpixels; , After the first sensing driving step, second sensing for supplying a second reference voltage different from the first reference voltage to a first reference voltage line electrically connected to the drain node or the source node of the second transistor included in the first subpixel. A driving step may be included.

A drain node or a source node of the first transistor included in the first subpixel may be electrically connected to a first data line among a plurality of data lines.

In the driving method, each of the first sensing driving step and the second sensing driving step includes an initialization step, a tracking step performed for a predetermined boosting time after the initialization step, and a sampling step performed when the boosting time elapses after the initialization step. can include

During the initialization phase of the first sensing driving phase, the first reference voltage may be supplied to the first reference voltage line, and the data voltage for the first sensing driving may be supplied to the first data line.

During the initialization phase of the second sensing-driving phase, a second reference voltage different from the first reference voltage is supplied to the first reference voltage line, and the second sensing-driving data voltage equal to the first sensing-driving data voltage is supplied to the first data line. voltage can be supplied.

During the tracking phase of the first sensing driving phase, the voltage of the first reference voltage line rises from the first reference voltage, and during the tracking phase of the second sensing driving phase, the voltage of the first reference voltage line rises from the second reference voltage. this can proceed.

During the sampling step of the first sensing driving step, the analog-to-digital converter may sense the voltage of the first reference voltage line and output a first sensed value. During the sampling step of the second sensing driving step, the analog-to-digital converter may sense the voltage of the first reference voltage line and output a second sensed value.

In the driving method, after the first sensing driving step and the second sensing driving step, the gain and offset of the image driving data voltage to be supplied to the first subpixel are changed based on the first sensed value and the second sensed value, and the first sensed value is changed. A compensation processing step of supplying data to the data line may be further included.

The gain and offset of the data voltage for driving the image may vary according to the change in the mobility and threshold voltage of the driving transistor included in the first subpixel.

The first sensing driving step may be performed in a first blank period, and the second sensing driving step may be performed in a second blank period different from the first blank period.

In another aspect, embodiments of the present invention include a display panel on which a plurality of data lines and a plurality of gate lines are disposed, a plurality of reference voltage lines are disposed, and a plurality of subpixels are disposed; a data driving circuit for driving a plurality of data lines; and a gate driving circuit for driving the plurality of gate lines, wherein the plurality of subpixels include an organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first node of the driving transistor, and a corresponding one of the plurality of data lines. A first transistor electrically connected between data lines, a second transistor electrically connected between a second node of the driving transistor and a corresponding reference voltage line among a plurality of reference voltage lines, and between the first node and the second node of the driving transistor A driving circuit of an organic light emitting display device including a capacitor electrically connected to may be provided.

The driving circuit includes: a data driving circuit supplying a data voltage for sensing driving to a first data line electrically connected to a drain node or a source node of a first transistor included in a first arbitrary subpixel among a plurality of subpixels; A reference voltage supply circuit for supplying a reference voltage to a first reference voltage line electrically connected to a drain node or a source node of a second transistor included in one subpixel may be included.

The reference voltage supply circuit may supply the first reference voltage to the first reference voltage line during the initialization period of the first sensing driving period.

The reference voltage supply circuit may supply a second reference voltage different from the first reference voltage to the first reference voltage line during an initialization period of a second sensing driving period different from the first sensing driving period.

The data driving circuit may supply the first sensing driving data voltage to the first data line during an initialization period of the first sensing driving period.

The data driving circuit may supply the same data voltage for the first sensing drive to the first data line during the initialization period of the second sensing drive period.

According to the embodiments of the present invention, there is an effect of providing a driving circuit, an organic light emitting display device, and a driving method that enable accurate sensing and compensation while reducing the time required for sensing.

In addition, according to embodiments of the present invention, there is an effect of providing a driving circuit capable of sensing the threshold voltage of a transistor in real time during image driving, an organic light emitting display device, and a driving method.

In addition, according to embodiments of the present invention, there is an effect of providing a driving circuit capable of simultaneously sensing the threshold voltage and mobility of a transistor in real time during image driving, an organic light emitting display device, and a driving method.

1 is a schematic system configuration diagram of an organic light emitting display device according to embodiments of the present invention.
2 is an exemplary system implementation diagram of an organic light emitting display device according to embodiments of the present invention.
3 is a circuit of a sub-pixel of an organic light emitting display device according to example embodiments of the present invention.
4 is a compensation circuit of an organic light emitting display device according to example embodiments.
5 is a driving timing diagram for sensing a threshold voltage of an organic light emitting display device according to embodiments of the present invention.
6 is a driving timing diagram for sensing mobility of an organic light emitting display device according to embodiments of the present invention.
7 is a diagram illustrating a sensing process that can be performed at various timings in an organic light emitting display device according to embodiments of the present invention.
8 is a layout view of four subpixels connectable to one sensing line and their peripheral wires in an organic light emitting display device according to embodiments of the present invention.
9 is an equivalent circuit of four subpixels connectable to one sensing line in an organic light emitting display device according to embodiments of the present invention.
10 is a conceptual diagram for explaining advanced real-time sensing of an organic light emitting display device according to embodiments of the present invention.
11 and 12 are driving timing diagrams for advanced real-time sensing of an organic light emitting display device according to embodiments of the present invention.
13 is a flowchart of a driving method for advanced real-time sensing of an organic light emitting display device according to embodiments of the present invention.
14 is a diagram illustrating a driving circuit for advanced real-time sensing of an organic light emitting display device according to embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention are described in detail below with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

Also, terms such as first, second, A, B, (a), and (b) may be used in describing the components of the present invention. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is or may be directly connected to that other element, but intervenes between each element. It will be understood that may be "interposed", or each component may be "connected", "coupled" or "connected" through other components.

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

Referring to FIG. 1 , an organic light emitting display device 100 according to the present embodiments includes a plurality of data lines DL and a plurality of gate lines GL, and a plurality of data lines DL and a plurality of gate lines GL. It may include a display panel 110 in which a plurality of subpixels SP defined by the gate line GL are arranged in a matrix type, and a driving circuit 111 for driving the display panel 110 .

From a functional point of view, the driving circuit 111 includes a data driving circuit 120 driving a plurality of data lines DL, a gate driving circuit 130 driving a plurality of gate lines GL, and a data driving circuit A controller 140 controlling the row 120 and the gate driving circuit 130 may be included.

In the display panel 110, the plurality of data lines DL and the plurality of gate lines GL may be disposed to cross each other. For example, the plurality of gate lines GL may be arranged in rows or columns, and the plurality of data lines DL may be arranged in columns or rows. Hereinafter, for convenience of description, it is assumed that the plurality of gate lines GL are arranged in rows and the plurality of data lines DL are arranged in columns.

In addition to the plurality of data lines DL and the plurality of gate lines GL, other types of wires may be disposed on the display panel 110 .

The controller 140 may supply image data DATA to the data driving circuit 120 .

In addition, the controller 140 supplies various control signals (DCS, GCS) necessary for driving the data driving circuit 120 and the gate driving circuit 130 to operate the data driving circuit 120 and the gate driving circuit 130. can control the operation of

The controller 140 starts scanning according to the timing implemented in each frame, converts the input image data input from the outside to suit the data signal format used in the data driving circuit 120, and converts the converted image data (DATA). and controls data drive at an appropriate time according to the scan.

In order to control the data driving circuit 120 and the gate driving circuit 130, the controller 140 includes a vertical sync signal (Vsync), a horizontal sync signal (Hsync), an input data enable (DE) signal, A timing signal such as the clock signal CLK is received from an external source (eg, a host system), and various control signals are generated and output to the data driving circuit 120 and the gate driving circuit 130 .

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

In addition, the controller 140, in order to control the data driving circuit 120, a source start pulse (SSP: Source Start Pulse), a source sampling clock (SSC: Source Sampling Clock), a source output enable signal (SOE: Source It outputs various data control signals (DCS: Data Control Signal) including Output Enable) and the like.

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

The controller 140 may be implemented as a component separate from the data driving circuit 120 or integrated with the data driving circuit 120 and implemented as an integrated circuit.

The data driving circuit 120 drives the plurality of data lines DL by receiving the image data DATA from the controller 140 and supplying data voltages to the plurality of data lines DL. Here, the data driving circuit 120 is also referred to as a source driving circuit.

The data driving circuit 120 may include a shift register, a latch circuit, a digital to analog converter (DAC), an output buffer, and the like.

In some cases, the data driving circuit 120 may further include one or more analog to digital converters (ADCs).

The gate driving circuit 130 sequentially drives the plurality of gate lines GL by sequentially supplying scan signals to the plurality of gate lines GL. Here, the gate driving circuit 130 is also referred to as a scan driving circuit.

The gate driving circuit 130 may include a shift register, a level shifter, and the like.

The gate driving circuit 130 sequentially supplies scan signals of an on voltage or an off voltage to the plurality of gate lines GL under the control of the controller 140 .

When a specific gate line is opened by the gate driving circuit 130, the data driving circuit 120 converts the image data DATA received from the controller 140 into an analog data voltage to generate a plurality of data lines DL. supplied with

The data driving circuit 120 may be located on only one side (eg, upper or lower side) of the display panel 110, and in some cases, both sides of the display panel 110 ( eg on the upper side and the lower side).

The gate driving circuit 130 may be located on only one side (eg, the left or right side) of the display panel 110, and in some cases, both sides of the display panel 110 ( Example: left and right) may be located on both sides.

The data driving circuit 120 may be implemented by including at least one Source Driver Integrated Circuit (SDIC).

Each source driver integrated circuit (SDIC) is connected to a bonding pad of the display panel 110 or directly disposed on the display panel 110 using a Tape Automated Bonding (TAB) method or a Chip On Glass (COG) method. It could be. In some cases, each source driver integrated circuit (SDIC) may be integrated and disposed on the display panel 110 . In addition, each source driver integrated circuit (SDIC) may be implemented in a COF (Chip On Film) method. In this case, each source driver integrated circuit SDIC may be mounted on a circuit film and electrically connected to the data lines DL of the display panel 110 through the circuit film.

In the gate driving circuit 130 , one or more gate driver integrated circuits (GDICs) may be connected to bonding pads of the display panel 110 using a TAB method or a COG method. In addition, the gate driving circuit 130 may be implemented as a GIP (Gate In Panel) type and directly disposed on the display panel 110 . In addition, the gate driving circuit 130 may be implemented in a COF (Chip On Film) method. In this case, each gate driver integrated circuit (GDIC) included in the gate driving circuit 130 may be mounted on a circuit film and electrically connected to the gate lines GL of the display panel 110 through the circuit film. there is..

2 is an exemplary system implementation diagram of an organic light emitting display device 100 according to embodiments of the present invention.

In the example of FIG. 2, each source driver integrated circuit (SDIC) included in the data driving circuit 120 is implemented in a COF (Chip On Film) method among various methods (TAB, COG, COF, etc.), and the gate driving circuit (130) is implemented as a GIP (Gate In Panel) type among various methods (TAB, COG, COF, GIP, etc.).

Each of the plurality of source driver integrated circuits (SDICs) included in the data driving circuit 120 may be mounted on the source-side circuit film (SF).

One side of the source-side circuit film SF may be electrically connected to the display panel 110 .

Wires for electrically connecting the source driver integrated circuit SDIC and the display panel 110 may be disposed on the source-side circuit film SF.

The organic light emitting display device 100 mounts at least one source printed circuit board (SPCB), control parts, and various electrical devices for circuit connection between a plurality of source driver integrated circuits (SDICs) and other devices. It may include a control printed circuit board (CPCB) for

The other side of the source-side circuit film SF on which the source driver integrated circuit SDIC is mounted may be connected to at least one source printed circuit board SPCB.

That is, one side of the source-side circuit film SF on which the source driver integrated circuit (SDIC) is mounted may be electrically connected to the display panel 110 and the other side may be electrically connected to the source printed circuit board (SPCB). .

In the control printed circuit board (CPCB), the controller 140 for controlling operations of the data driving circuit 120 and the gate driving circuit 130, the display panel 110, the data driving circuit 120, and the gate driving circuit A power management integrated circuit (PMIC) 210 or the like that supplies various voltages or currents to 130 or the like or controls various voltages or currents to be supplied may be mounted.

The at least one source printed circuit board (SPCB) and the control printed circuit board (CPCB) may be circuitically connected through at least one connecting member. Here, the connecting member may be, for example, a flexible printed circuit (FPC) or a flexible flat cable (FFC).

At least one source printed circuit board (SPCB) and one control printed circuit board (CPCB) may be integrated into one printed circuit board.

The organic light emitting display device 100 may further include a set board 230 electrically connected to the control printed circuit board (CPCB). This set board 230 may also be referred to as a power board.

The set board 230 may include a main power management circuit 220 (M-PMC: Main Power Management Circuit) that manages overall power of the organic light emitting display device 100 .

The power management integrated circuit 210 is a circuit that manages power for the display module including the display panel 110 and its driving circuits 120, 130, 140, etc., and the main power management circuit 220 controls the display module. It is a circuit that manages overall power, including power management, and can work with the power management integrated circuit 210 .

Each subpixel (SP) arranged on the display panel 110 included in the organic light emitting display device 100 according to the present embodiments includes an organic light emitting diode (OLED), which is a self-light emitting device, and an organic light emitting diode (OLED). It may be composed of circuit elements such as a driving transistor for driving the diode OLED.

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

3 is a circuit of each sub-pixel SP of the organic light emitting display device 100 according to example embodiments.

The display panel 110 according to the exemplary embodiments includes a plurality of data lines DL, a plurality of gate lines GL, a plurality of driving voltage lines DVL, and a plurality of reference voltage lines RVL. can be placed.

Each subpixel SP in the display panel 110 includes an organic light emitting diode (OLED), a driving transistor (DRT) for driving the organic light emitting diode (OLED), and a first node (N1) of the driving transistor (DRT). ) and the corresponding data line DL, the corresponding reference voltage line RVL among the second node N2 of the driving transistor DRT and the plurality of reference voltage lines RVL. It may be implemented by including a second transistor T2 electrically connected therebetween, a storage capacitor Cst electrically connected between the first node N1 and the second node N2 of the driving transistor DRT, and the like. .

An organic light emitting diode (OLED) may include an anode electrode, an organic light emitting layer, and a cathode electrode.

According to the circuit example of FIG. 3 , the anode electrode of the organic light emitting diode OLED may be electrically connected to the second node N2 of the driving transistor DRT. The ground voltage EVSS may be applied to the cathode electrode of the organic light emitting diode OLED.

Here, the base voltage EVSS may be, for example, a ground voltage or a voltage higher or lower than the ground voltage. Also, the electromotive voltage EVSS may vary according to the driving state. For example, the base voltage EVSS during image driving and the base voltage EVSS during sensing driving may be set differently.

The driving transistor DRT drives the organic light emitting diode (OLED) by supplying a driving current to the organic light emitting diode (OLED).

The driving transistor DRT may include a first node N1 , a second node N2 , and a third node N3 .

The first node N1 of the driving transistor DRT may be a gate node and may be electrically connected to a source node or a drain node of the first transistor T1. The second node N2 of the driving transistor DRT may be a source node or a drain node, may be electrically connected to an anode electrode (or a cathode electrode) of the organic light emitting diode OLED, and may be the second node of the second transistor T2. It may also be electrically connected to a source node or a drain node. The third node N3 of the driving transistor DRT may be a drain node or a source node, to which the driving voltage EVDD may be applied, and a driving voltage line DVL supplying the driving voltage EVDD. ) and electrically connected. Hereinafter, for convenience of description, in the driving transistor DRT, the first node N1 is a gate node, the second node N2 is a source node, and the third node N3 is a drain node. can be heard and explained.

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

The drain node or source node of the first transistor T1 is electrically connected to the corresponding data line DL, and the source node or drain node of the first transistor T1 is connected to the first node N1 of the driving transistor DRT. and the gate node of the first transistor T1 is electrically connected to the corresponding gate line to receive the scan signal SCAN.

The first transistor T1 may be turned on and off by being applied to a gate node of the scan signal SCAN through a corresponding gate line.

The first transistor T1 may be turned on by the scan signal SCAN to transfer the data voltage Vdata supplied from the corresponding data line DL to the first node N1 of the driving transistor DRT. there is.

The drain node or source node of the second transistor T2 is electrically connected to the reference voltage line RVL, and the source node or drain node of the second transistor T2 is connected to the second node N2 of the driving transistor DRT. can be electrically connected to A gate node of the second transistor T2 may be electrically connected to a corresponding gate line to receive the sense signal SENSE.

The on/off of the second transistor T2 may be controlled by receiving the sense signal SENSE to a gate node through a corresponding gate line.

The second transistor T2 may be turned on by the sense signal SENSE and transfer the reference voltage Vref supplied from the corresponding reference voltage line RVL to the second node N2 of the driving transistor DRT. there is.

Meanwhile, the storage capacitor Cst is not a parasitic capacitor (eg, Cgs or Cgd) that is an internal capacitor existing between the first node N1 and the second node N2 of the driving transistor DRT. , may be an external capacitor intentionally designed outside the driving transistor DRT.

Each of the driving transistor DRT, the first transistor T1 and the second transistor T2 may be an n-type transistor or a p-type transistor.

Meanwhile, the scan signal SCAN and the sense signal SENSE may be separate gate signals. In this case, the scan signal SCAN and the sense signal SENSE may be respectively applied to the gate node of the first transistor T1 and the gate node of the second transistor T2 through different gate lines.

In some cases, the scan signal SCAN and the sense signal SENSE may be the same gate signal. In this case, the scan signal SCAN and the sense signal SENSE may be commonly applied to the gate node of the first transistor T1 and the gate node of the second transistor T2 through the same gate line.

Each sub-pixel structure illustrated in FIG. 3 is a 3T (transistor) 1C (capacitor) structure, which is only an example for description, and may further include one or more transistors or, in some cases, one or more capacitors. may be Alternatively, each of a plurality of subpixels may have the same structure, and some of the plurality of subpixels may have a different structure.

Below, an image driving operation of each sub-pixel (SP) will be briefly described as an example.

The display driving (also referred to as image driving) operation of each sub-pixel (SP) may proceed to an image data recording step, a boosting step, and a light emission step.

In the image data writing step, the image driving data voltage Vdata corresponding to the image signal is applied to the first node N1 of the driving transistor DRT, and the image data voltage Vdata is applied to the second node N2 of the driving transistor DRT. A driving reference voltage Vref may be applied. Here, a voltage similar to the reference voltage Vref is applied to the second node N2 of the driving transistor DRT due to a resistance component between the second node N2 of the driving transistor DRT and the reference voltage line RVL. (Vref') may be applied.

The reference voltage Vref for image driving is also referred to as VpreR.

In the image data writing step, the first transistor T1 and the second transistor T2 may be turned on simultaneously or with a slight time difference.

In the image data recording step, the storage capacitor Cst may be charged with an electric charge corresponding to a potential difference between both ends (Vdata-Vref or Vdata-Vref').

Applying the image driving data voltage Vdata to the first node N1 of the driving transistor DRT is referred to as image data writing.

In the boosting step following the image data writing step, the first node N1 and the second node N2 of the driving transistor DRT may be electrically floated simultaneously or with a slight time difference.

To this end, the first transistor T1 may be turned off by the turn-off level voltage of the scan signal SCAN. Also, the second transistor T2 may be turned off by the turn-off level voltage of the sense signal SENSE.

In the boosting step, while the voltage difference between the first node N1 and the second node N2 of the driving transistor DRT is maintained, the first node N1 and the second node N2 of the driving transistor DRT are respectively The voltage of may be boosted.

During the boosting step, the voltage of each of the first node N1 and the second node N2 of the driving transistor DRT is boosted, and then the increased voltage of the second node N2 of the driving transistor DRT is When a certain voltage (that is, a voltage capable of turning on the organic light emitting diode (OLED), which is higher than the threshold voltage of the organic light emitting diode (OLED) from the base voltage (EVSS)) is reached, the light emitting stage is entered.

In this light emitting step, a driving current flows into the organic light emitting diode (OLED). Accordingly, the organic light emitting diode (OLED) may emit light.

The driving transistor DRT disposed in each of the plurality of sub-pixels SP arranged on the display panel 110 according to embodiments of the present invention has unique characteristics such as threshold voltage and mobility (also referred to as electron mobility). have

The driving transistor DRT may be deteriorated according to driving time. Accordingly, the unique characteristics of the driving transistor DRT may change according to driving time.

The on-off timing of the driving transistor DRT may vary or the driving capability of the organic light emitting diode OLED may vary according to a change in characteristic value. That is, the timing at which current is supplied to the organic light emitting diode (OLED) and the amount of current supplied to the organic light emitting diode (OLED) may be changed according to a change in characteristic values of the driving transistor DRT. According to the change in the characteristic value of the driving transistor DRT, the actual luminance of the corresponding subpixel SP may be different from the desired luminance.

Also, the plurality of subpixels SP arranged on the display panel 110 may have different driving times. Therefore, characteristic value deviations (threshold voltage deviations and mobility deviations) between the driving transistors DRT in each subpixel SP may occur.

The characteristic value deviation between the driving transistors DRT may cause a luminance deviation between the subpixels SP. Accordingly, luminance uniformity of the display panel 110 may be deteriorated, which may eventually lead to image quality deterioration.

Accordingly, the organic light emitting display device 100 according to embodiments of the present invention may include a compensation circuit capable of compensating for a characteristic value deviation between driving transistors DRT, and may provide a compensation method using the compensation circuit. This will be described in more detail with reference to FIGS. 4 to 7 .

4 is an exemplary compensation circuit of the organic light emitting display device 100 according to embodiments of the present invention.

The organic light emitting display device 100 according to embodiments of the present invention needs to sense a characteristic value or change in characteristic value of each driving transistor DRT in order to compensate for a characteristic value deviation between the driving transistors DRT.

The compensation circuit of the organic light emitting display device 100 according to the embodiments of the present invention drives (sensing drive) a subpixel SP having a 3T1C structure or a modified structure based on the 3T1C structure to drive within the subpixel SP. A sensing circuit 410 for sensing a characteristic value or change in characteristic value of the transistor DRT may be included.

In this specification, for convenience of description, “sensing a characteristic value or a characteristic value change of the driving transistor DRT in the subpixel SP” is also referred to as “sensing the subpixel SP”. In addition, “compensating for the characteristic value or change in characteristic value of the driving transistor DRT in the sub-pixel SP” is also referred to as “compensating for the sub-pixel SP”.

The organic light emitting display device 100 according to embodiments of the present invention senses the voltage of the reference voltage line RVL through sensing driving, and uses the sensed voltage to control the driving transistor DRT in the subpixel SP. A characteristic value or characteristic value change can be detected. Here, the reference voltage line (RVL) serves not only to deliver the reference voltage (Vref), but also to sense the characteristics of the subpixel (eg, the characteristic value of the driving transistor (DRT)). It can serve as a sensing line for

More specifically, according to the sensing operation of the organic light emitting display device 100 according to the embodiments of the present invention, the characteristic value or change in characteristic value of the driving transistor DRT is the voltage of the second node N2 of the driving transistor DRT. (e.g. Vdata-Vth).

The voltage of the second node N2 of the driving transistor DRT may correspond to the voltage of the reference voltage line RVL when the second transistor T2 is in a turn-on state. The line capacitor Cline on the reference voltage line RVL may be charged by the voltage of the second node N2 of the driving transistor DRT. The reference voltage line RVL may have a voltage corresponding to the voltage of the second node N2 of the driving transistor DRT by the charged line capacitor Cline.

The compensation circuit of the organic light emitting display device 100 according to embodiments of the present invention includes on-off control of each of a first transistor T1 and a second transistor T2 in a subpixel SP to be sensed, and , the second node N2 of the driving transistor DRT controls the characteristic values (threshold voltage, mobility) or changes in characteristic values of the driving transistor DRT through control of supply of the data voltage Vdata and the reference voltage Vref, respectively. It can be driven so as to reflect the voltage state.

Referring to FIG. 4 , the organic light emitting display device 100 according to example embodiments may include a sensing circuit 410 for sensing a plurality of reference voltage lines RVL.

The sensing circuit 410 senses the voltage of the reference voltage line RVL corresponding to the voltage of the second node N2 of the driving transistor DRT, and converts the sensed voltage into a sensed value corresponding to a digital value. It may include an analog-to-digital converter (ADC) and a switch circuit (SAM, SPRE) for sensing driving.

The sensing circuit 410 may exist outside the data driving circuit 120 (eg, a PCB) or may be included inside the data driving circuit 120 .

The switch circuits SAM and SPRE for sensing driving may control the voltage state of the corresponding reference voltage line RVL or control whether or not the reference voltage line RVL is connected to the analog-to-digital converter ADC.

The switch circuits SAM and SPRE for sensing driving include a reference switch for sensing driving that controls the connection between each reference voltage line RVL and a reference voltage supply node Npres for sensing driving to which the reference voltage Vref is supplied. SPRE) and a sampling switch (SAM) that controls the connection between each reference voltage line (RVL) and the analog-to-digital converter (ADC).

The aforementioned reference switch SPRE for sensing driving is a switch used for sensing driving. The reference voltage Vref supplied to the reference voltage line RVL by the reference switch SPRE for sensing drive is “reference voltage VpreS for sensing drive”.

Meanwhile, referring to FIG. 4 , the switch circuit may include an image driving reference switch RPRE used when driving an image.

The image driving reference switch RPRE may control the connection between each reference voltage line RVL and the image driving reference voltage supply node Nprer to which the reference voltage Vref is supplied.

The image driving reference switch RPRE mentioned above is a switch used when driving an image. The reference voltage Vref supplied to the reference voltage line RVL by the image driving reference switch SPRE is the "image driving reference voltage VpreR".

The reference switch for sensing driving (SPRE) and the reference switch for image driving (RPRE) may be provided separately or may be integrated into one. The reference voltage VpreS for sensing driving and the reference voltage VpreR for image driving may have the same voltage value or different voltage values.

The compensation circuit of the organic light emitting display device 100 according to embodiments of the present invention includes a memory MEM that stores a sensing value output from an analog-to-digital converter (ADC) or previously stores a reference sensing value, and a memory ( A compensator (COMP) that compares the sensing value stored in the MEM with a reference sensing value to calculate a compensation value for compensating for a characteristic value deviation may be further included.

The compensation value calculated by the compensator COMP may be stored in the memory MEM.

The controller 140 changes the image data Data to be supplied to the data driving circuit 120 using the compensation value calculated by the compensator COM, and outputs the changed image data Data_comp to the data driving circuit 120. can do.

Accordingly, the data driving circuit 120 converts the image data (Data_comp) changed through the digital-to-analog converter (DAC) into a data voltage (Vdata_comp) in the form of an analog signal, and converts the converted data voltage (Vdata_comp) into an output buffer ( BUF) to the corresponding data line DL. Accordingly, characteristic value deviations (threshold voltage deviation and mobility deviation) of the driving transistor DRT of the corresponding subpixel SP may be compensated for.

Meanwhile, referring to FIG. 4 , the data driving circuit 120 may include a data voltage output circuit 400 including a latch circuit, a digital-to-analog converter (DAC), and an output buffer (BUF). Accordingly, an analog-to-digital converter (ADC) and various switches (SAM, SPRE, RPRE) may be further included.

Alternatively, the analog-to-digital converter (ADC) and various switches (SAM, SPRE, and RPRE) may be located outside the data driving circuit 120, not inside the data driving circuit 120.

Referring to FIG. 4 , the compensator COMP may exist outside the controller 140 or may be included inside the controller 140 . Also, the memory MEM may be located outside the controller 140 or implemented in the form of a register inside the controller 140 .

5 is a driving timing diagram for sensing a threshold voltage of the organic light emitting display device 100 according to embodiments of the present invention.

Referring to FIG. 5 , threshold voltage sensing driving may proceed to an initialization step ( S510 ), a tracking step ( S520 ), and a sampling step ( S530 ).

In the initialization step S510, the first transistor T1 is turned on by the scan signal SCAN of the turn-on level voltage. Accordingly, the first node N1 of the driving transistor DRT is initialized with the data voltage Vdata for driving the threshold voltage sensing.

In the initialization step S510, the second transistor T2 is turned on and the sensing drive reference switch SPRE is turned on by the sense signal SENSE of the turn-on level voltage. Accordingly, the second node N2 of the driving transistor DRT is initialized to the reference voltage VpreS for sensing driving.

The tracking step ( S520 ) is a step of tracking the threshold voltage (Vth) of the driving transistor (DRT). That is, in the tracking step S520, the voltage of the second node N2 of the driving transistor DRT reflecting the threshold voltage Vth of the driving transistor DRT is tracked.

In the tracking step ( S520 ), the first transistor T1 and the second transistor T2 maintain a turned-on state, and the sensing drive reference switch SPRE is turned off. Accordingly, the second node N2 of the driving transistor DRT floats, and the voltage of the second node N2 of the driving transistor DRT starts to rise from the sensing driving reference voltage VpreS.

Since the second transistor T2 is turned on, an increase in the voltage of the second node N2 of the driving transistor DRT leads to an increase in the voltage of the reference voltage line RVL.

The voltage of the second node N2 of the driving transistor DRT rises and then becomes saturated. The saturated voltage of the second node N2 of the driving transistor DRT corresponds to the voltage difference (Vdata−Vth) between the threshold voltage Vth of the driving transistor DRT in the data voltage Vdata for driving the threshold voltage sensing. do.

Therefore, when the voltage of the second node N2 of the driving transistor DRT is saturated, the voltage Vrvl of the reference voltage line RVL changes from the threshold voltage sensing driving data voltage Vdata to the voltage of the driving transistor DRT. It corresponds to the voltage difference (Vdata-Vth) of the threshold voltage.

When the voltage of the second node N2 of the driving transistor DRT reaches saturation, the sampling switch SAM is turned on, and a sampling step ( S530 ) proceeds.

In the sampling step (S530), the analog-to-digital converter (ADC) senses the voltage (Vrvl) of the reference voltage line (RVL) connected by the sampling switch (SAM) as the sensing voltage (Vsen), and the sensing voltage (Vsen) It can be converted into a sensing value corresponding to a digital value. Here, the voltage Vsen sensed by the analog-to-digital converter (ADC) corresponds to “Vdata-Vth”.

The compensator (COMP) can determine the threshold voltage of the driving transistor (DRT) of the corresponding sub-pixel (SP) based on the sensing value output from the analog-to-digital converter (ADC), and determine the threshold voltage of the driving transistor (DRT) can compensate

The compensator (COMP) determines the value of the driving transistor (DRT) from the sensing value (digital value corresponding to Vdata-Vth) measured through sensing driving and the known threshold voltage sensing and driving data (digital value corresponding to Vdata). The threshold voltage (Vth) can be identified.

The compensator COMP compares the identified threshold voltage Vth of the corresponding driving transistor DRT with a reference threshold voltage or a threshold voltage of another driving transistor DRT to compensate for the threshold voltage deviation between the driving transistors DRT. can do it Here, the threshold voltage deviation compensation may mean image data change processing (processing of adding or subtracting a compensation value (offset) to image data).

6 is a driving timing diagram for sensing mobility of the organic light emitting display device 100 according to embodiments of the present invention.

Referring to FIG. 6 , mobility sensing driving may proceed to an initialization step ( S610 ), a tracking step ( S620 ), and a sampling step ( S630 ).

In the initialization step S610, the first transistor T1 is turned on by the scan signal SCAN of the turn-on level voltage. Accordingly, the first node N1 of the driving transistor DRT is initialized with the data voltage Vdata for driving the mobility sensing.

In the initialization step S610, the second transistor T2 is turned on and the sensing drive reference switch SPRE is turned on by the sense signal SENSE of the turn-on level voltage. Accordingly, the second node N2 of the driving transistor DRT is initialized to the reference voltage VpreS for sensing driving.

The tracking step ( S620 ) is a step of tracking the mobility of the driving transistor DRT. Mobility of the driving transistor DRT may indicate current driving capability of the driving transistor DRT. That is, in the tracking step ( S520 ), the voltage of the second node N2 of the driving transistor DRT from which the mobility of the driving transistor DRT can be calculated is tracked.

In the tracking step S620, the first transistor T1 is turned off by the scan signal SCAN of the turn-off level voltage, and the sensing driving reference switch SPRE is turned off. Accordingly, both the first node N1 and the second node N2 of the driving transistor DRT are floated. Accordingly, the voltages of the first node N1 and the second node N2 of the driving transistor DRT both rise. In particular, the voltage of the second node N2 of the driving transistor DRT starts to rise from the sensing driving reference voltage VpreS.

Since the second transistor T2 is turned on, an increase in the voltage of the second node N2 of the driving transistor DRT leads to an increase in the voltage of the reference voltage line RVL.

When a predetermined time Δt elapses from the point at which the voltage of the second node N2 of the driving transistor DRT starts to rise, the sampling switch SAM is turned on and the sampling step S630 proceeds. do.

In the sampling step (S630), the analog-to-digital converter (ADC) senses the voltage (Vrvl) of the reference voltage line (RVL) connected by the sampling switch (SAM) as the sensing voltage (Vsen), and the sensing voltage (Vsen) It can be converted into a sensing value corresponding to a digital value. Here, the voltage Vsen sensed by the analog-to-digital converter ADC corresponds to a voltage (VpreS+ΔV) increased by a predetermined voltage ΔV from the sensing driving reference voltage VpreS. Here, the predetermined time (Δt) is a predetermined time, and may also be described as a boosting time below.

The compensator COMP may determine the mobility of the driving transistor DRT of the corresponding subpixel SP based on the sensing value output from the analog-to-digital converter ADC, and determine the mobility of the driving transistor DRT. can compensate

The compensator COMP determines the value of the driving transistor DRT from the sensing value (digital value corresponding to VpreS+ΔV) measured through sensing driving, the already known reference voltage for sensing driving (VpreS) and the elapsed time (Δt). mobility can be identified.

The mobility of the driving transistor DRT is proportional to the amount of voltage variation (ΔV/Δt) per unit time of the reference voltage line RVL in the tracking step S620. That is, the mobility of the driving transistor DRT is proportional to the slope (Slope, SLP) of the voltage waveform of the reference voltage line RVL in FIG. 6 .

The compensator COMP may compensate for a mobility deviation between driving transistors DRT by comparing the mobility of the corresponding driving transistor DRT with a reference mobility or mobility of other driving transistors DRT. Here, the mobility deviation compensation may mean image data change processing (an operation processing of multiplying image data by a compensation value (gain)).

7 is a diagram illustrating a sensing process that can be performed at various timings in the organic light emitting display device 100 according to embodiments of the present invention.

Referring to FIG. 7 , when a power-on signal is generated, the organic light-emitting display device 100 performs a predetermined on-sequence process for starting display driving, and when the on-sequence process is completed, normal display driving begins.

When a power off signal is generated, the organic light emitting display device 100 stops display driving in progress and performs a predetermined off sequence process. When the off sequence process is completed, the organic light emitting display device 100 enters a completely off state.

In relation to the power processing timing, sensing driving (threshold voltage sensing driving and mobility sensing driving) may be performed.

Sensing driving may be performed after the power-on signal is generated and before display driving starts. Such sensing and sensing processes are referred to as on-sensing and on-sensing processes.

Also, sensing driving may be performed after the power off signal is generated. Such sensing and sensing processes are referred to as off-sensing and off-sensing processes.

Also, sensing driving may be performed in real time during display driving. Such a sensing processor is referred to as a real-time (RT) sensing process.

In the case of the RT sensing process, sensing driving may be performed for one or more subpixels SP in one or more subpixel lines (subpixel rows) for each blank time during display driving.

When sensing driving (RT sensing driving) is performed in the blank time, a subpixel line (subpixel row) on which sensing driving is performed may be randomly selected. Accordingly, an abnormal image phenomenon in a sub-pixel line subjected to sensing driving in an active time after sensing driving in a blank time may be alleviated. In addition, after the sensing drive in the blank time, the recovery data voltage corresponding to the data voltage before the sensing drive may be supplied to the subpixel that has been sensing driven in the active time. Accordingly, an abnormal image phenomenon in a sub-pixel line subjected to sensing driving in an active time after sensing driving in a blank time may be further alleviated.

Meanwhile, since the mobility sensing drive requires a relatively short time compared to the threshold voltage sensing drive, it may be performed by any process among short-time on-sensing processes and RT sensing processes.

For example, mobility sensing driving may be performed as an on-sensing process to obtain a reference sensing value after a power-on signal is generated, and may also be performed as an RT sensing process using blank periods during image driving.

However, in the case of threshold voltage sensing driving, since it may take a long time for the voltage of the second node N2 of the driving transistor DRT to saturate, an off-sensing process may be performed for a rather long time. can

In particular, when the number of subpixels increases according to the high resolution, it may take a very long time to sense the threshold voltage of the driving transistor DRT in all the subpixels SP disposed on the display panel 110. Voltage sensing driving may be performed as an RT sensing process during image driving.

Also, when the mobility sensing drive is performed after the threshold voltage sensing drive is performed, the sensing drive data voltage Vdata_sen for the mobility sensing drive may be a data voltage to which a threshold voltage compensation value is applied. That is, the sensing driving data voltage Vdata_sen for mobility sensing driving may be a data voltage offset by a voltage corresponding to the threshold voltage compensation value.

Meanwhile, before shipment of the product, reference values of the threshold voltage sensing value and reference values of the mobility sensing value are obtained in advance and stored in the memory MEM.

Meanwhile, in one subpixel SP having the structure shown in FIG. 3, one data voltage Vdata, two gate signals SCAN and SENSE, a reference voltage Vref, a driving voltage EVDD, and the like are applied. must be supplied Therefore, one subpixel (SP) should be electrically connected to one data line (DL), one or two gate lines (GL), one reference voltage (SL), and one driving voltage line (DVL). (see Figure 3).

In order to turn on or off one subpixel row, one or two gate lines GL must be disposed for each subpixel row. However, below, for convenience of description, it is assumed that two gate lines GL are disposed in one subpixel row. According to this assumption, the scan signal SCAN and the sense signal SENSE may be respectively transferred through the two gate lines GL.

In addition, since the data voltage Vdata must be supplied to each subpixel SP, one data line DL can be disposed for each subpixel column. In some cases, one data line DL may be commonly arranged for every two subpixel columns.

Since the driving voltage EVDD may be a common voltage, one driving voltage line DVL may be disposed for each subpixel column (or one subpixel row), or two or more subpixel columns (or two subpixel rows). One driving voltage line (DVL) may be arranged for every subpixel column).

Similarly, since the reference voltage Vref may be a common voltage, one reference voltage line RVL may be disposed for each subpixel column (or one subpixel row), and two or more subpixel columns ( Alternatively, one reference voltage line RVL may be disposed for every two or more subpixel columns).

When one driving voltage line (DVL) and/or one reference voltage line (RVL) is disposed for every two or more subpixel columns (or two or more subpixel columns), the aperture ratio of the display panel 110 is further increased. can give

For example, when the display panel 100 is composed of subpixels emitting four colors (red, green, blue, and white), one reference voltage line RVL is disposed for every four subpixel columns. can In this case, all subpixels included in the four subpixel columns may receive the reference voltage Vref from one reference voltage line RVL or be sensed through one reference voltage line RVL.

Below, in order to increase the aperture ratio of the display panel 110, one driving voltage line DVL is disposed parallel to the data line DL for every four or more subpixel columns, and one driving voltage line DVL is disposed in parallel with the data line DL for every four or more subpixel columns. A structure in which the two reference voltage lines RVL are arranged in parallel with the data line DL will be described with reference to FIG. 8 .

8 illustrates four sub-pixels SP1 to SP4 connectable to one first reference voltage line RVL1 and their peripheral wires DL1 to SP4 in the organic light emitting display device 100 according to embodiments of the present invention. DL4, DVL1, DVL2, SL1, GL1, GL2), and FIG. 9 is an equivalent circuit obtained by applying the subpixel structure of FIG. 3 and the sensing circuit 410 to the layout structure of FIG.

One subpixel row may include many subpixels, among which four subpixels SP1 to SP4 are electrically connected to the first reference voltage line RVL1 as shown in FIGS. 8 and 9 . this is possible

Each of the four subpixels SP1 to SP4 may mean a subpixel representing four subpixel columns. That is, the first subpixel SP1 represents the first subpixel column, the second subpixel SP2 represents the second subpixel column, and the third subpixel SP3 represents the third subpixel column. , and the fourth subpixel SP4 may represent the fourth subpixel row. Accordingly, the arrangement structure of FIGS. 8 and 9 may be extended and applied to the display panel 110 .

According to the example of FIG. 8 , a scan signal SCAN applied to the gate node of the first transistor T1 included in each of the four subpixels SP1 to SP4 and a scan signal applied to the gate node of the second transistor T2 It is assumed that the sense signals SENSE are separate gate signals.

Therefore, the gate line GL1 for transmitting the scan signal SCAN to each of the four subpixels SP1 to SP4 included in one subpixel row and the sense signal to each of the four subpixels SP1 to SP4 A gate line GL2 for transmitting (SENSE) may be disposed.

Four data lines DL1 to DL4 may be disposed on the display panel 110 to supply the data voltage Vdata to each of the four subpixels SP1 to SP4.

The first data line DL1 and the second data line DL2 may be positioned between the first subpixel SP1 and the second subpixel SP2. The third data line DL3 and the fourth data line DL4 may be positioned between the third subpixel SP3 and the fourth subpixel SP4.

In order to increase the aperture ratio of the display panel 110, the driving voltage lines DVL1 and DVL2 delivering the driving voltage EVDD that can be the common voltage and the first driving voltage lines DVL1 and DVL2 delivering the reference voltage Vref that can be the common voltage. The reference voltage line RVL1 may be arranged in a shared structure.

That is, the driving voltage lines DVL1 and DVL2 may not be arranged one by one in each subpixel column, but one in each of a plurality of subpixel columns. The first reference voltage line RVL1 may not be disposed one by one in each subpixel column, but one in each of a plurality of subpixel columns.

More specifically, the first subpixel SP1 and the second subpixel SP2 may receive the driving voltage EVDD in common through the first driving voltage line DVL1. The third subpixel SP3 and the fourth subpixel SP4 may receive the driving voltage EVDD in common through the second driving voltage line DVL2 .

The source node or drain node of the second transistor T1 included in each of the first subpixel SP1 , the second subpixel SP2 , the third subpixel SP3 , and the fourth subpixel SP4 is a source node or a drain node of the first subpixel SP4 . It may be commonly connected to the reference voltage line RVL1.

Accordingly, the first to fourth subpixels SP1 to SP4 may be commonly supplied with the reference voltage Vref through one first reference voltage line RVL1.

Meanwhile, referring to FIGS. 8 and 9 , for example, one first reference voltage line RVL1 may be disposed between the second subpixel SP2 and the third subpixel SP3. In this case, the first subpixel SP1 and the fourth subpixel SP4 may be connected to one first reference voltage line RVL1 through the connection line CL. The connection line CL may be integral with the first reference voltage line RVL1, or it may be located on a different layer from the first reference voltage line RVL1 and make contact therewith.

Meanwhile, the data lines DL1 to DL4 may be symmetrically disposed with respect to one first reference voltage line RVL1. The driving voltage lines DVL1 and DVL2 may be symmetrically disposed with respect to one first reference voltage line RVL1.

Referring to FIGS. 8 and 9 , the sensing circuit 410 may be connected to one first reference voltage line RVL1. Accordingly, at one point in time, only one subpixel among the four subpixels SP1 to SP4 may be sensed.

Below, as shown in FIGS. 8 and 9 , when one first reference voltage line RVL1 is shared by four subpixels SP1 to SP4, sensing and compensation will be described. However, below, mobility sensing performed with the same timing diagram as shown in FIG. 6 will be described as an example.

As described above, in the case of threshold voltage sensing driving, since it may take a long time for the voltage of the second node N2 of the driving transistor DRT to saturate, off-sensing can be performed for a rather long time. process can proceed. In particular, when the number of subpixels increases according to the high resolution, it may take a very long time to sense the threshold voltage of the driving transistor DRT in all the subpixels SP disposed on the display panel 110. Voltage sensing driving may be performed as an RT sensing process during image driving.

Therefore, there is a disadvantage in that the threshold voltage sensing driving process of obtaining the reference value of the threshold voltage sensing value takes too long before product shipment. In addition, if the threshold voltage sensing drive only proceeds through an off-sensing process after product shipment, a change in threshold voltage during image driving cannot be immediately reflected, resulting in a deterioration in image quality. In particular, there is a possibility that a large threshold voltage change occurs during image driving for a long time. In this case, the threshold voltage sensing driving performed in an off-sensing process cannot compensate for the immediate threshold voltage change.

In addition, if the user cuts off the power itself or turns the power back on while the threshold voltage sensing drive is in progress as an off-sensing process, the threshold voltage sensing drive is not normally completed and thus the threshold voltage change cannot be compensated for.

Accordingly, embodiments of the present invention may provide a driving method capable of sensing a threshold voltage even during image driving. In addition, embodiments of the present invention may provide a driving method capable of sensing both mobility and threshold voltage during image driving. Below, this driving method will be described in detail.

10 is a conceptual diagram for explaining Advanced Real-Time Sensing (ARTS) of the organic light emitting display device 100 according to embodiments of the present invention.

Below, an arbitrary first subpixel SP1 among a plurality of subpixels SP is taken as an example. In the first subpixel SP1, the first reference voltage line RVL1 and the first data line DL1 are electrically connected.

Referring to FIG. 10 , according to the advanced real-time sensing (ARTS), the sensing drive method for the first subpixel SP1 in each of two or more different sensing drive periods SDP1 and SDP2 is the sensing drive in FIG. 6 . method is basically the same.

However, according to the advanced real-time sensing (ARTS), the sensing driving reference voltages VpreS1 and VpreS2 used in each of two or more different sensing driving periods SDP1 and SDP2 may be varied. That is, the first sensing driving reference voltage VpreS1 used in the first sensing driving period SDP1 and the second sensing driving reference voltage VpreS2 used in the second sensing driving period SDP2 may be different. .

In addition, according to the advanced real-time sensing (ARTS), based on the sensing voltages Vsen1 and Vsen2 obtained in each of the two or more different sensing driving periods SDP1 and SDP2, each of the two or more different sensing driving periods SDP1 and SDP2 The mobility corresponding to is not immediately sensed.

In other words, the mobility of the driving transistor DRT in the first subpixel SP1 is not directly sensed based on the first sensing voltage Vsen1 obtained during the first sensing driving period SDP1. Also, based on the second sensing voltage Vsen2 obtained during the second sensing driving period SDP2, the mobility of the driving transistor DRT in the first subpixel SP1 is not directly sensed.

Instead, according to the advanced real-time sensing (ARTS), after the two or more different sensing driving periods SDP1 and SDP2 have all progressed, the sensing voltages Vsen1 and Vsen2 obtained in each of the two or more sensing driving periods SDP1 and SDP2 Based on , the threshold voltage and mobility of the driving transistor DRT in the first subpixel SP1 are simultaneously sensed through arithmetic processing.

Here, sensing the mobility may include sensing a change in mobility. Sensing the threshold voltage may include sensing a change in the threshold voltage. In addition, simultaneously sensing the threshold voltage and mobility may mean simultaneously calculating the threshold voltage or its change and the mobility or its change through arithmetic processing.

The calculation process for simultaneously sensing the threshold voltage and mobility is used in two or more sensing voltages Vsen1 and Vsen2 obtained in each of the two or more sensing driving periods SDP1 and SDP2 and in each of the two or more sensing driving periods SDP1 and SDP2. two or more sensing driving reference voltages (VpreS1, VpreS2), sensing driving data voltages (Vdata_sen1, Vdata_sen2) used in each of the two or more sensing driving periods (SDP1, SDP2), and two or more sensing driving periods (SDP1, SDP2). This is a process of calculating the threshold voltage and mobility using a predetermined boosting time (Δt) and a known capacitance (C) of the line capacitor (Cline) on the first reference voltage line (RVL1).

Here, the two or more sensing voltages Vsen1 and Vsen2 obtained in each of the two or more sensing driving periods SDP1 and SDP2 may be identical to or different from each other. The two or more sensing driving reference voltages VpreS1 and VpreS2 used in each of the two or more sensing driving periods SDP1 and SDP2 may be different from each other. The sensing driving data voltages Vdata_sen1 and Vdata_sen2 used in each of the two or more sensing driving periods SDP1 and SDP2 may be the same. The predetermined boosting times Δt used in the two or more sensing driving periods SDP1 and SDP2 may be equal to each other.

During this calculation process, the compensator (COMP) calculates the already known values (Vdata_sen, VpreS, C, Δt) and the measured value (Vsen) for each of the two or more sensing driving periods (SDP1 and SDP2) in the following formula. Substitute into (1) and (2) to obtain equation (3) generated from equations (1) and (2). In equation (3), there are two unknowns (α, Vth).

The compensator (COMP) calculates the threshold voltage (Vth) and α by obtaining solutions (α, Vth) of simultaneous equations of two or more equations (3) obtained for each of the two or more sensing driving periods (SDP1 and SDP2). and the mobility (μ) can be calculated from α.

In Equations (1) to (3), Id is a current flowing from the drain node N3 to the source node N2 of the driving transistor DRT. Vgs is a voltage difference between the first node N1 and the second node N2 of the driving transistor DRT. Vth is the threshold voltage of the driving transistor DRT. Vdata_sen is a data voltage for sensing driving, and is set to a constant value without changing according to the sensing driving periods SDP1 and SDP2. VpreS is a reference voltage for sensing driving and is a variable value according to the sensing driving periods SDP1 and SDP2. C is the capacitance of the line capacitor Cline of the reference voltage line RVL, and is a value determined according to panel design. dv/dt is a differential value of the voltage of the corresponding reference voltage line (RVL) with respect to time during sensing driving. dv/dt may correspond to a voltage variation (ΔV) of the reference voltage line (RVL) during the boosting time (Δt). That is, dv/dt may correspond to ΔV/Δt. The voltage variation ΔV of the reference voltage line RVL may correspond to a difference value (Vsen−VpreS) between the sensing voltage Vsen and the sensing driving reference voltage VpreS.

In the above equations (1) and (3), α is an item corresponding to (1/2) μ × Cox × W/L. Here, μ is the mobility of the driving transistor DRT, Cox is the capacitance per unit area of the parallel plate capacitor formed by the gate electrode and the channel, W is the channel width of the driving transistor DRT, and L is the driving transistor ( DRT) is the channel length. Since Cox and W/L are fixed values, α can vary mainly depending on the mobility (μ). Therefore, below, α is also described as mobility.

Referring to FIG. 10 , the first sensing driving period SDP1 and the second sensing driving period SDP2 are for simultaneously sensing the threshold voltage and mobility of the driving transistor DRT in the same first subpixel SP1. As the sensing driving period, it may be temporally separated by one or more active periods during which driving for image display is in progress.

Each of the first sensing drive period SDP1 and the second sensing drive period SDP2 may be included in different blank periods separated by one or more active periods. That is, each of the first sensing drive period SDP1 and the second sensing drive period SDP2 may be a timing at which an RT sensing process proceeds.

Below, the sensing driving method for the advanced real-time sensing (ARTS) described above with reference to FIG. 10 will be exemplarily described in more detail with reference to FIGS. 11 and 12 .

Below, the first subpixel SP1 is taken as an example. A drain node or a source node of the second transistor T2 included in the first subpixel SP1 is electrically connected to a first reference voltage line RVL1 among a plurality of reference voltage lines RVL. Also, a drain node or a source node of the first transistor T1 included in the first subpixel SP1 is electrically connected to the first data line DL1 among the plurality of data lines DL.

11 and 12 are driving timing diagrams for advanced real-time sensing (ARTS) of the organic light emitting display device 100 according to embodiments of the present invention.

Each of the two or more sensing driving periods SDP1 and SDP2 for advanced real-time sensing (ARTS) may include initialization periods S1110a and S1110b, tracking periods S1120a and S1120b, and sampling periods S1130a and S1130b. .

In the initialization periods S1110a and S1110b, the voltages of the first node N1 and the second node N2 of the driving transistor DRT are respectively set to the sensing-driving data voltages Vdata_sen1 and Vdata_sen2 and the sensing-driving reference voltage VpreS1. , VpreS2).

The tracking periods S1120a and S1120b are periods during which the voltage of the second node N2 of the driving transistor DRT is boosted for a constant boosting time Δt. In this case, a voltage rising speed of the second node N2 of the driving transistor DRT is proportional to the mobility of the driving transistor DRT.

The sampling period S1130a and S1130b is a period in which the voltage of the second node N2 of the driving transistor DRT, which has been raised during a certain boosting time Δt, is measured (sensed) through the first reference voltage line RVL1. am.

In the tracking periods S1120a and S1120b and the sampling periods S1130a and S1130b, since the second transistor T2 is turned on by the sense signal SENSE of the turn-on level voltage, the first reference voltage line ( The voltage Vrvl of RVL1 may correspond to the voltage of the second node N2 of the driving transistor DRT.

Referring to FIG. 11 , during the initialization period S1110a of the first sensing driving period SDP1, the first transistor T1 is turned on by the scan signal SCAN of the turn-on level voltage, and the first data The first sensing driving data voltage Vdata_sen1 supplied to the line DL1 is applied to the first node N1 of the driving transistor DRT. Then, the second transistor T2 is turned on by the sense signal SENSE of the turn-on level voltage, and the sensing drive reference switch SPRE is turned on, so that the first reference voltage VpreS1 is 1 is supplied to the reference voltage line RVL1 and applied to the second node N2 of the driving transistor DRT.

During the initialization period S1110a of the first sensing drive period SDP1 , the black data voltage may be applied before the first sensing drive data voltage Vdata_sen1 is applied to the first data line DL1 . Here, the black data voltage is obtained by converting the digital black data BLK of FIG. 11 into an analog voltage, and the first sensing driving data voltage Vdata_sen1 is the first digital sensing driving data DATA_SEN1 of FIG. 11 as an analog voltage. is converted to

Referring to FIG. 12 , during the initialization period S1110b of the second sensing drive period SDP2 different from the first sensing drive period SDP1, the scan signal SCAN of the turn-on level voltage is applied to the first transistor T1. ) is turned on, and the second sensing driving data voltage Vdata_sen2 supplied to the first data line DL1 is applied to the first node N1 of the driving transistor DRT. In addition, the second transistor T2 is turned on by the sense signal SENSE of the turn-on level voltage, and the sensing drive reference switch SPRE is turned on, so that a voltage different from the first reference voltage VpreS1 is turned on. The second reference voltage VpreS2 is supplied to the first reference voltage line RVL1 and applied to the second node N2 of the driving transistor DRT.

During the initialization period S1110b of the second sensing drive period SDP2, the black data voltage may be applied before the second sensing drive data voltage Vdata_sen2 is applied to the first data line DL1. Here, the black data voltage is obtained by converting the digital black data BLK of FIG. 12 into an analog voltage, and the second sensing driving data voltage Vdata_sen2 is the analog voltage of the second digital sensing driving data DATA_SEN2 of FIG. 12 is converted to

Referring to FIGS. 11 and 12 , the first sensing driving data voltage Vdata_sen1 and the second sensing driving data voltage Vdata_sen2 may have the same voltage value or may be a voltage value already known to the compensator COMP or the like. .

Referring to FIGS. 11 and 12 , as described above, during the initialization period S1110b of the second sensing drive period SDP2 different from the first sensing drive period SDP1, the first reference voltage VpreS1 differs from the second sensing drive period SDP2. 2 reference voltages VpreS2 may be applied to the first reference voltage line RVL1.

As described above, the organic light emitting display device 100 according to embodiments of the present invention uses different sensing driving reference voltages VpreS1 and VpreS2 in each of two or more different sensing driving periods SDP1 and SDP2, thereby After two or more different sensing driving periods (SDP1 and SDP2) progress, the threshold voltage and mobility may be simultaneously calculated.

That is, in the organic light emitting display device 100 according to embodiments of the present invention, after two or more different sensing driving periods SDP1 and SDP2 have progressed, two different equations (3) having Vth and α as unknowns are used. It is generated more than once, and the threshold voltage and mobility can be calculated at the same time.

As described above, during the initialization period S1110a of the first sensing drive period SDP1, the first sensing drive data voltage Vdata_sen1 is applied to the first data line DL1, and the second sensing drive period SDP2 ) during the initialization period S1110b, when the second sensing-driving data voltage Vdata_sen2 is applied to the first data line DL1, the first sensing-driving data voltage Vdata_sen1 and the second sensing-driving data voltage (Vdata_sen2) may be the same. If two or more different equations (3) having Vth and α as unknowns can be generated, the first sensing driving data voltage Vdata_sen1 and the second sensing driving data voltage Vdata_sen2 may be different.

Referring to FIG. 11 , during the tracking period S1120a of the first sensing driving period SDP1, the first transistor T1 is turned off by the scan signal SCAN of the turn-off level voltage. Accordingly, the first node N1 of the driving transistor DRT is floated. During the tracking period S1120a of the first sensing driving period SDP1, the turn-on state of the second transistor T2 is maintained by the sense signal SENSE of the turn-on level voltage, but the sensing driving reference Since the switch SPRE is turned off and the first reference voltage VpreS1 is not supplied to the first reference voltage line RVL1, the second node N2 of the driving transistor DRT is floated.

Among the aforementioned first sensing driving period SDP1, the tracking period S1120a proceeds for a predetermined boosting time Δt.

During the tracking period S1120a of the first sensing drive period SDP1, that is, during the predetermined boosting time Δt after the initialization period S1110a of the first sensing drive period SDP1, the driving transistor DRT Since the second node N2 is in a floating state, the voltage of the first reference voltage line RVL1 electrically connected to the second node N2 of the driving transistor DRT rises from the first reference voltage VpreS1.

During the tracking period S1120a of the first sensing drive period SDP1, that is, during the predetermined boosting time Δt after the initialization period S1110a of the first sensing drive period SDP1, the first reference voltage line RVL1 ), the voltage rise value is ΔV1.

After the tracking period S1120a of the first sensing driving period SDP1 has elapsed during the boosting time Δt, the increased voltage of the first reference voltage line RVL1 is Vsen1 (=VpreS1+ΔV1).

When the tracking period S1120a is completed during the first sensing driving period SDP1, that is, when the predetermined boosting time Δt elapses after the initialization period S1110a, the sampling step S1130a is performed.

In the sampling step S1130a of the first sensing driving period SDP1, the sampling switch SAM is turned on and the analog-to-digital converter ADC is electrically connected to the first reference voltage line RVL1.

In the sampling step S1130a of the first sensing driving period SDP1, the analog-to-digital converter ADC senses the voltage Vrvl of the first reference voltage line RVL1 and converts the sensed voltage Vsen1 to a digital value. It is converted into a corresponding first sensed value and output.

At this time, the sensed voltage Vsen1 of the first reference voltage line RVL1 by the analog-to-digital converter ADC is a voltage (VpreS1+ΔV1) increased by ΔV1 from the first reference voltage VpreS1.

Referring to FIG. 12 , during the tracking period S1120b of the second sensing driving period SDP2 , the first transistor T1 is turned off by the scan signal SCAN having the turn-off level voltage. Accordingly, the first node N1 of the driving transistor DRT is floated. During the tracking period S1120b of the second sensing driving period SDP2, the turn-on state of the second transistor T2 is maintained by the sense signal SENSE of the turn-on level voltage, but the sensing driving reference Since the switch SPRE is turned off and the second reference voltage VpreS2 is not supplied to the first reference voltage line RVL1, the second node N2 of the driving transistor DRT is floated.

Among the aforementioned second sensing driving period SDP2, the tracking period S1120b proceeds for a predetermined boosting time Δt.

During the tracking period S1120b of the second sensing drive period SDP2, that is, during the predetermined boosting time Δt after the initialization period S1110b of the second sensing drive period SDP2, the driving transistor DRT Since the second node N2 is in a floating state, the voltage of the first reference voltage line RVL1 electrically connected to the second node N2 of the driving transistor DRT rises from the second reference voltage VpreS2.

During the tracking period S1120b of the second sensing drive period SDP2, that is, during the predetermined boosting time Δt after the initialization period S1110b of the second sensing drive period SDP2, the first reference voltage line RVL1 ) is ΔV2.

After the tracking period S1120b during the second sensing driving period SDP2 has elapsed during the boosting time Δt, the increased voltage of the first reference voltage line RVL1 is Vsen2 (=VpreS2+ΔV2).

When the tracking period (S1120b) is completed during the second sensing driving period (SDP2), that is, when the predetermined boosting time (Δt) elapses after the initialization period (S1110b), the sampling step (S1130b) is performed.

In the sampling step S1130b of the second sensing driving period SDP2, the sampling switch SAM is turned on and the analog-to-digital converter ADC is electrically connected to the first reference voltage line RVL1.

In the sampling step S1130b of the second sensing driving period SDP2, the analog-to-digital converter ADC senses the voltage Vrvl of the first reference voltage line RVL1 and converts the sensed voltage Vsen2 to a digital value. It is converted into a corresponding second sensed value and output.

At this time, the sensed voltage Vsen2 of the first reference voltage line RVL1 by the analog-to-digital converter ADC is a voltage (VpreS2+ΔV2) increased by ΔV2 from the second reference voltage VpreS2.

Based on the first sensing value obtained in the first sensing drive period SDP1 and the second sensing value obtained in the second sensing drive period SDP2, the mobility of the driving transistor DRT in the first subpixel SP1 is μ ) and a compensation value for each of the threshold voltages (Vth) may be calculated.

When the compensation value for the mobility (μ) is G and the compensation value for the threshold voltage (Vth) is OFS, the data driving circuit 120 transmits the first subpixel through the first data line DL1. The image driving data voltage Vdata_comp supplied to (SP1) may correspond to a value obtained by multiplying the original data voltage Vdata by G as a gain and adding OFS as an offset (ie, Vdata_comp = G * Vdata + OFS). ).

That is, the gain (G) and offset (OFS) of the image driving data voltage (Vdata_comp) supplied to the first subpixel (SP1) according to the compensation value of the mobility (μ) and the compensation value of the threshold voltage (Vth) this may change.

Therefore, the gain (G) and offset (OFS) of the image driving data voltage (Vdata_comp) supplied to the first subpixel (SP1) is the mobility ( μ) and the change in threshold voltage (Vth).

Regarding the method of simultaneously sensing the threshold voltage (Vth) and the mobility (μ) through the advanced real-time sensing (ARTS) described above, the calculation method based on Equation (1), Equation (2), and Equation (3) Briefly recapitulated from this point of view.

After sensing driving of the first subpixel SP1 is performed using the first sensing driving data voltage Vdata_sen1 and the first reference voltage VpreS1 during the first sensing driving period SDP1, the second transistor T2 After the first sensing value, which is a digital value of the sensing voltage Vsen1 of the first reference voltage line RVL1 electrically connected to the second node N1 of the driving transistor DRT through ) is obtained, the compensator COMP The following equations (4) to (6) can be obtained by substituting the known values (Vdata_sen1, VpreS1, C, △t) and the measured values (Vsen1) into the above equations (1) to (3). there is. In Equations (4) to (5), Id1 is the current flowing through the drain node N3 of the driving transistor DRT during the first sensing driving period SDP1. In Equation (6), the unknowns are Vth (threshold voltage) and α (items including mobility).

After the first sensing drive period SDP1, during the second sensing drive period SDP2 at a different timing, the first subpixel SP1 uses the second sensing drive data voltage Vdata_sen2 and the second reference voltage VpreS2. After the sensing drive for ) is performed, the digital value of the sensing voltage Vsen2 of the first reference voltage line RVL1 electrically connected to the second node N1 of the driving transistor DRT through the second transistor T2 After the second sensing value is obtained, the compensator (COMP) substitutes the already known values (Vdata_sen2, VpreS2, C, Δt) and the measured value (Vsen2) into the above equations (1) to (3), The following equations (7) to (9) can be obtained. In Equations (7) to (8), Id2 is the current flowing through the drain node N3 of the driving transistor DRT during the second sensing driving period SDP2. In Equation (9), the unknowns are Vth (threshold voltage) and α (items including mobility).

Thereafter, the compensator COMP solves the simultaneous equations including Equations (6) and (9) and calculates the two unknowns (Vth, α) as solutions, thereby calculating the threshold voltage (Vth) of the driving transistor DRT. ) and α can be calculated, and the mobility (μ) can be calculated from α.

According to the above-described advanced real-time sensing (ARTS), the driving transistor DRT within the first subpixel SP1 moves during image driving by utilizing the variable technique of the reference voltage VpreS for sensing driving and the RT sensing driving method. It is possible to simultaneously sense the degree (μ) and the threshold voltage (Vth).

Also, the compensator COMP may calculate compensation values for the mobility μ and the threshold voltage Vth of the driving transistor DRT.

Thereafter, the controller 140 changes the image driving data to be supplied to the first subpixel SP1 using the compensation values for the mobility μ and the threshold voltage Vth, and provides the data to the data driving circuit 120. can

When the compensation value for the mobility (μ) is G and the compensation value for the threshold voltage (Vth) is OFS, the data driving circuit 120 transmits the first subpixel through the first data line DL1. The image driving data voltage Vdata_comp supplied to (SP1) may correspond to a value obtained by multiplying the original data voltage Vdata by G as a gain and adding OFS as an offset (ie, Vdata_comp = G * Vdata + OFS). ).

Below, the driving method for the above-described advanced real-time sensing (ARTS) will be briefly described again.

13 is a flowchart of a driving method for advanced real-time sensing (ARTS) of the organic light emitting display device 100 according to embodiments of the present invention.

Referring to FIG. 13 , a driving method for advanced real-time sensing (ARTS) of an organic light emitting display device 100 according to embodiments of the present invention includes a first subpixel (SP) among a plurality of subpixels (SP). A first sensing driving step (S1310) of supplying a first reference voltage (VpreS1) to a first reference voltage line (RVL1) electrically connected to the drain node or the source node of the second transistor (T2) included in SP1); After the first sensing driving step (S1310), the first reference voltage ( A second sensing driving step ( S1320 ) of supplying a second reference voltage VpreS2 different from VpreS1 may be included.

The first sensing driving step (S1310) includes an initialization step (S1110a), a tracking step (S1120a) performed for a predetermined boosting time (Δt) after the initialization step (S1110a), and a boosting time ( A sampling step (S1130a) performed when Δt) has elapsed may be included.

The second sensing driving step (S1320) includes an initialization step (S1110b), a tracking step (S1120b) performed for a predetermined boosting time (Δt) after the initialization step (S1110b), and a boosting time (after the initialization step S1110b) A sampling step (S1130b) performed when Δt) has elapsed may be included.

During the initialization step ( S1110a ) of the first sensing driving step ( S1310 ), the organic light emitting display device 100 supplies the first reference voltage (VpreS1) to the first reference voltage line (RVL1), and the first data line (DL1). ), the first sensing driving data voltage Vdata_sen1 may be supplied.

During the initialization step (S1110b) of the second sensing driving step (S1320), the organic light emitting display device 100 applies a second reference voltage (VpreS2) different from the first reference voltage (VpreS1) as a first reference voltage line (RVL1). and the same second sensing-driving data voltage Vdata_sen2 as the first sensing-driving data voltage Vdata_sen1 may be supplied to the first data line DL1.

During the tracking step S1120a of the first sensing driving step S1310, the voltage of the first reference voltage line RVL1 may increase from the first reference voltage VpreS1.

During the tracking step S1120b of the second sensing driving step S1320, the voltage of the first reference voltage line RVL1 may increase from the second reference voltage VpreS2.

During the sampling step (S1130a) of the first sensing driving step (S1310), the analog-to-digital converter (ADC) may sense the voltage (Vrvl) of the first reference voltage line (RVL1) and output a first sensed value.

During the sampling step S1130b of the second sensing driving step S1320, the analog-to-digital converter ADC may sense the voltage Vrvl of the first reference voltage line RVL1 and output a second sensed value.

Referring to FIG. 13 , after the first sensing driving step ( S1310 ) and the second sensing driving step ( S1320 ), a simultaneous sensing step ( S1330 ) and a simultaneous compensation processing step ( S1340 ) may proceed.

In the simultaneous sensing step (S1330), the organic light emitting display device 100, based on the first sensing value obtained in the first sensing driving step (S1310) and the second sensing value obtained in the second sensing driving step (S1320), The mobility and threshold voltage of the driving transistor DRT in one sub-pixel SP1 may be simultaneously sensed. As described above, such simultaneous sensing may be performed in a manner of obtaining solutions of simultaneous equations.

In the simultaneous sensing step ( S1330 ), the organic light emitting display device 100 calculates compensation values for the mobility and threshold voltage of the driving transistor DRT in the first subpixel SP1 and stores them in the memory MEM. can

In the simultaneous compensation processing step S1340, the organic light emitting display device 100 performs image driving data to be supplied to the first subpixel SP1 based on compensation values for the mobility and threshold voltage of the driving transistor DRT. The gain and offset of the voltage may be changed and supplied to the first data line DL1.

The gain and offset of the data voltage for driving the image may vary according to a change in the mobility μ and the threshold voltage Vth of the driving transistor DRT included in the first subpixel SP1.

The driving circuit 111 providing the driving method for the above-described progressive real-time sensing (ARTS) will be briefly described.

14 is a diagram illustrating a driving circuit 111 for advanced real-time sensing (ARTS) of the organic light emitting display device 100 according to embodiments of the present invention.

Referring to FIG. 14 , a driving circuit 111 for advanced real-time sensing (ARTS) of the organic light emitting display device 100 according to embodiments of the present invention includes a first arbitrary one of a plurality of subpixels (SP). a data driving circuit 120 supplying a sensing driving data voltage Vdata_sen to a first data line DL1 electrically connected to the drain node or the source node of the first transistor T1 included in the subpixel SP1; and , The reference voltage supply for supplying the sensing driving reference voltage VpreS to the first reference voltage line RVL1 electrically connected to the drain node or the source node of the second transistor T2 included in the first subpixel SP1. circuit 1400.

The reference voltage supply circuit 1400 may supply the first reference voltage VpreS1 to the first reference voltage line RVL1 during the initialization period S1110a of the first sensing driving period SDP1.

The data driving circuit 120 may supply the first sensing driving data voltage Vdata_sen1 to the first data line DL1 during the initialization period S1110a of the first sensing driving period SDP1 .

The reference voltage supply circuit 1400 generates the first reference voltage VpreS1 as the first reference voltage line RVL1 during the initialization period S1110b of the second sensing drive period SDP2 different from the first sensing drive period SDP1. A second reference voltage VpreS2 different from that may be supplied.

During the initialization period S1110b of the second sensing drive period SDP2, the data driving circuit 120 outputs the second sensing driving data voltage Vdata_sen1 and the first sensing driving data voltage Vdata_sen1 to the first data line DL1. A voltage (Vdata_sen2) can be supplied.

According to the above-described embodiments of the present invention, there is an effect of providing a driving circuit 111, an organic light emitting display device 100, and a driving method that enable accurate sensing and compensation while reducing the time required for sensing. .

In addition, according to embodiments of the present invention, there is an effect of providing a driving circuit 111 capable of sensing a threshold voltage of a transistor in real time during image driving, an organic light emitting display device 100, and a driving method.

In addition, according to embodiments of the present invention, an effect of providing a driving circuit 111, an organic light emitting display device 100, and a driving method capable of simultaneously sensing the threshold voltage and mobility of a transistor in real time during image driving is provided. there is.

In addition, according to the embodiments of the present invention, it is possible to immediately compensate for a threshold voltage change during image driving, and by simultaneously sensing the threshold voltage and mobility in the same sensing driving process, the time or number of times required for the sensing driving process is reduced. There is an effect that can be given.

The above description and accompanying drawings are merely illustrative of the technical idea of the present invention, and those skilled in the art can combine the configuration within the scope not departing from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: organic light emitting display device
110: display panel
120: data driving circuit
130: gate driving circuit
140: controller
410: sensing circuit
1400: reference voltage supply circuit

Claims (15)

a display panel on which a plurality of data lines and a plurality of gate lines are disposed, a plurality of reference voltage lines are disposed, and a plurality of subpixels are disposed;
a data driving circuit for driving the plurality of data lines; and
A gate driving circuit for driving the plurality of gate lines;
The plurality of subpixels,
An organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first transistor electrically connected between a first node of the driving transistor and a corresponding data line among the plurality of data lines, and a second transistor of the driving transistor a second transistor electrically connected between a node and a corresponding reference voltage line among the plurality of reference voltage lines, and a capacitor electrically connected between a first node and a second node of the driving transistor;
a reference switch for sensing drive electrically connected between a reference voltage supply node and the reference voltage line;
an analog-to-digital converter sensing the voltage of the reference voltage line; and
Further comprising a sampling switch electrically connected between the reference voltage line and the analog-to-digital converter;
A drain node or a source node of the second transistor included in any first subpixel among the plurality of subpixels is electrically connected to a first reference voltage line among the plurality of reference voltage lines;
During an initialization period of a first sensing driving period, a first reference voltage is applied to the first reference voltage line;
During an initialization period of a second sensing driving period different from the first sensing driving period, a second reference voltage different from the first reference voltage is applied to the first reference voltage line;
The organic light emitting display device of claim 1 , wherein each of the first sensing driving period and the second sensing driving period is included in a different blank period.
delete According to claim 1,
A drain node or a source node of the first transistor included in the first subpixel is electrically connected to a first data line among the plurality of data lines;
During an initialization period of the first sensing drive period, a data voltage for a first sensing drive is applied to the first data line;
An organic light emitting display device wherein, during an initialization period of the second sensing driving period, a second sensing driving data voltage equal to the first sensing driving data voltage is applied to the first data line.
According to claim 3,
During a predetermined boosting time after an initialization period during the first sensing driving period, a voltage of the first reference voltage line is increased from the first reference voltage;
During the boosting time after the initialization period during the second sensing driving period, the voltage of the first reference voltage line is increased at the second reference voltage different from the first reference voltage.
According to claim 4,
When the boosting time elapses after the initialization period during the first sensing driving period, the sampling switch is turned on so that the first reference voltage line is electrically connected to the analog-to-digital converter, and the analog-to-digital converter Sensing the voltage of the first reference voltage line and outputting a first sensed value;
When the boosting time elapses after the initialization period during the second sensing driving period, the sampling switch is turned on so that the first reference voltage line is electrically connected to the analog-to-digital converter, and the analog-to-digital converter An organic light emitting display device configured to sense a voltage of a first reference voltage line and output a second sensed value.
According to claim 5,
An organic light emitting display device wherein a gain and an offset of a data voltage for driving an image supplied to the first subpixel are changed based on the first sensed value and the second sensed value.
According to claim 6,
The organic light emitting display device of claim 1 , wherein gain and offset of the image driving data voltage supplied to the first subpixel vary according to changes in mobility and threshold voltage of the driving transistor included in the first subpixel.
a display panel on which a plurality of data lines and a plurality of gate lines are disposed, a plurality of reference voltage lines are disposed, and a plurality of subpixels are disposed; a data driving circuit for driving the plurality of data lines; and a gate driving circuit for driving the plurality of gate lines, wherein the plurality of subpixels include an organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first node of the driving transistor and the plurality of subpixels. A first transistor electrically connected between corresponding data lines among data lines of the driving transistor, a second transistor electrically connected between a second node of the driving transistor and a corresponding reference voltage line among the plurality of reference voltage lines, and the driving transistor A driving method of an organic light emitting display device including a capacitor electrically connected between a first node and a second node,
a first sensing driving step of supplying a first reference voltage to a first reference voltage line electrically connected to a drain node or a source node of the second transistor included in any first subpixel among the plurality of subpixels; and
After the first sensing and driving step, a second reference voltage different from the first reference voltage is supplied to the first reference voltage line electrically connected to a drain node or a source node of the second transistor included in the first subpixel. Including a second sensing driving step to do,
The first sensing driving step is performed in a first blank period,
The second sensing and driving step is performed in a second blank period different from the first blank period.
According to claim 8,
A drain node or a source node of the first transistor included in the first subpixel is electrically connected to a first data line among the plurality of data lines;
Each of the first sensing driving step and the second sensing driving step includes an initialization step, a tracking step performed for a predetermined boosting time after the initialization step, and a sampling step performed when the boosting time elapses after the initialization step. including,
During the initialization phase of the first sensing driving phase,
supplying the first reference voltage to the first reference voltage line and supplying a data voltage for a first sensing drive to the first data line;
During the initialization phase of the second sensing driving phase,
The second reference voltage, which is different from the first reference voltage, is supplied to the first reference voltage line, and the second data voltage for sensing and driving, which is the same as the data voltage for driving the first sensing, is supplied to the first data line. A method of driving a light emitting display device.
According to claim 9,
During the tracking step of the first sensing driving step, the voltage of the first reference voltage line is increased from the first reference voltage,
During the tracking step of the second sensing driving step, the voltage of the first reference voltage line is increased at the second reference voltage different from the first reference voltage.
According to claim 10,
During the sampling step of the first sensing driving step, the analog-to-digital converter senses the voltage of the first reference voltage line and outputs a first sensed value;
During the sampling step of the second sensing driving step, the analog-to-digital converter senses the voltage of the first reference voltage line and outputs a second sensed value.
According to claim 11,
After the first sensing driving step and the second sensing driving step,
and a compensation processing step of changing the gain and offset of the image driving data voltage to be supplied to the first subpixel and supplying the gain and offset to the first data line based on the first sensed value and the second sensed value. A method of driving a light emitting display device.
delete a display panel on which a plurality of data lines and a plurality of gate lines are disposed, a plurality of reference voltage lines are disposed, and a plurality of subpixels are disposed; a data driving circuit for driving the plurality of data lines; and a gate driving circuit for driving the plurality of gate lines, wherein the plurality of subpixels include an organic light emitting diode, a driving transistor for driving the organic light emitting diode, a first node of the driving transistor and the plurality of subpixels. A first transistor electrically connected between corresponding data lines among data lines of the driving transistor, a second transistor electrically connected between a second node of the driving transistor and a corresponding reference voltage line among the plurality of reference voltage lines, and the driving transistor A driving circuit of an organic light emitting display device including a capacitor electrically connected between a first node and a second node,
a data driving circuit supplying a data voltage for sensing driving to a first data line electrically connected to a drain node or a source node of the first transistor included in any first subpixel among the plurality of subpixels; and
a reference voltage supply circuit supplying a reference voltage to a first reference voltage line electrically connected to a drain node or a source node of the second transistor included in the first subpixel;
The reference voltage supply circuit,
During an initialization period of a first sensing driving period, a first reference voltage is supplied to the first reference voltage line;
supplying a second reference voltage different from the first reference voltage to the first reference voltage line during an initialization period of a second sensing driving period different from the first sensing driving period;
The first sensing driving period and the second sensing driving period are each included in different blank periods.
According to claim 14,
The data driving circuit,
During an initialization period of the first sensing drive period, a data voltage for a first sensing drive is supplied to the first data line;
A driving circuit supplying a second sensing driving data voltage identical to the first sensing driving data voltage to the first data line during an initialization period of the second sensing driving period.

Images