KR102785332B1 - Organic light emitting display device - Google Patents

Abstract

The present application relates to an organic light emitting display device having a corresponding degradation model for each display panel or for each area within one display panel, and the organic light emitting display device according to the present application includes a plurality of pixels including an organic light emitting diode and a driving transistor, and the driving transistor controls a current flowing from a power line to which a first high-potential power voltage is supplied to the organic light emitting diode based on a voltage difference between a gate electrode and a source electrode of the driving transistor, and can operate in a linear region in at least a part of a driving section in which a second high-potential power voltage lower than the first high-potential power voltage is supplied to the power line.

Description

ORGANIC LIGHT EMITTING DISPLAY DEVICE

The present application relates to an organic light emitting display device.

In the information society, many display device technologies are being developed to display visual information as images or pictures. Among display devices, organic light-emitting diodes (OLEDs) display images by using organic light-emitting diodes that emit light through the recombination of electrons and holes. Organic light-emitting diodes have a fast response speed and are capable of expressing low-level tones through self-luminous light, so they are gaining attention as next-generation displays.

An organic light emitting display device includes a display panel having data lines, scan lines, a plurality of sub-pixels formed at intersections of the data lines and the scan lines, a gate driver supplying scan signals to the scan lines, and a data driver supplying data voltages to the data lines. Each of the pixels includes an organic light emitting diode, a driving transistor controlling an amount of current supplied to the organic light emitting diode according to a voltage of a gate electrode, and a scan transistor supplying a data voltage of a data line to a gate electrode of the driving transistor in response to a scan signal of the scan line.

The threshold voltage of a driving transistor may vary for each pixel due to reasons such as process deviation during the manufacturing of an organic light-emitting display device or deterioration of the driving transistor due to long-term operation. That is, when the same data voltage is applied to the pixels, the current supplied to the organic light-emitting diode should be the same, but due to the difference in the threshold voltage of the driving transistor between the pixels, even when the same data voltage is applied to the pixels, the current supplied to the organic light-emitting diode may vary for each pixel. In addition, the organic light-emitting diode may also deteriorate due to long-term operation, in which case the luminance of the organic light-emitting diode may vary for each pixel. Accordingly, even when the same data voltage is applied to the pixels, the luminance emitted by the organic light-emitting diode may vary for each pixel. To solve this problem, a compensation method for compensating for the threshold voltage of the driving transistor and the deterioration of the organic light-emitting diode has been prepared.

The threshold voltage of the driving transistor and the deterioration of the organic light-emitting diode can be compensated for by an external compensation method. The external compensation method is a method of supplying a preset data voltage to a pixel, sensing the source voltage of the driving transistor through a predetermined sensing line according to the preset data voltage, converting the sensed voltage into digital data, which is sensing data, using an analog-digital converter, and compensating for digital video data to be supplied to the pixel according to the sensing data.

Existing compensation methods compensate for each organic light-emitting diode assuming that the same deterioration occurs for each display panel or within a single display panel. Therefore, compensation errors occur when the deterioration rate varies for each display panel or within a single display panel due to process deviations of the organic light-emitting diode.

The present application seeks to provide an organic light emitting display device having a corresponding degradation model for each display panel or for each area within one display panel.

An organic light-emitting display device according to the present application includes a plurality of pixels, each of the plurality of pixels including a display panel including a driving transistor, a first transistor, a second transistor, a capacitor connected to a gate electrode of the driving transistor, and an organic light-emitting diode, a scan signal output unit providing a scan signal to the first transistor, and a sensing signal output unit providing a sensing signal to the second transistor, wherein the driving transistor can operate in a linear region during at least a part of a driving section.

An organic light-emitting display device according to the present application may include a display panel including a plurality of pixels, each of the plurality of pixels including a driving transistor, a first transistor, a second transistor, a capacitor connected to a gate electrode of the driving transistor, and an organic light-emitting diode, a scan signal output unit providing a scan signal to the first transistor, a sensing signal output unit providing a sensing signal to the second transistor, and a compensation circuit for operating the driving transistor in a linear region in a sensing mode, sensing current of each of the plurality of pixels through the driving transistor operating in the linear region, and generating and outputting a sensing voltage from the sensed current, in relation to measurement of a threshold voltage of the driving transistor and a degradation characteristic of the organic light-emitting diode.

An organic light-emitting display device according to the present application includes a plurality of pixels including an organic light-emitting diode and a driving transistor, wherein the organic light-emitting diode includes an anode electrode connected to a source electrode of the driving transistor, a cathode electrode supplied with a low-potential power voltage lower than a first high-potential power voltage, and a light-emitting layer, and the driving transistor controls a current flowing from a power line supplied with the first high-potential power voltage to the organic light-emitting diode based on a voltage difference between a gate electrode and a source electrode of the driving transistor, and can operate in a linear region in at least a part of a driving section in which a second high-potential power voltage lower than the first high-potential power voltage is supplied to the power line.

The organic light-emitting display device according to the present application has a corresponding deterioration model for each display panel or for each area within one display panel. When deterioration compensation is performed using a model that corrects the deviation, deterioration compensation error due to a difference in deterioration speed due to process deviation of the organic light-emitting diode (OLED) and the resulting afterimage phenomenon can be prevented.

Figure 1 is a block diagram of an organic light emitting display device according to the present application.
Figure 2 is a plan view of an organic light-emitting display device according to the present application.
FIG. 3 is a circuit diagram showing a pixel, a source driver IC, a reference voltage generator, and an analog-to-digital converter according to an example of the present application.
FIG. 4 is a waveform diagram showing a scan signal, a sensing signal, a first switch control signal, a second switch control signal, a gate voltage, and a source voltage supplied to a pixel in a sensing mode.
FIG. 5 is a circuit diagram showing driving of a first period of a pixel according to an example of the present application.
FIG. 6 is a circuit diagram showing the driving of a second period of a pixel according to an example of the present application.
Figure 7 is a graph showing the change in brightness of each organic light-emitting diode over time in an organic light-emitting display device according to the present application.
FIG. 8 is a graph showing the source voltage of the driving transistor of the organic light-emitting display device according to the present application and the current flowing to each organic light-emitting diode.
FIG. 9 is a plan view showing a compensation circuit, a plurality of driving transistors, and a plurality of organic light-emitting diodes of an organic light-emitting display device according to the present application.
Fig. 10 is a waveform diagram showing the driving of a compensation circuit of an organic light-emitting display device according to the present application.
Fig. 11 is a plan view showing a compensation method of a display panel of an organic light-emitting display device according to the present application.
FIG. 12 is a graph showing the relationship between changes in threshold voltage of an organic light-emitting display device according to the present application and deterioration of an organic light-emitting diode.

The advantages and features of the present application and the method for achieving them will become clear with reference to the embodiments described in detail below together with the accompanying drawings. However, the present application is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present invention complete and to fully inform a person having ordinary skill in the art to which the present application belongs of the scope of the invention, and the present application is defined only by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present application are exemplary, and the present invention is not limited to the matters illustrated. The same reference numerals refer to the same components throughout the specification. In addition, in explaining the present invention, if it is judged that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

In this specification, when the words "includes," "has," and "consists of," are used, other parts may be added unless "only" is used. When a component is expressed in the singular, it includes the plural unless there is a special explicit description.

When interpreting a component, it is interpreted as including the error range even if there is no separate explicit description.

When describing a positional relationship, for example, when the positional relationship between two parts is described as 'on ~', 'upper ~', 'lower ~', 'next to ~', etc., one or more other parts may be located between the two parts, unless 'right' or 'directly' is used.

When describing a temporal relationship, for example, when describing a temporal relationship using phrases such as 'after', 'following', 'next to', or 'before', it can also include cases where there is no continuity, as long as 'right away' or 'directly' is not used.

Although the terms first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, a first component referred to below may also be a second component within the technical scope of the present application.

“X-axis direction”, “Y-axis direction” and “Z-axis direction” should not be interpreted as merely geometric relationships in which the relationship between them is perpendicular to each other, but may mean a wider directionality within the range in which the configuration of the present invention can function functionally.

The term "at least one" should be understood to include all combinations that can be presented from one or more of the associated items. For example, the meaning of "at least one of the first, second, and third items" can mean not only each of the first, second, or third items, but also all combinations of items that can be presented from two or more of the first, second, and third items.

The individual features of the various embodiments of the present application may be partially or wholly combined or combined with each other, and may be technically interconnected and driven in various ways, and each embodiment may be implemented independently of each other or implemented together in a related relationship.

Hereinafter, embodiments of the present application will be described in detail with reference to the attached drawings.

Fig. 1 is a block diagram of an organic light emitting display device according to the present application. Fig. 2 is a plan view of an organic light emitting display device according to the present application. The organic light emitting display device according to the present application includes a display panel (10), a data driver (20), a gate driver (40), a source printed circuit board (S-PCB) (50), a timing controller (T-con) (60), an external compensation circuit (70), a reference voltage generator (80), and a control printed circuit board (C-PCB) (90).

The display panel (10) includes a display area (DA) and a non-display area (NDA). The display area (DA) is an area where pixels (P) are formed to display an image. The non-display area (NDA) is an area provided around the display area (DA). The display panel (10) is provided with data lines (D1 to Dm, m is a positive integer greater than or equal to 2), reference voltage lines (R1 to Rp, p is a positive integer greater than or equal to 2), scan lines (S1 to Sn, n is a positive integer greater than or equal to 2), and sensing signal lines (SE1 to SEn). The data lines (D1 to Dm) and the reference voltage lines (R1 to Rp) may intersect the scan lines (S1 to Sn) and the sensing signal lines (SE1 to SEn). The data lines (D1 to Dm) and the reference voltage lines (R1 to Rp) may be parallel to each other. The scan lines (S1 to Sn) and the sensing signal lines (SE1 to SEn) can be parallel to each other.

Each of the pixels (P) can be connected to any one of the data lines (D1 to Dm), any one of the reference voltage lines (R1 to Rp), any one of the scan lines (S1 to Sn), and any one of the sensing signal lines (SE1 to SEn). The pixels (P) are provided on a lower substrate (11) of the display panel (10). Each of the pixels (P) can include an organic light emitting diode (OLED) and a plurality of transistors for supplying current to the organic light emitting diode (OLED).

The data driving unit (20) may include a plurality of source driver ICs (Source Driver Integrated Circuits, SDICs) (21). The source driver IC (21) receives compensation digital video data (CDATA), sensing digital video data (PDATA), and a data timing control signal (DCS) from a timing controller (60). The source driver IC (21) is connected to data lines (D1 to Dm) and supplies data voltages. Each of the source driver ICs (21) may be mounted on each of the flexible films (22).

Each of the flexible films (22) may be a tape carrier package or a chip on film. Each of the flexible films (22) may be bendable or flexible. Each of the flexible films (22) may be attached to a lower substrate (11) and a source printed circuit board (50). Each of the flexible films (22) may be attached to the lower substrate (11) by a TAB (tape automated bonding) method using an anisotropic conductive film, thereby allowing the source driver ICs (21) to be connected to the data lines (D1 to Dm). The source printed circuit board (50) may be connected to a control printed circuit board (90) by a flexible cable (91).

The data driving unit (20) is connected to the reference voltage lines (R1 to Rp) and senses the source voltage of the driving transistors of the pixels (P). The data driving unit (20) generates sensing data (SD) using the sensed voltage and supplies the sensing data (SD) to an external compensation circuit (70).

The gate driving unit (40) includes a scan signal output unit (41) and a sensing signal output unit (42).

The scan signal output unit (41) is connected to the scan lines (S1 to Sn) and supplies scan signals. The scan signal output unit (41) supplies scan signals to the scan lines (S1 to Sn) according to a scan timing control signal (SCS) input from the timing controller (60).

The sensing signal output unit (42) is connected to the sensing signal lines (SE1 to SEn) and supplies sensing signals. The sensing signal output unit (42) supplies sensing signals to the sensing signal lines (SE1 to SEn) according to a sensing timing control signal (SENCS) input from a timing controller (60).

The scan signal output unit (41) and the sensing signal output unit (42) may be formed directly in the non-display area (NDA) of the display panel (10) in a GIP (Gate driver In Panel) manner, including a plurality of transistors. Alternatively, the scan signal output unit (41) and the sensing signal output unit (42) may be formed in the form of a driving chip and mounted on a flexible film connected to the display panel (10).

The timing controller (60) receives compensation digital video data (CDATA), sensing digital video data (PDATA), and timing signals from an external compensation circuit (70). The timing signals may include a vertical sync signal, a horizontal sync signal, a data enable signal, and a dot clock.

The timing controller (60) generates timing control signals for controlling the operation timing of the data driving unit (20), the scan signal output unit (41), and the sensing signal output unit (42). The timing control signals include a data timing control signal (DCS) for controlling the operation timing of the data driving unit (20), a scan timing control signal (SCS) for controlling the operation timing of the scan signal output unit (41), and a sensing timing control signal (SENCS) for controlling the operation timing of the sensing signal output unit (42).

The timing controller (60) outputs compensation digital video data (CDATA), sensing digital video data (PDATA), and a data timing control signal (DCS) to the data driving unit (20). The timing controller (60) outputs a scan timing control signal (SCS) to the scan signal output unit (41). It outputs a sensing timing control signal (SENCS) to the sensing signal output unit (42). In addition, the timing controller (60) can output a switch control signal (SCS) for controlling a switch of the data driving unit (20).

The timing controller (60) can control the organic light emitting display device according to the present application in either a display mode or a sensing mode.

Display mode is a mode in which pixels (P) emit light by supplying data voltages according to compensation digital video data (CDATA) to the pixels (P).

The sensing mode supplies sensing data voltages according to sensing digital video data (PDATA) to the pixels (P). In the sensing mode, the threshold voltage of the driving transistor of each pixel (P) is sensed through the reference voltage lines (R1 to Rp) connected to each pixel (P). In addition, in the sensing mode, the source voltage of the driving transistor is sensed to compensate for the electron mobility of the driving transistor of each pixel (P) or the deterioration of the organic light emitting diode of each pixel (P). The source voltage of the driving transistor sensed in the sensing mode can be converted into sensing data (SD) by the analog-to-digital converter (140) and stored in the memory of the external compensation circuit (70). The sensing mode can be performed before the power of the organic light emitting display device is turned off, performed immediately after the power of the organic light emitting display device is turned on, or performed at a predetermined cycle while the power of the organic light emitting display device is turned on.

An external compensation circuit (70) receives sensing data (SD) from a data driving unit (20). The external compensation circuit (70) generates compensation data to compensate digital video data (DATA) using the sensing data (SD). The external compensation circuit (70) applies the compensation data to the digital video data (DATA) to generate compensation digital video data (CDATA) and sensing digital video data (PDATA). The external compensation circuit (70) outputs the compensation digital video data (CDATA) and sensing digital video data (PDATA) to a timing controller (60).

The external compensation circuit (70) may include a memory that stores sensing data (SD). The memory of the external compensation circuit (70) may be a nonvolatile memory such as an electrically erasable programmable read-only memory (EEPROM). The external compensation circuit (70) may be built into the timing controller (60).

The reference voltage generation unit (80) generates a reference voltage and supplies it to the source driver ICs (21). The reference voltage generation unit (80) generates a low voltage or a high voltage for setting a sensing voltage range in a sensing mode. In addition to the reference voltage, the reference voltage generation unit (80) can generate driving voltages necessary for driving the organic light-emitting display device according to the present application and supply them to necessary components.

The timing controller (60), external compensation circuit (70), and reference voltage generator (80) may be mounted on a control printed circuit board (90). The control printed circuit board (90) may be connected to a source printed circuit board (50) by a flexible cable (91).

An organic light-emitting display device according to the present application converts digital video data (DATA) into compensation video data (CDATA) using sensing data (SD) sensed in a sensing mode. As a result, the present application can compensate for the threshold voltage of each driving transistor of pixels (P), the electron mobility of each driving transistor, and the deterioration of the organic light-emitting diode.

FIG. 3 is a circuit diagram showing a pixel (P), a source driver IC (21), a reference voltage generator (80), and an analog-digital converter (ADC) (140) according to an example of the present application. In FIG. 3, for convenience of explanation, only a sub-pixel, a source driver IC (21), a reference voltage generator (80), an analog-digital converter (140), a first switch (SW1), and a second switch (SW2) connected to a jth (j is a positive integer satisfying 1^j≤?m) data line (Dj), a jth reference voltage line (Rj), a kth (k is a positive integer satisfying 1^k≤?n) scan line (Sk), and a kth sensing signal line (SEk) are shown.

Referring to FIG. 3, a pixel (P) may include an organic light emitting diode (OLED), a driving transistor (DT), first and second switching transistors (ST1, ST2), and a storage capacitor (Cst).

An organic light emitting diode (OLED) emits light according to a current supplied through a driving transistor (DT). The OLED may include an anode electrode, a hole transporting layer, an organic light emitting layer, an electron transporting layer, and a cathode electrode. When voltage is applied to the anode and the cathode electrodes of the OLED, holes and electrons move to the organic light emitting layer through the hole transporting layer and the electron transporting layer, respectively, and combine with each other in the organic light emitting layer to emit light. The anode electrode of the OLED is connected to the source electrode of the driving transistor (DT), and the cathode electrode is supplied with a low potential power supply voltage (ELVSS) that is lower than a high potential power supply voltage (ELVDD).

A driving transistor (DT) controls a current flowing from a high-potential power supply voltage (ELVDD) line to an organic light-emitting diode (OLED) according to a voltage difference between a gate electrode and a source electrode. A gate electrode of the driving transistor (DT) may be connected to a first electrode of a first switching transistor (ST1), a source electrode may be connected to an anode electrode of the organic light-emitting diode (OLED), and a drain electrode may be connected to the high-potential power supply voltage (ELVDD) line.

The first switching transistor (ST1) is turned on by the kth scan signal of the kth scan line (Sk) to connect the jth data line (Dj) to the gate electrode of the driving transistor (DT). The gate electrode of the first switching transistor (T1) may be connected to the kth scan line (Sk), the first electrode may be connected to the gate electrode of the first driving transistor (DT1), and the second electrode may be connected to the jth data line (Dj).

The second switching transistor (ST2) is turned on by the kth sensing signal of the kth sensing signal line (SEk) to connect the jth reference voltage line (Rj) to the source electrode of the driving transistor (DT). The gate electrode of the second switching transistor (ST2) may be connected to the kth sensing signal line (SEk), the first electrode may be connected to the jth reference voltage line (Rj), and the second electrode may be connected to the source electrode of the driving transistor (DT).

It should be noted that the first electrode of each of the first and second switching transistors (ST1, ST2) may be a source electrode and the second electrode may be a drain electrode, but is not limited thereto. That is, the first electrode of each of the first and second switching transistors (ST1, ST2) may be a drain electrode and the second electrode may be a source electrode.

A storage capacitor (Cst) is formed between the gate electrode and the source electrode of the driving transistor (DT). The storage capacitor (Cst) stores the differential voltage between the gate voltage and the source voltage of the driving transistor (DT).

The driving transistor (DT) and the first and second switching transistors (ST1, ST2) may be formed as thin film transistors. In addition, although FIG. 3 has been described mainly with reference to the case where the driving transistor (DT) and the first and second switching transistors (ST1, ST2) are formed as N-type MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), it should be noted that the present invention is not limited thereto. The driving transistor (DT) and the first and second switching transistors (ST1, ST2) may also be formed as P-type MOSFETs.

The source driver IC (21) converts compensation video data (CDATA) into data voltages according to a data timing control signal (DCS) in the display mode and supplies them to the data lines (D1 to Dm). The display mode is a mode in which pixels (P) emit light to display an image. The data voltage is a voltage for causing the organic light emitting diode (OLED) of the pixel (P) to emit light at a predetermined brightness.

The source driver IC (21) converts sensing video data (PDATA) into sensing data voltage according to a data timing control signal (DCS) in the sensing mode and supplies the same to the data lines (D1 to Dm). The sensing mode may be any one of a threshold voltage compensation mode in which the source voltage of the driving transistor (DT) is sensed to compensate for the threshold voltage of the driving transistor of each of the pixels (P), a mobility compensation mode in which the source voltage of the driving transistor (DT) is sensed to compensate for the electron mobility of the driving transistor of each of the pixels (P), and a deterioration compensation mode in which the source voltage of the driving transistor (DT) is sensed to compensate for deterioration of the organic light-emitting diode of each of the pixels (P).

The analog-to-digital converter (140) converts voltages sensed from the reference voltage lines (R1 to Rp) in sensing mode into digital data, sensing data (SD), and outputs them to an external compensation circuit (70).

The first switch (SW1) is connected between the reference voltage lines (R1 to Rp) and the reference voltage generator (80) and switches the connection between the reference voltage lines (R1 to Rp) and the reference voltage generator (80). The first switch (SW1) can be turned on and off by a first switch control signal (SCS1) input from a timing controller (60). When the first switch (SW1) is turned on by the first switch control signal (SCS1), the reference voltage lines (R1 to Rp) are connected to the reference voltage generator (80), so that the reference voltage generated by the reference voltage generator (80) can be supplied to the reference voltage lines (R1 to Rp).

The second switches (SW2) are connected between the reference voltage lines (R1 to Rp) and the analog-to-digital converter (140) to switch the connection between the reference voltage lines (R1 to Rp) and the analog-to-digital converter (140). The second switches (SW2) can be turned on and off by a second switch control signal (SCS2) input from a timing controller (60). When the second switches (SW2) are turned on by the second switch control signal (SCS2), the reference voltage lines (R1 to Rp) are connected to the analog-to-digital converter (140), so that the source voltage of the driving transistor of each of the pixels (P) can be sensed through each of the reference voltage lines (R1 to Rp).

FIG. 4 is a waveform diagram showing a scan signal (SCANk), a sensing signal (SENSk), a first switch control signal (SCS1), a second switch control signal (SCS2), a gate voltage (Vg), and a source voltage (Vs) supplied to a pixel (P) in sensing mode.

In the sensing mode, one frame period may include first and second periods (t1, t2). The first period (t1) is a period for initializing the source electrode of the driving transistor (DT) to the reference voltage (VREF). The second period (t2) is a period for applying the sensing data voltage (SVdata) to the gate electrode of the driving transistor (DT) and sensing the source voltage of the driving transistor (DT).

The kth scan signal (SCANk) of the kth scan line (Sk) is supplied with the gate-on voltage (Von) during the second period (t2). The kth scan signal (SCANk) of the kth scan line (Sk) is exemplified as being supplied with the gate-off voltage (Voff) during the first period (t1), but may be supplied with the gate-on voltage (Von). The kth sensing signal (SENSk) of the kth sensing signal line (SEk) is supplied with the gate-on voltage (Von) during the first and second periods (t1, t2). The first and second switching transistors (ST1, ST2) of the pixel (P) can be turned on by the gate-on voltage (Von) and turned off by the gate-off voltage (Voff).

The first switch control signal (SCS1) is supplied with a first logic level voltage (V1) during a first period (t1) and with a second logic level voltage (V2) during a second period (t2). The second switch control signal (SCS2) is supplied with a second logic level voltage (V2) during the first period (t1) and with the first logic level voltage (V1) during the second period (t2). Each of the first and second switches (SW1, SW2) can be turned on by the first logic level voltage and turned off by the second logic level voltage.

FIG. 5 is a circuit diagram showing driving of a first period (t1) of a pixel according to an example of the present application.

During a first period (t1), a first switching transistor (ST1) is turned off by a k-th scan signal (SCANk) of a gate-off voltage (Voff) supplied to a k-th scan line (Sk). A second switching transistor (ST2) is turned on by a k-th sensing signal (SENSk) of a gate-on voltage (Von) supplied to a k-th sensing signal line (SEk). During a first period (t1), a first switch (SW1) is turned on by a first switch control signal (SCS1) of a first logic level voltage (V1). A second switch (SW2) is turned off by a second switch control signal (SCS2) of a second logic level voltage (V2).

During the first period (t1), the reference voltage (VREF) is supplied from the reference voltage generator (80) to the jth reference voltage line (Rj) due to the turn-on of the first switch (SW1). During the first period (t1), the reference voltage (VREF) of the jth reference voltage line (Rj) is supplied to the source electrode of the driving transistor (DT) due to the turn-on of the second switching transistor (ST2). That is, the source electrode of the driving transistor (DT) is initialized to the reference voltage (VREF).

FIG. 6 is a circuit diagram showing driving of a second period (t) of a pixel according to an example of the present application.

During the second period (t2), the first switching transistor (ST1) is turned on by the k-th scan signal (SCANk) of the gate-on voltage (Von) supplied to the k-th scan line (Sk). The second switching transistor (ST2) is turned on by the k-th sensing signal (SENSk) of the gate-on voltage (Von) supplied to the k-th sensing signal line (SEk). During the second period (t2), the first switch (SW1) is turned off by the first switch control signal (SCS1) of the second logic level voltage (V2). The second switch (SW2) is turned on by the second switch control signal (SCS2) of the first logic level voltage (V1).

During the second period (t2), the reference voltage (VREF) is not supplied to the jth reference voltage line (Rj) due to the turn-off of the first switch (SW1). In addition, the reference voltage line (Rj) is connected to the analog-to-digital converter (140) due to the turn-on of the second switch (SW2) during the second period (t2). During the second period (t2), the sensing data voltage (SVdata) is supplied to the gate electrode of the driving transistor (DT) due to the turn-on of the first switching transistor (ST1). During the second period (t2), the source electrode of the driving transistor (DT) is connected to the analog-to-digital converter (140) through the jth reference voltage line (Rj) due to the turn-on of the second switching transistor (ST2).

During the second period (t2), since the voltage difference (Vgs=SVdata-VREF) between the gate electrode and the source electrode of the driving transistor (DT) is greater than the threshold voltage (Vth) of the driving transistor (DT), the driving transistor (DT) flows current.

The source voltage of the driving transistor (DT) rises to "VREF+α". α may vary depending on the threshold voltage of the driving transistor (DT), the electron mobility of the driving transistor (DT), or the degree of deterioration of the organic light emitting diode (OLED). Therefore, during the second period (t2), a voltage reflecting the threshold voltage of the driving transistor (DT), the electron mobility of the driving transistor (DT), or the degree of deterioration of the organic light emitting diode (OLED) is sensed at the source electrode of the driving transistor (DT).

Figure 7 is a graph showing the change in brightness of each organic light-emitting diode over time in an organic light-emitting display device according to the present application.

An organic light-emitting display device according to the present application includes first and second organic light-emitting diodes (OLED1, OLED2).

The first organic light emitting diode (OLED1) exhibits a decrease in luminance over time that is the same as when it degrades at a standard degradation rate, which is the degradation rate predicted by a standard OLED degradation model.

The second organic light emitting diode (OLED2) exhibits a decrease in luminance over time at a faster rate than the standard degradation rate, which is the degradation rate predicted by the standard OLED degradation model.

The second organic light emitting diode (OLED2) may be an organic light emitting diode (OLED) that is easily deteriorated due to a defect in the design or an internal organic light emitting layer, or is provided in an area on the display panel (10) that is used with higher brightness than other areas or is maintained in a turn-on state for a longer period of time and thus deteriorates quickly. After the first driving time (T1) has elapsed, the amount of brightness decrease (βL') due to deterioration of the second organic light emitting diode (OLED2) compared to the initial brightness (LV_INI) is greater than the amount of brightness decrease (βL) due to deterioration of the first organic light emitting diode (OLED1).

In general, due to process deviation of organic light emitting diodes (OLEDs), the deterioration rate of organic light emitting diodes is different for each display panel (10) and also for each area within the same display panel (10). Therefore, when deterioration compensation is performed by estimating the deterioration amount of multiple display panels (10) or multiple areas within one display panel (10) using a deterioration rate model expressed as one standard deterioration rate, a difference occurs between the deterioration amount estimated by the deterioration model and the actual deterioration amount of the display panel (10). When a difference in the deterioration amount occurs, a deterioration compensation error occurs, and an image sticking phenomenon occurs even after deterioration compensation.

In this application, the actual degradation level of an organic light emitting diode (OLED) is calculated by measuring the current flowing from a high potential power supply voltage (ELVDD), which is an electrical physical quantity, for each display panel (10), and for each area within the same display panel (10). After measuring the current flowing from each high potential power supply voltage (ELVDD) to the organic light emitting diode (OLED), a correction coefficient calculated from the measured current value is reflected in the degradation amount model, thereby calculating the degradation amount of the organic light emitting diode (OLED) for each area within the display panel (10). This application performs degradation compensation using the degradation amount for each area, and can prevent degradation compensation errors and afterimage phenomena due to differences in degradation speeds.

FIG. 8 is a graph showing the source voltage of a driving transistor (DT) of an organic light-emitting display device according to the present application and the current flowing to each organic light-emitting diode (OLED).

The I-V characteristic curves of a driving transistor (DT) and an organic light-emitting diode (OLED) are illustrated. In addition, the driving start point on the I-V characteristic curve and the method of determining the current according to the high-potential power supply voltage (ELVDD) are shown.

In display mode, the organic light emitting diode (OLED) is driven in the saturation region (SAT) of the driving transistor (DT). In the saturation region (SAT), a constant amount of current flows in the OLED even when there is a change in the high-potential power supply voltage (ELVDD). However, in the present application, the driving transistor (DT) is driven in the linear region (LIN) in order to measure the threshold voltage (Vth) of the driving transistor (DT), the electron mobility of the driving transistor (DT), or the degradation characteristics of the organic light emitting diode (OLED) in the sensing mode.

In the linear region (LIN) of the driving transistor (DT), if the magnitude of the threshold voltage (Vth) of the organic light-emitting diode (OLED) is different, the magnitude of the source voltage (V TFT) of the driving transistor (DT) becomes different.

For example, the magnitude of the first threshold voltage (Vth1) of the first organic light emitting diode (OLED1) may be smaller than the magnitude of the second threshold voltage (Vth1) of the second organic light emitting diode (OLED2). In this case, the magnitude of the first source voltage (VTFT1), which is the source voltage of the driving transistor (DT) connected to the first organic light emitting diode (OLED1), may be larger than the magnitude of the second source voltage (VTFT2), which is the source voltage of the driving transistor (DT) connected to the second organic light emitting diode (OLED2). In this case, the current flowing in the first organic light emitting diode (OLED) is greater than the current flowing in the second organic light emitting diode. In addition, it can be seen that the degree of deterioration of the second organic light emitting diode (OLED) is severe and thus the current flowing in the second organic light emitting diode (OLED) is reduced.

In order to drive the driving transistor (DT) in the linear region (LIN), in the sensing mode, a voltage lower than the high-potential power supply voltage (ELVDD) used to drive the organic light-emitting diode (OLED) in the display mode is supplied to the drain electrode of the driving transistor (DT).

FIG. 9 is a plan view showing a compensation circuit (200), a plurality of driving transistors (DT1 to DTk), and a plurality of organic light-emitting diodes (OLED1 to OLEDk) of an organic light-emitting display device according to the present application.

A compensation circuit (200) supplies a voltage lower than a high-potential power supply voltage (ELVDD) to a drain electrode of a driving transistor and measures the amount of deterioration of an organic light emitting diode (OLED) for each area within a display panel (10). A compensation circuit (200) according to the present application includes a first power supply voltage unit (ELVDD1), a second power supply voltage unit (ELVDD2), first and second control switches (SWC1, SWC2), an operational amplifier (210), and a feedback resistor (RF).

The first power voltage supply unit (ELVDD1) supplies a high-potential power voltage (ELVDD). The first power voltage supply unit (ELVDD1) may be a line connected to a power management integrated circuit (PMIC) to transmit a high-potential power voltage generated by the power management integrated circuit. The high-potential power voltage (ELVDD) is the same voltage as the high-potential power voltage (ELVDD) that drives the display panel (10) in a display mode. Accordingly, the first power voltage supply unit (ELVDD1) can drive a plurality of driving transistors (DT1 to DTk) and a plurality of organic light-emitting diodes (OLED1 to OKEDk) in the display mode.

The second power supply voltage unit (ELVDD2) supplies a sensing power supply voltage that is a voltage lower than the high-potential power supply voltage (ELVDD). The second power supply voltage unit (ELVDD2) is connected to a power management integrated circuit (PMIC) and can generate a sensing power supply voltage using one of the driving power voltages generated by the power management integrated circuit. The sensing power supply voltage is a voltage lower than the high-potential power supply voltage (ELVDD) and is a voltage that causes a plurality of driving transistors (DT1 to DTk) to operate in a linear region (LIN). Accordingly, the compensation circuit (200) can sense threshold voltages of the plurality of driving transistors (DT1 to DTk), electron mobility of the plurality of driving transistors (DT1 to DTk), or deterioration degrees of the plurality of organic light-emitting diodes (OLED1 to OKEDk) in the sensing mode.

A first control switch (SWC1) connects a first power voltage supply unit (ELVDD1) and a plurality of driving transistors (DT1 to DTk). The first control switch (SWC1) is turned on by a first light-emitting signal (EL1) so that the first power voltage supply unit (ELVDD1) can supply a high-potential power voltage (ELVDD) to the plurality of driving transistors (DT). The first control switch (SWC1) can be implemented with a P-type MOS transistor. However, the present invention is not limited thereto, and the first control switch (SWC1) can be implemented with a circuit element whose turn-on and turn-off can be controlled by a control signal.

The second control switch (SWC2) connects the second power voltage supply unit (ELVDD2) and the plurality of driving transistors (DT1 to DTk). The second control switch (SWC1) is turned on by the second light emission signal (EL2) so that the second power voltage supply unit (ELVDD2) can supply the sensing power voltage to the plurality of driving transistors (DT). The second control switch (SWC2) can be implemented with a P-type MOS transistor. However, the present invention is not limited thereto, and the second control switch (SWC2) can be implemented with a circuit element whose turn-on and turn-off can be controlled by a control signal.

The operational amplifier (210) can be implemented with a circuit element close to an ideal operational amplifier (OP-AMP). The positive input terminal of the operational amplifier (210) is connected to a second power supply voltage (ELVDD2). The negative input terminal of the operational amplifier (210) is connected to a second control switch (SWC2). The output terminal of the operational amplifier (210) is connected to an analog-to-digital converter (140).

The operational amplifier (210) has a characteristic of maintaining the voltages of the positive input terminal and the negative input terminal to be the same. Accordingly, the operational amplifier (210) can transmit the sensing power voltage supplied from the second power voltage supply unit (ELVDD2) to the second control switch (SWC2).

The feedback resistor (RF) is connected between the negative input terminal of the operational amplifier (210) and the output terminal of the operational amplifier (210). No current flows through the negative input terminal of the operational amplifier (210). Therefore, the negative input terminal and the output terminal of the operational amplifier (210) must be connected in a line so that the current can be fed back and transmitted to the analog-to-digital converter (140). The feedback resistor (RF) is placed on the line connecting the negative input terminal and the output terminal of the operational amplifier (210).

The compensation circuit (200) of the present application distinguishes between two types of driving power supplied to the display panel (10) according to the display mode and the sensing mode. In the display mode, a high-potential power supply (ELVDD) for driving to display an image of the display panel (10) is supplied. In the sensing mode, a sensing power supply voltage for measuring the amount of deterioration of an organic light emitting diode (OLED) is supplied.

Therefore, in the display mode, the first power voltage supply unit (ELVDD1) must be able to supply a high-potential power voltage (ELVDD), and in the sensing mode, the second power voltage supply unit (ELVDD2) must be able to supply a sensing power voltage lower than the high-potential power voltage (ELVDD). To this end, the first and second power voltage supply units (ELVDD1, ELVDD2) can be selectively connected to the display panel (10) through the first and second control switches (SWC1, SWC2).

When the sensing power supply voltage is supplied from the second power supply voltage supply unit (ELVDD2) to drive the driving transistor (DT) in the linear region (LIN), the compensation circuit (200) can measure the amount of deterioration of the organic light emitting diode (OLED). A predetermined current is measured in the compensation circuit (200) in response to the sensing power supply voltage. The measured current is calculated as a sensing voltage by a feedback resistor (RF) through an operational amplifier (210). The sensing voltage is converted into a digital value by an analog-to-digital converter (140). The sensing data (SD) converted into a digital value is used to calculate a deterioration compensation gain for correcting digital video data (DATA) into compensation digital video data (CDATA).

The compensation circuit (200) may be built into a power management integrated circuit. Alternatively, the compensation circuit (200) may be built into a source driver IC (21). Alternatively, the compensation circuit (200) may be composed of separate individual components and placed on a source printed circuit board (50).

Fig. 10 is a waveform diagram showing the operation of a compensation circuit (200) of an organic light-emitting display device according to the present application.

The organic light emitting display device according to the present application has a sensing mode (SEN) and a display mode (DIS) during operation. Since the first and second control switches (SWC1, SWC2) of the organic light emitting display device according to the present application are exemplified as P-type MOS transistors, they are turned off when a high logic level signal is input to the gate electrode, and are turned on when a low logic level signal is input to the gate electrode.

In the sensing mode (SEN), the first light emitting signal (EL1) maintains a high logic level to turn off the first control switch (SWC1). The second light emitting signal (EL2) maintains a low logic level to turn on the second control switch (SWC2). Accordingly, in the sensing mode (SEN), the drain electrode of the driving transistor (DT) is connected to the second power voltage supply unit (ELVDD2) to receive the sensing power voltage.

In the display mode (DIS), the first emission signal (EL1) maintains a low logic level to turn on the first control switch (SWC1). The second emission signal (EL2) maintains a high logic level to turn off the second control switch (SWC2). Accordingly, in the display mode (DIS), the drain electrode of the driving transistor (DT) is connected to the first power voltage supply unit (ELVDD1) to receive the high-potential power voltage (ELVDD).

The data voltage (Vdata) is input in sensing mode (SEN) and display mode (DIS) while repeating 1 frame period (1 frame) and blank period (BP) on the data lines (D1~Dm).

The ADC, which is the output data of the analog-to-digital converter (ADC), is output only in the blank period (BP) of the sensing mode (SEN), and is not output in the 1 frame period (1 frame) of the sensing mode (SEN) and the display mode (DIS).

In the sensing section (SEN) for measuring the amount of deterioration of an organic light emitting diode (OLED) of the present application, the first control switch (SWC1) is turned off and the second control switch (SWC2) is turned on. Accordingly, a sensing power voltage can be supplied to the display panel (10) in the sensing mode (SEN). Digital video data (DATA) is sequentially input one frame section (1 frame). After driving of each one frame section (1 frame), a current flowing in the second power voltage supply unit (ELVDD2) is measured through the analog-to-digital converter (140) in the blank section (BP).

After the measurement is completed, the sensing section (SEN) ends and the display mode (DIS) proceeds. In the display mode (DIS), the first control switch (SWC1) is turned on and the second control switch (SWC2) is turned off. Accordingly, a high-potential power supply voltage (ELVDD) can be supplied to the display panel (10) in the display mode (DIS).

The measurement and driving timing of the present application can be performed at the time when the user turns on the power of the organic light-emitting display device and the driving starts. Additionally, it can be performed during the driving of the organic light-emitting display device, or it can be performed at the time when the driving ends.

Fig. 11 is a plan view showing a compensation method of a display panel (10) of an organic light-emitting display device according to the present application.

Current measurement for estimating the amount of deterioration of an organic light emitting diode (OLED) according to the present application is performed on a display panel (10) by area. The entire display area (DA) of the display panel (10) is divided into a plurality of areas (a11 to anm) each having a width m (m is an integer greater than or equal to 2) and a height n (n is an integer greater than or equal to 2). Thereafter, the amount of deterioration is measured sequentially in the plurality of areas (a11 to anm). To this end, each of the plurality of areas (a11 to anm) is driven by sequentially supplying digital video data (DATA) having a constant grayscale. Digital video data (DATA) having a black grayscale is supplied to areas other than the measurement target area where the amount of deterioration is to be measured.

A sensing power supply voltage is applied so that a driving transistor (DT) provided in a measurement target area where the amount of deterioration is to be measured can operate in a linear area (LIN). At this time, the current flowing through the second power supply voltage supply unit (ELVDD2) is measured through a compensation circuit (200). By driving each of the multiple areas (a11 to anm) and measuring the current, a measured current value for each of the multiple areas (a11 to anm) can be secured.

Measurements are performed at the initial shipment of the display panel (10) to secure measurement current data for each display panel (10) and for each area within the display panel (10) before deterioration occurs in the organic light emitting diode (OLED). Meanwhile, when a user uses an organic light emitting display device according to the present application, current is measured while performing sensing work for each area of the display panel (10) at set times, for example, when the organic light emitting display device is turned on. The measured current value is compared with the measured current value secured at the initial shipment of the display panel (10), and the degree of deterioration of the organic light emitting diode (OLED) can be calculated from the difference in the current values.

FIG. 12 is a graph showing the relationship between changes in threshold voltage of an organic light-emitting display device according to the present application and deterioration of an organic light-emitting diode.

Even within a single display panel (10), deterioration of an organic light emitting diode (OLED) occurs differently for each area. In order to measure the deterioration amount of an organic light emitting diode (OLED), there is a change in a measured current value according to a sensing power voltage, and the threshold voltage change amount (ΔVth) can be calculated from the change in such measured current value. In addition, by using a luminance meter, the luminance change amount for each area of the display panel (10) can be measured, and the luminance deterioration amount (ΔL) can be calculated. As a result, the correlation between the threshold voltage change amount (ΔVth) and the luminance deterioration amount (ΔL) can be confirmed.

By using the correlation between the threshold voltage change amount (ΔVth) and the luminance deterioration amount (ΔL) obtained through prior measurement, a coefficient that can correct the deviation of the deterioration amount of the organic light emitting diode (OLED) for each area can be calculated from the threshold voltage change amount (ΔVth) measured for each area when the organic light emitting diode (OLED) is driven. The coefficient that can correct the deviation of the deterioration amount of the organic light emitting diode (OLED) is a value that reflects the difference in the degree of deterioration that occurs for each display panel (10) or for each area within the display panel (10). Therefore, the coefficient that can correct the deviation of the deterioration amount for each display panel (10) or for each area within the display panel (100) can be reflected in the standard deterioration amount model to calculate the deterioration amount.

The organic light-emitting display device and its driving method according to the present application have a corresponding deterioration model for each display panel or each area within one display panel. When deterioration compensation is performed using a model that corrects the deviation, deterioration compensation error due to a difference in deterioration speed due to process deviation of the organic light-emitting diode (OLED) and the resulting afterimage phenomenon can be prevented.

Although the organic light-emitting display device according to the present application has been described in detail with reference to the attached drawings, the present application is not necessarily limited to these examples, and various modifications may be implemented within a scope that does not deviate from the technical idea of the present application. Therefore, the protection scope of the present application should be interpreted by the claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present application.

10: Display panel 20: Data drive unit
21: Source driver IC 22: Flexible film
40: Gate driver 41: Scan signal output unit
42: Sensing signal output section 50: Source printed circuit board
60: Timing controller 70: External compensation circuit
80: Reference voltage generator 90: Control printed circuit board
91: Flexible Cable 140: Analog-to-digital converter
200: Compensation Circuit
ELVDD1, ELVDD2: First and second power supply voltages
SWC1, SWC2: First and second control switches
210: Operational Amplifier RF: Feedback Resistor

Claims (22)

A display panel including a plurality of pixels, each of the plurality of pixels including a driving transistor connected to a first power line, a first transistor, a second transistor, a capacitor connected to a gate electrode of the driving transistor, and an organic light-emitting diode connected to a second power line;
A scan signal output section providing a scan signal to the first transistor;
A sensing signal output section that provides a sensing signal to the second transistor; and
comprising a compensation circuit connected to the first power line;
The above compensation circuit,
In the display mode, the first power voltage is supplied to the first power line,
An organic light emitting display device, which supplies a second power voltage lower than the first power voltage to the first power line in a sensing mode and senses the current of the pixel through the first power line. In claim 1,
The above display panel includes a plurality of areas,
The above compensation circuit, in the sensing mode,
An organic light-emitting display device that operates the driving transistor in a linear region using the second power supply voltage, senses the current of the pixel in each of the plurality of regions through the driving transistor operating in the linear region, and generates and outputs a sensing voltage from the sensed current. delete In claim 1,
The above compensation circuit,
An organic light-emitting display device that senses the current of the pixel, which reflects the threshold voltage of the driving transistor or the amount of deterioration of the organic light-emitting diode. In claim 2,
The above sensing mode is,
a first period in which the source electrode of the driving transistor is initialized through the second transistor; and
An organic light emitting display device, comprising a second period in which a sensing data voltage is applied to a gate electrode of the driving transistor through the first transistor, and the current of the pixel is sensed by the compensation circuit through the driving transistor operating in the linear region and the first power line. In claim 2,
An analog-to-digital converter that converts the sensing voltage into sensing data and outputs it; and
An organic light emitting display device further comprising an external compensation circuit that calculates a compensation gain for compensating video data of each pixel based on the sensing data, and compensates for the video data by applying the calculated compensation gain. In claim 1,
a reference voltage line connected to the second transistor; and
An organic light emitting display device further comprising a reference voltage generating unit that supplies a reference voltage to the reference voltage line. In claim 1,
The above compensation circuit,
A first power voltage supply unit that supplies the first power voltage, which is a high-potential power voltage, to the first power line in the above display mode; and
An organic light emitting display device, comprising a second power voltage supply unit that supplies the second power voltage, which is a sensing power voltage, to the first power line in the sensing mode. In claim 8,
The above compensation circuit,
a first control switch switched to supply the high potential power voltage to the first power line in the above display mode; and
An organic light emitting display device further comprising a second control switch that is switched to supply the sensing power voltage to the first power line in the sensing mode. In claim 2,
The above compensation circuit, in the sensing mode,
An operational amplifier that receives the first power voltage through a first input terminal, supplies the first power voltage to the first power line through a second input terminal connected to the first power line, senses the current of the pixel flowing to the second input terminal through the first power line, and outputs the sensing voltage through an output terminal; and
An organic light emitting display device, comprising a feedback resistor connected between the second input terminal and the output terminal of the operational amplifier. In claim 2,
The above compensation circuit,
An organic light-emitting display device that senses a sensing current in which the deterioration amount of the organic light-emitting diode is reflected sequentially in each of the plurality of regions. In claim 6,
An organic light-emitting display device, wherein the analog-to-digital converter converts the sensing voltage into the sensing data and outputs it during a blank period in the sensing mode. A display panel including a plurality of pixels, each of the plurality of pixels including a driving transistor connected to a first power line, a first transistor, a second transistor, a capacitor connected to a gate electrode of the driving transistor, and an organic light-emitting diode connected to a second power line;
A scan signal output section providing a scan signal to the first transistor;
A sensing signal output section that provides a sensing signal to the second transistor; and
In relation to the measurement of the threshold voltage of the driving transistor and the deterioration characteristic of the organic light emitting diode, a compensation circuit is included which supplies a sensing power voltage to the driving transistor through the first power line in a sensing mode for operating the driving transistor in a linear region, senses the current of the pixel through the driving transistor operating in the linear region and the first power line, and generates and outputs a sensing voltage from the sensed current.
The above driving transistor is,
In the display mode, the high-potential power supply voltage supplied to the first power line is received and operates in the saturation region,
An organic light emitting display device, which operates in the linear region by the sensing power supply voltage supplied to the first power line in the sensing mode and which is lower than the high-potential power supply voltage. In claim 13,
The above display panel includes a plurality of areas,
An organic light-emitting display device in which the above compensation circuit senses the current of the pixel for each of the plurality of regions through the first power line. In claim 13,
The above compensation circuit,
An organic light-emitting display device that senses the current of the pixel, which reflects the threshold voltage of the driving transistor or the amount of deterioration of the organic light-emitting diode. In claim 13,
An analog-to-digital converter that converts the sensing voltage into sensing data and outputs it; and
An organic light emitting display device further comprising an external compensation circuit that calculates a compensation gain related to compensation of video data of each of the plurality of pixels based on the sensing data, and compensates for the video data using the calculated compensation gain. In claim 13,
a reference voltage line connected to the second transistor; and
An organic light emitting display device further comprising a reference voltage generating unit that supplies a reference voltage to the reference voltage line. In claim 14,
The above compensation circuit,
In the above display mode, a first power voltage supply unit supplying the high potential power voltage;
In the above sensing mode, a second power voltage supply unit supplying the sensing power voltage;
An operational amplifier that supplies the sensing power voltage supplied from the second power voltage supply unit to the first input terminal to the second input terminal connected to the first power line, and senses the current of the pixel flowing to the second input terminal through the first power line and outputs it as the sensing voltage;
A feedback resistor connected between the second input terminal and the output terminal of the above operational amplifier;
A first control switch for supplying the high-potential power voltage to the first power line in the above display mode; and
An organic light emitting display device comprising a second control switch that supplies the sensing power voltage from the operational amplifier to the first power line in the sensing mode. Comprising a plurality of pixels including an organic light-emitting diode and a driving transistor,
The above organic light emitting diode,
It includes an anode electrode connected to the source electrode of the driving transistor, a cathode electrode supplied with a low-potential power supply voltage lower than the first high-potential power supply voltage, and a light-emitting layer,
The above driving transistor is,
Based on the voltage difference between the gate electrode and the source electrode of the driving transistor, the current flowing from the power line to which the first high-potential power supply voltage is supplied is controlled to the organic light-emitting diode,
In the display mode, the first high-potential power supply voltage supplied to the first power line is supplied and operates in the saturation region,
An organic light emitting display device that operates in a linear region by receiving a second high-potential power voltage lower than a first high-potential power voltage supplied to the first power line in a sensing mode. In claim 19,
Each of the above plurality of pixels,
A first transistor connected to the gate electrode of the driving transistor and electrically connecting the data line and the gate electrode of the driving transistor based on a scan signal supplied to the first gate line;
A second transistor electrically connecting the source electrode of the driving transistor and the reference voltage line based on a sensing signal supplied to the second gate line, and connected to the source electrode of the driving transistor; and
An organic light-emitting display device further comprising a capacitor connected between the gate electrode and the source electrode of the driving transistor. delete delete

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