KR20220096041A - Light emitting display apparatus - Google Patents

Abstract

The purpose of the present invention is to provide a light emitting display apparatus capable of initializing data lines whenever light emitting elements are sensed. To this end, the light emitting display apparatus comprises: a light emitting display panel having pixels including light emitting elements; a data driver for supplying the data voltage to the data lines provided in the light emitting display panel during a display period in which an image is output from the light emitting display panel, and converting a sensing signal, transmitted through sensing lines provided in the light emitting display panel, into sensing data in a light emitting element sensing mode in which the light emitting elements are sensed; a control unit for storing the sensing data; a switching driver for connecting the data lines or the sensing lines to the data driver according to a switching driver control signal transmitted from the control unit; and an initialization unit for initializing the data lines between light emitting element sensing periods in the light emitting element sensing mode.

Description

Light-emitting display device {LIGHT EMITTING DISPLAY APPARATUS}

The present invention relates to a light emitting display device.

A light emitting display device is a display device that outputs light using a light emitting device, and includes a light emitting display panel provided with the light emitting device.

As the light emitting display device is continuously used, the light emitting devices deteriorate, and accordingly, the characteristics of the light emitting devices are changed, and thus the light emitting devices do not emit light normally.

In order to understand the degree of change in characteristics of the light emitting devices, sensing of the light emitting devices is being performed.

Sensing of the light emitting devices is sequentially performed for each gate line.

While sensing of the light emitting devices is sequentially performed for each gate line, charges may be charged in the data line by a leakage current generated during the sensing process, and accordingly, sensing of the light emitting devices may not be performed accurately. .

SUMMARY OF THE INVENTION An object of the present invention, which has been proposed to solve the above problems, is to provide a light emitting display device capable of initializing a data line whenever sensing of a light emitting device is performed.

According to an aspect of the present invention, there is provided a light emitting display device including a light emitting display panel including pixels including light emitting elements, and a light emitting display provided in the light emitting display panel during a display period in which an image is output from the light emitting display panel. A data driver that supplies a data voltage to a data line and converts a sensing signal transmitted through a sensing line provided in the light emitting display panel into sensing data in a light emitting device sensing mode in which sensing of the light emitting devices is performed; A control unit for storing sensing data, a switching driver for connecting the data line or the sensing line to the data driver according to a switching driver control signal transmitted from the control unit, and data between light emitting device sensing periods in the light emitting device sensing mode It includes an initializer that initializes the line.

According to the present invention, whenever sensing of the light emitting device is performed, the data line may be initialized. Accordingly, a sensing error due to charges charged in the data line during sensing of the light emitting device may be reduced.

Further, according to the present invention, since the sensing conditions for the light emitting devices provided at the upper end and the lower end of the light emitting display panel can be the same or similar, when sensing the light emitting devices, between the upper end and the lower end of the light emitting display panel No deviation occurs.

1 is an exemplary view showing the configuration of a light emitting display device according to the present invention.
2 is an exemplary view showing the structure of a pixel applied to a light emitting display device according to the present invention.
3 is an exemplary diagram illustrating a configuration of a gate driver applied to a light emitting display device according to the present invention.
4 is an exemplary view showing the configuration of a control unit applied to a light emitting display device according to the present invention.
5 is an exemplary view showing the structures of a data driver, an initialization unit, and a switching driver applied to a light emitting display device according to the present invention.
6 is an exemplary diagram illustrating waveforms of signals applied during a sensing period of a light emitting device of a light emitting display device according to the present invention;
7 to 9 are exemplary views for explaining a method in which the data driver, the switching driver, and the initialization unit shown in FIG. 5 are operated by the signals shown in FIG. 6;

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and those of ordinary skill in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the present invention is only defined by the scope of the claims.

In the present specification, in adding reference numbers to the components of each drawing, it should be noted that only the same components are given the same number as possible even though they are indicated on different drawings.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is construed as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between two parts unless 'directly' is used.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal relationship is described with 'after', 'following', 'after', 'before', etc. It may include cases that are not continuous unless this is used.

The term 'at least one' should be understood to include all possible combinations of one or more related items. For example, the meaning of 'at least one of the first item, the second item and the third item' means not only the first item, the second item, or the third item respectively, but also two of the first item, the second item and the third item. It means a combination of all items that can be presented from more than one.

Although the first, second, etc. are used to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each embodiment may be independently implemented with respect to each other or implemented together in a related relationship. may be

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

1 is an exemplary view showing the configuration of a light emitting display device according to the present invention, FIG. 2 is an exemplary view showing the structure of a pixel applied to a light emitting display device according to the present invention, and FIG. 3 is a light emitting display device according to the present invention It is an exemplary diagram showing the configuration of a gate driver applied to the , and FIG. 4 is an exemplary diagram showing the configuration of a control unit applied to a light emitting display device according to the present invention.

The light emitting display device according to the present invention can constitute various electronic devices. The electronic device may be, for example, a smartphone, a tablet PC, a TV, or a monitor.

A light emitting display device according to the present invention includes, as shown in FIGS. 1 to 4 , a light emitting display panel 100 including pixels 101 including light emitting devices ED, and a light emitting display panel 100 . In the display period in which an image is output, the data voltage Vdata is supplied to the data line DL provided in the light emitting display panel 100, and in the light emitting device sensing mode in which sensing of the light emitting devices ED is performed, light is emitted. A data driver 300 for converting a sensing signal transmitted through a sensing line SL provided in the display panel 100 into sensing data Sdata, a control unit 400 for storing the sensing data Sdata, a control unit ( According to the switching driver control signal transmitted from 400), the switching driver 500 connects the data line or the sensing line to the data driver 300 and is connected to the reference voltage supply unit 710 during the display period, and in the light emitting device sensing mode. and an initialization unit 600 that initializes a data line between sensing periods of the light emitting device.

First, the light emitting display panel 100 includes a display area 102 and a non-display area 103 . The display area 102 includes gate lines GL1 to GLg, data lines DL1 to DLd, sensing lines SL1 to SLd, and pixels 101 .

The pixel 101 provided in the light emitting display panel 100 includes, for example, as shown in FIG. 2 , the light emitting device ED, the first to fifth transistors Tsw1 to Tsw5, and the capacitor Cst. ) and a driving transistor Tdr. That is, the pixel 101 includes a pixel driving unit PDU and a light emitting unit, and the pixel driving unit PDU includes first transistors Tsw1 to fifth transistors Tsw5, a capacitor Cst, and a driving transistor Tdr. and the light emitting unit may include a light emitting device ED.

The light emitting device ED may include any one of an organic light emitting layer, an inorganic light emitting layer, and a quantum dot light emitting layer, or may include a stacked or mixed structure of an organic light emitting layer (or an inorganic light emitting layer) and a quantum dot light emitting layer.

In addition, the light emitting device ED may output light corresponding to any one of various colors such as red, green, and blue, or may output white light.

The first transistor Tsw1 constituting the pixel driver PDU is turned on or off by the gate signal VG supplied to the gate line GL, and the data voltage Vdata supplied through the data line DL. is supplied to the driving transistor Tdr when the first transistor Tsw1 is turned on. The first voltage VDD is supplied to the driving transistor Tdr and the light emitting device ED through the first voltage supply line PLA, and the second voltage VSS emits light through the second voltage supply line PLB. It is supplied to the element ED. The second transistor Tsw2 and the fifth transistor Tsw5 are turned on or off by the sensing control signal VS supplied through the sensing control line SCL. The third transistor Tsw3 and the fourth transistor Tsw4 are turned on or off by the emission signal EM supplied through the emission line EL. The reference voltage Vref or the sensing driving voltage Vsd may be supplied to the fifth transistor Tsw5 through the sensing line SL, and a sensing signal related to a characteristic change of the light emitting device ED is transmitted through the fifth transistor Tsw5. ) and the sensing line SL may be transmitted to the data driver 300 .

The pixel 101 applied to the present invention may have a structure as shown in FIG. 2 , but the present invention is not limited thereto. Hereinafter, a light emitting display device including pixels 101 having the structure shown in FIG. 2 will be described as an example of the present invention. The structure of the pixel 101 as shown in FIG. 2 will be described in more detail as follows.

Each of the pixels 101 includes a light emitting device ED and a pixel driver PDU.

The pixel driver PDU includes a first transistor Tsw1 including a first terminal connected to the data line DL and a gate connected to the gate line GL to which the gate signal VG is supplied, a first voltage A driving transistor Tdr including a first terminal connected to the supply line PLA, a capacitor Cst connected between the second terminal of the first transistor Tsw1 and the gate of the driving transistor Tdr, a driving A second transistor Tsw2 including a first terminal connected to the gate of the transistor Tdr, a second terminal connected to the second terminal of the driving transistor Tdr, and a gate connected to the sensing control line SCL ), a third transistor including a first terminal connected to the second terminal of the first transistor Tsw1 , a second terminal connected to the sensing line SL, and a gate connected to the emission line EL (Tsw3), the first terminal connected to the second terminal of the driving transistor Tdr, the second terminal connected to the first terminal of the light emitting device ED, and the gate connected to the emission line EL The fourth transistor Tsw4 including a first terminal connected to a first terminal of the light emitting device ED, a gate connected to the sensing control line SCL, and a second terminal connected to the sensing line SL and a fifth transistor Tsw5 including

In this case, in the light emitting display panel 100 , pixel regions including the pixels 101 are formed, and signal lines for supplying various signals to the pixel driver PDU provided in the pixel 101 are formed.

For example, in the light emitting display panel including the pixel 101 as shown in FIG. 2 , the signal lines are a gate line GL, a data line DL, an emission line EL, and a sensing control line SCL. ), a first voltage supply line PLA, a second voltage supply line PLB, and a sensing line SL.

In this case, the gate line GL and the data line DL are provided along different directions, the sensing line SL is provided along a first direction parallel to the data line DL, and the sensing line SL is It is connected to the fifth transistors Tsw5 of the pixels provided along the first direction.

For example, as shown in FIG. 1 , when the data line DL and the sensing line SL are provided along the first direction, that is, the vertical direction of the light emitting display panel 100 , the gate line GL may be provided along the second direction, that is, the horizontal direction of the light emitting display panel 100 . The first direction and the second direction may be perpendicular to, but not necessarily perpendicular to, and various angles may be formed.

In detail, the light emitting display panel 100 includes pixels 101 , gate lines GL1 to GLg supplying gate signals VG to the pixels 101 , and data voltages to the pixels 101 . It includes data lines DL1 to DLd for supplying the data and sensing lines SL1 to SLd connected to light emitting devices ED provided in the pixels 101 . In this case, each of the pixels 101 has a light emitting element ED and a first terminal connected to a first terminal of the light emitting element ED, a gate connected to a sensing control line SCL, and a second terminal includes a fifth transistor Tsw5 connected to the sensing line SL.

Next, the data driver 300 may be provided on a chip-on film attached to the light emitting display panel 100 , and may also be connected to a main board on which the control unit 400 is provided. In this case, the chip-on-film includes lines for electrically connecting the control unit 400 , the data driver 300 , and the light emitting display panel 100 , and for this purpose, the lines are connected to the main substrate and the light emitting display panel 100 . It is electrically connected to the pads provided in the . The main board is electrically connected to an external board on which an external system is mounted.

The data driver 300 may be directly mounted on the light emitting display panel 100 and then electrically connected to the main board.

However, the data driver 300 may be formed as a single integrated circuit together with the controller 400 , and the integrated circuit may be provided on a chip-on-film or directly mounted on the light emitting display panel 100 .

The data driver 300 receives a sensing signal related to a characteristic change of the light emitting device ED provided in the light emitting display panel from the light emitting display panel, converts it into sensing data Sdata, and then transmits the sensed data Sdata to the controller 400 ) can be transmitted.

Next, the gate driver 200 may be configured as an integrated circuit and then mounted on the non-display area 103 , using a gate in panel (GIP) method in the non-display area 103 . It can also be directly embedded. When the gate-in-panel method is used, the transistors constituting the gate driver 200 may be provided in the non-display area 103 through the same process as the transistors provided in each pixel 101 of the display area 102 . can

When the gate pulse generated by the gate driver 200 is supplied to the gate of the first transistor Tsw1 provided in the pixel 101 , the first transistor Tsw1 is turned on. When the gate-off signal is supplied to the first transistor Tsw1, the first transistor Tsw1 is turned off. The gate signal VG supplied to the gate line GL includes a gate pulse and a gate-off signal.

As shown in FIG. 3 , the gate driver 200 may include stages 201 that supply gate signals VG to the gate lines GL1 to GLg connected to the pixels 101 .

Each of the stages 201 may include a plurality of transistors, and various types of clocks and voltages may be supplied to each of the stages 201 .

The gate driver 200 may include stages 201 that supply sensing control signals VS to sensing control lines SCL connected to the fifth transistors Tsw5 .

In this case, each of the stages 201 includes, in addition to the gate signal VG supplied to the gate lines GL1 to GLg, various signals as shown in FIG. 2 , for example, a sensing control signal VS and An emission signal EM may be further generated.

For example, each of the stages 201 may generate all of a gate signal VG, a sensing control signal VS, and an emission signal EM. The gate signal VG may be sequentially supplied to the gate lines GL1 to GLg, the sensing control signal VG may be sequentially supplied to the sensing control lines SCL, and the emission signal EM may be They may be sequentially supplied to the emission lines EL.

However, the stages 201 generating the gate signal VG, the sensing control signal VS, and the emission signal EM may be configured independently. That is, one stage 201 may generate at least one of a gate signal VG, a sensing control signal VS, and an emission signal EM.

That is, the gate signal VG, the sensing control signal VS, and the emission signal EM supplied to one pixel 101 may be generated in one stage 201 or at least two stages 201 . ) can also be created from

Signals as described above may be generated in various forms through currently known configurations and functions of gate drivers. Accordingly, a description of the specific structure of the stage 201 for generating the signals as described above will be omitted.

Next, the control unit 400 rearranges the input image data Ri, Gi, Bi transmitted from the external system by using the timing synchronization signal TSS transmitted from the external system, and then rearranges the rearranged image data Data. A data alignment unit 430 for supplying to the data driver 300, a control signal generation unit 420 for generating a gate control signal GCS and a data control signal DCS using the timing synchronization signal TSS; An input unit 410 for receiving the timing synchronization signal TSS and input image data Ri, Gi, Bi transmitted from an external system and transmitting the received to the data alignment unit 430 and the control signal generation unit 420, and For outputting the image data Data generated by the data alignment unit 430 and the control signals DCS and GCS generated by the control signal generation unit 420 to the data driver 300 or the gate driver 200 , It may include an output unit 440 .

The control unit 400 may perform a function of storing the sensing data Sdata transmitted from the data driver 300 , and for this purpose, the control unit 400 may include a storage unit 450 . However, the storage unit 450 may be provided in the light emitting display device as an independent component.

The control signal generator 420 may generate a control signal (hereinafter, simply referred to as a switching driver control signal) for controlling the switching driver 500 , and a control signal (hereinafter, referred to as a switching driver control signal) for controlling the initialization unit 600 . It is also possible to simply generate an initialization control signal).

Next, the external system performs a function of driving the control unit 400 and the electronic device. That is, when the electronic device is a smart phone, the external system receives various types of voice information, image information, and text information through a wireless communication network, and transmits the received image information to the controller 400 . The image information may be input image data Ri, Gi, Bi.

Next, the power supply 800 uses the power supplied from the outside, the gate signal VG, the sensing control signal VS, the emission signal EM, the data voltage Vdata, the reference voltage Vref, and the sensing. Voltages applied to the generation of the driving voltage may be generated. That is, the power supply unit 800 performs a function of supplying power to the gate driver 200 , the data driver 300 , and the control unit 400 .

Next, the switching driver 500 performs a function of connecting the data line DL or the sensing line SL to the data driver 300 according to the switching driver control signal transmitted from the controller 400 .

The switching driver 500 may be provided in the data driver 300 , or may be provided independently of the data driver 300 .

When the switching driver 500 is an independent component, the switching driver 500 may be provided in the non-display area 103 as shown in FIG. 1 , and in particular, an area in which the data driver 300 is provided. can be provided in In the following description, a light emitting display device including an independently provided switching driver 500 will be described as an example of the present invention.

A specific configuration and function of the switching driver 500 will be described below with reference to FIG. 5 .

Finally, the initialization unit 600 is connected to the reference voltage supply unit 710 during the display period when an image is output through the light emitting display panel 100 . The initialization unit 600 initializes the data line DL between light emitting device sensing periods in the light emitting device sensing mode.

The light emitting device sensing mode may be performed when the light emitting display device is turned on or off.

In the light emitting device sensing period, characteristics of the light emitting devices ED, for example, a threshold voltage are sensed, and in the light emitting device sensing mode, the light emitting device sensing periods are repeated.

A specific configuration and function of the initialization unit 600 will be described below with reference to FIG. 5 .

5 is an exemplary diagram illustrating the structures of a data driver, an initialization unit, and a switching driver applied to a light emitting display device according to the present invention.

As described above, the data driver 300 supplies a data voltage to the data line DL provided in the light emitting display panel 100 and connects the sensing line SL provided in the light emitting display panel 100 . It performs a function of converting a sensing signal transmitted through the sensing data into sensing data Sdata, and the sensing data Sdata is transmitted to the control unit 400 .

The switching driver 500 connects the data line DL or the sensing line SL to the data driver 300 according to the switching driver control signals 521 and 511 transmitted from the controller 400 .

The initialization unit 600 initializes the data line between the light emitting device sensing periods in the light emitting device sensing mode.

In order to perform the functions as described above, the data driver 300 , the switching driver 500 , and the initialization unit 600 may be configured as shown in FIG. 5 .

First, the data driver 300 includes a data voltage generator 320 that generates a data voltage Vdata to be transmitted to the data line DL, and a sensing drive that transmits a sensing driving voltage Vsd to the sensing line SL. The voltage transmitter 310, the converter 330 and the switching driver 500 for converting the sensing signal transmitted through the sensing line SL into sensing data Sdata and transmitting it to the controller 400 are used as a data voltage generator 320 , and a data switching unit 340 connected to any one of the sensing driving voltage transmitting unit 310 and the converting unit 330 .

The sensing driving voltage transmitter 310 may directly generate and output the sensing driving voltage Vsd using the power supplied from the power supply 800 , or the sensing driving voltage Vsd supplied from the power supply 800 . ) can also be printed.

The data voltage generator 320 converts the digital image data DATA transmitted from the controller 400 into an analog data voltage Vdata and outputs it. The data voltage generator 320 may be a data driver currently generally used to convert the image data DATA into the data voltage Vdata. Therefore, a detailed description of the data voltage generator 320 will be omitted. do.

The conversion unit 330 converts the sensing signal transmitted through the sensing line SL into sensing data Sdata and transmits the converted signal to the control unit 400 . To this end, the converter 330 may include an analog-to-digital converter capable of converting an analog sensing signal into digital sensing data Sdata.

In addition, in order to accurately control the operation timing of the converter 330 , the data voltage generator 320 , and the sensing driving voltage transmitter 310 , the converter 330 , the data voltage generator 320 , and the sensing driving voltage A switch may be provided in each of the transmitter 310 , and the switches provided in the converter 330 , the data voltage generator 320 , and the sensing driving voltage transmitter 310 control data transmitted from the controller 400 . It can be controlled by the signal DCS.

The data control signal DCS may include various control signals for controlling operation timings of the sensing driving voltage transmitter 310 , the data voltage generator 320 , and the converter 330 .

The data switching unit 340 connects the switching driver 500 to any one of the data voltage generating unit 320 , the sensing driving voltage transmitting unit 310 , and the converting unit 330 .

To this end, the data switching unit 340 is connected to the switching driver 500 through one line (hereinafter simply referred to as a connection line CL), and a first switching control signal ( SS1), the second switching control signal SS2 and the third switching control signal SS3, the sensing driving voltage transmitting unit 310, the data voltage generating unit 320, and the converting unit 330 connecting the connection line CL ) can be connected to any of the

The first to third switching control signals SS1 to SS3 are also one of the data control signals DCS generated by the controller 400 .

The data switching unit 340 includes a first switch 341 , a second switch 342 , and a third switch 343 .

The first switching control signal SS1 may control the first switch 341 connected between the sensing driving voltage transmitter 310 and the connection line CL, and the second switching control signal SS2 may generate a data voltage. The second switch 342 connected between the unit 320 and the connection line CL can be controlled, and the third switching control signal SS3 is a third connected between the converter 330 and the connection line CL. The switch 343 may be controlled.

The first switch 341 to the third switch 343 may be configured as transistors that are turned on or off in response to the first switching control signal SS1 to the third switching control signal SS3.

Second, the switching driver 500 includes a first switching unit 510 connecting the data line DL to the data driver 300 and a second switching unit connecting the sensing line SL to the data driver 300 ( 520).

The first switching unit 510 is connected between the data line DL and the connection line CL, and the second switching unit 520 is connected between the sensing line SL and the connection line CL.

When the sensing line SL is connected to the connection line CL by the second switching unit 520 , the data line DL is not connected to the connection line CL by the first switching unit 510 .

As shown in FIG. 5 , the first switching unit 510 has a first terminal connected to the connection line CL, a second terminal connected to the data line DL, and a gate connected to the first signal line 511 . ) can be a transistor connected to A first control signal DMUX is supplied to the first signal line 511 .

As shown in FIG. 5 , the second switching unit 520 has a first terminal connected to the connection line CL, a second terminal connected to the sensing line SL, and a gate connected to the second signal line 521 . ) can be a transistor connected to A second control signal SMUX is supplied to the second signal line 521 .

The switching driver control signal includes a first control signal DMUX and a second control signal SMUX.

The switching driver control signal may be generated by the control signal generator 420 of the controller 400 as described above.

One end of a capacitor may be connected to the data line DL for the purpose of preventing static electricity, and the other end of the capacitor may be connected to a line to which the second voltage VSS is supplied. Also, one end of the capacitor may be connected to the sensing line SL for the purpose of preventing static electricity, and the other end of the capacitor may be connected to a line to which the second voltage VSS is supplied.

As described above, when the sensing line SL is connected to the connection line CL by the second switching unit 520 , the data line DL is connected to the connection line CL by the first switching unit 510 . ) is not associated with

For example, in the light emitting device sensing mode, the light emitting device sensing period and the initialization period are generated alternately. In this case, in the light emitting device sensing period, when the second switching unit 520 is turned on and the sensing line SL is connected to the connection line CL by the second switching unit 520 , the first switching unit 510 . is turned off, and accordingly, the data line DL is not connected to the connection line CL.

However, in the initialization period IP generated between the light emitting device sensing periods, both the first switching unit 510 and the second switching unit 520 are turned on. In this case, since all of the first switches 341 to 343 provided in the data switching unit 340 are turned off, the data line DL and the sensing line SL are connected to the data driver 300 . not connected That is, in the initialization period generated in the light emitting device sensing mode, both the first switching unit 510 and the second switching unit 520 are turned on, but the switching driver 500 is not connected to the data driver 300 .

The light emitting device sensing period includes a charging period and a sensing period, as described below with reference to FIG. 6 .

During the charging period of the light emitting device sensing period, the second switching unit 520 is turned on and the first switching unit 510 is turned off, and the sensing driving voltage Vsd is supplied from the data driver 300 to the sensing line SL. .

During the sensing period of the light emitting device sensing period, the second switching unit 520 is turned on and the first switching unit 510 is turned off, and a sensing signal is supplied from the light emitting device EP to the data driver 300 .

When the initialization period starts after the sensing period has elapsed, the first switching unit 510 and the second switching unit 520 are turned on, and the data line is connected to the ground 720 through the initialization unit 600 . Accordingly, the data driver 300 is cut off from the switching driver 500 during the initialization period. That is, since all of the first switches 341 to 343 provided in the switching unit 340 are turned off during the initialization period, the data line DL and the sensing line ( DL) provided in the switching driver 500 are turned off. SL) is not connected to the data driver 300 .

Third, the initialization unit 600 is connected to the reference voltage supply unit 710 during a display period in which an image is output through the light emitting display panel 100 . Accordingly, the initialization unit 600 supplies the reference voltage Vref to the pixel 101 during the display period. For example, the gate of the driving transistor Tdr and the first terminal of the light emitting device ED may be initialized by the reference voltage Vref. That is, the reference voltage Vref may be used in a process of compensating for a change in the threshold voltage of the driving transistor Tdr during a display period in which an image is output through the light emitting display panel 100 .

The initialization unit 600 may perform a function of initializing the data line between the light emitting device sensing periods in the light emitting device sensing mode.

To this end, the initialization unit 600 includes a reference voltage switch 610 and an initialization switch 620 as shown in FIG. 5 .

The reference voltage switch 610 is connected to the reference voltage supply 710 during the display period under the control of the controller 400 , and is connected to the ground 720 in the light emitting device sensing mode. That is, the reference voltage switch 610 is continuously connected to the reference voltage supply unit 710 during the display period, and is continuously connected to the ground 720 in the light emitting device sensing mode. The reference voltage switch 610 is connected to the reference voltage supply unit 710 or the ground 720 according to the first initialization control signal SS4 transmitted from the control unit 400 .

The initialization switch 620 is connected between the reference voltage switch 710 and the data line DL, and is turned on or off according to the control of the controller 400 . The initialization switch 620 is turned on or off according to the second initialization control signal SS5 from the control unit 400 .

For example, in the light emitting device sensing mode, after the light emitting device sensing period for sensing the light emitting devices ED connected to the n-th gate line GLn provided in the light emitting display panel 100 elapses, when the initialization period starts , the initialization switch 720 is turned on, and the data line DL is connected to the ground 720 through the initialization unit 710 . As described above, the switching driver 500 is not connected to the data driver 300 during the initialization period.

After the initialization period has elapsed, when the light emitting device sensing period for sensing the light emitting devices ED connected to the n+1th gate line GLn+1 starts, the initialization switch 720 is turned off and the data line DL is turned off. This ground 720 is cut off.

In more detail, after the light emitting device sensing period for sensing the light emitting devices ED connected to the n-th gate line GL provided in the light emitting display panel 100 elapses and the initialization period starts, the data line DL ) is connected to the ground 720 through the initialization unit 600 . Accordingly, the data line DL may be initialized to the ground voltage.

After the initialization period has elapsed, when the light emitting device sensing period for sensing the light emitting devices ED connected to the n+1th gate line GLn+1 starts, the data line DL is cut off from the ground, and then, charging Period and sensing period are in progress.

6 is an exemplary diagram illustrating waveforms of signals applied during a sensing period of a light emitting device of a light emitting display device according to the present invention, and FIGS. 7 to 9 are the data driver, switching driver and initialization unit shown in FIG. 6 . It is an exemplary diagram for explaining a method operated by the signals.

First, FIG. 7 is an exemplary view for explaining how the data driver 300 and the switching driver 500 operate during the charging period P1 of the light emitting element sensing period EP2 for sensing a change in characteristics of the light emitting element. .

First, when the charging period P1 starts in the light emitting device sensing mode, the control unit 400 transmits the first switching control signal SS1 to connect the connection line CL to the sensing driving voltage transmitting unit 310 first. Transmits to the switch 341 , and transmits the third switching control signal SS3 for disconnecting the connection line CL from the converter 330 to the third switch 343 , and the connection line CL to the data voltage The second switching control signal SS2 to be disconnected from the generator 320 is transmitted to the second switch 342 .

Accordingly, the connection line CL and the sensing driving voltage transmitter 310 are connected through the first switch 341 .

Next, the control unit 400 transmits the first control signal DMUX and the second control signal SMUX to the first signal line so that the first switching unit 510 is turned off and the second switching unit 520 is turned on. 511 and the second signal line 521 .

Accordingly, the sensing line SL is connected to the connection line CL through the second switching unit 520 , and the data line DL is not connected to the connection line CL through the first switching unit 510 . does not

Through the above-described processes, the sensing line SL is connected to the sensing driving voltage transmission unit 310 .

Next, as the sensing line SL is connected to the sensing driving voltage transmitting unit 310 , the sensing driving voltage Vsd is supplied from the sensing driving voltage transmitting unit 310 to the pixel through the sensing line SL.

In this case, since the fifth transistor Tsw5 is turned on by the sensing control signal VS, the sensing driving voltage Vsd transmitted to the sensing line SL is transmitted to the light emitting device ED through the fifth transistor Tsw5. is applied to the first terminal of In addition, since the first transistor Tsw1, the third transistor Tsw3, and the fourth transistor Tsw4 are turned off by the gate signal VG having a high level and the emission signal EM having a high level, The first voltage VDD is not applied to the light emitting device ED.

Finally, by the sensing driving voltage Vsd applied to the first terminal of the light emitting device ED, the voltage VED of the first terminal of the light emitting device ED during the charging period P1 is shown in FIG. 6 . increases as shown, and accordingly, charges are charged in the first terminal of the light emitting device ED.

That is, in the charging period P1 , the light emitting device ED is charged by the sensing driving voltage Vsd applied to the light emitting device ED through the sensing line SL.

During the charging period P1, the reference voltage switch 610 is connected to the ground 720, and the initialization switch 620 is turned off. Accordingly, the data line DL is not connected to the ground 720 .

Second, FIG. 8 is an exemplary diagram for explaining how the data driver 300 and the switching driver 500 are operated in the sensing period P2 of the light emitting element sensing period EP for sensing the characteristic change of the light emitting element. .

First, while the sensing period P2 is in progress, the fifth transistor Tsw5 maintains a turned-on state, and the first transistor Tsw1, the third transistor Tsw3, and the fourth transistor Tsw4 are turned off. keep

When the sensing period P2 starts, the control unit 400 transmits the first switching control signal SS1 for disconnecting the connection line CL from the sensing driving voltage transmitting unit 310 to the data switching unit 340 and , transmits a second switching control signal SS2 for disconnecting the connection line CL from the data voltage generator 320 to the second switch 342 , and the controller 400 converts the connection line CL to the converter A third switching control signal SS3 to be connected to 330 is transmitted to the third switch 343 .

Accordingly, the connection line CL and the converter 330 are connected through the third switch 343 .

Next, the control unit 400 transmits the first control signal DMUX and the second control signal SMUX to the first signal line so that the first switching unit 510 is turned off and the second switching unit 520 is turned on. 511 and the second signal line 521 are continuously transmitted.

Accordingly, the sensing line SL is connected to the connection line CL through the second switching unit 520 .

Through the above-described processes, the sensing line SL is connected to the converter 330 .

Next, since the sensing line SL is connected to the converter 330 , and the fifth transistor Tsw5 is turned on by the sensing control signal VS, charges charged in the first terminal of the light emitting device ED are discharged to the converter 330 through the sensing line SL.

Accordingly, the voltage VED of the first terminal of the light emitting device ED decreases as shown in FIG. 6 in the sensing period P2.

Finally, when a preset period has elapsed since the sensing line SL is connected to the converter 330 by the third switching control signal SS3, the converter 330 senses the sensing line SL through the sensing line SL. The signal is converted into sensing data Sdata, and the generated sensing data Sdata is transmitted to the control unit 400 . The sensing signal may be a voltage applied to the first terminal of the light emitting device ED. For example, in FIG. 6 , the sensing signal indicated by A is converted into sensing data between the sensing period P2 and the initialization period. In detail, when a sensing signal is supplied for a preset period through the sensing line SL, the connection line CL, and the third switch 343 in the sensing period P2, the converter 330 converts the analog digital The converter is connected to the third switch 343 , and the sensing signal A supplied through the third switch 343 is converted into sensing data Sdata.

That is, the level of the threshold voltage of the light emitting device ED is changed according to the degree of deterioration of the light emitting device ED, and when the level of the threshold voltage of the light emitting device ED is changed, through the light emitting device ED for a preset period The amount of leaked charge changes, and the amount of leaked charge is proportional to the voltage.

Accordingly, the magnitude of the characteristic change of the light emitting device ED, for example, the variation amount of the threshold voltage of the light emitting device, may be determined by measuring the magnitude of the voltage sensed by the converter 330 . For example, the magnitude of the sensing signal A converted into sensing data varies according to the degree of deterioration of the light emitting device ED.

Accordingly, the input unit 410 of the control unit 400 may sense the change amount of the threshold voltage of the light emitting device ED by analyzing the sensing data Sdata transmitted from the converting unit 330 , and accordingly, the light emitting device The degree of deterioration of (ED) can be grasped.

The amount of change in the threshold voltage calculated by the input unit 410 may be stored in the storage unit 450 .

In the sensing period P2, the reference voltage switch 610 is connected to the ground 720, and the initialization switch 620 is turned off. Accordingly, the data line DL is not connected to the ground 720 .

Changes in threshold voltages of the light emitting devices ED connected to the n-th gate line GLn may be sensed by the charging period P1 and the sensing period P2 as described above.

In this case, the operation of converting the sensing signal A into the sensing data Sdata may be performed in the data driver 300 during the initialization period IP to be described later, and the sensing signal A is converted into the sensing data Sdata. After conversion to , an initialization period (IP) may be performed.

When the amount of change in threshold voltages of the light emitting devices ED connected to the n-th gate line GLn is sensed through the sensing period IP as described above, the initialization period IP starts.

Third, FIG. 9 shows a method of operating the data driver 300 , the switching driver 500 and the initialization unit 600 in the initialization period IP after the sensing period P2 for sensing the characteristic change of the light emitting device has elapsed. It is an example diagram to explain.

When the initialization period IP starts, as shown in FIG. 9 , the initialization switch 620 is turned on and the data line DL is connected to the ground 720 through the initialization unit 600 . That is, since the reference voltage switch 610 is connected to the ground 720 in the light emitting device sensing mode, when the initialization switch 620 is turned on during the initialization period IP, the data line DL is connected to the initialization switch 620 . and the ground 720 through the reference voltage switch 610 .

For example, between the light emitting device sensing periods ESP, that is, in the initialization period IP, as shown in FIG. 9 , the first transistor Tsw1 is turned on by the gate signal VG having a low level. The data line DL is connected to the initialization unit 600 through the switching driver 500 , and the initialization unit 600 is connected to the ground 710 . In addition, since the sensing control signal VS and the emission signal EM have a low level as shown in FIG. 6 , the second transistor Tsw2 , the fifth transistor Tsw5 , and the third transistor Tsw3 . and the fourth transistor Tsw4 is also turned on.

In addition, the first switching unit 510 and the second switching unit 520 are also turned on by the first control signal DMUX and the second control signal SMUX. In this case, as described above, in the initialization period PI, the first switch 341 , the second switch 342 , and the third switch 343 constituting the data switching unit 340 are all turned off. do. Accordingly, the switching driver 500 is not connected to the data driver 300 .

In this case, since the first switching unit 510 and the second switching unit 520 are turned on, and the first transistor Tsw1 and the third transistor Tsw3 connected to the data line DL are turned on, the light emitting device sensing Charges charged in the data line during the period ESP are transferred through the first switching unit 510 , the second switching unit 520 , the initialization switch 620 and the reference voltage switch 610 in the initialization period IP. It is discharged to ground 720 .

Accordingly, before the new light emitting device sensing period ESP starts, the data line DL may be initialized to the ground voltage.

In addition, since the sensing line SL may also be connected to the ground 720 through the initialization switch 620 and the reference voltage switch 610 , in the initialization period, the sensing line SL may also be initialized to the ground voltage.

When the sensing process for the light emitting devices ED connected to the nth gate line GLn and the initialization process for the data line DL and the sensing line SL are performed through the above processes, the nth + The light emitting device sensing period ESP for sensing the light emitting devices connected to the first gate line GLn+1 starts anew. In this case, the initialization switch 620 is turned off so that the data line DL and the sensing line SL are cut off from the ground.

Thereafter, the charging period P1, the sensing period P2, and the initialization period IP as described above proceed again.

That is, whenever the light emitting device sensing period ESP for the light emitting devices ED connected to one gate line GL is newly started through the above-described processes, the data line DL and the sensing line SL ), the data line DL and the sensing line SL may be initialized to the ground voltage.

Accordingly, while the sensing process of the light emitting devices ED connected to the nth gate line GLn is performed, charges charged in the data line DL and the sensing line SL are transferred to the n+1th gate line. The sensing signal generated when the sensing process for the light emitting devices ED connected to (GLn+1) is performed is not affected.

Accordingly, accurate sensing of the light emitting devices ED may be performed for each gate line.

In addition, when the light emitting device sensing period ESP is performed at the upper end of the light emitting display panel 100 , for example, at the upper end of the light emitting display panel 100 shown in FIG. 1 , and at the lower end of the light emitting display panel 100 . When the light emitting device sensing period ESP is performed, since the data line DL and the sensing line SL are initialized to the ground voltage, the sensing process at the lower end of the light emitting display panel 100 is performed in the light emitting display panel 100 . It can be performed under the same conditions as the sensing process at the upper end of the Accordingly, when sensing the light emitting devices, there is no deviation between the upper end and the lower end of the light emitting display panel 100 .

When the light emitting device sensing mode as described above ends and the light emitting display device is converted to the display mode to output an image, that is, during the display period, the control unit 400 controls the threshold voltage stored in the storage unit 450 . The input image data may be converted into image data DATA in consideration of the amount of change, the magnitude of the first voltage VDD may be varied in consideration of the amount of change in the threshold voltage, and the reference voltage ( Vref) can be varied.

That is, the amount of change in the threshold voltage of the light emitting device ED determined through the above-described processes may be applied to various types of compensation methods performed when an image is output from the light emitting display panel 100 .

For example, in a display period in which an image is output from the light emitting display panel, in order to compensate for a characteristic change due to deterioration of the driving transistor Tdr provided in the pixel 101 , a compensation for changing the size of the image data DATA (hereinafter simply referred to as external compensation) may be performed. In addition, in the display period, the threshold voltage of the driving transistor is adjusted to the luminance of the light emitting device in order to prevent a characteristic change (eg, a change in threshold voltage) due to deterioration of the driving transistor Tdr from affecting the luminance of the light emitting device. Compensation (hereinafter simply referred to as internal compensation) may be performed so as not to affect the .

However, when the threshold voltage of the light emitting device ED is changed due to deterioration of the light emitting device ED, if external compensation or internal compensation is performed without considering the amount of change in the threshold voltage of the light emitting device, luminance exactly corresponding to the data voltage cannot occur

Therefore, when external compensation or internal compensation is performed, the controller 400 considers the amount of change in the characteristics of the light emitting device ED calculated through the above-described processes (eg, the amount of change in threshold voltage), Perfect external compensation or internal compensation can be performed, and accordingly, the quality of the light emitting display device can be improved.

The compensation method performed using the amount of change in the characteristics of the light emitting device ED calculated according to the present invention (eg, the amount of change in threshold voltage) may be variously changed according to the characteristics and functions of the light emitting display device, and such compensation The method may be one of various compensation methods currently being used. In addition, the compensation methods as described above are not essential features of the present invention. That is, the present invention is used to calculate the amount of change in characteristics of the light emitting device ED that can be applied to the above compensation methods. Accordingly, detailed descriptions of specific methods of the above compensation methods will be omitted.

In this case, the above-described processes for calculating the amount of change in the characteristics of the light emitting device ED may be automatically performed every preset period when the light emitting display device is used by a user, or repair of the light emitting display device may be performed. It may be carried out in the process of forcing, or it may be carried out in the process of manufacturing the light emitting display device.

For example, when the light emitting display device is used by a user, the processes as described with reference to FIGS. 6 to 9 may be performed every week, or every month, or every year, or every 1000 hours. In addition, the amount of change in characteristics of the light emitting device calculated by the above processes may be stored in the storage unit 450 .

In this case, the above processes may be performed when the light emitting display device is turned on or off according to the control of the controller 400 or the control of an external system. Thereafter, when the light emitting display device is driven, the control unit 400 may perform internal compensation or external compensation using the amount of change in the characteristics of the light emitting device stored in the storage unit 450 . Accordingly, the image quality of the light emitting display device can be maintained continuously.

As another example, in the process for repairing the light emitting display device or the manufacturing process of the light emitting display device, the processes as described with reference to FIGS. 6 to 9 may be performed, and the light emitting device calculated by the above processes The amount of change in characteristics of may be stored in the storage unit 450 . Then, when the light emitting display device is driven by the user, the control unit 400 may perform internal compensation or external compensation using the amount of change in the characteristics of the light emitting device stored in the storage unit 450 , and accordingly, the light emitting display device image quality can be continuously maintained.

That is, it is determined that the processes as described with reference to FIGS. 6 to 9 need to be performed, so that the user, the repairer, or the manufacturer operates the control unit 400 in the light emitting device sensing mode, or the control unit 400 If it is automatically driven for a preset period, the controller 400 may perform the processes as described with reference to FIGS. 6 to 9 .

Those skilled in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential characteristics thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

100: light emitting display panel 200: gate driver
300: data driver 400: control unit
500: switching driver 600: initialization unit
800: power supply

Claims (12)

a light emitting display panel having pixels including light emitting elements;
During a display period in which an image is output from the light emitting display panel, a data voltage is supplied to a data line provided in the light emitting display panel, and in the light emitting device sensing mode in which sensing of the light emitting devices is performed, a data driver that converts the sensing signal transmitted through the sensing line into sensing data;
a control unit for storing the sensed data;
a switching driver connecting the data line or the sensing line to the data driver according to a switching driver control signal transmitted from the controller; and
and an initialization unit configured to initialize a data line between light emitting element sensing periods in the light emitting element sensing mode. The method of claim 1,
The initialization unit,
a reference voltage switch connected to the reference voltage supply unit during the display period under the control of the controller and connected to the ground in the light emitting device sensing mode; and
and an initialization switch connected between the reference voltage switch and the data line, the initialization switch being turned on or off according to the control of the controller. 3. The method of claim 2,
After the light emitting device sensing period for sensing the light emitting devices connected to the n-th gate line provided in the light emitting display panel elapses and the initialization period starts, the initialization switch is turned on and the data line is connected to the ground through the initialization unit. ,
When a light emitting device sensing period for sensing the light emitting devices connected to the n+1th gate line starts, the initialization switch is turned off to cut off the data line from the ground. The method of claim 1,
After the light emitting device sensing period for sensing the light emitting devices connected to the n-th gate line provided in the light emitting display panel elapses and the initialization period starts, the data line is connected to the ground through the initialization unit,
When the light emitting device sensing period for sensing the light emitting devices connected to the n+1th gate line starts, the data line is cut off from the ground. The method of claim 1,
The data driver is
a data voltage generator generating a data voltage to be transmitted to the data line;
a sensing driving voltage transmission unit for transmitting a sensing driving voltage to the sensing line;
a conversion unit converting the sensing signal transmitted through the sensing line into sensing data and transmitting it to the control unit; and
and a switching unit connecting the switching driver to any one of the data voltage generating unit, the sensing driving voltage transmitting unit, and the converting unit. The method of claim 1,
The switching driver is
a first switching unit connecting the data line to the data driver; and
and a second switching unit connecting the sensing line to the data driver. 7. The method of claim 6,
During the charging period of the light emitting device sensing period, the second switching unit is turned on and the first switching unit is turned off, so that a sensing driving voltage is supplied from the data driver to the sensing line;
In a sensing period of the light emitting device sensing period, the second switching unit is turned on and the first switching unit is turned off, so that a sensing signal is supplied from the light emitting device to the data driver,
When the initialization period starts after the sensing period has elapsed, the first switching unit and the second switching unit are turned on, and the data line is connected to a ground through the initialization unit. 8. The method of claim 7,
In the initialization period, the data driver is cut off from the switching driver. 8. The method of claim 7,
The initialization unit,
a reference voltage switch connected to the reference voltage supply unit during the display period under the control of the controller and connected to the ground in the light emitting device sensing mode; and
an initialization switch connected between the reference voltage switch and the data line and turned on or off according to the control of the controller;
The light emitting display device in which the initialization switch is turned on during the initialization period. 10. The method of claim 9,
When the initialization period elapses and a new light emitting device sensing period begins, the initialization switch is turned off. The method of claim 1,
Each of the pixels,
a first transistor including a first terminal connected to the data line and a gate connected to a gate line to which a gate signal is supplied;
a driving transistor including a first terminal connected to a first voltage supply line;
a capacitor connected between the second terminal of the first transistor and the gate of the driving transistor;
a second transistor including a first terminal connected to the gate of the driving transistor, a second terminal connected to a second terminal of the driving transistor, and a gate connected to a sensing control line;
a third transistor including a first terminal connected to the second terminal of the first transistor, a second terminal connected to the sensing line, and a gate connected to an emission line;
a fourth transistor including a first terminal connected to the second terminal of the driving transistor, a second terminal connected to the first terminal of the light emitting device, and a gate connected to the emission line; and
and a fifth transistor including a first terminal connected to the first terminal of the light emitting device, a gate connected to the sensing control line, and a second terminal connected to the sensing line. 12. The method of claim 11,
Between the sensing periods of the light emitting device, the first transistor is turned on, the data line is connected to the initialization unit through the switching unit driver, and the initialization unit is connected to a ground.

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