Light emitting display device and driving method thereof

Abstract

The present disclosure relates to a light emitting display apparatus and a driving method thereof. A light emitting display apparatus is provided, which includes a display panel including a plurality of sub-pixels connected to a reference line, and a data driver connected to a data line of the display panel. The data driver simultaneously acquires a deterioration information value regarding the plurality of sub-pixels through the data line after a driving transistor included in the plurality of sub-pixels performs a source follower operation by a reference voltage transmitted through the reference line and a data voltage for sensing transmitted through the data line.

Description

[0001] This application claims the benefit of Korean Patent Application No. 10-2021-0193351, filed on December 30, 2021, which is hereby incorporated herein by reference as if fully set forth herein. Technical Field

[0002] This invention relates to a light-emitting display device and its driving method. Background Technology

[0003] With the development of information technology, the market for display devices, which serve as a medium for users to connect with information, is expanding. Therefore, the use of display devices such as light-emitting diode (LED) devices, quantum dot (QDD) devices, and liquid crystal display (LCD) devices is increasing.

[0004] The display device mentioned above includes: a display panel including subpixels; a driver configured to output drive signals for driving the display panel; and a power supply configured to generate power to be supplied to the display panel or the driver.

[0005] When drive signals, such as scan signals and data signals, are supplied to subpixels formed on the display panel in the aforementioned display device, selected subpixels transmit light or emit light directly, and thus the display device can display an image. Summary of the Invention

[0006] Therefore, this disclosure relates to a light-emitting display device and its driving method that substantially eliminates one or more problems caused by the limitations and disadvantages of the prior art.

[0007] The purpose of this invention is to provide a light-emitting display device and a driving method thereof, which not only eliminates the need for a separate sensing line for acquiring degradation information values, but also acquires degradation information values ​​for at least three sub-pixels simultaneously while omitting the process of charging parasitic capacitors, thereby reducing the sensing time.

[0008] Other advantages, objects, and features of the invention will be set forth in part in the description which follows, and will become apparent to those skilled in the art upon review of the following, or may be learned from practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the written description and the claims herein, as well as in the accompanying drawings.

[0009] To achieve these and other advantages and according to the purposes of the invention, as implemented and broadly described herein, a light-emitting display device includes: a display panel comprising a plurality of sub-pixels connected to a reference line; and a data driver connected to a data line of the display panel, wherein the data driver, in which driving transistors in the plurality of sub-pixels perform a source-following operation via a reference voltage transmitted via the reference line and a data voltage for sensing transmitted via the data line, simultaneously acquires degradation information values ​​about the plurality of sub-pixels via the data line.

[0010] The data driver can estimate the degree of degradation of the driving transistors included in multiple sub-pixels after removing parasitic capacitance formed at the data line based on degradation information values ​​obtained through sensing operations via the data line and a pre-extracted lookup table.

[0011] A lookup table can be provided based on the following operation: driving multiple sub-pixels to cause charge sharing between capacitors included in the multiple sub-pixels and parasitic capacitors formed at the data lines, and repeatedly detecting the parasitic capacitance of the parasitic capacitors formed at the data lines while changing the reference voltage.

[0012] Each of the plurality of sub-pixels may further include: a capacitor having a first electrode connected to a gate electrode of a driving transistor and a second electrode connected to a second electrode of a driving transistor; an organic light-emitting diode having an anode connected to the second electrode of a driving transistor and a cathode connected to a second power line; a first switching transistor having a gate electrode connected to a first scan line, a first electrode connected to a corresponding data line in the data lines, and a second electrode connected to the gate electrode of a driving transistor; and a second switching transistor having a gate electrode connected to a second scan line, a first electrode connected to a reference line, and a second electrode connected to the anode of the organic light-emitting diode.

[0013] In another aspect of the present invention, a driving method for a light-emitting display device is provided, comprising: applying a reference voltage via a reference line connected to a plurality of sub-pixels of a display panel; applying a data voltage for sensing via a data line of the display panel by driving a data driver configured to drive the display panel; and simultaneously acquiring degradation information values ​​for the plurality of sub-pixels via the data line after a driving transistor included in the plurality of sub-pixels performs a source follower operation via the reference voltage transmitted via the reference line and the data voltage for sensing transmitted via the data line.

[0014] In another aspect of the present invention, a light-emitting display device is provided, comprising: a display panel including a plurality of sub-pixels connected to a reference line; and a data driver connected to a data line of the display panel, wherein the driving transistors included in the plurality of sub-pixels of the data driver perform a source follower operation by means of a reference voltage transmitted via the reference line and a data voltage for sensing transmitted via the data line, thereby changing the reference voltage and the data voltage for sensing such that the reference voltage and the data voltage for sensing are equal to each other, and then the data driver simultaneously acquires degradation information values ​​for the plurality of sub-pixels via the data line.

[0015] The data driver can simultaneously acquire degradation information values ​​for multiple sub-pixels based on a current-to-voltage converter configured to convert current to voltage and a digital-to-analog converter configured to convert digital signals to analog signals.

[0016] When the reference voltage and the data voltage used for sensing are changed to be equal to each other, the current-to-voltage converter and the digital-to-analog converter can operate as integrators and can obtain the current flowing through the data line as a degradation information value about multiple sub-pixels.

[0017] When the reference voltage and the data voltage used for sensing are changed to be equal to each other, the current-to-voltage converter and the digital-to-analog converter can operate as a current mirror and can acquire the current flowing through the data line as a degradation information value about multiple sub-pixels.

[0018] In another aspect of the invention, a driving method for a light-emitting display device is provided, comprising: applying a reference voltage via a reference line connected to a plurality of sub-pixels of a display panel; applying a sensing data voltage via a data line of the display panel by driving a data driver configured to drive the display panel; and after a driving transistor included in the plurality of sub-pixels performs a source follower operation via the reference voltage transmitted via the reference line and the sensing data voltage transmitted via the data line, changing the reference voltage and the sensing data voltage to make them equal to each other, and then simultaneously acquiring degradation information values ​​for the plurality of sub-pixels via the data line. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:

[0020] Figure 1 This is a schematic block diagram illustrating a light-emitting display device;

[0021] Figure 2 It is shown schematically. Figure 1 The diagram of the sub-pixels shown;

[0022] Figure 3 and Figure 4 This is a view illustrating the configuration of the gate-type scan driver within the panel;

[0023] Figure 5A and Figure 5B This is a view showing an example of the arrangement of gate-type scan drivers within the panel;

[0024] Figure 6 and Figure 7 This is a view illustrating a light-emitting display device according to a first embodiment of the present invention;

[0025] Figure 8 This is a simplified view illustrating the sub-pixels and data drivers according to a first embodiment of the present invention;

[0026] Figure 9 To show more specifically Figure 8 A view of a portion of the configuration of the data driver shown;

[0027] Figure 10 This is a driving waveform diagram illustrating the driving method of the light-emitting display device according to the first embodiment of the present invention;

[0028] Figures 11 to 14 This is a circuit diagram illustrating the time-based operation of the light-emitting display device according to a first embodiment of the present invention;

[0029] Figures 15 to 18 This is a circuit diagram illustrating the operation of a light-emitting display device modified according to a first embodiment of the present invention;

[0030] Figure 19 This is a circuit diagram that briefly illustrates the sub-pixel and data driver according to a second embodiment of the present invention;

[0031] Figure 20 To show more specifically Figure 19 The circuit diagram shown is a portion of the configuration of the data driver.

[0032] Figure 21 This is a driving waveform diagram illustrating the driving method of the light-emitting display device according to the second embodiment of the present invention; and

[0033] Figure 22 This is a circuit diagram illustrating the operation of the light-emitting display device according to a second embodiment of the present invention; and

[0034] Figures 23 to 26 This is a circuit diagram illustrating the configuration and operation of a DA converter according to a second embodiment of the present invention. Detailed Implementation

[0035] The display device according to exemplary embodiments of the present invention can be implemented as a television set, image player, personal computer (PC), home theater, automotive electronic device, smartphone, etc., but is not limited thereto. The display device according to exemplary embodiments of the present invention can be implemented as a light-emitting display (LED) device, a quantum dot display (QDD) device, a liquid crystal display (LCD) device, etc. However, for ease of description, the following description will be given in conjunction with, for example, a light-emitting display device configured to emit light directly based on inorganic light-emitting diodes or organic light-emitting diodes.

[0036] Figure 1 This is a schematic block diagram illustrating a light-emitting display device. Figure 2 It is shown schematically. Figure 1 The diagram shows the sub-pixels.

[0037] like Figure 1 and Figure 2 As shown, the light-emitting display device may include an image supplier 110, a timing controller 120, a scan driver 130, a data driver 140, a display panel 150, a power supply 180, etc.

[0038] Image supply 110 (a group or host system) can output various drive signals as well as image data signals supplied from external sources or stored in its internal memory. Image supply 110 can supply data signals and various drive signals to timing controller 120.

[0039] The timing controller 120 can output a gate timing control signal GDC for controlling the operating timing of the scan driver 130, a data timing control signal DDC for controlling the operating timing of the data driver 140, and various synchronization signals (vertical synchronization signal Vsync and horizontal synchronization signal Hsync), etc. The timing controller 120 can supply the data timing signal DDC to the data driver 140 and the data signal DATA supplied from the image supplier 110. The timing controller 120 can be in the form of an integrated circuit (IC) and therefore can be mounted on a printed circuit board, but is not limited thereto.

[0040] The scan driver 130 can output a scan signal (or scan voltage) in response to the gate timing control signal GDC supplied from the timing controller 120. The scan driver 130 can supply scan signals to the sub-pixels included in the display panel 150 through gate lines GL1 to GLm. The scan driver 130 can be in the form of an IC or can be directly formed on the display panel 150 as an in-panel gate, but is not limited thereto.

[0041] The data driver 140 can sample and latch the data signal DATA in response to the data timing control signal DDC supplied from the timing controller 120, convert the obtained digital data signal into an analog data voltage based on a gamma reference voltage, and output the data voltage. The data driver 140 outputs the data voltage to the sub-pixels included in the display panel 150 via data lines DL1 to DLn. The data driver 140 can be formed as an IC and therefore can be mounted on the display panel 150 or on a printed circuit board, but is not limited thereto.

[0042] Power supply 180 can generate a first power supply with a high-level voltage and a second power supply with a low-level voltage based on an external input voltage supplied from outside, and can output the first power supply and the second power supply through a first power line EVDD and a second power line EVSS. Power supply 180 can not only generate and output the first power supply and the second power supply, but also generate and output voltages required to drive scan driver 130 (e.g., gate voltage including gate high voltage and gate low voltage), voltages required to drive data driver 140 (drain voltage and drain voltage including half-drain voltage), etc.

[0043] The display panel 150 can display images in response to drive signals including scan signals and data voltages, first power, second power, etc. The sub-pixels of the display panel 150 can emit light directly. The display panel 150 can be manufactured based on a substrate with rigidity or ductility, such as glass, silicon, polyimide, etc. The light-emitting sub-pixels can be composed of red, green, and blue sub-pixels or red, green, blue, and white sub-pixels.

[0044] For example, a sub-pixel SP may include a pixel circuit connected to a first data line DL1, a first gate line GL1, a first power line EVDD, and a second power line EVSS, along with a switching transistor, a driving transistor, a capacitor, and an organic light-emitting diode (OLED). Sub-pixels SP used in light-emitting display devices have complex circuit configurations because they emit light directly. Furthermore, there are various compensation circuits configured not only to compensate for degradation of the OLED but also for degradation of the driving transistor, which is configured to supply drive current to the OLED. However, for ease of illustration, the sub-pixel SP is simply shown in block form.

[0045] Meanwhile, in the above description, the timing controller 120, scan driver 130, and data driver 140 have been described as having separate configurations. However, depending on the implementation type of the light-emitting display device, one or more of the timing controller 120, scan driver 130, and data driver 140 may be integrated into a single IC.

[0046] Figure 3 and Figure 4 This is a view illustrating the configuration of the gate-type scan driver within the panel. Figure 5A and Figure 5B This is a diagram showing an example of the arrangement of gate-type scan drivers within a panel.

[0047] like Figure 3 As shown, the in-panel gate-type scan driver, indicated by reference numeral "130", may include a shift register 131 and a level shifter 135. The level shifter 135 can generate a clock signal Clk and a start signal Vst based on signals and voltages output from a timing controller 120 and a power supply 180. The clock signal Clk can be generated with K different phases (K being an integer of 2 or greater), such as 2-phase, 4-phase, 8-phase, etc.

[0048] The shift register 131 can operate based on the signals Clk and Vst output from the level shifter 135, and can output scan signals Scan[1] to Scan[m] that enable or disable transistors formed on the display panel. The shift register 131 is formed on the display panel in the form of a thin film as an in-panel gate.

[0049] like Figure 3 and Figure 4 As shown, unlike shift register 131, level shifter 135 can be formed independently as an IC or can be internally included in power supply 180. However, this configuration is merely illustrative, and exemplary embodiments of the invention are not limited thereto.

[0050] like Figure 5A and Figure 5B As shown, in the in-panel gate-type scan driver, shift registers 131a and 131b that output scan signals can be located in the non-display area NA of the display panel 150. Shift registers 131a and 131b can be configured as follows: Figure 5A The settings shown are located in the left and right non-display areas NA of the display panel 150, or can be as follows: Figure 5B The arrangement shown is in the upper and lower non-display areas NA of the display panel 150. Meanwhile, although it is already in... Figure 5A and Figure 5B The shift registers 131a and 131b are shown and described as being located in the non-display area NA, but exemplary embodiments of the present invention are not limited thereto.

[0051] Figure 6 and Figure 7 This is a view illustrating a light-emitting display device according to a first embodiment of the present invention. Figure 8This is a simplified view illustrating the sub-pixels and data driver according to a first embodiment of the present invention. Figure 9 To show more specifically Figure 8 The view shown is a portion of the configuration of the data drive.

[0052] like Figure 6 As shown, multiple pixels can be disposed in the display area AA of the display panel 150. A pixel P may include a first sub-pixel SP1, a second sub-pixel SP2, a third sub-pixel SP3, and a fourth sub-pixel SP4. The first sub-pixel SP1 to the fourth sub-pixel SP4 can emit red light, white light, green light, and blue light, respectively. Of course, this configuration is only illustrative, and a pixel P can be composed of three sub-pixels configured to emit red light, green light, and blue light, respectively.

[0053] The first sub-pixel SP1, the second sub-pixel SP2, the third sub-pixel SP3, and the fourth sub-pixel SP4 can be independently connected to the first data line DL1, the second data line DL2, the third data line DL3, and the fourth data line DL4, respectively. The first sub-pixel SP1, the second sub-pixel SP2, the third sub-pixel SP3, and the fourth sub-pixel SP4 can be jointly connected to the reference line VREF.

[0054] Reference lines VREF can be arranged in multiples on the display panel 150. The reference lines VREF can be shared with all sub-pixels arranged on the display panel 150, and therefore can be arranged in a mesh configuration. The reference lines VREF can be electrically connected to the data driver 140 or a reference voltage source disposed on a separate substrate, and can transmit the reference voltage output from the reference voltage source. Therefore, the data driver 140 can have a reference voltage output channel for outputting the reference voltage.

[0055] Data driver 140 can be connected to display panel 150. Data driver 140 may include a first input / output channel DCH1, a second input / output channel DCH2, a third input / output channel DCH3, and a fourth input / output channel DCH4. The first input / output channel DCH1, the second input / output channel DCH2, the third input / output channel DCH3, and the fourth input / output channel DCH4 can be independently connected to the first data line DL1, the second data line DL2, the third data line DL3, and the fourth data line DL4, respectively.

[0056] The data driver 140 can simultaneously apply a sensing data voltage (hereinafter referred to as the sensing data voltage) to the first sub-pixel SP1, the second sub-pixel SP2, the third sub-pixel SP3, and the fourth sub-pixel SP4 via the first input / output channel DCH1 to the fourth input / output channel DCH4. Thereafter, as... Figure 7As shown, the data driver 140 can simultaneously acquire degradation information values ​​formed at the first sub-pixel SP1, the second sub-pixel SP2, the third sub-pixel SP3, and the fourth sub-pixel SP4 through the first input / output channel DCH1 to the fourth input / output channel DCH4.

[0057] The data driver 140 can simultaneously acquire degradation information values ​​formed at the first sub-pixel SP1, the second sub-pixel SP2, the third sub-pixel SP3, and the fourth sub-pixel SP4 (i.e., four sub-pixels). However, when a pixel consists of three sub-pixels, the data driver 140 can simultaneously acquire degradation information values ​​formed at all three sub-pixels. Furthermore, the data driver 140 can simultaneously acquire degradation information values ​​for all sub-pixels included in the display panel 150. In addition, the data driver 140 can group all data lines into multiple groups, such that each group includes multiple data lines, and can simultaneously acquire degradation information values ​​for sub-pixels based on the data line groups.

[0058] like Figure 8 As shown, a sub-pixel SP may include a first switching transistor TR1, a driving transistor DT, a second switching transistor TR2, a capacitor CST, and an organic light-emitting diode OLED.

[0059] The driving transistor DT can be connected at its gate electrode to one end of the capacitor CST, and at its first electrode to the first electric field line EVDD, and at its second electrode to the anode of the organic light-emitting diode (OLED) and the other end of the capacitor CST. The capacitor CST can be connected at one end (the first electrode) to the gate electrode of the driving transistor DT, and at its other end (the second electrode) to the anode of the OLED. The OLED can be connected at its anode to the second electrode of the driving transistor DT, and at its cathode to the second electric field line EVSS.

[0060] The first switching transistor TR1 can be connected at its gate electrode to the first scan line GL1a included in the first gate line GL1, and at its first electrode to the first data line DL1 and at its second electrode to the gate electrode of the driving transistor DT. The first switching transistor TR1 can be turned on in response to a first scan signal transmitted to it through the first scan line GL1a.

[0061] The second switching transistor TR2 can be connected at its gate electrode to the second scan line GL1b included in the first gate line GL1, while at its first electrode it is connected to the reference line VREF and at its second electrode it is connected to the anode of the organic light-emitting diode (OLED). The second switching transistor TR2 can be turned on in response to a second scan signal transmitted to it through the second scan line GL1b.

[0062] The data driver 140 may include a first switch SWA, a second switch SWB, a first driving circuit 141, a second driving circuit 145, etc. The data driver 140 can not only output sensing data voltage, display data voltage (hereinafter referred to as display data voltage), black data voltage, etc. through the first input / output channel DCH1, but also acquire degradation information values ​​formed at sub-pixel SP.

[0063] The first switch SWA can be connected to the first input / output channel DCH1 at its first electrode, to the first drive circuit 141 at its second electrode, and to a control circuit internally included in the data driver 140 at its control electrode. In response to a first switch control signal output from the control circuit, the first switch SWA can electrically connect the first drive circuit 141 to or disconnect it from the first input / output channel DCH1.

[0064] The second switch SWB can be connected to the first input / output channel DCH1 at its first electrode, to the second drive circuit 145 at its second electrode, and to the control circuit internally included in the data driver 140 at its control electrode. In response to a second switch control signal output from the control circuit, the second switch SWB can electrically connect the second drive circuit 145 to or disconnect it from the first input / output channel DCH1.

[0065] like Figure 9 As shown, the first driving circuit 141 may include a digital-to-analog converter (hereinafter referred to as a DA converter) DAC, which is configured to convert digital signals into analog signals (voltages) to output sensed data voltages, display data voltages, black data voltages, etc. Additionally, the second driving circuit 145 may include an analog-to-digital converter (hereinafter referred to as an AD converter) ADC, which is configured to convert analog signals (voltages) into digital signals to obtain degradation information values. Figure 9 In the figure, the reference numeral "Cd" can indicate the first parasitic capacitor formed at the first data line DL1, and the reference numeral "Cp" can indicate the second parasitic capacitor formed at the reference line VREF.

[0066] Figure 10 This is a driving waveform diagram illustrating the driving method of the light-emitting display device according to the first embodiment of the present invention. Figures 11 to 14 This is a circuit diagram illustrating the time-based operation of a light-emitting display device according to a first embodiment of the present invention.

[0067] like Figure 10As shown, the light-emitting display device according to the first embodiment of the present invention can be driven in the order of the first time period P1, the second time period P2, the third time period P3 and the fourth time period P4.

[0068] During the first time period P1 to the fourth time period P4, the first scan signal Scan1 can be applied in a logic high state. During the first time period P1 to the second time period P2, the first switch signal SWA can be applied in a logic high state. The second scan signal Scan2 can be applied in a logic high state only during the first time period P1 and the third time period P3. The second switch signal SWb can be applied in a logic high state only during the fourth time period P4.

[0069] like Figure 10 and Figure 11 As shown, during the first time period P1, the DA converter DAC can output a sensed data voltage. The sensed data voltage output from the DA converter DAC can be applied to the gate node GN through the turned-on first switch SWA and the turned-on first switching transistor TR1. Additionally, the sensed data voltage can be applied to the source node SN through the two ends of the capacitor CST. During the first time period P1, a reference voltage can be transferred to the reference line VREF. The reference voltage transferred from the reference line VREF can be applied to the source node SN through the turned-on second switching transistor TR2. Additionally, a reference voltage can be applied to the other end of the capacitor CST. As a result, the gate node GN and the source node SN, which are separated from each other by the reference capacitor CST, can be initialized.

[0070] like Figure 10 and Figure 12 During the second time period P2, the second switching transistor TR2 can be switched to the off state. As a result, the driving transistor DT can perform a source follower operation by applying the sensed data voltage to the gate node GN and the reference voltage to the source node SN. According to the source follower operation of the driving transistor DT, the voltage of the source node SN can rise to the level "Vdata-Vth". The level "Vdata-Vth" refers to the level obtained by subtracting the threshold voltage of the driving transistor DT from the sensed data voltage.

[0071] like Figure 10 and Figure 13As shown, during the third time period P3, the second switching transistor TR2 can switch to the on state. Because the second switching transistor TR2 is on, the reference voltage transmitted to the reference line VREF can be applied to the other end of the capacitor CST. As a result, the voltage at the source node SN of the driving transistor DT can rise to the reference voltage VREF. Furthermore, due to the influence of the voltage across the capacitor CST, the voltage at the gate node GN of the driving transistor DT can rise to the level "VREF+Vth". During the third time period P3, the first switch SWA can remain in the off state. Additionally, during the third time period P3, the DA converter DAC can maintain a high impedance state Hi-z, in which the DA converter DAC does not output any voltage, including the sensed data voltage.

[0072] like Figure 10 and Figure 14 As shown, during the fourth time period P4, the second switch SWB can be turned on, and the AD converter ADC can obtain the voltage "VREF+Vth" as a degradation information value through the first data line DL1. The AC converter ADC can convert the degradation information value, which has an analog form and is obtained through the first data line DL1, into sensing data in digital form, and can output the sensing data.

[0073] The sensing data output from the AD converter (ADC) can be used as a compensation value for estimating and compensating for the degradation of the drive transistor DT. Meanwhile, in order to estimate and compensate for the degradation of the drive transistor DT, only "Vth," which serves as the threshold voltage of the drive transistor DT, is used from "VREF" and "Vth" in "VREF+Vth," while "VREF," which serves as the reference voltage, is removed ("VREF" is removed through algorithmic and circuit processing, etc.).

[0074] Figures 15 to 18 This is a circuit diagram illustrating the operation of a light-emitting display device modified according to a first embodiment of the present invention.

[0075] In the light-emitting display device Figures 11 to 14 Under the condition of sequential operation, when the capacitance of the capacitor CST included in the sub-pixel is greater than the capacitance of the first parasitic capacitor Cd formed at the first data line DL1, the degraded information value may be incorrectly obtained due to the effect of charge sharing.

[0076] To address the problem of erroneously acquiring degradation information values ​​due to a first parasitic capacitor Cd formed at the data line, information about the parasitic capacitance formed at the data line can be pre-extracted in the form of a lookup table in a variant of the first embodiment of the present invention. Furthermore, the parasitic capacitance formed at the data line can be removed based on the degradation information value acquired through sensing operation and the pre-extracted lookup table, and thus a compensation value for estimating and compensating for the degree of degradation of the drive transistor DT can then be provided.

[0077] The lookup table extraction operation can be performed in the manner described below.

[0078] like Figure 15 As shown, a drive can be performed such that a capacitor CST included in the sub-pixel shares charge with a first parasitic capacitor Cd formed at the data line. For this purpose, the first switching transistor TR1 and the second switching transistor TR2 can be turned on, and a reference voltage can be applied to the reference line VREF.

[0079] like Figure 16 As shown, the first parasitic capacitance of the first parasitic capacitor Cd formed at the data line can be detected via the first node VN between the second switch SWB and the first switching transistor TR1. For this detection, the second switch SWB can be turned on, and the AD converter ADC can perform a sensing operation.

[0080] The above lookup table extraction operation can be performed in Figure 10 The process is performed before the fourth time period P4 (i.e., the sensing operation). For example, under the condition that the lookup table is extracted through the above process, when the reference voltage VREF[V] is 1V, the first node voltage VN[V], which can be "Cst / (Cst+Cd)", can be obtained. In addition, a lookup table can be provided that can estimate the first parasitic capacitance formed at the data line based on the first node voltage VN[V], i.e., "VN=Cst / (Cst+Cd)×VREF".

[0081] Meanwhile, the first parasitic capacitance formed at the data line or the second parasitic capacitance formed at the reference line VREF may exhibit fluctuations depending on the device's driving conditions, surrounding environmental conditions, etc. Therefore, to minimize such fluctuations, the reference voltage applied to the reference line VREF can be repeatedly changed. Figure 15 and Figure 16 The operation, and therefore, can provide the first parasitic capacitance of the first parasitic capacitor Cd as a lookup table.

[0082] After providing the lookup table through the aforementioned pre-operation, the first switching transistor TR1 and the second switching transistor TR2 can be turned on, and a reference voltage can be applied, thus allowing the lookup table to be retrieved for the reference voltage and the first node voltage.

[0083] Subsequently, the second switch SWB can be turned on while the first switching transistor TR1 and the second switching transistor TR2 are conducting. Then, degradation information values ​​can be obtained from the capacitor CST included in the sub-pixel and the first parasitic capacitor Cd formed at the data line. In this case, the obtained degradation information value, Vth, can be interpreted as being obtained from the first node VN to remove the first parasitic capacitance formed at the data line. This can be expressed as "VN = Cst / (Cst + Cd) x Vth".

[0084] Figure 19 This is a circuit diagram that briefly illustrates the sub-pixel and data driver according to a second embodiment of the present invention. Figure 20 To show more specifically Figure 19 The circuit diagram shown is a portion of the configuration of the data driver. Figure 21 This is a driving waveform diagram illustrating the driving method of the light-emitting display device according to the second embodiment of the present invention. Figures 23 to 26 This is a circuit diagram illustrating the configuration and operation of a DA converter according to a second embodiment of the present invention.

[0085] like Figure 19 As shown, a sub-pixel SP may include a first switching transistor TR1, a driving transistor DT, a second switching transistor TR2, a capacitor CST, and an organic light-emitting diode OLED.

[0086] The data driver 140 may include a first switch SWA, a second switch SWB, a first driving circuit 141, a second driving circuit 145, etc. The data driver 140 can not only output sensing data voltage, display data voltage, black data voltage, etc. through the first input / output channel DCH1, but also acquire degradation information values ​​formed at the sub-pixel SP.

[0087] The first switch SWA can be connected to the first input / output channel DCH1 at its first electrode, to the first drive circuit 141 at its second electrode, and to a control circuit internally included in the data driver 140 at its control electrode. In response to a first switch control signal output from the control circuit, the first switch SWA can electrically connect the first drive circuit 141 to or disconnect it from the first input / output channel DCH1.

[0088] The second switch SWB can be connected to the first drive circuit 141 at its first electrode, to the second drive circuit 145 at its second electrode, and to a control circuit internally included in the data driver 140 at its control electrode. In response to a second switch control signal output from the control circuit, the second switch SWB can electrically connect or disconnect the second drive circuit 145 from the first drive circuit 141. The second drive circuit 145 may include an AD converter (ADC) to convert degradation information values ​​in analog form into sensing data in digital form.

[0089] like Figure 20 As shown, the first drive circuit 141 may include a current-to-voltage converter (I / V converter) and a DA converter (DAC) configured to convert current into voltage, so as to not only output sensed data voltage, display data voltage, black data voltage, etc., but also acquire degradation information values.

[0090] Similar to the first embodiment of the present invention, in the second embodiment of the present invention, when the capacitance of the capacitor CST included in the sub-pixel is greater than the capacitance of the first parasitic capacitor Cd formed at the data line, the degradation information value may be incorrectly obtained due to the effect of charge sharing.

[0091] Similar to the first embodiment of the present invention, such as Figure 21 As shown, the light-emitting display device according to the second embodiment of the present invention can be driven in the order of the first time period P1, the second time period P2, the third time period P3 and the fourth time period P4.

[0092] However, in the second embodiment of the invention, the sensed data voltage and the reference voltage can be changed to be equal or approximately the same level during the third time period P3 to solve the problem of erroneously acquiring degraded information values ​​due to the first parasitic capacitor Cd formed at the data line. For this purpose, a first switching signal SWA can be applied in a logic high state during the period from the first time period P1 to the third time period P3. As a result, the voltage of the source node SN can rise, exhibiting a level change equal to or approximately the level change of the gate node GN.

[0093] like Figure 22As shown, the first switching transistor TR1, the second switching transistor TR2, and the first switch SWA can be in the ON state. For this reason, when the voltage of the source node SN rises to a level equal to or approximately equal to the level of the gate node GN, current can flow to the first node VN connected to the data line due to the voltage difference across the capacitor CST included in the sub-pixel. The I / V converter included in the first drive circuit 141 can detect the amount of current flowing through the data line as a degradation information value (ΔV = Vth) in order to extract the threshold voltage of the drive transistor DT.

[0094] like Figure 23 As shown, the first drive circuit 141 may include an I / V converter and a DA converter (DAC). The I / V converter and DA converter (DAC) included in the first drive circuit 141 can operate as current integrators when acquiring degradation information values.

[0095] like Figure 24 As shown, the driving mode of the first driving circuit 141 has been switched to the form of a current integrator. The first driving circuit 141 can instantly acquire the degradation information value (ΔV = Vth) stored in the capacitor CST included in the sub-pixel, and thus can eliminate the problem associated with the first parasitic capacitance of the first parasitic capacitor Cd formed at the data line and the second parasitic capacitance of the second parasitic capacitor Cp formed at the reference line.

[0096] like Figure 25 As shown, the I / V converter and DA converter DAC included in the first drive circuit 141 can operate in the form of a current mirror when acquiring degradation information values.

[0097] like Figure 26 As shown, the first driving circuit 141 has been switched to the form of a current mirror. The first driving circuit 141 can instantly acquire the degradation information value (ΔV = Vth) stored in the capacitor CST included in the sub-pixel, and thus can eliminate the problem associated with the first parasitic capacitance of the first parasitic capacitor Cd formed at the data line and the second parasitic capacitance of the second parasitic capacitor Cp formed at the reference line.

[0098] As is apparent from the above description, according to an exemplary embodiment of the present invention, degradation information values ​​of elements included in a sub-pixel can be acquired and compensated, and thus individual sensing lines can be removed. Furthermore, according to an exemplary embodiment of the present invention, the process of charging parasitic capacitors can be omitted, and degradation information values ​​for three sub-pixels can be acquired simultaneously, thus reducing sensing time.

[0099] The foregoing description and accompanying drawings have been presented to illustrate the technical concept of the invention. Those skilled in the art will understand that various modifications and variations are possible by combining, dividing, substituting, or changing the constituent elements without altering the essential characteristics of the invention. Therefore, the foregoing embodiments disclosed herein should be interpreted as illustrative only and not as limiting the principles and scope of the invention. It should be understood that the scope of the invention is defined by the appended claims, and all their equivalents fall within the scope of the invention.

Claims

1. A light-emitting display device, comprising: The display panel includes multiple sub-pixels connected to reference lines; as well as The data driver, which is connected to the data cable of the display panel, Wherein, after the driving transistors included in the plurality of sub-pixels perform source following operation via a reference voltage transmitted via the reference line and a data voltage for sensing transmitted via the data line, the data driver simultaneously acquires degradation information values ​​for the plurality of sub-pixels via the data line, wherein the data driver estimates the degree of degradation of the driving transistors included in the plurality of sub-pixels after removing parasitic capacitances formed at the data line based on the degradation information values ​​acquired through the sensing operation via the data line and a pre-extracted lookup table.

2. The light-emitting display device according to claim 1, wherein, The lookup table is provided based on the following operations: driving the plurality of sub-pixels such that charge sharing occurs between the capacitors included in the plurality of sub-pixels and the parasitic capacitors formed at the data lines, and repeatedly detecting the parasitic capacitance of the parasitic capacitors formed at the data lines while changing the reference voltage.

3. The light-emitting display device according to claim 1, wherein, Each of the plurality of sub-pixels also includes: A capacitor having a first electrode connected to the gate electrode of the driving transistor and a second electrode connected to the second electrode of the driving transistor; An organic light-emitting diode, the organic light-emitting diode having an anode connected to a second electrode of the driving transistor and a cathode connected to a second electric field line; A first switching transistor has a gate electrode connected to a first scan line, a first electrode connected to a corresponding data line in the data lines, and a second electrode connected to the gate electrode of the driving transistor; and The second switching transistor has a gate electrode connected to the second scan line, a first electrode connected to the reference line, and a second electrode connected to the anode of the organic light-emitting diode.

4. A driving method for a light-emitting display device, comprising: A reference voltage is applied by reference lines connected to multiple sub-pixels of the display panel; By driving a data driver configured to drive the display panel, a data voltage for sensing is applied via the data lines of the display panel; as well as After the driving transistors included in the plurality of sub-pixels perform source-following operation via the reference voltage transmitted via the reference line and the data voltage for sensing transmitted via the data line, degradation information values ​​about the plurality of sub-pixels are simultaneously acquired via the data line. The data driver estimates the degree of degradation of the driving transistors included in the plurality of sub-pixels after removing parasitic capacitances formed at the data lines based on degradation information values ​​obtained through sensing operations on the data lines and a pre-extracted lookup table.

5. A light-emitting display device, comprising: The display panel includes multiple sub-pixels connected to reference lines; as well as The data driver, which is connected to the data cable of the display panel, Specifically, the data driver, comprising driving transistors in the plurality of sub-pixels, performs a source-following operation using a reference voltage transmitted via the reference line and a sensing data voltage transmitted via the data line. It then changes the reference voltage and the sensing data voltage to make them equal, and subsequently, the data driver simultaneously acquires degradation information values ​​regarding the plurality of sub-pixels via the data line. The data driver estimates the degree of degradation of the driving transistors included in the plurality of sub-pixels after removing parasitic capacitances formed at the data lines based on degradation information values ​​obtained through sensing operations on the data lines and a pre-extracted lookup table.

6. The light-emitting display device according to claim 5, wherein, The data driver simultaneously acquires degradation information values ​​for the plurality of sub-pixels based on a current-to-voltage converter configured to convert current to voltage and a digital-to-analog converter configured to convert digital signals to analog signals.

7. The light-emitting display device according to claim 6, wherein, When the reference voltage and the data voltage used for sensing are changed to be equal to each other, the current-to-voltage converter and the digital-to-analog converter operate as integrators and acquire the current flowing through the data line as a degradation information value with respect to the plurality of sub-pixels.

8. The light-emitting display device according to claim 6, wherein, When the reference voltage and the data voltage used for sensing are changed to be equal to each other, the current-to-voltage converter and the digital-to-analog converter operate as a current mirror and acquire the current flowing through the data line as a degradation information value with respect to the plurality of sub-pixels.

9. A driving method for a light-emitting display device, comprising: A reference voltage is applied by reference lines connected to multiple sub-pixels of the display panel; By driving a data driver configured to drive the display panel, a data voltage for sensing is applied via the data lines of the display panel; as well as After the driving transistors included in the plurality of sub-pixels perform a source-following operation via the reference voltage transmitted via the reference line and the sensing data voltage transmitted via the data line, the reference voltage and the sensing data voltage are changed so that the reference voltage and the sensing data voltage are equal to each other, and then degradation information values ​​about the plurality of sub-pixels are simultaneously acquired via the data line. The data driver estimates the degree of degradation of the driving transistors included in the plurality of sub-pixels after removing parasitic capacitances formed at the data lines based on degradation information values ​​obtained through sensing operations on the data lines and a pre-extracted lookup table.

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