Electroluminescent display device and method for sensing electrical properties thereof

Abstract

The present disclosure relates to an electroluminescent display device and a method for sensing an electrical characteristic thereof, and the electroluminescent display device includes a display panel including a plurality of pixels including a sensing pixel and a non-sensing pixel connected to each data line, the plurality of pixels sharing one sensing line; a sensing circuit configured to sense an electrical characteristic value of the sensing pixel based on a sensing voltage applied to the shared sensing line; and a feedback unit configured to apply a feedback voltage according to the sensing voltage applied to the shared sensing line to a data line of the non-sensing pixel.

Description

[0001] This application claims the benefit of Korean Patent Application No. 10-2021-0194524, filed on December 31, 2021, which is incorporated herein by reference as if fully set forth herein. Technical Field

[0002] This disclosure relates to an electroluminescent display device and a method for sensing its electrical properties. Background Technology

[0003] An electroluminescent display device including an organic light-emitting diode (hereinafter referred to as OLED) has sub-pixels, each comprising OLEDs arranged in a matrix, and adjusts the brightness of the sub-pixels according to the grayscale of image data to display an image. Each sub-pixel includes a light-emitting element and a driving thin-film transistor (TFT) that controls the driving current input to the light-emitting element.

[0004] Subpixels in organic light-emitting diodes (OLEDs) exhibit a degradation characteristic where the threshold voltage changes over time. When the threshold voltage changes, a problem arises where image quality deteriorates even when the same data voltage Vdata is applied due to variations in the current flowing through the OLED. To address this issue, various methods for compensating for OLED degradation are being investigated.

[0005] The methods used to sense degradation can vary depending on the sub-pixel structure. Therefore, a method is needed that can effectively sense and compensate for degradation characteristics based on the sub-pixel structure. Summary of the Invention

[0006] One object of this disclosure is to provide an organic light-emitting display device and a method for sensing its electrical characteristics, wherein the organic light-emitting display device can prevent a decrease in the sensing accuracy of sensing pixels due to the parasitic capacitance of non-sensing pixels when multiple pixels share a sensing line.

[0007] To achieve these objectives and other advantages and for the purposes of this disclosure, as embodied and broadly described herein, an electroluminescent display device includes: a display panel comprising a plurality of pixels, the plurality of pixels including sensing pixels and non-sensing pixels connected to each data line, the plurality of pixels sharing a sensing line; a sensing circuit configured to sense electrical characteristic values ​​of the sensing pixels based on a sensing voltage applied to the shared sensing line; and a feedback unit configured to apply a feedback voltage based on the sensing voltage applied to the data line of the non-sensing pixels.

[0008] The feedback voltage can be a voltage value that minimizes the potential difference between the shared sensing line and the data line of the non-sensing pixel.

[0009] The electroluminescent display device may also include a data driver configured to provide a data voltage for sensing to a data line of a sensing pixel.

[0010] The feedback unit may include: an amplifier configured to receive a sensed voltage, apply a preset gain to the sensed voltage, and output the sensed voltage; and a feedback switch configured to connect the output line of the amplifier to the data line of a non-sensing pixel.

[0011] The amplifier may include: a non-inverting amplifier having a non-inverting input terminal connected to a shared sensing line and an inverting input terminal connected to a feedback line of an output terminal, the output terminal being connected to a data line of a non-sensing pixel; a first resistor connected to the inverting input terminal; and a second resistor connected to the feedback line.

[0012] The first resistor and the second resistor may include variable resistors.

[0013] The electroluminescent display device may further include a defective pixel determination unit configured to compare a sensed voltage with a preset reference voltage, and if the sensed voltage is equal to or greater than the reference voltage, to control a feedback voltage not to be applied to the data line of a non-sensing pixel.

[0014] The defect pixel determination unit may include: a non-inverting input terminal connected to a shared sensing line; an inverting input terminal to which a reference voltage is input; and a comparator configured to output a comparison result between the sensed voltage and the reference voltage.

[0015] The electroluminescent display device may also include a selector configured to apply a feedback voltage or a data voltage output from a data driver to a data line based on the determination result of the defective pixel determination unit.

[0016] The selector may include a multiplexer configured to output a feedback voltage to the data line of the non-sensing pixel if the sensed voltage is less than a reference voltage, and to apply a data voltage from the data driver to the data line if the sensed voltage is greater than the reference voltage.

[0017] The electrical characteristics of a sensing pixel may include the threshold voltage of the driving TFT of the sensing pixel.

[0018] In another aspect of this disclosure, a method for sensing electrical characteristics of an electroluminescent display device includes: providing a data voltage for sensing to a data line of a sensing pixel; applying a feedback voltage to a data line of a non-sensing pixel based on a sensing voltage applied to a shared sensing line; and sensing an electrical characteristic value of the sensing pixel based on the sensing voltage, wherein the electroluminescent display device includes a display panel having a plurality of pixels, the plurality of pixels including sensing pixels and non-sensing pixels connected to each data line, and the plurality of pixels sharing a sensing line.

[0019] The feedback voltage can be a voltage value that minimizes the potential difference between the shared sensing line and the data line of the non-sensing pixel.

[0020] The method may further include comparing a sensed voltage with a preset reference voltage, wherein applying a feedback voltage to a data line of a non-sensing pixel based on the sensed voltage applied to a shared sense line includes: if the sensed voltage is less than the reference voltage, then applying the feedback voltage to the data line of the non-sensing pixel.

[0021] The method may also include applying a data voltage output from the data driver to the data line if the sensed voltage is equal to or greater than the reference voltage.

[0022] In an electroluminescent display device according to an embodiment of the present disclosure, when multiple pixels share a single sensing line, a voltage having the same potential as the sensing line can be applied to the data line of a non-sensing pixel, thereby canceling out the potential difference between the sensing line and the data line of the non-sensing pixel, thus preventing the sensing accuracy of the sensing pixel from being reduced due to parasitic capacitance.

[0023] Those skilled in the art will understand that the effects achievable by this disclosure are not limited to those specifically described above, and that other advantages of this disclosure will become clearer from the following detailed embodiments. Attached Figure Description

[0024] Figure 1 This is a schematic block diagram of an electroluminescent display device according to an embodiment of the present disclosure.

[0025] Figure 2 It is formed in Figure 1 An example diagram of the unit pixel circuit in the display panel.

[0026] Figure 3 This is a block diagram schematically illustrating the compensation configuration of an electroluminescent display device according to an embodiment of the present disclosure.

[0027] Figure 4 This is a diagram illustrating the operation of sub-pixels during the sensing operation of an electroluminescent display device according to a comparative example.

[0028] Figure 5 It is shown Figure 4 A graph showing the control signal waveform and potential change waveform for each time period during the sensing operation.

[0029] Figure 6 This is a diagram illustrating the operation of sub-pixels during sensing operation of an electroluminescent display device according to an embodiment.

[0030] Figure 7 It is shown Figure 6 A graph showing the control signal waveform and potential change waveform for each time period during the sensing operation.

[0031] Figure 8 This is a diagram showing the equivalent circuit during sensing operation of the electroluminescent display device according to the first embodiment of the present disclosure.

[0032] Figure 9 This is a diagram showing the circuit of an electroluminescent display device according to a second embodiment of the present disclosure.

[0033] Figures 10 to 12 It is used for explanation Figure 9 A diagram showing the reference voltage setting method for the circuit.

[0034] Figure 13 This is a diagram showing the circuit of an electroluminescent display device according to a third embodiment of the present disclosure.

[0035] Figure 14 This is a graph showing the simulation results of an electroluminescent display device according to an embodiment of the present disclosure. Detailed Implementation

[0036] The advantages and features of this disclosure, and the ways in which they are implemented, will become apparent from the following detailed description of the embodiments, taken in conjunction with the accompanying drawings. However, this disclosure is not limited to the embodiments disclosed below and can be implemented in many different forms. Rather, these exemplary embodiments are provided to make this disclosure comprehensive and complete, and to fully convey the scope to those skilled in the art. Therefore, the scope of this disclosure should be defined by the claims.

[0037] The shapes, dimensions, scales, angles, quantities, etc., shown in the accompanying drawings to describe various embodiments of this disclosure are given by way of example only, and therefore, this disclosure is not limited to the illustrations in the drawings. Throughout the specification, identical or very similar elements are denoted by the same reference numerals. In this specification, when the terms "comprising," "including," etc., are used, other elements may be added unless the term "only" is used. Elements described in the singular are intended to include multiple elements unless the context clearly indicates otherwise.

[0038] In the interpretation of the constituent elements included in the various embodiments of this disclosure, even if not explicitly described, these constituent elements are to be interpreted as including a range of error.

[0039] In the description of various embodiments of this disclosure, when describing positional relationships, for example, when using terms such as "above," "over," "below," "side," etc. to describe the positional relationship between two parts, one or more other parts may be located between the two parts, unless the terms "direct" or "close" are used.

[0040] In the description of various embodiments of this disclosure, although terms such as "first" and "second" may be used to describe various elements, these terms are used only to distinguish elements that are the same or similar to each other. Therefore, in this specification, unless otherwise stated, within the technical scope of this disclosure, an element modified by "first" may be the same as an element modified by "second".

[0041] Throughout this specification, the same reference numerals will be used to refer to the same or similar parts.

[0042] In the following description, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description of the present disclosure, detailed descriptions of known functions and configurations included herein will be omitted where such descriptions might obscure the subject matter.

[0043] Figure 1 This is a schematic block diagram of an electroluminescent display device according to an embodiment of the present disclosure.

[0044] Reference Figure 1 An electroluminescent display device according to an embodiment of the present disclosure may include a display panel 10, a timing controller 11, a data driver 12, a gate driver 13, a sensing circuit 14, and a power supply circuit 15.

[0045] In the screen area of ​​the display panel 10 where the input image is displayed, data lines DL extending in the column direction (or vertical direction) and gate lines GL extending in the row direction (or horizontal direction) intersect, and unit pixels PXL are arranged in a matrix at the intersection to form a pixel array. Each data line DL is connected to an adjacent unit pixel in the column direction, and each gate line GL is connected to an adjacent unit pixel PXL in the row direction.

[0046] Each unit pixel PXL comprises multiple subpixels. Multiple subpixels can form a unit pixel PXL to create various color combinations. To simplify the pixel array, subpixels that make up the same unit pixel PXL can share the same sensing line SIO.

[0047] As subpixels degrade over time, the electrical characteristics of each subpixel, such as threshold voltage and electron mobility, change. These changes in electrical characteristics lead to brightness variations, necessitating the sensing and compensation of the electrical characteristics of each subpixel. Sensing lines (SIOs) are used to sense these subpixel characteristics. In a pixel array, the sensing lines (SIOs) can be positioned in a column direction parallel to the data lines (DLs), but are not limited to this.

[0048] The timing controller 11 receives timing signals such as the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the data enable signal DE, and the dot clock signal DCLK from the host system, and generates timing control signals for controlling the operating timing of the data driver 12 and the gate driver 13. The timing control signals may include a gate timing control signal GDC for controlling the operation of the gate driver 13 and a data timing control signal DDC for controlling the operation of the data driver 12.

[0049] The timing controller 11 receives image data DATA from the host system and sensing data Dsen, which includes the electrical characteristics of each sub-pixel, from the sensing circuit 14. The timing controller 11 can correct the image data DATA based on the sensing data Dsen and provide it to the data driver 12.

[0050] The timing controller 11 can temporarily separate display operations and sensing operations based on timing control signals DDC and GDC. The display operation is used to display image data DATA on the screen. The sensing operation is used to sense the electrical characteristics of pixel PXL.

[0051] The display operation can be performed during a vertically active period in which the data enable signal transitions between logic high and logic low levels within a frame, and the sensing operation can be performed during a vertically blank period within a frame that does not include the vertically active period. During the vertically blank period, the data enable signal remains at a logic low level. Simultaneously, the sensing operation can be performed during a power-on period from the application of system main power to the start of image reproduction, or during a power-off period from the end of image reproduction to the release of system main power. Furthermore, the sensing operation can be performed while the system power is applied and only the screen of the display device is turned off (e.g., in standby mode, sleep mode, low-power mode, etc.). When the sensing operation conditions are met according to a predetermined sensing process, the timing controller 11 can control the general operation of the sensing operation.

[0052] The data driver 12 is connected to the sub-pixel via the data line DL. The data driver 12 generates the data voltage required for the display or sensing operation of the sub-pixel according to the data timing control signal DDC, and provides the data voltage to the data line DL. The data voltage used for display operation is the result of digital-to-analog conversion of the image data DATA; therefore, the data driver 12 may include multiple digital-to-analog converters (hereinafter referred to as DACs).

[0053] Gate driver 13 is connected to the sub-pixel via gate line GL. Gate driver 13 generates a scan signal based on gate timing control signal GDC and provides the scan signal to gate line 15 according to the data voltage supply timing. The horizontal display line to be supplied with data voltage is selected by the scan signal.

[0054] Gate driver 13 generates a scan signal for display operation and provides the scan signal to gate line 15 according to the supply timing of the data voltage for display. Gate driver 13 can also generate a scan signal for sensing operation and provide the scan signal to gate line 15 according to the supply timing of the data voltage for sensing.

[0055] Gate driver 13 may include multiple gate driver integrated circuits, each including a gate shift register, a level shifter for converting the output signal of the gate shift register into a swing width for scan-on voltage and scan-off voltage, and an output buffer. Alternatively, gate driver 13 may be formed directly on the substrate of display panel 10 in an in-board gate driver (GIP) structure. In the case of GIP structure, the level shifter may be mounted on a control printed circuit board, and the gate shift register may be formed in the bezel area that is a non-display area of ​​display panel 10. The gate shift register includes multiple scan output stages (hereinafter referred to as GIP elements) connected in a cascaded manner. The GIP elements are independently connected to gate line GL to output scan signals to gate line GL.

[0056] Sensing circuit 14 is connected to unit pixel PXL of display panel 10 via readout line SIO. Sensing circuit 14 detects the voltage of readout line SIO, which changes during sensing operation due to the current flowing through the sub-pixel, and converts the detected voltage value into a digital signal to generate sensing data Dsen. Sensing circuit 14 then transmits the sensing data Dsen to timing controller 11.

[0057] The power supply circuit 15 generates the high-level drive voltage EVDD and low-level drive voltage EVSS required for the display and sensing operations of the sub-pixel. The power supply circuit 15 also generates the initialization voltage required for the sensing operation of the sub-pixel. During sensing operations, the power supply circuit 15 can generate the base voltage VPRES used to initialize the sensing line SIO.

[0058] Figure 2 This is a diagram illustrating the connection configuration of a unit pixel UNIT PXL according to an embodiment of this specification.

[0059] Reference Figure 2 The unit pixel PXL may include four sub-pixels SP1, SP2, SP3, and SP4 sharing a readout line SIO. The four sub-pixels SP1, SP2, SP3, and SP4 may be R (red), G (green), B (blue), and W (white) sub-pixels. Each of the sub-pixels SP1, SP2, SP3, and SP4 may include, for example, an organic light-emitting device (OLED), a driving element DT, switching elements ST1 and ST2, and a storage capacitor Cst.

[0060] The OLED emits light according to the drive current supplied from the driving element DT. The OLED emits light only during display operation and not during sensing operation. The anode of the OLED is connected to the second node N2, and its cathode is connected to the input terminal of the low-level drive voltage EVSS.

[0061] The driving element DT generates a driving current for display based on the gate-source voltage (i.e., the voltage difference between the data voltage Vdata supplied to the data line DL and the reference voltage) and provides the driving current to the OLED. The gate electrode of the driving element DT is connected to the first node N1, its drain electrode is connected to the input terminal of the high-level driving voltage EVDD, and its source electrode is connected to the second node N2.

[0062] A first switching element ST1 is connected between the data line DL and the first node N1, and is turned on according to the scan signal SCAN from the gate line GL. When the first switching element ST1 is turned on during sensing operation, the data voltage Vdata for sensing is applied to the first node N1. The gate electrode of the first switching element ST1 is connected to the gate line GL, its source electrode is connected to the data line DL, and its drain electrode is connected to the first node N1.

[0063] The second switching element ST2 is connected between the read line SIO and the second node N2, and is turned on according to the scan signal SCAN from the gate line GL. The second switching element ST2 is turned on during the initialization period of the sensing operation, applying the base voltage charged in the read line SIO to the second node N2, and remains on during the detection period after the initialization period to change the voltage of the read line SIO by the voltage of the second node N2. The gate electrode of the second switching element ST2 is connected to the gate line GL, its drain electrode is connected to the second node N2, and its source electrode is connected to the read line SIO.

[0064] The storage capacitor Cst is connected between the first node N1 and the second node N2, and stores the gate-source voltage of the driving element DT.

[0065] Figure 2 This is a simplified equivalent diagram of the circuit configuration for each sub-pixel SP. In reality, the driving circuitry for driving the organic light-emitting diode (OLED) in each sub-pixel SP may include one or more transistors in addition to the driving transistor DT and the storage capacitor Cst, and in some cases, may also include one or more capacitors.

[0066] Meanwhile, the driving transistor DT in each sub-pixel SP may degrade over time, thus altering its electrical characteristics, such as the threshold voltage Vth. Therefore, the electroluminescent display device according to this embodiment can provide a compensation function for sensing the electrical characteristics of the sub-pixel SP and compensating for brightness deviations based on the sensed electrical characteristics.

[0067] Figure 3 A compensation configuration for an electroluminescent display device according to an embodiment of the present disclosure is shown.

[0068] Reference Figure 3 The compensation configuration in the electroluminescent display device includes a data driver 12, a sensing circuit 14, and a compensator 30.

[0069] The data driver 12 generates the data voltage Vdata required for sensing operation and provides it to the data line DL. For this purpose, the data driver 12 may include multiple DACs.

[0070] Sensing circuit 14 is connected to unit pixel PXL of display panel 10 via readout line SIO. Sensing circuit 14 detects the voltage of sensing line SIO, which changes during sensing operation due to the current flowing through sub-pixel SP, and converts the detected voltage value into a digital signal to generate sensing data Dsen. For this purpose, sensing circuit 14 may include an analog-to-digital converter (hereinafter referred to as ADC) and a sampling switch SAM. Sampling switch SAM is turned on during the sampling period to connect the readout line (SIO) and ADC. ADC can be electrically connected to the sensing node of each sub-pixel SP via readout line SIO. ADC converts the sensing voltage Vsen input via readout line SIO into a digital value to generate sensing data Dsen.

[0071] The compensator 30 can determine the amount of data compensation for each sub-pixel SP based on the received sensing data Dsen. The compensator 30 can output compensation data Data' by reflecting the amount of data compensation in the data to be provided to the sub-pixel SP. The compensator 30 can be included in the timing controller 11.

[0072] Figure 4 and Figure 5 This is a diagram illustrating a method for sensing the electrical characteristics of an electroluminescent display device according to a comparative example, and Figure 6 and Figure 7 This is a diagram illustrating a method for sensing the electrical characteristics of an electroluminescent display device according to an embodiment.

[0073] In both the comparative example and the implementation, a display panel with one unit pixel corresponding to a readout line SIO is designated as the target. The unit pixel UNIT PXL may include four sub-pixels sharing the readout line SIO. The four sub-pixels may be R (red), W (white), G (green), and B (blue) sub-pixels. The four sub-pixels share one readout line SIO and one gate line GL. The four sub-pixels are connected to the R data line DL_R providing R data, the W data line DL_W providing W data, the G data line DL_G providing G data, and the B data line DL_B providing B data. Therefore, the four sub-pixels independently receive data via data lines DL_R, DL_W, DL_G, and DL_B, and independently sense the electrical characteristics of the four sub-pixels for each color during sensing operation. When a pixel of one color among the four sub-pixels becomes the sensing target, pixels of other colors become non-sensing targets. Pixels to be sensed are sensed pixels, and pixels without sensed pixels are non-sensing pixels. In the following text, as an example, we assume that the W sub-pixel is a sensing pixel and the remaining pixels (R, G, and B pixels) are non-sensing pixels.

[0074] Figure 4 and Figure 5 This is a diagram illustrating a method for sensing the electrical characteristics of an electroluminescent display device according to a comparative example. According to the comparative example, the data driver 12 applies a sensing voltage (e.g., 4.5V) to a W data line DL_W, which is connected to a W sub-pixel that serves as a sensing pixel among the sub-pixels of a shared readout line SIO, and can apply a voltage (e.g., 0V) to keep the driving TFTs of non-sensing pixels in an off state to data lines DL_R, DL_G, and DL_B connected to the non-sensing pixels.

[0075] Reference Figure 4 and Figure 5 The sensing method according to the comparative example may include an initialization period ①, a sensing period ②, and a sampling period ③.

[0076] During the initialization period ①, when the scan control signal SCAN / SENSE, which is at the on level, is applied to the gate line GL, the first switch TFT ST1 and the second switch TFT ST2 of the four sub-pixels are both turned on.

[0077] During initialization period ①, when an on-level signal is applied to the initialization switch SPRE, the initialization switch SPRE is turned on and an initialization voltage Vpre is provided to the readout line SIO. The sampling switch SAM is turned off by an off-level signal, thus canceling the connection between the readout line SIO and the ADC of the sensing circuit 14. The initialization voltage Vpre provided to the readout line SIO is applied to the source electrode of the driving TFT DT included in the sub-pixel. Unlike the sensing pixel, the driving TFT DT must not be turned on in the non-sensing pixel. For this reason, it is desirable to set the difference between the voltage applied to the non-sensing pixel and the initialization voltage Vpre to a value lower than the threshold voltage of the driving TFT DT. Furthermore, since the initialization voltage Vpre is applied to the sub-pixels within the unit pixel, it is desirable to set the initialization voltage Vpre to a value lower than the threshold voltage (operating point voltage) of the light-emitting element OLED to prevent the non-sensing pixels from being unnecessarily turned on.

[0078] During initialization period ①, a voltage of 4.5V is applied to the data line DL_W of the sensing pixel, and a voltage of 0V is applied to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels. Therefore, during initialization period ①, the driving TFT DT included in the sensing pixel W is programmed to allow pixel current to flow, and the driving TFT DT included in the non-sensing pixels R, G, and B is programmed to prevent pixel current from flowing.

[0079] During the sensing period ②, the initialization switch SPRE is turned off, so the voltage of the read line SIO can be increased.

[0080] During sensing period ②, current Ids flows through the driving TFT DT of the sensing pixel W, thus gradually increasing the voltage of the source node. The voltage of the source node is boosted to the voltage of the gate electrode of the driving TFT DT until the difference between the voltage of the gate node and the voltage of the source node corresponds to the threshold voltage Vth of the driving TFT DT. As described above, boosting the voltage of the source node of the driving TFT DT to the voltage of the gate electrode of the driving TFT DT is called "source following". When the voltage difference between the gate node and the source node reaches the threshold voltage Vth, the current Ids flowing through the driving TFT DT becomes zero, and the potential of the source node saturates. In this way, when the driving TFT DT of the sensing pixel W operates in source following mode during sensing period ②, the source voltage of the driving TFT DT is stored in the line capacitor C of the readout line SIO. para middle.

[0081] During sampling period ③, the sampling switch SAM is turned on by an on-level signal to connect the readout line (SIO) and the ADC. Therefore, the source voltage value of the driving TFT DT stored in the readout line SIO can be sampled. Then, the difference (4.5V - Sen = Φ) between the voltage value applied to the sensing pixel (4.5V) and the voltage sensed from the readout line SIO can be calculated to obtain the threshold voltage Vth of the driving TFT DT of the sensing pixel.

[0082] As described above, in the sensing method according to the comparative example, 0V is applied to the non-sensing pixel and the data voltage (4.5V) used for sensing is applied to the sensing pixel, and the line capacitor C stored in the readout line SIO is activated by a source follower operation. para The source voltage of the driving TFT DT is sampled.

[0083] However, since in the sensing method according to the comparative example, a data voltage is applied to the data line DL_W of the sensing pixel and 0V is applied to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels, the line capacitance C of the readout line SIO arranged together with the data line DL is... para Increase. In other words, due to the potential difference between the data lines DL_R, DL_G, and DL_B of the non-sensing pixels, which have a potential of 0V, and the readout line SIO, which stores the sensing voltage, the line capacitance of the readout line SIO increases, resulting in an increase in sensing time.

[0084] To mitigate this issue, in embodiments of this disclosure, the potential difference between the data line DL and the readout line SIO of the non-sensing pixel is eliminated, thereby eliminating the capacitance generated between the data line DL and the readout line SIO. Consequently, the capacitance of the readout line SIO is reduced, thus decreasing the time the source voltage of the sensing pixel is charged in the readout line SIO, thereby reducing the sensing time.

[0085] Figure 6 and Figure 7 This is a diagram illustrating a method for sensing the electrical characteristics of an electroluminescent display device according to an embodiment. Figure 6 This is a diagram illustrating a schematic pixel structure of an electroluminescent display device according to an embodiment and the operation of sub-pixels during sensing operation, and Figure 7 It shows in Figure 6 The control signal waveform and potential change waveform for each time period during the sensing operation.

[0086] Reference Figure 6 The electroluminescent display device according to the embodiment may further include a feedback unit 70, which feeds back the voltage of the readout line SIO to the data line of the non-sensing pixel in the pixel structure in which four sub-pixels share a readout line SIO.

[0087] The four sub-pixels share a readout line SIO and a gate line GL. The four sub-pixels are connected to the R data line DL_R, which provides R (red) data, the W data line DL_W, which provides W (white) data, the G data line DL_G, which provides G (green) data, and the B data line DL_B, which provides B (blue) data.

[0088] Feedback unit 70 feeds back a voltage with the same potential as the voltage of the readout line SIO to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels, so that no potential difference is generated between the readout line SIO and the data lines DL_R, DL_G, and DL_B. Feedback unit 70 may include: an amplifier Amp, which receives the sensed voltage of the readout line SIO, applies a preset gain to it, and outputs the sensed voltage with the applied gain; and a feedback switch SW, which connects the output terminal of the amplifier to the data lines of the non-sensing pixels.

[0089] As an amplifier Amp, a non-inverting amplifier can be used in which the voltage of the readout line SIO is input to the non-inverting terminal (+) and the output voltage is fed back to the inverting terminal (-). In a non-inverting amplifier, the input and output voltages have the same polarity, and the gain can be adjusted according to the ratio of the input resistor R1 to the feedback resistor R2 inserted in the output voltage feedback line. The output voltage Vout of such an amplifier can be expressed as follows.

[0090] <Amplifier output voltage>

[0091]

[0092] As mentioned above, the gain value (1+R2 / R1) is determined by the ratio of the sizes of resistors R1 and R2. The desired correct gain value can be obtained if the resistors R1 and R2, which determine the gain, are designed as variable resistors that can be adjusted digitally. The amplifier gain can be set such that the voltage on the readout line SIO and the voltage on the data line DL fed back to the non-sensing pixel have the same potential for as long as possible, and the gain can be set such that it is output within a range where the non-sensing pixel will not be turned on by the voltage fed back to the data line.

[0093] A feedback switch SW is inserted into the connection line between the data line DL of each sub-pixel and the output terminal of the amplifier. The feedback switch SW can be connected to each of the four data lines DL_R, DL_W, DL_G, and DL_B. When the switch SW is on, the corresponding data line DL is connected to the output terminal of the amplifier, and when the switch SW is off, the connection between the corresponding data line DL and the output terminal of the amplifier is canceled. The feedback switch SW operates such that the output terminal of the amplifier is connected to the data line of the non-sensing pixel. The on / off operation of the feedback switch SW can be controlled by, but is not limited to, the timing controller 11 that controls the sensing operation.

[0094] The above configuration of the feedback unit 70 is only one implementation method, and various circuit configurations that can feed back a voltage with the same potential as the voltage of the readout line SIO to the data line DL of the non-sensing pixel can be applied.

[0095] When sensing the electrical characteristics of a W sub-pixel in an electroluminescent display device according to an embodiment having the above configuration, a sensing voltage (e.g., 4.5V) is applied to the W data line DL_W, and a voltage having the same potential as the readout line SIO is applied to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels.

[0096] Reference Figure 7 The sensing method according to the implementation method may include an initialization period ①, a sensing period ②, and a sampling period ③.

[0097] During the initialization period ①, when the on-level scan control signal SCAN / SENSE is applied to the gate line GL, the first switch TFT ST1 and the second switch TFT ST2 of the four sub-pixels are both turned on.

[0098] During initialization period ①, when an on-level signal is applied to the initialization switch SPRE, the initialization switch SPRE is turned on and an initialization voltage Vpre is provided to the readout line SIO. The sampling switch SAM is turned off by an off-level signal, thus disconnecting the connection between the readout line SIO and the ADC of the sensing circuit 14. The initialization voltage Vpre provided to the readout line SIO is applied to the source electrode of the driving TFT DT included in the sub-pixel.

[0099] During initialization period ①, a sensing voltage (e.g., 4.5V) is applied to the W data line DL_W, which is connected to the W sub-pixel that serves as the sensing pixel. Therefore, during initialization period ①, the driving TFT DT included in the sensing pixel W is programmed to allow pixel current to flow.

[0100] During sensing period ②, the initialization switch SPRE is turned off, allowing the voltage of the readout line SIO to increase. Therefore, the voltage of the readout line SIO can be input to the non-inverting terminal (+) of the amplifier included in the feedback unit 70. The feedback switches SW connected to the data lines DL_R, DL_W, DL_G, and DL_B of the non-sensing pixel are turned on, connecting the data lines DL_R, DL_W, DL_G, and DL_B to the readout line SIO. The switch connected to the W data line DL_W, which is connected to the W sub-pixel that is the sensing pixel, remains off.

[0101] During the sensing period ②, the driving TFT DT of the sensing pixel W performs a source follower operation to increase the voltage between the source node and the readout line SIO connected to the source node.

[0102] The voltage of the readout line SIO is input to the non-inverting terminal (+) of the amplifier in the feedback unit 70. The amplifier receives the voltage of the readout line SIO and outputs a voltage having the same potential as the voltage of the readout line SIO to the data lines DL_R, DL_G, and DL_B of the non-sensing pixel. Therefore, the readout line SIO has the same potential as the data lines DL_R, DL_G, and DL_B of the non-sensing pixel, and thus the line capacitance of the readout line SIO is reduced compared to the comparative example. Therefore, compared to the comparative example (before), the time for charging the saturation voltage of the source node in the readout line SIO can be reduced, and therefore, the sensing period ② can be reduced in the embodiment (described later).

[0103] During sampling period ③, the sampling switch SAM is turned on by an on-level signal to connect the readout line (SIO) and the ADC. Therefore, the source voltage value of the driving TFT DT stored in the readout line SIO can be sampled. Subsequently, the threshold voltage Vth of the driving TFT DT can be obtained by calculating the difference (4.5V - Sen = Φ) between the W data value Vdata_W applied to the sensing pixel and the sensing voltage Sen. In the embodiment described below, the sensing period ② can be reduced compared to the comparative example described above, and therefore sampling can be performed faster in the embodiment described below compared to the comparative example described above. Therefore, the overall sensing time can be reduced.

[0104] As described above, in the sensing method according to the embodiment, a data voltage for sensing is applied to the data line DL of the sensing pixel, and a voltage having the same potential as the voltage of the readout line SIO is fed back to the data line DL of the non-sensing pixel. Therefore, the capacitance generated due to the potential difference between the readout line SIO and the data line DL of the non-sensing pixel can be removed, thereby reducing the capacitance of the readout line SIO to shorten the sensing time.

[0105] Figure 8 It shows the basis Figure 6 The diagram shows the equivalent circuit during sensing operation of the electroluminescent display device of the first embodiment, and illustrates the case where the W sub-pixel of the R, W, G, and B sub-pixels sharing the readout line SIO is sensed. (Refer to...) Figure 8 The sensing voltage provided by the DAC of the data driver 12 is applied to the W data line DL_W, which is connected to the W sub-pixel, which is the sensing pixel. The driving TFT DT of the sensing pixel W, which has been provided with the sensing voltage, performs a source follower operation, thus increasing the voltage at the source node. Therefore, the voltage at the source node of the sensing pixel W is charged in the line capacitor Cpara of the readout line SIO connected to the source node. Subsequently, when the sampling switch SAM is turned on, the readout line SIO and the ADC can be connected to sample the source voltage value of the driving TFT DT stored in the readout line SIO.

[0106] Data lines DL_R, DL_W, DL_G, and DL_B, which connect to the non-sensing pixels R, G, and B, are connected to the readout line SIO via feedback unit 80. A voltage provided by feedback unit 80 is applied to the data lines DL_R, DL_G, and DL_B connected to the non-sensing pixels R, G, and B. The voltage provided by feedback unit 80 has the same value as the voltage of the readout line SIO. Therefore, the capacitance C between the data lines DL_R, DL_W, DL_G, and DL_B of the non-sensing pixels R, G, and B and the readout line SIO can be removed. DtoSIO .

[0107] Here, the feedback unit 80 includes: an amplifier Amp that receives and outputs the sensed voltage of the readout line SIO; and feedback switches SW1 and SW2 that connect the output terminals of the amplifier to the data lines of the non-sensing pixels.

[0108] As an amplifier (Amp), a non-inverting amplifier can be used where the voltage of the readout line SIO is input to the non-inverting terminal (+) and the output voltage is fed back to the inverting terminal (-). In a non-inverting amplifier, the input and output voltages have the same polarity, and the gain can be adjusted according to the ratio of the input resistor R1 and the feedback resistor R2 inserted in the output voltage feedback line. The resistors R1 and R2, which determine the gain, can be designed as follows: Figure 8 The variable resistor shown can also be implemented as a fixed resistor.

[0109] The first feedback switch SW1 controls the connection between the data line DL and the DAC of the data driver 12, and the second feedback switch SW2 controls the connection between the data line DL and the feedback unit 80.

[0110] When a sensing voltage is applied during sensing operation or an image data voltage is applied during display operation, the first feedback switch SW1 is turned on, causing the data line DL to be connected to the data driver 12.

[0111] When a non-sensing pixel is selected during sensing operation, the second feedback switch SW2 is turned on, connecting the data line DL to the output line of the amplifier in the feedback unit 80. The feedback unit 80 applies the same voltage as the readout line SIO to the data line DL. Therefore, the capacitance C between the data lines DL_R, DL_G, and DL_B of the non-sensing pixels R, G, and B and the readout line SIO is... DtoSIO The removal of the source voltage of the sensing pixel reduces the time required for the source voltage of the sensing pixel to be charged in the readout line SIO, thereby shortening the sensing time.

[0112] Figure 9 This is a diagram showing the circuit of an electroluminescent display device according to a second embodiment of the present disclosure.

[0113] When a fault such as an OLED short circuit occurs, an overflow voltage exceeding the ADC output range due to pixel current leakage may be applied to the readout line SIO. If the fault causes an overflow, a very high voltage V_Overflow is applied to the readout line SIO. Therefore, when the feedback unit 90 applies the same voltage as the readout line SIO to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels, a fault of non-sensing pixel turn-on may occur. A second embodiment of this disclosure may also include a configuration for preventing such faults.

[0114] An electroluminescent display device according to a second embodiment of the present disclosure includes: a feedback unit 90 that outputs a feedback voltage corresponding to the voltage of a readout line SIO; a defective pixel determination unit 100 that determines whether a sense pixel is defective; and a selector 110 that selects a voltage input to each of data lines DL_R, DL_W, DL_G, and DL_B in a pixel structure in which four sub-pixels share a readout line SIO based on the determination result of the defective pixel determination unit 100.

[0115] Figure 9 The circuit connections between the data lines DL_W of the sensing pixels, DL_R, DL_G and DL_B of the non-sensing pixels, the readout line SIO, the feedback unit 90, the defective pixel determination unit 100, and the selector 110 are shown.

[0116] Feedback unit 90 receives the sensed voltage of the read line SIO and outputs a voltage with the same potential as the voltage of the read line SIO. Feedback unit 90 may include an amplifier Amp, which receives the sensed voltage of the read line SIO, applies a preset gain to it, and outputs the sensed voltage with the applied gain. As amplifier Amp, a non-inverting amplifier can be used, in which the voltage of the read line SIO is input to the non-inverting terminal (+) and the output voltage is fed back to the inverting terminal (-). In the non-inverting amplifier, the input voltage and output voltage have the same polarity, and the gain can be adjusted according to the ratio of the input resistor R1 and the feedback resistor R2 inserted into the output voltage feedback line.

[0117] The defective pixel determination unit 100 compares the voltage of the readout line SIO with a preset overflow voltage and outputs the comparison result to the selector 110. The defective pixel determination unit 100 may include a comparator and a setting circuit 105 for setting a reference voltage at the non-inverting terminal (-) of the comparator.

[0118] The comparator compares the voltage input to its inverting terminal (-) with the voltage input to its non-inverting terminal (+). If the voltage input to the non-inverting terminal (+) is lower, it outputs a logic value "0"; if the voltage input to the non-inverting terminal (+) is higher, it outputs a logic value "1". The readout line SIO is connected to the non-inverting terminal (+) of the comparator. A setting circuit 105, used to set the reference voltage for determining defective pixels, is connected to the inverting terminal (-). If the voltage input to the readout line SIO at the non-inverting terminal (+) is lower, the comparator outputs a logic value "0"; if the voltage is higher, the comparator outputs a logic value "1". When the voltage on the readout line SIO is higher, the corresponding pixel can be identified as a defective pixel. Therefore, the comparator output can be logic "1" in the case of a defective pixel and logic "0" in the case of a normal pixel.

[0119] The setting circuit 105 applies a reference voltage used to determine the defective pixel to the inverting terminal (-) of the comparator. The setting circuit 105 may include first to fourth switches SW01, SW02, SW03, and SW04, and a reference voltage capacitor C storing the comparator's reference voltage. REF The setting circuit 105 can use the sub-pixel voltage EVSS and the preset programming voltage V. program The reference voltage input to the inverting terminal (-) of the comparator is stored in the reference voltage capacitor C. REF The specific method for storing the reference voltage in the setting circuit 105 will be described in detail later.

[0120] The defective pixel determination unit 100, which includes the aforementioned components, compares the voltage of the readout line SIO with a preset overflow voltage and outputs the comparison result to the selector 110. Through the comparator, the defective pixel determination unit 100 can output a logic value "1" when there is a defective pixel and output a logic value "0" when there is a normal pixel.

[0121] Selector 110 selects the voltage to be applied to each of the data lines DL_R, DL_W, DL_G, and DL_B based on the determination result of defect pixel determination unit 100. Selector 110 may include: a multiplexer MUX disposed on each data line DL and selectively applying the output of DAC or the output of feedback unit 90 based on the determination result of defect pixel determination unit 100; a switch selectively connecting the output line of MUX and the data line DL; and a switch selectively connecting DAC and the data line DL.

[0122] Reference Figure 9 The selector 110 includes a first multiplexer MUX1 inserted between the data lines DL_W and DAC of the sensing pixels, a second multiplexer MUX2 inserted between the data lines DL_R, DL_G and DL_B of the non-sensing pixels and DAC, and fifth to eighth switches SW05, SW06, SW07 and SW08 for controlling the connection of each data line.

[0123] In selector 110, the data line DL_W of the sensing pixel is branched into two lines, one of which is connected to the DAC of data driver 12 via the fifth switch SW05, and the other line is connected to the first multiplexer MUX1 via the sixth switch SW06.

[0124] The fifth switch SW05 is selected by the W signal SW. SEL_W Turn on to connect the data line DL_W of the sensing pixel to the DAC.

[0125] The sixth switch SW06 is selected by the readout line selection signal SW SIO_W Turn on to connect the first multiplexer MUX1 to the data line DL_W.

[0126] The first multiplexer MUX1 outputs the voltage of the output line of the DAC of the data driver 12 or the voltage of the read line SIO. When a logic value "1" indicating a defective pixel is input from the defective pixel determination unit 100, the first multiplexer MUX1 outputs the output voltage of the DAC, and when a logic value "0" indicating a normal pixel is input, the first multiplexer MUX1 outputs the voltage of the feedback unit 90.

[0127] In selector 110, each of the data lines DL_R, DL_G and DL_B of the non-sensing pixels is branched into two lines, one of which is connected to the DAC of data driver 12 via the eighth switch SW08, and the other line is connected to the second multiplexer MUX2 via the seventh switch SW07.

[0128] The eighth switch SW08 is selected by the R, G, and B signals SW. SEL_R / G / B Turn on to connect the data lines DL_R, DL_G, and DL_B of the non-sensing pixels to the DAC.

[0129] The seventh switch SW07 is selected by the readout line signal SW SIO_R / G / B Turn on to connect the second multiplexer MUX2 to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels.

[0130] The second multiplexer MUX2 outputs the voltage of the output line of the DAC of the data driver 12 or the voltage of the read line SIO. When a logic value "1" indicating a defective pixel is input from the defective pixel determination unit 100, the second multiplexer MUX2 outputs the output voltage of the DAC, and when a logic value "0" indicating a normal pixel is input, the second multiplexer MUX2 outputs the voltage of the feedback unit 90.

[0131] Using this configuration, the defective pixel determination unit 100 determines whether the voltage of the readout line SIO is equal to or greater than a reference voltage, and outputs the determination result in the electroluminescent display device according to the second embodiment of the present disclosure. The determination result output from the defective pixel determination unit 100 is input to the selector 110. If the voltage of the readout line SIO is lower than the reference voltage, the selector 110 applies the output voltage of the feedback unit 90 to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels. If the voltage of the readout line SIO is higher than the reference voltage, the selector 110 connects the output line of the DAC to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels. Therefore, when an overflow voltage is applied to the readout line SIO due to a defective sub-pixel, the voltage of the readout line SIO can be prevented from being applied to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels.

[0132] Figures 10 to 12 It is used to describe Figure 9 The diagram shows the operation of the setting circuit 105.

[0133] The setting circuit 105 includes first to fourth switches SW01, SW02, SW03, and SW04, and a reference voltage capacitor C storing the reference voltage of the comparator. REF .

[0134] The first switch SW01 is selected by the EVSS selection signal SW.EVSS When switched on, the reference voltage capacitor C... REF The second electrode is connected to the voltage EVSS of the sub-pixel.

[0135] The second switch SW02 is selected by the reference voltage signal SW. REF When switched on, the reference voltage capacitor C... REF The second electrode is connected to the inverting terminal (-) of the comparator.

[0136] The third switch SW03 is selected by the programmable selection signal SW. pro When switched on, the reference voltage capacitor C... REF The first electrode is connected to a preset programming voltage V. program .

[0137] The fourth switch SW04 is controlled by the flow selection signal SW. flow When switched on, the capacitor C stored at the reference voltage is switched on. REF Charge flow in the first electrode.

[0138] The operation of storing the comparator's reference voltage in the setting circuit 105 with the above configuration may include the first to third time periods T1 to T3.

[0139] Reference Figure 10 During the first time period T1, the third switch SW03 is selected by the programmed selection signal SW. pro Connected. Therefore, the programming voltage V... program The reference voltage capacitor C is applied via the third switch SW03. REF The first electrode.

[0140] Reference Figure 11 With the third switch SW03 on, the first switch SW01 is selected by the EVSS signal SW. EVSS When switched on, voltage EVSS is applied to the reference voltage capacitor C during the second time period T2. REF The second electrode. Therefore, voltage EVSS is applied to the reference voltage capacitor C. REF The first electrode, and the programming voltage V program The capacitor C is applied to the reference voltage. REF The second electrode.

[0141] Reference Figure 12 In the third time period T3, the fourth switch SW04 is first activated by the flow selection signal SW. flow When switched on, the reference voltage capacitor C... REF The voltage drop of the first electrode is the programming voltage V. program (①). Therefore, the voltage "EVSS-V" program "The capacitor C charged to the reference voltage"REF In the middle. Afterwards, the second switch SW02 is selected by the reference voltage signal SW. REF When switched on, the reference voltage capacitor C... REF The second electrode is connected to the inverting terminal (-) of the comparator. Therefore, the reference voltage of the comparator is set to voltage "EVSS-V". program Afterwards, the comparator can convert the voltage "EVSS-V" to "EVSS-V". program "Compare the voltage with the readout line SIO and output the comparison result."

[0142] Figure 13 This is a diagram illustrating the circuitry of an electroluminescent display device according to a third embodiment of the present disclosure. (Simplified) Figure 9 The configuration of the defect pixel determination unit 100 in the second embodiment is used to configure the third embodiment. Therefore, with Figure 9 Identical parts are indicated by the same reference numerals, and repeated descriptions of identical parts will be omitted.

[0143] Reference Figure 13 The electroluminescent display device according to the third embodiment of the present disclosure includes: a feedback unit 90 that outputs a feedback voltage corresponding to the voltage of the readout line SIO; a defective pixel determination unit 95 that determines whether a sense pixel is defective; and a selector 110 that selects a voltage input to each of the data lines DL_R, DL_W, DL_G and DL_B based on the defective pixel determination result.

[0144] The defective pixel determination unit 95 compares the voltage of the readout line SIO with a preset overflow voltage and outputs the comparison result to the selector 110. The defective pixel determination unit 95 may include a comparator.

[0145] The readout line SIO is connected to the non-inverting terminal (+) of the comparator. Preset programming voltage V. program The reference voltage is input to the inverting terminal (-). Programming voltage V program It can be set as a standard voltage for determining defective pixels, such as a voltage close to the overflow voltage.

[0146] If the voltage input to the read line SIO at the non-inverting terminal (+) is higher than the programming voltage V input to the inverting terminal (-), program The comparator outputs a logic value of "1", and if the voltage on the read line SIO input to the non-inverting terminal (+) is lower than the programming voltage V, the comparator will output a logic value of "1". program If the comparator outputs a logic value of "0", then the comparator will output a logic value of "0".

[0147] Therefore, when an overflow occurs due to a fault such as an OLED short circuit, the defective pixel determination unit 95 can output a logic value "1".

[0148] Using this configuration, the defective pixel determination unit 95 determines whether the voltage of the readout line SIO is equal to or greater than the preset programming voltage V. program The determination result is output in the electroluminescent display device according to the third embodiment of this disclosure. The determination result output from the defective pixel determination unit 95 is input to the selector 110. When the voltage of the readout line SIO is lower than the reference voltage, the selector 110 applies the output voltage of the feedback unit 90 to the DL_R, DL_G, and DL_B rows of the non-sensing pixels. When the voltage of the readout line SIO is higher than the reference voltage, the selector 110 connects the output line of the DAC to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels. Therefore, when an overflow voltage is applied to the readout line SIO due to a defective sub-pixel, the voltage of the readout line SIO can be prevented from being applied to the data lines DL_R, DL_G, and DL_B of the non-sensing pixels.

[0149] Figure 14 This is a graph showing the simulation results of an electroluminescent display device according to an embodiment of the present disclosure.

[0150] Figure 14 This is a graph showing the potential change in the simulated readout line SIO based on the gain of the feedback unit 90. In the graph, the horizontal axis represents time, and the vertical axis represents the voltage of the readout line SIO.

[0151] During sensing operation, the driving TFT is driven in a source-follower manner, so the potential of the source node gradually increases and then enters a saturation state. This potential change in the source node is sensed by the readout line SIO.

[0152] Figure 14 The graph shows the results of simulating the voltage change (SIOLine V) in the readout line SIO over time as follows: when using a conventional readout line sensing method (conventional), when the voltage obtained by applying Gain=1 to the sensing voltage of the readout line SIO is applied to the data line of the non-sensing pixel, when the voltage obtained by applying Gain=1.5 to the sensing voltage is applied to the data line of the non-sensing pixel, when the voltage obtained by applying Gain=3 to the sensing voltage is applied to the data line of the non-sensing pixel, and when the voltage obtained by applying Gain=5 to the sensing voltage is applied to the data line of the non-sensing pixel.

[0153] Comparing the voltage (SIO Line V) of the readout line at the same time point of 24ms, it can be determined that the highest voltage is measured when a gain of 5 is applied, and the voltage (SIO Line V) of the readout line gradually decreases as the gain decreases. The voltage (SIO Line V) of the readout line is lowest when using the conventional readout line sensing method (conventional). Therefore, it can be determined that the charging time of the readout line SIO decreases as the voltage of the readout line SIO is fed back to the data line of the non-sensing pixel by applying a high gain.

[0154] By comparing the time taken to measure the same voltage, it can be determined that when the applied gain is 5, the corresponding voltage is reached in the shortest time (24ms), and the time required to reach the same voltage gradually increases as the gain decreases.

[0155] Based on the simulation results above, when a predetermined gain is applied to the voltage of the readout line (SIO Line V) and the voltage is applied to the data line of the non-sensing pixel, the sensing time can be reduced, and the sensing time can be reduced as the gain value increases.

[0156] Those skilled in the art will understand that various modifications and changes can be made to this disclosure without departing from the spirit or scope thereof. Therefore, this disclosure should not be limited to the specific embodiments described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electroluminescent display device, comprising: The display panel includes a plurality of pixels, the plurality of pixels including sensing pixels and non-sensing pixels connected to corresponding data lines in a plurality of data lines, the plurality of pixels sharing a sensing line; A sensing circuit configured to sense the electrical characteristic value of the sensing pixel based on a sensing voltage on a shared sensing line; as well as A feedback unit is configured to apply a feedback voltage, determined based on the sensing voltage on the shared sensing line, to the data line of the non-sensing pixel. The feedback unit includes: An amplifier configured to receive the sensed voltage, apply a preset gain to the sensed voltage, and output the sensed voltage with the applied preset gain as the feedback voltage; and A feedback switch is configured to connect the output line of the amplifier to the data line of the non-sensing pixel.

2. The electroluminescent display device according to claim 1, wherein, The feedback voltage has a voltage value that minimizes the potential difference between the shared sensing line and the data line of the non-sensing pixel.

3. The electroluminescent display device according to claim 1, further comprising a data driver configured to provide a data voltage for sensing to a data line of the sensing pixel.

4. The electroluminescent display device according to claim 1, wherein, The preset gain is set such that applying the feedback voltage does not cause the non-sensing pixel to be turned on.

5. The electroluminescent display device according to claim 1, wherein, The amplifier includes: A non-inverting amplifier includes a non-inverting input terminal connected to the shared sensing line and an inverting input terminal connected to a feedback line of the output terminal of the non-inverting amplifier, the output terminal being connected to the data line of the non-sensing pixel; A first resistor is connected to the inverting input terminal; and A second resistor is connected to the feedback line.

6. The electroluminescent display device according to claim 5, wherein, The first resistor and the second resistor include variable resistors.

7. An electroluminescent display device, comprising: The display panel includes a plurality of pixels, the plurality of pixels including sensing pixels and non-sensing pixels connected to corresponding data lines in a plurality of data lines, the plurality of pixels sharing a sensing line; A sensing circuit configured to sense the electrical characteristic value of the sensing pixel based on a sensing voltage on a shared sensing line; A feedback unit is configured to determine a feedback voltage to be applied to the data line of the non-sensing pixel based on the sensing voltage on the shared sensing line; as well as A defective pixel determination unit is configured to compare the sensed voltage with a preset reference voltage, and if the sensed voltage is equal to or greater than the reference voltage, control the feedback voltage not to be applied to the data line of the non-sensing pixel.

8. The electroluminescent display device according to claim 7, wherein, The defect pixel determination unit includes a non-inverting input terminal connected to the shared sensing line, an inverting input terminal to which the reference voltage is input, and a comparator configured to output a comparison result between the sensing voltage and the reference voltage.

9. The electroluminescent display device according to claim 7, further comprising: A data driver configured to provide a data voltage for sensing to the data line of the sensing pixel; and A selector configured to apply the feedback voltage or the data voltage output from the data driver to the corresponding data line based on the determination result of the defective pixel determination unit.

10. The electroluminescent display device according to claim 9, wherein, The selector includes a multiplexer configured to output the feedback voltage to the data line of the non-sensing pixel when the sensing voltage is less than the reference voltage, and to apply the data voltage output from the data driver to the data line of the sensing pixel when the sensing voltage is equal to or greater than the reference voltage.

11. The electroluminescent display device according to claim 7, wherein, The electrical characteristic values ​​of the sensing pixel include the threshold voltage value of the driving thin-film transistor of the sensing pixel.

12. The electroluminescent display device of claim 7, further comprising a compensator configured to determine a data compensation amount for each of the plurality of pixels based on sensing data received from the sensing circuit, wherein the sensing data is obtained by converting the sensing voltage.

13. A method for sensing electrical characteristics of an electroluminescent display device, the electroluminescent display device comprising a display panel having a plurality of pixels, the plurality of pixels including sensing pixels and non-sensing pixels connected to corresponding data lines of a plurality of data lines, the plurality of pixels sharing a sensing line, the method comprising: Provide a data voltage for sensing to the data line of the sensing pixel; The sense voltage applied to the shared sense line is compared with a preset reference voltage; When the sensing voltage is less than the reference voltage, a feedback voltage based on the sensing voltage is applied to the data line of the non-sensing pixel; as well as The electrical characteristic value of the sensing pixel is sensed based on the sensing voltage on the shared sensing line.

14. The method according to claim 13, wherein, The feedback voltage has a voltage value that minimizes the potential difference between the shared sensing line and the data line of the non-sensing pixel.

15. The method of claim 13, further comprising, when the sensing voltage is higher than the reference voltage, applying a data voltage output from the data driver to the data line of the non-sensing pixel.

16. The method of claim 13, further comprising applying a data voltage output from the data driver to the data line of the sensing pixel when the sensing voltage is equal to or greater than the reference voltage.

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