Pixel circuit and display device including the same

Abstract

The present invention relates to a pixel circuit and a display device including the pixel circuit. The pixel circuit includes a first pixel. The first pixel includes first and second switching elements, a first light-emitting element, and third and fourth switching elements. The first switching element includes a control electrode connected to a first node, an input electrode to which a first power supply voltage is applied, and an output electrode connected to a second node. The second switching element includes a control electrode to which a first signal is applied, an input electrode to which a first data voltage is applied, and an output electrode connected to the first node. The first light-emitting element includes a first electrode connected to a second node and a second electrode to which a second power supply voltage is applied. The third switching element includes a control electrode to which a second signal is applied, an input electrode connected to the second node, and an output electrode connected to a third node. The fourth switching element includes a control electrode to which a third signal is applied, an input electrode connected to the third node, and an output electrode connected to a sensing line.

Description

Technical Field

[0001] The present invention relates to a pixel circuit and a display device including the pixel circuit, and in particular to a pixel circuit capable of improving the compensation accuracy of the threshold voltage of a switching element of the pixel circuit and thereby improving the display quality of a display panel, and a display device including the pixel circuit. Background Art

[0002] Typically, a display device includes a display panel and a display panel driver. The display panel includes multiple gate lines, multiple data lines, and multiple pixels. The display panel driver includes a gate driver that provides gate signals to the multiple gate lines; a data driver that provides data voltages to the data lines; a drive control unit that controls the gate and data drivers; and a power supply voltage generator that provides power supply voltage to the display panel.

[0003] A problem exists: variations in the threshold voltages of switching elements arranged within the pixels of the display panel prevent the uniformity of the displayed image from being ensured. To compensate for these variations in the threshold voltages of the switching elements, sensing switching elements may be arranged within the pixels of the display panel. However, when the sensing switching elements are used to sense the voltage of the pixels to compensate for these variations in threshold voltages, damage to adjacent pixels can reduce the accuracy of the sensing. Summary of the Invention

[0004] Therefore, the technical problem of the present invention is proposed based on these problems, and an object of the present invention is to provide a pixel circuit capable of improving the compensation accuracy of the threshold voltage of the switching element of the pixel circuit.

[0005] Another object of the present invention is to provide a display device including the pixel circuit.

[0006] A pixel circuit according to one embodiment for achieving the above-mentioned purpose of the present invention includes a first pixel. The first pixel includes a first switching element, a second switching element, a first light-emitting element, a third switching element, and a fourth switching element. The first switching element includes a control electrode connected to a first node, an input electrode to which a first power supply voltage is applied, and an output electrode connected to a second node. The second switching element includes a control electrode to which a first signal is applied, an input electrode to which a first data voltage is applied, and an output electrode connected to the first node. The first light-emitting element includes a first electrode connected to the second node and a second electrode to which a second power supply voltage is applied. The third switching element includes a control electrode to which a second signal is applied, an input electrode connected to the second node, and an output electrode connected to a third node. The fourth switching element includes a control electrode to which a third signal is applied, an input electrode connected to the third node, and an output electrode connected to a sensing line.

[0007] According to an embodiment of the present invention, an activation period of the third signal may at least partially overlap with an activation period of the first data voltage.

[0008] According to an embodiment of the present invention, the control electrode of the fourth switching element may be connected to the input electrode of the second switching element.

[0009] According to an embodiment of the present invention, the pixel circuit may further include a second pixel and a third pixel. The second pixel may include: a fifth switching element including a control electrode connected to a fourth node, an input electrode to which the first power supply voltage is applied, and an output electrode connected to a fifth node; a sixth switching element including a control electrode to which the first signal is applied, an input electrode to which a second data voltage having a phase different from that of the first data voltage is applied, and an output electrode connected to the fourth node; a second light-emitting element including a first electrode connected to the fifth node and a second electrode to which the second power supply voltage is applied; a seventh switching element including a control electrode to which the second signal is applied, an input electrode connected to the fifth node, and an output electrode connected to a sixth node; and an eighth switching element including a control electrode to which a fourth signal is applied, an input electrode connected to the sixth node, and an output electrode connected to the sensing line. The third pixel may include: a ninth switching element, including a control electrode connected to the seventh node, an input electrode to which the first power supply voltage is applied, and an output electrode connected to the eighth node; a tenth switching element, including a control electrode to which the first signal is applied, an input electrode to which a third data voltage having a phase different from that of the first data voltage and the second data voltage is applied, and an output electrode connected to the seventh node; a third light-emitting element, including a first electrode connected to the eighth node and a second electrode to which the second power supply voltage is applied; an eleventh switching element, including a control electrode to which the second signal is applied, an input electrode connected to the eighth node, and an output electrode connected to the ninth node; and a twelfth switching element, including a control electrode to which the fifth signal is applied, an input electrode connected to the ninth node, and an output electrode connected to the sensing line.

[0010] According to an embodiment of the present invention, the activation period of the third signal may at least partially overlap with the activation period of the first data voltage. The activation period of the fourth signal may at least partially overlap with the activation period of the second data voltage. The activation period of the fifth signal may at least partially overlap with the activation period of the third data voltage.

[0011] According to an embodiment of the present invention, the activation period of the third signal, the activation period of the fourth signal, and the activation period of the fifth signal may not overlap with each other.

[0012] According to one embodiment of the present invention, the control electrode of the fourth switching element may be connected to the input electrode of the second switching element. The control electrode of the eighth switching element may be connected to the input electrode of the sixth switching element. The control electrode of the twelfth switching element may be connected to the input electrode of the tenth switching element.

[0013] According to one embodiment of the present invention, the first light-emitting element may present a first color, the second light-emitting element may present a second color different from the first color, and the third light-emitting element may present a third color different from the first color and the second color.

[0014] According to an embodiment of the present invention, the activation periods of the second signal and the third signal may at least partially overlap with the activation period of the first data voltage.

[0015] A display device according to one embodiment, for achieving the aforementioned objectives of the present invention, includes a display panel and a data driver. The display panel includes a pixel circuit including a first pixel. The display panel displays an image. The data driver outputs a data voltage to the display panel. The data driver receives a sensing voltage from the display panel. The first pixel includes a first switching element, a second switching element, a first light-emitting element, a third switching element, and a fourth switching element. The first switching element includes a control electrode connected to a first node, an input electrode to which a first power supply voltage is applied, and an output electrode connected to a second node. The second switching element includes a control electrode to which a first signal is applied, an input electrode to which a first data voltage is applied, and an output electrode connected to the first node. The first light-emitting element includes a first electrode connected to the second node and a second electrode to which a second power supply voltage is applied. The third switching element includes a control electrode to which a second signal is applied, an input electrode connected to the second node, and an output electrode connected to a third node. The fourth switching element includes a control electrode to which a third signal is applied, an input electrode connected to the third node, and an output electrode connected to a sensing line.

[0016] According to an embodiment of the present invention, an activation period of the third signal may at least partially overlap with an activation period of the first data voltage.

[0017] According to an embodiment of the present invention, the control electrode of the fourth switching element may be connected to the input electrode of the second switching element.

[0018] According to an embodiment of the present invention, in a first period of a sensing period, the first signal, the second signal, the first data voltage, the third signal, and the first sensing signal may have an active state, and the second sensing signal may have an inactive state.

[0019] According to an embodiment of the present invention, in a second period after the first period, the first signal, the second signal, the first data voltage, the third signal, the first sensing signal, and the second sensing signal may have an active state.

[0020] According to an embodiment of the present invention, in a third period after the second period, the first signal, the second signal, the first data voltage, the third signal, and the second sensing signal may be in an activated state, and the first sensing signal may be in an inactivated state.

[0021] According to an embodiment of the present invention, in a fourth period after the third period, the first signal, the second signal, the first data voltage, and the third signal may be in an activated state, and the first sensing signal and the second sensing signal may be in an inactivated state.

[0022] According to an embodiment of the present invention, during a driving period, the first signal may be scan-driven, the first data voltage and the third signal may have values corresponding to a color scale of the first pixel, and the second signal, the first sensing signal, and the second sensing signal may be in an inactive state.

[0023] According to an embodiment of the present invention, the display device may further include: a drive control unit that determines a threshold voltage of the first switching element of the first pixel based on the sensing voltage received from the sensing line, and compensates a data signal based on the threshold voltage.

[0024] In one embodiment of the present invention, the pixel circuit of the display panel may further include a second pixel and a third pixel. The second pixel may include: a fifth switching element including a control electrode connected to a fourth node, an input electrode to which the first power supply voltage is applied, and an output electrode connected to a fifth node; a sixth switching element including a control electrode to which the first signal is applied, an input electrode to which a second data voltage having a phase different from that of the first data voltage is applied, and an output electrode connected to the fourth node; a second light-emitting element including a first electrode connected to the fifth node and a second electrode to which the second power supply voltage is applied; a seventh switching element including a control electrode to which the second signal is applied, an input electrode connected to the fifth node, and an output electrode connected to a sixth node; and an eighth switching element including a control electrode to which a fourth signal is applied, an input electrode connected to the sixth node, and an output electrode connected to the sensing line. The third pixel may include: a ninth switching element, including a control electrode connected to the seventh node, an input electrode to which the first power supply voltage is applied, and an output electrode connected to the eighth node; a tenth switching element, including a control electrode to which the first signal is applied, an input electrode to which a third data voltage having a phase different from that of the first data voltage and the second data voltage is applied, and an output electrode connected to the seventh node; a third light-emitting element, including a first electrode connected to the eighth node and a second electrode to which the second power supply voltage is applied; an eleventh switching element, including a control electrode to which the second signal is applied, an input electrode connected to the eighth node, and an output electrode connected to the ninth node; and a twelfth switching element, including a control electrode to which the fifth signal is applied, an input electrode connected to the ninth node, and an output electrode connected to the sensing line.

[0025] According to an embodiment of the present invention, the activation period of the third signal may at least partially overlap with the activation period of the first data voltage. The activation period of the fourth signal may at least partially overlap with the activation period of the second data voltage. The activation period of the fifth signal may at least partially overlap with the activation period of the third data voltage.

[0026] According to an embodiment of the present invention, the activation period of the third signal, the activation period of the fourth signal, and the activation period of the fifth signal may not overlap with each other.

[0027] According to the pixel circuit and display device including the pixel circuit described above, the pixel circuit includes a first sensing switch element and a second sensing switch element connected in series with the first sensing switch element, and the control signal of the second sensing switch element has an activation period that overlaps with the data voltage of the pixel circuit. This improves the accuracy of voltage sensing in the pixel circuit. Consequently, the accuracy of compensation for the threshold voltage of the pixel switching element can be improved, thereby improving the display quality of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a block diagram illustrating a display device according to an embodiment of the present invention.

[0029] Figure 2 It shows Figure 1 The pixels of the display panel and Figure 1 1. Circuit diagram of the voltage sensing part of the data driving part.

[0030] Figure 3 is shown in the sensing period Figure 2 A timing diagram of input / output signals of the pixel and the voltage sensing unit.

[0031] Figure 4 is shown in the driving period Figure 2 A timing diagram of the input signals of the pixel and the voltage sensing unit.

[0032] Figure 5 FIG. 1 is a circuit diagram illustrating a pixel and a voltage sensing portion of a data driving portion of a display panel according to an embodiment of the present invention.

[0033] Figure 6 is shown in the first sensing period Figure 5 A timing diagram of input / output signals of the pixel and the voltage sensing unit.

[0034] Figure 7 is shown in the second sensing period Figure 5 A timing diagram of input / output signals of the pixel and the voltage sensing unit.

[0035] Figure 8 is shown in the third sensing period Figure 5 A timing diagram of input / output signals of the pixel and the voltage sensing unit.

[0036] Figure 9 FIG. 1 is a circuit diagram illustrating a pixel and a voltage sensing portion of a data driving portion of a display panel according to an embodiment of the present invention.

[0037] Figure 10 is shown in the sensing period Figure 9 A timing diagram of the input signal of the pixel.

[0038] Description of Reference Numerals

[0039] 100: Display panel 200: Drive control unit

[0040] 300: Gate driving unit 400: Gamma reference voltage generating unit

[0041] 500: Data driving unit 600: Power supply voltage generating unit DETAILED DESCRIPTION

[0042] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

[0043] Figure 1 is a block diagram illustrating a display device according to an embodiment of the present invention.

[0044] Reference Figure 1 The display device includes a display panel 100 and a display panel driving unit. The display panel driving unit includes a driving control unit 200, a gate driving unit 300, a gamma reference voltage generating unit 400, and a data driving unit 500. The display panel driving unit also includes a power supply voltage generating unit 600.

[0045] For example, the drive control unit 200 and the data driver unit 500 may be integrated. For example, the drive control unit 200, the gamma reference voltage generator 400, and the data driver unit 500 may be integrated. The driver module that includes at least the drive control unit 200 and the data driver unit 500 as an integrated unit may be named a timing controller embedded data driver (TED).

[0046] The display panel 100 includes a display portion that displays an image and a peripheral portion disposed adjacent to the display portion.

[0047] The display panel 100 includes a plurality of gate lines GL, a plurality of data lines DL, and a plurality of pixels P electrically connected to the gate lines GL and the data lines DL, respectively. The gate lines GL extend along a first direction D1, and the data lines DL extend along a second direction D2 intersecting the first direction D1. The display panel 100 may further include a plurality of sensing lines SL connected to the plurality of pixels P.

[0048] In one embodiment of the present invention, the display panel 100 may be an organic light emitting display panel including organic light emitting elements.

[0049] The drive control unit 200 receives input image data IMG and an input control signal CONT from an external device. For example, the input image data IMG may include red image data, green image data, and blue image data. The input image data IMG may include white image data. The input image data IMG may include magenta image data, yellow image data, and cyan image data. The input control signal CONT may include a main clock signal and a data enable signal. The input control signal CONT may also include a vertical synchronization signal and a horizontal synchronization signal.

[0050] The driving control unit 200 generates a first control signal CONT1 , a second control signal CONT2 , a third control signal CONT3 , and a data signal DATA based on the input image data IMG and the input control signal CONT.

[0051] The driving control part 200 generates the first control signal CONT1 for controlling the operation of the gate driving part 300 based on the input control signal CONT and outputs the first control signal CONT1 to the gate driving part 300. The first control signal CONT1 may include a vertical start signal and a gate clock signal.

[0052] The driving control part 200 generates a second control signal CONT2 for controlling the operation of the data driving part 500 based on the input control signal CONT, and outputs the second control signal CONT2 to the data driving part 500. The second control signal CONT2 may include a horizontal start signal and a load signal.

[0053] The driving control unit 200 generates a data signal DATA based on the input image data IMG and outputs the data signal DATA to the data driving unit 500 .

[0054] The driving control part 200 generates the third control signal CONT3 for controlling the operation of the gamma reference voltage generating part 400 based on the input control signal CONT, and outputs the third control signal CONT3 to the gamma reference voltage generating part 400 .

[0055] The gate driver 300 generates a gate signal for driving the gate line GL in response to the first control signal CONT1 received from the driver control unit 200. The gate driver 300 outputs the gate signal to the gate line GL. For example, the gate driver 300 may sequentially output the gate signal to the gate lines GL. For example, the gate driver 300 may be integrated with the peripheral portion of the display panel 100. For example, the gate driver 300 may be mounted on the peripheral portion of the display panel 100.

[0056] The gamma reference voltage generator 400 generates gamma reference voltages VGREF in response to the third control signal CONT3 received from the driving control part 200. The gamma reference voltage generator 400 provides the gamma reference voltages VGREF to the data driving part 500. The gamma reference voltages VGREF have values corresponding to the respective data signals DATA.

[0057] In an embodiment of the present invention, the gamma reference voltage generating section 400 may be disposed in the driving control section 200 or in the data driving section 500 .

[0058] The data driving unit 500 receives the second control signal CONT2 and the data signal DATA from the driving control unit 200, and receives the gamma reference voltage VGREF from the gamma reference voltage generating unit 400. The data driving unit 500 converts the data signal DATA into an analog data voltage using the gamma reference voltage VGREF. The data driving unit 500 outputs the data voltage to the data line DL.

[0059] The power supply voltage generating unit 600 may generate a power supply voltage required to drive at least one of the display panel 100 , the driving control unit 200 , the gate driving unit 300 , the gamma reference voltage generating unit 400 , and the data driving unit 500 .

[0060] For example, the power voltage generator 600 generates a first power voltage ELVDD and a second power voltage ELVSS to be applied to the pixels P of the display panel 100, and outputs the first power voltage ELVDD and the second power voltage ELVSS to the display panel 100. The second power voltage ELVSS may be lower than the first power voltage ELVDD.

[0061] Figure 2 It shows Figure 1 The pixels P and Figure 1 1. A circuit diagram of a voltage sensing portion of a data driving portion 500. Figure 3is shown in the sensing period Figure 2 A timing diagram of the input / output signals of the pixel P and the voltage sensing unit.

[0062] Reference Figures 1 to 3 At least one of the pixels P of the display panel 100 may include: a first switching element T1, including a control electrode connected to the first node N1, an input electrode to which the first power voltage ELVDD is applied, and an output electrode connected to the second node N2; a second switching element T2, including a control electrode to which the first signal S1 is applied, an input electrode to which the first data voltage VDATA is applied, and an output electrode connected to the first node N1; a first light-emitting element OL, including a first electrode connected to the second node N2 and a second electrode to which the second power voltage ELVSS is applied; a third switching element T3, including a control electrode to which the second signal S2 is applied, an input electrode connected to the second node N2, and an output electrode connected to the third node N3; and a fourth switching element TD, including a control electrode to which the third signal STD is applied, an input electrode connected to the third node N3, and an output electrode connected to the sensing line SL.

[0063] The pixel P may further include a storage capacitor CST having a first electrode connected to the first node N1 and a second electrode connected to the second node N2. Also, a parasitic capacitance of the display panel 100 is denoted by CP.

[0064] The data driving part 500 may output a data voltage VDATA to the display panel 100. Also, the data driving part 500 may receive a sensing voltage VSENSE from the display panel 100. For example, the voltage sensing part of the data driving part 500 may receive the sensing voltage VSENSE.

[0065] The data driver 500 can output a data voltage VDATA to the display panel 100 during a driving period and receive a sensing voltage VSENSE from the display panel 100 during a sensing period. The sensing operation during the sensing period is used to obtain a threshold voltage compensation value to compensate for variations in the threshold voltages of switching elements of pixels in the display panel 100. This operation can be performed during the manufacturing process of the display device, but not during operation of the display device. Alternatively, the sensing operation can be performed during the initial operation period of the display panel 100. Alternatively, the sensing operation can be performed at predetermined intervals between the driving periods.

[0066] The data driving unit 500 may include: a first switch SW1 including a first end connected to the sensing line SL and a second end to which an initialization voltage VINIT is applied, and controlled by a first sensing signal SW1_S; and a second switch SW2 connected to the first end of the first switch SW1 and controlled by a second sensing signal SW2_S.

[0067] In this embodiment, the activation period of the third signal STD may overlap with the activation period of the first data voltage VDATA. Figure 2 As shown, in this embodiment, since the control electrode of the fourth switching element TD is connected to the input electrode of the second switching element T2, the activation period of the third signal STD can be the same as the activation period of the first data voltage VDATA. That is, the third signal STD is the same signal as the first data voltage VDATA. In the following description, the activation period of a "signal" or "data voltage" may refer to a period during which the "signal" or "data voltage" has a first level, while the deactivation period of a "signal" or "data voltage" may refer to a period during which the "signal" or "data voltage" has a second level lower than the first level. Furthermore, during the activation period of a "signal," the switching element controlled by the "signal" may be in a closed or conducting state, while during the deactivation period of the "signal," the switching element controlled by the "signal" may be in an open or cut-off state.

[0068] In the first period DU1 of the sensing period, the first signal S1, the second signal S2, the first data voltage VDATA, the third signal STD, and the first sensing signal SW1_S may be activated, and the second sensing signal SW2_S may be deactivated. For example, the first period DU1 may be named a delay period TDLY.

[0069] During the first period DU1, the initialization voltage VINIT is applied to the pixel. During the first period DU1, the initialization voltage VINIT may be applied to the output electrode of the first switching element T1, and the reference voltage VREF may be applied to the control electrode of the first switching element T1. For example, the first data voltage VDATA may be the reference voltage VREF.

[0070] In the second period DU2 after the first period DU1 of the sensing period, the first signal S1, the second signal S2, the first data voltage VDATA, the third signal STD, the first sensing signal SW1_S, and the second sensing signal SW2_S may be in an active state. For example, the second period DU2 may be named an initialization period TINIT.

[0071] During the second period DU2 , the initialization voltage VINIT is applied to the pixel, and during the second period DU2 , the level of the parasitic capacitance CP of the display panel 100 is initialized to the initialization voltage VINIT.

[0072] In the third period DU3 after the second period DU2 of the sensing period, the first signal S1, the second signal S2, the first data voltage VDATA, the third signal STD, and the second sensing signal SW2_S may be activated, and the first sensing signal SW1_S may be deactivated. For example, the third period DU3 may be named a sampling period TSAMPLE.

[0073] During the third period DU3 , the first switching element T1 operates as a source follower, and the sensing voltage VSENSE of the sensing line SL is charged to a value VREF−VTH(T1) obtained by subtracting the threshold voltage VTH(T1) of the first switching element T1 from the reference voltage VREF.

[0074] In a fourth period DU4 after the third period DU3 of the sensing period, the first signal S1, the second signal S2, the first data voltage VDATA, and the third signal STD may have active states, and the first sensing signal SW1_S and the second sensing signal SW2_S may have inactive states.

[0075] During the fourth period DU4 , the sensing voltage VSENSE may be sensed, and the threshold voltage VTH( T1 ) of the first switching element T1 may be determined based on the sensing voltage VSENSE.

[0076] Figure 4 is shown in the driving period Figure 2 A timing diagram of the input signals of the pixel and the voltage sensing unit.

[0077] Reference Figures 1 to 4 The driving control unit 200 may determine a threshold voltage VTH(T1) of the first switching element T1 of the pixel based on the sensing voltage VSENSE received from the sensing line SL, and compensate the data signal DATA based on the threshold voltage VTH(T1).

[0078] The driving control unit 200 may output the data signal DATA, in which the deviation of the threshold voltage is compensated, to the data driving unit 500 . The data driving unit 500 converts the data signal DATA and outputs the data voltage VDATA to the display panel 100 .

[0079] During the driving period, the first signal S1 may be a gate signal of the pixel P, and may be scan-driven in a manner matching a driving timing of the pixel P.

[0080] During the driving period, the first data voltage VDATA and the third signal STD may be data voltages of the pixel P and have values corresponding to the color scale of the pixel P.

[0081] During the driving period, the second signal S2 may be in an inactive state. During the driving period, the third switching element T3 is turned off by the inactive second signal S2. Therefore, during the driving period, the third switching element T3 and the fourth switching element TD do not affect the operation of the pixel P. Furthermore, during the driving period, the first sensing signal SW1_S and the second sensing signal SW2_S may be in an inactive state.

[0082] According to this embodiment, the pixel P includes a first sensing switch element T3 and a second sensing switch element TD connected in series with the first sensing switch element T3. The control signal STD of the second sensing switch element TD has an activation period that overlaps with the data voltage VDATA of the pixel P. This improves the accuracy of voltage sensing of the pixel P. Consequently, the compensation accuracy of the threshold voltage VTH(T1) of the switching element T1 of the pixel P can be improved, thereby improving the display quality of the display panel 100.

[0083] Figure 5 FIG. 1 is a circuit diagram illustrating a pixel P of a display panel 100 and a voltage sensing unit of a data driving unit 500 according to an embodiment of the present invention. Figure 6 is shown in the first sensing period Figure 5 A timing diagram of the input / output signals of the pixel P and the voltage sensing unit. Figure 7 is shown in the second sensing period Figure 5 A timing diagram of the input / output signals of the pixel P and the voltage sensing unit. Figure 8 is shown in the third sensing period Figure 5 A timing diagram of the input / output signals of the pixel P and the voltage sensing unit.

[0084] The display device according to this embodiment is similar to the pixel circuit. Figures 1 to 4 The display devices of the present invention are substantially the same, and therefore the same reference numerals are used for the same or similar components, and repeated descriptions are omitted.

[0085] Reference Figure 1 、 Figures 3 to 8The display device includes a display panel 100 and a display panel driving unit. The display panel driving unit includes a driving control unit 200, a gate driving unit 300, a gamma reference voltage generating unit 400, and a data driving unit 500. The display panel driving unit also includes a power supply voltage generating unit 600.

[0086] In this embodiment, the first pixel, the second pixel, and the third pixel of the display panel 100 may be connected to one sensing line SL.

[0087] The first pixel may include: a first switching element T1R, including a control electrode connected to the first node N1, an input electrode to which the first power supply voltage ELVDD is applied, and an output electrode connected to the second node N2; a second switching element T2R, including a control electrode to which the first signal S1 is applied, an input electrode to which the first data voltage VDATA[R] is applied, and an output electrode connected to the first node N1; a first light-emitting element OLR, including a first electrode connected to the second node N2 and a second electrode to which the second power supply voltage ELVSS is applied; a third switching element T3R, including a control electrode to which the second signal S2 is applied, an input electrode connected to the second node N2, and an output electrode connected to the third node N3; and a fourth switching element TDR, including a control electrode to which the third signal STD[R] is applied, an input electrode connected to the third node N3, and an output electrode connected to the sensing line SL.

[0088] The first pixel may further include a storage capacitor CSTR having a first electrode connected to the first node N1 and a second electrode connected to the second node N2.

[0089] The second pixel may include: a fifth switching element T1G, including a control electrode connected to the fourth node N4, an input electrode to which the first power supply voltage ELVDD is applied, and an output electrode connected to the fifth node N5; a sixth switching element T2G, including a control electrode to which the first signal S1 is applied, an input electrode to which the second data voltage VDATA[G] is applied, and an output electrode connected to the fourth node N4; a second light-emitting element OLG, including a first electrode connected to the fifth node N5 and a second electrode to which the second power supply voltage ELVSS is applied; a seventh switching element T3G, including a control electrode to which the second signal S2 is applied, an input electrode connected to the fifth node N5, and an output electrode connected to the sixth node N6; and an eighth switching element TDG, including a control electrode to which the fourth signal STD[G] is applied, an input electrode connected to the sixth node N6, and an output electrode connected to the sensing line SL.

[0090] The second pixel may further include a storage capacitor CSTG having a first electrode connected to the fourth node N4 and a second electrode connected to the fifth node N5.

[0091] The third pixel may include: a ninth switching element T1B, including a control electrode connected to the seventh node N7, an input electrode to which the first power supply voltage ELVDD is applied, and an output electrode connected to the eighth node N8; a tenth switching element T2B, including a control electrode to which the first signal S1 is applied, an input electrode to which the third data voltage VDATA[B] is applied, and an output electrode connected to the seventh node N7; a third light-emitting element OLB, including a first electrode connected to the eighth node N8 and a second electrode to which the second power supply voltage ELVSS is applied; an eleventh switching element T3B, including a control electrode to which the second signal S2 is applied, an input electrode connected to the eighth node N8, and an output electrode connected to the ninth node N9; and a twelfth switching element TDB, including a control electrode to which the fifth signal STD[B] is applied, an input electrode connected to the ninth node N9, and an output electrode connected to the sensing line SL.

[0092] The third pixel may further include a storage capacitor CSTB having a first electrode connected to the seventh node N7 and a second electrode connected to the eighth node N8.

[0093] During the sensing period, the first data voltage VDATA[R] may be a voltage for sensing the first pixel, the second data voltage VDATA[G] may be a voltage for sensing the second pixel, and the third data voltage VDATA[B] may be a voltage for sensing the third pixel. The first data voltage VDATA[R], the second data voltage VDATA[G], and the third data voltage VDATA[B] may have different phases (different activation periods) from each other.

[0094] During the driving period, the first data voltage VDATA[R] may be a voltage for color gradation display of the first pixel, the second data voltage VDATA[G] may be a voltage for color gradation display of the second pixel, and the third data voltage VDATA[B] may be a voltage for color gradation display of the third pixel.

[0095] The sensing period may have a first sensing period for sensing the sensing voltage VSENSE of the first pixel, a second sensing period for sensing the sensing voltage VSENSE of the second pixel, and a third sensing period for sensing the sensing voltage VSENSE of the third pixel.

[0096] exist Figure 6 During the first sensing period shown, the third signal STD[R] and the first data voltage VDATA[R] may have an activated state, the fourth signal STD[G] and the second data voltage VDATA[G] have an inactivated state, and the fifth signal STD[B] and the third data voltage VDATA[B] have an inactivated state. Figure 6 The first sensing period of operation is with reference to Figure 3 The operations during the sensing period are substantially the same.

[0097] exist Figure 7 During the second sensing period shown, the third signal STD[R] and the first data voltage VDATA[R] may have an inactive state, the fourth signal STD[G] and the second data voltage VDATA[G] have an active state, and the fifth signal STD[B] and the third data voltage VDATA[B] have an inactive state. Figure 7 The second sensing period of operation is with reference to Figure 3 The operations during the sensing period are substantially the same.

[0098] exist Figure 8 During the third sensing period shown, the third signal STD[R] and the first data voltage VDATA[R] may have an inactive state, the fourth signal STD[G] and the second data voltage VDATA[G] have an inactive state, and the fifth signal STD[B] and the third data voltage VDATA[B] have an active state. Figure 8 The operation of the third sensing period is compared with the reference Figure 3 The operations during the sensing period are substantially the same.

[0099] In this embodiment, the activation period of the third signal STD[R] may overlap with the activation period of the first data voltage VDATA[R], the activation period of the fourth signal STD[G] may overlap with the activation period of the second data voltage VDATA[G], and the activation period of the fifth signal STD[B] may overlap with the activation period of the third data voltage VDATA[B].

[0100] like Figure 5As shown, in this embodiment, since the control electrode of the fourth switching element TDR is connected to the input electrode of the second switching element T2R, the activation period of the third signal STD[R] can be the same as the activation period of the first data voltage VDATA[R]. Furthermore, since the control electrode of the eighth switching element TDG is connected to the input electrode of the sixth switching element T2G, the activation period of the fourth signal STD[G] can be the same as the activation period of the second data voltage VDATA[G]. Furthermore, since the control electrode of the twelfth switching element TDB is connected to the input electrode of the tenth switching element T2B, the activation period of the fifth signal STD[B] can be the same as the activation period of the third data voltage VDATA[B].

[0101] However, the active period of the third signal STD[R], the active period of the fourth signal STD[G], and the active period of the fifth signal STD[B] may not overlap with each other.

[0102] In this embodiment, the first light-emitting element OLR may present a first color, the second light-emitting element OLG may present a second color different from the first color, and the third light-emitting element OLB may present a third color different from the first and second colors. For example, the first color may be red, the second color may be green, and the third color may be blue.

[0103] According to this embodiment, the pixel includes first sensing switching elements T3R, T3G, and T3B, and second sensing switching elements TDR, TDG, and TDB connected in series with the first sensing switching elements T3R, T3G, and T3B. Furthermore, the control signals STD[R], STD[G], and STD[B] for the second sensing switching elements TDR, TDG, and TDB have activation periods that overlap with the pixel data voltages VDATA[R], VDATA[G], and VDATA[B]. This improves the accuracy of voltage sensing for the pixel. Consequently, the compensation accuracy of the threshold voltages VTH(T1R), VTH(T1G), and VTH(T1B) of the pixel switching elements T1R, T1G, and T1B can be improved, thereby improving the display quality of the display panel 100.

[0104] Figure 9 FIG. 1 is a circuit diagram illustrating a pixel P of a display panel 100 and a voltage sensing unit of a data driving unit 500 according to an embodiment of the present invention. Figure 10 is shown in the sensing period Figure 9 A timing diagram of the input signal of the pixel.

[0105] The display device according to this embodiment is similar to the pixel circuit. Figures 5 to 8 The display devices of the present invention are substantially the same, so the same figure marks are used for the same or similar components, and repeated descriptions are omitted.

[0106] Reference Figure 1 、 Figures 6 to 10 The display device includes a display panel 100 and a display panel driving unit. The display panel driving unit includes a driving control unit 200, a gate driving unit 300, a gamma reference voltage generating unit 400, and a data driving unit 500. The display panel driving unit also includes a power supply voltage generating unit 600.

[0107] In this embodiment, the first pixel, the second pixel, and the third pixel of the display panel 100 may be connected to one sensing line SL.

[0108] Reference Figure 9 ,and Figure 5 In contrast, in this embodiment, the control electrode of the fourth switching element TDR may not be connected to the input electrode of the second switching element T2R. Furthermore, the control electrode of the eighth switching element TDG may not be connected to the input electrode of the sixth switching element T2G. Furthermore, the control electrode of the twelfth switching element TDB may not be connected to the input electrode of the tenth switching element T2B.

[0109] The third signal STD[R] may be applied to the control electrode of the fourth switching element TDR, the fourth signal STD[G] may be applied to the control electrode of the eighth switching element TDG, and the fifth signal STD[B] may be applied to the control electrode of the twelfth switching element TDB. In this embodiment, the third signal STD[R] may be generated independently of the first data voltage VDATA[R], the fourth signal STD[G] may be generated independently of the second data voltage VDATA[G], and the fifth signal STD[B] may be generated independently of the third data voltage VDATA[B].

[0110] like Figure 10 As shown, in the first sensing period SENSE[R], the activation period of the third signal STD[R] can overlap with the activation period of the first data voltage VDATA[R], in the second sensing period SENSE[G], the activation period of the fourth signal STD[G] can overlap with the activation period of the second data voltage VDATA[G], and in the third sensing period SENSE[B], the activation period of the fifth signal STD[B] can overlap with the activation period of the third data voltage VDATA[B).

[0111] exist Figure 10 In the description, the case where the activation period of the third signal STD[R] is the same as the activation period of the first data voltage VDATA[R], the activation period of the fourth signal STD[G] is the same as the activation period of the second data voltage VDATA[G], and the activation period of the fifth signal STD[B] is the same as the activation period of the third data voltage VDATA[B] is taken as an example. However, the present invention is not limited to this. The activation period of the third signal STD[R] may partially overlap with the activation period of the first data voltage VDATA[R], the activation period of the fourth signal STD[G] may partially overlap with the activation period of the second data voltage VDATA[G], and the activation period of the fifth signal STD[B] may partially overlap with the activation period of the third data voltage VDATA[B].

[0112] Furthermore, when the third signal STD[R], the fourth signal STD[G], and the fifth signal STD[B] are formed independently of the first data voltage VDATA[R], the second data voltage VDATA[G], and the third data voltage VDATA[B], the third signal STD[R], the fourth signal STD[G], and the fifth signal STD[B] may be inactivated during the driving period.

[0113] According to this embodiment, the pixel includes first sensing switching elements T3R, T3G, and T3B, and second sensing switching elements TDR, TDG, and TDB connected in series with the first sensing switching elements T3R, T3G, and T3B. Furthermore, the control signals STD[R], STD[G], and STD[B] for the second sensing switching elements TDR, TDG, and TDB have activation periods that overlap with the pixel data voltages VDATA[R], VDATA[G], and VDATA[B]. This improves the accuracy of voltage sensing for the pixel. Consequently, the compensation accuracy of the threshold voltages VTH(T1R), VTH(T1G), and VTH(T1B) of the pixel switching elements T1R, T1G, and T1B can be improved, thereby improving the display quality of the display panel 100.

[0114] Industrial applicability

[0115] According to the pixel circuit and the display device including the pixel circuit of the present invention described above, the display quality of the display panel can be improved.

[0116] Although the above description has been made with reference to the embodiments, it will be understood by those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and technical scope of the present invention as described in the claims.

Claims

1. A pixel circuit, comprising: The first pixel, The first pixel includes: A first switching element includes a control electrode connected to the first node, an input electrode to which a first power supply voltage is applied, and an output electrode connected to the second node; a second switching element comprising a control electrode to which a first signal is applied, an input electrode to which a first data voltage is applied, and an output electrode connected to the first node; a first light emitting element including a first electrode connected to the second node and a second electrode to which a second power supply voltage is applied; a third switching element including a control electrode to which the second signal is applied, an input electrode connected to the second node, and an output electrode connected to a third node; and a fourth switching element including a control electrode to which a third signal is applied, an input electrode connected to the third node, and an output electrode connected to the sensing line; The third signal is the same as the first data voltage.

2. The pixel circuit according to claim 1, wherein: The control electrode of the fourth switching element is connected to the input electrode of the second switching element.

3. The pixel circuit according to claim 1, wherein: The pixel circuit further includes: a second pixel and a third pixel, Wherein, the second pixel includes: a fifth switching element comprising a control electrode connected to the fourth node, an input electrode to which the first power supply voltage is applied, and an output electrode connected to the fifth node; a sixth switching element including a control electrode to which the first signal is applied, an input electrode to which a second data voltage having a phase different from that of the first data voltage is applied, and an output electrode connected to the fourth node; a second light emitting element including a first electrode connected to the fifth node and a second electrode to which the second power supply voltage is applied; a seventh switching element including a control electrode to which the second signal is applied, an input electrode connected to the fifth node, and an output electrode connected to a sixth node; and an eighth switching element including a control electrode to which a fourth signal is applied, an input electrode connected to the sixth node, and an output electrode connected to the sensing line, Wherein, the third pixel includes: a ninth switching element comprising a control electrode connected to the seventh node, an input electrode to which the first power supply voltage is applied, and an output electrode connected to the eighth node; a tenth switching element including a control electrode to which the first signal is applied, an input electrode to which a third data voltage having a phase different from that of the first data voltage and the second data voltage is applied, and an output electrode connected to the seventh node; a third light-emitting element comprising a first electrode connected to the eighth node and a second electrode to which the second power supply voltage is applied; an eleventh switching element including a control electrode to which the second signal is applied, an input electrode connected to the eighth node, and an output electrode connected to a ninth node; and The twelfth switching element includes a control electrode to which the fifth signal is applied, an input electrode connected to the ninth node, and an output electrode connected to the sensing line.

4. The pixel circuit according to claim 3, wherein: The activation period of the fourth signal at least partially overlaps with the activation period of the second data voltage, An activation period of the fifth signal at least partially overlaps with an activation period of the third data voltage.

5. The pixel circuit according to claim 4, wherein: The active period of the third signal, the active period of the fourth signal, and the active period of the fifth signal do not overlap with each other.

6. The pixel circuit according to claim 3, wherein: The control electrode of the fourth switching element is connected to the input electrode of the second switching element, The control electrode of the eighth switching element is connected to the input electrode of the sixth switching element, The control electrode of the twelfth switching element is connected to the input electrode of the tenth switching element.

7. The pixel circuit according to claim 3, wherein: The first light emitting element presents a first color, The second light emitting element displays a second color different from the first color, The third light emitting element displays a third color different from the first color and the second color.

8. The pixel circuit according to claim 1, wherein: An activation period of the second signal at least partially overlaps with an activation period of the first data voltage.

9. A display device, characterized in that: include: A display panel comprising the pixel circuit according to any one of claims 1 to 8 and displaying an image; as well as a data driving unit that outputs a data voltage to the display panel and receives a sensing voltage from the display panel, The data driving unit includes: a first switch comprising a first end connected to the sensing line and a second end to which an initialization voltage is applied, and controlled by a first sensing signal; as well as The second switch is connected to the first end of the first switch and is controlled by a second sensing signal.

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