Pixel

Abstract

The present disclosure relates to a pixel. The pixel includes: a light-emitting diode; a first transistor electrically connected to a first driving power source and the light-emitting diode; a second transistor electrically connected to an electrode of the first transistor and a gate electrode of the first transistor; a third transistor electrically connected to the first transistor and an anode of the light-emitting diode; and a fourth transistor electrically connected to the anode of the light-emitting diode and a first power source, wherein a gate electrode of the second transistor and a gate electrode of the fourth transistor are connected to a first scan line.

Description

[0001] This application is a divisional application of a patent application with an application date of February 24, 2018, an application number of 201810156832.0, and a title of "Pixel and Organic Light-Emitting Display Device Having the Same". Technical Field

[0002] Aspects of the present disclosure relate to a pixel and an organic light-emitting display device having the pixel, and more particularly, to a pixel for displaying an image of a desired brightness and an organic light-emitting display device having the pixel. Background Art

[0003] With the development of information technology, the importance of a display device as a connection medium between a user and information has been emphasized. Accordingly, the use of display devices such as liquid crystal display devices and organic light-emitting display devices has increased.

[0004] An organic light-emitting display device in a display device displays an image by using an organic light-emitting diode that emits light by recombining electrons and holes. The organic light-emitting display device has advantages of a fast response speed and low power consumption.

[0005] The organic light-emitting display device includes pixels connected to data lines and scan lines. Each pixel generally includes an organic light-emitting diode and a driving transistor that controls the amount of current flowing into the organic light-emitting diode. The driving transistor controls the amount of current flowing from a first driving power supply through the organic light-emitting diode to a second driving power supply in response to a data signal. The organic light-emitting diode emits light of a predetermined brightness corresponding to the amount of current from the driving transistor.

[0006] Recently, a method of achieving high brightness by setting the voltage of the second driving power supply low or a method of reducing power consumption by driving the organic light-emitting display device at a low frequency has been used. However, when the second driving power supply is set low or the organic light-emitting display device is driven at a low frequency, a predetermined leakage current is generated from the gate electrode of the driving transistor. Since the voltage of the data signal does not remain constant during a single frame, an image of a desired brightness is not displayed. Summary of the Invention

[0007] Aspects of the present disclosure are directed to a pixel for displaying an image of a desired brightness and an organic light-emitting display device having the pixel.

[0008] According to an aspect of the present disclosure, a pixel is provided, including: an organic light emitting diode; a first transistor configured to control an amount of current flowing from a first driving power supply to a second driving power supply via the organic light emitting diode in response to a voltage of a first node; a storage capacitor connected between the first node and the first driving power supply; a second transistor connected between a data line and the first node and turned on when a scan signal is supplied to a first scan line; and an auxiliary transistor connected between the second transistor and the data line and turned on when a scan signal is supplied to a second scan line, wherein the second transistor and the auxiliary transistor have overlapping on-periods, and the second transistor is turned off before the auxiliary transistor is turned off.

[0009] The auxiliary transistor may be an N-type transistor.

[0010] The auxiliary transistor may be an oxide semiconductor transistor.

[0011] Each of the first transistor and the second transistor may be a P-type transistor.

[0012] Each of the first transistor and the second transistor may be a polysilicon semiconductor transistor.

[0013] The second transistor and the auxiliary transistor may be turned on simultaneously.

[0014] The pixel may further include a third transistor formed between the first driving power supply and the first transistor or between the first transistor and an anode electrode of the organic light emitting diode, and the third transistor is turned off when a light emission control signal is supplied to a light emission control line.

[0015] The on-period of the third transistor may not overlap with the on-period of the second transistor.

[0016] According to another aspect of the present disclosure, a pixel is provided, including: an organic light emitting diode; a first transistor connected between a first driving power supply connected to a second node and an anode electrode of the organic light emitting diode and configured to control an amount of current supplied from the first driving power supply to the organic light emitting diode in response to a voltage of the second node; a storage capacitor connected between the second node and the first driving power supply; a second transistor connected between a data line and the first node and turned on when a first scan signal is supplied to an i-th (i is a natural number) first scan line; a third transistor connected between a second electrode of the first transistor and the second node and turned on when the first scan signal is supplied; and an auxiliary transistor connected between the third transistor and the second electrode of the first transistor and turned on when a second scan signal is supplied to the i-th second scan line, wherein the third transistor and the auxiliary transistor have overlapping on-periods, and the third transistor is turned off before the auxiliary transistor is turned off.

[0017] The auxiliary transistor can be an N-type transistor.

[0018] The auxiliary transistor can be an oxide semiconductor transistor.

[0019] Each of the first transistor, the second transistor, and the third transistor can be a P-type transistor.

[0020] Each of the first transistor, the second transistor, and the third transistor can be a polysilicon semiconductor transistor.

[0021] The third transistor and the auxiliary transistor can be turned on simultaneously.

[0022] The pixel may further include: a fourth transistor connected between the second node and the first power supply and turned on when a scan signal is supplied to the i-th third scan line; and a fifth transistor connected between the anode of the organic light-emitting diode and the first power supply and turned on when a scan signal is supplied to the i-th fourth scan line.

[0023] Each of the fourth transistor and the fifth transistor can be a P-type transistor.

[0024] Each of the fourth transistor and the fifth transistor can be a polysilicon semiconductor transistor.

[0025] The i-th third scan line can be the (i - 1)-th first scan line, and the i-th fourth scan line can be the i-th first scan line.

[0026] Each of the fourth transistor and the fifth transistor can be an N-type transistor.

[0027] Each of the fourth transistor and the fifth transistor can be an oxide semiconductor transistor.

[0028] The i-th third scan line can be the (i - 1)-th second scan line, and the i-th fourth scan line can be the i-th second scan line.

[0029] The pixel may further include: a sixth transistor connected between the first driving power supply and the first node, where the sixth transistor is turned on except when a light emission control signal is supplied to the i-th light emission control line; and a seventh transistor connected between the second electrode of the first transistor and the anode of the organic light-emitting diode, and the seventh transistor is turned on and off simultaneously with the sixth transistor.

[0030] The conduction period of the sixth transistor may not overlap with the conduction period of the third transistor.

[0031] According to another aspect of the present disclosure, there is provided a pixel including: an organic light emitting diode; a first transistor connected between an anode electrode of the organic light emitting diode connected to a second node and a first driving power supply, and configured to control an amount of current supplied from the first driving power supply to the organic light emitting diode in response to a voltage of a first node; a storage capacitor connected between the first node and the second node; a second transistor connected between a data line and the first node, and turned on when a scan signal is supplied to a first scan line; and an auxiliary transistor connected between the second transistor and the data line, and turned on when a scan signal is supplied to a second scan line, wherein the second transistor and the auxiliary transistor have overlapping on periods, and the second transistor is turned off before the auxiliary transistor is turned off.

[0032] The auxiliary transistor may be an N-type transistor.

[0033] The auxiliary transistor may be an oxide semiconductor transistor.

[0034] Each of the first transistor and the second transistor may be an N-type transistor.

[0035] Each of the first transistor and the second transistor may be a polysilicon semiconductor transistor.

[0036] The second transistor and the auxiliary transistor may be turned on simultaneously.

[0037] The pixel may further include: a third transistor connected between the second node and a first power supply, and turned on when a scan signal is supplied to a third scan line; a fourth transistor connected between the first driving power supply and a first electrode of the first transistor, and turned off when a light emission control signal is supplied to a light emission control line; and a fifth transistor connected between a reference power supply and the first node and turned on when a scan signal is supplied to a fourth scan line.

[0038] Each of the third transistor and the fourth transistor may be an N-type polysilicon semiconductor transistor, and the fifth transistor may be an N-type oxide semiconductor transistor.

[0039] According to another aspect of the present disclosure, there is provided a pixel including: an organic light-emitting diode; a first transistor configured to control the amount of current flowing from a first driving power supply to a second driving power supply via the organic light-emitting diode in response to a voltage at a first node; a second transistor connected between the first node and a second electrode of the first transistor and turned on when a first scan signal is supplied to a first scan line; a storage capacitor connected between the first node and a second node; a third transistor connected between a data line and the second node and turned on when the first scan signal is supplied; and an auxiliary transistor connected between the data line and the third transistor and turned on when a second scan signal is supplied to a second scan line, wherein the third transistor and the auxiliary transistor have overlapping on periods, and the third transistor turns off before the auxiliary transistor turns off.

[0040] The auxiliary transistor may be an N-type transistor.

[0041] The auxiliary transistor may be an oxide semiconductor transistor.

[0042] Each of the first transistor, the second transistor, and the third transistor may be a P-type transistor.

[0043] Each of the first transistor, the second transistor, and the third transistor may be a polysilicon semiconductor transistor.

[0044] The third transistor and the auxiliary transistor may be turned on simultaneously.

[0045] The pixel may further include: a fourth transistor connected between the second node and a first power supply and turned off when an inverted light emission control signal is supplied to an inverted light emission control line; a fifth transistor connected between the first power supply and an anode electrode of the organic light-emitting diode and turned on when the first scan signal is supplied; and a sixth transistor connected between the first transistor and the anode electrode of the organic light-emitting diode and turned off when a light emission control signal is supplied to a light emission control line.

[0046] The fourth transistor and the sixth transistor may have overlapping on periods.

[0047] The on period of the fourth transistor may at least partially overlap with the on period of the second transistor.

[0048] The fourth transistor may be an N-type oxide semiconductor transistor, and each of the fifth transistor and the sixth transistor may be a P-type polysilicon semiconductor transistor.

[0049] According to another aspect of the present disclosure, there is provided a pixel including: a first transistor disposed on a current path from a first driving power supply via an organic light-emitting diode to a second driving power supply; and a second transistor and an auxiliary transistor connected in series on a leakage current path different from the current path, wherein the second transistor and the auxiliary transistor have overlapping conduction periods, and the second transistor turns off before the auxiliary transistor turns off.

[0050] The second transistor may be electrically connected to the gate electrode of the first transistor.

[0051] The auxiliary transistor may be an N-type transistor.

[0052] The auxiliary transistor may be an oxide semiconductor transistor.

[0053] The second transistor may be a polysilicon semiconductor transistor.

[0054] The second transistor and the auxiliary transistor may be turned on simultaneously.

[0055] According to an aspect of the present disclosure, there is provided an organic light-emitting display device including pixels connected to scan lines and data lines, wherein each pixel may include: a first transistor disposed on a current path from a first driving power supply via an organic light-emitting diode to a second driving power supply; and a second transistor and an auxiliary transistor connected in series on a leakage current path different from the current path, wherein the second transistor and the auxiliary transistor have overlapping conduction periods, and the second transistor turns off before the auxiliary transistor turns off.

[0056] The second transistor may be electrically connected to the gate electrode of the first transistor.

[0057] The auxiliary transistor may be an N-type transistor.

[0058] The auxiliary transistor may be an oxide semiconductor transistor.

[0059] The second transistor may be a polysilicon semiconductor transistor.

[0060] The second transistor and the auxiliary transistor may be turned on simultaneously.

[0061] According to an aspect of the present disclosure, there is provided an organic light-emitting display device including: a driving transistor and an organic light-emitting diode connected in series between a first driving power supply and a second driving power supply; a switching transistor and an auxiliary transistor connected in series between a data line and the driving transistor, and the auxiliary transistor is connected between the switching transistor and the data line. Wherein, the switching transistor and the auxiliary transistor may respectively include different active layers.

[0062] The auxiliary transistor may include an oxide semiconductor as an active layer.

[0063] The switching transistor may include polysilicon as an active layer.

[0064] The switching transistor and the auxiliary transistor may be turned on simultaneously, and the switching transistor may be turned off before the auxiliary transistor is turned off. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is a schematic diagram showing a display device according to an embodiment of the present disclosure;

[0066] Figure 2 is a view showing the connection between transistors for minimizing leakage current according to an embodiment of the present disclosure;

[0067] Figure 3 is a waveform diagram showing an embodiment of a driving method of the Figure 2 transistor;

[0068] Figure 4 is a view showing a pixel according to an embodiment of the present disclosure;

[0069] Figure 5 is a waveform diagram showing an embodiment of a driving method of the Figure 4 pixel shown in;

[0070] Figure 6A and Figure 6B is a view showing a pixel according to another embodiment of the present disclosure;

[0071] Figure 7 is a waveform diagram showing an embodiment of a driving method of the Figure 6A and Figure 6B pixel shown in;

[0072] Figure 8 is a view showing a pixel according to another embodiment of the present disclosure;

[0073] Figure 9 is a waveform diagram showing an embodiment of a driving method of the Figure 8 pixel shown in;

[0074] Figure 10 is a view showing a pixel according to another embodiment of the present disclosure;

[0075] Figure 11 is a waveform diagram showing an embodiment of a driving method of the Figure 10 pixel shown in;

[0076] Figure 12 is a view showing a pixel according to another embodiment of the present disclosure;

[0077] Figure 13 is a waveform diagram showing an embodiment of a driving method of theFigure 12 The waveform diagram of an embodiment of the driving method of the pixel shown in;

[0078] Figure 14 is a view showing a pixel according to another embodiment of the present disclosure;

[0079] Figure 15 is showing Figure 14 The waveform diagram of an embodiment of the driving method of the pixel shown in;

[0080] Figure 16 is a view showing a pixel according to another embodiment of the present disclosure;

[0081] Figure 17 is showing Figure 16 The waveform diagram of an embodiment of the driving method of the pixel shown in;

[0082] Figure 18 is a view showing a pixel according to another embodiment of the present disclosure; and

[0083] Figure 19 is showing Figure 18 The waveform diagram of an embodiment of the driving method of the pixel shown in. Detailed Description of the Invention

[0084] Hereinafter, embodiments of the present disclosure and other topics necessary for those skilled in the art to understand the content of the present disclosure will be described in detail with reference to the accompanying drawings. However, we note that the present invention can be implemented in different other forms and should not be construed as limited to the embodiments set forth herein.

[0085] That is, the present disclosure is not limited to the embodiments described herein, but can be implemented in other forms. It should also be noted that in this specification, "coupling and its variations" not only refer to one component being directly coupled to another component, but also refer to one component being indirectly coupled to another component through an intermediate component. In addition, in the drawings, the same or similar constituent elements are shown in different drawings, but are represented by the same reference numerals and signs as much as possible.

[0086] Figure 1 is a schematic diagram showing a display device according to an embodiment of the present disclosure.

[0087] Referring to Figure 1 , a display device according to an embodiment of the present disclosure may include a pixel region 100, a scan driver 110, a data driver 120, a light emission driver 130, a timing controller 140, and a host system 150.

[0088] The host system 150 can supply image data RGB to the timing controller 140 through a predetermined interface. In addition, the host system 150 can supply timing signals Vsync, Hsync, DE, and CLK to the timing controller 140.

[0089] The timing controller 140 can generate a scan driving control signal SCS, a data driving control signal DCS, and a light emitting driving control signal ECS based on the image data RGB output from the host system 150 and the timing signals including the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the data enable signal DE, and the clock signal CLK. The scan driving control signal SCS generated by the timing controller 140 can be supplied to the scan driver 110, the data driving control signal DCS can be supplied to the data driver 120, and the light emitting driving control signal ECS can be supplied to the light emitting driver 130. In addition, the timing controller 140 can rearrange the image data RGB supplied from the host system 150 and supply the rearranged image data RGB to the data driver 120.

[0090] The scan driving control signal SCS can include a scan start pulse and a clock signal. The scan start pulse can control the first timing of the scan signal. The clock signal can be used to shift the scan start pulse.

[0091] The data driving control signal DCS can include a source start pulse and a clock signal. The source start pulse can control the sampling start point of the data. The clock signal can be used to control the sampling operation.

[0092] The light emitting driving control signal ECS can include a light emitting start pulse and a clock signal. The light emitting start pulse can control the first timing of the light emitting control signal. The clock signal can be used to shift the light emitting start pulse.

[0093] The scan driver 110 can supply a scan signal to the scan line S in response to the scan driving control signal SCS. For example, the scan driver 110 can sequentially supply the scan signal to the scan line S. When the scan signal is sequentially supplied to the scan line S, pixels PXL can be selected in units of horizontal lines. The scan signal can be set to a gate-on voltage so that the transistors included in the pixels PXL can be turned on.

[0094] The data driver 120 can supply a data signal to the data line D in response to the data driving control signal DCS. The data signal supplied to the data line D can be supplied to the pixels PXL selected by the scan signal. The data driver 120 can supply the data signal to the data line D in synchronization with the scan signal.

[0095] The light-emitting driver 130 may supply a light-emitting control signal to the light-emitting control line E in response to the light-emitting drive control signal ECS. For example, the light-emitting driver 130 may sequentially supply the light-emitting control signal to the light-emitting control line E. When the light-emitting control signal is sequentially supplied to the light-emitting control line E, the pixel PXL connected to the selected light-emitting control line E does not emit light. The light-emitting control signal may be set to a gate cut-off voltage so that the transistor included in the pixel PXL may be cut off.

[0096] In addition, the light-emitting control signal supplied to the i-th (i is a natural number) light-emitting control line Ei may overlap with the scan signal supplied to the i-th scan line Si. During a period when the data signal is supplied to the pixel PXL provided on the i-th horizontal line, the pixel PXL connected to the i-th horizontal line may be set to a non-emission state, thereby preventing the pixel PXL from undesirably generating light.

[0097] Figure 1 It is shown that the scan driver 110 and the light-emitting driver 130 are separate drivers from each other, but the present disclosure is not limited thereto. For example, the scan driver 110 and the light-emitting driver 130 may be formed as a single driver. In addition, the scan driver 110 and / or the light-emitting driver 130 may be formed on a substrate by performing a thin-film process. In addition, the scan driver 110 and / or the light-emitting driver 130 may be provided on both sides where the pixel region 100 is disposed between the scan driver 110 and the light-emitting driver 130.

[0098] The pixels PXL in the pixel region 100 may be respectively connected to the data line D, the scan line S, and the light-emitting control line E. The pixels PXL may be supplied with a first driving power supply ELVDD and a second driving power supply ELVSS from outside the pixel region 100 (for example, a power supply (not shown)).

[0099] When the scan signal is supplied to the scan line S to which each pixel PXL is connected, each pixel PXL may be selected and each pixel PXL is supplied with a data signal from the data line D. The pixel PXL supplied with the data signal may control the amount of current flowing from the first driving power supply ELVDD via an organic light-emitting diode (not shown) to the second driving power supply ELVSS in response to the data signal. The organic light-emitting diode may generate light of a predetermined brightness corresponding to the current flowing through the organic light-emitting diode. In addition, the first driving power supply ELVDD may be set to a voltage higher than the second driving power supply ELVSS.

[0100] Figure 1 It is shown that each pixel PXL is connected to one scan line S, one data line D, and one light-emitting control line E, but the present disclosure is not limited thereto. In other words, the signal lines S, D, and E connected to the pixel PXL may vary according to the pixel structure of the pixel PXL.

[0101] In addition, the pixel PXL can be connected only to the scan line S and the data line D. The emission control line E and the emission driver 130 for driving the emission control line E can be omitted.

[0102] Figure 2 is a view showing the connection relationship between transistors for minimizing leakage current according to an embodiment of the present disclosure. Figure 2 The transistors shown in can be included in the pixel PXL and are provided on the leakage path of the current.

[0103] Referring to Figure 2 , an oxide semiconductor transistor M(O) and a polysilicon semiconductor transistor M(P) can be formed on the leakage path of the pixel PXL according to an embodiment of the present disclosure. For example, a polysilicon semiconductor transistor M(P) can be formed to be connected to the gate electrode of the driving transistor MD, and an oxide semiconductor transistor M(O) can be formed to be connected to the polysilicon semiconductor transistor M(P).

[0104] The oxide semiconductor transistor M(O) can include a gate electrode, a source electrode, and a drain electrode, and an active layer can be formed of an oxide semiconductor. The oxide semiconductor can be amorphous or crystalline. The oxide semiconductor transistor M(O) can be formed of an N-type transistor.

[0105] The oxide semiconductor transistor M(O) can be formed by performing a low-temperature process and has a lower electron mobility than the polysilicon semiconductor transistor M(P). The oxide semiconductor transistor M(O) can have excellent off-current characteristics.

[0106] The polysilicon semiconductor transistor M(P) can include a gate electrode, a source electrode, and a drain electrode, and its active layer can be formed of polysilicon. For example, the polysilicon semiconductor transistor M(P) can be set as a low-temperature polysilicon (LTPS) transistor. The polysilicon semiconductor transistor M(P) can be formed of a P-type transistor or an N-type transistor. However, for ease of explanation, Figure 2 shows that the polysilicon semiconductor transistor M(P) can be set as a P-type transistor. The polysilicon semiconductor transistor M(P) can have a high electron mobility and thus has fast driving characteristics.

[0107] The first electrode of the polysilicon semiconductor transistor M(P) can be connected to the gate electrode of the driving transistor MD, and the second electrode of the polysilicon semiconductor transistor M(P) can be connected to the first electrode of the oxide semiconductor transistor M(O). In addition, the gate electrode of the polysilicon semiconductor transistor M(P) can be connected to the first scan line S1. When the first scan signal is supplied to the first scan line S1, the polysilicon semiconductor transistor M(P) can be turned on.

[0108] The first electrode of the oxide semiconductor transistor M(O) can be connected to the second electrode of the polysilicon semiconductor transistor M(P). In addition, the gate electrode of the oxide semiconductor transistor M(O) can be connected to the second scan line S2. When a second scan signal is supplied to the second scan line S2, the oxide semiconductor transistor M(O) can be turned on.

[0109] The polysilicon semiconductor transistor M(P) and the oxide semiconductor transistor M(O) can have overlapping on periods, and the polysilicon semiconductor transistor M(P) can be turned off before the oxide semiconductor transistor M(O) is turned off.

[0110] The first scan signal supplied to the first scan line S1 and the second scan signal supplied to the second scan line S2 can be supplied simultaneously, as Figure 3 shown. The polysilicon semiconductor transistor M(P) and the oxide semiconductor transistor M(O) can be turned on simultaneously. When the oxide semiconductor transistor M(O) and the polysilicon semiconductor transistor M(P) are turned on simultaneously, fast driving characteristics of the polysilicon semiconductor transistor M(P) can be ensured.

[0111] After the first scan signal supplied to the first scan line S1 drops, the second scan signal supplied to the second scan line S2 can drop. After the polysilicon semiconductor transistor M(P) is turned off, the oxide semiconductor transistor M(O) can be turned off. When the polysilicon semiconductor transistor M(P) is turned off before the oxide semiconductor transistor M(O), the voltage change of the gate electrode of the driving transistor MD can be minimized, thereby preventing image quality degradation.

[0112] More specifically, the capacitance of the channel capacitor of the oxide semiconductor transistor M(O) can be set to be greater than the capacitance of the channel capacitor of the polysilicon semiconductor transistor M(P). Therefore, when the polysilicon semiconductor transistor M(P) and the oxide semiconductor transistor M(O) are both turned off, the voltage of the gate electrode of the driving transistor MD fluctuates by a predetermined voltage, thus degrading the image quality.

[0113] In contrast, according to an embodiment of the present disclosure, when the oxide semiconductor transistor M(O) is turned off after the polysilicon semiconductor transistor M(P) connected to the gate electrode of the driving transistor MD is turned off, the voltage of the gate electrode of the driving transistor MD can be prevented from being fluctuated by the channel capacitor of the oxide semiconductor transistor M(O). In addition, when the oxide semiconductor transistor M(O) is turned off, the leakage current flowing through the leakage path can be minimized.

[0114] That is, according to an embodiment of the present disclosure, the oxide semiconductor transistor M(O) and the polysilicon semiconductor transistor M(P) can form a leakage path of the pixel PXL, and the leakage current flowing through the leakage path can be minimized by using the oxide semiconductor transistor M(O). When the leakage current flowing through the leakage path is minimized, an image with a desired brightness can be displayed in the pixel PXL.

[0115] In addition, by turning off the oxide semiconductor transistor M(O) after turning off the polysilicon semiconductor transistor M(P) connected to the gate electrode of the driving transistor MD, the voltage change of the gate electrode of the driving transistor MD can be minimized.

[0116] Figure 4 is a view showing a pixel according to an embodiment of the present disclosure. For ease of explanation, Figure 4 it is shown that the pixel PXL is provided on the i-th horizontal line and connected to the m-th (m is a natural number) data line Dm.

[0117] Referring to Figure 4 , the pixel PXL according to an embodiment of the present disclosure may include an organic light emitting diode OLED and a pixel circuit 2001 that controls the amount of current supplied to the organic light emitting diode OLED.

[0118] The anode electrode of the organic light emitting diode OLED may be connected to the pixel circuit 2001, and the cathode electrode of the organic light emitting diode OLED may be connected to the second driving power supply ELVSS. The organic light emitting diode OLED may generate light with a predetermined brightness corresponding to the amount of current supplied from the pixel circuit 2001.

[0119] The pixel circuit 2001 may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light emitting diode OLED in response to a data signal. The pixel circuit 2001 may include a first transistor M1, a second transistor M2, an auxiliary transistor MS, and a storage capacitor Cst.

[0120] The first electrode of the first transistor M1 (driving transistor) may be connected to the first driving power supply ELVDD, and the second electrode of the first transistor M1 may be connected to the anode electrode of the organic light emitting diode OLED. In addition, the gate electrode of the first transistor M1 may be connected to the first node N1. The first transistor M1 may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light emitting diode OLED in response to the voltage of the first node N1.

[0121] The second transistor M2 (e.g., a switching transistor) may be connected between the first node N1 and the auxiliary transistor MS. In addition, the gate electrode of the second transistor M2 may be connected to the i-th first scan line S1i. When the first scan signal is supplied to the i-th first scan line S1i, the second transistor M2 may be turned on, thereby electrically connecting the auxiliary transistor MS and the first node N1.

[0122] The auxiliary transistor MS may be connected between the m-th data line Dm and the second transistor M2. In addition, the gate electrode of the auxiliary transistor MS may be connected to the i-th second scan line S2i. When the second scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS may be turned on, thereby electrically connecting the m-th data line Dm and the second transistor M2.

[0123] The storage capacitor Cst may be connected between the first node N1 and the first driving power supply ELVDD. The storage capacitor Cst may store a voltage corresponding to the data signal.

[0124] Each of the first transistor M1 and the second transistor M2 may be formed of a p-type polysilicon semiconductor transistor, and the auxiliary transistor MS may be formed of an n-type oxide semiconductor transistor. When the first transistor M1 and the second transistor M2 are formed of polysilicon semiconductor transistors, fast driving characteristics can be ensured. When the auxiliary transistor MS is formed of an oxide semiconductor transistor, the leakage current between the m-th data line Dm and the first node N1 can be minimized, so that the pixel PXL can display an image with a desired luminance.

[0125] Figure 5 is a waveform diagram showing Figure 4 an embodiment of a driving method of the pixel shown in

[0126] Referring to Figure 5 , the first scan signal may be supplied to the i-th first scan line S1i, and the second scan signal may be supplied to the i-th second scan line S2i. The first scan signal and the second scan signal may be supplied simultaneously.

[0127] When the first scan signal is supplied to the i-th first scan line S1i, the second transistor M2 may be turned on. When the second scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS may be turned on.

[0128] When the auxiliary transistor MS and the second transistor M2 are turned on, the m-th data line Dm and the first node N1 may be electrically connected, so that the data signal supplied to the m-th data line Dm may be supplied to the first node N1 via the auxiliary transistor MS and the second transistor M2. The storage capacitor Cst may store a voltage corresponding to the data signal.

[0129] Thereafter, the first scan signal supplied to the i-th first scan line S1i may fall, so that the second transistor M2 may be turned off. After the second transistor M2 is turned off, the second scan signal supplied to the i-th second scan line S2i may fall, and thus the auxiliary transistor MS may be turned off. Since the second transistor M2 is set to the off state, the voltage of the first node N1 can be prevented from being changed by the channel capacitor of the auxiliary transistor MS formed of an oxide semiconductor transistor.

[0130] After the auxiliary transistor MS is turned off, the first transistor M1 may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light-emitting diode OLED in response to the voltage of the first node N1. The organic light-emitting diode OLED may generate light of a predetermined luminance corresponding to the amount of current supplied from the first transistor M1.

[0131] In addition, when the organic light-emitting diode OLED emits light, the auxiliary transistor MS may be set to the off state. When the auxiliary transistor MS formed of an oxide semiconductor transistor is turned off, the leakage current between the m-th data line Dm and the first node N1 can be minimized, thereby displaying an image of a desired luminance.

[0132] Figure 6A and Figure 6B is a view showing a pixel according to another embodiment of the present disclosure. In the Figure 6A and Figure 6B description, components the same as those in Figure 4 will be given the same reference numerals, and their detailed descriptions will be omitted.

[0133] Referring to Figure 6A a pixel PXL according to another embodiment of the present disclosure may include an organic light-emitting diode OLED and a pixel circuit 2001' for controlling the amount of current supplied to the organic light-emitting diode OLED.

[0134] The anodic electrode of the organic light-emitting diode OLED may be connected to the pixel circuit 2001', and the cathodic electrode of the organic light-emitting diode OLED may be connected to the second driving power supply ELVSS. The organic light-emitting diode OLED may generate light of a predetermined luminance corresponding to the amount of current supplied from the pixel circuit 2001'.

[0135] The pixel circuit 2001' may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light-emitting diode OLED in response to a data signal. The pixel circuit 2001' may include a first transistor M1, a second transistor M2, a third transistor M3, an auxiliary transistor MS, and a storage capacitor Cst.

[0136] The third transistor M3 may be disposed between the first driving power supply ELVDD and the first electrode of the first transistor M1. In addition, a gate electrode of the third transistor M3 may be connected to the i-th light emission control line Ei. When a light emission control signal is supplied to the i-th light emission control line Ei, the third transistor M3 may be turned off, and when the light emission control signal is not supplied to the i-th light emission control line Ei, the third transistor M3 may be turned on.

[0137] The light emission control signal supplied to the i-th light emission control line Ei may overlap with the first scan signal supplied to the i-th first scan line S1i and the second scan signal supplied to the i-th second scan line S2i. Accordingly, when a voltage corresponding to a data signal is stored in the storage capacitor Cst, the third transistor M3 may be turned off, thereby preventing the organic light emitting diode OLED from emitting light unnecessarily.

[0138] In addition, the first scan signal and the second scan signal may be set to a gate-on voltage. For example, the first scan signal supplied to the i-th first scan line S1i may be set to a low voltage as the gate-on voltage so that the second transistor M2 may be turned on. In addition, when the first scan signal is not supplied to the i-th first scan line S1i, a high voltage as a gate-off voltage may be supplied to the i-th first scan line S1i.

[0139] In a similar manner, the second scan signal supplied to the i-th second scan line S2i may be set to a high voltage as the gate-on voltage so that the auxiliary transistor MS may be turned on. In addition, when the second scan signal is not supplied to the i-th second scan line S2i, a low voltage as a gate-off voltage may be supplied to the i-th second scan line S2i.

[0140] In addition, the light emission control signal may be set to a gate-off voltage. The light emission control signal supplied to the i-th light emission control line Ei may be set to a high voltage as the gate-off voltage so that the third transistor M3 may be turned off. In addition, when the light emission control signal is not supplied to the i-th light emission control line Ei, a low voltage as a gate-on voltage may be supplied to the i-th light emission control line Ei.

[0141] Refer to Figure 6B According to another embodiment of the present disclosure, a pixel PXL may include an organic light emitting diode OLED and a pixel circuit 2001' that controls an amount of current supplied to the organic light emitting diode OLED.

[0142] The anode of the organic light-emitting diode (OLED) can be connected to the pixel circuit 2001', and the cathode of the OLED can be connected to the second driving power supply ELVSS. The OLED can generate light of a predetermined brightness corresponding to the amount of current supplied from the pixel circuit 2001'.

[0143] The pixel circuit 2001' can control the amount of current flowing from the first driving power supply ELVDD, via the OLED, to the second driving power supply ELVSS in response to a data signal. The pixel circuit 2001' can include first to third transistors M1 to M3, an auxiliary transistor MS, and a storage capacitor Cst.

[0144] The third transistor M3 can be connected between the second electrode of the first transistor M1 and the anode of the OLED. In addition, the gate electrode of the third transistor M3 can be connected to the i-th light emission control line Ei. When a light emission control signal is supplied to the i-th light emission control line Ei, the third transistor M3 can be turned off, and when the light emission control signal is not supplied to the i-th light emission control line Ei, the third transistor M3 can be turned on.

[0145] The light emission control signal supplied to the i-th light emission control line Ei can overlap with the first scan signal supplied to the i-th first scan line S1i and the second scan signal supplied to the i-th second scan line S2i, as Figure 7 shown. Thus, when a voltage corresponding to the data signal is stored in the storage capacitor Cst, the third transistor M3 can be turned off, thereby preventing the OLED from emitting light unnecessarily.

[0146] Figure 8 is a view showing a pixel according to another embodiment of the present disclosure. For ease of explanation, Figure 8 shows a pixel PXL provided on the i-th horizontal line and connected to the m-th data line Dm. In the Figure 8 description, the auxiliary transistor MS having the same function as Figure 4 will be given the same reference numeral.

[0147] Referring to Figure 8 , a pixel PXL according to another embodiment of the present disclosure can include an OLED and a pixel circuit 2002 that controls the amount of current supplied to the OLED.

[0148] The anode of the OLED can be connected to the pixel circuit 2002, and the cathode of the OLED can be connected to the second driving power supply ELVSS. The OLED can generate light of a predetermined brightness corresponding to the amount of current supplied from the pixel circuit 2002.

[0149] The pixel circuit 2002 can control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light-emitting diode OLED in response to a data signal. The pixel circuit 2002 can include a first transistor M1', a second transistor M2', an auxiliary transistor MS, and a storage capacitor Cst'.

[0150] A first electrode of the first transistor M1' (driving transistor) can be connected to the first driving power supply ELVDD, and a second electrode of the first transistor M1' can be connected to the anode electrode of the organic light-emitting diode OLED. In addition, a gate electrode of the first transistor M1' can be connected to the first node N1'. The first transistor M1' can control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light-emitting diode OLED in response to the voltage of the first node N1'.

[0151] The second transistor M2' can be connected between the first node N1' and the auxiliary transistor MS. In addition, a gate electrode of the second transistor M2' can be connected to the i-th first scan line S1i. When a first scan signal is supplied to the i-th first scan line S1i, the second transistor M2' can be turned on to electrically connect the auxiliary transistor MS and the first node N1'.

[0152] The auxiliary transistor MS can be connected between the m-th data line Dm and the second transistor M2'. In addition, a gate electrode of the auxiliary transistor MS can be connected to the i-th second scan line S2i. When a scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS can be turned on to electrically connect the m-th data line Dm and the second transistor M2'.

[0153] The storage capacitor Cst' can be connected between the first node N1' and the anode electrode of the organic light-emitting diode OLED (i.e., the second node N2). The storage capacitor Cst' can store a voltage corresponding to the data signal.

[0154] Each of the first transistor M1' and the second transistor M2' can be formed of an N-type polysilicon semiconductor transistor, and the auxiliary transistor MS can be formed of an N-type oxide semiconductor transistor. When the first transistor M1' and the second transistor M2' are formed of polysilicon semiconductor transistors, fast driving characteristics can be ensured. When the auxiliary transistor MS is formed of an oxide semiconductor transistor, the leakage current between the m-th data line Dm and the first node N1' can be minimized, so that the pixel PXL can display an image with a desired brightness.

[0155] Figure 8 The pixel PXL shown in Figure 4The difference of the pixel PXL shown is that the first transistor M1' and the second transistor M2' are N-type transistors. However, Figure 8 the pixel PXL shown in Figure 4 and the pixel PXL shown in

[0156] Figure 9 basically perform the same operations. Figure 8 is a waveform diagram showing an embodiment of a driving method of the pixel shown in

[0157] Referring to Figure 9 , the first scan signal may be supplied to the i-th first scan line S1i, and the second scan signal may be supplied to the i-th second scan line S2i. The first scan signal and the second scan signal may be supplied simultaneously.

[0158] When the first scan signal is supplied to the i-th first scan line S1i, the second transistor M2' may be turned on. When the second scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS may be turned on.

[0159] When the auxiliary transistor MS and the second transistor M2' are turned on, the m-th data line Dm and the first node N1' may be electrically connected. The data signal supplied to the m-th data line Dm may be supplied to the first node N1' via the auxiliary transistor MS and the second transistor M2'. The storage capacitor Cst' may store the voltage corresponding to the data signal.

[0160] Thereafter, the first scan signal supplied to the i-th first scan line S1i may fall, so the second transistor M2' may be turned off. After the second transistor M2' is turned off, the second scan signal supplied to the i-th second scan line S2i may fall, so that the auxiliary transistor MS may be turned off. Since the second transistor M2' is set to the off state, the voltage of the first node N1' can be prevented from being changed by the channel capacitor of the auxiliary transistor MS formed of an oxide semiconductor transistor.

[0161] After the auxiliary transistor MS is turned off, the first transistor M1' may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light-emitting diode OLED in response to the voltage of the first node N1'. As a result, the organic light-emitting diode OLED may generate light of a predetermined brightness corresponding to the amount of current supplied from the first transistor M1'.

[0162] In addition, when the organic light-emitting diode OLED emits light, the auxiliary transistor MS may be set to the off state. When the auxiliary transistor MS formed of an oxide semiconductor transistor is turned off, the leakage current between the m-th data line Dm and the first node N1' can be minimized, thereby displaying an image of a desired brightness.

[0163] Figure 10 is a view showing a pixel according to another embodiment of the present disclosure. In Figure 10 the description of, the same reference numerals will be given to the components that are the same as the components of Figure 8 and their detailed description will be omitted.

[0164] Referring to Figure 10 , a pixel PXL according to another embodiment of the present disclosure may include an organic light emitting diode OLED and a pixel circuit 2002' that controls the amount of current supplied to the organic light emitting diode OLED.

[0165] The anode electrode of the organic light emitting diode OLED may be connected to the pixel circuit 2002', and the cathode electrode of the organic light emitting diode OLED may be connected to the second driving power supply ELVSS. The organic light emitting diode OLED may generate light of a predetermined brightness corresponding to the amount of current supplied from the pixel circuit 2002'.

[0166] The pixel circuit 2002' may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light emitting diode OLED in response to a data signal. The pixel circuit 2002' may include a first transistor M1', a second transistor M2', a third transistor M3', an auxiliary transistor MS, and a storage capacitor Cst'.

[0167] The third transistor M3' may be disposed between the first driving power supply ELVDD and the first electrode of the first transistor M1'. In addition, the gate electrode of the third transistor M3' may be connected to the i-th light emission control line Ei. When a light emission control signal is supplied to the i-th light emission control line Ei, the third transistor M3' may be turned off, and when a light emission control signal is not supplied to the i-th light emission control line Ei, the third transistor M3' may be turned on.

[0168] The light emission control signal supplied to the i-th light emission control line Ei may overlap with the first scan signal supplied to the i-th first scan line S1i and the second scan signal supplied to the i-th second scan line S2i, as Figure 11 shown. Accordingly, when a voltage corresponding to the data signal is stored in the storage capacitor Cst', the third transistor M3' may be turned off, thereby preventing the organic light emitting diode OLED from emitting light unnecessarily.

[0169] Figure 12 is a view showing a pixel PXL according to another embodiment of the present disclosure. For ease of explanation, Figure 12 a pixel PXL disposed on the i-th horizontal line and connected to the m-th data line Dm is shown.

[0170] Reference Figure 12 Figure 12 , a pixel PXL according to another embodiment of the present disclosure may include an organic light emitting diode OLED and a pixel circuit 2003 that controls the amount of current supplied to the organic light emitting diode OLED.

[0171] The anode electrode of the organic light emitting diode OLED may be connected to the pixel circuit 2003, and the cathode electrode of the organic light emitting diode OLED may be connected to the second driving power supply ELVSS. The organic light emitting diode OLED may generate light of a predetermined brightness corresponding to the amount of current supplied from the pixel circuit 2003.

[0172] The pixel circuit 2003 may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light emitting diode OLED in response to a data signal. The pixel circuit 2003 may include an eleventh transistor M11, a twelfth transistor M12, a thirteenth transistor M13, a fourteenth transistor M14, a fifteenth transistor M15, a sixteenth transistor M16, a seventeenth transistor M17, an auxiliary transistor MS11, and a storage capacitor Cst.

[0173] The first electrode of the eleventh transistor M11 (driving transistor) may be connected to the eleventh node N11, and the second electrode of the eleventh transistor M11 may be connected to the anode electrode of the organic light emitting diode OLED via the seventeenth transistor M17. In addition, the gate electrode of the eleventh transistor M11 may be connected to the twelfth node N12. The eleventh transistor M11 may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light emitting diode OLED in response to the voltage of the twelfth node N12. The first driving power supply ELVDD may be set to a voltage higher than the second driving power supply ELVSS.

[0174] The twelfth transistor M12 may be connected between the m-th data line Dm and the eleventh node N11. In addition, the gate electrode of the twelfth transistor M12 may be connected to the i-th first scan line S1i. When the first scan signal is supplied to the i-th first scan line S1i, the twelfth transistor M12 may be turned on to electrically connect the m-th data line Dm and the eleventh node N11.

[0175] The thirteenth transistor M13 may be connected between the twelfth node N12 and the second electrode of the eleventh transistor M11 through the auxiliary transistor MS11. In addition, the gate electrode of the thirteenth transistor M13 may be connected to the i-th first scan line S1i. When the first scan signal is supplied to the i-th first scan line S1i, the thirteenth transistor M13 may be turned on.

[0176] The auxiliary transistor MS11 may be connected between the thirteenth transistor M13 and the second electrode of the eleventh transistor M11. In addition, the gate electrode of the auxiliary transistor MS may be connected to the i-th second scan line S2i. When the second scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS11 may be turned on. The auxiliary transistor MS11 may be formed of an N-type oxide semiconductor transistor.

[0177] The fourteenth transistor M14 may be connected between the twelfth node N12 and the first power supply Vint. In addition, the gate electrode of the fourteenth transistor M14 may be connected to the i-th third scan line S3i. When the third scan signal is supplied to the i-th third scan line S3i, the fourteenth transistor M14 may be turned on to supply the voltage of the first power supply Vint to the twelfth node N12. The first power supply Vint may be set to a voltage lower than the data signal supplied to the m-th data line Dm. The third scan signal supplied to the i-th third scan line S3i may be supplied earlier than the first scan signal supplied to the i-th first scan line S1i. Therefore, the i-th third scan line S3i may be set to the (i - 1)-th first scan line S1i-1.

[0178] The fifteenth transistor M15 may be connected between the anode electrode of the organic light-emitting diode OLED and the first power supply Vint. In addition, the gate electrode of the fifteenth transistor M15 may be connected to the i-th fourth scan line S4i. When the fourth scan signal is supplied to the i-th fourth scan line S4i, the fifteenth transistor M15 may be turned on to supply the voltage of the first power supply Vint to the anode electrode of the organic light-emitting diode OLED. The fourth scan signal supplied to the i-th fourth scan line S4i may overlap with the light emission control signal supplied to the i-th light emission control line Ei. Therefore, the i-th fourth scan line S4i may be set to the i-th first scan line S1i or the i-th third scan line S3i.

[0179] When the voltage of the first power supply Vint is supplied to the anode electrode of the organic light-emitting diode OLED, the parasitic capacitor of the organic light-emitting diode OLED (hereinafter, referred to as "organic capacitor Coled") may be discharged. When the organic capacitor Coled is discharged, the black display ability of the pixel PXL may be enhanced.

[0180] More specifically, the organic capacitor Coled may be charged with a predetermined voltage corresponding to the current supplied from the pixel circuit 2003 during the previous frame period. When the organic capacitor Coled is charged, the organic light-emitting diode OLED may easily emit light at a lower current.

[0181] A black data signal may be supplied to the pixel circuit 2003 during a current frame period. When the black data signal is supplied, the pixel circuit 2003 undesirably supplies current to the organic light-emitting diode OLED. However, even when the black data signal is supplied, the pixel circuit 2003 formed of transistors supplies a predetermined leakage current to the organic light-emitting diode OLED. When the organic capacitor Coled is charged, the organic light-emitting diode OLED emits light weakly, thereby degrading the black display ability.

[0182] On the contrary, as in the present disclosure, when the organic capacitor Coled is discharged by the first power supply Vint, the organic light-emitting diode OLED can be set to a non-emitting state even when a leakage current is supplied. That is, according to the present disclosure, the black display ability can be improved by discharging the organic capacitor Coled using the first power supply Vint.

[0183] The sixteenth transistor M16 may be connected between the first driving power supply ELVDD and the eleventh node N11. In addition, the gate electrode of the sixteenth transistor M16 may be connected to the i-th light emission control line Ei. When a light emission control signal is supplied to the i-th light emission control line Ei, the sixteenth transistor M16 may be turned off, and when the light emission control signal is not supplied, the sixteenth transistor M16 may be turned on.

[0184] The seventeenth transistor M17 may be connected between the eleventh transistor M11 and the anode electrode of the organic light-emitting diode OLED. In addition, the gate electrode of the seventeenth transistor M17 may be connected to the i-th light emission control line Ei. When a light emission control signal is supplied to the i-th light emission control line Ei, the seventeenth transistor M17 may be turned off, and when the light emission control signal is not supplied, the seventeenth transistor M17 may be turned on.

[0185] The storage capacitor Cst may be connected between the first driving power supply ELVDD and the twelfth node N12. The storage capacitor Cst may be charged with a voltage corresponding to the data signal and a voltage corresponding to the threshold voltage of the eleventh transistor M11.

[0186] In the above pixel PXL of the present disclosure, the eleventh transistor M11 to the seventeenth transistor M17 may be formed of P-type polysilicon semiconductor transistors. Specifically, the eleventh transistor M11, the sixteenth transistor M16, and the seventeenth transistor M17 provided on the current supply path for supplying current to the organic light-emitting diode OLED may be formed of P-type polysilicon semiconductor transistors. When the eleventh transistor M11 to the seventeenth transistor M17 are formed of polysilicon semiconductor transistors, fast driving characteristics can be ensured.

[0187] In addition, the auxiliary transistor MS11 can be formed of an N-type oxide semiconductor transistor. When the auxiliary transistor MS11 is formed of an oxide semiconductor transistor, the leakage current from the twelfth node N12 can be minimized, and thus an image with a predetermined luminance can be displayed in the pixel region 100.

[0188] Figure 13 is a waveform diagram showing Figure 12 an embodiment of a driving method of the pixel shown in. In Figure 13 it, it is assumed that the i-th third scan line S3i is set as the (i - 1)-th first scan line S1i - 1, and the i-th fourth scan line S4i is set as the i-th first scan line S1i.

[0189] Referring to Figure 13 , a light emission control signal can be supplied to the i-th light emission control line Ei. When the light emission control signal is supplied to the i-th light emission control line Ei, the sixteenth transistor M16 and the seventeenth transistor M17 can be turned off.

[0190] When the sixteenth transistor M16 is turned off, the first driving power supply ELVDD and the eleventh node N11 can be electrically disconnected. When the seventeenth transistor M17 is turned off, the eleventh transistor M11 and the organic light emitting diode OLED can be electrically disconnected. Therefore, when the light emission control signal is supplied to the i-th light emission control line Ei, the pixel PXL can be set to a non-emission state.

[0191] After the light emission control signal is supplied to the i-th light emission control line Ei, a third scan signal can be supplied to the i-th third scan line S3i (i.e., the (i - 1)-th first scan line S1i - 1). When the third scan signal is supplied to the i-th third scan line S3i, the fourteenth transistor M14 can be turned on. When the fourteenth transistor M14 is turned on, the voltage of the first power supply Vint can be supplied to the twelfth node N12. The twelfth node N12 can be initialized to the voltage of the first power supply Vint.

[0192] After the twelfth node N12 is initialized to the voltage of the first power supply Vint, a first scan signal can be supplied to the i-th first scan line Sli, a second scan signal can be supplied to the i-th second scan line S2i, and a fourth scan signal can be supplied to the i-th fourth scan line S4i. The i-th fourth scan line S4i can be set as the i-th first scan line Sli.

[0193] When a fourth scan signal is supplied to the i-th fourth scan line S4i, the fifteenth transistor M15 may be turned on. When the fifteenth transistor M15 is turned on, the voltage of the first power supply Vint may be supplied to the anode electrode of the organic light-emitting diode OLED. When the voltage of the first power supply Vint is supplied to the anode electrode of the organic light-emitting diode OLED, the organic capacitor Coled may be discharged, thereby improving the black display ability.

[0194] When a second scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS11 may be turned on. When the auxiliary transistor MS11 is turned on, the second electrode of the eleventh transistor M11 and the thirteenth transistor M13 may be electrically connected.

[0195] When a first scan signal is supplied to the i-th first scan line Sli, the twelfth transistor M12 and the thirteenth transistor M13 may be turned on.

[0196] When the thirteenth transistor M13 is turned on, the auxiliary transistor MS11 and the twelfth node N12 may be electrically connected. Since the auxiliary transistor MS11 is set to the on state, the twelfth node N12 and the second electrode of the eleventh transistor M11 may be electrically connected to each other, so that the eleventh transistor M11 may be connected in a diode form.

[0197] When the twelfth transistor M12 is turned on, the data signal from the m-th data line Dm may be supplied to the eleventh node N11. Since the twelfth node N12 is initialized to the voltage of the first power supply Vint lower than the data signal, the eleventh transistor M11 may be turned on.

[0198] When the eleventh transistor M11 is turned on, the data signal supplied to the eleventh node N11 may be supplied to the twelfth node N12 via the auxiliary transistor MS11 and the eleventh transistor M11 connected in a diode form. The voltage corresponding to the data signal and the threshold voltage of the eleventh transistor M11 may be applied to the twelfth node N12. The voltage corresponding to the data signal and the threshold voltage of the eleventh transistor M11 may be stored in the storage capacitor Cst.

[0199] After a predetermined voltage is charged into the storage capacitor Cst, the supply of the first scan signal to the i-th first scan line Sli may be stopped, so that the thirteenth transistor M13 and the fifteenth transistor M15 may be turned off.

[0200] After the thirteenth transistor M13 is turned off, the supply of the second scan signal to the i-th second scan line S2i can be stopped. When the supply of the second scan signal to the i-th second scan line S2i is stopped, the auxiliary transistor MS11 can be turned off. Since the thirteenth transistor M13 is set to the off state, the voltage of the twelfth node N12 can be prevented from being changed by the channel capacitor of the auxiliary transistor MS11 formed of an oxide semiconductor transistor.

[0201] Thereafter, the supply of the light emission control signal to the i-th light emission control line Ei can be stopped. When the supply of the light emission control signal to the i-th light emission control line Ei is stopped, the sixteenth transistor M16 and the seventeenth transistor M17 can be turned on.

[0202] When the sixteenth transistor M16 is turned on, the first driving power supply ELVDD and the eleventh node N11 can be electrically connected. When the seventeenth transistor M17 is turned on, the second electrode of the eleventh transistor M11 can be electrically connected to the anode of the organic light emitting diode OLED. The eleventh transistor M11 can control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light emitting diode OLED in response to the voltage applied to the twelfth node N12.

[0203] As described above, the pixel PXL according to another embodiment of the present disclosure can generate light of a predetermined luminance by repeating the above-described period. In addition, since the auxiliary transistor MS11 formed of an oxide semiconductor transistor is turned off during the period when the organic light emitting diode OLED emits light, the leakage current from the twelfth node N12 can be minimized, so that the pixel PXL can generate light of a desired luminance.

[0204] Figure 14 is a view showing a pixel PXL according to another embodiment of the present disclosure. In Figure 14 the description of, the same reference numerals will be given to the components that are the same as those in Figure 12 and the detailed description thereof will be omitted.

[0205] Referring to Figure 14 , the pixel PXL according to another embodiment of the present disclosure can include an organic light emitting diode OLED and a pixel circuit 2003' that controls the amount of current supplied to the organic light emitting diode OLED.

[0206] The anode of the organic light emitting diode OLED can be connected to the pixel circuit 2003', and the cathode of the organic light emitting diode OLED can be connected to the second driving power supply ELVSS. The organic light emitting diode OLED can generate light of a predetermined luminance corresponding to the amount of current supplied from the pixel circuit 2003'.

[0207] The pixel circuit 2003' can control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light-emitting diode OLED in response to a data signal. The pixel circuit 2003' can include an eleventh transistor M11, a twelfth transistor M12, a thirteenth transistor M13, a fourteenth transistor M14', a fifteenth transistor M15', a sixteenth transistor M16, a seventeenth transistor M17, an auxiliary transistor MS11, and a storage capacitor Cst.

[0208] The fourteenth transistor M14' can be connected between the twelfth node N12 and the first power supply Vint. In addition, the gate electrode of the fourteenth transistor M14' can be connected to the i-th third scan line S3i. When the third scan signal is supplied to the i-th third scan line S3i, the fourteenth transistor M14' can be turned on to supply the voltage of the first power supply Vint to the twelfth node N12.

[0209] The fourteenth transistor M14' can be formed of an N-type oxide semiconductor transistor. When the fourteenth transistor M14' is formed of an N-type oxide semiconductor transistor, the leakage current flowing from the twelfth node N12 to the first power supply Vint can be minimized, so that the pixel PXL can achieve a desired brightness. In addition, since the fourteenth transistor M14' is formed of an N-type transistor, the i-th third scan line S3i can be set as the (i - 1)-th second scan line S2i-1.

[0210] The fifteenth transistor M15' can be connected between the anode of the organic light-emitting diode OLED and the first power supply Vint. In addition, the gate electrode of the fifteenth transistor M15' can be connected to the i-th fourth scan line S4i. When the fourth scan signal is supplied to the i-th fourth scan line S4i, the fifteenth transistor M15' can be turned on to supply the voltage of the first power supply Vint to the anode of the organic light-emitting diode OLED.

[0211] The fifteenth transistor M15' can be formed of an N-type oxide semiconductor transistor. When the fifteenth transistor M15' is formed of an N-type oxide semiconductor transistor, the leakage current between the anode of the organic light-emitting diode OLED and the first power supply Vint can be minimized, so that the desired brightness can be achieved through the pixel PXL. In addition, since the fifteenth transistor M15' is composed of an N-type transistor, the i-th fourth scan line S4i can be set as the i-th second scan line S2i.

[0212] Figure 15 is a waveform diagram showing Figure 14 an embodiment of the driving method of the pixel shown in. In Figure 15Among them, it is assumed that the i-th third scan line S3i is set as the (i - 1)-th second scan line S2i-1, and the i-th fourth scan line S4i can be set as the i-th second scan line S2i.

[0213] Referring to Figure 15 , a light emission control signal can be supplied to the i-th light emission control line Ei. When the light emission control signal is supplied to the i-th light emission control line Ei, the sixteenth transistor M16 and the seventeenth transistor M17 can be turned off, so the pixel PXL can become a non-emission state.

[0214] After the light emission control signal is supplied to the i-th light emission control line Ei, a third scan signal can be supplied to the i-th third scan line S3i (i.e., the (i - 1)-th second scan line S2i-1). When the third scan signal is supplied to the i-th third scan line S3i, the fourteenth transistor M14' can be turned on. When the fourteenth transistor M14' is turned on, the voltage of the first power supply Vint can be supplied to the twelfth node N12. The twelfth node N12 can be initialized to the voltage of the first power supply Vint.

[0215] After the twelfth node N12 is initialized to the voltage of the first power supply Vint, a first scan signal can be supplied to the i-th first scan line S1i, a second scan signal can be supplied to the i-th second scan line S2i, and a fourth scan signal can be supplied to the i-th fourth scan line S4i. The i-th fourth scan line S4i can be set as the i-th second scan line S2i.

[0216] When the fourth scan signal is supplied to the i-th fourth scan line S4i, the fifteenth transistor M15' can be turned on. When the fifteenth transistor M15' is turned on, the voltage of the first power supply Vint can be supplied to the anode of the organic light-emitting diode OLED. When the voltage of the first power supply Vint is supplied to the anode of the organic light-emitting diode OLED, the organic capacitor Coled can be discharged, thereby improving the black display ability.

[0217] When the second scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS11 can be turned on. When the auxiliary transistor MS11 is turned on, the second electrode of the eleventh transistor M11 and the thirteenth transistor M13 can be electrically connected.

[0218] When the first scan signal is supplied to the i-th first scan line S1i, the twelfth transistor M12 and the thirteenth transistor M13 can be turned on.

[0219] When the thirteenth transistor M13 is turned on, the auxiliary transistor MS11 and the twelfth node N12 can be electrically connected. Since the auxiliary transistor MS11 is set to the on state, the twelfth node N12 and the second electrode of the eleventh transistor M11 can be electrically connected to each other, so that the eleventh transistor M11 can be connected in diode form.

[0220] When the twelfth transistor M12 is turned on, the data signal from the m-th data line Dm can be supplied to the eleventh node N11. Since the twelfth node N12 is initialized to a voltage lower than the first power supply Vint of the data signal, the eleventh transistor M11 can be turned on.

[0221] When the eleventh transistor M11 is turned on, the data signal supplied to the eleventh node N11 can be supplied to the twelfth node N12 via the auxiliary transistor MS11 and the eleventh transistor M11 connected in diode form. The voltage corresponding to the data signal and the threshold voltage of the eleventh transistor M11 can be applied to the twelfth node N12. The voltage corresponding to the data signal and the threshold voltage of the eleventh transistor M11 can be stored in the storage capacitor Cst.

[0222] After a predetermined voltage is charged into the storage capacitor Cst, the supply of the first scan signal to the i-th first scan line S1i can be stopped, so that the thirteenth transistor M13 can be turned off.

[0223] After the thirteenth transistor M13 is turned off, the supply of the second scan signal to the i-th second scan line S2i can be stopped. When the supply of the second scan signal to the i-th second scan line S2i is stopped, the auxiliary transistor MS11 can be turned off. Since the thirteenth transistor M13 is set to the off state, the voltage of the twelfth node N12 can be prevented from being changed by the channel capacitor of the auxiliary transistor MS11 formed by the oxide semiconductor transistor.

[0224] After that, the supply of the light emission control signal to the i-th light emission control line Ei can be stopped. When the supply of the light emission control signal to the i-th light emission control line Ei is stopped, the sixteenth transistor M16 and the seventeenth transistor M17 can be turned on.

[0225] When the sixteenth transistor M16 is turned on, the first driving power supply ELVDD and the eleventh node N11 can be electrically connected. When the seventeenth transistor M17 is turned on, the second electrode of the eleventh transistor M11 can be electrically connected to the anode of the organic light emitting diode OLED. The eleventh transistor M11 can control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light emitting diode OLED in response to the voltage applied to the twelfth node N12.

[0226] As described above, the pixel PXL according to another embodiment of the present disclosure can generate light of a predetermined brightness by repeating the above-described period. Since the fourteenth transistor M14' and the auxiliary transistor MS11 connected to the twelfth node N12 are formed of oxide semiconductor transistors, the leakage current from the twelfth node N12 can be minimized. In addition, since the fifteenth transistor M15' connected between the first power supply Vint and the anode electrode of the organic light emitting diode OLED is formed of an oxide semiconductor transistor, the leakage current between the organic light emitting diode OLED and the first power supply Vint can be minimized.

[0227] Figure 16 is a view showing a pixel PXL according to another embodiment of the present disclosure. For ease of explanation, Figure 16 shows the pixel PXL disposed on the i-th horizontal line and connected to the m-th data line Dm.

[0228] Referring to Figure 16 , the pixel PXL according to another embodiment of the present disclosure may include a pixel circuit 2004 and an organic light emitting diode OLED.

[0229] The anode electrode of the organic light emitting diode OLED may be connected to the pixel circuit 2004, and the cathode electrode of the organic light emitting diode OLED may be connected to the second driving power supply ELVSS. The organic light emitting diode OLED can generate light of a predetermined brightness corresponding to the amount of current supplied from the pixel circuit 2004.

[0230] The pixel circuit 2004 may include a twenty-first transistor M21, a twenty-second transistor M22, a twenty-third transistor M23, a twenty-fourth transistor M24, a twenty-fifth transistor M25, an auxiliary transistor MS21, and a storage capacitor Cst'.

[0231] The first electrode of the twenty-first transistor M21 may be connected to the second electrode of the twenty-fourth transistor M24, and the second electrode of the twenty-first transistor M21 may be connected to the twenty-second node N22 to which the anode electrode of the organic light emitting diode OLED is connected. In addition, the gate electrode of the twenty-first transistor M21 may be connected to the twenty-first node N21. The twenty-first transistor M21 can control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light emitting diode OLED in response to the voltage of the twenty-first node N21. To ensure a fast driving speed, the twenty-first transistor M21 may be formed of an N-type polycrystalline silicon semiconductor transistor.

[0232] The twenty-second transistor M22 may be connected between the auxiliary transistor MS21 and the twenty-first node N21. In addition, the gate electrode of the twenty-second transistor M22 may be connected to the i-th first scan line S1i. When a first scan signal is supplied to the i-th first scan line S1i, the twenty-second transistor M22 may be turned on. When the twenty-second transistor M22 is turned on, the auxiliary transistor MS21 and the twenty-first node N21 may be electrically connected. The twenty-second transistor M22 may be formed of an N-type polysilicon semiconductor transistor to ensure a fast driving speed.

[0233] The auxiliary transistor MS21 may be connected between the m-th data line Dm and the twenty-second transistor M22. In addition, the gate electrode of the auxiliary transistor MS21 may be connected to the i-th second scan line S2i. When a scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS21 may be turned on to electrically connect the m-th data line Dm and the twenty-second transistor M22. The auxiliary transistor MS21 may be formed of an oxide semiconductor transistor. When the auxiliary transistor MS21 is formed of an oxide semiconductor transistor, the voltage of the twenty-first node N21 may be prevented from changing due to a leakage current, thereby displaying an image with a desired luminance.

[0234] The twenty-third transistor M23 may be connected between the twenty-second node N22 and the first power supply Vint. In addition, the gate electrode of the twenty-third transistor M23 may be connected to the i-th third scan line S3i. When a third scan signal is supplied to the i-th third scan line S3i, the twenty-third transistor M23 may be turned on. When the twenty-third transistor M23 is turned on, the voltage of the first power supply Vint may be supplied to the twenty-second node N22. To ensure a fast driving speed, the twenty-third transistor M23 may be formed of an N-type polysilicon semiconductor transistor.

[0235] The twenty-fourth transistor M24 may be connected between the first driving power supply ELVDD and the first electrode of the twenty-first transistor M21. In addition, the gate electrode of the twenty-fourth transistor M24 may be connected to the i-th light emission control line Ei. When a light emission control signal is supplied to the i-th light emission control line Ei, the twenty-fourth transistor M24 may be turned off, and when the light emission control signal is not supplied, the twenty-fourth transistor M24 may be turned on. To ensure a fast driving speed, the twenty-fourth transistor M24 may be formed of an N-type polysilicon semiconductor transistor.

[0236] The twenty-fifth transistor M25 may be connected between a reference power supply Vref and the twenty-first node N21. In addition, a gate electrode of the twenty-fifth transistor M25 may be connected to the i-th fourth scan line S4i. When a fourth scan signal is supplied to the i-th fourth scan line S4i, the twenty-fifth transistor M25 may be turned on, and a voltage of the reference power supply Vref may be supplied to the twenty-first node N21. The twenty-fifth transistor M25 may be formed of an N-type oxide semiconductor transistor. When the twenty-fifth transistor M25 is formed of an N-type oxide semiconductor transistor, a leakage current between the reference power supply Vref and the twenty-first node N21 may be minimized.

[0237] In addition, the reference power supply Vref may be set to a voltage at which the twenty-first transistor M21 is turned on. For example, a voltage (Vref-Vint) obtained by subtracting a voltage of the first power supply Vint from a voltage of the reference power supply Vref may be set to a voltage higher than a threshold voltage of the twenty-first transistor M21.

[0238] A storage capacitor Cst' may be connected between the twenty-first node N21 and the twenty-second node N22. The storage capacitor Cst' may store a voltage corresponding to a data signal and a threshold voltage of the twenty-first transistor M21.

[0239] In the above-described embodiment of the present disclosure, the auxiliary transistor MS21 and the twenty-fifth transistor M25 may be formed of oxide semiconductor transistors. A leakage current from the twenty-first transistor M21 may be minimized, and thus an image of a desired luminance may be displayed.

[0240] In addition, according to an embodiment of the present disclosure, the twenty-fourth transistor M24 and the twenty-first transistor M21 provided on a current supply path for supplying current to the organic light-emitting diode OLED may be formed of polysilicon semiconductor transistors. When the twenty-fourth transistor M24 and the twenty-first transistor M21 provided on the current supply path are formed of polysilicon semiconductor transistors, current may be stably supplied to the organic light-emitting diode OLED due to fast driving characteristics.

[0241] Figure 17 is a waveform diagram showing Figure 16 an embodiment of a driving method of the pixel PXL shown in

[0242] Referring to Figure 17 , a light emission control signal may be supplied to the i-th light emission control line Ei such that the twenty-fourth transistor M24 may be turned off. When the twenty-fourth transistor M24 is turned off, the first driving power supply ELVDD and the twenty-first transistor M21 may be electrically disconnected, so that the pixel PXL may be set to a non-emission state.

[0243] During a first period T1, a third scan signal may be supplied to the i-th third scan line S3i, and a fourth scan signal S4i may be supplied to the i-th fourth scan line S4i.

[0244] When the third scan signal is supplied to the i-th third scan line S3i, the twenty-third transistor M23 may be turned on. When the twenty-third transistor M23 is turned on, the voltage of the first power supply Vint may be supplied to the twenty-second node N22. The organic capacitor Coled may be discharged.

[0245] When the fourth scan signal is supplied to the i-th fourth scan line S4i, the twenty-fifth transistor M25 may be turned on. When the twenty-fifth transistor M25 is turned on, the voltage of the reference power supply Vref may be supplied to the twenty-first node N21.

[0246] During a second period T2, the supply of the third scan signal may be stopped so that the twenty-third transistor M23 may be turned off. In addition, the supply of the emission control signal to the i-th emission control line Ei may be stopped during a part of the second period T2.

[0247] When the supply of the emission control signal to the i-th emission control line Ei is stopped, the twenty-fourth transistor M24 may be turned on. When the twenty-fourth transistor M24 is turned on, the voltage of the first driving power supply ELVDD may be supplied to the first electrode of the twenty-first transistor M21. When the voltage of the first driving power supply ELVDD is supplied to the first electrode of the twenty-first transistor M21, since the twenty-first transistor M21 is turned on, a current flows through the twenty-first transistor M21, and thus the voltage of the twenty-second node N22 increases.

[0248] Since the twenty-first node N21 maintains the voltage of the reference power supply Vref, the twenty-second node N22 may increase to a voltage obtained by subtracting the threshold voltage of the twenty-first transistor M21 from the reference power supply Vref. Therefore, the threshold voltage of the twenty-first transistor M21 may be stored in the storage capacitor Cst'.

[0249] After the second period T2, the supply of the fourth scan signal to the i-th fourth scan line S4i may be stopped. When the supply of the fourth scan signal to the i-th fourth scan line S4i is stopped, the twenty-fifth transistor M25 may be turned off.

[0250] In the third period T3, the first scan signal can be supplied to the i-th first scan line S1i, and the second scan signal can be supplied to the i-th second scan line S2i. When the first scan signal is supplied to the i-th first scan line S1i, the twenty-second transistor M22 can be turned on. When the second scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS21 can be turned on. When the twenty-second transistor M22 and the auxiliary transistor MS21 are turned on, the m-th data line Dm and the twenty-first node N21 can be electrically connected. The data signal DS from the m-th data line Dm can be supplied to the twenty-first node N21.

[0251] The data signal DS supplied to the twenty-first node N21 can be stored in the storage capacitor Cst'. That is, during the second period T2 and the third period T3, the voltage corresponding to the data signal DS and the threshold voltage of the twenty-first transistor M21 can be stored in the storage capacitor Cst'.

[0252] In the fourth period T4, the light emission control signal can be stopped from being supplied to the i-th light emission control line Ei. When the light emission control signal is stopped from being supplied to the i-th light emission control line Ei, the twenty-fourth transistor M24 can be turned on.

[0253] When the twenty-fourth transistor M24 is turned on, the first driving power supply ELVDD and the twenty-first transistor M21 can be electrically connected. The twenty-first transistor M21 can be turned on and a predetermined current can flow into the twenty-second node N22. The current flowing out of the twenty-first transistor M21 can be stored in the capacitor (C = Cst'+Coled) which is a coupling capacitor of the storage capacitor Cst' and the organic capacitor Coled, so the voltage of the twenty-second node N22 can increase. The increase in the voltage of the twenty-second node N22 can be set differently for each pixel PXL corresponding to the mobility of the twenty-first transistor M21, so the mobility of the twenty-first transistor M21 can be compensated. The time assigned to the fourth period T4 can be experimentally determined so that the mobility of the twenty-first transistor M21 can be compensated.

[0254] After the fourth period T4, the first scan signal can be stopped from being supplied to the i-th first scan line S1i, so the twenty-second transistor M22 can be turned off. After the twenty-second transistor M22 is turned off, the second scan signal can be stopped from being supplied to the i-th second scan line S2i, so the auxiliary transistor MS21 can be turned off. Since the twenty-second transistor M22 is set to the off state, the voltage of the twenty-first node N21 can be prevented from being changed by the channel capacitor of the auxiliary transistor MS21 formed of an oxide semiconductor transistor.

[0255] In the fifth period T5, the twenty-first transistor M21 may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light-emitting diode OLED in response to the voltage of the twenty-first node N21. The organic light-emitting diode OLED may generate light of a predetermined brightness corresponding to the amount of current.

[0256] Figure 18 is a view showing a pixel according to another embodiment of the present disclosure. For ease of explanation, Figure 18 shows a pixel PXL provided on the i-th horizontal line and connected to the m-th data line Dm.

[0257] Referring to Figure 18 , the pixel PXL according to an embodiment of the present disclosure may include an organic light-emitting diode OLED and a pixel circuit 2005.

[0258] The anode electrode of the organic light-emitting diode OLED may be connected to the pixel circuit 2005, and the cathode electrode of the organic light-emitting diode OLED may be connected to the second driving power supply ELVSS. The organic light-emitting diode OLED may generate light of a predetermined brightness corresponding to the amount of current supplied from the pixel circuit 2005.

[0259] The pixel circuit 2005 may control the amount of current flowing from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light-emitting diode OLED in response to a data signal. The pixel circuit 2005 may include a thirty-first transistor M31, a thirty-second transistor M32, a thirty-third transistor M33, a thirty-fourth transistor M34, a thirty-fifth transistor M35, a thirty-sixth transistor M36, an auxiliary transistor MS31, and a storage capacitor Cst.

[0260] The first electrode of the thirty-first transistor M31 may be connected to the first driving power supply ELVDD, and the second electrode of the thirty-first transistor M31 may be connected to the anode electrode of the organic light-emitting diode OLED via the thirty-sixth transistor M36. In addition, the gate electrode of the thirty-first transistor M31 may be connected to the thirty-first node N31. The thirty-first transistor M31 may control the amount of current supplied from the first driving power supply ELVDD to the second driving power supply ELVSS via the organic light-emitting diode OLED in response to the voltage of the thirty-first node N31. To ensure a fast driving speed, the thirty-first transistor M31 may be formed of a P-type polysilicon semiconductor transistor.

[0261] The thirty-second transistor M32 may be connected between the thirty-first node N31 and the second electrode of the thirty-first transistor M31. In addition, the gate electrode of the thirty-second transistor M32 may be connected to the i-th first scan line S1i. When a first scan signal is supplied to the i-th first scan line S1i, the thirty-second transistor M32 may be turned on. When the thirty-second transistor M32 is turned on, the thirty-first transistor M31 may be connected in a diode form. The thirty-second transistor M32 may be formed of a p-type polysilicon semiconductor transistor to ensure a fast driving speed.

[0262] The thirty-third transistor M33 may be connected between the auxiliary transistor MS31 and the thirty-second node N32. In addition, the gate electrode of the thirty-third transistor M33 may be connected to the i-th first scan line S1i. When a first scan signal is supplied to the i-th first scan line S1i, the thirty-third transistor M33 may be turned on. When the thirty-third transistor M33 is turned on, the auxiliary transistor MS31 and the thirty-second node N32 may be electrically connected. The thirty-third transistor M33 may be formed of a p-type polysilicon semiconductor transistor to ensure a fast driving speed.

[0263] The auxiliary transistor MS31 may be connected between the m-th data line Dm and the thirty-third transistor M33. In addition, the gate electrode of the auxiliary transistor MS31 may be connected to the i-th second scan line S2i. When a second scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS31 may be turned on to electrically connect the m-th data line Dm and the thirty-third transistor M33. The auxiliary transistor MS31 may be formed of an oxide semiconductor transistor. When the auxiliary transistor MS31 is formed of an oxide semiconductor transistor, the voltage of the thirty-second node N32 may be prevented from changing due to a leakage current, thereby displaying an image with a desired luminance.

[0264] The thirty-fourth transistor M34 may be connected between the thirty-second node N32 and the first power supply Vint'. In addition, the gate electrode of the thirty-fourth transistor M34 may be connected to the i-th inverted emission control line / Ei. When an inverted emission control signal is supplied to the i-th inverted emission control line / Ei, the thirty-fourth transistor M34 may be turned off, and when the inverted emission control signal is not supplied, the thirty-fourth transistor M34 may be turned on. When the thirty-fourth transistor M34 is turned on, the voltage of the first power supply Vint' may be supplied to the thirty-second node N32. The thirty-fourth transistor M34 may be formed of an oxide semiconductor transistor so that the leakage current from the thirty-second node N32 can be minimized.

[0265] In addition, the inverted light emission control signal supplied to the i-th inverted light emission control line / Ei can be set to a signal obtained by inverting the light emission control signal supplied to the i-th light emission control line Ei. For example, when the light emission control signal is set to a high voltage, the inverted light emission control signal can be set to a low voltage.

[0266] The thirty-fifth transistor M35 can be connected between the anode electrode of the organic light-emitting diode OLED and the first power supply Vint'. In addition, the gate electrode of the thirty-fifth transistor M35 can be connected to the i-th first scan line S1i. When the first scan signal is supplied to the i-th first scan line S1i, the thirty-fifth transistor M35 can be turned on. When the thirty-fifth transistor M35 is turned on, the voltage of the first power supply Vint' can be supplied to the anode electrode of the organic light-emitting diode OLED. The thirty-fifth transistor M35 can be formed of a P-type polysilicon semiconductor transistor.

[0267] The thirty-sixth transistor M36 can be connected between the second electrode of the thirty-first transistor M31 and the anode electrode of the organic light-emitting diode OLED. In addition, the gate electrode of the thirty-sixth transistor M36 can be connected to the i-th light emission control line Ei. When the light emission control signal is supplied to the i-th light emission control line Ei, the thirty-sixth transistor M36 can be turned off, and when the light emission control signal is not supplied, the thirty-sixth transistor M36 can be turned on. The thirty-sixth transistor M36 can be formed of a P-type polysilicon semiconductor transistor.

[0268] The storage capacitor Cst can be connected between the thirty-first node N31 and the thirty-second node N32. The storage capacitor Cst can store the voltage corresponding to the data signal and the threshold voltage of the thirty-first transistor M31.

[0269] According to another embodiment of the present disclosure described above, the auxiliary transistor MS31 and the thirty-fourth transistor M34 can be formed of oxide semiconductor transistors. When the auxiliary transistor MS31 and the thirty-fourth transistor M34 are formed of oxide semiconductor transistors, the voltage change of the thirty-second node N32 caused by leakage current can be minimized, thereby displaying an image with a desired brightness.

[0270] In addition, in another embodiment of the present disclosure described above, the thirty-first transistor M31 and the thirty-sixth transistor M36 provided on the current supply path for supplying current to the organic light-emitting diode OLED can be formed of polysilicon semiconductor transistors. When the thirty-first transistor M31 and the thirty-sixth transistor M36 provided on the current supply path are formed of polysilicon semiconductor transistors, current can be stably supplied to the organic light-emitting diode OLED due to fast driving characteristics.

[0271] Figure 19is a waveform diagram showing an embodiment of a driving method of a pixel PXL shown in Figure 18 the waveform diagram.

[0272] Referring to Figure 19 , a first scan signal may be supplied to the i-th first scan line S1i, and a second scan signal may be supplied to the i-th second scan line S2i.

[0273] When the first scan signal is supplied to the i-th first scan line Sli, the thirty-second transistor M32, the thirty-third transistor M33, and the thirty-fifth transistor M35 may be turned on.

[0274] When the thirty-fifth transistor M35 is turned on, the voltage of the first power supply Vint' may be supplied to the anode electrode of the organic light-emitting diode OLED.

[0275] When the thirty-second transistor M32 is turned on, the thirty-first transistor M31 may be connected in a diode form. The thirty-first node N31 may be electrically connected to the first power supply Vint' via the thirty-sixth transistor M36 and the thirty-fifth transistor M35. The thirty-first node N31 may be initialized to the voltage of the first power supply Vint'.

[0276] When the thirty-third transistor M33 is turned on, the thirty-second node N32 and the auxiliary transistor MS31 may be electrically connected.

[0277] When the second scan signal is supplied to the i-th second scan line S2i, the auxiliary transistor MS31 may be turned on. When the auxiliary transistor MS31 is turned on, the m-th data line Dm and the thirty-second node N32 may be electrically connected.

[0278] A light emission control signal may be supplied to the i-th light emission control line Ei to partially overlap with the first scan signal and the second scan signal, and an inverted light emission control signal may be supplied to the i-th inverted light emission control line / Ei.

[0279] When the light emission control signal is supplied to the i-th light emission control line Ei, the thirty-sixth transistor M36 may be turned off. When the thirty-sixth transistor M36 is turned off, the voltage obtained by subtracting the absolute value of the threshold voltage of the thirty-first transistor M31 from the first driving power supply ELVDD may be applied to the thirty-first node N31 through the thirty-first transistor M31 connected in a diode form.

[0280] When an inverted emission control signal is supplied to the i-th inverted emission control line / Ei, the thirty-fourth transistor M34 can be turned off. When the thirty-fourth transistor is turned off, the electrical connection between the thirty-second node N32 and the first power supply Vint' can be disconnected. Since the auxiliary transistor MS31 and the thirty-third transistor M33 remain in the on state, the voltage of the data signal can be applied to the thirty-second node N32.

[0281] Accordingly, a voltage corresponding to the voltage difference between the thirty-second node N32 and the thirty-first node N31 can be charged in the storage capacitor Cst. That is, the voltage corresponding to the data signal and the threshold voltage of the thirty-first transistor M31 can be stored in the storage capacitor Cst.

[0282] After a predetermined voltage is charged in the storage capacitor Cst, the supply of the first scan signal to the i-th first scan line Sli can be stopped. When the supply of the first scan signal to the i-th first scan line Sli is stopped, the thirty-second transistor M32, the thirty-third transistor M33, and the thirty-fifth transistor M35 can be turned off.

[0283] After the supply of the first scan signal to the i-th first scan line Sli is stopped, the supply of the second scan signal to the i-th second scan line S2i can be stopped. When the supply of the second scan signal to the i-th second scan line S2i is stopped, the auxiliary transistor MS31 can be turned off. Since the thirty-third transistor M33 remains in the off state, the voltage of the thirty-second node N32 can be prevented from being changed by the kick-back voltage of the auxiliary transistor MS31.

[0284] The supply of the emission control signal to the i-th emission control line Ei can be stopped, and the supply of the inverted emission control signal to the i-th inverted emission control line / Ei can be stopped. When the supply of the emission control signal to the i-th emission control line Ei is stopped, the thirty-sixth transistor M36 can be turned on. When the thirty-sixth transistor M36 is turned on, the thirty-first transistor M31 and the organic light-emitting diode OLED can be electrically connected.

[0285] When the supply of the inverted emission control signal to the i-th inverted emission control line / Ei is stopped, the voltage of the first power supply Vint' can be supplied to the thirty-second node N32. The voltage of the first power supply Vint' can be set to a specific voltage within the voltage range of the data signal.

[0286] When a black data signal is applied to the thirty-second node N32, the voltage of the thirty-second node N32 may be maintained constant or increase by a predetermined voltage when the voltage of the first power supply Vint' is supplied. The voltage of the thirty-first node N31 may increase by a predetermined voltage corresponding to the voltage change of the thirty-second node N32, or maintain the voltage of the previous period. For example, the thirty-first node N31 may be maintained at a voltage obtained by subtracting the absolute value of the threshold voltage of the thirty-first transistor M31 from the first driving power supply ELVDD. The thirty-first transistor M31 may remain in the off state.

[0287] When a data signal corresponding to a gray level other than the black gray level is applied to the thirty-second node N32, the voltage of the thirty-second node N32 may decrease by a predetermined voltage when the voltage of the first power supply Vint' is supplied. The voltage of the thirty-first node N31 may decrease by a predetermined voltage corresponding to the voltage change of the thirty-second node N32. When the voltage of the thirty-first node N31 decreases, the thirty-first transistor M31 may be turned on. The thirty-first transistor M31 may supply a current corresponding to the thirty-first node N31 to the organic light-emitting diode OLED.

[0288] The voltage drop of the thirty-second node N32 may be determined by the data signal. That is, the voltage drop of the thirty-first node N31 may be determined by the data signal, and the thirty-first transistor M31 may control the amount of current corresponding to the data signal.

[0289] A pixel according to an embodiment of the present disclosure and an organic light-emitting display device having the pixel may form an oxide semiconductor transistor on a leakage current path to reduce the leakage current, so that a desired image can be displayed. Specifically, according to an embodiment of the present disclosure, a polysilicon semiconductor transistor may be formed to be connected to the oxide semiconductor transistor. The polysilicon semiconductor transistor may be turned off before the oxide semiconductor transistor, so that the voltage of the gate electrode of the driving transistor can be prevented from being changed by the backflow voltage of the oxide semiconductor transistor.

[0290] Although the present disclosure has been specifically shown and described with reference to exemplary embodiments of the present disclosure, it should be understood that the present disclosure is not limited to the disclosed exemplary embodiments. In addition, those skilled in the art will understand that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as set forth in the appended claims.

[0291] The scope of the present disclosure should not be limited to the details described in the detailed description of the specification, but should be defined by the claims. In addition, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present disclosure.

Claims

1. A pixel, the pixel comprising: A light emitting diode; A first transistor, electrically connected to a first driving power source and the light emitting diode; A second transistor, electrically connected to an electrode of the first transistor and the gate electrode of the first transistor; A third transistor, electrically connected to the first transistor and the anode of the light emitting diode; A fourth transistor, electrically connected to the anode of the light emitting diode and a first power source; A capacitor, comprising a first electrode connected to the gate electrode of the first transistor and a second electrode electrically connected to the first power source; A fifth transistor, comprising a first electrode connected to the second electrode of the capacitor, a second electrode connected to the first power source and the fourth transistor, and a gate electrode connected to a first light control line; And A parasitic capacitor, connected in parallel to the light emitting diode, wherein, the gate electrode of the second transistor and the gate electrode of the fourth transistor are connected to a first scan line, wherein, both the second electrode of the capacitor and the parasitic capacitor are electrically connected to the first power source, and wherein, the gate electrode of the third transistor is connected to a second light control line.

2. The pixel according to claim 1, the pixel further comprising: A sixth transistor, electrically connected to a data line and the capacitor.

3. The pixel according to claim 2, wherein, The gate electrode of the sixth transistor is connected to a second scan line.

4. The pixel according to claim 3, wherein The sixth transistor is an N-type transistor.

5. The pixel according to claim 3, wherein The sixth transistor comprises an oxide semiconductor as an active layer.

6. The pixel according to claim 5, the pixel further comprising: A seventh transistor, electrically connected to the sixth transistor and the capacitor.

7. The pixel according to claim 6, wherein, The gate electrode of the seventh transistor is connected to the first scan line.

8. The pixel according to claim 7, wherein, The seventh transistor comprises polysilicon as an active layer.

9. The pixel according to claim 8, wherein, The sixth transistor and the seventh transistor have overlapping conduction periods, and the seventh transistor turns off before the sixth transistor turns off.

Images