KR102097473B1 - Pixel and organic light emitting display device using the same - Google Patents

Abstract

The present invention relates to one pixel to improve display quality.
A pixel according to an embodiment of the present invention includes an organic light emitting diode having a cathode electrode connected to a second power source; A pixel circuit including a driving transistor which is connected to the j (j is a natural number) scan line and a data line and controls the amount of current flowing from the first power supply to the second power supply through the organic light emitting diode; A first transistor connected between a voltage source and an anode electrode of the organic light emitting diode and turned on when a scan signal is supplied to the i (i is a natural number) scan line; And a boosting capacitor connected between the i-th scan line and the anode electrode of the organic light emitting diode.

Description

Pixel and organic light emitting display device using the same {PIXEL AND ORGANIC LIGHT EMITTING DISPLAY DEVICE USING THE SAME}

An embodiment of the present invention relates to a pixel and an organic light emitting display device using the same, and more particularly, to a pixel and an organic light emitting display device using the same to improve display quality.

With the development of information technology, the importance of a display device that is a connection medium between a user and information is highlighted. In response, flat panel displays such as liquid crystal display devices (LCDs), organic light emitting display devices (OLEDs), and plasma display panels (PDPs), etc. The use of FPD) is increasing.

Among the flat panel display devices, the organic light emitting display device displays an image using an organic light emitting diode that generates light by recombination of electrons and holes, which has the advantage of having a fast response speed and driving with low power consumption. .

The organic light emitting display device includes a plurality of pixels arranged in a matrix form at intersections of a plurality of data lines, scan lines, and power lines. The pixels generally include an organic light emitting diode and a driving transistor for controlling the amount of current flowing through the organic light emitting diode. Such pixels generate light of a predetermined luminance while supplying current from the driving transistor to the organic light emitting diode in response to the data signal.

On the other hand, due to the increase in the efficiency and the resolution of the organic light emitting diode, the organic light emitting diode can easily emit light at a low current. In this case, there is an advantage that can display a high luminance image while lowering power consumption.

However, when the organic light emitting diode easily emits light even at a low current, there is a problem in that the luminance of black increases. In other words, when the pixel expresses black, the organic light emitting diode is finely emitted by the leakage current, and accordingly, there is a problem that the contrast ratio is lowered.

Accordingly, a technical object of the present invention is to provide a pixel and an organic light emitting display device using the same so as to improve the display quality.

A pixel according to an embodiment of the present invention includes an organic light emitting diode having a cathode electrode connected to a second power source; A pixel circuit including a driving transistor which is connected to the j (j is a natural number) scan line and a data line and controls the amount of current flowing from the first power supply to the second power supply through the organic light emitting diode; A first transistor connected between a voltage source and an anode electrode of the organic light emitting diode and turned on when a scan signal is supplied to the i (i is a natural number) scan line; And a boosting capacitor connected between the i-th scan line and the anode electrode of the organic light emitting diode.

According to an embodiment, before the scan signal is supplied to the j-th scan line, a voltage of an initialization power lower than the data signal supplied to the data line is supplied to the gate electrode of the driving transistor.

According to an embodiment, the voltage source is set to the second power source or the initializing power source.

According to an embodiment, the voltage source is set to a voltage lower than the data signal supplied to the data line.

According to an embodiment, the i-th scan line is set to a j-1 scan line.

According to an embodiment, the pixel circuit may include a driving transistor for controlling the amount of current supplied from the first power source connected to the organic light emitting diode via the first node in response to the voltage of the second node; A fifth transistor positioned between the data line and the first node and turned on when a scan signal is supplied to the j-th scan line; A third transistor connected between the second node and the initialization power supply and turned on when a scan signal is supplied to the j-1 scan line; A fourth transistor is connected between the second node and the second electrode of the driving transistor, and is turned on when a scan signal is supplied to the j-th scan line.

According to an embodiment, the pixel circuit is connected between the first node and the first power source, and is turned off when a light emission control signal is supplied to the jth emission control line, and is turned on in other cases. 6 transistors; The seventh transistor is connected between the anode electrode of the organic light emitting diode and the second electrode of the driving transistor, and is turned off when a light emission control signal is supplied to the j emission control line and turned on in other cases. Have more.

An organic light emitting display device according to an exemplary embodiment of the present invention includes a scan driver for supplying a scan signal to scan lines and a light emission control signal to light emission control lines; A data driver for supplying data signals to data lines; Pixels located in an area partitioned by the scan lines and the data lines; Each of the pixels positioned on the jth (j is a natural number) horizontal line includes an organic light emitting diode having a cathode electrode connected to a second power source; A pixel circuit connected to the j-th scan line and the data line, the pixel circuit including a driving transistor controlling an amount of current flowing from the first power supply to the second power supply through the organic light emitting diode; A first transistor connected between a voltage source set at a voltage lower than the data signal and the anode electrode of the organic light emitting diode, and turned on when a scan signal is supplied to the i (i is a natural number) scan line; And a boosting capacitor connected between the i-th scan line and the anode electrode of the organic light emitting diode.

According to an embodiment, a voltage of an initialization power lower than the data signal is supplied to the gate electrode of the driving transistor before the scan signal is supplied to the j-th scan line.

According to an embodiment, the voltage source is set to the second power source or the initializing power source.

According to an embodiment, the i-th scan line is set to a j-1 scan line.

According to an embodiment, the scan driver supplies a light emission control signal to the j emission control line so as to partially overlap the scan signal supplied to the j-1 scan line and completely overlap with the scan signal supplied to the j scan line.

According to an embodiment, the pixel circuit may include a driving transistor for controlling the amount of current supplied from the first power source connected to the organic light emitting diode via the first node in response to the voltage of the second node; A fifth transistor positioned between the data line and the first node and turned on when a scan signal is supplied to the j-th scan line; A third transistor connected between the second node and an initialization power source and turned on when a scan signal is supplied to the j-1 scan line; A fourth transistor is connected between the second node and the second electrode of the driving transistor, and is turned on when a scan signal is supplied to the j-th scan line.

According to an embodiment, the pixel circuit is connected between the first node and the first power supply, and is turned off when a light emission control signal is supplied to the j emission control line, and is turned on in other cases. A sixth transistor; The seventh transistor is connected between the anode electrode of the organic light emitting diode and the second electrode of the driving transistor, and is turned off when a light emission control signal is supplied to the j emission control line and turned on in other cases. Have more.

According to the pixel and the organic light emitting display device using the same according to an embodiment of the present invention, the anode electrode of the organic light emitting diode is initialized to a low voltage, and the anode electrode voltage of the organic light emitting diode is turned using the boosting capacitor. -Raise below the on-voltage. In this case, it is possible to prevent the organic light emitting diode from emitting light due to the leakage current and to improve the low gradation expression ability. For example, a transistor positioned between the anode electrode of the organic light emitting diode and the voltage source provides a leakage path, and it is possible to prevent the organic light emitting diode from emitting light due to a leakage current supplied when black is expressed by the leakage path. In addition, when the anode electrode voltage of the organic light emitting diode is increased by using the boosting capacitor, the voltage change of the gate electrode of the driving transistor due to the voltage change of the second power source can be minimized.

1 is a view showing an organic light emitting display device according to an embodiment of the present invention.
2 is a view showing a pixel according to an embodiment of the present invention.
3 is a diagram illustrating an embodiment of the pixel circuit shown in FIG. 2.
4 is a waveform diagram illustrating a method of driving a pixel illustrated in FIG. 3.
5 is a graph showing a voltage change of the gate electrode of the driving transistor corresponding to the voltage change of the second power source.

Hereinafter, with reference to Figures 1 to 5 attached to a preferred embodiment that can be easily carried out by the person of ordinary skill in the art to which the present invention pertains to the present invention will be described.

1 is a view showing an organic light emitting display device according to an embodiment of the present invention.

Referring to FIG. 1, an organic light emitting display device according to an exemplary embodiment of the present invention includes pixels 140 positioned in an area partitioned by scan lines S1 to Sn and data lines D1 to Dm. The pixel unit 130, the scan driving units 110 for driving the scan lines S1 to Sn and the emission control lines E1 to En, and the data driving unit 120 for driving the data lines D1 to Dm And a timing control unit 150 for controlling the scan driving unit 110 and the data driving unit 120.

The timing control unit 150 generates a data driving control signal DCS and a scanning driving control signal SCS in response to synchronization signals (not shown) supplied from the outside. The data driving control signal DCS generated by the timing controller 150 is supplied to the data driving unit 120, and the scanning driving control signal SCS is supplied to the scanning driving unit 110. In addition, the timing controller 150 supplies the data Data supplied from the outside to the data driver 120.

The scan driver 110 receives the scan drive control signal SCS from the timing controller 150. The scan driver 110 receiving the scan driving control signal SCS generates a scan signal and supplies the generated scan signal to the scan lines S1 to Sn. Further, the scan driver 110 generates a light emission control signal in response to the scan driving control signal SCS, and supplies the generated light emission control signal to the light emission control lines E1 to En. Here, the width of the emission control signal is set equal to or wider than the width of the scan signal. For example, the emission control signal supplied to the k (k is a natural number) th emission control line Ek may be supplied overlapping the scanning signals supplied to the k-1 th and k th scan lines Sk-1 and Sk. have.

The data driver 120 receives a data drive control signal DCS from the timing controller 150. The data driver 120 receiving the data driving control signal DCS generates a data signal and supplies the generated data signal to the data lines D1 to Dm to be synchronized with the scanning signal.

The pixel unit 130 includes pixels 140 positioned in an area partitioned by scan lines S1 to Sn and data lines D1 to Dm. The pixels 140 are supplied with a second power supply ELVSS set to a lower voltage than the first power supply ELVDD and the first power supply ELVDD from the outside.

Each of the pixels 140 includes a driving transistor (not shown) and an organic light emitting diode. The driving transistor controls the amount of current flowing from the first power supply ELVDD to the second power supply ELVSS via the organic light emitting diode. Meanwhile, in the present invention, the driving transistor is connected in the form of a diode during a period in which the data signal is supplied so that the threshold voltage of the driving transistor can be compensated. To this end, the gate electrode of the driving transistor included in each of the pixels 140 is initialized by a voltage of an initialization power not shown before the data signal is supplied.

2 is a view showing a pixel according to an embodiment of the present invention. In FIG. 2, for convenience of description, a pixel 140 connected to the mth data line Dm and positioned at a j (j is a natural number) horizontal line is illustrated.

Referring to FIG. 2, the pixel 140 according to an embodiment of the present invention includes an organic light emitting diode (OLED), a pixel circuit 142 for controlling the amount of current supplied to the organic light emitting diode (OLED), and an organic light emitting diode Boosting connected between the anode electrode of (OLED) and the first transistor (M1) connected between the initialization power source (Vint), and the i (i is a natural number) scan line (Si) and the anode electrode of the organic light emitting diode (OLED). A capacitor Cb is provided.

The organic light emitting diode (OLED) generates light having a predetermined luminance corresponding to the amount of current supplied from the pixel circuit 142.

The pixel circuit 142 initializes the gate electrode voltage of the driving transistor (not shown) using the initialization power source Vint. Then, the pixel circuit 142 receives a data signal from the data line Dm when the scan signal is supplied to the j-th scan line Sj, and stores the supplied data signal. The pixel circuit 142 storing the data signal controls the amount of current flowing from the first power supply ELVDD to the second power supply ELVSS via the organic light emitting diode OLED in response to the data signal. The pixel circuit 142 of the present invention may be implemented as various types of circuits receiving the initialization power Vint.

The first transistor M1 is connected between the anode electrode of the organic light emitting diode OLED and a fixed voltage source. Here, the fixed voltage source is set to a voltage lower than the data signal, and may be set to the second power supply ELVSS or the initialization power supply Vint. Hereinafter, for convenience of description, it is assumed that the first transistor M1 is connected to the initialization power source Vint.

The first transistor M1 is turned on when the scan signal is supplied to the i-th scan line Si to supply the voltage of the initialization power source Vint to the anode electrode of the organic light emitting diode OLED. When the voltage of the initialization power source Vint is supplied to the anode electrode of the organic light emitting diode OLED, the organic capacitor formed parasitic on the organic light emitting diode OLED is discharged.

Here, when the organic capacitor (Coled) is initialized, when the black luminance is implemented, the organic light emitting diode (OLED) is set to the non-light emitting state by the leakage current supplied from the pixel circuit 142. In other words, when the black luminance is implemented, the organic light emitting diode OLED is set to the non-light emitting state during a period in which the organic capacitor is charged by the leakage current supplied from the pixel circuit 142.

Additionally, the i-th scan line Si is selected as one of the scan lines S1 to Sn corresponding to the structure of the pixel circuit 142. For example, as the i-th scan line Si, the Sj-1 scan line Sj-1 or the Sj + 1 scan line Sj + 1 may be selected.

The boosting capacitor Cb is connected between the anode electrode of the organic light emitting diode OLED and the i-th scan line Si. The boosting capacitor Cb raises the anode electrode voltage of the organic light emitting diode OLED below the turn-on voltage of the organic light emitting diode after the supply of the scan signal to the i-th scan line Si is stopped. In other words, the boosting capacitor Cb raises the anode electrode voltage of the organic light emitting diode OLED to a voltage higher than the initialization power source Vint.

In detail, when the organic light emitting diode OLED is set to the voltage of the initializing power source Vint, it is possible to prevent the organic light emitting diode OLED from emitting light due to the leakage current from the pixel circuit 142. However, even when a low current corresponding to low gradation is supplied from the pixel circuit 142 to the organic light emitting diode (OLED), the organic light emitting diode (OLED) does not emit light until a predetermined time, that is, the time when the organic capacitor is charged. Maintaining the state does not achieve the desired luminance at low gradations.

Therefore, in the present invention, the anode electrode of the organic light emitting diode (OLED) is raised by using the boosting capacitor (Cb) so that the desired luminance can be realized at low gradation. Here, the anode electrode voltage of the organic light emitting diode (OLED) rising from the boosting capacitor (Cb) is non-emitted by the leakage current supplied from the pixel circuit 142 when realizing black luminance, and emits light by a current corresponding to low gradation It is determined experimentally to be. For example, by controlling the capacity of the boosting capacitor Cb, the rising width of the anode electrode voltage of the organic light emitting diode OLED can be controlled.

In fact, when the black luminance is implemented, since the driving transistor included in the pixel circuit 142 is set to the turn-off state, a low amount of current is supplied to the organic light emitting diode OLED as a leakage current. Therefore, even if the organic light emitting diode OLED is raised below the turn-on voltage by the boosting capacitor Cb, the organic light emitting diode OLED maintains a non-emission state. On the other hand, since the driving transistor included in the pixel circuit 142 is set to a turn-on state when implementing low grayscale, a greater amount of current is supplied to the organic light emitting diode (OLED) than the leakage current supplied when implementing black. Accordingly, when the organic light emitting diode OLED is raised below the turn-on voltage by the boosting capacitor Cb, it is possible to stably implement low gradation luminance.

3 is a diagram illustrating an embodiment of the pixel circuit shown in FIG. 2. In FIG. 3, it is assumed that the i-th scan line Si is the j-th scan line Sj-1.

Referring to FIG. 3, a pixel circuit 142 according to an embodiment of the present invention includes second transistors M2 to 7 transistors M7 and a storage capacitor Cst.

The first electrode of the fifth transistor M5 is connected to the data line Dm, and the second electrode is connected to the first node N1. The gate electrode of the fifth transistor M5 is connected to the j-th scan line Sj. The fifth transistor M5 is turned on when the scan signal is supplied to the j-th scan line Sj to supply the data signal from the data line Dm to the first node N1.

The first electrode of the second transistor (M2: driving transistor) is connected to the first node N1, and the second electrode is connected to the first electrode of the seventh transistor M7. Further, the gate electrode of the second transistor M2 is connected to the second node N2. The second transistor M2 controls the amount of current flowing from the first power supply ELVDD to the second power supply ELVSS through the organic light emitting diode OLED in response to the voltage charged in the storage capacitor Cst.

The first electrode of the third transistor M3 is connected to the second node N2, and the second electrode is connected to the initialization power source Vint. Further, the gate electrode of the third transistor M3 is connected to the j-1 scan line Sj-1. The third transistor M3 is turned on when the scan signal is supplied to the j-1 scan line Sj-1 to supply the voltage of the initialization power supply Vint to the second node N2. Here, the initialization power supply Vint is set to a voltage lower than the data signal.

The first electrode of the fourth transistor M4 is connected to the second electrode of the second transistor M2, and the second electrode is connected to the second node N2. Then, the gate electrode of the fourth transistor M4 is connected to the j-th scan line Sj. The fourth transistor M4 is turned on when the scan signal is supplied to the j-th scan line Sn to connect the second transistor M2 in the form of a diode.

The first electrode of the sixth transistor M6 is connected to the first power supply ELVDD, and the second electrode is connected to the first node N1. The gate electrode of the sixth transistor M6 is connected to the emission control line Ej. The sixth transistor M6 is turned off when the emission control signal is supplied to the emission control line Ej, and turned on when the emission control signal is not supplied.

The first electrode of the seventh transistor M7 is connected to the second electrode of the second transistor M2, and the second electrode is connected to the anode electrode of the organic light emitting diode OLED. The gate electrode of the seventh transistor M7 is connected to the emission control line Ej. The seventh transistor M7 is turned off when the emission control signal is supplied to the emission control line Ej, and turned on when the emission control signal is not supplied.

4 is a waveform diagram illustrating a method of driving a pixel illustrated in FIG. 3.

Referring to FIG. 4, first, a scan signal is supplied to the j-1 scan line Sj-1, so that the first transistor M1 and the third transistor M3 are turned on.

When the third transistor M3 is turned on, the voltage of the initialization power source Vint is supplied to the second node N2. When the first transistor M1 is turned on, the voltage of the initialization power source Vint is supplied to the anode electrode of the organic light emitting diode OLED. When the voltage of the initial rotation source (Vint) is supplied to the anode electrode of the organic light emitting diode (OLED), the organic capacitor (Coled) is initialized.

Meanwhile, the emission control signal is not supplied to the emission control line Ej during the first period T1 of the period in which the scanning signal is supplied to the j-1 scan line Sj-1, and accordingly, the sixth transistor M6 And the seventh transistor M7 remains turned on. When the sixth transistor M6 is turned on, the first power ELVDD is supplied to the first node N1. At this time, since the voltage of the initialization power source Vint is supplied to the second node N2, the second transistor M2 is initialized to the on bias state. That is, during the first period T1, the second transistor M2 is initialized to the on-bias state regardless of the data signal of the previous period, and accordingly, an image of uniform luminance can be displayed.

In addition, the current flowing from the second transistor M2 during the first period T1 is supplied to the initialization power Vint via the seventh transistor M7 and the first transistor M1. Therefore, during the first period T1, the organic light emitting diode OLED maintains a non-emission state.

Thereafter, the emission control signal is supplied to the emission control line Ej during the second period T2 of the period during which the scanning signal is supplied to the j-1 scan line Sj-1. When the emission control signal is supplied to the emission control line Ej, the sixth transistor M6 and the seventh transistor M7 are turned off. When the sixth transistor M6 is turned off, the first power supply ELVDD and the first node N1 are electrically cut off. When the seventh transistor M7 is turned off, the second transistor M2 and the organic light emitting diode OLED are electrically blocked. During the second period T2, the voltage of the initialization power supply Vint is supplied to the second node N2 and the anode electrode of the organic light emitting diode OLED.

Subsequently, the supply of the scan signal to the j-1 scan line Sj-1 is stopped, and the first transistor M1 and the third transistor M3 are turned off. Then, when the supply of the scan signal to the j-1 scan line Sj-1 is stopped, the j-1 scan line Sj-1 rises from a low voltage to a high voltage. At this time, the boosting capacitor Cb increases the anode electrode voltage of the organic light emitting diode OLED in response to the voltage increase of the j-1 scan line Sj-1.

In the third period T3, a scan signal is supplied to the j-th scan line Sj. When the scan signal is supplied to the j-th scan line Sj, the fourth transistor M4 and the fifth transistor M5 are turned on.

When the fourth transistor M4 is turned on, the second transistor M2 is connected in the form of a diode. When the fifth transistor M5 is turned on, a data signal from the data line Dm is supplied to the first node N1. At this time, since the second node N2 is initialized with the voltage of the initialization power source Vint, the second transistor M2 is turned on. When the second transistor M2 is turned on, a voltage obtained by subtracting the threshold voltage of the second transistor M2 from the voltage of the data signal applied to the first node N1 is supplied to the second node N2. At this time, the storage capacitor Cst stores the voltage applied to the second node N2.

After the storage capacitor Cst is charged with a predetermined voltage, the supply of the emission control signal to the emission control line Ej is stopped for the fourth period T4, so that the sixth transistor M6 and the seventh transistor M7 are turned. -It comes on. When the sixth transistor M6 and the seventh transistor M7 are turned on, a current path is formed from the first power source ELVDD to the second power source ELVSS via the organic light emitting diode OLED. At this time, the second transistor M2 controls the amount of current flowing from the first power supply ELVDD to the organic light emitting diode OLED in response to the voltage charged in the storage capacitor Cst.

Meanwhile, when black luminance is implemented during the fourth period T4, a predetermined leakage current is supplied from the pixel circuit 142 to the anode electrode of the organic light emitting diode (OLED). At this time, since the organic capacitor (Coled) is initialized, the organic light emitting diode (OLED) is set to the non-light emitting state in response to the leakage current of black.

In addition, when the low grayscale is implemented during the fourth period T4, a predetermined current is supplied from the pixel circuit 142 to the anode electrode of the organic light emitting diode (OLED). Here, the low gradation current has a higher current amount than the black leakage current, and accordingly, the organic capacitor (Coled) is easily charged. In addition, since the anode electrode voltage of the organic light emitting diode (OLED) is increased by the boosting capacitor (Cb), the organic light emitting diode (OLED) is stably set to a light emission state in response to a low gradation current.

Additionally, during the fourth period, the first transistor M1 provides a path through which the leakage current can flow from the organic light emitting diode OLED to the initialization power source Vint. Here, when the organic light emitting diode (OLED) emits light, a lot of current is supplied to the organic light emitting diode (OLED), and accordingly, the leakage current hardly affects the luminance. On the other hand, when realizing black gradation, a fine current is supplied from the pixel circuit 142 to the organic light emitting diode (OLED). In this case, the leakage current of the first transistor M1 greatly affects the light emission of the organic light emitting diode OLED. In fact, in the case of implementing the gray level of black, it is possible to prevent the emission of the organic light emitting diode OLED by the leakage current of the first transistor M1.

5 is a graph showing a voltage change of the gate electrode of the driving transistor corresponding to the voltage change of the second power source. In FIG. 5, the solid line of the second power supply ELVSS represents a voltage of approximately -3V, and the dotted line represents a voltage of approximately -4V. That is, the solid line and the dotted line of the second power source ELVSS indicate the voltage change of the second power source ELVSS. In addition, the solid lines and dotted lines of Vanode and M2_gat1 represent the anode electrode voltage change (Vanode) of the organic light emitting diode (OLED) and the gate electrode voltage change of the driving transistor (M2) corresponding to the voltage change of the second power source (ELVSS).

Referring to FIG. 5, a parasitic capacitor (not shown) is formed between the anode electrode of the organic light emitting diode (OLED) and the gate electrode of the driving transistor M2. The parasitic capacitor changes the gate electrode voltage of the driving transistor M2 in response to the voltage change of the second power supply ELVSS.

Here, the second power source ELVSS has a different voltage value for each position of the pixel unit 130 due to a voltage drop or the like, and accordingly, the gate electrode voltage of the driving transistor M2 according to the formation position of each of the pixels 140. There is a problem of this non-uniformity. In particular, in the case of the pixel 140 that controls light emission or non-emission of the pixels 140 using the second power source ELVSS, the gate electrode voltage unevenness of the driving transistor M2 is intensified.

However, when the anode electrode voltage of the organic light emitting diode (OLED) is increased by using the boosting capacitor (Cb) as in the present invention, the anode electrode of the organic light emitting diode (OLED) and the voltage change of the second power source (ELVSS) The voltage change of the gate electrode of the driving transistor M2 is minimized. In other words, since the anode electrode of the organic light emitting diode (OLED) rises to a specific voltage by the boosting capacitor (Cb), the voltage change by the second power source (ELVSS) can be minimized when the organic light emitting diode (OLED) emits light. .

That is, in the present invention, since the voltage of the organic light emitting diode (OLED) is increased by using the boosting capacitor (Cb), the image of the desired luminance is displayed at the low gray level and the driving transistor (M2) by the second power supply (ELVSS) It has an advantage of minimizing the voltage change of the gate electrode.

Meanwhile, in the above-described present invention, transistors are shown as PMOS for convenience of explanation, but the present invention is not limited thereto. In other words, the transistors may be formed of NMOS.

In addition, in the present invention, the organic light emitting diode (OLED) may generate red, green, or blue light or generate white light in response to an amount of current. When the organic light emitting diode (OLED) generates white light, a color image may be implemented using a separate color filter or the like.

It should be noted that, although the technical spirit of the present invention has been specifically described according to the above preferred embodiment, the above embodiment is for the purpose of explanation and not for the limitation. In addition, those skilled in the art of the present invention will understand that various modifications are possible within the scope of the technical spirit of the present invention.

110: scan driver 120: data driver
130: pixel unit 140: pixel
142: pixel circuit 150: timing control

Claims (14)

An organic light emitting diode having a cathode electrode connected to a second power source;
A pixel circuit including a driving transistor which is connected to the j (j is a natural number) scan line and a data line and controls the amount of current flowing from the first power supply to the second power supply through the organic light emitting diode;
A first transistor connected between a voltage source and an anode electrode of the organic light emitting diode and turned on when a scan signal is supplied to the i (i is a natural number) scan line;
And a boosting capacitor connected between the i-th scan line and the anode electrode of the organic light emitting diode,
The i-th scan line is a pixel, characterized in that it is set to the j-1 scan line. According to claim 1,
A pixel having an initializing voltage lower than that of the data signal supplied to the data line before the scan signal is supplied to the j-th scan line to the gate electrode of the driving transistor. According to claim 2,
The voltage source is set to the second power source or the initializing power source. According to claim 1,
The voltage source is set to a voltage lower than the data signal supplied to the data line. delete According to claim 1,
The pixel circuit
A driving transistor for controlling the amount of current supplied to the organic light emitting diode from the first power supply connected via the first node corresponding to the voltage of the second node;
A fifth transistor positioned between the data line and the first node and turned on when a scan signal is supplied to the j-th scan line;
A third transistor connected between the second node and an initialization power source and turned on when a scan signal is supplied to the j-1 scan line;
And a fourth transistor connected between the second node and the second electrode of the driving transistor and turned on when a scan signal is supplied to the j-th scan line. The method of claim 6,
The pixel circuit
A sixth transistor connected between the first node and the first power source, turned on when the light emission control signal is supplied to the jth emission control line, and turned on in other cases;
The seventh transistor is connected between the anode electrode of the organic light emitting diode and the second electrode of the driving transistor, and is turned off when a light emission control signal is supplied to the j emission control line and turned on in other cases. A pixel further comprising. A scan driver for supplying a scan signal to the scan lines and a light emission control signal to the light emission control lines;
A data driver for supplying data signals to data lines;
Pixels located in an area partitioned by the scan lines and the data lines;
Each of the pixels positioned on the j (j is a natural number) horizontal line
An organic light emitting diode having a cathode electrode connected to a second power source;
A pixel circuit connected to the j-th scan line and the data line, the pixel circuit including a driving transistor controlling an amount of current flowing from the first power supply to the second power supply through the organic light emitting diode;
A first transistor connected between a voltage source set at a voltage lower than the data signal and the anode electrode of the organic light emitting diode, and turned on when a scan signal is supplied to the i (i is a natural number) scan line;
And a boosting capacitor connected between the i-th scan line and the anode electrode of the organic light emitting diode,
The i-th scan line is set to the j-1 scan line. The method of claim 8,
An organic electroluminescence display device characterized in that a voltage having an initializing power lower than that of the data signal is supplied to the gate electrode of the driving transistor before the scanning signal is supplied to the j-th scan line. The method of claim 9,
The voltage source is an organic light emitting display device, characterized in that is set to the second power or the initializing power. delete The method of claim 8,
The scan driving unit overlaps the scanning signal supplied to the j-1 scan line for a period of time and supplies an emission control signal to the j emission control line so as to completely overlap the scan signal supplied to the j scan line. Electroluminescent display device. The method of claim 12,
The pixel circuit
A driving transistor for controlling the amount of current supplied from the first power source connected to the organic light emitting diode via the first node in response to the voltage of the second node;
A fifth transistor positioned between the data line and the first node and turned on when a scan signal is supplied to the j-th scan line;
A third transistor connected between the second node and an initialization power source and turned on when a scan signal is supplied to the j-1 scan line;
And a fourth transistor connected between the second node and the second electrode of the driving transistor and turned on when a scan signal is supplied to the j-th scan line. The method of claim 13,
The pixel circuit
A sixth transistor connected between the first node and the first power source and turned off when a light emission control signal is supplied to the jth emission control line, and turned on in other cases;
The seventh transistor is connected between the anode electrode of the organic light emitting diode and the second electrode of the driving transistor, and is turned off when the light emission control signal is supplied to the j emission control line and turned on in other cases. An organic light emitting display device further comprising.

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