KR100707628B1 - Light Emitting Display and Driving Method Thereof - Google Patents

Abstract

The present invention relates to a light emitting display device capable of preventing motion blur.

A light emitting display device according to the present invention comprises: a scan driver for sequentially supplying scan signals to scan lines and sequentially supplying light emission control signals to light emission control lines; A data driver for supplying a data signal to the data lines; An image display unit including pixels connected to the scan line, the emission control line, and the data line to generate light corresponding to the data signal and whose light generation time is controlled by the emission control signal; The scan driver provides a light emitting display device which supplies the light emission control signal to all the light emission control lines so that a black screen can be displayed during at least one frame period of a plurality of frames.

By such a configuration, the present invention can prevent the motion blur phenomenon from occurring.

Description

Light Emitting Display and Driving Method Thereof

1 is a view showing a general light emitting device.

2 is a view showing a light emitting display device according to an embodiment of the present invention;

FIG. 3 is a waveform diagram showing driving waveforms supplied to the scanning line, data line and emission control line shown in FIG.

4 is a circuit diagram showing a first embodiment of the pixel shown in FIG.

5A and 5B are diagrams showing light emission control signals supplied from a scan driver.

FIG. 6 is a circuit diagram showing a second embodiment of the pixel shown in FIG. 2; FIG.

<Explanation of symbols for the main parts of the drawings>

20: anode electrode 21: cathode electrode

110: scan driver 120: data driver

130: image display unit 140: pixels

142: pixel circuit 150: timing controller

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting display device and a driving method thereof, and more particularly, to a light emitting display device and a driving method thereof capable of preventing a motion blur phenomenon.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes. The flat panel display includes a liquid crystal display, a field emission display, a plasma display panel, a light emitting display, and the like.

Among flat panel display devices, the light emitting display device includes a plurality of light emitting devices, and the light emitting devices generate predetermined light by recombination of electrons and holes. Such a light emitting display device has an advantage in that it has a fast response speed and is driven with low power consumption.

1 is a view showing a conventional general light emitting device.

Referring to FIG. 1, the light emitting device includes an emission layer (EL), a hole transfer layer (HTL), and an electron transport layer (ETL) formed between the anode electrode 20 and the cathode electrode 21. ).

The anode electrode 20 is connected to the first power source to supply holes to the light emitting layer EL. The cathode electrode 21 is connected to a second power source lower than the first power source to supply electrons to the light emitting layer EL. That is, the anode electrode 20 has a higher potential of positive polarity (+) than the cathode electrode 21, and the cathode electrode 21 has a relatively low polarity (−) than the anode electrode 20. Has a potential.

The hole transport layer HTL accelerates holes supplied from the anode electrode 20 and supplies them to the light emitting layer EL. The electron transport layer ETL accelerates and supplies electrons supplied from the cathode electrode 21 to the emission layer EL. Holes supplied from the hole transport layer HTL and electrons supplied from the electron transport layer ETL recombine in the emission layer EL. At this time, predetermined light is generated in the light emitting layer EL. Subsequently, the emission layer EL is formed of an organic material to generate light of one of red (R), green (G), and blue (B) when electrons and holes recombine.

Meanwhile, the light emitting device includes a hole injection layer (HIL) located between the hole transport layer (HTL) and the anode electrode 20, and an electron injection layer located between the electron transport layer (ETL) and the cathode electrode 21. (Electron Injection Layer: EIL) is further included. The hole injection layer HIL supplies holes to the hole transport layer HTL. The electron injection layer EIL supplies electrons to the electron transport layer ETL.

Such a light emitting device is provided for each pixel of the light emitting display to generate a predetermined light corresponding to the current supplied to the light emitting device. Here, each pixel is equipped with at least one capacitor for supplying current to the light emitting element during the time of each frame. That is, in the conventional light emitting display device, a predetermined voltage is charged in a capacitor provided for each pixel, and a predetermined current is supplied to the light emitting device by using the charged voltage.

However, as shown in the related art, when a predetermined image is displayed on a pixel during each frame period by using a voltage charged in a capacitor, a motion blur phenomenon occurs. That is, when the current corresponding to the voltage charged in the capacitor is continuously supplied to the light emitting device during each frame period, a motion blur phenomenon occurs in which the image is blurred due to the afterimage effect of eyes when displaying a moving image. When such a motion blur occurs, the display quality of the light emitting display device is degraded.

Accordingly, an object of the present invention is to provide a light emitting display device and a driving method thereof capable of preventing a motion blur phenomenon.

In order to achieve the above object, the first aspect of the present invention includes a scan driver for sequentially supplying the scanning signal to the scanning lines, and sequentially supplying the emission control signal to the emission control lines; A data driver for supplying a data signal to the data lines; An image display unit including pixels connected to the scan line, the emission control line, and the data line to generate light corresponding to the data signal and whose light generation time is controlled by the emission control signal; The scan driver provides a light emitting display device which supplies the light emission control signal to all the light emission control lines so that a black screen can be displayed during at least one frame period of a plurality of frames.

Preferably, the plurality of frames are frames included in one second. Each of the pixels may include a first transistor connected to an nth (n is a natural number) scan line and a data line, a storage capacitor for charging a voltage corresponding to the data signal when the first transistor is turned on, and the storage capacitor. A second transistor for controlling a current supplied to the light emitting element in response to the voltage charged in the second; and connected between the second transistor and the light emitting element and turned off when the light emission control signal is supplied to the light emitting control line. And a third transistor which is otherwise turned on.

According to a second aspect of the present invention, there is provided a method of supplying a data signal to pixels selected by a scanning signal, supplying a current corresponding to the data signal to a light emitting device included in each of the pixels, and emitting light control lines. And controlling a supply time of the current supplied to the light emitting element in response to the light emission control signal supplied, wherein the black screen is displayed on at least one specific frame among a plurality of frames. A driving method of a light emitting display device which supplies the light emission control signal to all the light emission control lines is provided.

Preferably, the plurality of frames are frames included in one second.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 2 to 6 that can be easily implemented by those skilled in the art.

2 is a diagram illustrating a light emitting display device according to an exemplary embodiment of the present invention.

Referring to FIG. 2, a light emitting display device according to an exemplary embodiment of the present invention includes an image display unit 130 including pixels 140 formed at an intersection area of scan lines S1 to Sn and data lines D1 to Dm. And the scan driver 110 for driving the scan lines S1 to Sn, the data driver 120 for driving the data lines D1 to Dm, the scan driver 110 and the data driver 120. A timing controller 150 for controlling is provided.

The timing controller 150 generates a data drive control signal DCS and a scan drive control signal SCS using a synchronization signal supplied from the outside. The data driving control signal DCS generated by the timing controller 150 is supplied to the data driver 120, and the scan driving control signal SCS is supplied to the scan driver 110. The timing controller 150 supplies the data Data supplied from the outside to the data driver 120.

The scan driver 110 receives the scan driving control signal SCS from the timing controller 150. The scan driver 110 supplied with the scan driving control signal SCS sequentially supplies the scan signals to the first scan line S1 to the nth scan line Sn as shown in FIG. 3. The scan driver 110 supplied with the scan driving control signal SCS sequentially supplies the emission control signal to the first emission control line E1 to the nth emission control line En. Here, the width of the light emission control signal is set equal to the width of the scan signal or wider than the width of the scan signal. For example, the light emission control signal may be supplied to overlap two scan signals.

Meanwhile, the scan driver 110 of the present invention commonly controls light emission with all emission control lines E1 to En during at least one specific frame period among a plurality of frames (eg, 60Fs included in one second). Supply the signal. As such, when the emission control signal is supplied to all the emission control lines during the specific frame period, the black display is displayed on the image display unit 130. Detailed description thereof will be described later.

The data driver 120 receives the data drive control signal DCS from the timing controller 150. The data driver 120 receiving the data driving control signal DCS supplies the data signal DS to the data lines D1 to Dm whenever the scan signal is supplied as shown in FIG. 3.

The image display unit 130 receives the first power source ELVDD and the second power source ELVSS. The first power source ELVDD and the second power source ELVSS supplied to the image display unit 130 are supplied to the respective pixels 140.

4 is a diagram illustrating a first embodiment of the pixel illustrated in FIG. 2. In FIG. 4, pixels connected to the nth scan line Sn and the mth data line Dm will be illustrated for convenience of description.

Referring to FIG. 4, the pixel 140 of the present invention is connected to the light emitting device OLED, the light emitting device OLED, the data line Dm, the light emission control line En, and the scanning line Sn, so that the light emitting device ( A pixel circuit 142 for emitting the OLED).

The anode of the light emitting device OLED is connected to the pixel circuit 142, and the cathode is connected to the second power source ELVSS. The light emitting device OLED generates light corresponding to a current supplied from the pixel circuit 142.

The pixel circuit 142 includes a second transistor M2 and a third transistor M3, a second transistor M2, a data line Dm, and a second transistor M2 connected between the first power source ELVDD and the light emitting device OLED. The first transistor M1 is connected between the scan lines Sn, and the storage capacitor C is connected between the gate electrode of the second transistor M2 and the first power source ELVDD.

The gate electrode of the first transistor M1 is connected to the scan line Sn, and the first electrode is connected to the data line Dm. The second electrode of the first transistor M1 is connected to one side of the storage capacitor C and the gate electrode of the second transistor M2. The first transistor M1 is turned on when the scan signal is supplied from the scan line Sn to supply the data signal supplied from the data line Dm to the storage capacitor C. At this time, the storage capacitor C is charged with a voltage corresponding to the data signal.

The gate electrode of the second transistor M2 is connected to one side of the storage capacitor C, and the first electrode is connected to the first power source ELVDD. The second electrode of the second transistor M2 is connected to the first electrode of the third transistor M3. The second transistor M2 controls the amount of current flowing from the first power supply ELVDD to the light emitting device OLED in response to the voltage stored in the storage capacitor C.

The gate electrode of the third transistor M3 is connected to the emission control line En, and the first electrode is connected to the second electrode of the second transistor M2. The second electrode of the third transistor M3 is connected to the light emitting element OLED. The third transistor M3 is turned on when the emission control signal is not supplied to supply the current supplied from the second transistor M2 to the light emitting device OLED. That is, the third transistor M3 controls the supply time of the current supplied from the second transistor M2 to the light emitting device OLED.

5A and 5B are diagrams illustrating light emission control signals supplied from a scan driver.

5A and 5B, the scan driver 110 of the present invention controls all light emission during at least one specific frame period of a plurality of frames (for example, frames included in one second 1S). The emission control signal is commonly supplied to the lines E1 to En. Here, when the emission control signal is commonly supplied to all the emission control lines E1 to En, the third transistor M3 included in each of the pixels 140 is turned off to not supply current to the light emitting device OLED. Therefore, the motion blur phenomenon can be prevented in the image display unit 130.

In detail, when the emission control signal is supplied to all the emission control lines E1 to En during a specific frame period, the third transistor M3 included in each of the pixels 140 is set to a turn-off state. Here, when the third transistor M3 is set to the turn-off state, current is not supplied to the light emitting diode OLED during a specific frame period, and thus a black screen is displayed on the light emitting display device. That is, in the present invention, light is generated in the pixels 140 during a specific frame period among the plurality of frames, thereby preventing motion blur.

On the other hand, the scan driver 110 sequentially supplies the emission control signal to the first emission control line E1 to the nth emission control line En for the remaining frame periods except for the specific frame. As described above, in the frame in which the emission control signal is sequentially supplied to the first emission control line E1 to the nth emission control line En, a predetermined image is displayed on the image display unit 130.

FIG. 6 is a diagram illustrating a second embodiment of the pixel illustrated in FIG. 2.

Referring to FIG. 6, the pixel 140 according to the second exemplary embodiment of the present invention is connected to the light emitting device OLED, the data line Dm, the scanning line Sn, and the light emission control line En so that the light emitting device ( And a pixel circuit 142 for emitting OLEDs.

The anode of the light emitting device OLED is connected to the pixel circuit 142, and the cathode is connected to the second power source ELVSS. The light emitting device OLED generates light corresponding to a current supplied from the pixel circuit 142.

The pixel circuit 142 includes a storage capacitor C and a sixth transistor M6 connected between the first power source ELVDD and the n-1 th scan line Sn-1, the first power source ELVDD and the data line. The first and fourth transistors M1 and M4 connected between the first and second transistors M3 and M3 connected to the light emitting element OLED and the emission control line En, and the first node N1. ) And a second transistor M2 connected between the third transistor M3 and a fifth transistor M5 connected between the gate electrode and the second electrode of the second transistor M2.

The first electrode of the second transistor M2 is connected to the first node N1, and the second electrode is connected to the first electrode of the third transistor M3. The gate electrode of the second transistor M2 is connected to the storage capacitor C. The second transistor M2 supplies a current corresponding to the voltage charged in the storage capacitor C to the light emitting device OLED.

The fifth transistor M5 is connected between the second electrode and the gate electrode of the second transistor M2. The gate electrode of the fifth transistor M5 is turned on when the scan signal is supplied to the nth scan line Sn to connect the second transistor M2 in the form of a diode. That is, when the fifth transistor M5 is turned on, the second transistor M2 is connected in the form of a diode.

The first electrode of the first transistor M1 is connected to the data line Dm, and the second electrode is connected to the first node N1. The gate terminal of the first transistor M1 is connected to the nth scan line Sn. The first transistor M1 is turned on when the scan signal is supplied to the nth scan line Sn and supplies the data signal supplied to the data line D to the first node N1.

The second electrode of the fourth transistor M4 is connected to the first node N1, and the first electrode is connected to the first power source ELVDD. The gate electrode of the fourth transistor M4 is connected to the emission control line En. The fourth transistor M4 is turned on when the emission control signal is not supplied to electrically connect the first power supply ELVDD and the first node N1.

The first electrode of the third transistor M3 is connected to the second electrode of the second transistor M2, and the second electrode is connected to the light emitting device OLED. The gate terminal of the third transistor M3 is connected to the light emission control line En. The third transistor M3 is turned on when the emission control signal is not supplied to supply the current supplied from the second transistor M2 to the light emitting device OLED.

The first electrode of the sixth transistor M6 is connected to the storage capacitor C, and the second electrode and the gate electrode are connected to the n−1 th scan line Sn−1. The sixth transistor M6 is turned on when the scan signal is supplied to the n-1 th scan line Sn-1 to initialize the gate electrodes of the storage capacitor C and the second transistor M2.

The operation process will be described in detail. First, the sixth transistor M6 is turned on by the scan signal supplied to the n−1 th scan line Sn−1. When the sixth transistor M6 is turned on, the scan signal supplied to the n-1 th scan line Sn-1 is supplied to the gate electrode and the storage capacitor C of the second transistor M2. In this case, the gate electrode and the storage capacitor C of the second transistor M2 are initialized by the voltage value of the scan signal.

Thereafter, the first transistor M1 and the fifth transistor M5 are turned on by the scan signal supplied to the nth scan line Sn. When the first transistor M1 is turned on, the data signal supplied to the data line Dm is supplied to the first node N1. At this time, since the second transistor M2 is connected in the form of a diode, the data signal supplied to the first node N1 is supplied to the storage capacitor C via the second transistor M2 and the fifth transistor M5. do. At this time, the storage capacitor C is charged with a threshold voltage of the second transistor M2 and a voltage corresponding to the data signal.

On the other hand, the fourth transistor M4 and the third transistor M3 are turned off by the light emission control signal during the period in which the scan signal is supplied to the n-1 th scan line Sn-1 and the n th scan line Sn. . After the storage capacitor C is charged with a voltage corresponding to the data signal and the threshold voltage of the second transistor M2, the supply of the emission control signal is stopped, so that the fourth transistor M4 and the third transistor M3 are stopped. Is turned on. Then, a current corresponding to the voltage charged in the storage capacitor C is supplied from the second transistor M2 to the light emitting element OLED to display a predetermined image.

In the present invention, since the light emission control signal is continuously supplied to the fourth transistor M4 and the fifth transistor M5 for a specific frame period, no current is supplied to the light emitting element OLED during the specific frame period. Therefore, in the present invention, a black screen is displayed for a specific frame period, and thus a motion blur phenomenon can be prevented. On the other hand, the pixel of the present invention is not limited to the structure shown in Figs. 4 and 6, it can be set to various pixels having a transistor connected to the emission control line.

The above detailed description and drawings are merely exemplary of the present invention, which are used only for the purpose of illustrating the present invention and are not intended to limit the scope of the present invention as defined in the claims or the claims. Accordingly, those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical protection scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

As described above, according to the light emitting display device and the driving method thereof, the emission time of the pixels is limited by supplying the emission control signal to all the emission control lines during at least one specific frame period of the plurality of frames. do. That is, the present invention can prevent the motion blur from occurring by displaying a black screen in pixels during a specific frame period.

Claims (6)

A scan driver for sequentially supplying scan signals to scan lines and sequentially supplying light emission control signals to light emission control lines; A data driver for supplying a data signal to the data lines; An image display unit including pixels connected to the scan line, the emission control line, and the data line to generate light corresponding to the data signal and whose light generation time is controlled by the emission control signal; And the scan driver supplies the light emission control signal to all of the light emission control lines to display a black screen for at least one frame period of a plurality of frames. The method of claim 1, Wherein the plurality of frames are frames included in one second. The method of claim 1, Each of the pixels A first transistor connected to an nth (n is a natural number) scan line and a data line, A storage capacitor for charging a voltage corresponding to the data signal when the first transistor is turned on; A second transistor for controlling a current supplied to the light emitting device in response to the voltage charged in the storage capacitor; And a third transistor connected between the second transistor and the light emitting element to be turned off when the light emission control signal is supplied to the light emission control line, and to be turned on elsewhere. The method of claim 3, Each of the pixels A fourth transistor connected between the second transistor and a first power source, the fourth transistor being turned on and off simultaneously with the third transistor; A fifth transistor connected between the gate electrode and the second electrode of the second transistor; And a sixth transistor connected to the gate electrode and the storage capacitor of the second transistor and turned on when the scan signal is supplied to the n-th scan line. Supplying a data signal to pixels selected by the scan signal; Supplying a current corresponding to the data signal to a light emitting device included in each of the pixels; Controlling a supply time of the current supplied to the light emitting element in response to a light emission control signal supplied to light emission control lines; A method of driving a light emitting display device, wherein the light emission control signal is supplied to all the light emission control lines during the specific frame period so that a black screen can be displayed on at least one specific frame among a plurality of frames. The method of claim 5, And the plurality of frames are frames included in one second.

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