CN101656043B - Pixel circuit, active matrix organic light emitting diode display and driving method - Google Patents

Abstract

The invention provides a pixel circuit, an active matrix organic light emitting diode display and a driving method. The driving transistor is used for generating pixel current according to the charge quantity stored in the storage capacitor so as to drive the organic light-emitting diode to generate corresponding brightness; the on/off states of the first to fourth switching transistors are controlled by the same scanning signal, and the pixel current flowing through the organic light emitting diode is independent of the power supply voltage and the threshold voltage of the driving transistor through the electrical coupling relationship of the first to fourth switching transistors and can be improved along with the rise of the cross voltage of the organic light emitting diode after long-time operation. The invention also provides an active matrix organic light-emitting diode display adopting the pixel circuit and a driving method of the pixel circuit.

Description

Pixel circuit, active matrix organic light emitting diode display and driving method

technical field

The invention relates to the technical field of organic light emitting diode display, and in particular to a pixel circuit, an active matrix organic light emitting diode display and a driving method.

Background technique

Pixels of an active matrix OLED (Organic Light Emitting Diode, OLED) display generally use transistors and storage capacitors to store charges to control the brightness of the OLED. Please refer to FIG. 1 , which is a schematic diagram of a conventional pixel circuit. The pixel circuit 200 includes a P-type driving transistor 202 , an N-type switching transistor 204 , a storage capacitor Cst, and an OLED 210 . The source S of the driving transistor 202 is electrically coupled to the power supply voltage OVDD; the gate G of the switching transistor 204 receives the scan signal SCAN due to the electrical coupling relationship, and the drain D receives the data voltage Vdata due to the electrical coupling relationship, The source S is electrically coupled to the gate of the driving transistor 202; the two ends of the storage capacitor Cst are connected between the gate G and the source S of the driving transistor 202, and the voltage across the capacitor is marked as V _sg ; the organic light emitting diode The anode of 210 is electrically coupled to the drain D of the driving transistor 202 , and the cathode is electrically coupled to another power supply voltage OVSS. The foregoing pixel structure controls the magnitude of the current flowing through the driving transistor 202 through the capacitor cross voltage V _sg , that is, the pixel current I _oled flowing through the organic light emitting diode 210 =K*(V _sg −V _TH ) ² ; where K is a constant, V The magnitude of _sg is related to the magnitude of the power supply voltage OVDD and the data voltage Vdata, and V _TH is the threshold voltage of the driving transistor 202 .

Because the power supply voltage OVDD on the active matrix organic light emitting diode display is connected together between each pixel, when the organic light emitting diode 210 is driven to light up, the power supply voltage OVDD metal line will have a current flow, and because the OVDD metal itself The line has impedance, so there will be a power supply voltage drop (IR-drop), which will cause a difference in the power supply voltage OVDD of each pixel, resulting in a difference in the pixel current I _oled between pixels, and the current flowing through the OLED is different. The resulting brightness will be different, resulting in uneven panel display. In addition, due to the influence of the manufacturing process, the threshold voltage _VTH of the driving transistor 202 of each pixel is different, so even if the same data voltage Vdata is given, the generated pixel current still varies, resulting in uneven panel display. In addition, the organic light emitting diode 210 will cause material attenuation as the usage time increases, so that the cross-voltage of the organic light emitting diode 210 will increase, which will cause the pixel current I _oled to decrease, and then cause the overall display brightness of the panel to decrease.

Contents of the invention

One of the objectives of the present invention is to provide a pixel circuit to improve the problem of uneven panel display and the problem of material attenuation of organic light emitting diodes.

Another object of the present invention is to provide an active matrix organic light emitting diode display, so as to improve the problems of panel display unevenness and material degradation of organic light emitting diodes.

Another object of the present invention is to provide a method for driving a pixel circuit, so as to improve the problem of uneven panel display and the problem of material attenuation of organic light emitting diodes.

A pixel circuit provided by an embodiment of the present invention includes: an organic light emitting diode, a storage capacitor, a driving transistor, a first switching transistor, a second switching transistor, a third switching transistor, and a fourth switching transistor. Wherein, the storage capacitor includes a first end and a second end; the driving transistor is used to drive the organic light emitting diode to light up, and its first source/drain is electrically coupled to the first end of the storage capacitor, and the second source/drain is electrically coupled to the first end of the storage capacitor. is electrically coupled to the organic light emitting diode; the gate of the first switching transistor receives the scan signal due to the electrical coupling relationship, its first source/drain is electrically coupled to a preset voltage, and the second source/drain is electrically Coupled to the first end of the storage capacitor; the gate of the second switching transistor receives the aforementioned scan signal due to the electrical coupling relationship, and its first source/drain is electrically coupled to the second end of the storage capacitor, and the second The source/drain is electrically coupled to the gate of the driving transistor; the gate of the third switch transistor receives the aforementioned scanning signal due to the electrical coupling relationship, and its first source/drain is electrically coupled to the first gate of the driving transistor. Two sources/drains, the second source/drain is electrically coupled to the gate of the driving transistor; the gate of the fourth switching transistor receives the aforementioned scanning signal due to the electrical coupling, and the first source/drain of it Electrically coupled to the second end of the storage capacitor, the second source/drain receives the data voltage due to the electrical coupling.

In an embodiment of the present invention, the on/off states of the aforementioned first switch transistor and the second switch transistor are opposite to the on/off states of the third switch transistor and the fourth switch transistor. Further, the first switch transistor and the second switch transistor may be P-type transistors, and the third switch transistor and the fourth switch transistor may be N-type transistors.

Another embodiment of the present invention provides an active matrix organic light emitting diode display, which includes: a data driving circuit, a scanning driving circuit and at least one pixel. Wherein, the pixel includes: an organic light emitting diode, a storage capacitor, a driving transistor, a first switching transistor, a second switching transistor, a third switching transistor and a fourth switching transistor. The storage capacitor includes a first end and a second end; the driving transistor is used to drive the organic light emitting diode to light up, and its first source/drain is electrically coupled to the first end of the storage capacitor, and the second source/drain is electrically coupled to the first end of the storage capacitor. connected to the organic light emitting diode; the gate of the first switching transistor is electrically coupled to the scanning driving circuit through the scanning line, the first source/drain is electrically coupled to a preset voltage, and the second source/drain is electrically coupled Connected to the first end of the storage capacitor; the gate of the second switching transistor is electrically coupled to the scan driving circuit through the aforementioned scan line, the first source/drain is electrically coupled to the second end of the storage capacitor, and the second The source/drain is electrically coupled to the gate of the driving transistor; the gate of the third switch transistor is electrically coupled to the scanning driving circuit through the scanning line, and the first source/drain is electrically coupled to the driving transistor. The second source/drain, the second source/drain is electrically coupled to the gate of the drive transistor; the gate of the fourth switch transistor is electrically coupled to the scan drive circuit through the aforementioned scan line, the first source/drain The electrode is electrically coupled to the second end of the storage capacitor, and the second source/drain is electrically coupled to the data driving circuit through the data line. Furthermore, the turn-on voltages of the gates of the first switch transistor and the second switch transistor are opposite to the turn-on voltages of the gates of the third switch transistor and the fourth switch transistor. Further, the first switch transistor and the second switch transistor may be P-type transistors, and the third switch transistor and the fourth switch transistor may be N-type transistors.

Yet another embodiment of the present invention provides a method for driving a pixel circuit. The pixel circuit includes an organic light emitting diode, a storage capacitor, and a driving transistor; the driving transistor is used to drive the organic light emitting diode to light up, and its first source/drain is electrically coupled It is connected to the first end of the storage capacitor, and the second source/drain is electrically coupled to the organic light emitting diode. Wherein, the driving method includes the steps of: providing a preset voltage to the first end of the storage capacitor, and making the second end of the storage capacitor communicate with the gate of the driving transistor; providing a data voltage to the second end of the storage capacitor, and making the storage capacitor The first terminal of the organic light emitting diode is discharged through the drive transistor and the organic light emitting diode until the conduction current of the organic light emitting diode is almost zero, so that the storage capacitor stores a charge; and then a preset voltage is provided to the first terminal of the storage capacitor and the The second end of the storage capacitor communicates with the gate of the driving transistor, so that the driving transistor generates pixel current according to the charge on the storage capacitor to drive the OLED to light up.

In an embodiment of the present invention, when the pixel further includes a first switch transistor and a second switch transistor, and the first source/drain of the first switch transistor is electrically coupled to a predetermined voltage, the first switch transistor of the first switch transistor The two sources/drains are electrically coupled to the first end of the storage capacitor, the first source/drain of the second switch transistor is electrically coupled to the second end of the storage capacitor, and the second source/drain of the second switch transistor When the polarity is electrically coupled to the gate of the drive transistor, the aforementioned step of providing a preset voltage to the first end of the storage capacitor and making the second end of the storage capacitor communicate with the gate of the drive transistor includes: turning on the first switch transistor and the second switch transistor.

In an embodiment of the present invention, when the pixel further includes a third switch transistor and a fourth switch transistor, and the first source/drain of the third switch transistor is electrically coupled to the second source/drain of the driving transistor, The second source/drain of the third switch transistor is electrically coupled to the gate of the drive transistor, the first source/drain of the fourth switch transistor is electrically coupled to the second end of the storage capacitor, and the fourth switch transistor When the second source/drain is electrically coupled to the data voltage, the aforementioned data voltage is provided to the second end of the storage capacitor, and the first end of the storage capacitor is discharged to the conduction of the OLED through the driving transistor and the OLED. The step of passing the current until it is almost zero so that the storage capacitor stores the charge includes: turning off the first switch transistor and the second switch transistor, and turning on the third switch transistor and the fourth switch transistor. Further, the aforementioned step of providing a preset voltage to the first end of the storage capacitor and connecting the second end of the storage capacitor to the gate of the driving transistor may further include: turning off the third switch transistor and the fourth switch transistor.

In an embodiment of the present invention, the on/off states of the aforementioned first switch transistor, second switch transistor, third switch transistor and fourth switch transistor are determined by the same control signal.

In an embodiment of the present invention, the aforementioned provides a predetermined voltage to the first end of the storage capacitor and connects the second end of the storage capacitor to the gate of the driving transistor, so that the driving transistor generates a voltage according to the charge on the storage capacitor. The step of driving the OLED by the pixel current includes: turning on the first switch transistor and the second switch transistor, and turning off the third switch transistor and the fourth switch transistor.

In the embodiment of the present invention, by designing the circuit structure of the pixel, the magnitude of the pixel current flowing through the OLED is related to the data voltage and the voltage across the OLED, but not related to the preset voltage and the threshold voltage of the driving transistor. Therefore, the pixel circuit, the active matrix organic light emitting diode display and the driving method of the pixel circuit proposed in the embodiments of the present invention can effectively improve the problem of panel display unevenness and the problem of material attenuation of organic light emitting diodes, so as to provide high-quality display images, And then reach the purpose of the present invention.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

FIG. 1 shows a schematic diagram of a conventional pixel circuit.

FIG. 2 illustrates an active matrix organic light emitting diode display related to an embodiment of the present invention.

FIG. 3 is a timing diagram of a driving method of a pixel circuit related to an embodiment of the present invention.

Figure number:

200: pixel circuit

202: P-type drive transistor

204: N-type switching transistor

210: Organic Light Emitting Diode

Cst: storage capacitor

G: grid

D: Drain

S: source

V _sg : Capacitive voltage across

SCAN: scan signal

Vdata: data voltage

I _oled : pixel current

OVDD, OVSS: supply voltage

100: Active Matrix Organic Light-Emitting Diode Display

102: Data drive circuit

103: data line

104: Scanning drive circuit

105: scan line

110: Organic Light Emitting Diode

M1: drive transistor

M2～M5: switching transistors

V _s1g1 : Capacitor voltage across

G1～G5: Gate

D1～D5: Drain

S1～S5: source

S1: first stage

S2: the second stage

S3: The third stage

L: low voltage level

H: high voltage level

Detailed ways

Referring to FIG. 2 , it illustrates an active matrix organic light emitting diode display related to an embodiment of the present invention. The active matrix organic light emitting diode display 100 includes a data driving circuit 102 , a scanning driving circuit 104 and a plurality of pixel circuits P, and only one pixel circuit P is shown in FIG. 2 as an example, but not intended to limit the present invention. As shown in FIG. 2, the data driving circuit 102 is used to provide the data voltage Vdata, and the scanning driving circuit 104 is used to provide the scanning signal SCAN; the pixel circuit P includes a storage capacitor Cst, a driving transistor M1, switching transistors M2-M5 and an organic light emitting diode 110 . The driving transistor M1 is used to drive the organic light emitting diode 110 to light up. The source S1 of the driving transistor M1 is electrically coupled to the terminal A of the storage capacitor Cst, and the drain D1 of the driving transistor M1 is electrically coupled to the organic light emitting diode 110. The anode of the organic light emitting diode 110 is electrically coupled to the power supply voltage OVSS. The gate G2 of the switch transistor M2 is electrically coupled to the scan line 105 (only one is shown in FIG. 2 as an example, but not intended to limit the present invention) to receive the scan signal SCAN from the scan driving circuit 104 through the scan line 105 , The source S2 of the switch transistor M2 is electrically coupled to another power supply voltage OVDD, and the drain D2 of the switch transistor M2 is electrically coupled to the terminal A of the storage capacitor Cst. The gate G3 of the switch transistor M3 is electrically coupled to the scan line 105 to receive the scan signal SCAN from the scan driving circuit 104 through the scan line 105, and the source S3 of the switch transistor M3 is electrically coupled to the terminal B of the storage capacitor Cst, The drain D3 of the switching transistor M3 is electrically coupled to the gate G1 of the driving transistor M1. The gate G4 of the switch transistor M4 is electrically coupled to the scan line 105 to receive the scan signal SCAN from the scan driving circuit 104 through the scan line 105, and the source S4 of the switch transistor M4 is electrically coupled to the drain D1 of the drive transistor M1. , the drain D4 of the switching transistor M4 is electrically coupled to the gate G1 of the driving transistor M1. The gate G5 of the switch transistor M5 is electrically coupled to the scan line 105 to receive the scan signal SCAN from the scan drive circuit 104 through the scan line 105, and the source S5 of the switch transistor M5 is electrically coupled to the terminal B of the storage capacitor. The drain D5 of the transistor M5 is electrically coupled to the data line 103 (only one is shown in FIG. 2 as an example, but not intended to limit the present invention) to receive the data voltage Vdata from the data driving circuit 102 through the data line 103 . In addition, the gate-on voltages (Gate-On Voltage) of the switch transistors M2 and M3 and the gate-on voltages of the switch transistors M4 and M5 are opposite to each other. For example, the switch transistors M2 and M3 are P-type transistors, and the switch transistors M4 and M5 are P-type transistors. M5 is an N-type transistor; correspondingly, the on/off states of the switch transistors M2 and M3 are opposite to the on/off states of the switch transistors M4 and M5.

The driving method of the pixel circuit of the active matrix organic light emitting diode display 100 will be described in detail below in conjunction with FIG. 2 and FIG. 3, wherein FIG. It can be known from the figure that the process of driving the pixel P includes a first stage S1 , a second stage S2 and a third stage S3 .

Specifically, in the first stage S1 of the driving method of the pixel P, the scan signal SCAN provided by the scan driving circuit 104 is at a low voltage level L, so that the switch transistors M2 and M3 are turned on and the switch transistors M4 and M5 are turned off. In this way, the power supply voltage OVDD makes the voltage level of the terminal A of the storage capacitor Cst be OVDD through the turned-on switching transistor M2, and the terminal A of the storage capacitor Cst is connected to the gate G1 of the driving transistor M1 due to the turning-on of the switching transistor M3. connected.

Then in the second stage S2, the voltage level of the scan signal SCAN provided by the scan driving circuit 104 changes to a high voltage level H that turns off the switch transistors M2 and M3, and at this time the switch transistors M4 and M5 are turned on. In this way, the terminal A of the storage capacitor Cst discharges the power supply voltage OVSS through the source-drain electrodes S1-D1 of the drive transistor M1 and the OLED 110 until the conduction current of the OLED is almost zero, at which time the organic light emitting diode The anode of the diode 110 has a voltage level V _oled (that is, the sum of the voltage across the OLED 110 and the power supply voltage OVSS), so that the voltage level at the terminal A of the storage capacitor Cst is (V _oled +V _TH ); where V _TH is the threshold voltage of the driving transistor M1. The voltage level V _oled will vary with the material decay characteristics of the OLED 210 , that is, the longer the operation time of the OLED 110 , the higher the voltage level V _oled will be. Looking back at the circuit, at this time, the data voltage Vdata provided by the data driving circuit 102 passes through the turned-on switching transistor M5 to make the voltage level of the B terminal of the storage capacitor Cst be Vdata, so that the storage capacitor Cst has a charge amount ( V _oled +V _TH -Vdata).

Then in the third stage S3, the voltage level of the scan signal SCAN provided by the scan driving circuit 104 changes to a low voltage level L that turns on the switch transistors M2 and M3, and at this time the switch transistors M4 and M5 are turned off. In this way, the driving transistor M1 can generate the pixel current I _oled according to the charge on the storage capacitor Cst (ie, the capacitor cross voltage V _s1g1 ) to drive the organic light emitting diode 110 to generate corresponding brightness. At this time, the B terminal of the storage capacitor Cst is connected to the gate G1 of the drive transistor M1 due to the conduction of the switch transistor M3, and the power supply voltage OVDD is supplied to the A terminal of the storage capacitor Cst through the conduction switch transistor M2 again so that the storage capacitor Cst The voltage level of the terminal A of the storage capacitor Cst changes to OVDD, and because of the continuous voltage across the capacitor, the voltage level of the terminal B of the storage capacitor Cst also increases by a voltage ΔV. The voltage ΔV is equal to the variation of the voltage level of terminal A from (V _oled +V _TH ) to OVDD, that is, ΔV=OVDD−V _oled −V _TH . Therefore, the voltage level of the terminal B of the storage capacitor Cst will eventually change to (Vdata+ΔV), ie (Vdata+OVDD-V _oled -V _TH ).

Based on the above, the pixel current I _oled =K*(V _s1g1 -V _TH ) ² flowing through the OLED 110, the voltage level of the gate G1 is the voltage level of the B terminal (Vdata+OVDD-V _oled -V _TH ), and the voltage level of the source S1 is the voltage level OVDD of the A terminal, so the pixel current

I _oled =K*[(OVDD-Vdata-OVDD+V _oled +V _TH )-V _TH ] ²

=K*(V _oled −Vdata) ² . So far, it can be known that in the third stage S3 (that is, the display stage), the magnitude of the pixel current I _oled flowing through the organic light emitting diode 110 is only related to the voltage level V _oled and the data voltage Vdata, but not to the threshold voltage V _TH It has nothing to do with the power supply voltage OVDD; and when the voltage level V _oled on the anode of the OLED 110 rises due to the increase of the operating time of the OLED 110, the pixel current I _oled will be increased to compensate for the decrease in the brightness of the OLED 110 . In this way, the problem of material attenuation of the organic light emitting diode and the problem of panel display unevenness caused by the influence of the power supply voltage drop (IR-drop) and the influence of the manufacturing process on the threshold voltage of the driving transistor M1 can be effectively improved, so that The active matrix organic light emitting diode display 100 can still maintain a good display quality after a long time of use.

To sum up, the embodiments of the present invention design the circuit structure of the pixel so that the magnitude of the pixel current flowing through the OLED is related to the data voltage and the voltage across the OLED, and is related to the preset voltage and the driving transistor. The critical voltage is irrelevant. Therefore, the pixel circuit, the active matrix organic light emitting diode display and the driving method of the pixel circuit proposed in the embodiments of the present invention can effectively improve the problem of panel display unevenness and the problem of material attenuation of organic light emitting diodes, so as to provide high-quality display images, And then reach the purpose of the present invention.

In addition, any person familiar with this technology can also make appropriate changes to the driving method of the active matrix light-emitting diode display and the pixel circuit proposed by the above-mentioned embodiments of the present invention, such as appropriately changing the circuit structure of the pixel circuit, the pixel of the active matrix organic light-emitting diode display, etc. The quantity, the type of each transistor (P-type or N-type), the electrical connection relationship between the source and the drain of each transistor are exchanged, and so on.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The scope of protection of the invention should be defined by the claims.

Claims (8)

1. an image element circuit is characterized in that, described image element circuit comprises:

One Organic Light Emitting Diode;

One storage capacitors comprises one first end and one second end;

One driving transistors, shinny in order to drive described Organic Light Emitting Diode, first source/drain electrode of described driving transistors is electrically coupled to described first end of described storage capacitors, and second source/drain electrode of described driving transistors is electrically coupled to described Organic Light Emitting Diode;

One first switching transistor, the grid of described first switching transistor receives the one scan signal because of the electric property coupling relation, first source/drain electrode of described first switching transistor is electrically coupled to a predeterminated voltage, and second source/drain electrode of described first switching transistor is electrically coupled to described first end of described storage capacitors;

One second switch transistor, the transistorized grid of described second switch receives described sweep signal because of the electric property coupling relation, the transistorized first source/drain electrode of described second switch is electrically coupled to described second end of described storage capacitors, and the transistorized second source/drain electrode of described second switch is electrically coupled to the grid of described driving transistors;

One the 3rd switching transistor, the grid of described the 3rd switching transistor receives described sweep signal because of the electric property coupling relation, first source/drain electrode of described the 3rd switching transistor is electrically coupled to the described second source/drain electrode of described driving transistors, and second source/drain electrode of described the 3rd switching transistor is electrically coupled to the described grid of described driving transistors; And

One the 4th switching transistor, the grid of described the 4th switching transistor receives described sweep signal because of the electric property coupling relation, first source/drain electrode of described the 4th switching transistor is electrically coupled to described second end of described storage capacitors, and second source/drain electrode of described the 4th switching transistor receives a data voltage because of the electric property coupling relation;

The conduction and cut-off opposite states of the transistorized conduction and cut-off state of described first switching transistor and described second switch and described the 3rd switching transistor and described the 4th switching transistor.

2. image element circuit as claimed in claim 1 is characterized in that, described first switching transistor and described second switch transistor are the P transistor npn npn, and described the 3rd switching transistor and described the 4th switching transistor are the N transistor npn npn.

3. an active matrix organic LED display is characterized in that, described display comprises:

One data drive circuit;

Scan driving circuit; And

At least one pixel comprises:

One Organic Light Emitting Diode;

One storage capacitors comprises one first end and one second end;

One driving transistors, shinny in order to drive described Organic Light Emitting Diode, first source/drain electrode of described driving transistors is electrically coupled to described first end of described storage capacitors, and second source/drain electrode of described driving transistors is electrically coupled to described Organic Light Emitting Diode;

One first switching transistor, the grid of described first switching transistor sees through the one scan line and is electrically coupled to described scan drive circuit, first source/drain electrode of described first switching transistor is electrically coupled to a predeterminated voltage, and second source/drain electrode of described first switching transistor is electrically coupled to described first end of described storage capacitors;

One second switch transistor, the transistorized grid of described second switch sees through described sweep trace and is electrically coupled to described scan drive circuit, the transistorized first source/drain electrode of described second switch is electrically coupled to described second end of described storage capacitors, and the transistorized second source/drain electrode of described second switch is electrically coupled to the grid of described driving transistors;

One the 3rd switching transistor, the grid of described the 3rd switching transistor sees through described sweep trace and is electrically coupled to described scan drive circuit, first source/drain electrode of described the 3rd switching transistor is electrically coupled to the described second source/drain electrode of described driving transistors, and second source/drain electrode of described the 3rd switching transistor is electrically coupled to the described grid of described driving transistors; And

One the 4th switching transistor, the grid of described the 4th switching transistor sees through described sweep trace and is electrically coupled to described scan drive circuit, first source/drain electrode of described the 4th switching transistor is electrically coupled to described second end of described storage capacitors, and second source/drain electrode of described the 4th switching transistor sees through a data line and is electrically coupled to described data drive circuit;

Wherein, the grid cut-in voltage of the transistorized grid cut-in voltage of described first switching transistor and described second switch and described the 3rd switching transistor and described the 4th switching transistor is anti-phase each other.

4. active matrix organic LED display as claimed in claim 3, it is characterized in that, described first switching transistor and described second switch transistor are the P transistor npn npn, and described the 3rd switching transistor and described the 4th switching transistor are the N transistor npn npn.

5. the driving method of an image element circuit, described image element circuit comprises an Organic Light Emitting Diode, a storage capacitors and a driving transistors, described driving transistors is shinny in order to drive described Organic Light Emitting Diode, first source/drain electrode of described driving transistors is electrically coupled to one first end of described storage capacitors, and second source/drain electrode of described driving transistors is electrically coupled to described Organic Light Emitting Diode; Described driving method comprises step:

Described first end of one predeterminated voltage to described storage capacitors is provided, and one second end of described storage capacitors is communicated with the grid of described driving transistors;

Described second end of one data voltage to described storage capacitors is provided, and described first end that makes described storage capacitors see through described driving transistors and described Organic Light Emitting Diode be discharged to the conducting electric current of described Organic Light Emitting Diode almost nil till so that described storage capacitors has a quantity of electric charge; And

Provide described predeterminated voltage to described first end of described storage capacitors and described second end of described storage capacitors is communicated with the described grid of described driving transistors again, to drive described Organic Light Emitting Diode shinny so that described driving transistors produces a pixel current according to the described quantity of electric charge of described storage capacitors;

When described pixel more comprises one first switching transistor and a second switch transistor, and first source/drain electrode of described first switching transistor is electrically coupled to described predeterminated voltage, second source/drain electrode of described first switching transistor is electrically coupled to described first end of described storage capacitors, the transistorized first source/drain electrode of described second switch is electrically coupled to described second end of described storage capacitors, when the transistorized second source/drain electrode of described second switch is electrically coupled to the described grid of described driving transistors, aforementionedly provide described predeterminated voltage, and described second end of described storage capacitors comprised with the step that the grid of described driving transistors communicates to described first end of described storage capacitors:

Described first switching transistor of conducting and described second switch transistor;

When described pixel more comprises one the 3rd switching transistor and one the 4th switching transistor, and first source/drain electrode of described the 3rd switching transistor is electrically coupled to the described second source/drain electrode of described driving transistors, second source/drain electrode of described the 3rd switching transistor is electrically coupled to the described grid of described driving transistors, first source/drain electrode of described the 4th switching transistor is electrically coupled to described second end of described storage capacitors, when second source/drain electrode of described the 4th switching transistor is electrically coupled to described data voltage, aforementioned described second end of described data voltage that provide to described storage capacitors, and described first end that makes described storage capacitors see through described driving transistors and described Organic Light Emitting Diode be discharged to the conducting electric current of described Organic Light Emitting Diode almost nil till comprise so that described storage capacitors has the step of the described quantity of electric charge:

By described first switching transistor and described second switch transistor, and described the 3rd switching transistor of conducting and described the 4th switching transistor.

6. driving method as claimed in claim 5, it is characterized in that, described first end of described predeterminated voltage to described storage capacitors is provided, and described second end of described storage capacitors more comprised with the step that the grid of described driving transistors communicates:

By described the 3rd switching transistor and described the 4th switching transistor.

7. driving method as claimed in claim 5, it is characterized in that the conduction and cut-off state of described first switching transistor, described second switch transistor, described the 3rd switching transistor and described the 4th switching transistor is determined by same control signal.

8. driving method as claimed in claim 5, it is characterized in that, provide described predeterminated voltage to described first end of described storage capacitors and described second end of described storage capacitors is communicated with the described grid of described driving transistors again, drive the shinny step of described Organic Light Emitting Diode and comprise so that described driving transistors produces described pixel current according to the described quantity of electric charge of described storage capacitors:

Described first switching transistor of conducting and described second switch transistor, and by described the 3rd switching transistor and described the 4th switching transistor.

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