CN105741778A - AMOLED display pixel current compensation circuit and driving method thereof - Google Patents

Abstract

The invention relates to the technical field of display, and more specifically, relates to an AMOLED display pixel current compensation circuit and a driving method thereof. The AMOLED display pixel current compensation circuit comprises a transistor T1, a transistor T2, a transistor T3, a transistor T4, a transistor T5, a transistor T6, a capacitor CS, and an OLED. An AMOLED pixel driving circuit provides an OLED driving current through a current compensation function. A better transistor and OLED characteristic offset compensation effect is achieved, and the linearity of input signals and output signals is improved.

Description

A kind of AMOLED shows that pixel current compensates circuit and driving method thereof

Technical field

The present invention relates to Display Technique field, show that pixel current compensates circuit and driving method thereof more particularly, to a kind of AMOLED.

Background technology

In the last few years, (ActiveMatrixOrganicLightEmittingDiode is called for short active organic LED array: AMOLED) display is with the performance of its uniqueness: high efficiency, high-contrast, high brightness, high-resolution, visible angle be big and fast response time, causes the great interest of research worker.

AMOLED shows that the simplest drive circuit of pixel is made up of two transistors and electric capacity that (being called for short " 2T-1C " circuit, as shown in Figure 1), this circuit input voltage signal in data write cycle, due to electric capacity C in data hold period_SExistence, maintenance drive transistor gate voltage is input voltage signal, thus obtain in whole drive cycle continued for constant OLED drive electric current.But, due to device preparation and aging inhomogeneities, cause that " 2T-1C " circuit exists bigger transistor TFT and OLED characteristic deviation problem, accordingly, it would be desirable to compensate circuit raising AMOLED to show pixel-driving circuit performance.

At present, many scientists and engineers are devoted to propose effective compensation drive circuit, to solve transistor TFT and OLED characteristic deviation problem.Pixel-driving circuit compensation technique is broadly divided into two kinds: voltage compensation and current compensation, wherein current compensation effect is better than voltage compensation.Li, ChesterC and Ikeda, K etc. propose the channel-length modulation phenomenon of thin film transistor (TFT) TFT in " Aphysicalpoly-siliconthinfilmtransistormodelforcircuitsi mulations [J] .IEDM'93.TechnicalDigest.; International; 1993; pp.497-500. ", but show that this phenomenon existed in pixel-driving circuit does not provide solution for AMOLED.nullNathanA and SakariyaK etc. are at " AmorphoussiliconTFTcircuitintegrationforOLEDdisplaysongl assandplastic.proceedingsoftheCustomIntegratedCircuitsCo nference,2003ProceedingsoftheIEEE2003,F21-24Sept.2003,2003 [C]. " in propose the current compensation circuit based on conventional current mirror,As shown in Figure 2,This pixel-driving circuit is based on the current compensation effect of conventional current mirror，OLED is provided to drive electric current，But its current compensation circuit is subject to channel-length modulation impact.

Therefore, in prior art, AMOLED shows that pixel-driving circuit still has following problem:

(1) the existing current compensation technology based on conventional current mirror is subject to the impact of transistor channel length mudulation effect, and compensation effect exists raising space.

(2) existing AMOLED show pixel-driving circuit data input signal and output signal be not linear relationship or the linearity relatively low, be unfavorable for that display brightness regulates.

Summary of the invention

It is an object of the invention to overcome at least one not enough of prior art, a kind of AMOLED is provided to show that pixel current compensates circuit and driving method thereof, compared with the current compensation circuit based on conventional current mirror, the modified model current compensation circuit that the present invention proposes, it may be achieved better transistor characteristic migration, OLED characteristic deviation compensate and put forward the linearity of high input signal and output signal.

For reaching above-mentioned purpose, the technical solution used in the present invention is:

A kind of AMOLED is provided to show that pixel current compensates circuit, including transistor T1, transistor T2, transistor T3, transistor T4, transistor T5, transistor T6, electric capacity C_SAnd OLED；

Wherein, the drain electrode of transistor T1 is connected with the source electrode of transistor T5；

The grid of transistor T1 is connected with the grid of transistor T2；

The drain electrode of transistor T2 is connected with the source electrode of transistor T6；

The grid of transistor T6 is connected with the grid of transistor T5；

The drain electrode of transistor T6 is connected with OLED；

The drain electrode of transistor T5 is connected with the source electrode of transistor T4；

The source electrode of transistor T4 is connected with the drain electrode of transistor T3；

The drain electrode of transistor T4 and input current signal I_DATAIt is connected；

The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SIt is connected, or the source electrode of transistor T3 is connected with the grid of transistor T5 and the grid of transistor T6 afterwards and electric capacity C_SIt is connected；

The grid of transistor T3 is connected with the grid of transistor T4；

The grid of transistor T4 and row select control signal V_SELIt is connected；

AMOLED pixel-driving circuit passes through current compensation effect, it is provided that OLED drives electric current.

In such scheme, during display data writing pattern, transistor T3 and transistor T4 conducting, AMOLED pixel-driving circuit passes through input current signal and modified model current mirror effect, it is provided that electric capacity C_SSelf-regulation driving voltage, thus obtaining OLED to drive electric current；During video data maintenance pattern, transistor T3 and transistor T4 cut-off, electric capacity C_SNot having discharge loop, maintain its self-regulation driving voltage, the driving electric current of OLED remains unchanged, and display pixel intensity is constant.The AMOLED of the present invention shows that pixel current compensates circuit, it may be achieved better transistor characteristic migration, OLED characteristic deviation compensate and put forward the linearity of high input signal and output signal.

Preferably, described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are N-type transistor；The source electrode of the source electrode of transistor T1 and transistor T2 all with power supply be connected；The grid of transistor T2 is connected with drain electrode；The positive pole of OLED and power supply V_DDBeing connected, the negative pole of OLED is connected with the drain electrode of transistor T6；The source electrode of transistor T3 is connected with the grid of transistor T5 and the grid of transistor T6 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply V_DDIt is connected.

Preferably, described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are N-type transistor；The source electrode of the source electrode of transistor T1 and transistor T2 all with power supply be connected；The grid of transistor T6 is connected with drain electrode；The positive pole of OLED and power supply V_DDBeing connected, the negative pole of OLED is connected with the drain electrode of transistor T6；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply be connected.

Preferably, described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are N-type transistor；The source electrode of the source electrode of transistor T1 and transistor T2 all with power supply be connected；The positive pole of OLED and power supply V_DDBeing connected, the negative pole of OLED is connected with the drain electrode of transistor T6；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply be connected；The grid of transistor T6 is connected with the grid of transistor T5 afterwards and power supply V_BISEIt is connected.

Preferably, described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are P-type transistor；The source electrode of transistor T1 and the source electrode of transistor T2 all with power supply V_DDIt is connected；The grid of transistor T2 is connected with drain electrode；The positive pole of OLED is connected with the drain electrode of transistor T6, and the negative pole of OLED is connected with power supply ground；The source electrode of transistor T3 is connected with the grid of transistor T5 and the grid of transistor T6 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply be connected.

Preferably, described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are P-type transistor；The source electrode of transistor T1 and the source electrode of transistor T2 all with power supply V_DDIt is connected；The grid of transistor T6 is connected with drain electrode；The positive pole of OLED is connected with the drain electrode of transistor T6, and the negative pole of OLED is connected with power supply ground；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply V_DDIt is connected.

Preferably, described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are P-type transistor；The source electrode of transistor T1 and the source electrode of transistor T2 all with power supply V_DDIt is connected；The positive pole of OLED is connected with the drain electrode of transistor T6, and the negative pole of OLED is connected with power supply ground；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply V_DDIt is connected；The grid of transistor T6 is connected with the grid of transistor T5 afterwards and power supply V_BISEIt is connected.

Preferably, the ratio of the raceway groove width of transistor T1 and the ratio of raceway groove length is wide with the raceway groove of transistor T2 and raceway groove is long ratio is fixed value, and the ratio of the ratio that ratio is wide with the raceway groove of transistor T6 and raceway groove is long of the described fixed value raceway groove width equal to transistor T5 and raceway groove length.So arrange and transistor channel length mudulation effect can be overcome to affect.

Preferably, described transistor T1 and transistor T2 is current mirror structure, and the electric current flowing through transistor T1 and transistor T2 is linear relationship.

Pixel current compensates the driving method of circuit to provide a kind of AMOLED to show, during display data writing pattern, transistor T3 and transistor T4 conducting, AMOLED pixel-driving circuit passes through input current signal and modified model current mirror effect, it is provided that electric capacity C_SSelf-regulation driving voltage, thus obtaining OLED to drive electric current；During video data maintenance pattern, transistor T3 and transistor T4 cut-off, electric capacity C_SNot having discharge loop, maintain its self-regulation driving voltage, the driving electric current of OLED remains unchanged, and display pixel intensity is constant.

Above-mentioned drive circuit and driving method are also applied for other active illuminating and show, for instance a kind of LED shows pixel-driving circuit, is that the OLED in above-mentioned AMOLED pixel-driving circuit is replaced with LED.

The present invention compared with prior art mainly has the advantages that and achieves more effective transistor characteristic migration；Achieve more effective OLED characteristic deviation to compensate；Improve input signal and the linearity of output signal.

Accompanying drawing explanation

Fig. 1 is AMOLED pixel basis drive circuit, is called for short " 2T-1C " circuit.

Fig. 2 is NathanA and SakariyaK et al. current compensation circuit proposed.

Fig. 3 (a), (b) and (c) are that the present invention propose three kinds is based on N-type transistor current compensation circuit.

Fig. 4 is the N-type transistor current compensation circuit sequential chart that the present invention proposes.

Fig. 5 (a), (b) and (c) are that the present invention propose three kinds is based on P-type transistor current compensation circuit.

Fig. 6 is the P-type transistor current compensation circuit sequential chart that the present invention proposes.

Detailed description of the invention

In order to make patent of the present invention be artisans understand that better, below in conjunction with accompanying drawing, the present invention will be further described.

Embodiment 1

The current compensation circuit of the present embodiment is based on N-type transistor, the first N-type transistor current compensation circuit, as shown in Fig. 3 (a), this drive circuit includes transistor T1, transistor T2, transistor T3, transistor T4, transistor T5, transistor T6, electric capacity C_SAnd OLED；Described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are N-type transistor；Described transistor T1 and transistor T2 is current mirror structure, and the electric current flowing through transistor T1 and transistor T2 is linear relationship；

Wherein, the drain electrode of transistor T1 is connected with the source electrode of transistor T5；

The grid of transistor T1 is connected with the grid of transistor T2；

The drain electrode of transistor T2 is connected with the source electrode of transistor T6；

The grid of transistor T6 is connected with the grid of transistor T5；

The drain electrode of transistor T6 is connected with OLED；

The drain electrode of transistor T5 is connected with the source electrode of transistor T4；

The source electrode of transistor T4 is connected with the drain electrode of transistor T3；

The drain electrode of transistor T4 and input current signal I_DATAIt is connected；

The grid of transistor T3 is connected with the grid of transistor T4；

The grid of transistor T4 and row select control signal V_SELIt is connected；

The source electrode of the source electrode of transistor T1 and transistor T2 all with power supply be connected；The grid of transistor T2 is connected with drain electrode；The positive pole of OLED and power supply V_DDBeing connected, the negative pole of OLED is connected with the drain electrode of transistor T6；The source electrode of transistor T3 is connected with the grid of transistor T5 and the grid of transistor T6 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply V_DDIt is connected.

AMOLED pixel-driving circuit passes through current compensation effect, it is provided that OLED drives electric current.

As shown in Figure 4, be the present invention propose based on N-type transistor current compensation circuit sequential chart.Driving method based on this current compensation circuit is:

During display data writing pattern, transistor T3 and transistor T4 conducting, pulsed current signal I_PULSEPurpose shortens input current signal I under small area analysis state_DATAWrite time, by transistor saturation current I_DSFormula:

$I_{DS}=\frac{{\mathrm{\μC}}_{ox}W}{2L}{(V_{GS}-V_{TH})}^2(1+{\mathrm{\λV}}_{DS})$

Wherein, W is raceway groove width, and L is that raceway groove is long；V_GSFor voltage, V between grid source electrode_THFor threshold voltage, V_DSFor voltage, C between drain-source pole_OXFor grid oxic horizon unit-area capacitance, μ is the carrier mobility in conducting channel, and λ is channel length modulation coefficient.

When preparing transistor, selecting the raceway groove width W of transistor T2 and transistor T1 and the long L ratio of raceway groove is B, it may be assumed that

$\frac{W_{T1}}{L_{T1}}:\frac{W_{T2}}{L_{T2}}=1:B$

The source electrode of transistor T1 and grid connect with the source electrode of transistor T2 and grid respectively, i.e. voltage V between the grid source electrode of transistor T1 and transistor T2_GSEqual, the threshold voltage V of transistor T1 and transistor T2_THEqual, so under same technique, transistor T1 drain current and transistor T2 drain current ratio can abbreviation be:

$\frac{I_{DS\_T1}}{I_{DS\_T2}}=\frac{(1+{\mathrm{\λV}}_{DS\_T1})}{(1+{\mathrm{\λV}}_{DS\_T2})}\·\frac{1}{B}$

Wherein, λ is channel length modulation coefficient, I_{DS_T1}For transistor T1 drain-source current, I_{DS_T2}For transistor T2 drain-source current, V_{DS_T1}For transistor T1 drain-source voltage, V_{DS_T2}For transistor T2 drain-source voltage.

From above formula it can be seen that work as V_{DS_T1}And V_{DS_T2}Equal guarantee transistor T2 drain current and transistor T1 drain current ratio are B.Add transistor T5 and transistor T6 for this circuit, when selecting transistor T5 and transistor T6 parameter, make:

$\frac{W_{T5}}{L_{T5}}:\frac{W_{T6}}{L_{T6}}=1:B$

Due to current relationship in the circuit loop at transistor T5 and transistor T6 place, i.e. voltage V between the grid source electrode of transistor T5 and transistor T6_GSNeeding equal, the grid of transistor T5 and transistor T6 is connected, and transistor T5 source electrode connects transistor T1 drain electrode, and transistor T6 source electrode connects transistor T2 drain electrode, so obtaining:

V_{DS_T1}=V_{DS_T2}

I_{DS_T2}=B I_{DS_T1}

From circuit loop relation:

I_OLED=B I_DATA

It is hereby understood that OLED current I_OLEDWith data input current I_DATAIt is linear relationship, and is not affected by transistor channel length mudulation effect.

More than analyze process it can be seen that the drive circuit based on modified model current mirror is more accurate compared to the current mirror relation of the drive circuit (Fig. 2) based on conventional current mirror, overcome the impact of transistor channel length mudulation effect.Output current signal I_OLEDWith input current I_DATABetween there is linear relationship, and the parameter of device is unrelated, so the current compensation circuit that the present invention proposes can realize better transistor and OLED characteristic deviation compensation effect, puies forward the linearity of high input signal and output signal.

Another of this drive circuit explain be pixel-driving circuit can as a kind of constant-current source structure, based on the output resistance R of the current compensation circuit of conventional current mirror (Fig. 2)_OUT1For:

R_OUT1=r_ds2

Wherein, r_ds2For transistor T2 drain-source resistance.

Output resistance R based on the current compensation circuit of modified model current mirror_OUT2For:

R_OUT2=r_ds2·r_ds6·g_m6

Wherein, r_ds2For transistor T2 drain-source resistance, r_ds6For transistor T6 drain-source resistance, g_m6Mutual conductance for transistor T6.

The output resistance of constant-current source becomes big Ability of Resisting Disturbance and strengthens, so comparing the current compensation electricity based on conventional current mirror based on the current compensation circuit of modified model current mirror can realize better transistor and OLED characteristic deviation compensation effect, put forward the linearity of high input signal and output signal.

During video data maintenance pattern, transistor T3 and transistor T4 cut-off, electric capacity C_SThere is no discharge loop, maintain its self-regulation driving voltage, the driving electric current I of OLED_OLEDRemaining unchanged, display pixel intensity is constant.

Circuit and driving method principle thereof is compensated from above-mentioned display pixel current:

(1) the mirror image ratio B of current mirror is fixed value, the driving electric current I of OLED_OLEDIt is limited only by data input current I_DATAImpact, OLED is driven electric current I by transistor characteristic skew (threshold voltage and carrier mobility)_OLEDThis drive circuit affect less, so can compensate for transistor characteristic skew.

(2) the mirror image ratio B of current mirror is fixed value, the driving electric current I of OLED_OLEDIt is limited only by data input current I_DATAImpact, OLED is driven electric current I by OLED characteristic deviation_OLEDThis drive circuit affect less, so can compensate for OLED characteristic deviation.

(3) AMOLED shows the output electric current I of pixel-driving circuit_OLEDWith data input current I_DATALinear, the linearity is B, so input signal is better with the linearity of output signal.

Driving method based on this current compensation circuit is: during display data writing pattern, and transistor T3 and transistor T4 conducting, AMOLED pixel-driving circuit passes through input current signal and modified model current mirror effect, it is provided that electric capacity C_SSelf-regulation driving voltage, thus obtaining OLED to drive electric current；During video data maintenance pattern, transistor T3 and transistor T4 cut-off, electric capacity C_SNot having discharge loop, maintain its self-regulation driving voltage, the driving electric current of OLED remains unchanged, and display pixel intensity is constant.

As shown in Fig. 3 (b), being the second N-type transistor current compensation circuit of proposing of the present invention, concrete current compensation circuit is:

The drain electrode of transistor T1 is connected with the source electrode of transistor T5；

The grid of transistor T1 is connected with the grid of transistor T2；

The drain electrode of transistor T2 is connected with the source electrode of transistor T6；

The grid of transistor T6 is connected with the grid of transistor T5；

The drain electrode of transistor T6 is connected with OLED；

The drain electrode of transistor T5 is connected with the source electrode of transistor T4；

The source electrode of transistor T4 is connected with the drain electrode of transistor T3；

The drain electrode of transistor T4 and input current signal I_DATAIt is connected；

The grid of transistor T3 is connected with the grid of transistor T4；

The grid of transistor T4 and row select control signal V_SELIt is connected；

The source electrode of the source electrode of transistor T1 and transistor T2 all with power supply be connected；The grid of transistor T6 is connected with drain electrode；The positive pole of OLED and power supply V_DDBeing connected, the negative pole of OLED is connected with the drain electrode of transistor T6；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply be connected.

The sequential chart of this circuit is as shown in Figure 4, identical based on the driving principle of this current compensation circuit and method and Fig. 3 (a).

As shown in Fig. 3 (c), being the third N-type transistor current compensation circuit of proposing of the present invention, concrete current compensation circuit is:

The drain electrode of transistor T1 is connected with the source electrode of transistor T5；

The grid of transistor T1 is connected with the grid of transistor T2；

The drain electrode of transistor T2 is connected with the source electrode of transistor T6；

The grid of transistor T6 is connected with the grid of transistor T5；

The drain electrode of transistor T6 is connected with OLED；

The drain electrode of transistor T5 is connected with the source electrode of transistor T4；

The source electrode of transistor T4 is connected with the drain electrode of transistor T3；

The drain electrode of transistor T4 and input current signal I_DATAIt is connected；

The grid of transistor T3 is connected with the grid of transistor T4；

The grid of transistor T4 and row select control signal V_SELIt is connected；

The source electrode of the source electrode of transistor T1 and transistor T2 all with power supply be connected；The positive pole of OLED and power supply V_DDBeing connected, the negative pole of OLED is connected with the drain electrode of transistor T6；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply be connected；The grid of transistor T6 is connected with the grid of transistor T5 afterwards and power supply V_BISEIt is connected.

Wherein, power supply V_BISEBias voltage is provided for transistor T5 and transistor T6.

The sequential chart of this circuit is as shown in Figure 4, identical based on the driving principle of this current compensation circuit and method and Fig. 3 (a).

Embodiment 2

The current compensation circuit of the present embodiment is based on P-type transistor, the first P-type transistor current compensation circuit, and as shown in Fig. 5 (a), concrete current compensation circuit is:

The drain electrode of transistor T1 is connected with the source electrode of transistor T5；

The grid of transistor T1 is connected with the grid of transistor T2；

The drain electrode of transistor T2 is connected with the source electrode of transistor T6；

The grid of transistor T6 is connected with the grid of transistor T5；

The drain electrode of transistor T6 is connected with OLED；

The drain electrode of transistor T5 is connected with the source electrode of transistor T4；

The source electrode of transistor T4 is connected with the drain electrode of transistor T3；

The drain electrode of transistor T4 and input current signal I_DATAIt is connected；

The grid of transistor T3 is connected with the grid of transistor T4；

The grid of transistor T4 and row select control signal V_SELIt is connected；

The source electrode of transistor T1 and the source electrode of transistor T2 all with power supply V_DDIt is connected；The grid of transistor T2 is connected with drain electrode；The positive pole of OLED is connected with the drain electrode of transistor T6, and the negative pole of OLED is connected with power supply ground；The source electrode of transistor T3 is connected with the grid of transistor T5 and the grid of transistor T6 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply be connected.

The sequential chart of this circuit is as shown in Figure 6, identical based on the driving principle of this current compensation circuit and method and embodiment one.

As shown in Fig. 5 (b), for the second P-type transistor current compensation circuit, concrete current compensation circuit is:

The drain electrode of transistor T1 is connected with the source electrode of transistor T5；

The grid of transistor T1 is connected with the grid of transistor T2；

The drain electrode of transistor T2 is connected with the source electrode of transistor T6；

The grid of transistor T6 is connected with the grid of transistor T5；

The drain electrode of transistor T6 is connected with OLED；

The drain electrode of transistor T5 is connected with the source electrode of transistor T4；

The source electrode of transistor T4 is connected with the drain electrode of transistor T3；

The drain electrode of transistor T4 and input current signal I_DATAIt is connected；

The grid of transistor T3 is connected with the grid of transistor T4；

The grid of transistor T4 and row select control signal V_SELIt is connected；

The source electrode of transistor T1 and the source electrode of transistor T2 all with power supply V_DDIt is connected；The grid of transistor T6 is connected with drain electrode；The positive pole of OLED is connected with the drain electrode of transistor T6, and the negative pole of OLED is connected with power supply ground；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply V_DDIt is connected.

The sequential chart of this circuit is as shown in Figure 6, identical based on the driving principle of this current compensation circuit and method and embodiment one.

As shown in Fig. 5 (c), being the third P-type transistor current compensation circuit of proposing of the present invention, concrete current compensation circuit is:

The drain electrode of transistor T1 is connected with the source electrode of transistor T5；

The grid of transistor T1 is connected with the grid of transistor T2；

The drain electrode of transistor T2 is connected with the source electrode of transistor T6；

The grid of transistor T6 is connected with the grid of transistor T5；

The drain electrode of transistor T6 is connected with OLED；

The drain electrode of transistor T5 is connected with the source electrode of transistor T4；

The source electrode of transistor T4 is connected with the drain electrode of transistor T3；

The drain electrode of transistor T4 and input current signal I_DATAIt is connected；

The grid of transistor T3 is connected with the grid of transistor T4；

The grid of transistor T4 and row select control signal V_SELIt is connected；

The source electrode of transistor T1 and the source electrode of transistor T2 all with power supply V_DDIt is connected；The positive pole of OLED is connected with the drain electrode of transistor T6, and the negative pole of OLED is connected with power supply ground；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply V_DDIt is connected；The grid of transistor T6 is connected with the grid of transistor T5 afterwards and power supply V_BISEIt is connected.

Wherein, power supply V_BISEBias voltage is provided for transistor T5 and transistor T6.

The sequential chart of this circuit is as shown in Figure 6, identical based on the driving principle of this current compensation circuit and method and embodiment one.

Embodiments of the present invention by the change made under restriction described above, other any spirit without departing from the present invention and principle, modification, replacement, combination, simplification, all not should be the substitute mode of equivalence, are included within protection scope of the present invention.

Claims (10)

1. an AMOLED shows that pixel current compensates circuit, it is characterised in that this drive circuit includes transistor T1, transistor T2, transistor T3, transistor T4, transistor T5, transistor T6, electric capacity C_SAnd OLED；

Wherein, the drain electrode of transistor T1 is connected with the source electrode of transistor T5；

The grid of transistor T1 is connected with the grid of transistor T2；

The drain electrode of transistor T2 is connected with the source electrode of transistor T6；

The grid of transistor T6 is connected with the grid of transistor T5；

The drain electrode of transistor T6 is connected with OLED；

The drain electrode of transistor T5 is connected with the source electrode of transistor T4；

The source electrode of transistor T4 is connected with the drain electrode of transistor T3；

The drain electrode of transistor T4 and input current signal I_DATAIt is connected；

The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SIt is connected, or the source electrode of transistor T3 is connected with the grid of transistor T5 and the grid of transistor T6 afterwards and electric capacity C_SIt is connected；

The grid of transistor T3 is connected with the grid of transistor T4；

The grid of transistor T4 and row select control signal V_SELIt is connected.

2. AMOLED according to claim 1 shows that pixel current compensates circuit, it is characterised in that described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are N-type transistor；The source electrode of the source electrode of transistor T1 and transistor T2 all with power supply be connected；The grid of transistor T2 is connected with drain electrode；The positive pole of OLED and power supply V_DDBeing connected, the negative pole of OLED is connected with the drain electrode of transistor T6；The source electrode of transistor T3 is connected with the grid of transistor T5 and the grid of transistor T6 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply V_DDIt is connected.

3. AMOLED according to claim 1 shows that pixel current compensates circuit, it is characterised in that described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are N-type transistor；The source electrode of the source electrode of transistor T1 and transistor T2 all with power supply be connected；The grid of transistor T6 is connected with drain electrode；The positive pole of OLED and power supply V_DDBeing connected, the negative pole of OLED is connected with the drain electrode of transistor T6；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply be connected.

4. AMOLED according to claim 1 shows that pixel current compensates circuit, it is characterised in that described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are N-type transistor；The source electrode of the source electrode of transistor T1 and transistor T2 all with power supply be connected；The positive pole of OLED and power supply V_DDBeing connected, the negative pole of OLED is connected with the drain electrode of transistor T6；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply be connected；The grid of transistor T6 is connected with the grid of transistor T5 afterwards and power supply V_BISEIt is connected.

5. AMOLED according to claim 1 shows that pixel current compensates circuit, it is characterised in that described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are P-type transistor；The source electrode of transistor T1 and the source electrode of transistor T2 all with power supply V_DDIt is connected；The grid of transistor T2 is connected with drain electrode；The positive pole of OLED is connected with the drain electrode of transistor T6, and the negative pole of OLED is connected with power supply ground；The source electrode of transistor T3 is connected with the grid of transistor T5 and the grid of transistor T6 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply be connected.

6. AMOLED according to claim 1 shows that pixel current compensates circuit, it is characterised in that described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are P-type transistor；The source electrode of transistor T1 and the source electrode of transistor T2 all with power supply V_DDIt is connected；The grid of transistor T6 is connected with drain electrode；The positive pole of OLED is connected with the drain electrode of transistor T6, and the negative pole of OLED is connected with power supply ground；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply V_DDIt is connected.

7. AMOLED according to claim 1 shows that pixel current compensates circuit, it is characterised in that described transistor T1, transistor T2, transistor T3, transistor T4, transistor T5 and transistor T6 are P-type transistor；The source electrode of transistor T1 and the source electrode of transistor T2 all with power supply V_DDIt is connected；The positive pole of OLED is connected with the drain electrode of transistor T6, and the negative pole of OLED is connected with power supply ground；The source electrode of transistor T3 is connected with the grid of transistor T1 and the grid of transistor T2 afterwards and electric capacity C_SOne end be connected, electric capacity C_SThe other end and power supply V_DDIt is connected；The grid of transistor T6 is connected with the grid of transistor T5 afterwards and power supply V_BISEIt is connected.

8. AMOLED according to claim 1 shows that pixel current compensates circuit, it is characterized in that, the ratio of the raceway groove width of transistor T1 and the ratio of raceway groove length is wide with the raceway groove of transistor T2 and raceway groove is long ratio is fixed value, and the ratio of the ratio that ratio is wide with the raceway groove of transistor T6 and raceway groove is long of the described fixed value raceway groove width equal to transistor T5 and raceway groove length.

9. the AMOLED according to any one of claim 1 to 8 shows that pixel current compensates circuit, it is characterised in that described transistor T1 and transistor T2 is current mirror structure, and the electric current flowing through transistor T1 and transistor T2 is linear relationship.

10. AMOLED shows that pixel current compensates a driving method for circuit, and this driving method uses the AMOLED described in claim 9 to show pixel current compensation circuit, it is characterised in that:

During display data writing pattern, transistor T3 and transistor T4 conducting, AMOLED pixel-driving circuit is by the effect of input current signal and modified model current mirror, it is provided that electric capacity C_SSelf-regulation driving voltage, thus obtaining OLED to drive electric current；

During video data maintenance pattern, transistor T3 and transistor T4 cut-off, electric capacity C_SNot having discharge loop, maintain its self-regulation driving voltage, the driving electric current of OLED remains unchanged, and display pixel intensity is constant.