CN105960670A - Charge-based compensation and parameter extraction in AMOLED displays - Google Patents

Abstract

A system reads a desired circuit parameter from a pixel circuit that includes a light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input, and a storage device to store a programming signal. One embodiment of the extraction system turns off the drive device and supplies a predetermined voltage from an external source to the light emitting device, discharges the light emitting device until the light emitting device turns off, and then reads the voltage on the light emitting device while that device is turned off. The voltages on the light emitting devices in a plurality of pixel circuits may be read via the same external line, at different times. In- pixel, charge-based compensation schemes are also discussed, which can be used with the external parameter extraction implementations.

Description

Compensation based on electric charge in displayer and parameter extraction

Technical field

The present invention relates generally to active matrix organic light-emitting device (AMOLED) display, and this kind of more particularly to extracting Image element circuit in display and the parameter of light-emitting device.

Background technology

Relative to conventional LCD device, the advantage of active matrix organic light-emitting device (" AMOLED ") display includes relatively Low power consumption, manufacture flexibly and faster refresh rate.Compared with conventional LCD device, do not have in displayer Have a backlight, and thus each pixel be made up of the OLED of independent luminous different colours.OLED is based on by by program voltage control The electric current driving transistor supply of system comes luminous.The power consumed in each pixel has with the size of the light of generation in this pixel Relation.

Output quality transistor driven in pixel based on OLED and the performance impact of OLED itself, wherein drive crystalline substance Body pipe is generally made up of the material including but not limited to non-crystalline silicon, polysilicon or metal-oxide.Specifically, transistor is driven Threshold voltage and mobility tend to pixel ageing and change.In order to keep picture quality, it is necessary to programmed by adjustment The change of these parameters is compensated by voltage.For that purpose it is necessary to extract this kind of parameter from drive circuit.Simple for extracting The assembly of this kind of parameter in drive circuit increase the greater room needed on the display base plate of drive circuit, and Therefore aperture or region that light is launched are reduced from OLED.

When being biased in saturation, the I-V characteristic of thin film drive transistor depends on as manufacturing crystal The mobility of the function of the material of pipe and threshold voltage.Therefore, the different film transistor devices on display pannel are applied May present non-homogeneous due to the processing differences (process variation) of aging and mobility and threshold voltage Sexual behaviour.Therefore, for constant voltage, each device may have different drain currents.Extreme example is probably, and one Individual device is likely to be of low valve valve and low mobility compared with second device with high threshold value and high mobility.

Therefore, in the case of using considerably less electronic building brick to keep expectation aperture, to driving, TFT's and OLED is non- Uniformity parameters (that is, threshold voltage V_thAnd mobility [mu]) extraction become challenging.It is desirable that, use the fewest Assembly extract this kind of parameter in the drive circuit of OLED pixel so that pixel aperture maximize.It is also expected to It is to combine so that life performance optimization by compensating (in-pixel compensation) in parameter extraction and pixel. Compensate in pixel refer to the most externally in the case of image element circuit extracts any information to aging within image element circuit or The compensation that time-dependent parameter is carried out.

Summary of the invention

Embodiment disclosed by the invention reads from image element circuit or extracts desired circuit parameter, and described image element circuit includes Light-emitting device, for the driving means that programmable driving electric current is provided to described light-emitting device, programming input and use Storage device in storage programming signal.Described extracting method includes: make described driving means end, from external source by predetermined Voltage supply, to described light-emitting device, makes the electric discharge of described light-emitting device until described light-emitting device ends, and subsequently at described The voltage on described light-emitting device is read when electro-optical device is cut off.In one embodiment, in the different time via identical Outer lines reads the described voltage of each described light-emitting device in multiple image element circuits.Can affect in the following way institute Expect the reading of parameter: described image element circuit is connected to charge-pump amplifier；Make described charge-pump amplifier and described pixel Circuit isolation is to provide voltage that is proportional to charge level or that be integrated the electric current from described image element circuit output；Read Take the described voltage output of described charge-pump amplifier；And determine at least from the described voltage output of described charge-pump amplifier One image element circuit parameter.

Another embodiment extracts circuit parameter from image element circuit in the following way: described driving means turned on so that The voltage of described light-emitting device rises above the level of its conducting voltage；Described driving means is made to end so that described Voltage on electro-optical device is discharged by described light-emitting device until described light-emitting device ends；And subsequently at described device quilt The voltage on described light-emitting device is read during cut-off.

Another embodiment extracts circuit parameter from image element circuit in the following way: be programmed described image element circuit； Described driving means is made to turn on；And flow through described by (i) reading when predetermined voltage is applied to described driving means The electric current of driving means or (ii) read the voltage in described driving means when making predetermined electric current flow through described driving means Extract the parameter of described driving means.

Another embodiment extracts circuit parameter from image element circuit in the following way: make described driving means turn on, and Change the voltage between the grid of described driving transistor and source electrode or drain electrode so that described driving transistor is between the very first time When period operates in linear zone and operates in saturation region during the second time interval, measure described driving transistor Electric current and voltage；And according to being used in said two district described electric current and the voltage that the described driving transistor operated is measured Relation extract described light-emitting device parameter.

Show and describe many other embodiments in this article.

In view of the various embodiments carried out with reference to accompanying drawing and/or the detailed description of each side, the present invention's is above-mentioned and another Outer each side and each embodiment will be apparent to those skilled in the art.Next the brief of accompanying drawing is provided to say Bright.

Accompanying drawing explanation

Reading detailed description below and with reference to after accompanying drawing, the foregoing and other advantages of the present invention will become to show and It is clear to.

Fig. 1 is the block diagram having and compensating the displayer controlled；

Fig. 2 is the circuit diagram of the data extraction circuit of the double transistor pixels in the displayer in Fig. 1；

Fig. 3 A is that the data delivering to threshold voltage and mobility for extracting N-shaped driving transistor in Fig. 2 extract electricity The signal timing diagram of the signal on road；

Fig. 3 B is the data delivering to the characteristic voltage for extracting OLED in Fig. 2 in the case of N-shaped drives transistor Extract the signal timing diagram of the signal of circuit；

Fig. 3 C is the number delivering to the threshold voltage for extracting N-shaped driving transistor in the way of directly reading in Fig. 2 Signal timing diagram according to the signal extracting circuit；

Fig. 4 A is that the data delivering to threshold voltage and mobility for extracting p-type driving transistor in Fig. 2 extract electricity The signal timing diagram of the signal on road；

Fig. 4 B is the data delivering to the characteristic voltage for extracting OLED in Fig. 2 in the case of p-type drives transistor Extract the signal timing diagram of the signal of circuit；

Fig. 4 C is the number delivering to the threshold voltage for extracting p-type driving transistor in the way of directly reading in Fig. 2 Signal timing diagram according to the signal extracting circuit；

Fig. 4 D be deliver in Fig. 2 for by using N-shaped or p-type to drive transistor directly to read OLED conducting voltage The signal timing diagram of signal of data extraction circuit；

Fig. 5 is the data of the extracting parameter of three transistor driver circuits of the pixel of the displayer in Fig. 1 Extract the circuit diagram of circuit；

Fig. 6 A is to deliver to threshold voltage and the data extraction circuit of mobility for extracting driving transistor in Fig. 5 The signal timing diagram of signal；

Fig. 6 B is the signal sequence of the signal of the data extraction circuit delivering to the characteristic voltage for extracting OLED in Fig. 5 Figure；

Fig. 6 C is that the data delivering to the threshold voltage for extracting driving transistor in the way of directly reading in Fig. 5 carry The signal timing diagram of the signal of sense circuit；

Fig. 6 D delivers to the data extraction circuit of the characteristic voltage for extracting OLED in the way of directly reading in Fig. 5 The signal timing diagram of signal；

Fig. 7 is the extraction week of the characteristic driving transistor and OLED for reading the image element circuit in displayer The flow chart of phase；

Fig. 8 is different parameter extraction cycles and the flow chart of final application；And

Fig. 9 is block diagram and the flow chart of the assembly of data extraction system.

Figure 10 is the threshold voltage driving transistor in the revision for extracting the circuit in Fig. 5 and mobility The signal timing diagram of signal of data extraction circuit；

Figure 11 delivers to the data extraction circuit of the characteristic voltage of the OLED in the revision for extracting the circuit in Fig. 5 The signal timing diagram of signal；

Figure 12 is that the data of the drive circuit read pixel electric charge for the pixel from the displayer of Fig. 1 are extracted The circuit diagram of circuit；

Figure 13 is to deliver to for by externally initializing the data extraction circuit that node carrys out Figure 12 of read pixel state The signal timing diagram of signal；

Figure 14 is for by externally initializing the flow chart of pixel status that node reads the circuit of Figure 12；

Figure 15 is to deliver to for by internally initializing the data extraction circuit that node carrys out Figure 12 of read pixel state The signal timing diagram of signal；

Figure 16 is the flow chart for reading the pixel status in the circuit of Figure 12 by internally initializing node；

Figure 17 is that the use of two different pixels read pixel electric charges in the displayer from Fig. 1 is public The circuit diagram of a pair circuit as the circuit of Figure 12 of monitoring line；

Figure 18 is the signal of the data extraction circuit sent when shared monitoring line to the Figure 17 for read pixel electric charge Signal timing diagram；And

Figure 19 is the pixel status for reading a pair circuit using common monitoring line as the circuit of Figure 17 Flow chart.

Figure 20 A is the schematic circuit diagram improving image element circuit.

Figure 20 B be a diagram that the sequential chart of the operation of the image element circuit using compensation based on electric charge of Figure 20 A.

Figure 21 be a diagram that the operation of the readout for obtaining the parameter driving transistor of the image element circuit of Figure 20 A Sequential chart.

Figure 22 be a diagram that the sequential of the operation of the readout of the parameter for obtaining OLED of the image element circuit of Figure 20 A Figure.

Figure 23 be a diagram that the improvement operation of the readout of the parameter for obtaining OLED of the image element circuit of Figure 20 A Sequential chart.

Figure 24 is the circuit for extracting parasitic capacitance from the image element circuit using external compensation.

Figure 25 illustrates the image element circuit that can be used for current measurement.

Figure 26 is exemplary pixel circuits and its correlation timing figure using in pixel based on electric charge and compensating realization.

Figure 27 shows identical from the image element circuit shown in Figure 26 but uses the image element circuit of different temporal order.

Figure 28 be EM signal be divided into two signals be used in the image element circuit of compensation internal node reset another The example of image element circuit.

Figure 29 is can to read OLED current or another example of the image element circuit of voltage and sequential chart via monitoring line.

Figure 30 is to driving transistor to change or the aging compensation pixel circuit based on electric charge compensated and at that time Another example of sequence figure.

Figure 31 is image element circuit and the correlation timing figure with the discharge cycle making storage capacitor discharge at least in part Another example.

Figure 32 with Figure 31 is similar, in addition to acting on as switch except driving transistor T1 to be programmed to.

Figure 33 is to read OLED via monitoring line (it can also serve as the reference line for programming information and/or data wire) Voltage or the image element circuit of electric current and correlation timing figure thereof.

Figure 34 be a diagram that another image element circuit and the correlation timing figure of the other method realizing EM function.

Figure 35 is conventional image element circuit.

Figure 36 is the image element circuit that one or more switch can be shared between the row of pel array and/or row.

Figure 37 shows that the image element circuit from Figure 36 is similar but uses the image element circuit of different programming operations.

Figure 38 illustrates another image element circuit of shared one or more switch.

Figure 39 A and 39B illustrates image element circuit and the correlation timing figure with discharge cycle.

Figure 40 A and 40B illustrates another image element circuit and the correlation timing figure with the reset cycle.

Figure 41 A and 41B illustrates has the reset another image element circuit with readout interval and correlation timing figure.

Figure 42 A and 42B illustrates has the reset another image element circuit with readout interval and correlation timing figure.

Figure 43 A and 43B illustrates another image element circuit and the correlation timing figure with the readout interval after programming cycle.

Figure 44 A and 44B illustrates to be had after the programming cycle using cut-off current to be programmed image element circuit Another image element circuit of readout interval and correlation timing figure.

Figure 45 A and 45B illustrates another image element circuit and the correlation timing figure with discharge cycle.

Figure 46 A and 46B illustrates another image element circuit and the correlation timing figure with the reset cycle.

Figure 47 A and 47B illustrates has the reset another image element circuit with readout interval and correlation timing figure.

Figure 48 A and 48B illustrates has the reset another image element circuit with readout interval and correlation timing figure.

Figure 49 A and 49B illustrates another image element circuit and the correlation timing of the readout interval having after programming cycle Figure.

Although the present invention easily carries out various amendment and alternative form, but is illustrated by way of example in the accompanying drawings Specific embodiment and will describe in detail in this manual.It is to be appreciated, however, that the present invention is not intended to be limited to disclosed Specific form.On the contrary, the present invention covers and falls into as defined by the appended claims in the spirit and scope of the present invention All modifications, equivalent and replacement scheme.

Detailed description of the invention

Fig. 1 is the electronic display system 100 with active matrix area or pel array 102, at this pel array 102 In, the pixelated array 104 of n × m is arranged with the structure of row and column.Example for convenience, illustrate only two row and two row.? The outside of the active matrix area of pel array 102 is outer peripheral areas 106, is wherein disposed with for driving and controlling pel array The peripheral circuit of 102.Peripheral circuit includes address or gate driver circuit 108, data or source driver circuit 110, control Device 112 processed and optional supply voltage (such as, Vdd) driver 114.Controller 112 control gate driver 108, source drive Device 110 and supply voltage driver 114.Gate drivers 108 under the control of controller 112 to address wire or select line SEL [i] and SEL [i+1] etc. operate, a described address wire or select line corresponding to the pixel in pel array 102 or Every a line in image element circuit 104.In following pixel shares structure, grid or address driver circuits 108 can also Selectively to the overall situation select line GSEL [j] and the most right/GSEL [j] operate, the overall situation select line GSEL [j] or/ Multiple row (every two row of such as pixel 104) in pixel 104 in pel array 102 are operated by GSEL [j].Source electrode drives Voltage data line Vdata [k] and Vdata [k+1] etc. are operated under the control of controller 112 by dynamic device circuit 110, and one Bar voltage data line is corresponding to the every string in the pixel 104 in pel array 102.Each pixel 104 given by voltage data line Transport the voltage-programming information of the brightness of each light-emitting device represented in pixel 104.Such as electric capacity in each pixel 104 The memory elements such as device store described voltage-programming information until luminescence or drive cycle make light-emitting device turn on.Optional supply voltage Driver 114 controls supply voltage (EL_Vdd) line under the control of controller 112, and a power voltage line is corresponding to pixel The each row or column in pixel 104 in array 102.

Display system 100 also include from DOL Data Output Line VD [k] and VD [k+1] etc. read output data electric current supply and Reading circuit 120, a data output lead is corresponding to the every string in the pixel 104 in pel array 102.

As it is known, each pixel or image element circuit 104 in display system 100 need to use and represent in pixel 104 The information (curtage or the form of electric charge) of the brightness of light-emitting device is programmed.Frame defines and includes (i) programming week Phase or stage and (ii) drive or light period or the time period in stage, in programming cycle or use during the stage and represent brightness Program voltage each pixel in display system 100 is programmed, and driving or light period or during the stage Each light-emitting device in each pixel is switched on thus sends out with the brightness matched with the program voltage being stored in memory element Light.Therefore, frame is in display system 100 in many still images of the complete moving image of display of composition.Extremely Few two schemes existed for programming and drive pixel: line by line or frame by frame.In programming line by line, compiled in next line pixel Before journey and driving, one-row pixels is programmed and is driven subsequently.In programming frame by frame, the first institute in display system 100 There is capable pixel to be all programmed, and drive the pixel of all row immediately.Any one scheme can be at the beginning of every frame or knot Using of short duration vertical blanking time at bundle, in this vertical blanking time, pixel is the most unprogrammed is not the most driven.

It is positioned at the assembly outside pel array 102 and can be arranged the same thing being disposed with pel array 102 thereon In the outer peripheral areas 106 around pel array 102 on reason substrate.These assemblies include gate drivers 108, source electrode driver 110, optional supply voltage driver 114 and electric current supply and reading circuit 120.Alternately, in outer peripheral areas 106 A little assemblies can be disposed on the substrate identical from pel array 102 that other assembly is disposed on different substrates, or All component in person's outer peripheral areas can be disposed on the substrate different from the substrate being disposed with pel array 102 on it. Gate drivers 108, source electrode driver 110 constitute display driving circuit together with supply voltage driver 114.Some structure In display driving circuit can include gate drivers 108 and source electrode driver 110 but do not include supply voltage control 114.

When being biased in saturation, metal-oxide semiconductor (MOS) (MOS) transistor (is concerned with thin in the case of this Film transistor) single order I-V characteristic be modeled as:

$I_D=\frac{1}{2}{\mathrm{\μC}}_{ox}\frac{W}{L}{(V_{GS}-V_{th})}^2$

Here, I_DIt is drain current and V_GSThe voltage difference being consequently exerted between the gate terminal of transistor and source terminal. Apply the film transistor device in display system 100 due to aging and mobility (μ) and threshold voltage (V_th) processing poor Different and present heterogeneity behavior.Therefore, for constant voltage difference V being applied between grid and source electrode_GS, picture element matrix Each transistor on 102 is likely to be of different drain currents based on uncertain mobility and threshold voltage:

I_D(i,j)=f (μ_i,j,V_thi,j)

Here, i and j be pixel coordinate in the n × m array of the pixel of the pel array 102 etc. of such as Fig. 1 (row and Row).

Fig. 2 shows the data extraction system 200 including pair transistor (2T) drive circuit 202 and reading circuit 204. In the display system with 2T image element circuit 104, it is selectable that supply voltage controls 114.Reading circuit 204 is that electric current supplies Data should be collected with a part for reading circuit 120 and from string pixel 104 as shown in Figure 1.Reading circuit 204 includes electric charge Pump circuit 206 and box switch circuits 208.Supply voltage is provided to drive circuit by voltage source 210 by box switch circuits 208 202.Charge pump circuit 206 and box switch circuits 208 are used in the top side of array 102 or bottom side (the most in FIG Voltage drive 114 and electric current supply and reading circuit 120 in).This is straight by the substrate identical with pel array 102 Connect and manufacture or by microchip is bonded on substrate or realizing as the flex of hybrid solution.

Drive circuit 202 includes driving transistor 220, organic luminescent device 222, drain electrode storage capacitor 224, source electrode Storage capacitor 226 and selection transistor 228.Supply lines 212 provides to such as drive circuit 202 grade one column driver circuit Supply voltage and supervised path (for reading circuit 204).Line input 230 is selected to be connected to select the grid of transistor 228 Pole.Programming data input 232 is connected to drive the grid of transistor 220 by selecting transistor 228.Drive transistor 220 Drain electrode be connected to power voltage line 212 and drive transistor 220 source electrode be connected to OLED 222.Transistor 228 is selected to control System programming input 230 is to the connection of the grid driving transistor 220.Source electrode storage capacitor 226 is connected to drive transistor Between grid and the source electrode of 220.Drain electrode storage capacitor 224 is connected to drive between the grid of transistor 220 and drain electrode.OLED 222 have the parasitic capacitance being modeled as capacitor 240.Power voltage line 212 has equally and is modeled as posting of capacitor 242 Raw electric capacity.The thin film transistor (TFT) that driving transistor 220 in this example is made up of non-crystalline silicon.It is of course also possible to use such as Other material such as polysilicon or metal-oxide.Node 244 is that the source electrode driving transistor 220 is connected with the anode of OLED 222 Circuit node together.In this example, driving transistor 220 is n-type transistor.As explained belowly, it is possible to use p Type drives transistor to replace N-shaped to drive transistor 220 to realize system 200.

Reading circuit 204 includes charge pump circuit 206 and box switch circuits 208.Charge pump circuit 206 includes having positive and negative The amplifier 250 of input.The negative input end of amplifier 250 is connected to capacitor 252 (C_int), capacitor 252C_intTo putting In parallel with switch 254 in the feedback loop of the outfan 256 of device 250 greatly.Switch 254 (S4) were used in the pre-charging stage phase Between to capacitor 252C_intDischarge.The positive input terminal of amplifier 250 is connected to common-mode voltage input 258 (VCM).Amplify The output 256 of device 250 is expressed as follows face by the various extracting parameters driving transistor 220 and OLED 222 of explanation.

Box switch circuits 208 includes the multiple switches for controlling the electric current to and from pixel driver circuit 202 260 (S1), 262 (S2) and 264 (S3).Switch 260 (S1) are used to the discharge path of ground connection during reseting stage.Open Closing 262 (S2) provides power supply to connect during the normal operating of pixel 104 and during the integration phase read.Switch 264 (S3) it is used to make charge pump circuit 206 isolate with power line voltage 212 (VD).

As in figure 2 it is shown, the overall reading design for the double transistor pixels drive circuit 202 of each pixel 104 comes From in the fact that the electric charge that is stored on by the parasitic capacitance that represents of capacitor 240 crossing over OLED 222 two ends has and drives The threshold voltage of dynamic transistor 220 and the useful information of the conducting voltage of mobility and OLED 222.The extraction of this kind of parameter Can be used for various application.Such as, such parameter can be used to modify the programming data of pixel 104, with compensation pixel Change and holding picture quality.Such parameter also can be used to preaging pel array 102.These parameters also can be used to comment Estimate the process yields (process yield) manufacturing pel array 102.These or other parameter can pass through tool as herein described Such as monitoring line etc. is had to be connected to any image element circuit of line of image element circuit for extracting or read such parameter and quilt Extract.

Assuming that capacitor 240 (C_OLED) be initially discharged, then capacitor 240 (C_OLED) need some times to charge to make Drive the voltage level of transistor 220 cut-off.This voltage level is the function of the threshold voltage driving transistor 220.Apply extremely Programming data input 232 (V_Data) voltage must be of a sufficiently low so that the burning voltage (setteld of OLED 222 voltage)(V_OLED) less than the conducting valve threshold voltage of OLED 222 own.In the case, V_Data–V_OLEDIt is to drive transistor Threshold voltage (the V of 220_th) linear function.In order to extract the migration such as driving transistor 220 film transistor device such as grade Rate, will consider the momentary stabilization as threshold voltage and the function of mobility (transient settling) of this kind of device. Assuming that such as drive the threshold voltage deviation between transistor 220 TFT device such as grade to be compensated, then with constant after starting integration The voltage of the node 244 of interval sampling is only the function of the mobility driving transistor 220 TFT device such as grade such as paid close attention to.

Fig. 3 A to 3C be suppose drive transistor 220 be n-type transistor in the case of apply to Fig. 2 for extracting Such as the drive threshold voltage of transistor 220 and the conducting voltage of mobility and OLED 222 etc. in drive circuit 200 are joined The signal timing diagram of the control signal of the assembly of number.This kind of control signal can be applied the source drive to Fig. 1 by controller 112 Device 110, gate drivers 108 and electric current supply and reading circuit 120.Fig. 3 A shows applying to for extracting driving crystal The threshold voltage of pipe 220 and the sequential chart of the signal extracting circuit 200 of mobility.Fig. 3 A includes that the selection in Fig. 2 is defeated Enter the signal 302 of end 230, to the signal 304 switching 260Signal 306 for switch 262For switching The signal 308 of 264Signal 310 for switch 254Programming data input 232 in Fig. 2 The outfan 256 of the voltage 314 of the node 244 in program voltage signal 312, Fig. 2 and the amplifier 250 in Fig. 2 Output voltage signal 316.

Fig. 3 A shows the four-stage of readout, i.e. reseting stage 320, integration phase 322, pre-charging stage 324 With the reading stage 326.This process is by activating high selection signal 302 to selecting input 230 to start.Select signal 302 Height will be retained as in whole readout as shown in Figure 3A.

During reseting stage 320, in order to provide the discharge path of ground connection, by the input signal 304 to switch 260It is set to height.In this stage, to the signal 306 of switch 262 Signal 308 to switch 264 Signal 310 to switch 250It is retained as low.Sufficiently high voltage level (V_{RST_TFT}) to be applied to programming data defeated Enter end 232 (V_Data) to flow through the electric current maximization driving transistor 220.Therefore, the voltage quilt at the node 244 in Fig. 2 It is discharged to ground, thinks that next cycle prepares.

During integration phase 322, to the signal 304 of switch 262Remaining height, this provides from voltage source 210 Charge path by switch 262.In this stage, to the signal 304 of switch 260Signal 308 to switch 264With the signal 310 to switch 250It is retained as low.Program voltage input 232 (V_Data) it is set to voltage Level (V_{INT_TFT}) so that once capacitor 240 (C_OLED) be fully charged, the voltage at node 244 is less than OLED's 222 Conducting voltage.This situation will make during driving the reading of transistor 220 from any minimum interference of OLED 222.? Before the time of integration closes to an end, in order to make capacitor 240 (C_OLEDElectric charge on) and the remainder isolation of circuit, will deliver to Program voltage input 232 (V_Data) signal 312 be reduced to V_OFF。

When the long enough time of integration, it is stored in capacitor 240 (C_OLEDOn), electric charge will be the threshold values driving transistor 220 The function of voltage.For the time of integration shortened, the voltage at node 244 is stablized incomplete for experience and be stored in capacitor 240(C_OLEDElectric charge on) will be the function driving both the threshold voltage of transistor 220 and mobility.Therefore, feasible It is to extract the two parameter by using short integration phase and long integration phase to obtain two single readings.

During pre-charging stage 324, by the signal 304 to switch 260With the signal 306 to switch 262It is set as low.Once arrive the input signal 310 of switch 254Being set high to, amplifier 250 is just set to Unity feedback constructs.In order to the output stage of guard amplifier 250 is from the impact of the short circuit current from supply voltage 210, when arriving The signal 306 of switch 262When being set to low, to the signal 308 of switch 264Uprise.When switch 264 is closed When closing, the parasitic capacitance 242 of power line is precharged to common-mode voltage VCM.Common-mode voltage VCM must be less than OLED 222 The voltage level of conducting voltage.Before pre-charging stage closes to an end, will deliver to switch the signal 310 of 254It is set as It is low, so that charge-pump amplifier 250 is prepared for read cycle.

During reading the stage 336, will deliver to switch the signal 304 of 260Deliver to switch the signal 306 of 262With deliver to switch the signal 310 of 254It is set as low.To be used for switching the signal 308 of 264Remain Height, to provide from drive circuit 202 to the charge transfer path of charge-pump amplifier 250.By sufficiently high voltage 312 (V_{RD_TFT}) apply to program voltage input 232 (V_Data), so that driving the channel resistance of transistor 220 to minimize.If it is long-pending Divide cycle long enough, then accumulate at capacitor 252 (C_intElectric charge on) is not the function of the time of integration.Therefore, in this case The output voltage of charge-pump amplifier 250 be equal to:

$V_{out}=-\frac{C_{oled}}{C_{\mathrm{int}}}(V_{Data}-V_{th})$

For the time of integration shortened, accumulation is at capacitor 252 (C_intElectric charge on) is given by the following formula:

$Q_{\mathrm{int}}=\stackrel{T_{\mathrm{int}}}{\∫}{i}_D(V_{GS},V_{th},\mathrm{\μ}).dt$

Therefore, the charge-pump amplifier 250 output voltage 256 at the end of read cycle is equal to:

$V_{out}=-\frac{1}{C_{\mathrm{int}}}\·\stackrel{T_{\mathrm{int}}}{\∫}{i}_D(V_{GS},V_{th},\mathrm{\μ}).dt$

Therefore, it can by the centre in reading stage 326 and at the end of read cycle 326 read-out amplifier 250 Output voltage 256 extract and drive the threshold voltage of transistor 220 and mobility.

Fig. 3 B is the sequential chart of the reading process of the threshold values conducting voltage parameter of the OLED 222 in Fig. 2.OLED The reading process of 222 includes four-stage equally: reseting stage 340, integration phase 342, pre-charging stage 344 and the stage of reading 346.As the reading process driving transistor 220 in Fig. 3 A, the reading process of OLED is by using high selection signal 302 activate selection input 230 and start.Deliver to switch the signal 304 of 260Deliver to switch the signal 306 of 262Deliver to switch the signal 308 of 264With deliver to switch the signal 310 of 254Sequential and Fig. 3 A in The reading process driving transistor 220 is identical.For the programming signal 332 that input 232 is programmed, for the letter of node 244 Numbers 334 different from the signal in Fig. 3 A with the output signal 336 of the output for amplifier 250.

During reseting stage 340, by sufficiently high voltage level 332 (V_{RST_OLED}) apply to programming data input 232(V_Data), to flow through the electric current maximization driving transistor 220.Therefore, the voltage at the node 244 in Fig. 2 is by opening Close 260 and be discharged to ground, think that next cycle prepares.

During integration phase 342, deliver to switch the signal 306 of 262Remaining height, this provides from voltage source 210 through the charge path switching 262.Program voltage input 232 (V_Data) it is set to voltage level 332 (V_{INT_OLED}), Make once capacitor 240 (C_OLED) be fully charged, the voltage at node 244 is greater than the conducting voltage of OLED 222. In the case, at the end of integration phase 342, drive transistor 220 to drive constant current by OLED 222 always.

During pre-charging stage 344, make 220 sections of driving transistor by delivering to program the signal 332 of input 232 Only.Capacitor 240 (C_OLED) it is allowed to electric discharge, until it reaches the conducting voltage of OLED 222 at the end of pre-charging stage 344.

During reading the stage 346, by sufficiently high voltage 332 (V_{RD_OLED}) apply to program voltage input 232 (V_Data), so that driving the channel resistance of transistor 220 to minimize.If pre-charging stage long enough, then capacitor 252 (C_int) burning voltage at two ends will not be the function of precharge time.Therefore, charge-pump amplifier at the end of the reading stage The output voltage 256 of 250 is given by the following formula:

$V_{out}=-\frac{C_{oled}}{C_{\mathrm{int}}}\·V_{ON,oled}$

By the signal 308 to switch 264Remain height, to provide from drive circuit 202 to charge-pump amplifier The charge transfer path of 250.Therefore, output voltage signal 336 can be used for determining the conducting voltage of OLED 220.

Fig. 3 C is for using the sequential chart directly read driving transistor 220 extracting circuit 200 in Fig. 2.Directly Connect reading process and there is reseting stage 350, pre-charging stage 352 and integration/reading stage 354.This readout is by activating Selection input 230 in Fig. 2 and start.In whole readout as shown in Figure 3 C, deliver to select the choosing of input 230 Select signal 302 and be retained as height.Signal 364 for switch 260With the signal 366 for switch 262At this Readout is invalid (inactive).

During reseting stage 350, in order to provide the discharge path of virtual ground, will be used for switching the signal 368 of 264With the signal 370 for switch 254It is set as height.By sufficiently high voltage 372 (V_{RST_TFT}) apply to programming Input 232 (V_Data), to flow through the electric current maximization driving transistor 220.Therefore, node 244 is discharged to common mode electricity Pressure 374 (VCM_RST), think that next cycle prepares.

During pre-charging stage 354, by by blanking voltage 372 (V_OFF) apply the programming input 232 to Fig. 2 Driving transistor 220 is made to end.In order to line capacitance is pre-charged, being total to of the positive input terminal of amplifier 250 will be delivered to Mode voltage input 258 improves to VCM_RD.At the end of pre-charging stage 354, make to deliver to switch the signal 370 of 254Cut Only, so that charge-pump amplifier 250 was prepared for next cycle.

When integration/reading stage 356 starts, by program voltage input 232 (V_Data) improve to making driving transistor The V of 220 conductings_{INT_TFT}372.Capacitor 240 (C_OLED) start stored charge, until V_DataDeduct the voltage etc. at node 244 In the threshold voltage driving transistor 220.Meanwhile, proportional electric charge is accumulated in capacitor 252 (C_INTIn).Therefore, At the end of read cycle 356, the output voltage 376 of the outfan 256 of amplifier 250 is the threshold values electricity be given by equation below The function of pressure:

$V_{out}=\frac{C_{oled}}{C_{\mathrm{int}}}\·(V_{Data}-V_{th})$

As represented by above-mentioned formula, in the case of directly reading, output voltage has positive polarity.Therefore, crystal is driven The threshold voltage of pipe 220 can be determined by the output voltage of amplifier 250.

As it has been described above, the driving transistor 220 in Fig. 2 can be p-type transistor.Fig. 4 A to 4C is to drive transistor 220 apply when being p-type transistor to Fig. 2 for from driving transistor 220 and OLED 222 to extract threshold voltage and migration The signal timing diagram of the signal of the assembly of rate.In the example driving transistor 220 to be p-type transistor, drive transistor 220 Source electrode is connected to supply lines 212 (VD) and drives the drain electrode of transistor 220 to be connected to OLED 222.Fig. 4 A shows and is driving Apply when transistor 220 is p-type transistor to for from the extraction circuit driving transistor 220 to extract threshold voltage and mobility The sequential chart of the signal of 200.Fig. 4 A show the selection input 232 in Fig. 2, switch 260, switch 262, switch 264, Voltage at switch 254, programming data input 230, node 244 and the voltage signal 402 to 416 of output voltage 256.With The following three stage carries out data extraction: reseting stage 420, integration/pre-charging stage 422 and read the stage 424.

As shown in Figure 4 A, select signal 402 be Low level effective and in the whole reading stage 420,422 and 424 quilt Remain low.In whole readout, deliver to switch the signal 404 of 260With deliver to switch the signal 406 of 262It is retained as low (invalid).In reseting stage, in order to node 244 is charged to reset common mode voltage level VCM_rst, The signal 408 at 264 will be switchedWith the signal 410 switched at 254It is set as height.On electric charge pump input 258 Common-mode voltage input 258 (VCM_rst) should be of a sufficiently low, to keep OLED222 to end.By programming data input 232V_Data It is set as of a sufficiently low value 412 (V_{RST_TFT}), to provide the maximum charging current by driving transistor 220.

During integration/pre-charging stage 422, by the common mode voltage reduction on common-mode voltage input 258 to VCM_intAnd Will programming input 232 (V_Data) increase to level 412 (V_{INT_TFT}) so that drive transistor 220 to lead in the opposite direction Logical.If the distribution time long enough in this stage, then the voltage at node 244 will be decreased until the grid driving transistor 220 Reach to drive the threshold voltage of transistor 220 to source voltage.Before this end cycle, in order to make charge-pump amplifier 250 Prepare for the reading stage 424, deliver to switch the signal 410 of 254Step-down.

By input 232 (V will be programmed_Data) signal 412 at place is decreased to V_{RD_TFT}So that driving transistor 220 to turn on Start the stage of reading 424.Now, will be stored in capacitor 240 (C_OLEDElectric charge on) transmits to capacitor 254 (C_INT).? At the end of the reading stage 424, in order to make charge-pump amplifier 250 isolate with drive circuit 202, will deliver to switch the signal of 264 408It is set as low.Now, from the output voltage signal 416V of amplifier out 256_outIt is to be given by equation below The function of threshold voltage driving transistor 220:

$V_{out}=-\frac{C_{oled}}{C_{\mathrm{int}}}(L_{INT\_TFT}-V_{th})$

Fig. 4 B is the threshold values of the OLED 222 in the case of supposition drives transistor 220 to be p-type transistor in Fig. 2 The sequential chart extracted in the pixel of voltage.This extraction process and the extraction circuit driving transistor for N-shaped delivered in Fig. 3 A The sequential of the signal of 200 is similar.Fig. 4 B shows the selection input 230 in Fig. 2, switch 260, switch 262, opens Voltage at pass 264, switch 254, programming data input 232, node 244 and the voltage signal of amplifier out 256 432 to 446.Extraction process includes reseting stage 450, integration phase 452, pre-charging stage 454 and reading stage 456.This reads Going out the cycle main distinction compared with the readout interval in Fig. 4 A is to apply to drive circuit 210 extremely in each reading stage Programming data input 232 (V_Data) the voltage level of signal 442.P-type thin film for can be used for driving transistor 220 is brilliant Body pipe, the signal 430 that selects delivering to select input 232 is Low level effective.At whole readout as shown in Figure 4 B In, select input 232 to be retained as low.

First readout by making capacitor 240 (C in reseting stage 450_OLED) reset and start.Switch will be delivered to The signal 434 of 260It is set as height, to provide the discharge path of ground connection.In order to make driving transistor 220 turn on, will deliver to Programming input 232 (V_Data) signal 442 be reduced to V_{RST_OLED}。

In integration phase 452, will deliver to switch the signal 434 of 260With the signal 436 to switch 262 It is respectively set as cut-off state and conducting state, to provide the charge path of OLED 222.Capacitor 240 (C_OLED) be allowed to It is charged, until the voltage 444 at node 244 exceeds the threshold voltage of OLED 222 so that OLED 222 turns on.At integration Before stage 452 terminates, deliver to program input 232 (V_Data) voltage signal 442 improve to V_OFFSo that driving transistor 220 cut-offs.

During pre-charging stage 454, capacitor 240 (C_OLEDStored charge on) is discharged in OLED 222, directly Voltage 444 at node 244 reaches the threshold voltage of OLED 222.And, in pre-charging stage 454, delivering to switch The signal 438 of 264With deliver to switch the signal 440 of 254While being set to conducting, deliver to switch 260 Signal 434With deliver to switch the signal 436 of 262Cut-off.This provides supply lines 212 for amplifier 250 (VD) it is precharged to be arranged on the common-mode voltage input 258 (VCM) at the positive input terminal of amplifier 250 and provides condition.? At the end of pre-charging stage, make to deliver to switch the signal 430 of 254Cut-off, so that charge-pump amplifier 250 is for reading rank Section 456 is prepared.

The reading stage 456 is by delivering to programming input 232 (V_Data) voltage 442 be reduced to V_{RD_OLED}Time make to drive Dynamic transistor 220 turns on and starts.Now, capacitor 240 (C it is stored in_OLEDElectric charge on) is transferred to capacitor 254 (C_INT), the output voltage 446 at the outfan 256 of amplifier 250 is configured to the threshold voltage of OLED 220 by this capacitor Function.

Fig. 4 C is the driving crystal in the extraction system 200 in Fig. 2 when driving transistor 220 is p-type transistor The signal timing diagram of the extracting directly of the threshold voltage of pipe 220.Fig. 4 C shows the selection input 230 in Fig. 2, switch 260, the voltage at switch 262, switch 264, switch 254, programming data input 232, node 244 and output voltage 256 Voltage signal 462 to 476.This extraction process includes pre-charging stage 480 and integration phase 482.But, in figure 4 c time Sequence figure illustrates the special last reading stage 484, if to charge-pump amplifier 250 at the end of integration phase 482 Output is sampled, then can eliminate the reading stage 484.

This extraction process by simultaneously storing capacitor 224, source electrode storage capacitor 226, electric capacity to the drain electrode in Fig. 2 Device 240 (C_OLED) and capacitor 242 be pre-charged and start.Deliver to select line input to this end, activate as shown in Figure 4 C The signal 462 of 230, deliver to switch the signal 468 of 264 and deliver to switch the signal 470 of 254.In whole readout, deliver to The signal 404 of switch 260With deliver to switch the signal 406 of 262It is retained as low.Common-mode voltage input 258 (VCM) voltage level determines the voltage on supply lines 212 and thus determines the voltage at node 244.Common-mode voltage (VCM) should When of a sufficiently low so that OLED 222 is not turned on.Deliver to program input 232 (V_Data) voltage 472 be set to of a sufficiently low Level (V_{RST_TFT}) so that transistor 220 turns on.

When integration phase 482 starts, in order to make the overdrive electric current of transistor 220 of charge-pump amplifier 250 convection current enter Row integration, will deliver to switch the signal 470 of 254Cut-off.As the threshold voltage and its grid that drive transistor 220 The function of pole-source voltage, the output voltage 256 of charge-pump amplifier 250 will rise with constant speed.In integration phase Before 482 terminate, make to deliver to switch the signal 468 of 264Cut-off, so that charge-pump amplifier 250 and drive circuit 220 isolation.Therefore, the output voltage 256 of amplifier 250 is given by the following formula:

$V_{out}=I_{TFT}\·\frac{T_{int}}{C_{\mathrm{int}}}$

Here, I_TFTBe drive transistor 220 as mobility and (V_CM-V_Data-|V_th|) function drain current.T_int It is the length of the time of integration.Read in the stage 484 optional, deliver to switch the signal 468 of 264It is cut off, so that Charge-pump amplifier 250 is isolated with drive circuit 202.Can be in any time in reading the stage 484 to as driving crystalline substance The output voltage 256 of the mobility of body pipe 220 and the function of threshold voltage is sampled.

Fig. 4 D is the sequential chart directly read of the OLED 222 in Fig. 2.When using sufficiently high gate-to-source electricity When pressure makes driving transistor 220 turn on, transistor 220 is driven to be used as the simulation of the anode terminal for accessing OLED 222 Switch.In the case, the voltage at node 244 is substantially equal to the voltage on supply lines 212 (VD).Therefore, by driving The electric current that drives of transistor 220 will be only the function of the voltage set on the conducting voltage of OLED 222 and supply lines 212.Should Drive electric current can be provided by charge-pump amplifier 250.When being integrated in certain time period, the output electricity of integrating circuit 206 Pressure 256 is exactly how many measurement weathered to OLED 222.

Fig. 4 D shows applying to for via directly reading the extraction circuit 200 extracting conducting voltage from OLED 222 The sequential chart of signal.Fig. 4 D shows the three phases of readout, i.e. pre-charging stage 486, integration phase 487 and reading Stage 488.Fig. 4 D includes signal 489n or 489p of the selection input 230 in Fig. 2, delivers to switch the signal 490 of 260Signal 491 for switch 262Signal 492 for switch 264Letter for switch 254 Numbers 493Node in program voltage signal 494n of the programming data input 232 in Fig. 2 or 494p, Fig. 2 The output voltage signal 496 of the outfan 256 of the voltage 495 of 244 and the amplifier 250 in Fig. 2.

This process starts by activating the selection signal corresponding with the desired row of the pixel in array 102.Such as Fig. 4 D Shown in, select signal 489n to select transistor high level effective for N-shaped, and select transistor Low level effective for p-type. In the case of N-shaped drives transistor, high selection signal 489n is applied to selecting input 230.For driving transistor 220, in the case of p-type drives transistor, low signal 489p is applied to selecting input 230.

During precharge cycle 486 and integration period 487, select signal 489n or 489p will be kept effectively.At this In reading method,Input 490 HesInput 491 invalid.During precharge cycle, in order to provide signal path, will open OFF signal 492With switching signal 493It is set as height, so that power line (C_P) parasitic capacitance 242 and node 244 at Voltage is precharged to the common-mode voltage (VCM that the non-inverting terminals of amplifier 250 is provided_OLED).Electricity is driven by sufficiently high Pressure signal 494n (V_{ON_nTFT}) or 494p (V_{ON_pTFT}) apply to data input pin 232 (V_Data), so that driving transistor 220 to make Operate for analog switch.Therefore, supply voltage 212VD and node 244 are precharged to common-mode voltage (VCM_OLED), think next Cycle prepares.When integration phase 487 starts, in order to make electric charge pump module 206 that the electric current of OLED 222 to be integrated, make Switch input 493Cut-off.As voltage 495 (that is, the VCM set in the conducting voltage of OLED 222 and node 244_OLED) Function, the output voltage 496 of electric charge pump module 206 will rise with constant speed.Before integration phase 487 terminates, make Switching signal 492Cut-off, so that electric charge pump module 206 is isolated with image element circuit 202.After at the moment, output voltage is permanent It is fixed until electric charge pump module 206 is reset in order to another reads.When being integrated in certain time period, the output of integrator Voltage is given by the following formula:

$V_{out}=I_{OLED}\frac{T_{\mathrm{int}}}{C_{\mathrm{int}}}$

It is the measurement to OLED degree of aging.T in this formula_intIt it is switching signal 493Trailing edge to opening OFF signal 492Trailing edge between time interval.

The similar extraction process that can utilize the bicrystal cast drive circuits such as the drive circuit in such as Fig. 2 carries Take the such as threshold voltage of three transistor-type drive circuits of the part as data extraction system 500 as shown in Figure 5 With heterogeneity and ageing parameters such as mobilitys.Data extraction system 500 includes drive circuit 502 and reading circuit 504.As Electric current supply and the part of reading circuit 120, reading circuit 504 from string pixel 104 as shown in Figure 1 collect data and Including charge pump circuit 506 and box switch circuits 508.Supply voltage (VDD) is provided to drive circuit 502 by voltage source 510.Electricity Lotus pump circuit 506 and box switch circuits 508 are used in the top side of array 102 or bottom side, and (voltage the most in FIG drives Dynamic 114 and electric current supply and reading circuit 120 in).This is by the direct manufacture on the substrate identical with pel array 102 Or by microchip being bonded on substrate or by realizing as the flex of hybrid solution.

Drive circuit 502 includes driving transistor 520, organic luminescent device 522, drain electrode storage capacitor 524, source electrode to deposit Storage capacitor 526 and selection transistor 528.Line input 530 is selected to be connected to select the grid of transistor 528.Programming input End 532 is connected to drive the grid of transistor 220 by selecting transistor 528.Line input 530 is selected to be also connected to output crystalline substance The grid of body pipe 534.Output transistor 534 is connected to drive source electrode and the voltage monitoring output lead 536 of transistor 520.Drive The drain electrode of transistor 520 is connected to power voltage source 510 and drives the source electrode of transistor 520 to be connected to OLED 522.Source electrode is deposited Storage capacitor 526 is connected between grid and the source electrode of driving transistor 520.Drain electrode storage capacitor 524 is connected to drive crystalline substance Between grid and the drain electrode of body pipe 520.OLED 522 has the parasitic capacitance being modeled as capacitor 540.Monitoring output voltage Line 536 has the parasitic capacitance being modeled as capacitor 542 equally.Driving transistor 520 in this example is by non-crystalline silicon system The thin film transistor (TFT) become.Voltage node 544 is the point between source terminal and the OLED 522 driving transistor 520.Originally showing In example, driving transistor 520 is n-type transistor.Can use p-type drive transistor replace drive transistor 520 realize be System 500.

Reading circuit 504 includes charge pump circuit 506 and box switch circuits 508.Charge pump circuit 506 is included in negative feedback Ring has capacitor 552 (C_int) amplifier 550.Between precharge phase, switch 554 (S4) is utilized to come capacitor 552 (C_int) discharge.Amplifier 550 has and capacitor 552 and the negative input ends that are connected of switch 554 and defeated with common-mode voltage Enter the positive input terminal that end 558 (VCM) connects.Amplifier 550 has the face of the being expressed as follows driving transistor 520 and OLED by explanation The outfan 556 of the various extracting parameters of 522.

Box switch circuits 508 includes for guiding electric current to and from multiple switches 560,562 and of drive circuit 502 564.Switch 560 is used to the discharge path of ground connection during reseting stage.Switch 562 is in the normal operating of pixel 104 Period and offer power supply connection during the integration phase of readout.Switch 564 is used to make charge pump circuit 506 and electricity Source line voltage source 510 isolates.

In three transistor driver circuits 502, it is read out normal through monitoring line 536.Can also with Fig. 3 A to 3C In the similar mode of the process of clock signal be read out by the voltage power line of power voltage source 510.For switch 560 Input signalThe input signal of switch 562The input signal of switch 564The input of switch 554 SignalSelect input 530 and program voltage input 532 (V_Data) accurate sequential be used to control read electricity The performance on road 500.During each stage of readout, some voltage level is applied to programming data input 532 (V_Data) and common-mode voltage input 558 (VCM).

Three transistor-type drive circuits 502 can by program voltage input 532 with monitoring outfan 536 discriminatively It is programmed.Therefore, reseting stage and pre-charging stage can be merged together formation reset/pre-charging stage, this reset/pre- It is integration phase and reading stage after charging stage.

Fig. 6 A relates to the sequential chart of the signal of the extraction of the threshold voltage driving transistor 520 in Fig. 5 and mobility. This sequential chart includes the selection input 530 in Fig. 5, switch 560, switch 562, switch 564, switch 554, program voltage Input 532, drive the voltage letter of the voltage at the grid of transistor 520, voltage at node 544 and output voltage 556 Numbers 602 to 618.Readout in Fig. 6 A has pre-charging stage 620, integration phase 622 and reading stage 624.This reading Process by simultaneously drain-capacitor 524, source capacitor 526 and capacitor parasitics 540 and 542 being pre-charged and Start.To this end, as shown in Figure 6A activate select line voltage 602, deliver to switch 564 signal 608With deliver to switch The signal 610 of 554In whole readout interval, deliver to switch the signal 604 of 560With deliver to switch 562 Signal 606Remain low.

The voltage level of common mode input 558 (VCM) determines the voltage on output monitoring line 536 and thus determines node Voltage at 544.Voltage to common mode input 558 (VCM) should be of a sufficiently low, so that OLED 522 is not turned on.In precharge In stage 620, deliver to program voltage input 532 (V_Data) the sufficiently high (V of voltage signal 612_{RST_TFT}) so that driving transistor 520 conductings, and also of a sufficiently low so that OLED 522 is always maintained at cut-off.

When integration phase 622 starts, make the voltage 602 delivering to select input 530 invalid, so that electric charge can be deposited Capacitor 540 (C is arrived in storage_OLEDOn).Voltage at node 544 will begin to ramp up, and drive the grid voltage of transistor 520 to incite somebody to action With the capacitance of source capacitor 526 relative to the ratio [C of source capacitor 526 and the capacitance of drain-capacitor 524_S1/ (C_S1+C_S2)] follow the voltage rising at node 544.Once drive the voltage at grid voltage and the node 544 of transistor 520 Difference equal to driving the threshold voltage of transistor 520, charging just will complete.Before integration phase 622 terminates, make to deliver to switch The signal 610 of 554Cut-off, so that charge-pump amplifier 550 was prepared for the reading stage 624.

About reading the stage 624, again activate the signal 602 delivering to select input 530.On programming input 532 Voltage signal 612 (V_{RD_TFT}) of a sufficiently low so that driving transistor 520 to keep cut-off.Now, capacitor 240 (C it is stored in_OLED) On electric charge be transferred to capacitor 254 (C_INT) and produce the output voltage proportional to the threshold voltage driving transistor 520 618:

$V_{out}=-\frac{C_{oled}}{C_{\mathrm{int}}}(V_G-V_{th})$

Before reading stage 624 end, deliver to switch the signal 608 of 564Cut-off is so that charge pump circuit 506 Isolate with drive circuit 502.

Fig. 6 B is the sequential chart of the input signal of the extraction of the conducting voltage of the OLED 522 in Fig. 5.Fig. 6 B includes Selection input 530 in Fig. 5, switch 560, switch 562, switch 564, switch 554, program voltage input 532, drive Voltage at the grid of dynamic transistor 520, voltage, common-mode voltage input 558 and output voltage 556 at node 544 Voltage signal 632 to 650.Readout in Fig. 6 B has pre-charging stage 652, integration phase 654 and reading stage 656. Be similar to in Fig. 6 A drive transistor 220 reading, readout with in pre-charging stage 652 simultaneously to drain electrode The mode that capacitor 524, source capacitor 526 and capacitor parasitics 540 and 542 carry out being pre-charged starts.To this end, such as Fig. 6 B Shown activation is delivered to select the signal 632 of input 530, deliver to switch the signal 638 of 564With deliver to switch 554 Signal 640In whole readout interval, signal 634With signal 636Remain low.Deliver to common mode electricity Input voltage 648 (the VCM of pressure input 258_Pre) should be high enough that OLED 522 is switched on.Deliver to program input 532 (V_Data) voltage 642 (V_{Pre_OLED}) of a sufficiently low to keep driving transistor 520 to end.

When integration phase 654 starts, the voltage 632 making to deliver to select input 530 is invalid, so that electric charge can be by Capacitor 540 (C is arrived in storage_OLEDOn).Voltage at node 544 will begin to decline, and drive the grid voltage of transistor 520 By with the capacitance of source capacitor 526 relative to the ratio [C of source capacitor 526 and the capacitance of drain-capacitor 524_S1/ (C_S1+C_S2)] follow the voltage decline at node 544.Once the voltage at node 544 reaches the conducting voltage of OLED 522 (V_OLED), electric discharge just completes.Before integration phase 654 terminates, make to deliver to switch the signal 640 of 554Cut-off, so that Charge pump circuit 506 was prepared for the reading stage 656.

About reading the stage 656, again activate the signal 632 delivering to select input 530.On programming input 532 Voltage signal 642 (V_{RD_OLED}) should be of a sufficiently low so that driving transistor 520 to keep cut-off.Then, capacitor 540 it is stored in (C_OLEDElectric charge on) is transferred to capacitor 552 (C_INT), thus produce and the leading of OLED 522 at electric discharge outfan 556 The output voltage 650 of the ratio that is pressed into that is energized:

$V_{out}=-\frac{C_{oled}}{C_{\mathrm{int}}}\·V_{ON,oled}$

At the front signal 638 reading stage 656 endCut-off, so that charge pump circuit 508 and drive circuit 502 Isolation.

As it can be seen, monitoring output transistor 534 is to drive transistor 520 or OLED 522 to provide the line for electric current The directapath of property integration.Reading can be performed in precharge cycle and integration period.But, Fig. 6 C shows for additionally The sequential chart of the last input signal reading the stage, if the output to charge pump circuit 508 is adopted at the end of integration phase Sample, then can eliminate this reading stage.Fig. 6 C includes the selection input 530 in Fig. 5, switch 560, switch 562, switch 564, the voltage signal 662 of switch 554, program voltage input 532, voltage at node 544 and output voltage 556 to 674.Therefore, the readout in Fig. 6 C has pre-charging stage 676, integration phase 678 and optional reading stage 680.

N-shaped in Fig. 5 as shown in Figure 6 C drives the direct integral readout of transistor 520 by simultaneously to drain electrode Capacitor 524, source capacitor 526 and capacitor parasitics 540 and 542 are pre-charged and start.To this end, as shown in Figure 6 C Ground activates to be delivered to select the signal 660 of input 530, deliver to switch the signal 666 of 564With deliver to switch the signal of 554 668In whole readout interval, deliver to switch the signal 662 of 560With deliver to switch the signal 664 of 562Remain low.The voltage level of common-mode voltage input 558 (VCM) determine monitoring output lead 536 on voltage and because of And determine the voltage at node 544.Voltage signal (the VCM of common-mode voltage input 558_TFT) of a sufficiently low so that OLED 522 not Conducting.Deliver to program input 532 (V_Data) signal 670 (V_{ON_TFT}) it is high enough that driving transistor 520 turns on.

When integration phase 678 starts, in order to make charge-pump amplifier 550 can to come self-driven transistor 520 electricity Stream is integrated, and makes to deliver to switch the signal 668 of 554Cut-off.As driving the threshold voltage of transistor 520, mobility With the function of grid-source voltage, the output voltage 674 of charge-pump amplifier 550 declines with constant speed.In integration phase Before end, make to deliver to switch the signal 666 of 564Cut-off, so that charge pump circuit 508 is isolated with drive circuit 502. Therefore, output voltage is given by the following formula:

$V_{out}=-I_{TFT}\·\frac{T_{\mathrm{int}}}{C_{\mathrm{int}}}$

Here, I_TFTBe drive transistor 520 as mobility and (V_Data-V_CM-V_th) the drain current of function.T_int It is the length of the time of integration.Can be in any time in reading the stage 680 to as mobility and the valve driving transistor 520 The output voltage 674 of the function of threshold voltage is sampled.

Fig. 6 D show the input signal directly read of conducting (threshold values) voltage of the OLED 522 in Fig. 5 time Sequence figure.Fig. 6 D includes the selection input 530 in Fig. 5, switch 560, switch 562, switch 564, switch 554, programming electricity Voltage at pressure input 532, node 544 and the voltage signal 682 to 696 of output voltage 556.Readout in Fig. 6 C There is pre-charging stage 697, integration phase 698 and optional reading stage 699.

Readout in Fig. 6 D is by simultaneously to drain-capacitor 524, source capacitor 526 and capacitor parasitics 540 and 542 are pre-charged and start.To this end, be activated to as shown in Figure 6 D deliver to the signal 682 of selection input 530, send Signal 688 to switch 564With deliver to switch the signal 690 of 554In whole readout interval, signal 684With signal 686Remain low.The voltage level of common-mode voltage input 558 (VCM) determines monitoring output lead Voltage on 536 also thus determines the voltage at node 544.Voltage signal (the VCM of common-mode voltage input 558_OLED) enough It is high so that OLED 522 turns on.Programming input 532 (V_Data) signal 692 (V_{OFF_TFT}) of a sufficiently low so that driving transistor 520 Keep cut-off.

When integration phase 698 stage starts, in order to make the charge-pump amplifier 550 can be to the electric current from OLED 522 It is integrated, makes to deliver to switch the signal 690 of 552Cut-off.Threshold voltage and OLED 522 liang as OLED 522 The function of the voltage of end, the output voltage 696 of charge-pump amplifier 550 will rise with constant speed.

Before integration phase 698 terminates, make to deliver to switch the signal 688 of 564Cut-off, so that charge pump circuit 508 isolate with drive circuit 502.Therefore, output voltage is given by the following formula:

$V_{out}=I_{OLED}\·\frac{T_{\mathrm{int}}}{C_{\mathrm{int}}}$

Here, I_OLEDIt is as (V_CM-V_th) the OLED current of function, and T_intIt is the length of the time of integration.Can read The output voltage of the function of the threshold voltage as OLED 522 is sampled by any time in during taking the stage 699.

Skilled artisan will appreciate that of computer, software and network field, can by using according to as noted herein and Illustrated teaching and program one or more general-purpose computing systems, microprocessor, digital signal processor, microcontroller Device, special IC (ASIC), PLD (PLD), field programmable logic device (FPLD) and scene can be compiled Journey gate array (FPGA) etc. conveniently realizes the controller 112 in Fig. 1.

Can be replaced by any controller described herein additionally, two or more calculate system or equipment.Therefore, also Can desirably realize the principle and advantage of such as redundancy and duplication equal distribution process to increase controller described herein Robustness and performance.Controller also can be in computer system or using appointing of any suitable interface mechanism and communication technology Being implemented in the system of extension in meaning network environment, described communication technology such as includes telecommunications (such as, the sound of any appropriate format Sound and modem etc.), public switched telephone network (PSTN), enfeoffment data network (PDN), the Internet, Intranet and it Combination etc..

Operation example data being extracted process with reference to the flow chart shown in Fig. 7 illustrates.Flow process in Fig. 7 Figure represents for being determined to make the threshold voltage of the maximized simple drive circuit in aperture of the pixel 104 in Fig. 1 and moving The example machine readable of shifting rate.In this example and other flowchart illustration any herein, machine readable instructions Including the algorithm performed by (a) processor, (b) controller and/or (c) other suitable processing means one or more.Described Algorithm can be embodied in and be stored in such as flash memory, CD-ROM, floppy disk, hard disk drive, digitized video (general) CD (DVD) in the software or in the entity medium such as other storage device, however those of ordinary skill in the art it will be readily understood that, Alternately, whole algorithms and/or some algorithm can be performed by equipment rather than processor, and/or with many weeks The mode known implements in firmware or specialized hardware that (such as, it can be by special IC (ASIC), programmable logic device Part (PLD), field programmable logic device (FPLD), field programmable gate array (FPGA) and discrete logic etc. realize).Example As, the arbitrary of abstraction sequence or all component can be realized by software, hardware and/or firmware.And, can manually realize by The some or all of machine readable instructions that flow chart (including Fig. 7) herein represents.Although it addition, with reference to illustrating herein Flow chart (including Fig. 7) exemplary algorithm is illustrated, but those of ordinary skill in the art it will be readily understood that, can Alternatively, it is possible to use a lot of other methods performing example machine readable.For example, it is possible to the execution changing module is suitable Sequence, and/or can change, eliminate or combine some modules.

Studied pixel or image element circuit 104 (700) is selected by the selection and line program conducting making correspondence.Once Have selected pixel 104, just perform reading with four-stage.Readout by first in reseting stage to OLED (C_oled) two The parasitic capacitance of end carries out discharging and starting (702).It follows that make driving transistor turns measure sometime, this makes some electricity Lotus can be accumulated in OLED C_oledOn the electric capacity at two ends (704).In integration phase, make selection transistor cutoff, so that OLED C_oledCharge separation on the electric capacity at two ends and subsequently by circuit parasitic capacitance (C_P) it is precharged to known voltage electricity Flat (706).Finally, in the reading stage, again make driving transistor turns, so that OLED C_oledElectricity on the electric capacity at two ends Lotus can be transferred to charge-pump amplifier outfan (708).The output of amplifier represents as mobility and threshold voltage The amount of function.Described readout is by cancelling selected pixel in other pixel while being corrected to prevent interference and complete (710) become.

Fig. 8 is the difference of the image element circuits such as three transistor circuits in the transistor circuit in such as Fig. 2 and Fig. 5 Extracting cycle and the flow chart of parameter application.One process relates to integration (800) in the pixel that electric charge transmits.By with pay close attention to The charge accumulation (802) in the internal capacitance of pixel that parameter is relevant.Then, such as electric charge pump or integrator are transferred the charge to Deng outside reading circuit to set up proportion expression voltage (804).Another process is from pixel integration (off-pixel Or direct integral (810) integration).Come directly by outside reading circuit such as such as electric charge pump or integrator circuit etc. Device current is integrated (812).

During the two, the voltage produced is carried out post processing, to obtain the threshold voltage such as driving transistor Or the parameter (820) of the concern such as the conducting voltage of mobility or OLED.Then, the parameter of extraction can be used for various application (822).The example using these parameters includes according to the parameter modification programming data extracted to compensate pixel change (824).Another example is that the panel to pixel carries out preaging (826).Another example is the face of the pixel after assessment manufactures The process yields (828) of plate.

Fig. 9 is block diagram and the flow chart of the assembly of data extraction system, and described data extraction system includes image element circuit 900, switch enclosure 902 and can be the reading circuit 904 of electric charge pump/integrator.The constituent components (910) of image element circuit 900 Including such as OLED etc. light-emitting device, such as drive storage devices such as driving means, the such as capacitor such as transistor and such as Switch etc. is selected to access switch.The constituent components 912 of switch enclosure 902 includes the one group of electronic cutting that can be controlled by external control signal Close.The constituent components 914 of reading circuit 904 includes amplifier, capacitor and reset switch.

The parameter of concern can be stored as shown in frame 920.The parameter paid close attention in this example can include driving transistor Threshold voltage, the mobility driving transistor and the conducting voltage of OLED.The function frame 922 of switch enclosure 902 represents.Described Function include handling the electric current inside and outside image element circuit 900, provide be positioned at image element circuit 900 and reading circuit 904 electric charge pump it Between discharge path and make the electric charge pump of reading circuit 904 isolate with image element circuit 900.The function frame of reading circuit 904 924 represent.One function includes in step 800 in fig. 8 is to 804, in pixel in the case of integration, in the future The capacitor to reading circuit 904 is transmitted from the electric charge of the internal capacitance of image element circuit 900, proportional to this electric charge to produce Voltage.Another function includes in step 810 in fig. 8 is to 814, to image element circuit 900 in sometime The electric current driving transistor or OLED be integrated, to produce the voltage with described current in proportion.

The driving threshold voltage of transistor 520 in the revision of the circuit that Figure 10 relates to Fig. 5 and carrying of mobility The sequential chart of the signal taken, in this revision, the grid of output transistor 534 be connected to single control signal wire RD and It it not SEL line.Readout in Figure 10 has pre-charging stage 1001, integration phase 1002 and reading stage 1003.In advance During charging stage 1001, make at grid and the source electrode of driving transistor 520 by making SEL signal and RD signal be height V_AAnd V_BIt is reset to initial voltage.

During integration phase 1002, signal RD step-down, grid voltage V_AIt is maintained at V_init, and source electrode (node 544) place Voltage V_BRecharged the voltage to the function as TFT characteristic (it includes mobility and threshold voltage), such as, (V_init–V_T)。 If integration phase 1002 long enough, voltage V_BTo be only threshold voltage (V_T) function.

During reading the stage 1003, signal SEL is low, V_ADrop to (V_init+Vb–V_T) and V_BDrop to V_b.Reading In circuit 504, electric charge total capacitance C at node 544_TIt is transferred to integrated capacitor (C_int)552.Can be by making electricity consumption The analog-digital converter (Analog-to-Digital Convertor, ADC) of the output of lotus amplifier 550 reads output Voltage V_out.Alternately, it is possible to use comparator is adjusting V_initWhile output voltage is compared with reference voltage, Until the two voltage becomes identical.Described reference voltage can produce in the following way: is not having in during a stage There is any pixel in the case of being connected to circuit, circuit to be sampled, and in another stage, pixel charge is taken Sample.

Figure 11 is the input signal of the extraction of the conducting voltage of the OLED 522 in the revision of the circuit of Fig. 5 Sequential chart.

Figure 12 is for by externally initializing the circuit diagram that node carrys out the image element circuit of read pixel state.Drive crystalline substance Body pipe T1 have source electrode that the drain electrode being connected with supply voltage Vdd is connected with OLED D1 and via switching transistor T2 with The grid that Vdata line connects.The grid of transistor T2 is connected to write line WR.Storage capacitor Cs is connected to node A, and (it is positioned at Drive between grid and the transistor T2 of transistor T1) and node B (it is between source electrode and the OLED driving transistor T1) Between.Read transistor T3 to be connected to node B monitor line and controlled by the signal in read line RD.

Figure 13 be a diagram that the sequential chart of the operation of the circuit externally initializing node of Figure 12.In phase first stage P1 Between, use blanking voltage V0 to driving transistor T1 to be programmed, and via monitoring line OLED voltage externally set to Vrst.During second stage P2, read signal RD and make transistor T3 end, and therefore OLED voltage is put by OLED D1 Electricity, until OLED ends (creating OLED conducting voltage threshold values).During phase III P3, via monitoring line cutting OLED The only outside reading circuit of voltage transmission (such as, using charge amplifier).

Figure 14 be a diagram that the flow chart being read out pixel status by externally initializing node.In the first step In Zhou, internal node is resetted so that at least one pixel components turns on.Second step provides inner/outer node steady The fixed time to expectation state (such as, cut-off state).Third step reads the cut-off state value of internal node.

Figure 15 be a diagram that the sequential chart of the operation of the improvement of the circuit of Figure 12 (still for internally initializing node).? During first stage P1, use conducting voltage V1 to driving transistor T1 to be programmed.OLED voltage rises to than its electric conduction Pressure valve is worth higher voltage.During second stage P2, use blanking voltage V0 that driving transistor T1 is programmed, and therefore OLED voltage is discharged by OLED D1, until OLED ends (thus creating OLED conducting voltage threshold values).In the phase III During P3, by OLED conducting voltage threshold values transmission to outside reading circuit (such as, using charge amplifier).

Figure 16 be a diagram that the flow chart being read out pixel status by internally initializing node.First step Make the pixel conducting being selected for measuring so that inner/outer node is stable to conducting state.Second step makes the picture of selection Element cut-off so that inner/outer node is stable to cut-off state.Third step reads the cut-off state value of internal node.

Figure 17 be a diagram that the circuit diagram of the image element circuit shown in two Figure 12, and the two circuit is via the reading of each of which Take transistor T3 and be connected to common monitoring line, and Figure 18 be a diagram that the group for using shared monitoring line read pixel electric charge Close the sequential chart of the operation of circuit.During first stage P1, use blanking voltage V0 and V03 that pixel is programmed, and will OLED voltage is reset to VB0.During second stage P2, read signal RD cut-off, and when other signal is in cut-off state, Use conducting voltage V1 that pixel to be measured is programmed.Therefore, it is in reset shape in other pixel being connected with monitoring line During state, it is selected for the OLED voltage of pixel of measurement higher than its conducting valve threshold voltage.During phase III P3, also by Blanking voltage V02 is used to be programmed keeping it turned off to the described pixel after using conducting voltage programming.In this stage, choosing The OLED voltage of the pixel selected is discharged to its conducting valve threshold voltage.During fourth stage P4, retaking of a year or grade OLED voltage.

Figure 19 be a diagram that the flow chart of the reading with the pixel status sharing monitoring line.First step makes all pixels End and make inner/outer node reset.Second step makes the pixel conducting being selected for measuring so that inner/outer saves Point is set to conducting state.Third step makes the pixel of selection end, so that inner/outer node is stable to cut-off state. 4th step reads the cut-off state value of internal node.

Figure 20 A illustrates such image element circuit: wherein, and line Vdata (program voltage) connects via switching transistor T2 To node A, and line Monitor/Vref (Vref is reference voltage) is connected to node B via reading transistor T3.Node A connects To driving the grid of transistor T1 and being connected to store the side of capacitor Cs.Figure 20 B is the use benefit based on electric charge of Figure 20 A The sequential chart of the operation of the circuit repaid.Node B is connected to drive the source electrode of transistor T1, the opposite side of storage capacitor Cs and open Closing the drain electrode of transistor T4, described switching transistor T4 is connected between source electrode and the power voltage source Vdd of driving transistor.This Operation in the case of Zhong is as follows:

1., during programming cycle, use via transistor T2 from the program voltage V of line Vdata supply to node A_PTo picture Element is programmed, and node B is connected to the reference voltage Vref supplied from line VMonitor/Vref via transistor T3.

2. during discharge cycle, read signal RD and make transistor T3 end, and therefore voltage at node B is adjusted to Partially compensate for driving the change (such as, aging) of transistor T1.

3., during the driving stage, write signal WR makes transistor T2 end, and one section of delay (it can be zero) it After, signal EM makes transistor T4 turn on, to be connected to supply voltage Vdd drive transistor T1.Therefore, drive transistor T1's Electric current is by being stored in capacitor C_SIn Control of Voltage and identical electric current flow to OLED.

In another constructs, reference voltage Vref is provided to node A, and joint via switching transistor T2 from line Vdata Point B is supplied with via reading the program voltage Vp that transistor T3 supplies from Monitor/Vdata line.In this case operation As follows:

1., during programming cycle, node A is charged to the reference voltage supplied from line Vdata via transistor T2 Vref, and to node B supply via reading the program voltage Vp that transistor T3 supplies from line Monitor/Vref.

2. during discharge cycle, read signal RD and make transistor T3 end, and therefore voltage at node B is adjusted to Partially compensate for driving the change (or aging) of transistor T1.

3., during the driving stage, write signal WR makes transistor T2 end, and one section of delay (it can be zero) it After, signal EM makes transistor T4 turn on, to be connected to supply voltage Vdd drive transistor T1.Therefore, drive transistor T1's Electric current is by being stored in capacitor C_SIn Control of Voltage and identical electric current flow to OLED.

Figure 21 is the behaviour of the circuit of the reading for producing electric current and/or the voltage driving transistor T1 for Figure 20 A The sequential chart made.During can using or not using electric discharge, pixel is programmed.During electric discharge, then it can be Make capacitor C_SThe short time partly discharged, or it can be with long enough so that capacitor C_SElectric discharge is until driving transistor T1 Cut-off.In the case of short discharge time, driving transistor can be read by applying fixed voltage during readout time The electric current of T1, or can read by being used as by applying fixed current via reading transistor T3 from line Monitor/Vref The voltage that the driving transistor T1 of amplifier produces.In the case of long discharge time, can with retaking of a year or grade due to electric discharge at node B The voltage that place produces.This voltage represents the threshold voltage driving transistor T1.

Figure 22 is the sequential chart of the operation of the circuit of the reading for producing OLED voltage for Figure 20 A.In Figure 22 institute In the case of description, image element circuit is programmed so that driving transistor T1 to be used as (having high break-over voltage) switch, and The curtage of OLED is measured by transistor T1 and T3.In another case, at by concept transfer A and node B Voltage measures multiple current/voltage point, and can be from the voltage of formulas Extraction OLED between these electric current and voltages.Example As, if driving transistor T1 to operate in linear zone, then OLED voltage affects the electric current driving transistor T1 more；Cause This, by there is current point in driving the range of linearity of transistor T and operated in saturation district, can by the voltage of transistor T1- Current relationship extracts OLED voltage.

If two or more pixels share identical monitoring line, then by blanking voltage is applied to the most not selected for The driving transistor T1 of the pixel that OLED measures makes these pixels end.

Figure 23 is the sequential chart improving operation of the circuit of the reading producing OLED voltage for Figure 20 A, described improvement Operate as follows:

1., during reseting stage, use conducting voltage that OLED is charged.

2., during discharge regime, signal Vdata makes driving transistor T1 end, and therefore makes OLED voltage pass through OLED It is discharged to blanking voltage.

3. during the reading stage, by driving transistor T1 and reading the blanking voltage of transistor T3 retaking of a year or grade OLED.

Figure 24 illustrates the circuit for extracting parasitic capacitance from the image element circuit using external compensation.Showing for OLED Showing in most of external compensation systems of device, the internal node of pixel is being measured and is being different during drive cycle.Therefore, post The impact of raw electric capacity will not correctly be extracted.

The following is the step for parasitic parameter is compensated:

1. use one group of voltage/current (outside voltage/current or the voltage/current of inside) to measure under the first state Pixel.

2. use different one group of voltage/currents (outside voltage/current or the voltage/current of inside) to measure the second shape Pixel under state.

3., based on including the pixel model of parasitic parameter, twice measurement extracts parasitic parameter (if this model needs in the past Measure more times, then the voltage/current for difference group repeats step 2).

Another kind of technology is experimentally to extract parasitic effects.For example, it is possible to deduct two groups of measurements, and pass through gain Difference adds to other measure.This gain can experimentally be extracted.Such as, the difference after bi-directional scaling can be increased To the measurement group made for the panel of specific gray scale.Can experimentally the comparative example factor be adjusted, until panel On image up to specification.After this, this scale factor can be used as the preset parameter of other panels all.

An externally measured method of parasitic parameter is that electric current reads.In the case, for extracting parasitic parameter, permissible Measure for two groups and change the external voltage set by measuring circuit.Figure 24 shows the reading having for measuring pixel current The pixel of line.The voltage of sense line is by measuring unit bias voltage (V_B) control.

Figure 25 illustrates the image element circuit that can be used for current measurement.Use the program voltage V after calibration_calPixel is carried out Programming, and monitoring line is set as V_ref.Then, by making transistor T3 conducting measure driving transistor by control signal RD The electric current of T1.During drive cycle, the voltage at node B is in V_oled, and the voltage at node A is from V_calBecome V_cal+ (V_oled-V_ref)C_S/(C_P+C_S), here, V_calIt is the program voltage after calibration, C_PIt is the total parasitic capacitance at node A, and V_refIt is Monitoring voltage during programming.Drive the grid-source voltage V of transistor_GSDuring programming cycle and during drive cycle Being different, it is respectively (V_P-V_ref) and [(V_P-V_ref)C_S/(C_P+C_S)-V_oledC_P/(C_P+C_S)].Therefore, program and the measurement phase Between electric current due to will the parasitic capacitance that compensates of impact and different from driving electric current, if especially deposited driving in transistor T1 If significant mobility change.

In order to extract the parasitic effects during measurement, can have and in the programming cycle phase at monitoring line during measuring Between voltage (V_ref) different voltage V_B.Therefore, the grid-source voltage V during measurement_GSTo be [(V_P-V_ref)C_S/(C_P+ C_S)-V_BC_P/(C_P+C_S)].Two different V can be used_B(V_B1And V_B2) extract parasitic capacitance C_PValue.In a kind of situation Under, voltage V_PIdentical and for the electric current of two kinds of situations by difference.Pixel current formula the difference from two electric currents can be used Extract parasitic capacitance C_P.In another case, a V can be adjusted_PObtain the electricity identical with the electric current in other situation Stream.In this case, described difference will be for (V_B1-V_B2)C_P/(C_P+C_S).Accordingly, because all parameters are known, it is possible to carry Take C_P。

Figure 26 illustrates the pixel with electric charge readability.Here, internal capacitor it is charged and then will Electric charge transmits to charge integrator, or is integrated electric current by electric charge reading circuit.In the feelings that electric current is integrated Under condition, method described above can be used in extracting parasitic capacitance.

When the electric charge being integrated in internal capacitor is read in expectation, in addition to directly adjusting voltage, it is also possible to make Parasitic capacitance is extracted with two different times of integration.Such as, in the image element circuit shown in Figure 25, it is possible to use OLED electricity Hold and internally pixel current is integrated, and charge-pump amplifier then can be used externally to transmit described pixel electricity Stream.In order to extract parasitic parameter, it is possible to use method described above changes voltage.But, due to the essence of charge integration, When electric current being integrated in OLED electric capacity, it is possible to use two different times of integration.

Along with the voltage of node B increases, parasitic parameter becomes big to the impact of pixel current.Therefore, when there is longer integration Between measurement cause the bigger voltage at node B, and thus more affected by parasitic parameter.Charge value and pixel can be used public Formula extracts parasitic parameter.Other method is to guarantee to have the AVHRR NDVI electric charge of the time of integration by adjusting program voltage Identical for two kinds of situations.Then, as discussed above, it is possible to use the difference between two voltages extracts parasitic capacitance.

Compensate in the pixel based on electric charge of intelligence pixel

In fig. 26, signal and the bias voltage line of each pixel can be shared by other signal or replace and realize identical Function.The image element circuit of Figure 26 is only exemplary.And, it is possible to easily revise the position of load (such as, light emitting diode) Put.Furthermore it is possible to each TFT is changed into N-shaped TFT based on complementary circuit concept.As the image element circuit shown in Figure 26 Image element circuit compensates in using pixel based on electric charge in the following way: generate electric charge at the internal node of image element circuit (it is generally stored inside storage electric capacity C_SIn) and enable at least some in described electric charge to be removed or can as T1 and/or The function electric discharge of OLED, to allow to produce the parameter of the threshold voltage such as T1 inside image element circuit.

In fig. 26, during programming, produce at node D and compensate voltage, bias voltage is applied to node B and C also And program voltage is applied to node C.

In order to form compensation circuit, it is possible to use as shown in Figure 26 charging method illustrated by sequential chart or as by this The illustrated ground of the earlier application of application claims priority applies bias current by monitoring line like that.

The interpolation of switching transistor Tb2 eliminates less desirable luminescence during programming/compensation cycle, because it makes electric current It is diverted through Vb2.

This circuit also allows for read pixel or OLED current/voltage as is described elsewhere herein.

This pixel can also read TFT or OLED current, voltage or electric charge by Tm.

TFT is read, it is possible to use pixel is programmed by predefined parameter (or the voltage calculated), then makes Tm Conducting.Here, owing to Tem turns on, so the voltage of monitoring line is smaller than OLED voltage.This will ensure that OLED ends.At this moment, Can read pixel electric current.Other method: WR and RD conducting and EM cut-off, and curtage is applied to monitoring line and returns Read current or voltage.And, apply to monitoring line curtage can be include zero any value.

In order to read OLED (curtage), pixel can be programmed, so that driving TFT to be used as switch (such as, Vb1 can be adjusted, so that Td is changed into switch).It is then possible to read OLED current or voltage by monitoring line.

For the another kind of reading to OLED current or voltage, EM signal can end, hence without electric current by Td, and because of This can read OLED current or voltage.

For the another kind of reading to OLED current or voltage, V can be become during programming cycle with node D_OLED's Mode selects Vb1.Then, after TFT programs, can be with the impact on TFT of the retaking of a year or grade OLED voltage.

In figure 27, such as, EM signal is divided into two signals.This allows to use Tb to make node D reset, with based on such as Voltage is generated and compensates by the charge/discharge function described by the waveform in Figure 27.It can be seen that EM ' can be next line EM signal.

This pixel can also read TFT or OLED current, voltage or electric charge by Tm.

TFT is read, it is possible to use pixel is programmed by predefined parameter (or the voltage calculated), then makes Tm Conducting.Here, owing to Tem turns on, so the voltage of monitoring line is smaller than OLED voltage.This will ensure that OLED ends.At this moment, Can be with read pixel electric current.Other method: WR and RD conducting and EM cut-off, and curtage is applied to monitoring line and returns Read current or voltage.And, apply to monitoring line curtage can be include zero any value.

For reading OLED current or voltage, pixel can be programmed so that drive TFT be used as switch (for example, it is possible to Vb1 is adjusted, so that Td is changed into switch).It is then possible to read OLED current or voltage by monitoring line.

For the another kind of reading to OLED current or voltage, EM ' signal can end, hence without electric current by Td, and Therefore OLED current or voltage can be read.

For the another kind of reading to OLED current or voltage, V can be become during programming cycle by node D_OLED Mode select Vb1.Then, after TFT programs, can be with the impact on TFT of the retaking of a year or grade OLED voltage.

In Figure 28, such as, EM signal is divided into two signals.This allows to use Tb to make node D reset, with based on such as Voltage is generated and compensates by the charge/discharge function described by the waveform in Figure 28.And, Tm and Tb2 is shared.

It can be seen that EM ' can be the EM signal of next line.

This image element circuit 104 also allows for being read or extract TFT or OLED current, voltage or electric charge by Tm.

For driving TFT curtage to read, it is possible to use pixel is entered by predefined parameter (or the voltage calculated) Row programming, then makes Tm turn on.In this example, owing to Tem turns on, so the voltage of monitoring line is smaller than OLED voltage.This Will ensure that OLED ends.At this moment, it is possible to read pixel electric current.Alternately, WR and RD conducting and EM cut-off, and by electric current or Voltage applies to monitoring line and retaking of a year or grade curtage.And, the curtage applying extremely monitoring line can be to include zero Any value.

For reading OLED (current/voltage/electric charge), pixel can be programmed so that TFT provides zero current.Then, OLED current or voltage can be read by monitoring line.

For the another kind of reading to OLED current or voltage, EM ' signal can end, hence without electric current by Td, and Therefore OLED current or voltage can be read.

For the another kind of reading to OLED current or voltage, V can be become during programming cycle by node D_OLED Mode select Vb1.Then, after TFT programs, can be with the impact on TFT of the retaking of a year or grade OLED voltage.

For the circuit shown in Figure 29, during programming, while EM ends, make node B multiple by Tm and monitoring line Position and node C is charged to Vdata.In compensation cycle (cycle 4) period, use and drive TFT (Td) to charge to node B make Compensation voltage for the function of Td characteristic.In drive cycle (6) period, EM turns on, and the grid of therefore Td is by being stored in C_SIn Program voltage and compensate limiting voltage.

This pixel can also read TFT or OLED current, voltage or electric charge by Tm.

For driving the reading of TFT curtage, it is possible to use predefined parameter (or the voltage calculated) is to pixel It is programmed, then makes Tm turn on.Here, owing to Tem turns on, so the voltage of monitoring line is smaller than OLED voltage.This will be really Protect OLED cut-off.At this moment, can be with read pixel electric current.Alternately, WR and RD conducting and EM cut-off, and by electric current or electricity Pressure applies to monitoring line and retaking of a year or grade curtage.Additionally, apply to the curtage of monitoring line to include zero Any value.

For reading OLED current or voltage, pixel can be programmed so that TFT provides zero current.Then, EM conducting And OLED current or voltage can be read by monitoring line.

Programming and driving

In a structure of the compensation pixel circuit based on electric charge shown in Figure 30, the line being connected with T2 is data voltage And the line being connected with T3 is Monitor/Vref voltage.Operation in this example can carry out as follows:

During the period 1, use program voltage (VP) that pixel is programmed, and node B is connected to reference to electricity Pressure.

During second round, RD signal end, and partly adjust node B place voltage with to T1 change (or Aging) compensate.

During the phase III, WR signal ends, and after one section of delay (it can be zero), EM turns on.Therefore, T1 Electric current be stored in C_SIn Control of Voltage and identical current direction OLED.

In another constructs, the line being connected with T2 is reference voltage (Vref) and the line that is connected with T3 is Monitor/ Vdata line.

During the period 1, node A is charged to reference voltage, and node B is connected to program voltage (VP).

During second round, RD signal end, and partly adjust node B place voltage with to T1 change (or Aging) compensate.

During the phase III, WR signal ends, and after one section of delay (it can be zero), EM turns on.Therefore, T1 Electric current be stored in C_SIn Control of Voltage and identical current direction OLED.

TFT is driven to read

For the reading of the curtage of the driving T1 shown in Figure 31, pixel is entered by (use or do not use the electric discharge period) Row programming.If there is the electric discharge period, then it can be to make capacitor C_SThe relatively short time partly discharged, or it can To grow to make capacitor C_SElectric discharge is until driving T1 cut-off.In the case of short discharge time, can be by phase readout time Between apply to fix reference voltage read the electric current driving T1, or can read by applying fixing electric current via T3 The voltage produced by the driving T1 as amplifier.In the case of long discharge time, can with retaking of a year or grade caused by discharging The voltage produced at node B.This voltage will represent the threshold voltage of T1.

And, during whole, WR signal can be held on.

OLED reads

In the image element circuit shown in Figure 32, it is programmed T1 serving as (there is high break-over voltage) switch. Furthermore, it is possible to measured or extract the curtage of OLED by T3 and T1.

In another example, measure several current/voltage point by the voltage at concept transfer A and node B1, and Can be from the voltage of formulas Extraction OLED between these electric current and voltages.Such as, if T1 is in its linear zone, then OLED Voltage can affect the electric current of T1 more；Therefore, by there is current point, Ke Yicong in the linear of T and operated in saturation district The voltage-current relation of T1 extracts OLED voltage.

If several pixels share identical monitoring line, then will be by blanking voltage applying is made not selected use to T1 In the pixel cut-off that OLED measures.

In the image element circuit shown in Figure 33, the reading of the curtage of OLED can be carried out as follows:

During reseting stage, use conducting voltage that OLED is charged.

Drive T1 cut-off, and therefore make OLED voltage be discharged to blanking voltage by OLED.

By T1 retaking of a year or grade blanking voltage.

In aforementioned image element circuit, can using the inverse signal of RD or WR as EM signal (so EM signal can corresponding to/ RD or/WR).In this case, it is possible to make signal invert and be passed to pixel, or complementary type TFT can be used to produce Raw inverse function.Such as, if PMOS switch to be used for RD TFT, then nmos switch can be used for EM TFT.

Furthermore, it is possible to use the reverse signal of next RD or WR signal (or previous RD signal) to replace as current line EM signal.It is likewise possible to outside image element circuit, realize the inverse function of RD and WR and be passed to image element circuit, or can To use the combination of complementary type TFT.

Figure 34 illustrates the other method realizing luminous EM function in image element circuit 104 based on electric charge.Here it is possible to The reversion using control signal RD and WR produces luminous EM signal.Therefore, if either of which person's conducting, then pixel is electric Road will disconnect with power vd D.It is likewise possible to realize outside image element circuit 104 RD and WR inverse function (/RD and/WR) and It is passed to image element circuit, or complementary type TFT can be used to combine.Although NMOS TFT can be used for T4 and T5, but pushes away Recommend (but not necessarily) PMOS is used for these TFT and NMOS is used for WR and RD (such as, S2 and S3).

Image element circuit 104 in Figure 34 include the driving transistor T1 that is connected with light-emitting device (OLED) and with drive crystalline substance Body pipe T1 connects and stores the storage device (C of programming information_S), so that OLED is luminous according to the programming information via T1.C_S Can (rather than must) be directly connected between the grid of T1 and the first terminal (source electrode or drain electrode, this depend on T1 be NMOS also It is PMOS).Second terminal (another one in source electrode or drain electrode) of T1 can be connected to OLED.

The image element circuit 104 of Figure 34 includes the first switch S2, and described first switch S2 is connected to T1, and (it can with First Line Transmit programming information Vdata or reference voltage Vref) between T1 is connected to First Line according to the first signal (such as, WR). Image element circuit 104 includes that second switch S3, described second switch S3 are connected between T1 and the second line with according to secondary signal (example As, RD) the second line (it at least has two functions) is connected to T1.Second line can be used as monitoring line, with monitoring from pixel electricity The curtage that one or more assemblies on road read.Second line can be additionally used in reference voltage Vref or programming information Vdata provides the internal node B to image element circuit.

The image element circuit 104 of Figure 34 includes the 3rd switch (S4) and the 4th being connected in the line between T1 and power supply Vdd Switch (S5).The control signal of the 3rd switch (S4) and the 4th switch (S5) and each of which has the first switch S2 and second The inverse function of the control signal of switch S3 and each of which.This means that S2 and S3 can be n-type transistor, and S4 and S5 is P-type transistor.Or, S2 and S3 can be p-type transistor, and S4 and S5 is n-type transistor.Or, S2 to S5 can be phase The transistor of same type (N-shaped or p-type), but S4 and S5 is controlled by the signal of the reversion as the signal controlling S2 or S3.Example Can be controlled by/WR or/RD such as, S4 and S5 can be controlled by/RD or/WR, and S2 by WR control and S3 by RD control.Or, permissible The single switch using the control signal with its own replaces two switch S4 and S5.In other words, described inverse function is phase Opposite state.Such as, when the first and second switch conductions or controlled by respective control signal and when turning on, then the third and fourth switch End or controlled by respective control signal and end.

In this example, it is only necessary to minimum two control signals RD and WR (and can directly derive from RD and WR respectively Their inverse signal), to realize compensating in pixel and outside by reading image element circuit curtage via the second line Compensate.When the first switch S2 is closed, program voltage (Vdata) or reference voltage (Vref) can be provided to storage by First Line Device C_S。

For the skew of internally compensating parameter (threshold voltage of similar T1), First Line is by the S2 (WR is effective) of Guan Bi Apply Vref, so that internal node B is charged to Vref.Make C_SIn storage electric charge discharge within the electric discharge period, until electric charge Represent the threshold voltage of at least T1.Make WR invalid, now, C_S(it is T1 to the function becoming Vdata Vdischarge at two ends Function with OLED).

In order to from the assembly of image element circuit (such as, T1 or OLED, or both) read current or voltage, make RD effectively with Closing S3, this allows to read curtage (monitoring function) from the second line.During programming cycle, when S3 is closed, the Two wires also can be used to provide to S3 Vdata.In this way, it is possible to by using the second line drawing circuit parameter and by circuit Parameter store to image element circuit outside outside image element circuit to the change of image element circuit or aging compensate.Described circuit Parameter can be at least To or at least OLED or the curtage of at least T1 and OLED.

Note, in the image element circuit of Figure 34, can be from First Line or the second line (but not being) supply reference voltage simultaneously Vref.The electric charge being associated with the Vref of supply is maintained at C_SIn.Likewise it is possible to from First Line or the second line (but be not Supply program voltage Vdata, and Vdata simultaneously) is at least initially kept at C_SIn.OLED is according in the Vdata at least stored A part and luminous.Can increase from program voltage or deduct and interiorly or exteriorly compensate.This motility allows in pel array Multiple row between share one line or two lines.Control signal RD and WR also can be total between multiple row of image element circuit With.

Figure 34 further relates to extract circuit parameter and for mending in the difference of image element circuit or aging offer pixel from image element circuit The method repaid.Described method includes: by being applied to image element circuit by reference voltage (Vref) from First Line or the second line Storage device (C_S) with based on reference voltage (Vref) to storage device (C_S) be charged, cause in image element circuit Driving means (T1) or light-emitting device (OLED) or the difference of both or aging carry out self-compensating pixel in compensate.Described side Method includes: by closing the switch (S2 or S3) in described image element circuit to allow to join from First Line or the second line reading circuit Number (such as, flow through the curtage of T1, OLED or T1 and OLED), uses the circuit outside image element circuit to carry from image element circuit Sense circuit parameter.Described method includes: it follows that use the programming information that the circuit parameter having been based at least extracting is compensated (such as, deriving from Vdata) drives image element circuit.When image element circuit is all disconnected with First Line and the second line and even When two switches (S4 and S5) being connected in the line between driving means (T1) and power supply (VDD) are all closed, perform to drive week Phase.

Common switch between multiple row and/or multiple row

Figure 35 shows the image element circuit of prior art.In operation, during programming, EM cut-off and WR conducting.

Apply a current to pixel by Iref and program voltage (VP) is applied to Vdata.At node A and node B Produce the bias voltage (VB) of the function as Iref and T1 characteristic.C_SIn storage voltage be VP-VB.

During driving/light period: luminous circulation EM conducting and write signal WR cut-off.Node C is from program voltage VP Become supply voltage VDD.Node A carries out booting (boot-strap) and moving with identical value (VDD-VP) by capacitor CS Dynamic.Therefore, the voltage at node A will be VB+VDD-VP.During this cycle, the electric current proportional for VP compensated to use VB Driving transistor T1 and OLED will be flowed through.

The now operation to the image element circuit shown in Figure 36 illustrates.Switch can be shared between each row and each row. Tc and Td can be shared by each row.Ta and Tb can be shared by row and column.

If only row occur to share, then SEM with SWR can be identical with EM and WR.

If also occurring row to share, then SEM and SWR is used as overall signal.

During the programming to the row being connected with identical SEM and SWR, SEM cut-off and SWR conducting.Driving at these row During dynamic/luminescence, SEM conducting and SWR cut-off.

Shared condition in Figure 37 is identical with the image element circuit in Figure 36, but programming cycle is different.In programming cycle, SEM/EM cut-off and SWR/WR conducting.When starting, node B and A is reset to Vref by RD conducting.Hereafter, RD ends, and uses Node B and A is charged by T1.Charge volume is the function of T1 parameter.Therefore, at node A development voltage be the function of T1 also During driving/light period, its heterogeneity/aging will be compensated.

The operation of the image element circuit in Figure 36 is identical with Figure 37 with shared principle.

Figure 38 shows the 3 transistor pixels circuit that can use compensation based on electric charge.Vdata includes program voltage, and Vref provides reference voltage via T3.Control signal RD and WR control T3 and T2 respectively for each image element circuit, and SEM and SWR control signal is overall.SWR is shared between each row, and SEM can be shared between each row/each row.

Figure 39 A to Figure 49 B shows the change (such as, aging and processing heterogeneity) for the parameter to image element circuit The various image element circuits compensated and corresponding sequential chart.It will be appreciated by one of skill in the art that how to connect shown in the drawings respectively Plant assembly.The labelling used is consistent with the labelling that text of the statement uses.T1 is typically used for basis and is stored in capacitor C_S In the electric current that matches of electric charge drive the driving transistor of OLED.This electric charge maybe can not drive the threshold values of transistor T1 to picture The such impact of the skew of voltage carries out self compensation.Other transistor is marked as T2, T3 and T4 etc..Control signal is labeled, Wherein RD=reads, and WR=write and EM=are luminous.EM signal controls whether to make OLED turn on to carry out luminescence.Vdd is power supply Voltage.Vdata is the holding wire of the programming information of the voltage form of transmission correspondence, and described programming information can or can not be externally The change of one or more parameters of compensation pixel circuit.The line being marked as Monitor is for from image element circuit (such as, From both T1, OLED or T1 and OLED) read or extract the holding wire of curtage.Extract from outside use of image element circuit Described curtage (all to the change of the parameter including the skew of T1 or OLED or the threshold voltage of both As aging) compensate.In sequential chart, " programming " refers to that programming information (in the form of voltage or current) is applied to Vdata Line is also stored in C_SIn programming cycle." discharge " is to instigate to be stored in C_SIn electric discharge phase of discharging at least in part of electric charge Between.Interior during electric discharge at this, C_SFinal voltage generally settle out at the value of threshold voltage representing T1, and be used to pin The skew of the threshold voltage of T1 is carried out internally self compensation to the program voltage applied.Finally, " drive scheme " refers to OLED is connected to supply voltage VDD and electric current according to being stored in C_SIn residual charge flow to the luminescence of OLED." programming/mend Repay " refer to programming and interiorly or exteriorly compensate the mixing cycle that all can occur.Preferably but not necessarily, inside is first carried out Compensate, then carry out external compensation.But, each aspect of the present invention is not limited to any particular order external compensation can be prior to Internal compensation.RESET operation is to instigate image element circuit (such as, to be stored in C_SIn electric charge) reset." read " operation to refer to lead to Cross use monitoring line read from image element circuit (such as, T1, OLED or T1 and OLED both) or extract curtage.

Described herein and show much the most not only for internal compensation but also for the different embodiments of external compensation.Ying Qing Chu ground understands, can use any combination of any image element circuit and any sequential chart in this article.Described herein is any Image element circuit can work with other sequential any shown in other accompanying drawing any and operation cycle, and any sequential and operation Cycle can be used or modified to operate together with any image element circuit described herein.Owing to those skilled in the art can Any suitable voltage level or sequential persistent period is selected to realize any specific embodiment, so all of voltage level, Formula and sequential persistent period are the most only exemplary and be not restrictive.

Although having illustrated and illustrated only certain embodiments of the present invention and application, but it is to be understood that the present invention does not limits In accurate structure described herein and composition, and without departing from such as this of restriction in appended claims of the invention In the case of bright spirit and scope, the various amendments of the present invention, change and change and be apparent from from explanation above.

Claims (17)

1. there is an image element circuit for light-emitting device, comprising:

Driving transistor, it is connected to described light-emitting device；

Storage device, it is connected to described driving transistor and stores programming information, so that described light-emitting device is according to via institute State and drive the described programming information of transistor and luminous；

First switch, it is connected between described driving transistor AND gate First Line, with according to the first signal by described driving crystal Pipe is connected to described First Line；

Second switch, it is connected between described driving transistor AND gate the second line, with according to secondary signal by described second line even It is connected to described driving transistor；And

3rd switch and the 4th switchs, and it is connected in the line between described driving transistor AND gate power supply, and the described 3rd opens Close and described 4th switch and the control signal of each of which have described first switch and described second switch and they The inverse function of respective control signal.

2. image element circuit as claimed in claim 1, wherein, described 3rd switch is by described first signal control and the described 4th Switch is controlled by described secondary signal, or, described 3rd switch is by the inverse signal control and the described 4th of described first signal Switch and controlled by the inverse signal of described secondary signal, or, described 3rd switch is controlled by described secondary signal and the described 4th Switch and controlled by described first signal, or, described 3rd switch is by the inverse signal control and the described 4th of described secondary signal Switch and controlled by the inverse signal of described first signal.

3. image element circuit as claimed in claim 1, wherein, described first switch and described second switch be n-type transistor and Described 3rd switch and described 4th switch are p-type transistor, or, described first switch and described second switch are that p-type is brilliant Body pipe and described 3rd switch and described 4th switch are n-type transistor so that when described first switch and described second switch During conducting, described 3rd switch and described 4th switch cut-off, and when described first switch and described second switch end, Described 3rd switch and described 4th switch conduction.

4. image element circuit as claimed in claim 1, wherein, described first switch, described second switch, the described 3rd switch and Described 4th switch is only controlled by described first signal and described secondary signal and is not had other signal.

5. image element circuit as claimed in claim 1, wherein, when described first switch is closed, described First Line will programming Voltage or reference voltage supplies are to described storage device.

6. image element circuit as claimed in claim 5, wherein, applies described reference voltage with according to described ginseng from described First Line Examine voltage described storage device is charged, and make the electric charge being stored in described storage device put by described driving transistor Electricity, so that the voltage at described storage device two ends is at least the function of the threshold voltage of described driving transistor.

7. image element circuit as claimed in claim 1, wherein, when described second switch is closed, described second line is used to From described image element circuit read voltage or electric current, or by reference voltage supplies to described image element circuit.

8. image element circuit as claimed in claim 1, wherein, when described second switch is closed, described second line is used to From described image element circuit read voltage or electric current, or by program voltage supply to described image element circuit.

9. image element circuit as claimed in claim 1, wherein, described storage device is capacitor and drives described in being directly connected between Between grid and the first terminal of dynamic transistor.

10. image element circuit as claimed in claim 9, wherein, the second terminal of described driving transistor is connected to described luminescence Device.

11. image element circuits as claimed in claim 1, wherein, by charging to the node being connected with described driving transistor Reference voltage also represents the institute of described driving transistor via the electric discharge of described driving transistor with storage in described storage device Stating the electric charge of threshold voltage, described image element circuit internally compensates the change of the threshold voltage of described driving transistor.

12. image element circuits as claimed in claim 11, wherein, by using described second line drawing circuit parameter and by described Circuit parameter stores to described image element circuit, for the change or aging outside described image element circuit of described image element circuit Described image element circuit is compensated.

13. image element circuits as claimed in claim 12, wherein, described circuit parameter is the electric current of the most described driving transistor Or voltage, or the curtage of the most described light-emitting device, or the most described driving transistor and described light-emitting device Curtage.

14. image element circuits as claimed in claim 1, wherein, described first switch and described second switch are disposed in described In image element circuit so that from described First Line or from described second line supply reference voltage rather than simultaneously from described First Line With described second line supply reference voltage, described storage device is charged by described reference voltage so that it keeps and described ginseng Examine the electric charge that voltage matches.

15. image element circuits as claimed in claim 1, wherein, described first switch and described second switch are disposed in described In image element circuit so that from described First Line or from described second line supply program voltage rather than simultaneously from described First Line With described second line supply program voltage, described program voltage is stored in described storage device so that described program voltage In be used at least partially make described light-emitting device according in described program voltage described at least some of and luminous.

16. image element circuits as claimed in claim 1, wherein, described inverse function is inverse state so that when described first switchs When controlling with the conducting of described second switch or controlled signal and turn on, described 3rd switch and described 4th switch cut-off or quilt Described control signal controls and ends.

Described image element circuit from image element circuit extraction circuit parameter and is changed or compensation in aging offer pixel by 17. 1 kinds Method, described image element circuit includes light-emitting device, for programmable drive current provides the driving dress to described light-emitting device Putting, program input and for storing the storage device of programming signal, described method includes:

By the storage device that reference voltage applied to image element circuit from First Line or the second line with based on described with reference to electricity Described storage device is charged by pressure, causes generation for the described driving means in described image element circuit or described luminescence Device or the change of both or aging carry out self-compensating pixel in compensate；

By closing the switch in described image element circuit to allow to read described electricity from described First Line or from described second line LUSHEN number, uses the circuit outside described image element circuit to extract described circuit parameter from described image element circuit；And

Subsequently, have been at the programming information after compensating based on the described circuit parameter extracted by use and drive described Image element circuit, wherein, when described image element circuit is all disconnected with described First Line and described second line and in place being connected When two switches in line between described driving means and power supply are closed, perform described driving.