CN111048044B - Voltage programming type AMOLED pixel driving circuit and driving method thereof - Google Patents

Voltage programming type AMOLED pixel driving circuit and driving method thereof Download PDF

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CN111048044B
CN111048044B CN201911409174.2A CN201911409174A CN111048044B CN 111048044 B CN111048044 B CN 111048044B CN 201911409174 A CN201911409174 A CN 201911409174A CN 111048044 B CN111048044 B CN 111048044B
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transistor
scanning signal
node
light emitting
data input
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CN111048044A (en
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何红宇
张立文
关肖飞
曾涌韬
李月华
王新林
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University of South China
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3225—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix

Abstract

The pixel circuit comprises a driving module, a zero clearing module, a data input module and a light emitting module. The driving module comprises a first transistor and a second transistor, the zero clearing module is composed of a third transistor, the data input module comprises a fourth transistor, a first capacitor and a second capacitor, the light emitting module comprises a fifth transistor and an organic light emitting diode, and the driving module controls the state and the voltage compensation of the transistors under the action of data extraction and input to enable the light emitting module to emit light. The light emitting element is driven by setting the first to third scan signals, the control signal terminal, and the data input signal as different inputs in the initialization stage S1, the data extraction stage S2, the data input stage S3, and the light emitting stage S4 of the pixel circuit, respectively. The invention has simple circuit structure and convenient control, can compensate the threshold voltage drift, the mobility change and the circuit voltage drop of the transistor, improves the display quality and prolongs the service life of the light-emitting element.

Description

Voltage programming type AMOLED pixel driving circuit and driving method thereof
Technical Field
The invention relates to the technical field of display, in particular to a voltage programming type AMOLED pixel driving circuit capable of compensating device threshold voltage change and power voltage drop and a driving method thereof.
Background
Active-matrix Organic Light Emitting Diode (AMOLED) displays are attempting to expand their range of applications, from small mobile displays to large televisions. Compared with a traditional thin film transistor Display (Liquid Crystal Display), the AMOLED is widely used due to its advantages of high contrast, fast response time, high resolution, low power consumption, high brightness, and the like.
However, the electron-optical characteristics of the Thin Film Transistor (TFT), which is the core device of the AMOLED display screen, are relatively sensitive. The optoelectronic characteristics such as the threshold voltage of the driving transistor are easily shifted in the crystallization process. These variations can directly lead to non-uniformity in the emission of the OLED.
The traditional pixel circuit consists of two transistors and a capacitor, but the variation of the threshold voltage of the driving transistor can cause the unstable phenomenon of the driving current generated by the driving transistor, thereby greatly influencing the uniformity of the luminous brightness of the organic light-emitting diode OLED. On the basis, in order to solve the problem of the change of the threshold voltage of the driving transistor, a plurality of novel pixel circuits are designed, and a plurality of compensation methods are provided, however, the structures of the circuits are generally complex, and the compensation effect is not ideal enough.
The traditional design method for compensating the parameter change of the driving transistor by using the compensation circuit has the problem of insufficient compensation capability, usually only can realize the compensation of the threshold voltage change of the driving transistor, but has less compensation circuits for the mobility and the voltage drop, and the aperture ratio of the panel is reduced by more control lines, so that the light transmittance is reduced, and the light emitting brightness of the display is greatly influenced. As the demand for high resolution and large size increases in modern display technology, pixel circuits for solving the above problems are urgently required to be provided.
Disclosure of Invention
The present invention is directed to overcome the above-mentioned deficiencies of the prior art and provide a voltage programming type AMOLED pixel driving circuit and a driving method thereof, which can compensate the voltage drop caused by the threshold voltage, mobility and parasitic resistance of the driving transistor, avoid the flicker of the OLED in the non-light emitting stage, reduce the wiring complexity in the circuit, effectively increase the programming speed of the pixel circuit, and is suitable for the requirements of large-size and high-resolution display panels.
The technical scheme of the invention is as follows: the voltage programming type AMOLED pixel driving circuit comprises a driving module, a zero clearing module, a data input module and a light emitting module.
The driving module comprises a first transistor and a second transistor, wherein the first transistor is controlled by a first scanning signal and is used for forming a diode connection state with the second transistor and modulating the voltage of a first node, and the second transistor is controlled by a second scanning signal and is used for forming a diode connection state with the first transistor and generating a voltage increment.
The first transistor and the second transistor are both P-type low-temperature polycrystalline silicon thin film transistors, the grid electrode of the first transistor is connected with a first node, the source electrode of the first transistor is connected with a first scanning signal, and the drain electrode of the first transistor is connected with the light emitting module; the gate of the second transistor is connected to the second scan signal, the source is connected to the first node, and the drain is connected to the drain of the first transistor.
The zero clearing module is composed of a third transistor, is respectively connected with the first scanning signal, the grounding terminal and the data input module, and is used for clearing the charges left in the first capacitor and the second capacitor after the previous period is finished under the control of the first scanning signal so as to realize initialization.
The third transistor is a P-type low-temperature polysilicon thin film transistor, the grid electrode of the third transistor is connected with a first scanning signal, the source electrode of the third transistor is connected with a grounding end, and the drain electrode of the third transistor is connected with a first node.
The data input module comprises a fourth transistor, a first capacitor and a second capacitor, wherein the fourth transistor is controlled by a third scanning signal and is used for inputting the voltage variation of the data input signal input to the second node and coupling the voltage variation to the first node through the first capacitor and the second capacitor.
The fourth transistor is a P-type low-temperature polycrystalline silicon thin film transistor, the grid electrode of the fourth transistor is connected with a third scanning signal, the source electrode of the fourth transistor is connected with a data input signal, and the drain electrode of the fourth transistor is connected with a second node; the first capacitor is arranged between the first node and the second node, and the second capacitor is arranged between the first node and the grounding terminal.
The light emitting module comprises a fifth transistor and an organic light emitting diode, wherein the fifth transistor is controlled by the control signal end and is used for controlling the light emitting of the organic light emitting diode.
The fifth transistor is a P-type low-temperature polycrystalline silicon thin film transistor, the grid electrode of the fifth transistor is connected with the control signal end, the source electrode of the fifth transistor is connected with the driving module, the drain electrode of the fifth transistor is connected with the anode of the light-emitting element, and the cathode of the light-emitting element is connected with the negative power supply end.
The invention provides a driving method applied to the voltage programming type AMOLED pixel driving circuit, which comprises the following steps,
A. initialization stage S1: and the first scanning signal and the third scanning signal are input with low level, the second scanning signal, the control signal end and the data input signal are input with high level, the third transistor and the fourth transistor are switched on, and the first transistor, the second transistor and the fifth transistor are switched off.
B. Data extraction stage S2: the first scanning signal, the control signal end and the data input signal are all input with high level, the third scanning signal and the second scanning signal are input with low level, the fourth transistor and the second transistor are conducted, and the third transistor and the fifth transistor are cut off.
C. Data input stage S3: the first scanning signal, the third scanning signal and the control signal end input high level, the data input signal inputs low level, the fourth transistor is conducted, the third transistor and the fifth transistor are cut off, the low level is input in the second scanning signal initial time T, the low level is changed into the input high level after the time T, and the time T of the second scanning signal input low level is less than the time sequence period.
D. Lighting phase S4: the first scanning signal, the third scanning signal and the second scanning signal are input with high level, the control signal end is input with low level, the fifth transistor is switched on, and the second transistor, the third transistor and the fourth transistor are switched off.
The further technical scheme of the invention is as follows: the range of the time T for inputting the low level of the second scanning signal is 0 < T < 1.5 mus.
Compared with the prior art, the invention has the following characteristics:
1. the pixel circuit has the advantages of simple structure, simple driving time sequence period, higher aperture opening ratio and simpler driving mode, compensates the threshold voltage and the mobility of the driving transistor, and compensates the voltage drop caused by parasitic resistance, so that the display brightness is more uniform.
2. The pixel circuit of the invention has no current flowing through the light-emitting element in the non-working state, thereby avoiding the light-emitting element from shining and flickering in the non-working state, prolonging the service life of the light-emitting element, reducing the power consumption of the circuit, avoiding the contrast reduction of a large-area panel and improving the contrast of the display panel.
The detailed structure of the present invention will be further described with reference to the accompanying drawings and the detailed description.
Drawings
FIG. 1 is a schematic diagram of a pixel circuit according to the present invention;
FIG. 2 is a timing diagram of the pixel circuit of FIG. 1;
FIG. 3 is a simulation plot of the first node A voltage and the first transistor threshold voltage shift;
FIG. 4 shows the driving current IOLEDA simulated plot of the threshold voltage drift associated with the first transistor;
FIG. 5 shows the driving current IOLEDA simulation plot of mobility variation versus the first transistor;
FIG. 6 shows the driving current IOLEDAnd a simulation diagram of the voltage drop change of the circuit parasitic resistance.
Detailed Description
In a first embodiment, as shown in fig. 1-2, a voltage-programmed AMOLED pixel driving circuit includes a driving module 11, a clearing module 12, a data input module 13, and a light emitting module 14.
The driving module 11 includes a first transistor T1 and a second transistor T2. The first transistor T1 is controlled by a first Scan signal Scan1 to form a diode-connected state with the second transistor T2 to modulate the voltage of the first node a, and the second transistor T2 is controlled by a second Scan signal Scan2 to form a diode-connected state with the first transistor T1 and generate a voltage increment.
The first transistor T1 and the second transistor T2 are both P-type low temperature polysilicon thin film transistors LTPS-TFT, the gate of the first transistor T1 is connected to the first node a, the source is connected to the first Scan signal Scan1, and the drain is connected to the light emitting module 14; the second transistor T2 has a gate connected to the second Scan signal Scan2, a source connected to the first node a, and a drain connected to the drain of the first transistor T1.
The zero clearing module 12 is composed of a third transistor T3, and is respectively connected to the first Scan signal Scan1, the ground terminal, and the data input module 13. The reset circuit is used for clearing the charges left in the first capacitor C1 and the second capacitor C2 after the previous period is finished under the control of the first Scan signal Scan1, so as to realize initialization.
The third transistor T3 is a P-type low temperature polysilicon thin film transistor LTPS-TFT, the gate of which is connected to the first Scan signal Scan1, the source of which is connected to the ground, and the drain of which is connected to the first node a.
The data input block 13 includes a fourth transistor T4, a first capacitor C1, and a second capacitor C2, and the fourth transistor T4 is controlled by a third Scan signal Scan3, and is used to input a voltage variation amount of the data input signal Vdata input to the second node B and coupled to the first node a through the first capacitor C1 and the second capacitor C2. Specifically, the fourth transistor T4 is a P-type low temperature polysilicon thin film transistor LTPS-TFT, the gate of which is connected to the third Scan signal Scan3, the source of which is connected to the data input signal Vdata, and the drain of which is connected to the second node B; the first capacitor C1 is disposed between the first node a and the second node B, and the second capacitor C2 is disposed between the first node a and ground.
The light emitting module 14 includes a fifth transistor T5 and an organic light emitting diode OLED. The fifth transistor T5 is controlled by the control signal terminal EN and is used for controlling the light emission of the organic light emitting diode OLED. The fifth transistor T5 is a P-type low temperature polysilicon thin film transistor LTPS-TFT, having a gate connected to the control signal terminal EN, a source connected to the driving module 11, a drain connected to the anode of the light emitting element, and a cathode connected to the negative power source terminal VSS.
As shown in fig. 2, the driving method applied to the voltage programming AMOLED pixel driving circuit in the first embodiment includes the following stages:
A. initialization stage S1: when the first Scan signal Scan1 and the third Scan signal Scan3 are inputted with a low level, and the second Scan signal Scan2, the control signal terminal EN, and the data input signal Vdata are inputted with a high level, the third transistor T3 and the fourth transistor are turned on, and the first transistor T1, the second transistor T2, and the fifth transistor T5 are turned off. The data input signal Vdata is input with a high level of 0V, and the voltages of the two points of the first capacitor C1 and the second capacitor C2 are both 0V, so that the charges left in the two capacitors at the previous stage are cleared. Since the voltage difference between the gate and the source of the first transistor T1 is 0V, the first transistor T1 is turned off. In the S1 stage, the organic light emitting diode OLED does not emit light because the fifth transistor T5 is turned off and no driving current is generated.
B. Data extractionTaking stage S2: the first Scan signal Scan1, the control signal terminal EN, and the data input signal Vdata are all inputted with a high level, the third Scan signal Scan3 and the second Scan signal Scan2 are inputted with a low level, the fourth transistor T4 and the second transistor T2 are turned on, and the third transistor T3 and the fifth transistor T5 are turned off. The transistor T2 is in conduction state, the gate and drain of the transistor T1 are connected, the data input signal Vdata is kept unchanged and continuously input with high level V data_H0V, the voltage of the second node B is initially 0V at this stage, and the difference between the potential of the first node A in the gate and the voltage of the first Scan signal Scan1 connected to the source is greater than the threshold voltage V of the first transistor T1TH_T1Therefore, the first transistor T1 is in the diode connection state, and due to the diode connection characteristic, the potential of the first node a gradually rises until the voltage of the first node a is kept unchanged after the first transistor T1 reaches the saturation critical state, and the voltage value of the first node a becomes:
VA＝Vscan1-|VTH_T1| (1)
in this S2 stage, since the fifth transistor T5 is turned off and no driving current is generated, the organic light emitting diode OLED does not emit light.
C. Data input stage S3: the first Scan signal Scan1, the third Scan signal Scan3, and the control signal terminal EN are inputted with a high level, and the data input signal Vdata is inputted with a low level Vdata_Lat-3.5V, the fourth transistor T4 is turned on, and the third transistor T3 and the fifth transistor T5 are turned off. When the data input signal Vdata changes from high level to low level, the voltage change is Δ V, and the voltage change time t of the data input signal Vdata is t0Under the coupling effect of the first capacitor C1 and the second capacitor C2, the voltage at the first node a becomes:
Figure BDA0002349514260000071
wherein
ΔV＝Vdata_L-Vdata_H (3)
The absolute value of the gate-source voltage difference at this time is:
Figure BDA0002349514260000072
the second Scan signal Scan2 at t0≤t＜t0When a low level is input within + T time, the second transistor T2 is in a conducting state, the first transistor T1 is in a diode connection state, and the potential of the first node a gradually rises until the first transistor T1 reaches a saturation critical state. At t ═ t0At the moment of + T, the input is changed from low level to high level, and T is greater than T after the time T0After + T time, the second Scan signal Scan2 is input to high level, where the time T when the second Scan signal is input to low level is less than the timing period; at this time, the second transistor T2 changes from the on state to the off state, and the first transistor T1 is no longer in the diode connection state, so that the potential of the first node a stops rising at a value of:
Figure BDA0002349514260000073
wherein Δ VμIs a mobility-related voltage increment of the first transistor T1 generated to the potential of the gate first node a when the first transistor T1 is in a diode-connected state.
At this time, the absolute value of the gate-source voltage difference of the first transistor T1 is:
Figure BDA0002349514260000081
calculated from formula (5), formula (2), formula (4) and formula (6):
Figure BDA0002349514260000087
when t is0≤t＜t0+ T, the first capacitance C1A second capacitor C2And a first transistor T1 forming a closed loop based onThe circuit loop principle yields:
Figure BDA0002349514260000082
solving the above equation (8) yields:
Figure BDA0002349514260000083
wherein
Figure BDA0002349514260000084
μ、CoxCarrier mobility and gate insulator capacitance of the first transistor T1, respectively, and W and L are a channel width and a length of the first transistor T1, respectively.
When t is equal to t0Then, equation (9) is transformed into:
Figure BDA0002349514260000085
wherein A is a undetermined constant and is solved as follows:
solving equation (4) and equation (10) simultaneously to obtain:
Figure BDA0002349514260000086
substituting equation (11) into equation (10) yields:
Figure BDA0002349514260000091
when t is equal to t0At + T, equation (12) is transformed to:
Figure BDA0002349514260000092
substituting the formula (4) and the formula (13) into the formula (7) to obtain a value of Δ V μ:
Figure BDA0002349514260000093
as can be seen from the formula (14), Δ VμAnd is in a positive correlation with the mobility μ in the k value, i.e., the mobility μ of the first transistor T1. In order to make the first node a in the potential rising state at this stage, the range of the time T for which the second Scan signal Scan2 is input at the low level is 0 < T < 1.5 μ s.
In the S3 stage, the organic light emitting diode OLED does not emit light because the fifth transistor T5 is turned off and no driving current is generated.
D. Lighting phase S4: the first Scan signal Scan1, the third Scan signal Scan3, and the second Scan signal Scan2 are inputted with a high level, the control signal terminal EN is inputted with a low level, the fifth transistor T5 is turned on, and the second transistor T2, the third transistor T3, and the fourth transistor T4 are turned off. The data input signal Vdata may be inputted at high and low levels at the stage S4. The voltage difference between the gate and the source of the first transistor T1 at this time is shown in equation (6).
Since the fifth transistor T5 is turned on, the first transistor T1 operating in the saturation region drives the organic light emitting diode OLED to emit light by the driving current I of the organic light emitting diode OLEDOLEDThe driving current I of the organic light emitting diode OLED is obtained in direct proportion to the square of the difference between the source-gate voltage and the threshold voltage of the driving transistorOLEDAnd the source-gate voltage V of the first transistor T1GSAnd a threshold voltage VTH_1The relationship between them is:
Figure BDA0002349514260000101
substituting equation (6) into equation (15), the current generated by the first transistor T1 to drive the organic light emitting diode OLED is:
Figure BDA0002349514260000102
it can be derived from the formula (16) that the current flowing through the organic light emitting diode OLED is changed into Δ V only with the data input signal Vdata input voltage, the first capacitor C1, the second capacitor C2 in the circuit, and the generated voltage increment Δ VμIn this regard, regardless of the threshold voltage of the first transistor T1 and the first Scan signal Scan1 as a power supply, that is, the pixel driving circuit effectively compensates for the drift of the threshold voltage of the driving transistor and the problem of the circuit voltage drop.
Substituting equation (14) into equation (16) yields the driving current of the organic light emitting diode OLED as:
Figure BDA0002349514260000103
from the equations (16), (17), the drive current and mobility-dependent voltage increment Δ V of the organic light-emitting diode OLED can be derivedμThe k value in the formula is in negative correlation and is in positive correlation with the k value in the original driving current formula, so that the k value in the formula can be effectively offset to a certain extent to the I valueOLEDThereby compensating for the influence of the mobility of the driving transistor on the display effect of the organic light emitting diode OLED.
Fig. 3 is a simulation graph of the voltage at the first node a and the threshold voltage shift of the first transistor T1, showing voltage data measured at different stages of the gate voltage of the first transistor T1, i.e., the voltage at the first node a, and the simulation graph of the voltage at the first node a and the threshold voltage shift. In the zero clearing stage S1, the voltage of the first node A gradually decreases from the voltage value retained in the last period to 0V in the stage time; in the data extraction stage S2, the voltage at the first node A gradually increases until the voltage reaches V at the end of the stageScan1-VTH_T1(ii) a In the data input stage S3, the voltage of the first node a changes due to the change of the data input signal Vdata, and then gradually rises and finally remains stable due to the turn-on and turn-off of the second transistor T2; during the light emitting period S4, the voltage at the first node A causes the first transistor T1 to generate a driving current through the OLEDAnd (4) emitting light. As can be seen from fig. 3, when the threshold voltage of the first transistor T1 is +0.5V or-0.5V, the gate voltage thereof, i.e., the voltage of the first node a, changes from 6.151V to 6.625V or 5.679V, respectively, the change is 0.474V, which is consistent with the theoretical change of 0.5V and only differs by 5.2%, that is, the gate voltage of the first transistor T1 changes with the change of the threshold voltage. The driving current I of the organic light emitting diode OLED is represented by formula (6)OLEDIs not changed by the change of the threshold voltage of the first transistor T1, thereby compensating the influence of the shift of the threshold voltage of the driving transistor on the organic light emitting diode OLED.
FIG. 4 shows the driving current IOLEDA simulation graph of the shift of the threshold voltage of the first transistor shows the driving current I when the threshold voltage of the first transistor T1 changes by 0.5VOLEDThe variation of (2). As can be seen from FIG. 4, when the threshold voltage of the first transistor T1 is +0.5V or-0.5V, the driving current I flowing through the organic light emitting diode OLEDOLEDThe variation is extremely small, and the error rate is only kept below +/-4.2%, so that the influence of the variation of the threshold voltage of the driving transistor on the organic light-emitting diode OLED is effectively compensated by the voltage programming type AMOLED pixel circuit.
FIG. 5 shows the driving current IOLEDThe simulation graph of the mobility variation with the first transistor shows the driving current I flowing through the organic light emitting diode OLED when the mobility of the first transistor T1 varies by ± 30%OLEDThe variation of (2). As can be seen from fig. 5, in the case where the mobility is changed by ± 30%, the current variation is only within 80nA, and the absolute value of the current error rate is also only between 1.2% and 8%. Therefore, the voltage programming type AMOLED pixel circuit well compensates the change of the mobility of the driving transistor and has a good compensation effect.
The power supply voltage drop caused by the parasitic resistance on the power supply line can be simulated by adjusting the magnitude of the power supply signal. FIG. 6 shows the driving current IOLEDThe simulation graph related to the voltage drop variation of the parasitic resistance of the circuit shows that the driving current I of the organic light emitting diode OLED when the power signal, i.e., the first Scan signal Scan1, varies by 0.5VOLEDVariation under different data input signals VdataThe situation is. As can be seen from fig. 6, when the power signal, i.e., the first Scan signal Scan1, drops by 0.5V, the driving current I through the organic light emitting diode OLEDOLEDThe difference between the magnitude of the current and the magnitude of the original current is only within 100nA under different data input signals Vdata, and the maximum error rate of the current is only 8 percent. Therefore, the voltage programming type AMOLED pixel circuit well compensates the influence of the voltage drop of the circuit on the organic light emitting diode OLED.
The voltage programming AMOLED pixel circuit can compensate the influence of threshold voltage change of a driving transistor, the mobility of the driving transistor and circuit voltage drop, and utilizes the first scanning signal Scan1 to replace a traditional power supply signal VDD, so that the number of control lines is reduced, the cost is saved while the brightness of a large-area display panel is uniform, and the control is convenient.

Claims (2)

1. The driving method is applied to a voltage programming type AMOLED pixel driving circuit, and the voltage programming type AMOLED pixel driving circuit comprises a driving module, a zero clearing module, a data input module and a light emitting module;
the driving module comprises a first transistor and a second transistor, wherein the first transistor is controlled by a first scanning signal and used for forming a diode connection state with the second transistor and modulating the voltage of a first node, and the second transistor is controlled by a second scanning signal and used for forming a diode connection state with the first transistor and generating a voltage increment;
the first transistor and the second transistor are both P-type low-temperature polycrystalline silicon thin film transistors, the grid electrode of the first transistor is connected with a first node, the source electrode of the first transistor is connected with a first scanning signal, and the drain electrode of the first transistor is connected with the light emitting module; the grid electrode of the second transistor is connected with the second scanning signal, the source electrode of the second transistor is connected with the first node, and the drain electrode of the second transistor is connected with the drain electrode of the first transistor;
the zero clearing module consists of a third transistor, is respectively connected with the first scanning signal, the grounding terminal and the data input module, and is used for clearing the charges left in the first capacitor and the second capacitor after the previous period is finished under the control of the first scanning signal so as to realize initialization;
the third transistor is a P-type low-temperature polycrystalline silicon thin film transistor, the grid electrode of the third transistor is connected with a first scanning signal, the source electrode of the third transistor is connected with a grounding end, and the drain electrode of the third transistor is connected with a first node;
the data input module comprises a fourth transistor, a first capacitor and a second capacitor, wherein the fourth transistor is controlled by a third scanning signal and is used for inputting the voltage variation of the data input signal to the second node and coupling the voltage variation to the first node through the first capacitor and the second capacitor;
the fourth transistor is a P-type low-temperature polycrystalline silicon thin film transistor, the grid electrode of the fourth transistor is connected with a third scanning signal, the source electrode of the fourth transistor is connected with a data input signal, and the drain electrode of the fourth transistor is connected with a second node; the first capacitor is arranged between the first node and the second node, and the second capacitor is arranged between the first node and the grounding terminal;
the light emitting module comprises a fifth transistor and an organic light emitting diode, wherein the fifth transistor is controlled by the control signal end and is used for controlling the light emitting of the organic light emitting diode;
the fifth transistor is a P-type low-temperature polycrystalline silicon thin film transistor, the grid electrode of the fifth transistor is connected with the control signal end, the source electrode of the fifth transistor is connected with the driving module, the drain electrode of the fifth transistor is connected with the anode of the light-emitting element, and the cathode of the light-emitting element is connected with the negative power supply end;
the method is characterized in that: comprises the steps of (a) preparing a mixture of a plurality of raw materials,
A. initialization stage S1: when the first scanning signal and the third scanning signal are input with low level, and the second scanning signal, the control signal end and the data input signal are input with high level, the third transistor and the fourth transistor are switched on, and the first transistor, the second transistor and the fifth transistor are switched off;
B. data extraction stage S2: the first scanning signal, the control signal end and the data input signal are all input with high level, the third scanning signal and the second scanning signal are input with low level, the fourth transistor and the second transistor are switched on, and the third transistor and the fifth transistor are switched off;
C. data input stage S3: the first scanning signal, the third scanning signal and the control signal end input high level, the data input signal inputs low level, the fourth transistor is turned on, the third transistor and the fifth transistor are turned off, the low level is input in the initial time T of the second scanning signal, the low level is changed into the input high level after the time T, and the time T of the second scanning signal for inputting the low level is less than the time sequence period;
D. lighting phase S4: the first scanning signal, the third scanning signal and the second scanning signal are input with high level, the control signal end is input with low level, the fifth transistor is turned on, and the second transistor, the third transistor and the fourth transistor are turned off.
2. The driving method of the voltage-programmed AMOLED pixel driving circuit as claimed in claim 1, wherein: the range of the time T for inputting the low level of the second scanning signal is 0 < T < 1.5 mus.
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