CN109036288A - Pixel circuit and its control method - Google Patents
Pixel circuit and its control method Download PDFInfo
- Publication number
- CN109036288A CN109036288A CN201811139900.9A CN201811139900A CN109036288A CN 109036288 A CN109036288 A CN 109036288A CN 201811139900 A CN201811139900 A CN 201811139900A CN 109036288 A CN109036288 A CN 109036288A
- Authority
- CN
- China
- Prior art keywords
- transistor
- signal
- pole
- pixel circuit
- light emitting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- 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
- G09G3/3258—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 with pixel circuitry controlling the voltage across the light-emitting element
Abstract
The present invention relates to a kind of pixel circuit and its control methods, including transistor T1, transistor T2, transistor T3, transistor T4, transistor T5, transistor T6, transistor T7, capacitor C1 and light emitting diode D1.Transistor T1 is driving transistor in above-mentioned pixel circuit, pixel circuit carries out voltage compensation by control terminal of the capacitor C1 to transistor T1 using the second reference voltage Vref 2, so that the driving current for flowing through transistor T1 is unrelated with the voltage value of the first power vd D, the driving current for flowing through transistor T1 is the glow current of light emitting diode D1, and then can eliminate influence of the electric current-resistance drop to glow current on the line of the first power vd.The driving current for flowing through transistor T1 is related with the second reference voltage Vref 2, and driving current is not passed through and provides the signal wire of the second reference voltage Vref 2, thus it is wireless on current-resistance pressure drop influence, the luminous homogeneity of screen body can be improved.
Description
Technical field
The present invention relates to display fields, more particularly to pixel circuit and its control method.
Background technique
Organic light emitting display panel has many advantages, such as that the high and low power consumption of contrast, visual angle is wide, reaction speed is fast, is got over because of it
To be applied to display field more.In general, including array arrangement pixel circuit in organic light emitting display panel, pixel circuit is logical
It often include light emitting diode and power supply, the electric current for flowing through light emitting diode is related with supply voltage.And in display panel, each
Distance of the light emitting diode away from power supply is different, therefore pressure drop is also different on the line generated during voltage transmission, thus each hair
The supply voltage that optical diode actually obtains is different, therefore the electric current for flowing through light emitting diode is different, the brightness of light emitting diode
Difference causes the light emission luminance of display panel uneven.
Summary of the invention
Based on this, it is necessary to aiming at the problem that pressure drop on line leads to display panel brightness irregularities, provide a kind of pixel electricity
Road and its control method.
A kind of pixel circuit, which is characterized in that including transistor T1, transistor T2, transistor T3, transistor T4, crystal
Pipe T5, transistor T6, transistor T7, capacitor C1 and light emitting diode D1；
For inputting the first scanning signal, the first pole of the transistor T4 is separately connected the control terminal of the transistor T4
First pole plate of the second pole of the transistor T3, the control terminal of the transistor T1 and the capacitor C1, the transistor T4
The second pole connect the second pole of the transistor T7, for inputting the first reference voltage Vref 1；
For inputting the second scanning signal, the first pole of the transistor T3 is separately connected the control terminal of the transistor T3
First pole of the second pole of the transistor T1 and the transistor T6, the first pole of the transistor T1 is for inputting the first electricity
Source VDD；
For inputting LED control signal, the second pole of the transistor T6 is separately connected the control terminal of the transistor T6
The control terminal of first pole of the anode of the light emitting diode D1 and the transistor T7, the transistor T7 is described for inputting
First scanning signal, the cathode of the light emitting diode D1 is for inputting second source VSS；
For inputting second scanning signal, the first pole of the transistor T2 is used for the control terminal of the transistor T2
Input data signal, the second pole of the transistor T2 be separately connected the capacitor C1 the second pole plate and the transistor T5
Second pole；
For inputting the LED control signal, the first pole of the transistor T5 is used for the control terminal of the transistor T5
Input the second reference voltage Vref 2.
The voltage value of first reference voltage Vref 1 is less than the second source VSS's in one of the embodiments,
Voltage value.
The transistor T1, the transistor T2, the transistor T3, the transistor in one of the embodiments,
T4, the transistor T5, the transistor T6 and the transistor T7 are low-temperature polysilicon film transistor, oxide semiconductor
Any one of thin film transistor (TFT) and amorphous silicon film transistor.
Transistor T1 is driving transistor in above-mentioned pixel circuit, and pixel circuit is passed through using the second reference voltage Vref 2
Capacitor C1 carries out voltage compensation to the control terminal of transistor T1, so as to flow through the driving current and the first power vd D of transistor T1
Voltage value it is unrelated, the driving current for flowing through transistor T1 is the glow current of light emitting diode D1, and then can eliminate
Influence of the electric current-resistance drop to glow current on the line of one power vd.Flow through the driving current and the second reference of transistor T1
Voltage Vref2 is related, and driving current is not passed through and provides the signal wire of the second reference voltage Vref 2, thus it is wireless on electric current-electricity
The influence of damping drop, can be improved the luminous homogeneity of screen body.
A kind of driving method of pixel circuit is based on aforementioned pixel circuit, comprising:
Initial phase, first scanning signal are low level signal, and second scanning signal is high level signal,
So that first reference voltage Vref 1 initializes the pixel circuit；
Data write phase, second scanning signal be low level signal, first scanning signal and it is described shine
Control signal is high level signal, so that the pixel circuit is written in the data-signal；
Light emitting phase, the LED control signal are low level signal, first scanning signal and second scanning
Signal is high level signal, to make current flow through the light emitting diode D1.
In one of the embodiments, in the initial phase, the LED control signal is high level signal.
In one of the embodiments, in the initial phase, the LED control signal is low level signal.
The initial phase includes first stage and second stage in one of the embodiments,；
The first stage, first scanning signal and the LED control signal are low level signal, described to shine
It controls signal and controls the transistor T5 opening, second reference voltage Vref 2 is by the transistor T5 to the capacitor
The second pole plate of C1 is initialized；,
The second stage, first scanning signal are low level signal, and the LED control signal is high level letter
Number.
In one of the embodiments, in the initial phase, first scanning signal controls the transistor T4
It is opened with the transistor T7；
Control terminal and the capacitor of first reference voltage Vref 1 by the transistor T4 to the transistor T1
The first pole plate of C1 is initialized, and the transistor T1 is opened；First reference voltage Vref 1 passes through the transistor T7
The anode of the light emitting diode D1 is initialized, so that the first of the control terminal of the transistor T1 and the capacitor C1
The current potential of pole plate is Vref1.
In one of the embodiments, in the data write phase, second scanning signal controls the transistor
T2 is opened, and the second pole plate of the capacitor C1 is written by the transistor T2 for the data-signal, so that the capacitor C1
The current potential of second pole plate is Vdata；
The transistor T1 is written in supply voltage by the first power vd D, so that the first of the transistor T1 is extremely electric
Position is VDD, and the control terminal potential of the transistor T1 is VDD- | Vth |.
In one of the embodiments, in the light emitting phase, the LED control signal controls the transistor T5 and beats
It opens, second reference voltage Vref 2 is carried out by grid of the transistor T5 and capacitor C1 to the transistor T1
Voltage compensation, so that the electric current for flowing through the transistor T1 is unrelated with the supply voltage that first power supply line provides.
The driving method of above-mentioned pixel circuit compensates for electric current-electricity on the first power supply line by increasing by the second reference voltage
Damping drop, meanwhile, the circuit structure and its control method of the application also compensates for influence of the threshold voltage to glow current, improves
The luminous homogeneity of screen body.
Detailed description of the invention
Fig. 1 is the circuit diagram for the pixel circuit that one embodiment of the application provides；
Fig. 2 is the timing diagram for the pixel circuit drive method that one embodiment of the application provides；
Fig. 3 is the timing diagram for the pixel circuit drive method that the another embodiment of the application provides；
Fig. 4 is the timing diagram for the pixel circuit drive method that the another embodiment of the application provides.
Specific embodiment
In order to make the foregoing objectives, features and advantages of the present invention clearer and more comprehensible, with reference to the accompanying drawing to the present invention
Specific embodiment be described in detail.Many details are explained in the following description in order to fully understand this hair
It is bright.But the invention can be embodied in many other ways as described herein, those skilled in the art can be not
Similar improvement is done in the case where violating intension of the present invention, therefore the present invention is not limited by the specific embodiments disclosed below.
It should be noted that it can directly on the other element when element is referred to as " being set to " another element
Or there may also be elements placed in the middle.When an element is considered as " connection " another element, it, which can be, is directly connected to
To another element or it may be simultaneously present centering elements.Term as used herein " vertical ", " horizontal ", " left side ",
" right side " and similar statement for illustrative purposes only, are not meant to be the only embodiment.
Unless otherwise defined, all technical and scientific terms used herein and belong to technical field of the invention
The normally understood meaning of technical staff is identical.Term as used herein in the specification of the present invention is intended merely to description tool
The purpose of the embodiment of body is not to be to limit the present invention.
Referring to Figure 1, one embodiment of the application provides pixel circuit in one, including transistor T1, transistor T2, crystalline substance
Body pipe T3, transistor T4, transistor T5, transistor T6, transistor T7, capacitor C1 and light emitting diode D1.
Wherein, for the control terminal of transistor T4 for inputting the first scanning signal, the first pole of transistor T4 is separately connected crystalline substance
Second pole of the first pole plate of the second pole of body pipe T3, the control terminal of transistor T1 and capacitor C1, transistor T4 connects transistor
The second pole of T7, for inputting the first reference voltage Vref 1.The control terminal of transistor T3 is brilliant for inputting the second scanning signal
The first pole of body pipe T3 is separately connected the second pole of transistor T1 and the first pole of transistor T6.The first pole of transistor T1 is used for
Input the first power vd D.For inputting LED control signal, the second pole of transistor T6 is separately connected the control terminal of transistor T6
The anode of light emitting diode D1 and the first pole of transistor T7.The control terminal of transistor T7 is for inputting the first scanning signal.Hair
The cathode of optical diode D1 is for inputting second source VSS.The control terminal of transistor T2 is for inputting the second scanning signal, crystal
The first pole of pipe T2 is used for input data signal, and the second pole of transistor T2 is separately connected the second pole plate and transistor of capacitor C1
The second pole of T5.The control terminal of transistor T5 is for inputting LED control signal, and the first pole of transistor T5 is for inputting second
Reference voltage Vref 2.
In the present embodiment, transistor T2, transistor T3, transistor T4, transistor T5, transistor T6, transistor T7 are
Switching transistor, transistor T1 are driving transistor.Capacitor C1 is storage capacitor, and light emitting diode D1 is OLED (Organic
Light-Emitting Diode, Organic Light Emitting Diode).Transistor in the present embodiment is all made of P-type transistor, Ke Yili
Solution, control terminal are the grid of transistor, the source electrode of the first extremely transistor, the drain electrode of the second extremely transistor, to crystal
The control terminal of pipe applies low level so that transistor turns.Certainly, in other embodiments, transistor is also possible to N-type crystal
Pipe, when using N-type transistor as transistor in pixel circuit, control terminal input high level signal to transistor so that
It is connected.
First scanning signal connects the control terminal of transistor T4 and transistor T7, and controllable transistor T4 and transistor T7 is led
It is logical, so that the first reference voltage Vref 1 is initialized by grid of the transistor T4 to transistor T1, and pass through transistor T7
The anode of light emitting diode D1 is initialized.Second scanning signal SCAN2 can control transistor T2 conducting, so that data are believed
Number by transistor T2 be written capacitor C1 the first pole plate.LED control signal can control transistor T5 conducting, so that the second ginseng
Voltage Vref2 is examined to compensate by control terminal of the capacitor C1 to transistor T1 so that flow through the driving current of transistor T1 with
The voltage of first power vd D is unrelated.
In the present embodiment, the first power vd D can be positive voltage, and second source VSS can be negative voltage.Drive transistor
T1 can generate electric current under the action of the first power vd D, which flows through light emitting diode D1 so that light emitting diode D1 is sent out
Light, when light emitting diode D1 shines, electric current flows to second source VSS from light emitting diode D1.
Transistor T1 is driving transistor in pixel circuit provided by the above embodiment, and pixel circuit is using second with reference to electricity
Press Vref2 to carry out voltage compensation to the control terminal of transistor T1 by capacitor C1 so that flow through the driving current of transistor T1 with
The voltage value of first power vd D is unrelated, and the driving current for flowing through transistor T1 is the glow current of light emitting diode D1, in turn
Influence of the electric current-resistance drop to glow current on the line of the first power vd can be eliminated.Flow through the driving current of transistor T1
It is related with the second reference voltage Vref 2, and driving current is not passed through and provides the signal wire of the second reference voltage Vref 2, thus it is wireless
On current-resistance pressure drop influence, can be improved screen body luminous homogeneity.
In one embodiment, transistor T2, transistor T3, transistor T4, transistor T5, transistor T6, transistor T7
It can be any in low-temperature polysilicon film transistor, oxide semiconductor thin-film transistor and amorphous silicon film transistor
Kind.
One embodiment of the application provides a kind of display panel, the aforementioned pixel circuit including array arrangement.Display surface
Plate further includes data driver, scanner driver and light emission controller.A plurality of first scan signal line and the second scan signal line
One end be separately connected every row pixel circuit, the other end connects scanner driver, and scanner driver provides scanning signal, and passes through
Scan signal line is transmitted in pixel circuit.A plurality of data signal line one end connects each column pixel circuit, and the other end connects data
Driver, data driver provides data-signal, and is transmitted to pixel circuit by data signal line.A plurality of LED control signal
Line one end connects every row pixel circuit, and the other end connects light emission controller, and light emission controller provides LED control signal, and passes through
LED control signal line is transmitted to pixel circuit.
One embodiment of the application provides a kind of display device, including above-mentioned display panel.
Referring to Figure 1 with Fig. 2, one embodiment of the application provides a kind of driving method of pixel circuit, the driving
Method is based on pixel circuit shown in FIG. 1.The driving method includes following three phases:
Initial phase t1, the first scanning signal are low level signal, and the second scanning signal is high level signal, so that the
One reference voltage Vref 1 initializes the pixel circuit.
Data write phase t2, the second scanning signal are low level signal, and the first scanning signal and LED control signal are
High level signal, so that the pixel circuit is written in data-signal.
Light emitting phase t3, LED control signal are low level signal, and the first scanning signal and the second scanning signal are high electricity
Ordinary mail number, to make current flow through light emitting diode D1.
Specifically, referring to Fig. 2, in one embodiment, in initial phase t1, the first scanning signal is low level letter
Number, the first scanning signal controls transistor T4 and opens, so that the first reference voltage Vref 1 is by transistor T4 to transistor T1's
The first pole plate of control terminal and capacitor C1 are initialized, so that transistor T1 is connected.Meanwhile first reference voltage Vref 1 it is logical
Transistor T7 is crossed to initialize the anode of light emitting diode D1.Second scanning signal be high level signal, transistor T2 and
Transistor T3 cut-off.LED control signal is also high level signal, transistor T5 and transistor T6 cut-off.It is understood that
The voltage value of first reference voltage Vref 1 is less than the voltage value of second source VSS, to guarantee the light emitting diode D1 in initialization
It does not shine.Initialization can eliminate influence of the residual current to this light emitting phase of a light emitting phase, guarantee all pixels circuit
It is in same original state, the luminous homogeneity of screen body can be improved.
In data write phase t2, the second scanning signal is low level signal, transistor T2 conducting.Data-signal passes through crystalline substance
The second pole plate of capacitor C1 is written in body pipe T2, so that the second plate potential of capacitor C1 is Vdata.Due in initial phase
T1, transistor T1 have been connected, and in data write phase t2, after circuit state is stablized, the first electrode potential of transistor T1 is VDD,
The control terminal potential of transistor T1 is VDD- | Vth |, the compensation to threshold voltage may be implemented.
In light emitting phase t3, LED control signal is low level, transistor T5 and transistor T6 conducting.Second reference voltage
The second pole plate of capacitor C1 is written by transistor T5 by Vref2.The current potential of the second pole plate of capacitor C1 becomes Vref2 from Vdata.
Since transistor T3 and transistor T4 end, and the capacity of capacitor C1 is much larger than the parasitic capacitance of other transistors, therefore capacitor C1
Voltage difference it is constant, the current potential of the first pole plate of capacitor C1 can also change with the second pole plate, and variable quantity be Vref2-Vdata.
Due to the first pole plate of the control terminal connection capacitor C1 of transistor T1, therefore the potential change amount of the control terminal of transistor T1 is
Vref2-Vdata, then the current potential of the control terminal of transistor T1 is VDD- | Vth |+Vref2-Vdata, further, transistor T1
Vgs=Vref2-Vdata- | Vth |.According to the leakage current formula I=K* of transistor T1 (Vgs+ | Vth |)2It is found that the second ginseng
It examines voltage Vref2 to compensate the control terminal of transistor T1, so that flowing through the leakage current and the first power vd D of transistor T1
It is unrelated.The leakage current for flowing through transistor T1 is the glow current for flowing through light emitting diode D1, therefore glow current and the first power supply
VDD is unrelated, and then can eliminate influence of the current-resistance pressure drop to electric current on the first power supply line, improves the luminous equal of screen body
One property.
In one embodiment, pixel circuit shown in Fig. 1 can also be driven with other methods, and timing control figure is as shown in Figure 3.
In the present embodiment, in initial phase t1, the first scanning signal and LED control signal are low level signal.First scanning letter
Number control transistor T4 and transistor T7 conducting so that the first reference voltage Vref 1 by transistor T4 to the first of capacitor C1
The control terminal of pole plate and transistor T1 are initialized, and are carried out initially by anode of the transistor T7 to light emitting diode D1
Change.LED control signal controls transistor T5 and transistor T6 conducting, and the second reference voltage Vref 2 is by transistor T5 to capacitor
The first pole plate of C1 is initialized, so that the first pole plate and the second pole plate of capacitor C1 is initialised in initial phase,
The init state of each pixel circuit is identical, can better ensure that the luminous homogeneity of screen body.
The clock signal control method of data write phase t2 and light emitting phase t3 is identical as control method shown in Fig. 2,
This is repeated no more.
In one embodiment, pixel circuit shown in Fig. 1 also can be used other methods to drive, and timing control figure is as shown in Figure 4.
In the present embodiment, initial phase includes first stage t1 and second stage t2.T1 in the first stage, the first scanning signal and hair
Optical control signal is low level.First scanning signal controls transistor T4 and transistor T7 conducting, so that the first reference voltage
Vref1 initializes the first pole plate of capacitor C1 and the control terminal of transistor T1 by transistor T4, and passes through transistor
T7 initializes the anode of light emitting diode D1.LED control signal controls transistor T5 and transistor T6 and is connected, and second
Reference voltage Vref 2 is initialized by the first pole plate of the transistor T5 to capacitor C1, and then makes the first pole plate of capacitor C1
It is initialised with the second pole plate.In second stage t2, the first scanning signal still keeps low level, the first reference voltage Vref 1
Persistently the first pole plate to the control terminal of transistor T1, capacitor C1 and the anode of light emitting diode D1 initialize.Shine control
Signal processed jumps to high level, transistor T5 and transistor T6 cut-off by low level.Due in t1 stage, transistor T1, crystal
Pipe T6 and transistor T7 are both turned on, and under the action of the first power vd D, can generate loop current, by the first power vd D through crystal
Pipe T1, transistor T6 and transistor T7 flow to the first reference voltage Vref 1, then power consumption can be generated in circuit.And in second stage
T2, LED control signal become high level, transistor T6 cut-off, and circuit disconnects, and will not continue to generate electric current, can reduce pixel electricity
The power consumption on road.
The clock signal control method of data write phase t2 and light emitting phase t3 is identical as control method shown in Fig. 2,
This is repeated no more.
Fig. 2, Fig. 3 are similar with the working principle of the control method of pixel circuit shown in Fig. 4, mainly introduce be based on Fig. 1 below
With the working principle of pixel circuit shown in Fig. 2:
In initial phase t1, the first scanning signal is low level signal, and the second scanning signal and LED control signal are
High level signal.Transistor T4 and transistor T7 conducting, transistor T2, transistor T3, transistor T5, transistor T6 cut-off.
Since transistor T4 is connected, the first reference voltage Vref 1 is by transistor T4 to the control terminal and electricity of transistor T1
The first pole plate for holding C1 is initialized.Wherein, the first reference voltage Vref 1 can be negative voltage, the first reference voltage Vref 1
The control terminal for acting on transistor T1 can be such that transistor T1 is connected.Since transistor T7 is connected, the first reference voltage Vref 1 is right
The anode of light emitting diode D1 is initialized.
It is understood that the voltage value of the first reference voltage Vref 1 is less than the voltage value of second source VSS, to guarantee
In initialization, light emitting diode D1 does not shine.Initialization can eliminate the residual current of a light emitting phase to this light emitting phase
It influences, guarantees that all pixels circuit is in same original state, the luminous homogeneity of screen body can be improved.
In data write phase t2, the second scanning signal is low level signal, the first scanning signal and LED control signal
For high level signal.Transistor T2 and transistor T3 conducting, in initial phase, transistor T1 has been connected.Transistor T4, crystal
Pipe T7, transistor T5 cut-off.
Since transistor T2 is connected, the second pole plate of capacitor C1 is written by transistor T2 by data-signal for data voltage,
So that the current potential of the second pole plate of capacitor C1 is Vdata.Since transistor T1 is connected, the first power vd D to transistor T1 the
The charging of one pole, after circuit state is stablized, the first electrode potential of transistor T1 is VDD, and the control terminal potential of transistor T1 is
VDD- | Vth |, it is achieved that the compensation of the threshold voltage to transistor T1.
In light emitting phase t3, LED control signal is low level signal, and the first scanning signal and the second scanning signal are
High level signal.Transistor T5 and transistor T6 conducting, transistor T1 are tended to remain on.Transistor T2, transistor T3, crystal
Pipe T4, transistor T7 cut-off.
Since transistor T5 is connected, the second pole plate of capacitor C1 is written by transistor T5 for the second reference voltage Vref 2, therefore
The current potential of the second pole plate of capacitor C1 becomes Vref2 from Vdata.Since transistor T3 and transistor T4 ends, and capacitor C1
Capacity is much larger than the capacity of the parasitic capacitance of other transistors, therefore the voltage difference of capacitor C1 is constant, according to capacitive coupling principle,
In the case that the voltage difference of capacitor C1 remains unchanged, the current potential of the first pole plate of capacitor C1 can also become with the variation of the second pole plate
Change.And the second plate potential of capacitor C1 is become the Vref2 of light emitting phase t3 from the Vdata of data write phase t2, variable quantity
For Vref2-Vdata, therefore the variable quantity of the current potential of the first pole plate of capacitor C1 is identical as the potential change amount of the second pole plate, i.e. crystal
The potential change amount of pipe T1 control terminal and the potential change amount of the second pole plate are identical, then in data write phase t2, transistor T1
Control terminal potential be VDD- | Vth |+Vref2-Vdata.Therefore, the Vgs=VDD- of transistor T1 | Vth |+Vref2-
Vdata-VDD=Vref2-Vdata- | Vth |.Flow through the driving current of transistor T1 are as follows:
I=K* (Vgs-Vth)2=K* (Vref2-Vdata- | Vth |+| Vth |)2=K* (Vref2-Vdata)2
Wherein, K=1/2* μ * Cox*W/L.μ is the electron mobility of transistor T1, and Cox is transistor T1 unit area
Gate oxide capacitance, W are the channel widths of transistor T1, and L is the channel length of transistor T1.Flow through the driving electricity of transistor T1
Stream is the glow current for flowing through light emitting diode D1.The luminous electricity of light emitting diode D1 is flowed through it can be seen from above-mentioned formula
Stream is unrelated with the voltage of the first power vd D, also unrelated with the threshold voltage of transistor, meanwhile, glow current is not passed through the second ginseng
Examine pressure-wire.Therefore the circuit structure and its driving method that embodiments herein provides are by increasing the compensation of the second reference voltage
Current-resistance pressure drop on first power supply line, meanwhile, the circuit structure and its control method of the application also compensates for threshold value electricity
The influence to glow current is pressed, the luminous homogeneity of screen body is improved.
Each technical characteristic of embodiment described above can be combined arbitrarily, for simplicity of description, not to above-mentioned reality
It applies all possible combination of each technical characteristic in example to be all described, as long as however, the combination of these technical characteristics is not deposited
In contradiction, all should be considered as described in this specification.
The embodiments described above only express several embodiments of the present invention, and the description thereof is more specific and detailed, but simultaneously
It cannot therefore be construed as limiting the scope of the patent.It should be pointed out that coming for those of ordinary skill in the art
It says, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to protection of the invention
Range.Therefore, the scope of protection of the patent of the invention shall be subject to the appended claims.
Claims (10)
1. a kind of pixel circuit, which is characterized in that including transistor T1, transistor T2, transistor T3, transistor T4, transistor
T5, transistor T6, transistor T7, capacitor C1 and light emitting diode D1；
The control terminal of the transistor T4 is separately connected described for inputting the first scanning signal, the first pole of the transistor T4
First pole plate of the second pole of transistor T3, the control terminal of the transistor T1 and the capacitor C1, the of the transistor T4
Two poles connect the second pole of the transistor T7, for inputting the first reference voltage Vref 1；
The control terminal of the transistor T3 is separately connected described for inputting the second scanning signal, the first pole of the transistor T3
First pole of the second pole of transistor T1 and the transistor T6, the first pole of the transistor T1 is for inputting the first power supply
VDD；
The control terminal of the transistor T6 is separately connected described for inputting LED control signal, the second pole of the transistor T6
First pole of the anode of light emitting diode D1 and the transistor T7, the control terminal of the transistor T7 is for inputting described first
Scanning signal, the cathode of the light emitting diode D1 is for inputting second source VSS；
The control terminal of the transistor T2 is for inputting second scanning signal, and the first pole of the transistor T2 is for inputting
Data-signal, the second pole of the transistor T2 be separately connected the capacitor C1 the second pole plate and the transistor T5 second
Pole；
The control terminal of the transistor T5 is for inputting the LED control signal, and the first pole of the transistor T5 is for inputting
Second reference voltage Vref 2.
2. pixel circuit according to claim 1, which is characterized in that the voltage value of first reference voltage Vref 1 is small
In the voltage value of the second source VSS.
3. pixel circuit according to claim 1, which is characterized in that the transistor T1, the transistor T2, the crystalline substance
Body pipe T3, the transistor T4, the transistor T5, the transistor T6 and the transistor T7 are that low-temperature polysilicon film is brilliant
Any one of body pipe, oxide semiconductor thin-film transistor and amorphous silicon film transistor.
4. a kind of driving method of pixel circuit, is based on pixel circuit of any of claims 1-3, feature exists
In, comprising:
Initial phase, first scanning signal are low level signal, and second scanning signal is high level signal, so that
First reference voltage Vref 1 initializes the pixel circuit；
Data write phase, second scanning signal are low level signal, first scanning signal and the light emitting control
Signal is high level signal, so that the pixel circuit is written in the data-signal；
Light emitting phase, the LED control signal are low level signal, first scanning signal and second scanning signal
For high level signal, to make current flow through the light emitting diode D1.
5. the driving method of pixel circuit according to claim 4, which is characterized in that described in the initial phase
LED control signal is high level signal.
6. the driving method of pixel circuit according to claim 4, which is characterized in that described in the initial phase
LED control signal is low level signal.
7. the driving method of pixel circuit according to claim 6, which is characterized in that the initial phase includes first
Stage and second stage；
The first stage, first scanning signal and the LED control signal are low level signal, the light emitting control
Signal controls the transistor T5 and opens, and second reference voltage Vref 2 is by the transistor T5 to the capacitor C1's
Second pole plate is initialized；,
The second stage, first scanning signal are low level signal, and the LED control signal is high level signal.
8. the driving method of the pixel circuit according to any one of claim 5-7, which is characterized in that in the initialization
Stage, first scanning signal control the transistor T4 and transistor T7 and open；
First reference voltage Vref 1 is by the transistor T4 to the control terminal of the transistor T1 and the capacitor C1
First pole plate is initialized, and the transistor T1 is opened；First reference voltage Vref 1 is by the transistor T7 to institute
The anode for stating light emitting diode D1 is initialized, so that the first pole plate of the control terminal of the transistor T1 and the capacitor C1
Current potential be Vref1.
9. the driving method of pixel circuit according to claim 8, which is characterized in that in the data write phase, institute
It states the second scanning signal and controls the transistor T2 opening, the capacitor C1 is written by the transistor T2 in the data-signal
The second pole plate so that the current potential of the second pole plate of the capacitor C1 be Vdata；
The transistor T1 is written in supply voltage by the first power vd D, so that the first electrode potential of the transistor T1 is
The control terminal potential of VDD, the transistor T1 are VDD- | Vth |.
10. the driving method of pixel circuit according to claim 9, which is characterized in that in the light emitting phase, the hair
Optical control signal controls the transistor T5 and opens, and second reference voltage Vref 2 passes through the transistor T5 and the electricity
Hold C1 and voltage compensation is carried out to the grid of the transistor T1, so as to flow through the electric current and first power supply of the transistor T1
The supply voltage that line provides is unrelated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811139900.9A CN109036288B (en) | 2018-09-28 | 2018-09-28 | Pixel circuit and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811139900.9A CN109036288B (en) | 2018-09-28 | 2018-09-28 | Pixel circuit and control method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109036288A true CN109036288A (en) | 2018-12-18 |
| CN109036288B CN109036288B (en) | 2020-09-22 |
Family
ID=64615319
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811139900.9A Active CN109036288B (en) | 2018-09-28 | 2018-09-28 | Pixel circuit and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109036288B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111179835A (en) * | 2020-02-18 | 2020-05-19 | 京东方科技集团股份有限公司 | Pixel circuit, pixel driving method and display device |
| WO2020177563A1 (en) * | 2019-03-01 | 2020-09-10 | 京东方科技集团股份有限公司 | Pixel circuit, display substrate and display apparatus |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110134100A1 (en) * | 2009-12-08 | 2011-06-09 | Bo-Yong Chung | Pixel circuit and organic electro-luminescent display apparatus |
| CN103971640A (en) * | 2014-05-07 | 2014-08-06 | 京东方科技集团股份有限公司 | Pixel driving circuit, driving method of pixel driving circuit and display device |
| CN104282263A (en) * | 2014-09-25 | 2015-01-14 | 京东方科技集团股份有限公司 | Pixel circuit, drive method thereof, display panel and display device |
| CN104485067A (en) * | 2014-12-08 | 2015-04-01 | 上海大学 | OLED (Organic Light-Emitting Diode) pixel driving circuit |
| US20160307508A1 (en) * | 2014-06-04 | 2016-10-20 | Shanghai Tianma AM-OLED Co., Ltd. | Pixel compensating circuit and method of organic light emitting display |
| EP3159878A1 (en) * | 2014-06-18 | 2017-04-26 | BOE Technology Group Co., Ltd. | Pixel circuit and display device |
| CN106875894A (en) * | 2017-03-13 | 2017-06-20 | 京东方科技集团股份有限公司 | A kind of image element circuit and its driving method, display device |
-
2018
- 2018-09-28 CN CN201811139900.9A patent/CN109036288B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110134100A1 (en) * | 2009-12-08 | 2011-06-09 | Bo-Yong Chung | Pixel circuit and organic electro-luminescent display apparatus |
| CN103971640A (en) * | 2014-05-07 | 2014-08-06 | 京东方科技集团股份有限公司 | Pixel driving circuit, driving method of pixel driving circuit and display device |
| US20160307508A1 (en) * | 2014-06-04 | 2016-10-20 | Shanghai Tianma AM-OLED Co., Ltd. | Pixel compensating circuit and method of organic light emitting display |
| EP3159878A1 (en) * | 2014-06-18 | 2017-04-26 | BOE Technology Group Co., Ltd. | Pixel circuit and display device |
| CN104282263A (en) * | 2014-09-25 | 2015-01-14 | 京东方科技集团股份有限公司 | Pixel circuit, drive method thereof, display panel and display device |
| CN104485067A (en) * | 2014-12-08 | 2015-04-01 | 上海大学 | OLED (Organic Light-Emitting Diode) pixel driving circuit |
| CN106875894A (en) * | 2017-03-13 | 2017-06-20 | 京东方科技集团股份有限公司 | A kind of image element circuit and its driving method, display device |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020177563A1 (en) * | 2019-03-01 | 2020-09-10 | 京东方科技集团股份有限公司 | Pixel circuit, display substrate and display apparatus |
| US11335269B2 (en) | 2019-03-01 | 2022-05-17 | Boe Technology Group Co., Ltd. | Pixel circuit, display substrate and display apparatus |
| US11837169B2 (en) | 2019-03-01 | 2023-12-05 | Boe Technology Group Co., Ltd. | Pixel circuit, display substrate and display apparatus |
| CN111179835A (en) * | 2020-02-18 | 2020-05-19 | 京东方科技集团股份有限公司 | Pixel circuit, pixel driving method and display device |
| CN111179835B (en) * | 2020-02-18 | 2021-05-25 | 京东方科技集团股份有限公司 | Pixel circuit, pixel driving method and display device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109036288B (en) | 2020-09-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106652911B (en) | OLED pixel driving circuit and OLED display | |
| CN106504707B (en) | OLED pixel mixed compensation circuit and mixed compensation method | |
| CN107316614B (en) | AMOLED pixel-driving circuit | |
| CN109147676A (en) | Pixel circuit and its control method, display panel, display device | |
| CN106097964B (en) | Pixel circuit, display panel, display equipment and driving method | |
| CN105741781B (en) | AMOLED pixel-driving circuits and image element driving method | |
| CN109243369A (en) | Display panel, the driving method of pixel circuit and display device | |
| CN104658482B (en) | AMOLED pixel-driving circuits and image element driving method | |
| CN109215582A (en) | Display panel, the driving method of pixel circuit and display device | |
| CN103971640B (en) | A kind of pixel-driving circuit and driving method thereof and display device | |
| CN110223636A (en) | Pixel-driving circuit and its driving method, display device | |
| CN104157238B (en) | Image element circuit, the driving method of image element circuit and display device | |
| CN105427805B (en) | Pixel-driving circuit, method, display panel and display device | |
| CN105931599B (en) | Pixel-driving circuit and its driving method, display panel, display device | |
| CN103198793B (en) | Pixel circuit, drive method and display device thereof | |
| CN110264946A (en) | A kind of pixel circuit and display device | |
| CN108538241A (en) | Pixel circuit and its driving method, display device | |
| CN109166528A (en) | Pixel circuit and its driving method | |
| CN108335671B (en) | AMOLED pixel-driving circuit and driving method | |
| CN106504700A (en) | AMOLED pixel-driving circuits and driving method | |
| CN106504701B (en) | AMOLED pixel-driving circuit and image element driving method | |
| CN105489165B (en) | Pixel compensation circuit, method, scan drive circuit and flat display apparatus | |
| CN104575394A (en) | AMOLED (active matrix organic light emitting display) pixel driving circuit and pixel driving method | |
| CN109148548A (en) | Array substrate and display panel | |
| CN106067291A (en) | A kind of pixel-driving circuit and driving method, display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |