CN107301844A - OLED pixel drive circuit - Google Patents

OLED pixel drive circuit Download PDF

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Publication number
CN107301844A
CN107301844A CN201710589084.0A CN201710589084A CN107301844A CN 107301844 A CN107301844 A CN 107301844A CN 201710589084 A CN201710589084 A CN 201710589084A CN 107301844 A CN107301844 A CN 107301844A
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CN
China
Prior art keywords
scanning signal
film transistor
tft
node
thin film
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CN201710589084.0A
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Chinese (zh)
Inventor
陈小龙
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深圳市华星光电半导体显示技术有限公司
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Priority to CN201710589084.0A priority Critical patent/CN107301844A/en
Publication of CN107301844A publication Critical patent/CN107301844A/en

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    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control 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
    • G09G3/22Control 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
    • G09G3/30Control 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
    • G09G3/32Control 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]
    • G09G3/3208Control 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]
    • G09G3/3266Details of drivers for scan electrodes
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control 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
    • G09G3/22Control 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
    • G09G3/30Control 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
    • G09G3/32Control 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]
    • G09G3/3208Control 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]
    • G09G3/3275Details of drivers for data electrodes
    • G09G3/3291Details of drivers for data electrodes in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/02Improving the quality of display appearance
    • G09G2320/0233Improving the luminance or brightness uniformity across the screen

Abstract

The present invention relates to a kind of OLED pixel drive circuit.The OLED pixel drive circuit includes:First film transistor (T1), second thin film transistor (TFT) (T2), 3rd thin film transistor (TFT) (T3), 4th thin film transistor (TFT) (T4), 5th thin film transistor (TFT) (T5), 6th thin film transistor (TFT) (T6), Organic Light Emitting Diode (OLED), and electric capacity (C1);Include three phases during the OLED pixel drive circuit works:Control the 4th thin film transistor (TFT) (T4) to open in the first stage, initialize the current potential (Vg) of the first node (g) to fixed potential;The current potential (Vg) of the first node (g) is lifted in second stage, until the threshold voltage of current potential (Vg)=data voltage (the Vdata)-first film transistor (T1) of the first node (g);In the phase III, the Organic Light Emitting Diode (OLED) starts luminescence display.The OLED pixel drive circuit of the present invention uses less TFT quantity (6), eliminates influences of the threshold voltage vt h of driving TFT in OLED drive to light emitting diode, improves Display panel uniformity.

Description

OLED pixel drive circuit

Technical field

The present invention relates to display technology field, more particularly to a kind of OLED pixel drive circuit.

Background technology

Organic Light Emitting Diode (Organic Light Emitting Diode, OLED) display device have self-luminous, Driving voltage is low, luminous efficiency is high, the response time is short, definition and contrast is high, nearly 180 ° of visual angles, temperature in use scope are wide, Many advantages, such as Flexible Displays are with large area total colouring can be achieved, it is that the display for most having development potentiality is filled to be known as by industry Put.

As shown in Figure 1a, its 2T1C (2transistor 1capacitance, the electric capacity of 2 transistor 1) for being existing OLED Pixel-driving circuit schematic diagram, including first film transistor T1, the second thin film transistor (TFT) T2, electric capacity Cst and organic light emission two Pole pipe OLED;First film transistor T1 grid is electrically connected with the second thin film transistor (TFT) T2 source electrode, and source electrode access power supply is just Voltage OVDD, drain electrode is electrically connected with organic light emitting diode D1 anode;Second thin film transistor (TFT) T2 grid access grid drives Dynamic signal Gate, drain incoming data signal Data, and source electrode is electrically connected with first film transistor T1 grid;Electric capacity Cst's One end is electrically connected with first film transistor T1 grid, and the other end is electrically connected at first film transistor T1 source electrode;Have Machine light emitting diode OLED anode is electrically connected with first film transistor T1 drain electrode, negative electrode access power supply negative voltage OVSS.

According to transistor I-V equations:

Ids,sat=k (VGS-Vth,T2)2=k (VG-VS-Vth,T2)2 (1)

Wherein K is the intrinsic conduction factor, Ids,satSize with driving TFT (Driving TFT) (T2) threshold voltage Vth is relevant.

The reasons such as the unstability due to panel processing procedure so that the driving TFT of each sub-pixel (Sub-pixel) in panel The threshold voltage vt h of (Driving TFT) has difference.Therefore, though data voltage (Vdata) it is equal be applied to each pixel Driving TFT, the inconsistent situation of electric current for flowing into Organic Light Emitting Diode (OLED) also occurs, causes image quality Homogeneity be difficult to.

In addition, with the passage of driving TFT driving times, TFT material agings, variation can be caused, cause the threshold for driving TFT The problems such as threshold voltage Vth can drift about.And the degree of aging of TFT materials is different in plate, cause the threshold value of each driving TFT in panel Voltage Vth drift values are different, will also result in the non-uniform phenomenon of Display panel, and with the passage of driving time, TFT materials Aging become more serious.Even if driving voltage is identical, the glow current for flowing through Organic Light Emitting Diode is also likely to difference, makes Into brightness irregularities.In addition the aging of luminescent crystal tube device, can rise the cut-in voltage of lighting transistor, flow into organic hair The electric current of optical diode is gradually reduced, and causes the problems such as panel luminance reduction, luminous efficiency decline.

I in existing OLED 2T1C drive circuits as shown in Figure 1ads,satSize with driving TFT threshold voltage vt h Relevant, this drive circuit can cause the non-uniform phenomenon of Display panel.

Fig. 1 b are existing OLED 8T1C pixel compensation drive circuit schematic diagrams, including 8 electric capacity of TFT, T1~T8,1 C, and OLED;Fig. 1 c are the drive signal timing diagram of circuit shown in Fig. 1 b.Although above-mentioned 8T1C internal compensations framework can disappear Except driving TFT Vth, but 8T1C used framework TFT quantity is more, the aperture opening ratio of panel can be caused to decline, display brightness Reduction, and more TFT is the problems such as also can produce other parasitic capacitances;On the other hand, this internal after frame structure needs two additionally Power supply (Vref, Vini).

Fig. 1 d are existing OLED 7T1C pixel compensation drive circuit schematic diagrams, including 7 electric capacity of TFT, T1~T7,1 Cst, and OLED;Fig. 1 e are the drive signal timing diagram of circuit shown in Fig. 1 d.Although above-mentioned 7T1C internal compensations framework can be with Driving TFT Vth is eliminated, but 7T1C used framework TFT quantity is more, and the aperture opening ratio of panel can be caused to decline, and shows bright Degree reduction, and more TFT is the problems such as also can produce other parasitic capacitances.

The content of the invention

Therefore, it is an object of the invention to provide the OLED pixel drive circuit of 6T1C a kind of, OLED drive is eliminated Influences of the middle driving TFT threshold voltage vt h to light emitting diode.

To achieve the above object, the invention provides a kind of OLED pixel drive circuit, including:

First film transistor, its grid connection first node, source electrode and drain electrode connect Section Point and Section three respectively Point;

Second thin film transistor (TFT), its grid connects the first scanning signal, source electrode and drain electrode connection first node and the respectively Three nodes;

3rd thin film transistor (TFT), its grid connects the first scanning signal, and source electrode and drain electrode connect Section Point sum respectively According to voltage;

4th thin film transistor (TFT), its grid connects the second scanning signal, and source electrode and drain electrode connect first node and ground respectively;

5th thin film transistor (TFT), its grid connect the 3rd scanning signal, source electrode and drain electrode respectively connection power supply positive voltage and Section Point;

6th thin film transistor (TFT), its grid connects the 3rd scanning signal, and source electrode and drain electrode connect the 3rd node and had respectively The anode of machine light emitting diode;

The negative electrode connection power supply negative voltage of Organic Light Emitting Diode;

Electric capacity, its one end connection first node, other end connection power supply positive voltage;

The sequential of first scanning signal, the second scanning signal and the 3rd scanning signal is configured to drive the OLED pixel Include three phases when circuit works:

Control the 4th thin film transistor (TFT) to open in the first stage, initialize the current potential of the first node to fixed potential;

Lift the current potential of the first node in second stage, until the first node current potential=data voltage-this first The threshold voltage of thin film transistor (TFT);

In the phase III, the Organic Light Emitting Diode starts luminescence display.

Wherein, in the first stage, first scanning signal is high potential, and the second scanning signal is low potential, the 3rd scanning Signal is high potential, and the fixed potential is ground.

Wherein, in second stage, first scanning signal is low potential, and the second scanning signal is high potential, the 3rd scanning Signal is high potential.

Wherein, in the phase III, first scanning signal is high potential, and the second scanning signal is high potential, the 3rd scanning Signal is low potential.

Present invention also offers a kind of OLED pixel drive circuit, including:

First film transistor, its grid connection first node, source electrode and drain electrode connect Section Point and Section three respectively Point;

Second thin film transistor (TFT), its grid connects the first scanning signal, source electrode and drain electrode connection first node and the respectively Three nodes;

3rd thin film transistor (TFT), its grid connects the second scanning signal, and source electrode and drain electrode connect Section Point sum respectively According to voltage;

4th thin film transistor (TFT), its grid connects the first scanning signal, and source electrode and drain electrode are connected to machine light-emitting diodes The anode and ground of pipe;

5th thin film transistor (TFT), its grid connect the 3rd scanning signal, source electrode and drain electrode respectively connection power supply positive voltage and Section Point;

6th thin film transistor (TFT), its grid connects the 4th scanning signal, and source electrode and drain electrode connect the 3rd node and had respectively The anode of machine light emitting diode;

The negative electrode connection power supply negative voltage of Organic Light Emitting Diode;

Electric capacity, its one end connection first node, other end connection power supply positive voltage;

First scanning signal, the second scanning signal, the sequential of the 3rd scanning signal and the 4th scanning signal are configured to make Include three phases during the OLED pixel drive circuit works:

Control the 4th thin film transistor (TFT) to open in the first stage, initialize the current potential of the first node to fixed potential;

The current potential of the first node (g) is lifted in second stage, until current potential=data voltage of the first node-should The threshold voltage of first film transistor;

In the phase III, the Organic Light Emitting Diode starts luminescence display.

Wherein, in the first stage, first scanning signal is low potential, and the second scanning signal is high potential, the 3rd scanning Signal is high potential, and the 4th scanning signal is low potential, and the fixed potential is ground.

Wherein, in second stage, first scanning signal is low potential, and the second scanning signal is low potential, the 3rd scanning Signal is high potential, and the 4th scanning signal is high potential.

Wherein, in the phase III, first scanning signal is high potential, and the second scanning signal is high potential, the 3rd scanning Signal is low potential, and the 4th scanning signal is low potential.

Present invention also offers a kind of OLED pixel drive circuit, including:

First film transistor, its grid connection first node, source electrode and drain electrode connect Section Point and Section three respectively Point;

Second thin film transistor (TFT), its grid connects the first scanning signal, source electrode and drain electrode connection first node and the respectively Three nodes;

3rd thin film transistor (TFT), its grid connects the second scanning signal, and source electrode and drain electrode connect Section Point sum respectively According to voltage;

4th thin film transistor (TFT), its grid connects the 3rd scanning signal, source electrode and drain electrode connection first node and the respectively Two nodes;

5th thin film transistor (TFT), its grid connect the 4th scanning signal, source electrode and drain electrode respectively connection power supply positive voltage and Section Point;

6th thin film transistor (TFT), its grid connects the 4th scanning signal, and source electrode and drain electrode connect the 3rd node and had respectively The anode of machine light emitting diode;

The negative electrode connection power supply negative voltage of Organic Light Emitting Diode;

Electric capacity, its one end connection first node, other end connection power supply positive voltage;

First scanning signal, the second scanning signal, the sequential of the 3rd scanning signal and the 4th scanning signal are configured to make Include three phases during the OLED pixel drive circuit works:

Control the 4th thin film transistor (TFT) to open in the first stage, initialize the current potential of the first node to fixed potential;

Lift the current potential of the first node in second stage, until the first node current potential=data voltage-this first The threshold voltage of thin film transistor (TFT);

In the phase III, the Organic Light Emitting Diode starts luminescence display.

Wherein, in the first stage, first scanning signal is high potential, and the second scanning signal is low potential, the 3rd scanning Signal is low potential, and the 4th scanning signal is high potential;The data voltage is fixed value, and the fixed potential is the fixed value.

Wherein, in second stage, first scanning signal is low potential, and the second scanning signal is low potential, the 3rd scanning Signal is high potential, and the 4th scanning signal is high potential

Wherein, in the phase III, first scanning signal is high potential, and the second scanning signal is high potential, the 3rd scanning Signal is high potential, and the 4th scanning signal is low potential.

To sum up, OLED pixel drive circuit of the invention uses less TFT quantity (6), and numerous embodiments are eliminated Influences of the TFT threshold voltage vt h to light emitting diode is driven in OLED drive, Display panel uniformity is improved, and make The problems such as panel luminance reduction, luminous efficiency decline will not occur with the aging of OLED in panel.

Brief description of the drawings

Below in conjunction with the accompanying drawings, it is described in detail by the embodiment to the present invention, technical scheme will be made And other beneficial effects are apparent.

In accompanying drawing,

Fig. 1 a are existing OLED 2T1C pixel-driving circuit schematic diagrames;

Fig. 1 b are existing OLED 8T1C pixel compensation drive circuit schematic diagrams;

Fig. 1 c are the drive signal timing diagram of circuit shown in Fig. 1 b;

Fig. 1 d are existing OLED 7T1C pixel compensation drive circuit schematic diagrams;

Fig. 1 e are the drive signal timing diagram of circuit shown in Fig. 1 d;

Fig. 2 is the circuit and time diagram of the preferred embodiment of OLED pixel drive circuit first of the present invention;

Fig. 3 a illustrate for the first preferred embodiment of OLED pixel drive circuit current potential initial phase circuit state of the present invention It is intended to;

Fig. 3 b are the timing diagram of the first preferred embodiment current potential initial phase current driving signal;

Fig. 4 a are the first preferred embodiment Vdata-Vth memory phase circuit state figures;

Fig. 4 b are the timing diagram of the first preferred embodiment Vdata-Vth memory phase current driving signals;

Fig. 5 a are the first preferred embodiment luminescence display stage circuit state diagram;

Fig. 5 b are the timing diagram of the first preferred embodiment luminescence display stage circuit drive signal;

Fig. 6 is the circuit and time diagram of the preferred embodiment of OLED pixel drive circuit second of the present invention;

Fig. 7 is the circuit and time diagram of the preferred embodiment of OLED pixel drive circuit the 3rd of the present invention.

Embodiment

Referring to Fig. 2, it is the circuit and time diagram of the preferred embodiment of OLED pixel drive circuit first of the present invention.By In the source electrode and the characteristic of drain electrode of thin film transistor (TFT), do not distinguished specifically typically when describing structure of the present invention below.This hair Bright OLED pixel drive circuit mainly includes:Thin film transistor (TFT) T1, its grid connecting node g, source electrode and drain electrode are connected respectively Node s and node d, T1 exist as driving TFT in this circuit arrangement;Thin film transistor (TFT) T2, its grid connection scanning signal Scan1, source electrode and drain electrode difference connecting node g and node d;Thin film transistor (TFT) T3, its grid connection scanning signal Scan1, source Pole and drain electrode difference connecting node s and data voltage Vdata;Thin film transistor (TFT) T4, its grid connection scanning signal Scan2, source Pole and drain electrode difference connecting node g and ground GND;Thin film transistor (TFT) T5, its grid connection scanning signal Scan3, source electrode and drain electrode Power supply positive voltage OVDD and node S is connected respectively;Thin film transistor (TFT) T6, its grid connection scanning signal Scan3, source electrode and drain electrode Difference connecting node d and Organic Light Emitting Diode OLED anode;Organic Light Emitting Diode OLED negative electrode connection power supply negative electricity Press OVSS;Electric capacity C1, its one end connecting node g, other end connection power supply positive voltage OVDD;The sequential of scanning signal is configured to make Include three phases during the OLED pixel drive circuit works:Respectively current potential initial phase, Vdata-Vth memory phases, LED lighting shows the stage.Control thin film transistor (TFT) T4 is opened in the first stage, initializes node g current potential Vg to fixation Current potential;Node g current potential Vg is lifted in second stage, until Vg=data voltages Vdata- thin film transistor (TFT)s T1 threshold Threshold voltage;Start luminescence display in phase III Organic Light Emitting Diode OLED.Circuit for eliminating Vth is to light emitting diode Influence, improves Display panel uniformity.

With reference to Fig. 3 a~Fig. 5 b, the driving process of the first preferred embodiment is illustrated.

First stage:Current potential initial phase

As shown in Figure 3 a and Figure 3 b shows, Scan1, Scan3 are high potential, and T2, T3, T5, T6 is closed;Scan2 is low potential, T4 Open;

T4 is opened, and g point current potentials are discharged by T4, and Vg is to fixed potential for initialization, so that Vg=GND;

This stage completes the initialization of g point current potentials, and T6 is closed, and light emitting diode does not light.

Second stage:Vdata-Vth memory phases

As shown in figures 4 a and 4b, Scan2, Scan3 are high potential, and T4, T5, T6 is closed;Scan1 is low potential, T2, T3 Open;

T5 is closed, and T3 is opened, the current potential Vs=Vdata of s points;T2 is opened, T4, and T6 is closed, and g point current potentials pass through T2, T1, T3 Charged, ended when threshold voltage vt h of the cramping between s points and g points for driving TFT (T1), i.e. Vs-Vg= Vth, wherein Vs=Vdata, then have Vg=Vdata-Vth.This stage completes g point current potential Vdata-Vth storage, and T6 is closed, Light emitting diode does not light.

Phase III:The luminescence display stage

As shown in figure 5 a and 5b, Scan1, Scan2 are high potential, and T2, T3, T4 are closed;Scan3 is low potential, T5, T6 Open;

T2, T4 are closed, and g points current potential keeps Vg=Vdata-Vth constant;T3 is closed, and T5 is opened, s point current potentials Vs=OVDD; Cramping between s points and g points is now changed into Vsg=Vs-Vg=OVDD-(Vdata-Vth)=OVDD-Vdata+Vth;According to crystalline substance Body pipe I-V curve equation I=k (Vsg-Vth)2=k (OVDD-Vdata)2Understand the threshold voltage of electric current and driving TFT (T1) Vth is unrelated, eliminates influences of the threshold voltage vt h to light emitting diode, can improve the uniformity of Display panel, improves luminous effect Rate.

6T1C proposed by the invention OLED pixel drive circuit, for driving Organic Light Emitting Diode.When OLED is moved back When changing (Degradation), Vsg will not change, and Display panel brightness is not influenceed by OLED degradation, without extra power supply, compared with Few signal control line and better simply SECO.

Referring to Fig. 6, it is the circuit and time diagram of the preferred embodiment of OLED pixel drive circuit second of the present invention.The The drive circuit of two preferred embodiments is compared with the first preferred embodiment, although change T4 position, but T4 switch shape Whether state is still controlled initializes node g current potential Vg to fixed potential.

In second preferred embodiment, T2 in the first stage, T4, T6 is opened, and g points pass through T2, T4, T6 electric discharge, initialize Vg To fixed potential, so that Vg=GND, and VOLED=GND, diode does not light.

The second stage of second preferred embodiment and phase III are identical with the principle in the first preferred embodiment.

Referring to Fig. 7, it is the circuit and time diagram of the preferred embodiment of OLED pixel drive circuit the 3rd of the present invention.The The drive circuit of three preferred embodiments is compared with the first preferred embodiment, although change T4 position, but T4 switch shape Whether state is still controlled initializes node g current potential Vg to fixed potential.

3rd preferred embodiment kind, T3 in the first stage, T4 is opened, and g points are by T4, T3 discharge and recharges, and initialization Vg is to solid Determine current potential, so that Vg=Vini, this phase data line (data line) output fixed voltage Vini, that is, in the first stage Vdata=fixed voltages Vini.

The second stage of 3rd preferred embodiment and phase III are identical with the principle in the first preferred embodiment.

The present invention herein proposes three kinds of embodiments, and three kinds of embodiments have three phases, and difference is T4 position, leads to Cross change T4 position can just realize various ways eliminate Vth, but T4 purpose be provided to initialize g points current potential.

The OLED pixel drive circuit of the present invention uses less TFT quantity (6), can eliminate Vth to light-emitting diodes The influence of pipe, improves Display panel uniformity, improves luminous efficiency;Various ways can just be realized by only needing to change T4 position Vth is eliminated, implementation process principle is essentially identical;Using better simply timing control signal.

To sum up, OLED pixel drive circuit of the invention uses less TFT quantity (6), and numerous embodiments are eliminated Influences of the TFT threshold voltage vt h to light emitting diode is driven in OLED drive, Display panel uniformity is improved, and make The problems such as panel luminance reduction, luminous efficiency decline will not occur with the aging of OLED in panel.

It is described above, for the person of ordinary skill of the art, can be with technique according to the invention scheme and technology Other various corresponding changes and deformation are made in design, and all these changes and deformation should all belong to appended right of the invention It is required that protection domain.

Claims (12)

1. a kind of OLED pixel drive circuit, it is characterised in that including:
First film transistor (T1), its grid connection first node (g), source electrode and drain electrode respectively connection Section Point (s) and 3rd node (d);
Second thin film transistor (TFT) (T2), its grid connects the first scanning signal (Scan1), and source electrode and drain electrode connect first segment respectively Point (g) and the 3rd node (d);
3rd thin film transistor (TFT) (T3), its grid connects the first scanning signal (Scan1), and source electrode and drain electrode connect second section respectively Point (s) and data voltage (Vdata);
4th thin film transistor (TFT) (T4), its grid connects the second scanning signal (Scan2), and source electrode and drain electrode connect first segment respectively Point (g) and ground (GND);
5th thin film transistor (TFT) (T5), its grid connects the 3rd scanning signal (Scan3), and source electrode and drain electrode are connecting power supply just respectively Voltage (OVDD) and Section Point (S);
6th thin film transistor (TFT) (T6), its grid connects the 3rd scanning signal (Scan3), and source electrode and drain electrode connect Section three respectively The anode of point (d) and Organic Light Emitting Diode (OLED);
The negative electrode connection power supply negative voltage (OVSS) of Organic Light Emitting Diode (OLED);
Electric capacity (C1), its one end connection first node (g), other end connection power supply positive voltage (OVDD);
The sequential configuration of first scanning signal (Scan1), the second scanning signal (Scan2) and the 3rd scanning signal (Scan3) To make to include three phases during the OLED pixel drive circuit works:
Control the 4th thin film transistor (TFT) (T4) to open in the first stage, initialize the current potential (Vg) of the first node (g) to admittedly Determine current potential;
The current potential (Vg) of the first node (g) is lifted in second stage, until the current potential (Vg) of the first node (g)=data electricity Press the threshold voltage of (the Vdata)-first film transistor (T1);
In the phase III, the Organic Light Emitting Diode (OLED) starts luminescence display.
2. OLED pixel drive circuit as claimed in claim 1, it is characterised in that in the first stage, first scanning signal (Scan1) it is high potential, the second scanning signal (Scan2) is low potential, and the 3rd scanning signal (Scan3) is high potential, and this is consolidated It is ground (GND) to determine current potential.
3. OLED pixel drive circuit as claimed in claim 1, it is characterised in that in second stage, first scanning signal (Scan1) it is low potential, the second scanning signal (Scan2) is high potential, and the 3rd scanning signal (Scan3) is high potential.
4. OLED pixel drive circuit as claimed in claim 1, it is characterised in that in phase III, first scanning signal (Scan1) it is high potential, the second scanning signal (Scan2) is high potential, and the 3rd scanning signal (Scan3) is low potential.
5. a kind of OLED pixel drive circuit, it is characterised in that including:
First film transistor (T1), its grid connection first node (g), source electrode and drain electrode respectively connection Section Point (s) and 3rd node (d);
Second thin film transistor (TFT) (T2), its grid connects the first scanning signal (Scan1), and source electrode and drain electrode connect first segment respectively Point (g) and the 3rd node (d);
3rd thin film transistor (TFT) (T3), its grid connects the second scanning signal (Scan2), and source electrode and drain electrode connect second section respectively Point (s) and data voltage (Vdata);
4th thin film transistor (TFT) (T4), its grid connects the first scanning signal (Scan1), and source electrode and drain electrode are connected to machine hair The anode and ground (GND) of optical diode (OLED);
5th thin film transistor (TFT) (T5), its grid connects the 3rd scanning signal (Scan3), and source electrode and drain electrode are connecting power supply just respectively Voltage (OVDD) and Section Point (S);
6th thin film transistor (TFT) (T6), its grid connects the 4th scanning signal (Scan4), and source electrode and drain electrode connect Section three respectively The anode of point (d) and Organic Light Emitting Diode (OLED);
The negative electrode connection power supply negative voltage (OVSS) of Organic Light Emitting Diode (OLED);
Electric capacity (C1), its one end connection first node (g), other end connection power supply positive voltage (OVDD);
First scanning signal (Scan1), the second scanning signal (Scan2), the 3rd scanning signal (Scan3) and the 4th scanning letter The sequential of number (Scan4) is configured to make to include three phases during the OLED pixel drive circuit works:
Control the 4th thin film transistor (TFT) (T4) to open in the first stage, initialize the current potential (Vg) of the first node (g) to admittedly Determine current potential;
The current potential (Vg) of the first node (g) is lifted in second stage, until the current potential (Vg) of the first node (g)=data electricity Press the threshold voltage of (the Vdata)-first film transistor (T1);
In the phase III, the Organic Light Emitting Diode (OLED) starts luminescence display.
6. OLED pixel drive circuit as claimed in claim 5, it is characterised in that in the first stage, first scanning signal (Scan1) it is low potential, the second scanning signal (Scan2) is high potential, and the 3rd scanning signal (Scan3) is high potential, the 4th Scanning signal (Scan4) is low potential, and the fixed potential is ground (GND).
7. OLED pixel drive circuit as claimed in claim 5, it is characterised in that in second stage, first scanning signal (Scan1) it is low potential, the second scanning signal (Scan2) is low potential, and the 3rd scanning signal (Scan3) is high potential, the 4th Scanning signal (Scan4) is high potential.
8. OLED pixel drive circuit as claimed in claim 5, it is characterised in that in phase III, first scanning signal (Scan1) it is high potential, the second scanning signal (Scan2) is high potential, and the 3rd scanning signal (Scan3) is low potential, the 4th Scanning signal (Scan4) is low potential.
9. a kind of OLED pixel drive circuit, it is characterised in that including:
First film transistor (T1), its grid connection first node (g), source electrode and drain electrode respectively connection Section Point (s) and 3rd node (d);
Second thin film transistor (TFT) (T2), its grid connects the first scanning signal (Scan1), and source electrode and drain electrode connect first segment respectively Point (g) and the 3rd node (d);
3rd thin film transistor (TFT) (T3), its grid connects the second scanning signal (Scan2), and source electrode and drain electrode connect second section respectively Point (s) and data voltage (Vdata);
4th thin film transistor (TFT) (T4), its grid connects the 3rd scanning signal (Scan3), and source electrode and drain electrode connect first segment respectively Point (g) and Section Point (s);
5th thin film transistor (TFT) (T5), its grid connects the 4th scanning signal (Scan4), and source electrode and drain electrode are connecting power supply just respectively Voltage (OVDD) and Section Point (S);
6th thin film transistor (TFT) (T6), its grid connects the 4th scanning signal (Scan4), and source electrode and drain electrode connect Section three respectively The anode of point (d) and Organic Light Emitting Diode (OLED);
The negative electrode connection power supply negative voltage (OVSS) of Organic Light Emitting Diode (OLED);
Electric capacity (C1), its one end connection first node (g), other end connection power supply positive voltage (OVDD);
First scanning signal (Scan1), the second scanning signal (Scan2), the 3rd scanning signal (Scan3) and the 4th scanning letter The sequential of number (Scan4) is configured to make to include three phases during the OLED pixel drive circuit works:
Control the 4th thin film transistor (TFT) (T4) to open in the first stage, initialize the current potential (Vg) of the first node (g) to admittedly Determine current potential;
The current potential (Vg) of the first node (g) is lifted in second stage, until the current potential (Vg) of the first node (g)=data electricity Press the threshold voltage of (the Vdata)-first film transistor (T1);
In the phase III, the Organic Light Emitting Diode (OLED) starts luminescence display.
10. OLED pixel drive circuit as claimed in claim 9, it is characterised in that in the first stage, first scanning signal (Scan1) it is high potential, the second scanning signal (Scan2) is low potential, and the 3rd scanning signal (Scan3) is low potential, the 4th Scanning signal (Scan4) is high potential;The data voltage (Vdata) is fixed value (Vini), and the fixed potential is the fixed value (Vini)。
11. OLED pixel drive circuit as claimed in claim 9, it is characterised in that in second stage, first scanning signal (Scan1) it is low potential, the second scanning signal (Scan2) is low potential, and the 3rd scanning signal (Scan3) is high potential, the 4th Scanning signal (Scan4) is high potential.
12. OLED pixel drive circuit as claimed in claim 9, it is characterised in that in phase III, first scanning signal (Scan1) it is high potential, the second scanning signal (Scan2) is high potential, and the 3rd scanning signal (Scan3) is high potential, the 4th Scanning signal (Scan4) is low potential.
CN201710589084.0A 2017-07-19 2017-07-19 OLED pixel drive circuit CN107301844A (en)

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