CN108288457A - Pixel circuit and its driving method, display device - Google Patents
Pixel circuit and its driving method, display device Download PDFInfo
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- CN108288457A CN108288457A CN201810055682.4A CN201810055682A CN108288457A CN 108288457 A CN108288457 A CN 108288457A CN 201810055682 A CN201810055682 A CN 201810055682A CN 108288457 A CN108288457 A CN 108288457A
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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]
- G09G3/3266—Details of drivers for scan electrodes
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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
- G09G3/3233—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 current through the light-emitting element
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
- Electroluminescent Light Sources (AREA)
- Control Of El Displays (AREA)
Abstract
The application discloses a kind of pixel circuit and its driving method, display device, the pixel circuit include：First film transistor, the second thin film transistor (TFT), third thin film transistor (TFT), the 4th thin film transistor (TFT), the 5th thin film transistor (TFT), the 6th thin film transistor (TFT), storage capacitance and light emitting diode.In the glow phase of the pixel circuit, when the pixel circuit is shown in dark-state, an only leakage path in pixel circuit, therefore, the grid voltage of driving thin film transistor (TFT) can be improved, the electric current that driving thin film transistor (TFT) generates is reduced, and then reduces the electric current for flowing through light emitting diode, in this way, due to when pixel circuit is shown in dark-state, the electric current for flowing through light emitting diode is reduced, it is thus possible to improve the contrast of display device.
Description
Technical field
This application involves display technology field more particularly to a kind of pixel circuit and its driving method, display devices.
Background technology
Organic light-emitting display device is a kind of display device using Organic Light Emitting Diode as luminescent device, have pair
Than spending the features such as high, thickness is thin, visual angle is wide, reaction speed is fast, low-power consumption, it is applied to each display and photograph more and more
Bright field.
In general, according to the difference of type of drive, organic light-emitting display device can be divided into active-matrix organic light emitting display
Device and passive-matrix organic light-emitting display device.Can include multiple pictures for active-matrix organic light emitting apparatus
Plain circuit, each pixel circuit can include driving thin film transistor (TFT), switching thin-film transistor, storage capacitance and light-emitting diodes
Pipe, wherein in the glow phase of pixel circuit, storage capacitance can act on driving thin film transistor (TFT) so that driving film is brilliant
Body pipe outputs current to light emitting diode, drives lumination of light emitting diode.
However, in practical applications, the driving thin film transistor (TFT) in pixel circuit is inevitably present leakage current, this
Sample, when pixel circuit is shown in dark-state, which can flow through light emitting diode so that light emitting diode sends out naked eyes can
The light distinguished reduces the contrast of organic light-emitting display device.
Invention content
A kind of pixel circuit of the embodiment of the present application offer and its driving method, display device, for solving existing display
In device, the relatively low problem of the contrast of display device caused by the leakage current due to driving thin film transistor (TFT).
The embodiment of the present application provides a kind of pixel circuit, including：First film transistor, the second thin film transistor (TFT), third
Thin film transistor (TFT), the 4th thin film transistor (TFT), the 5th thin film transistor (TFT), the 6th thin film transistor (TFT), storage capacitance and light-emitting diodes
Pipe, wherein：
The grid of the first film transistor respectively with one end of the storage capacitance and the third film crystal
The drain electrode of pipe connects, and the other end of the storage capacitance connects with the drain electrode of the 5th thin film transistor (TFT) and the first power supply respectively
It connects；
The drain electrode of the first film transistor respectively with the source electrode of the 5th thin film transistor (TFT) and described second thin
The drain electrode of film transistor connects, and the source electrode of second thin film transistor (TFT) is connect with data line；
The source electrode of the first film transistor is brilliant with the source electrode of the third thin film transistor (TFT), the 4th film respectively
The drain electrode of body pipe and the drain electrode of the 6th thin film transistor (TFT) connection, the source electrode and initial voltage of the 4th thin film transistor (TFT)
Signal wire connects, and the source electrode of the 6th thin film transistor (TFT) is connect with the anode of the light emitting diode, the light emitting diode
Cathode connect with second source.
Preferably, first power supply, for providing supply voltage for the first film transistor；
Electric current flows into the second source when lumination of light emitting diode.
Preferably, the initial voltage signal line provides initial voltage signal, and the initial voltage signal is negative voltage, is used
It is initialized in the grid and source electrode to the first film transistor.
Preferably, the grid of the 5th thin film transistor (TFT) and the grid of the 6th thin film transistor (TFT) and the first scanning
Line connects, and the first scanning signal that first scan line provides controls the 5th thin film transistor (TFT) and the 6th film
When transistor is in the conduction state, the lumination of light emitting diode；
The grid of the third thin film transistor (TFT) is connect with the second scan line, the second scanning that second scan line provides
When the signal control third thin film transistor (TFT) is in the conduction state, the threshold voltage of the first film transistor is mended
It repays；
The grid of 4th thin film transistor (TFT) is connect with third scan line, the third scanning that the third scan line provides
When signal control the 4th thin film transistor (TFT) is in the conduction state, grid and source electrode to the first film transistor carry out
Initialization；
The grid of second thin film transistor (TFT) is connect with the 4th scan line, the 4th scanning that the 4th scan line provides
When signal control second thin film transistor (TFT) is in the conduction state, the data voltage that the data line provides is thin to described first
The drain electrode of film transistor applies voltage.
Preferably, apply supply voltage, and the picture to the drain electrode of the first film transistor in first power supply
When plain circuit is shown in dark-state, the leakage current of the first film transistor flows into the third thin film transistor (TFT), improves institute
The grid voltage of first film transistor is stated, the contrast of the display device using the pixel circuit is increased.
Preferably, the first film transistor is P-type TFT；
Second thin film transistor (TFT), the third thin film transistor (TFT), the 4th thin film transistor (TFT), the 5th film
Transistor and the 6th thin film transistor (TFT) are N-type TFT or P-type TFT.
The embodiment of the present application provides a kind of driving method of pixel circuit, which is used to drive the institute of above-mentioned record
Pixel circuit is stated, which includes：
First stage, the first scanning signal controls the 5th thin film transistor (TFT) and the 6th thin film transistor (TFT) is in
Cut-off state, the second scanning signal control third thin film transistor (TFT) is in the conduction state, described in the control of third scanning signal
4th thin film transistor (TFT) is in the conduction state, and the 4th scanning signal controls second thin film transistor (TFT) and is in cut-off state, just
Beginning voltage signal initializes the grid and source electrode of the first film transistor；
Second stage, first scanning signal control the 5th thin film transistor (TFT) and the 6th thin film transistor (TFT)
In cut-off state, the second scanning signal control third thin film transistor (TFT) is in the conduction state, the third scanning
Signal controls the 4th thin film transistor (TFT) becomes cut-off state, the 4th scanning signal control described second from conducting state
Thin film transistor (TFT) becomes conducting state from cut-off state, is compensated to the threshold voltage of the first film transistor；
Phase III, first scanning signal control the 5th thin film transistor (TFT) and the 6th thin film transistor (TFT)
Conducting state is become from cut-off state, second scanning signal controls the third thin film transistor (TFT) to be become cutting from conducting state
Only state, the third scanning signal control the 4th thin film transistor (TFT) and are in cut-off state, the 4th scanning signal control
Make second thin film transistor (TFT) becomes cut-off state from conducting state, and electric current flows into the light emitting diode, described to shine two
Pole tube light-emitting.
Preferably, in the second stage, the drain voltage of the first film transistor is the data voltage, described
The grid voltage of first film transistor is Vdata-Vth, realizes the compensation to the threshold voltage of the first film transistor,
Wherein, Vdata is the data voltage, and Vth is the threshold voltage of the first film transistor.
Preferably, in the phase III, when the pixel circuit is shown in dark-state, the first film transistor
Leakage current flows into the third thin film transistor (TFT), improves the grid voltage of the first film transistor, increases and uses the picture
The contrast of the display device of plain circuit.
The embodiment of the present application also provides a kind of display device, which includes the pixel circuit of above-mentioned record.
Above-mentioned at least one technical solution that the embodiment of the present application uses can reach following advantageous effect：
Pixel circuit provided by the embodiments of the present application, in the glow phase of pixel circuit, at the pixel circuit display
When dark-state, there was only a leakage path in pixel circuit, it is thus possible to improve the grid voltage of driving thin film transistor (TFT), drop
The electric current that low driving thin film transistor (TFT) generates, and then the electric current for flowing through light emitting diode is reduced, in this way, due to aobvious in pixel circuit
When showing in dark-state, the electric current for flowing through light emitting diode is reduced, it is thus possible to improve the contrast of display device.
In addition to this, pixel circuit provided by the embodiments of the present application can also realize the threshold value to driving thin film transistor (TFT)
The compensation of voltage.
Description of the drawings
Attached drawing described herein is used for providing further understanding of the present application, constitutes part of this application, this Shen
Illustrative embodiments and their description please do not constitute the improper restriction to the application for explaining the application.In the accompanying drawings：
Fig. 1 is a kind of structural schematic diagram of pixel circuit in the prior art；
Fig. 2 is a kind of structural schematic diagram of pixel circuit provided by the embodiments of the present application；
Fig. 3 is a kind of sequence diagram of the driving method of pixel circuit provided by the embodiments of the present application；
Fig. 4 is that pixel circuit provided by the embodiments of the present application and pixel circuit in the prior art are in dark-state in display
The comparison diagram of the dark-state electric current of Shi Liujing light emitting diodes.
Specific implementation mode
In existing pixel circuit, when pixel circuit is shown in dark-state, for example, in completely black (0 grayscale) state, by
In the influence of the leakage current of driving thin film transistor (TFT) so that light emitting diode sends out the distinguishable light of naked eyes, causes to be susceptible to micro-
The phenomenon that bright spot.
For example, in pixel circuit shown in FIG. 1, in the glow phase of pixel circuit, when pixel circuit is shown in dark-state,
There are two leakage paths shown in FIG. 1, i.e. third thin film transistor (TFT) T33 and the 4th thin film transistor (TFT) T34 in pixel circuit
In there are leakage currents so that the voltage of N2 nodes reduces, that is, drives the grid voltage of thin film transistor (TFT) T31 to reduce, flow through driving
The electric current of thin film transistor (TFT) T31 increases, and then the electric current for flowing through light emitting diode EL31 increases, and leads in pixel circuit that there are micro-
The phenomenon that bright spot, reduces the contrast of display device.
Currently, typically each there are problems that leakage current in common pixel circuit, and leakage path is relatively more (at least
Two), the leakage current of every leakage path is also bigger, greatly reduces the contrast of display device.
In order to solve the above-mentioned problems in the prior art, the embodiment of the present application provides a kind of pixel circuit, and its drives
Dynamic method, display device, in the glow phase of the pixel circuit, when pixel circuit is shown in dark-state, in pixel circuit only
One leakage path, it is thus possible to improve the grid voltage of driving thin film transistor (TFT), reduces the electricity for flowing through driving thin film transistor (TFT)
Stream, and then the electric current for flowing through light emitting diode is reduced, in this way, due to when pixel circuit is shown in dark-state, reduces and flow through
Therefore the electric current of light emitting diode compared to existing technologies, can improve the contrast of display device.
Technical scheme is clearly and completely retouched with reference to the application specific embodiment and corresponding attached drawing
It states.Obviously, the described embodiments are only a part but not all of the embodiments of the present application.Based in the application
Embodiment, every other embodiment obtained by those of ordinary skill in the art without making creative efforts,
It shall fall in the protection scope of this application.
It should be noted that in pixel circuit provided by the embodiments of the present application, the first film transistor is driving
Thin film transistor (TFT) is specifically as follows P-type TFT；It is second thin film transistor (TFT), the third thin film transistor (TFT), described
4th thin film transistor (TFT), the 5th thin film transistor (TFT) and the 6th thin film transistor (TFT) can be p-type film crystal
Pipe, can also be is N-type TFT, can also be that wherein at least one is P-type TFT, remaining is N-type
Thin film transistor (TFT), the embodiment of the present application are not specifically limited.
The light emitting diode can be LED, can also be OLED, be also not specifically limited here.
Below in conjunction with attached drawing, the technical solution that each embodiment of the application provides is described in detail.
Embodiment 1
Fig. 2 is a kind of structural schematic diagram of pixel circuit provided by the embodiments of the present application.The pixel circuit is as described below.
As shown in Fig. 2, the pixel circuit includes first film transistor T1, the second thin film transistor (TFT) T2, third film
Transistor T3, the 4th thin film transistor (TFT) T4, the 5th thin film transistor (TFT) T5, the 6th thin film transistor (TFT) T6, storage capacitance Cst and hair
Optical diode D1.
Wherein, in pixel circuit shown in Fig. 2, first film transistor T1, the second thin film transistor (TFT) T2, third film are brilliant
Body pipe T3, the 4th thin film transistor (TFT) T4, the 5th thin film transistor (TFT) T5 and the 6th thin film transistor (TFT) T6 are p-type film crystal
Pipe, light emitting diode D1 are OLED.
The circuit connection structure of pixel circuit shown in Fig. 2 is as described below：
The leakage with one end of storage capacitance Cst and third thin film transistor (TFT) T3 respectively of the grid of first film transistor T1
Pole connects, and drain electrode is connect with the drain electrode of the source electrode of the 5th thin film transistor (TFT) T5 and the second thin film transistor (TFT) T2 respectively, source electrode point
Do not connect with the drain electrode of the source electrode, the 4th thin film transistor (TFT) T4 of third thin film transistor (TFT) T3 and the drain electrode of the 6th thin film transistor (TFT) T6
It connects；
The source electrode of second thin film transistor (TFT) T2 is connect with data line；
The source electrode of 4th thin film transistor (TFT) T4 is connect with initial voltage signal line；
The drain electrode of 5th thin film transistor (TFT) T5 is connect with the other end of storage capacitance Cst and the first power vd D respectively；
The source electrode of 6th thin film transistor (TFT) T6 is connect with the anode of light emitting diode D1；
The cathode of light emitting diode D1 is connect with second source VSS.
In the embodiment of the present application, the first power vd D can be high level voltage, and for being first film transistor
T1 provides supply voltage, and first film transistor T1, can be with output current under the action of the first power vd D, which flows into
Light emitting diode D1 so that light emitting diode D1 shines, and when light emitting diode D1 shines, which flows into second source VSS,
Second source VSS can be low level voltage.
The data line is for providing data voltage Vdata, and the initial voltage signal line is for providing initial voltage letter
Number Vinit.In the embodiment of the present application, initial voltage signal Vinit can be negative voltage, and for first film transistor T1
Grid and source electrode initialized.Wherein, as one kind, optionally mode, initial voltage signal Vinit can be -3V.
In Fig. 2, S1 is the first scanning signal that the first scan line provides, and S2 is the second scanning letter that the second scan line provides
Number, S3 is the third scanning signal that third scan line provides, and S4 is the 4th scanning signal that the 4th scan line provides, wherein：
The grid of 5th thin film transistor (TFT) T5 and the grid of the 6th thin film transistor (TFT) T6 are connect with the first scan line, and first
The first scanning signal S1 that scan line provides is in for control the 5th thin film transistor (TFT) T5 and the 6th thin film transistor (TFT) T6 and leads
Logical state or cut-off state；
The grid of third thin film transistor (TFT) T3 is connect with the second scan line, the second scanning signal S2 that the second scan line provides
For controlling, third thin film transistor (TFT) T3 is in the conduction state or cut-off state；
The grid of 4th thin film transistor (TFT) T4 is connect with third scan line, the third scanning signal S3 that third scan line provides
For controlling, the 4th thin film transistor (TFT) T4 is in the conduction state or cut-off state；
The grid of second thin film transistor (TFT) T2 is connect with the 4th scan line, the 4th scanning signal S4 that the 4th scan line provides
For controlling, the second thin film transistor (TFT) T2 is in the conduction state or cut-off state.
During the application is implemented, the 5th thin film transistor (TFT) T5 and the 6th thin film transistor (TFT) T6 is controlled in the first scanning signal S1
When in the conduction state, the first power vd D applies voltage to the drain electrode of first film transistor T1, and storage capacitance Cst is acted on
The grid of first film transistor T1 so that first film transistor T1 output currents, the electric current flow through light emitting diode D1, make
Light emitting diode D1 is obtained to shine.
When the second scanning signal S2 control third thin film transistor (TFT)s T3 is in the conduction state, first film transistor T1's
Grid is connect with source electrode, at this point, the data voltage Vdata that the data line provides can be to the drain electrode of first film transistor T1
Apply voltage, and charge to first film transistor T1, after charging, can make the leakage of first film transistor T1
Pole tension is Vdata, grid voltage Vdata-Vth, realizes the compensation to first film transistor T1 threshold voltages, wherein
Vth is the threshold voltage of first film transistor T1.
In addition, when the second scanning signal S2 control third thin film transistor (TFT)s T3 is in the conduction state, the 4th film crystal
Pipe T4 may be at conducting state, at this point, initial voltage signal Vinit can also pass through third thin film transistor (TFT) T3 and the 4th
Thin film transistor (TFT) T4, grid and storage Cst to first film transistor T1 initialize.
When the 4th thin film transistor (TFT) T4 of third scanning signal S3 controls is in the conduction state, the initial voltage signal line
The initial voltage signal Vinit of offer can initialize the source electrode of first film transistor T1.In the embodiment of the present application,
When the 4th thin film transistor (TFT) T4 is in the conduction state, third thin film transistor (TFT) T3 can also be in the conduction state, at this point, initially
Voltage signal Vinit can also initialize the grid and storage capacitance Cst of first film transistor T1.Initialization
Afterwards, the source voltage of first film transistor T1 and grid voltage are Vinit, and the bottom crown of storage capacitance Cst is (i.e. in Fig. 2
N points) voltage be equal to first film transistor T1 grid voltage, as Vinit.
The 4th scanning signal S4 control the second thin film transistor (TFT) T2 it is in the conduction state when, data voltage Vdata can be with
Apply voltage to the drain electrode of first film transistor T1, at this point, third thin film transistor (TFT) T3 may be at conducting state, in this way,
The compensation to the threshold voltage of first film transistor T1 can be realized according to the method for above-mentioned record.
Pixel circuit provided by the embodiments of the present application can also be improved using pixel electricity compared to existing technologies
The contrast of the display device on road, specifically includes：
When the first power vd D applies supply voltage to the drain electrode of first film transistor T1, the pixel circuit
Glow phase is may be at, if at this point, the pixel circuit, which is shown, is in dark-state, the leakage current of first film transistor T1 can
To flow into third thin film transistor (TFT) T3, in this way, due to compared to existing technologies, in the pixel circuit of the embodiment of the present application only
Have in third thin film transistor (TFT) T3 there are leakage current, reduce the leakage path in pixel circuit, i.e., leakage current only along T3,
T4, Vinit flow, it is thus possible to improve the grid voltage of first film transistor T1, reduces first film transistor T1 and generate
Electric current, and then reduce and flow through the electric current of light emitting diode D1, increase the contrast of the display device using the pixel circuit.
In short, pixel circuit provided by the embodiments of the present application, in the glow phase of pixel circuit, when the pixel circuit is shown
When in dark-state, there was only a leakage path in pixel circuit, it is thus possible to improve the grid voltage of driving thin film transistor (TFT),
The electric current that driving thin film transistor (TFT) generates is reduced, and then reduces the electric current for flowing through light emitting diode, in this way, due in pixel circuit
When display is in dark-state, the electric current for flowing through light emitting diode is reduced, it is thus possible to improve the contrast of display device.
In addition to this, in addition to this, pixel circuit provided by the embodiments of the present application can also be realized to driving film crystal
The compensation of the threshold voltage of pipe.
Embodiment 2
Fig. 3 is a kind of sequence diagram of the driving method of pixel circuit provided by the embodiments of the present application, and the sequence diagram corresponds to
The driving method of pixel circuit can be used for driving pixel circuit shown in Fig. 2.
The driving method of the corresponding pixel circuit of sequence diagram shown in Fig. 3 may include three phases：First stage t1,
Two-stage t2 and phase III t3, wherein S1 is the first scanning signal that the first scan line provides, and can be used for control figure 2
Shown in the 5th thin film transistor (TFT) T5 and the 6th thin film transistor (TFT) T6 is in the conduction state or cut-off state, S2 is the second scanning
Line provide the second scanning signal, can be used for controlling third thin film transistor (TFT) T3 shown in Fig. 2 it is in the conduction state or cut-off
State, S3 are the third scanning signal that third scan line provides, and can be used for controlling at the 4th thin film transistor (TFT) T4 shown in Fig. 2
In on state or off state, S4 is the 4th scanning signal that the 4th scan line provides, and can be used for controlling shown in Fig. 2 the
Two thin film transistor (TFT) T2 are in the conduction state or cut-off state, Vdata are the data voltage that data line provides.
The driving method of the corresponding pixel circuit of sequence diagram shown in Fig. 3, specifically includes：
First stage t1, the first scanning signal S1 controls the 5th thin film transistor (TFT) T5 and the 6th thin film transistor (TFT) T6 are in
Cut-off state, the second scanning signal S2 control third thin film transistor (TFT) T3 is in the conduction state, third scanning signal S3 controls the
Four thin film transistor (TFT) T4 are in the conduction state, and the 4th scanning signal S4 controls the second thin film transistor (TFT) T2 and is in cut-off state, just
Beginning voltage signal Vinit initializes the grid and source electrode of first film transistor T1；
Second stage t2, the first scanning signal S1 controls the 5th thin film transistor (TFT) T5 and the 6th thin film transistor (TFT) T6 are in
Cut-off state, the second scanning signal S2 control third thin film transistor (TFT) T3 is in the conduction state, third scanning signal S3 controls the
Four thin film transistor (TFT) T4 become cut-off state from conducting state, and the 4th scanning signal S4 controls the second thin film transistor (TFT) T2 by ending
State becomes conducting state, is compensated to the threshold voltage of first film transistor T1；
Phase III t3, the first scanning signal S1 control the 5th thin film transistor (TFT) T5 and the 6th thin film transistor (TFT) T6 are by cutting
Only state becomes conducting state, and the second scanning signal S2 controls third thin film transistor (TFT) T3 becomes cut-off state from conducting state,
Third scanning signal S3 controls the 4th thin film transistor (TFT) T4 and is in cut-off state, and the 4th scanning signal S4 controls the second film crystal
Pipe T2 becomes cut-off state from conducting state, and electric current flows into light emitting diode D1, and light emitting diode D1 shines.
It is made a concrete analysis of separately below for the above three stage：
For first stage t1：
Since the first scanning signal S1 keeps high level, the second scanning signal S2 to become low level from high level, third is swept
Retouch signal S3 becomes low level from high level, and the 4th scanning signal S4 keeps high level, therefore, the 5th thin film transistor (TFT) T5 and
6th thin film transistor (TFT) T6 is in cut-off state, and third thin film transistor (TFT) T3 is in the conduction state, the 4th thin film transistor (TFT) T4 by
Cut-off state becomes conducting state, and the second thin film transistor (TFT) T2 keeps cut-off state.
At this point, initial voltage signal Vinit is applied to the source of first film transistor T1 by the 4th thin film transistor (TFT) T4
Pole is applied to the grid of first film transistor T1 by the 4th thin film transistor (TFT) T4 and third thin film transistor (TFT) T3 and deposits
Storing up electricity holds Cst, the initialization to the grid and source electrode of first film transistor T1 may be implemented, and to storage capacitance Cst's
Initialization.
After initialization, the source voltage of first film transistor T1 and source voltage are equal to Vinit, storage capacitance Cst
Bottom crown voltage (voltage of N points shown in Fig. 2) also be Vinit.
For second stage t2：
Since the first scanning signal S1 keeps high level, the second scanning signal S2 to keep low level, third scanning signal S3
High level is become from low level, the 4th scanning signal S4 becomes low level from high level, therefore, the 5th thin film transistor (TFT) T5 and
6th thin film transistor (TFT) T6 is still in cut-off state, and third thin film transistor (TFT) T3 is still in conducting state, the 4th thin film transistor (TFT)
T4 becomes cut-off state from conducting state, and the second thin film transistor (TFT) T2 becomes conducting state from cut-off state.
At this point, the grid of first film transistor T1 is connect with source electrode, data voltage Vdata is to first film transistor T1
Drain electrode apply voltage, and charge to first film transistor T1, after charging, the drain electrode of first film transistor T1
Voltage is Vdata, grid voltage Vdata-Vth, in this manner it is achieved that the benefit of first film transistor T1 threshold voltages
It repays, wherein Vth is the threshold voltage of first film transistor T1.
For phase III t3：
Since the first scanning signal S1 becomes low level from high level, the second scanning signal S2 becomes high electricity from low level
Flat, third scanning signal S3 keeps high level, the 4th scanning signal S4 to become high level from low level, and therefore, the 5th film is brilliant
Body pipe T5 and the 6th thin film transistor (TFT) T6 becomes conducting state from cut-off state, and third thin film transistor (TFT) T3 is become by conducting state
For cut-off state, the 4th thin film transistor (TFT) T4 is become ending still in cut-off state, the second thin film transistor (TFT) T2 from conducting state
State.
At this point, the first power vd D applies voltage to the drain electrode of first film transistor T1, storage capacitance Cst acts on the
The grid of one thin film transistor (TFT) T1 so that first film transistor T1 generates grayscale electric current, which flows into light emitting diode D1,
So that light emitting diode D1 shines, wherein the electric current can be expressed as：
Wherein, μ is the electron mobility of first film transistor T1, CoxFor the grid of first film transistor T1 unit areas
Layer capacitance is aoxidized, W/L is the breadth length ratio of first film transistor T1.
As shown from the above formula, flow through the threshold voltage of the electric current of light emitting diode D1 and first film transistor T1 without
It closes, realizes the compensation of the threshold voltage to first film transistor T1.
In the embodiment of the present application, in phase III t3, when the pixel circuit is shown in dark-state, the first film crystal
The leakage current of pipe T1 flows into third thin film transistor (TFT) T3, i.e. leakage current is flowed only along T3, T4, Vinit, in this way, compared to existing
For having technology, since there are leakage currents in only third thin film transistor (TFT) T3 in the pixel circuit, reduce in pixel circuit
Leakage path reduce what first film transistor T1 was generated it is thus possible to improve the grid voltage of first film transistor T1
Electric current, and then the electric current for flowing through light emitting diode D1 is reduced, increase the contrast of the display device using the pixel circuit.
Fig. 4 is that pixel circuit provided by the embodiments of the present application and pixel circuit in the prior art are in dark-state in display
The comparison diagram of the dark-state electric current of Shi Liujing light emitting diodes.
In Fig. 4, black triangle label represent be in pixel circuit provided by the embodiments of the present application data voltage 0 to
When changing between 6V, pixel circuit flows through the dark-state electric current of light emitting diode when showing in dark-state, and gray squares mark generation
For data voltage 0 to when changing between 6V, pixel circuit flows through hair when showing in dark-state in the pixel circuit shown in FIG. 1 of table
The dark-state electric current of optical diode, wherein the current unit of ordinate is Naan.
From fig. 4, it can be seen that pixel circuit provided by the embodiments of the present application flows through light-emitting diodes when display is in dark-state
The electric current of pipe is relatively low, therefore, can effectively improve the contrast of display device.
Embodiment 3
The embodiment of the present application also provides a kind of display device, and the display device may include the institute described in embodiment 1
State pixel circuit.
It will be understood by those skilled in the art that although the preferred embodiment of the application has been described, skill in the art
Art personnel once know basic creative concept, then additional changes and modifications may be made to these embodiments.So appended
Claim, which is intended to be construed to, to be included preferred embodiment and falls into all change and modification of the application range.
Obviously, those skilled in the art can carry out the application model of the various modification and variations without departing from the application
It encloses.In this way, if these modifications and variations of the application belong within the scope of the application claim and its equivalent technologies, then
The application is also intended to include these modifications and variations.
Claims (10)
1. a kind of pixel circuit, which is characterized in that including：First film transistor, the second thin film transistor (TFT), third film crystal
Pipe, the 4th thin film transistor (TFT), the 5th thin film transistor (TFT), the 6th thin film transistor (TFT), storage capacitance and light emitting diode, wherein：
The grid of the first film transistor respectively with one end of the storage capacitance and the third thin film transistor (TFT)
Drain electrode connection, the other end of the storage capacitance are connect with the drain electrode of the 5th thin film transistor (TFT) and the first power supply respectively；
The drain electrode of the first film transistor is brilliant with the source electrode of the 5th thin film transistor (TFT) and second film respectively
The drain electrode of body pipe connects, and the source electrode of second thin film transistor (TFT) is connect with data line；
The source electrode of the first film transistor respectively with the source electrode of the third thin film transistor (TFT), the 4th thin film transistor (TFT)
Drain electrode and the 6th thin film transistor (TFT) drain electrode connection, the source electrode and initial voltage signal of the 4th thin film transistor (TFT)
Line connects, and the source electrode of the 6th thin film transistor (TFT) is connect with the anode of the light emitting diode, the moon of the light emitting diode
Pole is connect with second source.
2. pixel circuit as described in claim 1, which is characterized in that
First power supply, for providing supply voltage for the first film transistor；
Electric current flows into the second source when lumination of light emitting diode.
3. pixel circuit as claimed in claim 2, which is characterized in that
The initial voltage signal line provides initial voltage signal, and the initial voltage signal is negative voltage, for described the
The grid and source electrode of one thin film transistor (TFT) are initialized.
4. pixel circuit as claimed in claim 3, which is characterized in that
The grid of 5th thin film transistor (TFT) and the grid of the 6th thin film transistor (TFT) are connect with the first scan line, described
The first scanning signal that first scan line provides controls the 5th thin film transistor (TFT) and the 6th thin film transistor (TFT) is in
When conducting state, the lumination of light emitting diode；
The grid of the third thin film transistor (TFT) is connect with the second scan line, the second scanning signal that second scan line provides
Control the third thin film transistor (TFT) it is in the conduction state when, the threshold voltage of the first film transistor is compensated；
The grid of 4th thin film transistor (TFT) is connect with third scan line, the third scanning signal that the third scan line provides
Control the 4th thin film transistor (TFT) it is in the conduction state when, grid to the first film transistor and source electrode carry out initial
Change；
The grid of second thin film transistor (TFT) is connect with the 4th scan line, the 4th scanning signal that the 4th scan line provides
Control second thin film transistor (TFT) it is in the conduction state when, data voltage that the data line provides is to the first film crystalline substance
The drain electrode of body pipe applies voltage.
5. pixel circuit as claimed in claim 4, which is characterized in that
Apply supply voltage to the drain electrode of the first film transistor in first power supply, the pixel circuit, which is shown, to be in
When dark-state, the leakage current of the first film transistor flows into the third thin film transistor (TFT), improves the first film crystal
The grid voltage of pipe increases the contrast of the display device using the pixel circuit.
6. the pixel circuit as described in claim 1 to 5, which is characterized in that
The first film transistor is P-type TFT；
Second thin film transistor (TFT), the third thin film transistor (TFT), the 4th thin film transistor (TFT), the 5th film crystal
Pipe and the 6th thin film transistor (TFT) are N-type TFT or P-type TFT.
7. a kind of driving method of such as claim 1 to 6 any one of them pixel circuit, which is characterized in that including：
First stage, the first scanning signal controls the 5th thin film transistor (TFT) and the 6th thin film transistor (TFT) is in cut-off
State, the second scanning signal control third thin film transistor (TFT) is in the conduction state, third scanning signal control the described 4th
Thin film transistor (TFT) is in the conduction state, and the 4th scanning signal controls second thin film transistor (TFT) and is in cut-off state, initial electricity
Pressure signal initializes the grid and source electrode of the first film transistor；
Second stage, first scanning signal controls the 5th thin film transistor (TFT) and the 6th thin film transistor (TFT) is in
Cut-off state, the second scanning signal control third thin film transistor (TFT) is in the conduction state, the third scanning signal
Control the 4th thin film transistor (TFT) becomes cut-off state from conducting state, and the 4th scanning signal controls second film
Transistor becomes conducting state from cut-off state, is compensated to the threshold voltage of the first film transistor；
Phase III, first scanning signal control the 5th thin film transistor (TFT) and the 6th thin film transistor (TFT) by cutting
Only state becomes conducting state, and second scanning signal, which controls the third thin film transistor (TFT), to be become ending shape from conducting state
State, the third scanning signal control the 4th thin film transistor (TFT) and are in cut-off state, and the 4th scanning signal controls institute
State the second thin film transistor (TFT) becomes cut-off state from conducting state, and electric current flows into the light emitting diode, the light emitting diode
It shines.
8. the driving method of pixel circuit as claimed in claim 7, which is characterized in that
It is the data voltage in the drain voltage of the second stage, the first film transistor, the first film is brilliant
The grid voltage of body pipe is Vdata-Vth, realizes the compensation to the threshold voltage of the first film transistor, wherein Vdata
For the data voltage, Vth is the threshold voltage of the first film transistor.
9. the driving method of pixel circuit as claimed in claim 7, which is characterized in that
In the phase III, when the pixel circuit is shown in dark-state, the leakage current of the first film transistor flows into
The third thin film transistor (TFT) improves the grid voltage of the first film transistor, increases using the aobvious of the pixel circuit
The contrast of showing device.
10. a kind of display device, which is characterized in that including：Such as claim 1 to 6 any one of them pixel circuit.
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| CN201810055682.4A CN108288457A (en) | 2018-01-19 | 2018-01-19 | Pixel circuit and its driving method, display device |
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| CN201810055682.4A CN108288457A (en) | 2018-01-19 | 2018-01-19 | Pixel circuit and its driving method, display device |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109215585A (en) * | 2018-11-26 | 2019-01-15 | 京东方科技集团股份有限公司 | Pixel circuit and its driving method and display device |
| CN110223640A (en) * | 2019-06-26 | 2019-09-10 | 昆山国显光电有限公司 | A kind of pixel-driving circuit and display device |
| CN111243526A (en) * | 2020-01-19 | 2020-06-05 | 京东方科技集团股份有限公司 | Pixel circuit, display device and driving method |
| WO2020220613A1 (en) * | 2019-04-29 | 2020-11-05 | 云谷（固安）科技有限公司 | Pixel drive circuit and drive method therefor |
| WO2022016722A1 (en) * | 2020-07-24 | 2022-01-27 | 武汉华星光电半导体显示技术有限公司 | Pixel circuit and driving method therefor |
| CN114120881A (en) * | 2021-12-13 | 2022-03-01 | 武汉华星光电半导体显示技术有限公司 | Pixel circuit, display device and driving method thereof |
| WO2023185740A1 (en) * | 2022-04-02 | 2023-10-05 | 华为技术有限公司 | Driving circuit and display device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106448554A (en) * | 2016-11-30 | 2017-02-22 | 武汉华星光电技术有限公司 | OLED (organic light-emitting diode) driving circuit and OLED display panel |
| CN107123397A (en) * | 2017-06-14 | 2017-09-01 | 深圳市华星光电技术有限公司 | AMOLED pixel-driving circuits and image element driving method |
| CN107301842A (en) * | 2017-08-17 | 2017-10-27 | 深圳市华星光电半导体显示技术有限公司 | A kind of OLED pixel drive circuit and image element driving method |
| CN107331352A (en) * | 2017-08-16 | 2017-11-07 | 深圳市华星光电半导体显示技术有限公司 | A kind of OLED pixel drive circuit and image element driving method |
-
2018
- 2018-01-19 CN CN201810055682.4A patent/CN108288457A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106448554A (en) * | 2016-11-30 | 2017-02-22 | 武汉华星光电技术有限公司 | OLED (organic light-emitting diode) driving circuit and OLED display panel |
| CN107123397A (en) * | 2017-06-14 | 2017-09-01 | 深圳市华星光电技术有限公司 | AMOLED pixel-driving circuits and image element driving method |
| CN107331352A (en) * | 2017-08-16 | 2017-11-07 | 深圳市华星光电半导体显示技术有限公司 | A kind of OLED pixel drive circuit and image element driving method |
| CN107301842A (en) * | 2017-08-17 | 2017-10-27 | 深圳市华星光电半导体显示技术有限公司 | A kind of OLED pixel drive circuit and image element driving method |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109215585A (en) * | 2018-11-26 | 2019-01-15 | 京东方科技集团股份有限公司 | Pixel circuit and its driving method and display device |
| WO2020220613A1 (en) * | 2019-04-29 | 2020-11-05 | 云谷（固安）科技有限公司 | Pixel drive circuit and drive method therefor |
| CN110223640A (en) * | 2019-06-26 | 2019-09-10 | 昆山国显光电有限公司 | A kind of pixel-driving circuit and display device |
| CN111243526A (en) * | 2020-01-19 | 2020-06-05 | 京东方科技集团股份有限公司 | Pixel circuit, display device and driving method |
| US11830427B2 (en) | 2020-01-19 | 2023-11-28 | Ordos Yuansheng Optoelectronics Co., Ltd. | Pixel circuit, display apparatus and driving method |
| WO2022016722A1 (en) * | 2020-07-24 | 2022-01-27 | 武汉华星光电半导体显示技术有限公司 | Pixel circuit and driving method therefor |
| US11798461B2 (en) | 2020-07-24 | 2023-10-24 | Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. | Pixel circuit and driving method thereof |
| CN114120881A (en) * | 2021-12-13 | 2022-03-01 | 武汉华星光电半导体显示技术有限公司 | Pixel circuit, display device and driving method thereof |
| WO2023185740A1 (en) * | 2022-04-02 | 2023-10-05 | 华为技术有限公司 | Driving circuit and display device |
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