CN106935201B - Pixel circuit and its driving method and active matrix/organic light emitting display - Google Patents

Pixel circuit and its driving method and active matrix/organic light emitting display Download PDF

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Publication number
CN106935201B
CN106935201B CN201511029763.XA CN201511029763A CN106935201B CN 106935201 B CN106935201 B CN 106935201B CN 201511029763 A CN201511029763 A CN 201511029763A CN 106935201 B CN106935201 B CN 106935201B
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transistor
organic light
light emitting
control
line
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CN201511029763.XA
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Chinese (zh)
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CN106935201A (en
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张九占
朱修剑
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昆山国显光电有限公司
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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]
    • G09G3/3225Control 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
    • G09G3/3233Control 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
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L27/00Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/28Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including components using organic materials as the active part, or using a combination of organic materials with other materials as the active part
    • H01L27/32Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including components using organic materials as the active part, or using a combination of organic materials with other materials as the active part with components specially adapted for light emission, e.g. flat-panel displays using organic light-emitting diodes [OLED]
    • H01L27/3241Matrix-type displays
    • H01L27/3244Active matrix displays

Abstract

In pixel circuit provided by the invention and its driving method and active matrix/organic light emitting display, the data voltage that the electric current that driving transistor is exported is provided by data line, the second source voltage that the threshold voltage and second source of Organic Light Emitting Diode provide determines, and it is unrelated with the first supply voltage that the threshold voltage of driving transistor and the first power supply provide, therefore it can be avoided the brightness disproportionation as caused by drive transistor threshold voltage deviation and IR pressure drop, simultaneously, the electric current that driving transistor is flowed through when the luminous efficiency of the Organic Light Emitting Diode reduces can increase automatically, so that the light emission luminance of the Organic Light Emitting Diode is basically unchanged, and then extend the service life of the active matrix/organic light emitting display.

Description

Pixel circuit and its driving method and active matrix/organic light emitting display

Technical field

The present invention relates to technical field of flat panel display, in particular to a kind of pixel circuit and its driving method and active matrix Organic light emitting display.

Background technique

Organic light emitting display utilizes Organic Light Emitting Diode (full name in English Organic Lighting Emitting Diode, abbreviation OLED) display image is a kind of display that active is luminous, display mode and traditional transistor liquid crystal are aobvious Show device (full name in English Thin Film Transistor liquid crystal display, abbreviation TFT-LCD) display mode Difference, be not necessarily to backlight, moreover, have contrast height, fast response time, it is frivolous many advantages, such as.Therefore, organic light emitting display Device is known as that the display of a new generation of transistor liquid crystal display (TFT-LCD) can be replaced.

According to the difference of driving method, organic light emitting display is divided into passive-matrix organic light emitting display (full name in English Passive Matrix Organic Lighting Emitting Display, abbreviation PMOLED) and the organic hair of active-matrix Optical display unit (full name in English Active Matrix Organic Lighting Emitting Display, abbreviation AMOLED), Active matrix organic light-emitting display is also referred to as active matrix/organic light emitting display.

Active matrix/organic light emitting display includes that scan line, data line and the scan line and data line are defined Pixel array, each pixel of the pixel array connects with corresponding scan line and data line.For example, being located at line n It is connect with the pixel of m column with the n-th scan line Sn and m data line Data.Referring to FIG. 1, it is the active of the prior art The structural schematic diagram of the pixel circuit of matrix organic light-emitting display.As shown in Figure 1, existing pixel circuit 10 includes that switch is brilliant Body pipe T1, driving transistor T2, storage capacitance Cs and Organic Light Emitting Diode OLED, the grid of the switching transistor T1 with sweep Line Sn connection is retouched, the source electrode of the switching transistor T1 is connect with data line Data, grid, the switch of the driving transistor T2 The drain electrode of transistor T1 and the first substrate of storage capacitance Cs are connected to node N1, the source electrode of the driving transistor T2 and storage The second substrate of capacitor Cs is connect with the first power supply ELVDD, the drain electrode of the driving transistor T2 and the organic light emission two The anode of pole pipe OLED connects, and the cathode of the Organic Light Emitting Diode OLED is connect with second source ELVSS.

By scan line Sn open the switching transistor T1 when, data line Data provide data voltage Vdata via The switching transistor T1 storage, so that controlling the driving transistor T2 generates electric current, drives transistor to storage capacitance Cs The driving current driving Organic Light Emitting Diode OLED of T2 output shines.At this point, flowing through the driving transistor T2 source electrode and leakage The calculation formula of electric current Ion between pole are as follows:

Ion=K × and (Vgs- | Vth |)2

Wherein, K is electron mobility, breadth length ratio, the product of unit-area capacitance three of transistor, and Vgs is driving crystal Voltage difference between the gate source voltage of pipe T2, i.e. grid and source electrode, Vth are the threshold voltage for driving transistor T2.

Since the source voltage Vs of driving transistor T2 is equal to the supply voltage VDD that the first power supply ELVDD is provided, driving is brilliant The grid voltage Vg of body pipe T2 is equal to the data voltage Vdata that data line Data is provided, therefore drives the grid source electricity of transistor T2 Vgs is pressed to be equal to VDD-Vdata.Flowing through the driving transistor T2 the current between the source and the drain Ion can be according to following public affairs Formula is calculated:

Ion=K × and (VDD-Vdata- | Vth |)2

It can be seen that the electric current for flowing through Organic Light Emitting Diode OLED will receive the threshold voltage vt h of driving transistor T2 With the influence for the supply voltage VDD for being applied to the pixel circuit, when driving transistor T2 threshold voltage vt h and supply voltage When VDD changes, the electric current for flowing through Organic Light Emitting Diode will have greatly changed, and lead to the organic light-emitting diodes Pipe OLED still launches the data-signal of same brightness the light of different brightness.

However, at present due to the limitation of manufacturing process, the transistor of each pixel in active matrix/organic light emitting display Threshold voltage be inevitably present difference, cause display brightness disproportionation phenomenon occur.Moreover, connecting the pixel circuit There are certain impedances for 10 power supply cabling, when electric current is by there is IR problem of pressure drop, the i.e. resistance of power supply cabling when power supply cabling Power supply electricity that is anti-to will affect the supply voltage VDD for being actually reached the pixel circuit 10, causing each pixel circuit 10 to receive It presses VDD inconsistent, and then aggravates brightness disproportionation phenomenon.Therefore, existing organic light emitting display is difficult display with uniformly bright The image of degree.

Especially since the length of power supply cabling increases with the increase of size of display panels, therefore between pixel Luminance deviation increases with the difference in length of power supply cabling.For large-sized active matrix/organic light emitting display, Power supply, which walks IR problem of pressure drop caused by line impedence, can become to be particularly acute, and display uneven phenomenon becomes apparent.

Base this, how to solve existing active matrix/organic light emitting display because driving transistor threshold voltage deviation with And IR pressure drop and caused by display problem, at those skilled in the art's technical problem urgently to be resolved.

Summary of the invention

The purpose of the present invention is to provide a kind of pixel circuit and its driving method and active matrix/organic light emitting display, It is caused with solving existing active matrix/organic light emitting display because driving the threshold voltage deviation and IR pressure drop of transistor Display problem.

To solve the above problems, the present invention provides a kind of pixel circuit, the pixel circuit includes:

Organic Light Emitting Diode is connected between the first power supply and second source;

The first transistor is connected between the first power supply and second node, and grid is connected to the second control line;

Second transistor is connected between first node and third node, and grid is connected to the second control line;

Third transistor is connected between second node and fourth node, and grid is connected to third node;

4th transistor is connected between third node and fourth node, and grid is connected to scan line;

5th transistor, is connected between data line and first node, and grid is connected to scan line;

6th transistor is connected between fourth node and the anode of Organic Light Emitting Diode, and grid is connected to first Control line;

Storage capacitance is connected between first node and second node.

Optionally, in the pixel circuit, first power supply and second source are used as the organic light-emitting diodes The driving power of pipe.

Optionally, in the pixel circuit, the first transistor to the 6th transistor is p-type film crystal Pipe.

Optionally, in the pixel circuit, the on and off of the first transistor and second transistor by The second control signal control that second control line provides, the on and off of the third transistor is by the third node Control of Electric potentials, the scanning signal that the on and off of the 4th transistor and the 5th transistor is provided by the scan line The on and off of control, the 6th transistor is controlled by the first control signal that first control line provides.

Optionally, in the pixel circuit, the third transistor is as driving transistor, the third transistor It is provided to the threshold value of data voltage, Organic Light Emitting Diode that the electric current of the Organic Light Emitting Diode provides by the data line The second source voltage that voltage and second source provide determines, and the first supply voltage for being provided with first power supply and The threshold voltage of third transistor is unrelated.

Correspondingly, the present invention also provides a kind of driving method of pixel circuit, the driving method packet of the pixel circuit Include: the scan period includes first time period, second time period and third period, wherein

In first time period, the scanning signal that scan line provides becomes low level from high level, what the first control line provided First control signal is high level, and the second control signal that the second control line provides is low level, opens the first transistor, second Data-signal is written in transistor, the 4th transistor and the 5th transistor;

It is low in the first control signal of scanning signal and the offer of the first control line that second time period, scan line provide Level, the second control signal that the second control line provides become high level from low level, open the 4th transistor, the 5th transistor With the first transistor and second transistor are closed while six transistors so that storage capacitance passes through third transistor, the 6th Transistor and Organic Light Emitting Diode discharge;

In the third period, the scanning signal that scan line provides is high level, the first control letter that the first control line provides Number and the second control signal that provides of the second control line be low level, it is brilliant to open the first transistor, second transistor and the 6th Body pipe, so that third transistor exports electric current and drives the organic light-emitting diode.

Optionally, in the driving method of the pixel circuit, the scan period further included the 4th period, described 4th period was set between the first time period and second time period;

In the 4th period, the second control signal that the scanning signal and the second control line that scan line provides provide is low Level, the first control signal that the first control line provides become low level from high level, open the 6th transistor.

Optionally, in the driving method of the pixel circuit, the scan period further included the 5th period, described 5th period was set between the second time period and third period;

In the 5th period, the scanning signal that scan line provides becomes high level from low level, what the first control line provided First control signal becomes low level from high level, and the second control signal that the second control line provides is high level, closes the 4th Transistor and the 5th transistor stop write-in data-signal.

Optionally, in the driving method of the pixel circuit, the scan period further included the 6th period, described 6th period was set between the third period and first time period;

In the 6th period, the scanning signal that scan line provides is high level, the first control letter that the first control line provides Number high level is become from low level, the second control signal that the second control line provides is low level, closes the 6th transistor, described Organic Light Emitting Diode stops shining.

Correspondingly, the present invention also provides a kind of active matrix/organic light emitting display, the active matrix organic light-emitting Display includes pixel circuit as described above.

In pixel circuit provided by the invention and its driving method and active matrix/organic light emitting display, crystal is driven The threshold voltage and second source of data voltage, Organic Light Emitting Diode that the electric current that pipe is exported is provided by data line provide Second source voltage determine, and with driving transistor threshold voltage and the first power supply provide the first supply voltage without It closes, therefore can be avoided the brightness disproportionation as caused by drive transistor threshold voltage deviation and IR pressure drop, meanwhile, have described The luminous efficiency of machine light emitting diode flows through driving transistor electric current when reducing can increase automatically, so that the organic light emission The light emission luminance of diode is basically unchanged, and then extends the service life of the active matrix/organic light emitting display.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of the pixel circuit of the active matrix/organic light emitting display of the prior art;

Fig. 2 is the structural schematic diagram of the pixel circuit of the embodiment of the present invention;

Fig. 3 is the timing diagram of the driving method of the pixel circuit of the embodiment of the present invention.

Specific embodiment

Below in conjunction with the drawings and specific embodiments to a kind of pixel circuit proposed by the present invention and its driving method and active Matrix organic light-emitting display is described in further detail.According to following explanation and claims, advantages of the present invention and spy Sign will become apparent from.It should be noted that attached drawing is all made of very simplified form and using non-accurate ratio, only to side Just, the purpose of the embodiment of the present invention is lucidly aided in illustrating.

Referring to FIG. 2, its structural schematic diagram for the pixel circuit of the embodiment of the present invention.As shown in Fig. 2, the pixel electricity Road 20 includes:

Organic Light Emitting Diode OLED is connected between the first power supply ELVDD and second source ELVSS;

The first transistor T1 is connected between the first power supply ELVDD and second node N2, and grid is connected to the second control Line Em;

Second transistor T2 is connected between first node N1 and third node N3, and grid is connected to the second control line Em;

Third transistor T3 is connected between second node N2 and fourth node N4, and grid is connected to third node N3;

4th transistor T4 is connected between third node N3 and fourth node N4, and grid is connected to scan line Sn;

5th transistor T5 is connected between data line Data and first node N1, and grid is connected to scan line Sn;

6th transistor T6 is connected between fourth node N4 and the anode of Organic Light Emitting Diode OLED, and grid connects It is connected to the first control line Em-1;

Storage capacitance C is connected between first node N1 and second node N2.

Specifically, the pixel circuit 20 and external power supply, including the first power supply ELVDD are connected with second source ELVSS. The first power supply ELVDD and second source ELVSS is used as the driving power of Organic Light Emitting Diode OLED.First power supply ELVDD is high potential pixel power, for providing the first supply voltage Vdd.The second source ELVSS is low potential pixel electricity Source, for providing second source voltage Vss.

With continued reference to FIG. 2, the pixel circuit 20 is a kind of 6T1C type circuit structure, including 6 transistors and 1 electricity Hold.Preferably, the first transistor T1 to the 6th transistor T6 is thin film transistor (TFT).The first transistor T1 to the 6th Transistor T6 can select P-type TFT, can also select N-type TFT.Well known, P-type TFT exists Grid signal is connected when being low level bit, and N-type TFT is connected when grid signal is high level position.It therefore, as long as will The transistor types and conducting current potential of selection match.

Wherein, the on and off of the first transistor T1 and second transistor T2 provided by the second control line Em second Control signal control, the control of Electric potentials of the on and off of third transistor T3 by third node N3, the 4th transistor T4 and the The on and off of five transistor T5 is controlled by the scanning signal that scan line Sn is provided, the on and off of the 6th transistor T6 The first control signal control provided by the first control line Em-1.

In the present embodiment, the first transistor T1 to the 6th transistor T6 is P-type TFT.As scan line Sn When the scanning signal of offer transits to low level, the 4th transistor T4 and the 5th transistor T5 are both turned on, and data line Data is provided Data-signal via the 5th transistor T5 be written first node N1.When the second control signal that the second control line Em is provided is low When level, the first transistor T1 and second transistor T2 are both turned on, the first supply voltage Vdd warp that the first power supply ELVDD is provided Second node N2 is applied to by the first transistor T1.When the first control signal that the first control line Em-1 is provided is low level, 6th transistor T6 conducting, the driving current of third transistor T3 output is along the first power supply ELVDD through the first transistor T1, third The path of transistor T3, the 6th transistor T6 and Organic Light Emitting Diode OLED flow to second source ELVSS, cause organic light emission Diode OLED lights luminous.

In the present embodiment, driving transistor of the third transistor T3 as pixel, the current potential corresponding to third node N3 comes Control provides the driving current for arriving the Organic Light Emitting Diode OLED, and the Organic Light Emitting Diode OLED is according to the driving Electric current issues the light of corresponding brightness, to show image.

Wherein, the driving current that third transistor T3 is provided to the Organic Light Emitting Diode OLED is mentioned by data line Data The second source that the data voltage Vdata of confession, the threshold voltage of Organic Light Emitting Diode OLED and second source ELVSS are provided Voltage Vss is determined, and the threshold voltage with the first power supply ELVDD the first supply voltage Vdd provided and third transistor T3 It is unrelated.Therefore, it can be avoided as caused by the threshold voltage deviation and IR pressure drop of transistor using the pixel circuit 20 Brightness disproportionation, and then improve the display quality of display.

Correspondingly, the present invention also provides a kind of driving methods of pixel circuit.Incorporated by reference to referring to figs. 2 and 3, the picture The driving method of plain circuit includes:

Scan period includes first time period t1, second time period t2 and third time period t 3;Wherein,

In first time period t1, the scanning signal that scan line Sn is provided becomes low level, the first control line Em- from high level 1 first control signal provided is high level, and the second control signal that the second control line Em is provided is low level, and it is brilliant to open first Data-signal is written in body pipe T1, second transistor T2, the 4th transistor T4 and the 5th transistor T5;

In the first control letter that second time period t2, scan line the Sn scanning signal provided and the first control line Em-1 provide It number is low level, the second control signal that the second control line Em is provided becomes high level from low level, opens the 4th transistor The first transistor T1 and second transistor T2 is closed while T4, the 5th transistor T5 and the 6th transistor T6, so that storage electricity Hold C to discharge by third transistor T3, the 6th transistor T6 and Organic Light Emitting Diode OLED;

In third time period t 3, the scanning signal that scan line Sn is provided is high level, the first control line Em-1 provide the The second control signal that one control signal and the second control line Em are provided is low level, opens the first transistor T1, the second crystalline substance Body pipe T2 and the 6th transistor T6, so that third transistor T3 exports electric current and the Organic Light Emitting Diode OLED is driven to send out Light.

Specifically, first time period t1 is data write phase.In first time period t1, since what scan line Sn was provided sweeps Retouching signal becomes low level from high level, and the 4th transistor T4 and the 5th transistor T5 controlled by scanning signal is become from ending First node N1 is written via the 5th transistor T5 in conducting, the data-signal that data line Data is provided, simultaneously because the second control The second control signal that line Em is provided is low level, the first transistor T1 and second transistor T2 controlled by second control signal In the conductive state, third section is written via the 5th transistor T5 and second transistor T2 in the data-signal that data line Data is provided Point N3, the first supply voltage Vdd that the first power supply ELVDD is provided are applied to second node N2 via the first transistor T1.

At this point, the current potential (i.e. the upper substrate current potential of storage capacitance C) of first node N1 is Vdata, the electricity of second node N2 Position (i.e. the lower substrate current potential of storage capacitance C) is Vdd.

Second time period t2 is the threshold voltage compensation stage.In second time period t2, the scanning provided due to scan line Sn The first control signal that signal and the first control line Em-1 are provided is low level, by retouch the 4th transistor T4 that signal control with 5th transistor T5 is in the conductive state, and the 6th transistor T6 controlled by first control signal is also on state, storage The lower substrate of capacitor C is discharged by third transistor T3, the 6th transistor T6 and Organic Light Emitting Diode OLED, until institute The conducting electric current for stating Organic Light Emitting Diode OLED is almost nil;

At the end of electric discharge, the anode voltage of the Organic Light Emitting Diode OLED is Voled (the i.e. described organic light-emitting diodes The sum of threshold voltage and second source voltage Vss of pipe OLED), second node N2 current potential is Voled+ | Vth |.Wherein, Vth is Drive the threshold voltage of transistor T3.The threshold voltage of transistor T3 is driven to be stored in storage capacitance C as a result,.

Simultaneously as the 5th transistor T5 is connected, the data voltage Vdata that data line data is provided is continued on through by the 5th crystalline substance Body pipe T5 is provided to first node N1, and the current potential of first node N1 is still Vdata.Therefore, the voltage difference etc. at the both ends storage capacitance C In Vdata-Voled- | Vth |.

Third time period t 3 is light emitting phase.In third time period t 3, the first control provided due to the first control line Em-1 The second control signal that signal processed and the second control line Em are provided is low level, the first crystal controlled by second control signal Pipe T1, second transistor T2 and the 6th transistor T6 controlled by first control signal are on state, third crystal Pipe T3 output electric current simultaneously drives the Organic Light Emitting Diode OLED to shine.

At this point, since the first transistor T1 is connected, the electricity of second node N2 (i.e. the lower substrate current potential of storage capacitance C) Position is by Voled+ | Vth | it jumps as Vdd.Due to the coupling of capacitor, the pressure difference of storage capacitance C upper and lower base plate is remained unchanged, Therefore the current potential (i.e. the upper substrate current potential of storage capacitance C) of first node N1 is Vdata+Vdd-Voled- | Vth |.

As it can be seen that the source voltage of third transistor T3 is equal to Vdd, the grid voltage of third transistor T3 is equal to first node The voltage of N1, i.e. Vdata+Vdd-Voled- | Vth |.Therefore, (the i.e. described third is brilliant by the gate source voltage Vgs of third transistor T3 Voltage difference between the grid and source electrode of body pipe T3) calculation formula are as follows:

Vgs=Vdd- (Vdata+Vdd-Voled- | Vth |) formula 1;

And flow through the calculation formula of the electric current Ioled of the Organic Light Emitting Diode OLED are as follows:

Ioled=K × and (Vgs- | Vth |)2Formula 2;

Wherein, K is electron mobility, breadth length ratio, the product of unit-area capacitance three of thin film transistor (TFT).

It can be obtained according to formula 1 and formula 2:

Ioled=K × (Voled-Vdata)2Formula 3;

Expression formula based on formula 3 is it is found that the electric current Ioled for flowing through the Organic Light Emitting Diode OLED is only electric with data Press Vdata, the threshold voltage of Organic Light Emitting Diode OLED, second source voltage Vss and constant K related, with the first power supply The threshold voltage vt h of voltage Vdd and third transistor T3 is not related.Even if because power line impedance causes the first supply voltage Vdd changes or deviation occurs in third transistor T3 threshold voltage vt h, will not be to flowing through the Organic Light Emitting Diode The electric current Ioled of OLED is impacted.Therefore, using the pixel circuit 20 and its driving method can be realized threshold voltage and The compensation of IR pressure drop avoids causing brightness disproportionation phenomenon due to threshold voltage deviation and power supply walk line impedence.

Moreover, when the luminous efficiency of the Organic Light Emitting Diode OLED reduces, i.e., the described Organic Light Emitting Diode When the anode voltage Voled of OLED is higher and higher with the extension of working time, the Organic Light Emitting Diode OLED is flowed through Electric current Ioled can increase and compensate automatically, so that it is guaranteed that the light emission luminance of the Organic Light Emitting Diode OLED is basic It is constant.

The pixel circuit 20 mainly realizes the compensation of threshold voltage and IR pressure drop by the work of three above period, To improve brightness uniformity.

With continued reference to FIG. 3, the scan period further includes the 4th time period t 4, the 5th time period t 5 and the 6th time period t 6. Wherein, the 4th time period t 4 is set between first time period t1 and second time period t2, and the 5th time period t 5 is set to second Between time period t 2 and third time period t 3, the 6th time period t 6 is set between third time period t 3 and first time period t1.

In the second control signal of scanning signal and the second control line Em offer that the 4th time period t 4, scan line Sn provide It is low level, the first control signal that the first control line Em-1 is provided becomes low level from high level, by first control signal 6th transistor T6 of control becomes being connected from ending.

In the 5th time period t 5, the scanning signal that scan line Sn is provided becomes high level, the first control line Em- from low level 1 first control signal provided becomes low level from high level, and the second control signal that the second control line Em is provided is high level, The 4th transistor T4 and the 5th transistor T5 controlled by scanning signal is become ending from conducting, since the 5th transistor T5 is cut Only, first node N1 can not be written in the data-signal that data line Data is provided via the 5th transistor T5, therefore stops write-in number It is believed that number.

In the 6th time period t 6, the scanning signal that scan line Sn is provided is high level, the first control line Em-1 provide the One control signal becomes high level from low level, and the second control signal that the second control line Em is provided is low level, by the first control 6th transistor T6 of signal control processed becomes ending from being connected, therefore the Organic Light Emitting Diode OLED stops shining.

Repeat first time period t1, the 4th time period t 4, second time period t2, the 5th time period t 5, third time period t 3 With the course of work of the 6th time period t 6, image display function is completed.

Correspondingly, the present invention also provides a kind of active matrix/organic light emitting display, the active matrix organic light-emitting Display includes pixel circuit 20 as described above.It specifically please refers to above, details are not described herein again.

It can be avoided simultaneously by driving using the active matrix/organic light emitting display of the pixel circuit and its driving method Various display problems caused by the threshold voltage deviation and IR pressure drop of dynamic transistor, and can be to Organic Light Emitting Diode The luminous efficiency of OLED compensates, therefore has higher brightness uniformity and longer service life.

To sum up, it in pixel circuit provided by the invention and its driving method and active matrix/organic light emitting display, drives The threshold voltage and the second electricity of data voltage, Organic Light Emitting Diode that the electric current that dynamic transistor is exported is provided by data line The first power supply electricity that the second source voltage that source provides is determined, and provided with the threshold voltage of driving transistor and the first power supply It presses unrelated, therefore can be avoided the brightness disproportionation as caused by drive transistor threshold voltage deviation and IR pressure drop, meanwhile, in institute Flowing through when stating the luminous efficiency reduction of Organic Light Emitting Diode drives the electric current of transistor that can increase automatically, so that described organic The light emission luminance of light emitting diode is basically unchanged, and then extends the service life of the active matrix/organic light emitting display.

Foregoing description is only the description to present pre-ferred embodiments, not to any restriction of the scope of the invention, this hair Any change, the modification that the those of ordinary skill in bright field does according to the disclosure above content, belong to the protection of claims Range.

Claims (10)

1. a kind of pixel circuit, comprising:
Organic Light Emitting Diode is connected between the first power supply and second source;
The first transistor is connected between the first power supply and second node, and grid is connected to the second control line;
Third transistor is connected between second node and fourth node;
6th transistor is connected between fourth node and the anode of Organic Light Emitting Diode, and grid is connected to the first control Line;
It is characterized by further comprising:
Second transistor is connected between first node and third node, and grid is connected to the second control line;
4th transistor is connected between third node and fourth node, and grid is connected to scan line;
5th transistor, is connected between data line and first node, and grid is connected to scan line;
Storage capacitance is connected between first node and second node;
Wherein, the grid of the third transistor is connected to the third node.
2. pixel circuit as described in claim 1, which is characterized in that first power supply and second source are as described organic The driving power of light emitting diode.
3. pixel circuit as described in claim 1, which is characterized in that the first transistor to the 6th transistor is p-type Thin film transistor (TFT).
4. pixel circuit as described in claim 1, which is characterized in that the conducting of the first transistor and second transistor and Cut-off is controlled by the second control signal that second control line provides, and the on and off of the third transistor is by described What the on and off of the control of Electric potentials of third node, the 4th transistor and the 5th transistor was provided by the scan line Scanning signal control, the first control signal control that the on and off of the 6th transistor is provided by first control line System.
5. pixel circuit as described in claim 1, which is characterized in that the third transistor is described as driving transistor Third transistor is provided to data voltage, the organic light emission two that the electric current of the Organic Light Emitting Diode is provided by the data line The first electricity that the second source voltage that the threshold voltage and second source of pole pipe provide is determined, and provided with first power supply Source voltage and the threshold voltage of third transistor are unrelated.
6. a kind of driving method of the pixel circuit as described in any one of claims 1 to 5, which is characterized in that the scan period Including first time period, second time period and third period, wherein
In first time period, scanning signal that scan line provides becomes low level from high level, the first control line provide first Control signal is high level, and the second control signal that the second control line provides is low level, opens the first transistor, the second crystal Data-signal is written in pipe, the 4th transistor and the 5th transistor;
It is low electricity in the first control signal of scanning signal and the offer of the first control line that second time period, scan line provide Flat, the second control signal that the second control line provides becomes high level from low level, open the 4th transistor, the 5th transistor and The first transistor and second transistor are closed while six transistors, so that storage capacitance passes through third transistor, the 6th crystalline substance Body pipe and Organic Light Emitting Diode discharge;
In the third period, scan line provide scanning signal be high level, the first control line provide first control signal and The second control signal that second control line provides is low level, opens the first transistor, second transistor and the 6th transistor, So that third transistor exports electric current and drives the organic light-emitting diode.
7. the driving method of pixel circuit as claimed in claim 6, which is characterized in that when the scan period further includes the 4th Between section, the 4th period is set between the first time period and second time period;
In the 4th period, the second control signal that the scanning signal and the second control line that scan line provides provide is low electricity Flat, the first control signal that the first control line provides becomes low level from high level, opens the 6th transistor.
8. the driving method of pixel circuit as claimed in claim 6, which is characterized in that when the scan period further includes the 5th Between section, the 5th period is set between the second time period and third period;
In the 5th period, the scanning signal that scan line provides becomes high level from low level, the first control line provide first Control signal becomes low level from high level, and the second control signal that the second control line provides is high level, closes the 4th crystal Pipe and the 5th transistor stop write-in data-signal.
9. the driving method of pixel circuit as claimed in claim 6, which is characterized in that when the scan period further includes the 6th Between section, the 6th period is set between the third period and first time period;
In the 6th period, scan line provide scanning signal be high level, the first control line provide first control signal by Low level becomes high level, and the second control signal that the second control line provides is low level, closes the 6th transistor, described organic Light emitting diode stops shining.
10. a kind of active matrix/organic light emitting display, which is characterized in that including as described in any one of claims 1 to 5 Pixel circuit.
CN201511029763.XA 2015-12-31 2015-12-31 Pixel circuit and its driving method and active matrix/organic light emitting display CN106935201B (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10490126B2 (en) 2017-07-25 2019-11-26 Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. Pixel compensation circuit
CN107437399B (en) * 2017-07-25 2019-03-22 武汉华星光电半导体显示技术有限公司 A kind of pixel compensation circuit
CN107731166A (en) * 2017-11-23 2018-02-23 武汉华星光电半导体显示技术有限公司 A kind of pixel-driving circuit, display device and terminal
CN107731169A (en) 2017-11-29 2018-02-23 京东方科技集团股份有限公司 A kind of OLED pixel circuit and its driving method, display device
CN108053792B (en) * 2018-01-19 2019-09-20 昆山国显光电有限公司 A kind of pixel circuit and its driving method, display device
CN108766355B (en) * 2018-06-01 2020-02-14 昆山国显光电有限公司 Pixel driving circuit, driving method, OLED display panel and device
CN110047440A (en) * 2019-05-23 2019-07-23 京东方科技集团股份有限公司 Pixel circuit, driving method, display panel and display device

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1776794A (en) * 2004-11-17 2006-05-24 Lg.菲利浦Lcd株式会社 Apparatus and method for driving organic light-emitting diode
CN104050916A (en) * 2014-06-04 2014-09-17 上海天马有机发光显示技术有限公司 Pixel compensating circuit for organic light-emitting display and method
CN104167170A (en) * 2014-07-10 2014-11-26 京东方科技集团股份有限公司 Pixel circuit and driving method thereof, and display device
CN104464630A (en) * 2014-12-23 2015-03-25 昆山国显光电有限公司 Pixel circuit, driving method of pixel circuit and active matrix organic light-emitting display
CN104575377A (en) * 2014-12-22 2015-04-29 昆山国显光电有限公司 Pixel circuit and driving method thereof as well as active matrix organic light emitting display
CN104835452A (en) * 2015-05-28 2015-08-12 京东方科技集团股份有限公司 Pixel circuit and driving method and related devices thereof
CN104867442A (en) * 2014-02-20 2015-08-26 北京大学深圳研究生院 Pixel circuit and display device

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1776794A (en) * 2004-11-17 2006-05-24 Lg.菲利浦Lcd株式会社 Apparatus and method for driving organic light-emitting diode
CN104867442A (en) * 2014-02-20 2015-08-26 北京大学深圳研究生院 Pixel circuit and display device
CN104050916A (en) * 2014-06-04 2014-09-17 上海天马有机发光显示技术有限公司 Pixel compensating circuit for organic light-emitting display and method
CN104167170A (en) * 2014-07-10 2014-11-26 京东方科技集团股份有限公司 Pixel circuit and driving method thereof, and display device
CN104575377A (en) * 2014-12-22 2015-04-29 昆山国显光电有限公司 Pixel circuit and driving method thereof as well as active matrix organic light emitting display
CN104464630A (en) * 2014-12-23 2015-03-25 昆山国显光电有限公司 Pixel circuit, driving method of pixel circuit and active matrix organic light-emitting display
CN104835452A (en) * 2015-05-28 2015-08-12 京东方科技集团股份有限公司 Pixel circuit and driving method and related devices thereof

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