CN110189698B - Pixel circuit, driving method thereof and display device - Google Patents
Pixel circuit, driving method thereof and display device Download PDFInfo
- Publication number
- CN110189698B CN110189698B CN201910579057.4A CN201910579057A CN110189698B CN 110189698 B CN110189698 B CN 110189698B CN 201910579057 A CN201910579057 A CN 201910579057A CN 110189698 B CN110189698 B CN 110189698B
- Authority
- CN
- China
- Prior art keywords
- circuit
- sub
- signal
- node
- terminal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
- G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
- G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
Abstract
The present disclosure relates to a pixel circuit, a driving method thereof, and a display device, wherein the pixel circuit includes: the drive sub-circuit, the data write-in sub-circuit, the compensation sub-circuit, the light-emitting control sub-circuit, the first energy storage sub-circuit and the second energy storage sub-circuit; the driving sub-circuit is respectively connected with a first power supply end, a first node and a second node; the data writing sub-circuit is used for responding to a first scanning signal and transmitting a data signal to the first node; a compensation sub-circuit for transmitting a first power supply signal to the first node in response to a compensation control signal; the light-emitting control sub-circuit is used for responding to a light-emitting control signal and transmitting a signal of the second node to the first end of the light-emitting element; a first tank sub-circuit connected between the first node and the second node; the second tank sub-circuit is connected between the first supply terminal and the second node.
Description
Technical Field
The disclosure relates to the technical field of display, and in particular relates to a pixel circuit, a driving method thereof and a display device.
Background
As the technology develops and advances, the OLED display device is increasingly used. The OLED display device generally drives a light emitting element to emit light through a pixel circuit, and the pixel circuit generates a driving current through a driving transistor.
In the manufacturing process of the display device, due to the influence of the manufacturing technology and the manufacturing process, it is not possible to ensure that all the parameters of the driving transistors are consistent, and thus, the technical parameters of different driving transistors, such as threshold voltage and mobility, are different. Due to the difference in threshold voltage drift and mobility, the current of different transistors is different, which causes non-uniform brightness of each light emitting device, and affects the display effect.
It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.
Disclosure of Invention
The present disclosure is directed to a pixel circuit, a driving method thereof, and a display device, so as to solve at least some of the problems of non-uniform brightness of each light emitting device and influence on display effect due to threshold voltage shift and mobility difference.
According to a first aspect of the present disclosure, there is provided a pixel circuit comprising:
the driving sub-circuit is respectively connected to the first power supply end, the first node and the second node;
the data writing sub-circuit is respectively connected with a data signal end, a first scanning signal end and the first node and is used for responding to a first scanning signal and transmitting a data signal to the first node;
a compensation sub-circuit, respectively connected to the first power terminal, the compensation control terminal and the first node, for transmitting a first power signal to the first node in response to a compensation control signal;
a light emitting control sub-circuit, respectively connected to the second node, the light emitting control terminal and the first terminal of the light emitting element, for transmitting a signal of the second node to the first terminal of the light emitting element in response to a light emitting control signal;
a first tank subcircuit connected between the first node and the second node;
a second tank subcircuit connected between the first power supply terminal and the second node.
According to an embodiment of the present disclosure, the pixel circuit further includes:
and the initialization sub-circuit is respectively connected with an initialization signal terminal, the first scanning signal terminal and the first terminal of the light-emitting element and is used for responding to the first scanning signal and transmitting the initialization signal to the first terminal of the light-emitting element.
According to an embodiment of the present disclosure, the driving sub-circuit includes:
and the first end of the driving transistor is connected to the first power supply end, the second end of the driving transistor is connected to the second node, and the control end of the driving transistor is connected to the first node.
According to an embodiment of the present disclosure, the data writing sub-circuit includes:
and the first end of the first transistor is connected to the data signal end, the second end of the first transistor is connected to the first node, and the control end of the first transistor is connected to the first scanning signal end and used for responding to the first scanning signal to be conducted so as to transmit the data signal to the first node.
According to an embodiment of the present disclosure, the compensation sub-circuit includes:
and a second transistor, having a first terminal connected to the first power terminal, a second terminal connected to the first node, and a control terminal connected to the compensation control terminal, and configured to be turned on in response to the compensation control signal so as to transmit the first power signal to the first node.
According to an embodiment of the present disclosure, the light emission control sub-circuit includes:
and a third transistor, having a first end connected to the second node, a second end connected to the first end of the light emitting element, and a control end connected to the light emission control end, and configured to be turned on in response to the light emission control signal, so as to transmit a signal of the first node to the first end of the light emitting element.
According to an embodiment of the present disclosure, the first tank sub-circuit includes:
a first energy storage capacitor connected between the first node and the second node;
the second tank sub-circuit comprises:
and the second energy storage capacitor is connected between the first power supply end and the second node.
According to an embodiment of the present disclosure, the initialization sub-circuit includes:
and a fourth transistor, having a first terminal connected to the initialization signal terminal, a second terminal connected to the first terminal of the light emitting element, and a control terminal connected to the first scan signal terminal, for turning on in response to the first scan signal to transmit the initialization signal to the first terminal of the light emitting element.
According to a second aspect of the present disclosure, there is provided a driving method of a pixel circuit for the above-mentioned pixel circuit, the driving method including:
switching on the data writing sub-circuit and switching off the compensation sub-circuit and the light emitting control sub-circuit by using the first scanning signal, the compensation control signal and the light emitting control signal so as to write the data signal into the first energy storage sub-circuit;
turning off the data writing sub-circuit, turning on the compensation sub-circuit, and turning off the light emission control sub-circuit to compensate the driving sub-circuit by the first power signal and the second tank sub-circuit, using the first scan signal, the compensation control signal, and the light emission control signal;
the data writing sub-circuit and the compensation sub-circuit are turned off and the light emission control sub-circuit is turned on by the first scan signal, the compensation control signal, and the light emission control signal to drive the light emitting element to emit light.
According to an embodiment of the present disclosure, when the pixel circuit further includes an initialization sub-circuit, the driving method further includes:
the data writing sub-circuit, the initialization sub-circuit, and the light emission control sub-circuit are turned on and the compensation sub-circuit is turned off using the first scan signal, the compensation control signal, and the light emission control signal to transmit an initialization signal to the first terminal and the second node of the light emitting element.
According to a third aspect of the present disclosure, there is provided a display device including the pixel circuit described above.
According to the pixel circuit provided by the disclosure, the driving sub-circuit is compensated through the compensation sub-circuit and the second energy storage sub-circuit, so that the influence of threshold voltage drift on driving current is eliminated, the problem that the brightness of a light-emitting element is not uniform due to inconsistent driving current caused by different transistor mobility is solved, and the display quality is improved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.
Drawings
The above and other features and advantages of the present disclosure will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.
Fig. 1 is a circuit diagram of a pixel circuit provided in an exemplary embodiment of the present disclosure;
fig. 2 is a circuit diagram of another pixel circuit provided in an exemplary embodiment of the present disclosure;
fig. 3 is a driving timing diagram of a pixel circuit according to an exemplary embodiment of the present disclosure;
fig. 4 is a flowchart of a driving method of a pixel circuit according to an exemplary embodiment of the present disclosure;
fig. 5 is a flowchart of another driving method of a pixel circuit according to an exemplary embodiment of the present disclosure.
In the figure:
100. a drive sub-circuit; 200. a data write sub-circuit; 300. a compensation sub-circuit; 400. a light emission control sub-circuit; 500. a first tank sub-circuit; 600. a second tank sub-circuit; 700. the sub-circuit is initialized.
Vdd, a first power supply signal; vss, second power supply signal; vdata, a data signal; sn, a first scanning signal; bn, a compensation control signal; EM, emission control signal; vint, initialization signal; DT, drive transistor; t1, a first transistor; t2, a second transistor; t3, a third transistor; t4, a fourth transistor; c1, a first energy storage capacitor; c2 and a second energy storage capacitor.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals denote the same or similar parts in the drawings, and thus, a repetitive description thereof will be omitted.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the embodiments of the disclosure can be practiced without one or more of the specific details, or with other methods, components, materials, devices, steps, and so forth. In other instances, well-known structures, methods, devices, implementations, materials, or operations are not shown or described in detail to avoid obscuring aspects of the disclosure.
The block diagrams shown in the figures are functional entities only and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in the form of software, or in one or more software-hardened modules, or in different networks and/or processor devices and/or microcontroller devices.
An exemplary embodiment of the present disclosure first provides a pixel circuit, as shown in fig. 1, including: the driving sub-circuit 100, the data writing sub-circuit 200, the compensation sub-circuit 300, the light-emitting control sub-circuit 400, the first energy-storing sub-circuit 500 and the second energy-storing sub-circuit 600; the driving sub-circuit 100 is respectively connected to a first power terminal, a first node N1 and a second node N2; the data writing sub-circuit 200 is respectively connected to a data signal terminal, a first scan signal Sn terminal, and the first node N1, and is configured to transmit a data signal Vdata to the first node N1 in response to the first scan signal Sn; the compensation sub-circuit 300 is respectively connected to the first power terminal, the compensation control terminal and the first node N1, and is used for transmitting a first power signal Vdd to the first node N1 in response to a compensation control signal Bn; the light emitting control sub-circuit 400 is respectively connected to the second node N2, a light emitting control terminal and a first terminal of a light emitting element, and is used for responding to a light emitting control signal EM to transmit a signal of the second node N2 to the first terminal of the light emitting element, and a second terminal of the light emitting element is connected to a second power supply signal Vss; the first tank sub-circuit 500 is connected between the first node N1 and the second node N2; the second tank circuit 600 is connected between said first supply terminal and said second node N2.
According to the pixel circuit provided by the embodiment of the disclosure, the compensation sub-circuit 300 and the second energy storage sub-circuit 600 compensate the driving sub-circuit 100, so that on one hand, data voltage, first power voltage and threshold voltage of a transistor are written into the energy storage sub-circuit, and influence of threshold voltage drift on driving current is eliminated; on the other hand, the problem that the brightness of the light-emitting element is not uniform due to inconsistent driving currents caused by different transistor mobility is solved, and the display quality is improved.
Further, the pixel circuit further includes an initialization sub-circuit 700, and the initialization sub-circuit 700 is respectively connected to an initialization signal terminal, the first scan signal Sn terminal, and the first terminal of the light emitting element, and is configured to transmit an initialization signal Vint to the first terminal of the light emitting element in response to the first scan signal Sn. The initialization sub-circuit 700 initializes the pixel circuit, thereby preventing the display device from generating the phenomena of afterimage or smear.
The following will explain each component of the pixel circuit provided by the present disclosure in detail:
as shown in fig. 2, the driving sub-circuit 100 includes a driving transistor DT, a first terminal of the driving transistor DT is connected to the first power source terminal, a second terminal of the driving transistor DT is connected to the second node N2, and a control terminal of the driving transistor DT is connected to the first node N1.
The data writing sub-circuit 200 includes a first transistor T1, a first terminal of the first transistor T1 is connected to the data signal terminal, a second terminal of the first transistor T1 is connected to the first node N1, a control terminal of the first transistor T1 is connected to the first scan signal Sn terminal, and the first transistor T1 is turned on in response to the first scan signal Sn to transmit the data signal Vdata to the first node N1.
The compensation sub-circuit 300 includes a second transistor T2, a first terminal of the second transistor T2 is connected to the first power source terminal, a second terminal of the second transistor T2 is connected to the first node N1, a control terminal of the second transistor T2 is connected to the compensation control terminal, and the second transistor T2 is configured to be turned on in response to the compensation control signal Bn to transmit the first power source signal Vdd to the first node N1.
The light emitting control sub-circuit 400 includes a third transistor T3, a first terminal of a third transistor T3 is connected to the second node N2, a second terminal of a third transistor T3 is connected to a first terminal of the light emitting device, a control terminal of the third transistor T3 is connected to the light emitting control terminal, and a third transistor T3 is turned on in response to the light emitting control signal EM to transmit the signal of the first node N1 to the first terminal of the light emitting device.
The first tank sub-circuit 500 comprises a first tank capacitor C1, a first tank capacitor C1 is connected between the first node N1 and the second node N2; the second energy storage sub-circuit 600 comprises a second energy storage capacitor C2, and a second energy storage capacitor C2 is connected between the first power supply terminal and the second node N2.
The initialization sub-circuit 700 includes a fourth transistor T4, a first terminal of the fourth transistor T4 is connected to the initialization signal terminal, a second terminal of the fourth transistor T4 is connected to the first terminal of the light emitting element, a control terminal of the fourth transistor T4 is connected to the first scan signal Sn terminal, and the fourth transistor T4 is turned on in response to the first scan signal Sn to transmit the initialization signal Vint to the first terminal of the light emitting element.
Each transistor provided in the embodiments of the present disclosure has a control terminal, a first terminal, and a second terminal. Specifically, the control terminal of each transistor may be a gate, the first terminal may be a source, and the second terminal may be a drain; alternatively, the control terminal of each transistor may be a gate, the first terminal may be a drain, and the second terminal may be a source. Further, each transistor may be an enhancement transistor or a depletion transistor, which is not particularly limited in this exemplary embodiment.
On the basis, all the transistors can be N-type thin film transistors, and the driving voltage of each transistor is high-level voltage; in this case, the first power signal Vdd may be a high level signal, the second power signal Vss may be a low level signal, the first terminal of the light emitting element is an anode of the OLED, and the second terminal of the light emitting element is a cathode of the OLED.
Or, all the transistors may be P-type thin film transistors, and the driving voltage of each transistor is a low level voltage; in this case, the first power signal Vdd may be a low level signal, the second power signal Vss may be a high level signal, the first terminal of the light emitting element is a cathode of the OLED, and the second terminal of the light emitting element is an anode of the OLED.
The operation of the pixel driving circuit in fig. 2 will be described in detail with reference to the timing chart shown in fig. 3. Taking all transistors as N-type transistors as an example, the first power signal Vdd is a high level signal, and the second power signal Vss is a low level signal; the light-emitting element is an organic light-emitting diode (OLED), the first end of the light-emitting element is the anode of the OLED, and the second end of the light-emitting element is the cathode of the OLED.
First period t1 (initialization phase): the emission control signal EM is at a high level, the first scan signal Sn is at a high level, the compensation control signal Bn is at a low level, the first transistor T1, the third transistor T3, the fourth transistor T4 and the driving transistor DT are turned on, the second transistor T2 is turned off, the voltage VN1 at the first node N1, the voltage VN2 at the second node N2, and the voltage VN3 at the third node N3 at the first end of the light emitting element. Wherein VN1 is Vdata; VN2 VN3 Vint.
Second period t2 (data writing phase): the emission control signal EM is at a low level, the first scan signal Sn is at a high level, the compensation control signal Bn is at a low level, the first transistor T1, the fourth transistor T4 and the driving transistor DT are turned on, the third transistor T3 and the second transistor T2 are turned off, the voltage VN1 of the first node N1, the voltage VN2 of the second node N2, and the voltage VN3 of the third node N3 at the first end of the light emitting element. Wherein VN1 is Vdata; VN2 is Vdata-Vth; VN3 ═ Vint.
Third period t3 (compensation phase): the emission control signal EM is at a low level, the first scan signal Sn is at a low level, the compensation control signal Bn is at a high level, the second transistor T2 and the driving transistor DT are turned on, the first transistor T1, the third transistor T3 and the fourth transistor T4 are turned off, the voltage VN1 at the first node N1, the voltage VN2 at the second node N2, and the voltage VN3 at the third node N3 at the first end of the light emitting element.
VN1 ═ Vdd;
VN3＝Vint。
at this time, the process of the present invention,
since Vdd > Vdata in general, and Vgd < Vth at this time, the driving transistor DT can be considered to be charged to the second node N2 in the compensation phase, and the charging time thereof is determined by the relative time of the rising edge and the falling edge of the compensation control signal Bn, i.e. the turn-on time of the second transistor T2, and at the end of data writing:
Vg＝Vdd；
wherein, δ V (μ)n) δ V (μ N) is determined by the on-time of the second transistor T2 and the μ value of the driving transistor DT as a function of the charging of the driving transistor DT to the second node N2. The turn-on time of the second transistor T2 includes the capacitively coupled write time of the first power signal Vdd and Δ V (μn) Rise time, hence δ V (μ)n) And munAnd (4) positively correlating.
Fourth period t4 (light emission period): the emission control signal EM is at a high level, the first scan signal Sn is at a low level, the compensation control signal Bn is at a low level, the third transistor T3 and the driving transistor DT are turned on, and the first transistor T1, the second transistor T2 and the fourth transistor T4 are turned off. At this time, although the potential of the second node N2 is influenced by the potential change of the first terminal of the light emitting element, the first node N1 is in a floating state, and thus the Vgs difference value based on the state of the second transistor T2 is not changed.
Therefore, the temperature of the molten metal is controlled,
the corresponding OLED currents are:
vdd is a first power signal, Vdata is a data signal, Vth is a threshold voltage of the driving transistor DT, Vint is an initialization signal, and μnTo drive the transistor DT mobility, COXThe voltage is an insulation capacitor in unit area, W/L is the width-to-length ratio of the driving transistor DT, C1 is a first energy storage capacitor, C2 is a second energy storage capacitor, and Vs is the source voltage of the driving transistor DT; vgs is the gate-source voltage of the driving transistor DT.
Due to COXW/L are constant, therefore, can make
k is a constant number, such that
V (n) at the same data voltage and first power supply voltage.
Therefore, IOLED＝kμn[V(n)-δV(μn)]2。
From the above formula, since δ V (. mu.) (n) And munPositive correlation when the drive transistor is in operationLow shift rate results in munLess than the target value, but- δ V (μ)n) Larger, which results in μ when the mobility of the drive transistor is highnGreater than target, but- δ V (μ)n) Smaller, so that IOLEDThe value of (A) is close to the target current value, so that the problem of nonuniform brightness of the light-emitting element caused by inconsistent driving current is solved to a certain extent, and the display quality is improved.
It should be noted that: in the above specific embodiment, all transistors are N-type transistors; those skilled in the art will readily appreciate that pixel drive circuits provided in accordance with the present disclosure have all transistors in the form of P-type transistors. In an exemplary embodiment of the present disclosure, all the transistors may be P-type transistors, where the first power signal Vdd is a low level signal, the cathode of the OLED is connected to the third transistor T3, and the anode of the OLED is connected to a high level signal. The adoption of the all-P type thin film transistor has the following advantages: for example, strong noise suppression; for example, low level is easy to realize in charge management because of low level conduction; for example, the P-type thin film transistor has simple manufacturing process and relatively low price; such as better stability of the P-type thin film transistor, etc. Of course, the pixel driving circuit provided in the present disclosure may also be replaced by a CMOS (Complementary Metal Oxide Semiconductor) circuit, etc., and is not limited to the pixel driving circuit provided in this embodiment, and will not be described herein again.
It should be noted that although in the above detailed description several sub-circuits of the pixel circuit are mentioned, this division is not mandatory. Indeed, the features and functions of two or more sub-circuits described above may be embodied in one sub-circuit, in accordance with embodiments of the present disclosure. Conversely, the features and functions of one sub-circuit described above may be further divided into embodiments by a plurality of sub-circuits.
According to the pixel circuit provided by the embodiment of the disclosure, the compensation sub-circuit 300 and the second energy storage sub-circuit 600 compensate the driving sub-circuit 100, so that on one hand, data voltage, first power voltage and threshold voltage of a transistor are written into the energy storage sub-circuit, and influence of threshold voltage drift on driving current is eliminated; on the other hand, the problem that the brightness of the light-emitting element is not uniform due to inconsistent driving currents caused by different transistor mobility is solved, and the display quality is improved.
The exemplary embodiment of the present disclosure also provides a driving method of a pixel circuit, which is used for the above-mentioned pixel circuit, and as shown in fig. 4, the driving method includes:
step S510, turning on the data writing sub-circuit 200 and turning off the compensation sub-circuit 300 and the light emission control sub-circuit 400 by using the first scan signal Sn, the compensation control signal Bn and the light emission control signal EM, so that the data signal Vdata is written into the first tank sub-circuit 500;
step S520, turning off the data writing sub-circuit 200, turning on the compensation sub-circuit 300, and turning off the emission control sub-circuit 400 by using the first scan signal Sn, the compensation control signal Bn, and the emission control signal EM to compensate the driving sub-circuit 100 by using the first power signal Vdd and the second energy storage sub-circuit 600;
in step S530, the data writing sub-circuit 200 and the compensation sub-circuit 300 are turned off and the light emission control sub-circuit 400 is turned on by using the first scan signal Sn, the compensation control signal Bn and the light emission control signal EM to drive the light emitting element to emit light.
According to the driving method of the pixel circuit provided by the embodiment of the disclosure, the compensation sub-circuit 300 and the second energy storage sub-circuit 600 compensate the driving sub-circuit 100, so that on one hand, the data voltage, the first power voltage and the threshold voltage of the transistor are written into the energy storage sub-circuit, and the influence of the threshold voltage drift on the driving current is eliminated; on the other hand, the problem that the brightness of the light-emitting element is not uniform due to inconsistent driving currents caused by different transistor mobility is solved, and the display quality is improved.
Further, when the pixel circuit further includes an initialization sub-circuit 700, as shown in fig. 5, the driving method further includes:
step S540 of turning on the data writing sub-circuit 200, the initialization sub-circuit 700, and the emission control sub-circuit 400 and turning off the compensation sub-circuit 300 by using the first scan signal Sn, the compensation control signal Bn, and the emission control signal EM to transmit an initialization signal Vint to the first terminal of the light emitting element and the second node N2.
When the driving sub-circuit 100 includes a driving transistor DT, the data writing sub-circuit 200 includes a first transistor T1, the compensation sub-circuit 300 includes a second transistor T2, the emission control sub-circuit 400 includes a third transistor T3, the initialization sub-circuit 700 includes a fourth transistor T4, the first energy storage sub-circuit 500 includes a first energy storage capacitor C1, and the second energy storage sub-circuit 600 includes a second energy storage capacitor C2, all the transistors are N-type transistors for example.
In step S540, the emission control signal EM is at a high level, the first scan signal Sn is at a high level, the compensation control signal Bn is at a low level, the first transistor T1, the third transistor T3, the fourth transistor T4 and the driving transistor DT are turned on, the second transistor T2 is turned off, the voltage VN1 of the first node N1, the voltage VN2 of the second node N2, and the voltage VN3 of the first end of the light emitting element and the third node N3. Wherein VN1 is Vdata; VN2 VN3 Vint.
In step S510, the emission control signal EM is at a low level, the first scan signal Sn is at a high level, the compensation control signal Bn is at a low level, the first transistor T1, the fourth transistor T4 and the driving transistor DT are turned on, the third transistor T3 and the second transistor T2 are turned off, the voltage VN1 at the first node N1, the voltage VN2 at the second node N2, and the voltage VN3 at the third node N3 at the first end of the light emitting element. Wherein VN1 is Vdata; VN2 is Vdata-Vth; VN3 ═ Vint.
In step S520, the emission control signal EM is at a low level, the first scan signal Sn is at a low level, the compensation control signal Bn is at a high level, the second transistor T2 and the driving transistor DT are turned on, the first transistor T1, the third transistor T3 and the fourth transistor T4 are turned off, the voltage VN1 of the first node N1, the voltage VN2 of the second node N2, and the voltage VN3 of the first end of the light emitting element and the third node N3.
VN1 ═ Vdd;
VN3＝Vint。
at this time, the process of the present invention,
since Vdd > Vdata in general, and Vgd < Vth at this time, the driving transistor DT can be considered to be charged to the second node N2 in the compensation phase, and the charging time thereof is determined by the relative time of the rising edge and the falling edge of the compensation control signal Bn, i.e. the turn-on time of the second transistor T2, and at the end of data writing:
Vg＝Vdd；
wherein, δ V (μ)n) δ V (μ) as a function of the charging of the drive transistor DT to the second node N2n) Determined by the on-time of the second transistor T2 and the value of μ of the driving transistor DT. The turn-on time of the second transistor T2 includes the capacitively coupled write time of the first power signal Vdd and Δ V (μn) Rise time, hence δ V (μ)n) And munAnd (4) positively correlating.
In step S530, the emission control signal EM is at a high level, the first scan signal Sn is at a low level, the compensation control signal Bn is at a low level, the third transistor T3 and the driving transistor DT are turned on, and the first transistor T1, the second transistor T2 and the fourth transistor T4 are turned off. At this time, although the potential of the second node N2 is influenced by the potential change of the first terminal of the light emitting element, the first node N1 is in a floating state, and thus the Vgs difference value based on the state of the second transistor T2 is not changed.
Therefore, the temperature of the molten metal is controlled,
the corresponding OLED currents are:
due to COXW/L are constant, therefore, can make
k is a constant number, such that
V (n) at the same data voltage and first power supply voltage.
Therefore, IOLED＝kμn[V(n)-δV(μn)]2。
From the above formula, since δ V (. mu.) (n) And munPositive correlation, which results when the mobility of the drive transistor is lownLess than the target value, but- δ V (μ)n) Larger, which results in μ when the mobility of the drive transistor is highnGreater than target, but- δ V (μ)n) Smaller, so that IOLEDThe value of (A) is close to the target current value, so that the problem of nonuniform brightness of the light-emitting element caused by inconsistent driving current is solved to a certain extent, and the display quality is improved.
Exemplary embodiments of the present disclosure also provide a display device including the pixel circuit described above. The display device includes: a plurality of scan lines for providing a first scan signal Sn; a plurality of data lines for supplying data signals Vdata; a plurality of compensation control signal Bn lines for providing compensation control signals Bn; a plurality of pixel driving circuits electrically connected to the scan lines, the data lines, and the compensation control signal Bn lines; at least one of the pixel driving circuits includes any of the pixel driving circuits described above in this exemplary embodiment. The driving sub-circuit 100 is compensated by the compensation sub-circuit 300 and the second energy storage sub-circuit 600, so that the influence of threshold voltage drift on the driving current is eliminated, the problem of nonuniform brightness of the light emitting element due to inconsistent driving current caused by different transistor mobility is solved, and the display quality is improved. The display device may include any product or component with a display function, such as a mobile phone, a tablet computer, a television, a notebook computer, a digital photo frame, and a navigator.
It should be noted that although the various steps of the methods of the present disclosure are depicted in the drawings in a particular order, this does not require or imply that these steps must be performed in this particular order, or that all of the depicted steps must be performed, to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions, etc.
Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is to be limited only by the terms of the appended claims.
Claims (10)
1. A pixel circuit, comprising:
a driving transistor connected to a first power terminal, a first node, and a second node, respectively;
the data writing sub-circuit is respectively connected with a data signal end, a first scanning signal end and the first node and is used for responding to a first scanning signal and transmitting a data signal to the first node;
a compensation sub-circuit, respectively connected to the first power terminal, the compensation control terminal and the first node, for transmitting a first power signal to the first node in response to a compensation control signal;
a light emitting control sub-circuit, respectively connected to the second node, the light emitting control terminal and the first terminal of the light emitting element, for transmitting a signal of the second node to the first terminal of the light emitting element in response to a light emitting control signal;
a first tank subcircuit connected between the first node and the second node;
a second tank sub-circuit connected between the first power supply terminal and the second node;
the first scanning signal, the compensation control signal and the light-emitting control signal are utilized to turn on the data writing sub-circuit and turn off the compensation sub-circuit and the light-emitting control sub-circuit in the data writing stage so as to write the data signal into the first energy storage sub-circuit; in the compensation stage, the data writing sub-circuit is turned off, the compensation sub-circuit is turned on, and the light-emitting control sub-circuit is turned off so as to compensate the mobility of the driving transistor through the first power supply signal and the second energy storage sub-circuit; and the data writing sub-circuit and the compensation sub-circuit are switched off in a light-emitting phase, the light-emitting control sub-circuit is switched on to drive the light-emitting element to emit light, and the compensation phase is after the data writing phase.
2. The pixel circuit of claim 1, wherein the pixel circuit further comprises:
and the initialization sub-circuit is respectively connected with an initialization signal terminal, the first scanning signal terminal and the first terminal of the light-emitting element and is used for responding to the first scanning signal and transmitting the initialization signal to the first terminal of the light-emitting element.
3. The pixel circuit according to claim 1, wherein the data writing sub-circuit comprises:
and the first end of the first transistor is connected to the data signal end, the second end of the first transistor is connected to the first node, and the control end of the first transistor is connected to the first scanning signal end and used for responding to the first scanning signal to be conducted so as to transmit the data signal to the first node.
4. The pixel circuit of claim 1, wherein the compensation sub-circuit comprises:
and a second transistor, having a first terminal connected to the first power terminal, a second terminal connected to the first node, and a control terminal connected to the compensation control terminal, and configured to be turned on in response to the compensation control signal so as to transmit the first power signal to the first node.
5. The pixel circuit of claim 1, wherein the light emission control sub-circuit comprises:
and a third transistor, having a first end connected to the second node, a second end connected to the first end of the light emitting element, and a control end connected to the light emission control end, and configured to be turned on in response to the light emission control signal, so as to transmit a signal of the second node to the first end of the light emitting element.
6. The pixel circuit of claim 1, wherein the first tank subcircuit comprises:
a first energy storage capacitor connected between the first node and the second node;
the second tank sub-circuit comprises:
and the second energy storage capacitor is connected between the first power supply end and the second node.
7. The pixel circuit of claim 2, wherein the initialization sub-circuit comprises:
and a fourth transistor, having a first terminal connected to the initialization signal terminal, a second terminal connected to the first terminal of the light emitting element, and a control terminal connected to the first scan signal terminal, for turning on in response to the first scan signal to transmit the initialization signal to the first terminal of the light emitting element.
8. A driving method of a pixel circuit, for use in the pixel circuit according to any one of claims 1 to 7, the driving method comprising:
switching on the data writing sub-circuit and switching off the compensation sub-circuit and the light emitting control sub-circuit by using the first scanning signal, the compensation control signal and the light emitting control signal so as to write the data signal into the first energy storage sub-circuit;
turning off the data writing sub-circuit, turning on the compensation sub-circuit, and turning off the light emission control sub-circuit using the first scan signal, the compensation control signal, and the light emission control signal to compensate for the mobility of the driving transistor by the first power signal and the second tank sub-circuit;
the data writing sub-circuit and the compensation sub-circuit are turned off and the light emission control sub-circuit is turned on by the first scan signal, the compensation control signal, and the light emission control signal to drive the light emitting element to emit light.
9. The driving method according to claim 8, wherein when the pixel circuit further includes an initialization sub-circuit, the driving method further includes:
the data writing sub-circuit, the initialization sub-circuit, and the light emission control sub-circuit are turned on and the compensation sub-circuit is turned off using the first scan signal, the compensation control signal, and the light emission control signal to transmit an initialization signal to the first terminal and the second node of the light emitting element.
10. A display device comprising the pixel circuit according to any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910579057.4A CN110189698B (en) | 2019-06-28 | 2019-06-28 | Pixel circuit, driving method thereof and display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910579057.4A CN110189698B (en) | 2019-06-28 | 2019-06-28 | Pixel circuit, driving method thereof and display device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110189698A CN110189698A (en) | 2019-08-30 |
| CN110189698B true CN110189698B (en) | 2021-04-13 |
Family
ID=67724307
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910579057.4A Active CN110189698B (en) | 2019-06-28 | 2019-06-28 | Pixel circuit, driving method thereof and display device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110189698B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI705428B (en) * | 2019-11-25 | 2020-09-21 | 友達光電股份有限公司 | Light-emitting diode apparatus and controlling method thereof |
| CN113053311A (en) * | 2021-03-23 | 2021-06-29 | 京东方科技集团股份有限公司 | Pixel circuit, driving method thereof and display device |
| CN114203109B (en) * | 2021-12-20 | 2022-12-13 | 长沙惠科光电有限公司 | Pixel driving circuit, compensation method thereof and display panel |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101075407A (en) * | 2006-05-18 | 2007-11-21 | Lg.菲利浦Lcd株式会社 | Pixel circuit of organic light emitting display |
| CN107316614A (en) * | 2017-08-22 | 2017-11-03 | 深圳市华星光电半导体显示技术有限公司 | AMOLED pixel-driving circuits |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008257086A (en) * | 2007-04-09 | 2008-10-23 | Sony Corp | Display device, manufacturing method of display device, and electronic equipment |
| KR100986896B1 (en) * | 2008-12-05 | 2010-10-08 | 삼성모바일디스플레이주식회사 | Organic Light Emitting Display Device and Driving Method Thereof |
| CN102005182A (en) * | 2010-11-18 | 2011-04-06 | 友达光电股份有限公司 | Driving circuit of pixel and method for driving pixel |
| CN103927990B (en) * | 2014-04-23 | 2016-09-14 | 上海天马有机发光显示技术有限公司 | The image element circuit of OLED and driving method, OLED |
| CN104200778B (en) * | 2014-09-25 | 2017-03-29 | 上海天马有机发光显示技术有限公司 | Image element circuit and its driving method, display floater, display device |
| CN108109590A (en) * | 2017-12-11 | 2018-06-01 | 京东方科技集团股份有限公司 | OLED pixel driving circuit, its driving method and include its display device |
| CN108597450A (en) * | 2018-04-26 | 2018-09-28 | 京东方科技集团股份有限公司 | Pixel circuit and its driving method, display panel |
| CN108806596A (en) * | 2018-06-26 | 2018-11-13 | 京东方科技集团股份有限公司 | Pixel-driving circuit and method, display device |
-
2019
- 2019-06-28 CN CN201910579057.4A patent/CN110189698B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101075407A (en) * | 2006-05-18 | 2007-11-21 | Lg.菲利浦Lcd株式会社 | Pixel circuit of organic light emitting display |
| CN107316614A (en) * | 2017-08-22 | 2017-11-03 | 深圳市华星光电半导体显示技术有限公司 | AMOLED pixel-driving circuits |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110189698A (en) | 2019-08-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10373555B2 (en) | Organic light emitting display panel, organic light emitting display device, and pixel compensation method | |
| CN109545145B (en) | Pixel circuit, driving method thereof and display device | |
| US11404001B2 (en) | Pixel driving circuit and method, display panel | |
| CN110136650B (en) | Pixel circuit, driving method thereof, array substrate and display device | |
| CN107945737B (en) | Pixel compensation circuit, driving method thereof, display panel and display device | |
| US11380256B2 (en) | Pixel driving circuit and method, and display device | |
| CN109887466B (en) | Pixel driving circuit and method and display panel | |
| WO2016161866A1 (en) | Pixel circuit, drive method therefor and display device | |
| CN109509428B (en) | Pixel driving circuit, pixel driving method and display device | |
| US20210142728A1 (en) | Pixel circuit, driving method thereof and display device | |
| CN109801592B (en) | Pixel circuit, driving method thereof and display substrate | |
| CN109509430B (en) | Pixel driving circuit and method and display device | |
| CN111540315B (en) | Pixel driving circuit, driving method thereof and display device | |
| CN110189698B (en) | Pixel circuit, driving method thereof and display device | |
| CN109064975B (en) | Pixel circuit, driving method thereof, display panel and display device | |
| CN110223639B (en) | Pixel circuit, pixel driving method, display substrate and display device | |
| TWI735338B (en) | Pixel driving circuit | |
| CN110010076B (en) | Pixel circuit, driving method thereof, display substrate and display device | |
| CN109712570B (en) | Pixel driving circuit, driving method thereof and display device | |
| US20200273406A1 (en) | Pixel driving circuit and method for driving the same, display panel, display apparatus | |
| CN113112964B (en) | Pixel circuit, pixel driving method and display device | |
| CN112908267B (en) | Pixel circuit, driving method and display device | |
| CN114898712B (en) | Pixel circuit, pixel driving method and display device | |
| KR20130002115A (en) | Driving circuit for organic light emitting diode display and method for driving the same | |
| CN114241978A (en) | Pixel circuit, driving method thereof and display panel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |