CN116486760A - Pixel circuit, driving method thereof and display panel - Google Patents

Pixel circuit, driving method thereof and display panel Download PDF

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Publication number
CN116486760A
CN116486760A CN202310245862.XA CN202310245862A CN116486760A CN 116486760 A CN116486760 A CN 116486760A CN 202310245862 A CN202310245862 A CN 202310245862A CN 116486760 A CN116486760 A CN 116486760A
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CN
China
Prior art keywords
module
pixel circuit
light
driving
voltage
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Pending
Application number
CN202310245862.XA
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Chinese (zh)
Inventor
郭子栋
程芸
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Yungu Guan Technology Co Ltd
Hefei Visionox Technology Co Ltd
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Yungu Guan Technology Co Ltd
Hefei Visionox Technology Co Ltd
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Application filed by Yungu Guan Technology Co Ltd, Hefei Visionox Technology Co Ltd filed Critical Yungu Guan Technology Co Ltd
Priority to CN202310245862.XA priority Critical patent/CN116486760A/en
Publication of CN116486760A publication Critical patent/CN116486760A/en
Pending legal-status Critical Current

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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
    • G09G5/36—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators characterised by the display of a graphic pattern, e.g. using an all-points-addressable [APA] memory
    • G09G5/39—Control of the bit-mapped memory
    • G09G5/393—Arrangements for updating the contents of the bit-mapped memory
    • 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
    • G09G3/2007—Display of intermediate tones
    • G09G3/2074—Display of intermediate tones using sub-pixels
    • 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]
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

The application discloses a pixel circuit and driving method thereof, display panel, this pixel circuit includes: the first end of the driving module is connected with a first voltage source; the second end of the adjustable capacitance module is connected with the control end of the driving module, and the first end of the adjustable capacitance module is connected with the second voltage source so as to adjust the capacitance value of the adjustable capacitance module according to the output voltage of the second voltage source; the first end of the light emitting module is connected with the second end of the driving module, and the second end of the light emitting module is connected with a third voltage source. By means of the mode, the pixel circuit can adjust the capacitance value of the adjustable capacitance module according to the output voltage of the second voltage source so as to use the output voltage of the second voltage source required by a low capacitance value in high-frequency display, and therefore the charging time of the adjustable capacitance module can be shortened, and the compensation effect is guaranteed; and the output voltage of the second voltage source required by the high capacity value is used during low-frequency display so as to ensure that the light-emitting module is stable in voltage and does not flicker.

Description

Pixel circuit, driving method thereof and display panel
Technical Field
The present disclosure relates to the field of display panels, and in particular, to a pixel circuit, a driving method thereof, and a display panel.
Background
Nowadays, with the continuous development of display technology, there is an increasing demand for increasing the refresh rate of the display panel, but the pixel circuit in the conventional display panel generally adopts a 7T1C (7 transistors and 1 capacitor) circuit, and since the capacitance of the charging capacitor Cst in the 7T1C circuit is generally fixed, the charging time is limited, so that when Vdata (data voltage signal) writing compensation is performed in the 7T1C circuit, there is a problem of insufficient compensation in high-frequency display, and a problem of flicker of the light emitting device caused by the inability of voltage stabilization in low-frequency display.
Disclosure of Invention
The technical problem that this application mainly solves is to provide a pixel circuit and drive method, display panel, can solve the pixel circuit among the prior art when high frequency display, has the problem of compensation inadequately, and when low frequency display, has again and can not stabilize voltage and lead to the problem that luminescent device twinkle.
In order to solve the technical problems, one technical scheme adopted by the application is as follows: there is provided a pixel circuit, wherein the pixel circuit includes: the first end of the driving module is connected with a first voltage source; the second end of the adjustable capacitance module is connected with the control end of the driving module, and the first end of the adjustable capacitance module is connected with the second voltage source so as to adjust the capacitance value of the adjustable capacitance module according to the output voltage of the second voltage source; the first end of the light emitting module is connected with the second end of the driving module, and the second end of the light emitting module is connected with a third voltage source.
The second voltage source has at least two output voltages when the pixel circuit corresponds to at least two refresh frequencies, and the adjustable capacitance module has at least two capacitance values corresponding to the at least two output voltages; wherein the output voltage is positively correlated with the refresh frequency and negatively correlated with the capacitance value.
The second voltage source has a first output voltage when the pixel circuit corresponds to a first refresh frequency, and the adjustable capacitance module has a first capacitance value corresponding to the first output voltage; the second voltage source is provided with a second output voltage when the pixel circuit corresponds to a second refresh frequency, and the adjustable capacitance module is provided with a second capacitance value corresponding to the second output voltage; the first refresh frequency is greater than the second refresh frequency, the first output voltage is greater than the second output voltage, and the first capacitance value is less than the second capacitance value.
The pixel circuit further comprises a compensation module, a first end of the compensation module is connected with the control end of the driving module, a second end of the compensation module is connected with the second end of the driving module, and a third end of the compensation module is connected with the second scanning line and used for controlling communication between the control end of the driving module and the second end of the driving module.
The pixel circuit further comprises a first initialization module and a second initialization module, wherein the first end of the first initialization module is connected with the control end of the driving module, the second end of the first initialization module is connected with the first end of the second initialization module and the reference voltage line, the third end of the first initialization module is connected with the first scanning line, the second end of the second initialization module is connected with the first end of the light emitting module, and the third end of the second initialization module is connected with the first scanning line so as to be used for controlling writing of initial voltage into the second end of the adjustable capacitor module and the first end of the light emitting module.
The pixel circuit further comprises a data writing module, a first end of the data writing module is connected with the data line, a second end of the data writing module is connected with the first end of the driving module, and a third end of the data writing module is connected with the second scanning line so as to be used for providing data voltage on the data line to the first end of the driving module.
The pixel circuit further comprises a first light-emitting control module and a second light-emitting control module, wherein a first end of the first light-emitting control module is connected with a first voltage source, a second end of the first light-emitting control module is connected with a first end of the driving module, and a third end of the first light-emitting control module is connected with an emission signal line for controlling communication between the first voltage source and the first end of the driving module; the first end of the second light-emitting control module is connected with the second end of the driving module, the second end of the second light-emitting control module is connected with the first end of the light-emitting module, and the third end of the second light-emitting control module is connected with the emission signal line so as to be used for controlling the communication between the second end of the driving module and the first end of the light-emitting module.
The adjustable capacitance module comprises a variable capacitance with a MOS capacitance structure.
In order to solve the technical problem, another technical scheme adopted by the application is as follows: there is provided a driving method of a pixel circuit, applied to the pixel circuit as described above, wherein the driving method includes: in the data writing and threshold compensation stage, the data writing module is controlled to be conducted so as to transmit the data voltage to the first end of the adjustable capacitance module, and the adjustable capacitance module is used for coupling and writing the data voltage to the control end of the driving module; and controlling the conduction of the compensation module, and charging the control end of the driving module to compensate the threshold voltage of the driving module; and in the light-emitting stage in the display period, the first light-emitting control module and the second light-emitting control module are controlled to be conducted so that the driving module drives the light-emitting module to emit light according to the voltages of the control end and the second end of the driving module.
In order to solve the technical problem, another technical scheme adopted by the application is as follows: providing a display panel, wherein the display panel comprises a driving circuit and a pixel circuit which are connected; wherein the pixel circuit is any one of the above.
The beneficial effects of this application are: compared with the prior art, the pixel circuit has the advantages that the first end of the driving module in the pixel circuit is connected with the first voltage source, the second end of the adjustable capacitor module is connected with the control end of the driving module, the first end of the adjustable capacitor module is connected with the second voltage source, the capacitance value of the adjustable capacitor module is adjusted according to the output voltage of the second voltage source, the first end of the light emitting module is connected with the second end of the driving module, the second end of the light emitting module is connected with the third voltage source, so that the pixel circuit can use the output voltage of the second voltage source required by low capacitance value during high-frequency display, namely, the output voltage of the second voltage source is adjusted, the capacitance value of the adjustable capacitor module is reduced, the charging time of the adjustable capacitor module is shortened, and the compensation effect is ensured; and when the display is performed at low frequency, the output voltage of the second voltage source required by the high capacitance value is used to increase the capacitance value of the adjustable capacitance module, so that the stable voltage of the light-emitting module can be ensured not to flicker.
Drawings
For a clearer description of the technical solutions in the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:
fig. 1 is a schematic structural diagram of a first embodiment of a pixel circuit of the present application;
fig. 2 is a schematic structural diagram of a second embodiment of a pixel circuit of the present application;
FIG. 3 is a schematic diagram of an embodiment of the pixel circuit of FIG. 2;
FIG. 4 is a timing diagram of control signals corresponding to the driving method of the pixel circuit in FIG. 3;
FIG. 5 is a schematic diagram showing the capacitance of the adjustable capacitance module in the pixel circuit of FIG. 3 as a function of voltage;
FIG. 6 is a schematic diagram of the gray scale development simulation result of the pixel circuit of FIG. 3;
FIG. 7 is a flow chart of an embodiment of a driving method of a pixel circuit of the present application;
fig. 8 is a schematic structural diagram of an embodiment of a display panel of the present application.
Detailed Description
The following description of the technical solutions in the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
The terms "first," "second," "third," and the like in this application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", and "a third" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise. All directional indications (such as up, down, left, right, front, back … …) in the embodiments of the present application are merely used to explain the relative positional relationship, movement, etc. between the components in a particular gesture (as shown in the drawings), and if the particular gesture changes, the directional indication changes accordingly. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.
The present application is described in detail below with reference to the accompanying drawings and examples.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a first embodiment of a pixel circuit of the present application. In the present embodiment, the pixel circuit 10 includes: a driving module 11, an adjustable capacitance module 12 and a light emitting module 13.
It should be noted that, in the display technical field, the display panel generally continuously provides a current to the light emitting module 13 in the pixel circuit 10 through a constant current source correspondingly output by the system power supply to the pixel circuit 10, wherein the magnitude of the current is specifically controlled by the voltage adjustment of the control terminal of the driving module 11 in the pixel circuit 10, and the voltage of the control terminal of the driving module 11 is written by the data signal correspondingly provided by the driving circuit of the display panel to the pixel circuit 10 so as to be stored in the adjustable capacitor module 12 in the pixel circuit 10, so that the light emitting module 13 can continuously emit light in a scanning period of the driving circuit to realize corresponding image display.
Specifically, the first end of the driving module 11 is correspondingly connected to the first voltage source 101 provided by the system power supply, and the first voltage source 101 is specifically a constant current source.
The second end of the adjustable capacitor module 12 is specifically connected to the control end of the driving module 11, and the first end of the adjustable capacitor module 12 is connected to the system power supply or the second voltage source 102 correspondingly provided by the driving circuit.
The output voltage of the second voltage source 102 is adjustable, and specifically, the system power supply, or the driving circuit is correspondingly adjusted according to the current refresh frequency of the display panel, so that the capacitance value of the adjustable capacitance module 12 can be further adjusted according to the output voltage of the second voltage source 102, for example, when the display panel displays at high frequency, the capacitance value of the adjustable capacitance module 12 is reduced by increasing the output voltage of the second voltage source 102; and when the display panel displays at a low frequency, the capacitance value of the adjustable capacitance module 12 is increased by reducing the output voltage of the second voltage source 102.
Further, the first end of the light emitting module 13 is specifically connected to the second end of the driving module 11, and the second end of the light emitting module 13 is correspondingly connected to the third voltage source 103 provided by the system power supply, so as to continuously emit light based on the output voltages correspondingly provided by the driving module 11 and the third voltage source 103 in a scanning period of the driving circuit, so as to realize corresponding image display.
It should be noted that, for the display panel, the more the number of times of refreshing the display image on the display panel, the smaller the flicker of the image display, and the higher the picture quality. That is, the higher the refresh frequency of the display panel, the better the image quality display, but the more the power consumption is simultaneously. Therefore, when high quality image quality is not required, the refresh frequency of the display panel is usually low, and when high quality image quality is required, the refresh frequency of the display panel is high, so that the balance between image quality and energy consumption is achieved.
Wherein, when the display panel works at high frequency (refresh frequency is relatively high), the charging time of the adjustable capacitance module 12 is shortened, and the holding time required by the voltage of the control terminal of the driving module 11 is also shortened; when the display panel is operated at a low frequency (refresh frequency is relatively low), the charging time of the adjustable capacitance module 12 is long, and the charging time required for the voltage of the control terminal of the driving module 11 is also long.
Therefore, the different refresh frequencies in the display panel have different requirements for the stability of the voltage of the control end of the driving module 11, so that the control end of the driving module 11 is connected with an adjustable capacitance module 12, and the capacitance value of the adjustable capacitance module 12 is related to the refresh frequency of the display panel, so that when the refresh frequency of the display panel changes, the capacitance value of the adjustable capacitance module 12 can also change, so as to maintain the stability of the voltage of the control end of the driving module 11, so as to meet the requirements of the current refresh frequency, thereby being capable of performing variable-frequency display and meeting different display requirements.
It can be understood that, to meet the above requirement, that is, to shorten the charging time of the adjustable capacitance module 12 during high-frequency display, ensure the compensation effect, and to ensure that the light emitting module 13 does not flicker during low-frequency display, the output voltage of the second voltage source 102 is specifically positively related to the refresh frequency of the display panel, and is negatively related to the capacitance value of the adjustable capacitance module 12, that is, when the refresh frequency is higher, the output voltage of the second voltage source 102 is also higher, and the capacitance value of the adjustable capacitance module 12 is smaller.
In the above scheme, during high-frequency display, the pixel circuit 10 uses the output voltage of the second voltage source 102 required by the low capacitance value, that is, adjusts the output voltage of the second voltage source 102, so as to reduce the capacitance value of the adjustable capacitance module 12, so as to shorten the charging time of the adjustable capacitance module 12, thereby effectively ensuring the compensation effect; in low-frequency display, the pixel circuit 10 uses the output voltage of the second voltage source 102 required by high capacitance to increase the capacitance of the adjustable capacitance module 12, so as to effectively ensure that the light emitting module 13 is stable in voltage and does not flicker.
In an embodiment, when the second voltage source 102 corresponds to at least two refresh frequencies in the pixel circuit 10, that is, the corresponding display panel has at least two refresh frequencies, the second voltage source 102 also corresponds to at least two output voltages, and the adjustable capacitance module 12 also has at least two capacitance values corresponding to at least two output voltages.
Wherein the output voltage is positively correlated with the refresh frequency and negatively correlated with the capacitance value, i.e., when the refresh frequency is large, the output voltage is also large and the capacitance value is small; when the refresh frequency is smaller, the output voltage is smaller, and the capacitance value is larger.
Further, in a specific embodiment, when the second voltage source 102 corresponds to the first refresh frequency of the pixel circuit 10, the second voltage source has a first output voltage, and the adjustable capacitance module 12 has a first capacitance value corresponding to the first output voltage; when the second voltage source 102 corresponds to the second refresh frequency of the pixel circuit 10, the second output voltage is correspondingly provided, and the adjustable capacitance module 12 has a second capacitance value corresponding to the second output voltage; the first refresh frequency is specifically greater than the second refresh frequency, the first output voltage is greater than the second output voltage, and the first capacitance value is smaller than the second capacitance value.
Alternatively, the tunable capacitor module 12 may specifically include a variable capacitor having a MOS capacitor structure, that is, a metal layer-insulating layer-semiconductor layer stacked on each other, or any other reasonable capacitor having a structure that can vary according to the voltage of the electrode plate, which is not limited in this application.
Referring to fig. 2, fig. 2 is a schematic structural diagram of a second embodiment of the pixel circuit of the present application. The present embodiment is based on the first embodiment of the pixel circuit provided in the present application, and the pixel circuit 20 specifically further includes a compensation module 24.
Specifically, the first end of the compensation module 24 is correspondingly connected to the control end of the driving module 21, the second end of the compensation module 24 is connected to the second end of the driving module 21, the third end of the compensation module 24 is correspondingly connected to the second scan line 202 in the display panel, so as to receive the second scan signal provided to the third end of the compensation module 24 by the second scan line 202, and when the second scan signal is triggered to be turned on, the control end of the driving module 21 is controlled to be communicated with the second end of the driving module 21, so as to compensate the threshold voltage of the driving module 21, and the serious non-uniformity of the light emission caused by the change of the light emitting brightness of the light emitting module 23 due to the unstable threshold voltage is avoided.
In an embodiment, the pixel circuit 20 specifically further includes a first initialization module 251 and a second initialization module 252, wherein a first end of the first initialization module 251 is connected to the control end of the driving module 21, and a second end of the first initialization module 251 is connected to a first end of the second initialization module 252 and the reference voltage line 204 in the display panel, so that the first initialization module 251 and the second initialization module 252 can receive the reference voltage line 204 to correspondingly provide an initial voltage.
Further, the third end of the first initialization module 251 is connected to the first scan line 201, the second end of the second initialization module 252 is connected to the first end of the light emitting module 23, and the third end of the second initialization module 252 is correspondingly connected to the first scan line 201, and the first initialization module 251 and the second initialization module 252 are configured to receive a first scan signal correspondingly provided by the first scan line 201, so as to write an initial voltage correspondingly provided by the reference voltage line 204 into the second end of the adjustable capacitance module 22 and the first end of the light emitting module 23 when the first scan signal triggers on, so as to initialize the adjustable capacitance module 22 and the light emitting module 23 at the same time, that is, reset the same so as to clear signal residues that may exist in the previous stage.
In an embodiment, the pixel circuit 20 specifically further includes a data writing module 26, and a first end of the data writing module 26 is connected to a data line 203 in the display panel for receiving a data signal correspondingly provided by the data line 203.
The second end of the data writing module 26 is correspondingly connected to the first end of the driving module 21, and the third end of the data writing module 26 is connected to the second scan line 202, so as to receive a second scan signal correspondingly provided by the second scan line 202, and when the second scan signal triggers on, the data voltage on the data line 203 is provided to the first end of the driving module 21 to be stored in the adjustable capacitor module 22, and when the driving module 21 triggers on, the data voltage is correspondingly output to the light emitting module 23, the light emitting module 23 is ensured to continuously emit light in a scan period, so as to realize corresponding image display.
In an embodiment, the pixel circuit 20 specifically further includes a first light emitting control module 271 and a second light emitting control module 272, where a first end of the first light emitting control module 271 is connected to the first voltage source 101 correspondingly provided by the system power supply, a second end of the first light emitting control module 271 is connected to the first end of the driving module 21, and a third end of the first light emitting control module 271 is connected to the emission signal line 205 in the display panel, so as to receive an emission signal correspondingly provided by the emission signal line 205, and trigger conduction under the action of the emission signal, so as to control the first voltage source 101 to communicate with the first end of the driving module 21.
The first end of the second light emitting control module 272 is connected to the second end of the driving module 21, the second end of the second light emitting control module 272 is connected to the first end of the light emitting module 23, and the third end of the second light emitting control module 272 is correspondingly connected to the emission signal line 205, so as to receive the emission signal correspondingly provided by the emission signal line 205, and trigger conduction under the action of the emission signal, so as to control the second end of the driving module 21 to be communicated with the first end of the light emitting module 23, and further correspondingly output the data voltage stored in the adjustable capacitance module 22 to the light emitting module 23, so as to ensure that the light emitting module 23 continuously emits light in a scanning period.
Optionally, the driving module 21, the compensation module 24, the first initialization module 251, the second initialization module 252, the data writing module 26, the first light emitting control module 271 and the second light emitting control module 272 may include any reasonable switching device such as a transistor, a P-type thin film transistor, an N-type thin film transistor and a field effect transistor, which is not limited in this application.
It should be noted that, to distinguish the two ends of the driving module 21 except the control end, one of the two ends is called a first end, and the other is called a second end. When the driving module 21 is a triode, the control end can be specifically a base electrode, the first end is a collector electrode, and the second end is an emitter electrode; alternatively, the control terminal may be a base, and the first terminal may be an emitter, and the second terminal may be a collector.
When the driving module 21 is a thin film transistor or a field effect transistor, the control terminal may be a gate, the first terminal is a drain, and the second terminal is a source; alternatively, the control terminal may be a gate electrode, and the first terminal may be a source electrode, and the second terminal may be a drain electrode.
And the first end, the second end and the third end of each module except the driving module 21 respectively correspond to the first end, the second end and the control end of the driving module 21.
When each module is a thin film transistor or a field effect transistor, a composite transistor or a single transistor may be specifically used, which is not limited in this application.
For convenience of understanding, taking the above modules as examples, the above modules are specifically P-type thin film transistors, please refer to fig. 3 and fig. 4 in combination, wherein fig. 3 is a schematic structural diagram of an embodiment of the pixel circuit in fig. 2, and fig. 4 is a schematic timing diagram of a control signal corresponding to the driving method of the pixel circuit in fig. 3.
It is understood that, in the present embodiment, as shown in fig. 3, the driving module 21, the compensation module 24, the first initialization module 251, the second initialization module 252, the data writing module 26, the first light emitting control module 271 and the second light emitting control module 272 may specifically correspond to a first transistor T1, a third transistor T3, a fourth transistor T4, a seventh transistor T7, a second transistor T2, a fifth transistor T5 and a sixth transistor T6, respectively; the adjustable capacitance module 22 is correspondingly a variable capacitance Cst, and the light emitting module 23 is correspondingly a light emitting device LED; the first Scan line 201, the second Scan line 202, the data line 203, the reference voltage line 204 and the emission signal line 205 correspond to the first Scan line Scan1, the second Scan line Scan2, the data line Vdata, the reference voltage line Vref and the emission signal line EM, respectively; the first voltage source 101, the second voltage source 102 and the third voltage source 103 are respectively corresponding to the first voltage source Vdd, the second voltage source Vhd and the third voltage source Vss; the third transistor T3 and the fourth transistor T4 may be specifically composite transistors, so as to reduce the requirement of the device on the driving power, and the connection manner of the corresponding elements is specifically shown in fig. 3, which is not described herein again.
As shown in fig. 4, in the initialization stage, that is, in the T1 stage, the first Scan signal correspondingly provided by the first Scan line Scan1 has a low level state, so that the fourth transistor T4 and the seventh transistor T7 can be correspondingly controlled to trigger and turn on, and thus the initial voltages correspondingly provided by the emission signal line EM are respectively written into the variable capacitor Cst and the light emitting device LED, so as to initialize the variable capacitor Cst and the light emitting device LED at the same time, that is, the variable capacitor Cst and the light emitting device LED are reset, so as to clear signal residues that may exist in the previous stage.
Further, in the data writing and threshold compensation stage, that is, in the T2 stage, the second Scan signal corresponding to the second Scan line Scan2 has a low level state, so as to correspondingly control the second transistor T2 and the third transistor T3 to trigger and turn on, so as to transmit the data voltage corresponding to the data line Vdata to the first end of the variable capacitor Cst, and make the variable capacitor Cst couple the writing data voltage to the control end of the first transistor T1; and at the same time, the third transistor T3 will charge the control terminal of the first transistor T1 to compensate the threshold voltage of the first transistor T1.
Still further, in a light emitting stage in the display period, that is, in a stage T3, the emission signal line EM has a low level state corresponding to the provided emission signal, so as to correspondingly control the fifth transistor T5 and the sixth transistor T6 to trigger and turn on, so that the first transistor T1 drives the light emitting device LED to emit light according to the voltages of the control terminal and the second terminal thereof.
It can be understood that, as shown in fig. 5, fig. 5 is a schematic diagram of the capacitance value of the adjustable capacitance module in the pixel circuit of fig. 3 as a function of voltage; the variable capacitor Cst may be specifically configured as a MOS capacitor structure, so that the capacitance value of the variable capacitor Cst can be controlled by the output voltage of the second voltage source Vhd, so that the output voltage of the second voltage source Vhd with a low capacitance value is used during high-frequency display, so as to shorten the charging time and ensure the compensation effect; and the output voltage of the second voltage source Vhd with high capacitance is used during low frequency display to ensure that the voltage regulator does not flicker.
Further, referring to fig. 6, fig. 6 is a schematic diagram of a gray scale development simulation result of the pixel circuit in fig. 3.
Therefore, according to the simulation result, the solution provided by the embodiment can work normally at 3 different display frequencies of high, medium and low, the gray scale is unfolded normally, the current ratio is larger than 1E6 in Vdata range (the difference value between the source and drain currents Ids of the first transistor T1 corresponding to two brightness levels and the gate voltage Vgs thereof) of 0-7V, and the requirement of the switching ratio of the LED of the light emitting device is met.
The application also provides a driving method of the pixel circuit, please refer to fig. 7, fig. 7 is a flow chart of an embodiment of the driving method of the pixel circuit. Specifically, the method may include the steps of:
s31: in the data writing and threshold compensation stage, the data writing module is controlled to be conducted so as to transmit the data voltage to the first end of the adjustable capacitance module, the adjustable capacitance module is coupled with the data voltage to be written into the control end of the driving module, and the compensation module is controlled to be conducted so as to charge the control end of the driving module to compensate the threshold voltage of the driving module.
It can be understood that the driving method in this embodiment is a method for driving the pixel circuit shown in fig. 2 by the driving circuit in the corresponding display panel, and is specifically please refer to fig. 2 and fig. 4 and related text content, which are not repeated here.
In the data writing and threshold compensation stage, i.e. in the t2 stage, the second scan line has a low level state corresponding to the second scan signal provided by the second scan line, so as to correspondingly control the data writing module and the compensation module to trigger and conduct, so as to transmit the data voltage provided by the data line corresponding to the first end of the adjustable capacitor module, and enable the adjustable capacitor module to couple and write the data voltage to the control end of the driving module; and at the same time, the compensation module charges the control end of the driving module to compensate the threshold voltage of the driving module.
S32: and in the light-emitting stage in the display period, the first light-emitting control module and the second light-emitting control module are controlled to be conducted so that the driving module drives the light-emitting module to emit light according to the voltages of the control end and the second end of the driving module.
Further, in a light emitting stage in the display period, that is, in a t3 stage, the emission signal line has a low level state corresponding to the provided emission signal, so that the first light emitting control module and the second light emitting control module can be correspondingly controlled to trigger and conduct, and the driving module drives the light emitting module to emit light according to the voltages of the control end and the second end of the driving module.
Further, in an embodiment, before S31, the method specifically may further include: in the initialization stage, i.e. in the t1 stage, the first scanning signal provided by the first scanning line corresponds to a low level state, so that the first initialization module and the second initialization module can be correspondingly controlled to trigger and conduct, and thus initial voltages provided by the transmitting signal line correspond to the adjustable capacitance module and the light-emitting module are respectively written into the adjustable capacitance module and the light-emitting module, so that the adjustable capacitance module and the light-emitting module are initialized at the same time, i.e. the adjustable capacitance module and the light-emitting module are reset, so that signal residues possibly existing in the previous stage are removed.
The present application also provides a display panel, please refer to fig. 8, fig. 8 is a schematic structural diagram of an embodiment of the display panel of the present application. In the present embodiment, the display panel 40 includes a driving circuit 41 and a pixel circuit 42 connected.
It should be noted that the pixel circuit 42 described in this embodiment is the pixel circuit 10 or the pixel circuit 20 described in any of the above embodiments, and detailed descriptions thereof will be omitted herein with reference to fig. 1-6 and related text.
The beneficial effects of this application are: compared with the prior art, the pixel circuit has the advantages that the first end of the driving module in the pixel circuit is connected with the first voltage source, the second end of the adjustable capacitor module is connected with the control end of the driving module, the first end of the adjustable capacitor module is connected with the second voltage source, the capacitance value of the adjustable capacitor module is adjusted according to the output voltage of the second voltage source, the first end of the light emitting module is connected with the second end of the driving module, the second end of the light emitting module is connected with the third voltage source, so that the pixel circuit can use the output voltage of the second voltage source required by low capacitance value during high-frequency display, namely, the output voltage of the second voltage source is adjusted, the capacitance value of the adjustable capacitor module is reduced, the charging time of the adjustable capacitor module is shortened, and the compensation effect is ensured; and when the display is performed at low frequency, the output voltage of the second voltage source required by the high capacitance value is used to increase the capacitance value of the adjustable capacitance module, so that the stable voltage of the light-emitting module can be ensured not to flicker.
The foregoing description is only of embodiments of the present application, and is not intended to limit the scope of the patent application, and all equivalent structures or equivalent processes using the descriptions and the contents of the present application or other related technical fields are included in the scope of the patent application.

Claims (10)

1. A pixel circuit, the pixel circuit comprising:
the first end of the driving module is connected with a first voltage source;
the second end of the adjustable capacitance module is connected with the control end of the driving module, and the first end of the adjustable capacitance module is connected with a second voltage source so as to adjust the capacitance value of the adjustable capacitance module according to the output voltage of the second voltage source;
the first end of the light emitting module is connected with the second end of the driving module, and the second end of the light emitting module is connected with a third voltage source.
2. The pixel circuit according to claim 1, wherein,
the second voltage source is provided with at least two output voltages when the pixel circuit corresponds to at least two refresh frequencies, and the adjustable capacitance module is provided with at least two capacitance values corresponding to at least two output voltages; wherein the output voltage is positively correlated with the refresh frequency and negatively correlated with the capacitance value.
3. The pixel circuit according to claim 2, wherein,
the second voltage source has a first output voltage when the pixel circuit corresponds to a first refresh frequency, and the adjustable capacitance module has a first capacitance value corresponding to the first output voltage;
the second voltage source has a second output voltage when the pixel circuit corresponds to a second refresh frequency, and the adjustable capacitance module has a second capacitance value corresponding to the second output voltage;
the first refresh frequency is greater than the second refresh frequency, the first output voltage is greater than the second output voltage, and the first capacitance value is less than the second capacitance value.
4. The pixel circuit according to claim 1, wherein,
the pixel circuit further comprises a compensation module, a first end of the compensation module is connected with the control end of the driving module, a second end of the compensation module is connected with the second end of the driving module, and a third end of the compensation module is connected with a second scanning line and used for controlling communication between the control end of the driving module and the second end of the driving module.
5. The pixel circuit of claim 4, wherein,
the pixel circuit further comprises a first initialization module and a second initialization module, wherein a first end of the first initialization module is connected with a control end of the driving module, a second end of the first initialization module is connected with a first end of the second initialization module and a reference voltage line, a third end of the first initialization module is connected with a first scanning line, a second end of the second initialization module is connected with a first end of the light emitting module, and a third end of the second initialization module is connected with the first scanning line so as to be used for controlling writing of initial voltage into a second end of the adjustable capacitor module and the first end of the light emitting module.
6. The pixel circuit of claim 5, wherein,
the pixel circuit further comprises a data writing module, wherein a first end of the data writing module is connected with the data line, a second end of the data writing module is connected with the first end of the driving module, and a third end of the data writing module is connected with the second scanning line so as to be used for providing data voltage on the data line to the first end of the driving module.
7. The pixel circuit of claim 6, wherein,
the pixel circuit further comprises a first light-emitting control module and a second light-emitting control module, wherein a first end of the first light-emitting control module is connected with the first voltage source, a second end of the first light-emitting control module is connected with a first end of the driving module, and a third end of the first light-emitting control module is connected with an emission signal line for controlling communication between the first voltage source and the first end of the driving module;
the first end of the second light-emitting control module is connected with the second end of the driving module, the second end of the second light-emitting control module is connected with the first end of the light-emitting module, and the third end of the second light-emitting control module is connected with the emission signal line so as to be used for controlling the communication between the second end of the driving module and the first end of the light-emitting module.
8. The pixel circuit according to any one of claims 1 to 7, wherein,
the tunable capacitance module includes a variable capacitance having a MOS capacitance structure.
9. A driving method of a pixel circuit, characterized by being applied to the pixel circuit described in claim 7, comprising:
in the data writing and threshold compensation stage, controlling the data writing module to be conducted so as to transmit the data voltage to the first end of the adjustable capacitance module, wherein the adjustable capacitance module is used for writing the data voltage into the control end of the driving module in a coupling way; and controlling the compensation module to be conducted, and charging a control end of the driving module to compensate the threshold voltage of the driving module;
and in a light-emitting stage in the display period, controlling the first light-emitting control module and the second light-emitting control module to be conducted so that the driving module drives the light-emitting module to emit light according to the voltages of the control end and the second end of the driving module.
10. A display panel, characterized in that the display panel comprises a driving circuit and a pixel circuit which are connected;
wherein the pixel circuit is a pixel circuit according to any one of claims 1 to 8.
CN202310245862.XA 2023-03-09 2023-03-09 Pixel circuit, driving method thereof and display panel Pending CN116486760A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310245862.XA CN116486760A (en) 2023-03-09 2023-03-09 Pixel circuit, driving method thereof and display panel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310245862.XA CN116486760A (en) 2023-03-09 2023-03-09 Pixel circuit, driving method thereof and display panel

Publications (1)

Publication Number Publication Date
CN116486760A true CN116486760A (en) 2023-07-25

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310245862.XA Pending CN116486760A (en) 2023-03-09 2023-03-09 Pixel circuit, driving method thereof and display panel

Country Status (1)

Country Link
CN (1) CN116486760A (en)

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