CN112908245A - 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
CN112908245A
CN112908245A CN202110209332.0A CN202110209332A CN112908245A CN 112908245 A CN112908245 A CN 112908245A CN 202110209332 A CN202110209332 A CN 202110209332A CN 112908245 A CN112908245 A CN 112908245A
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transistor
initialization
control signal
pole
driving
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CN112908245B (en
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胡思明
徐思维
齐栋宇
朱杰
张露
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Kunshan Govisionox Optoelectronics Co Ltd
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Kunshan Govisionox Optoelectronics Co Ltd
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • 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]

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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)
  • Control Of El Displays (AREA)

Abstract

The invention discloses a pixel circuit, a driving method thereof and a display panel. The pixel circuit includes: a driving transistor for generating a driving current in response to a data signal; a light emitting device connected in series with the driving transistor for emitting light in response to the driving current; the first initialization module comprises a first transistor, wherein a first pole of the first transistor is connected with a first initialization control signal, a second pole of the first transistor is electrically connected with an anode of the light-emitting device, and a grid electrode of the first transistor is electrically connected with the first pole or the second pole of the first transistor; the first initialization control signal is used to initialize the anode of the light emitting device. Compared with the prior art, the embodiment of the invention improves the contrast ratio of the display panel and the display effect.

Description

Pixel circuit, driving method thereof and display panel
Technical Field
The embodiment of the invention relates to the technical field of display, in particular to a pixel circuit, a driving method thereof and a display panel.
Background
With the continuous development of display technology, the application range of display panels is wider and wider, and the requirements of people on the display panels are higher and higher. In particular, the display quality of the display panel is always one of the important indicators for the quality of the display panel for consumers and panel manufacturers. In a conventional display panel, a plurality of pixel circuits and light emitting devices are generally included, and the light emitting devices are driven by the pixel circuits to emit light, thereby performing display. However, the display of the conventional display panel has a phenomenon of low contrast, which affects the display effect of the display panel.
Disclosure of Invention
The embodiment of the invention provides a pixel circuit, a driving method thereof and a display panel, which are used for improving the contrast of the display panel and improving the display effect.
In order to achieve the technical purpose, the embodiment of the invention provides the following technical scheme:
a pixel circuit, comprising:
a driving transistor for generating a driving current in response to a data signal;
a light emitting device connected in series with the driving transistor for emitting light in response to the driving current;
the first initialization module comprises a first transistor, wherein a first pole of the first transistor is connected to a first initialization control signal, a second pole of the first transistor is electrically connected with the anode of the light-emitting device, and a grid electrode of the first transistor is electrically connected with the first pole or the second pole of the first transistor; the first initialization control signal is used to initialize the anode of the light emitting device.
It can be seen from the foregoing technical solutions that the embodiment of the present invention provides a pixel circuit structure, where the pixel circuit includes a first initialization module, which can initialize an anode of a light emitting device, complete resetting of the anode of the light emitting device, and avoid an influence of previous frame light emission on a current frame. The first initialization module comprises a first transistor, the first transistor is connected in a diode connection mode, and the first initialization control signal directly initializes the light-emitting device. Compared with the general situation that the first electrode of the first transistor is connected with the reference signal, in order to ensure the conduction of the first transistor, the connection mode can ensure that the first initialization control signal is lower than the reference signal or lower than the voltage of the cathode of the light-emitting device, so that the contrast ratio is improved.
Further, the first transistor is a P-type transistor, and a gate of the first transistor is electrically connected to a first pole of the first transistor;
or, the first transistor is an N-type transistor, and a gate of the first transistor is electrically connected to the second pole of the first transistor.
Further, a first pole of the driving transistor is used for connecting a first power supply signal, and a second pole of the driving transistor is used for being electrically connected with the light-emitting device;
the pixel circuit further includes:
the second initialization module comprises a control end, a first end and a second end; a control end of the second initialization module is connected with a second initialization control signal, a first end of the second initialization module is connected with a first initialization voltage signal, and a second end of the second initialization module is electrically connected with a grid electrode of the driving transistor; the second initialization module is used for initializing the grid electrode of the driving transistor;
the third initialization module comprises a control end, a first end and a second end; a control end of the third initialization module is connected to a third initialization control signal, a first end of the third initialization module is connected to a second initialization voltage signal, and a second end of the third initialization module is electrically connected to the first pole of the driving transistor; the third initialization module is used for initializing the first pole of the driving transistor.
The embodiment of the invention realizes the initialization of the grid electrode of the driving transistor by arranging the second initialization module; the initialization of the first pole of the driving transistor is realized by arranging a third initialization module; thereby reducing the hysteresis voltage of the drive transistor. That is, the gate and the source of the driving transistor are both forced to reset, so as to fully avoid the influence of the display of the previous frame on the current frame and improve the afterimage.
Further, the second initialization module includes: a second transistor; a grid electrode of the second transistor is connected with a second initialization control signal, a first pole of the second transistor is connected with a first initialization voltage signal, and a second pole of the second transistor is electrically connected with a grid electrode of the driving transistor;
the third initialization module includes: a third transistor; the grid electrode of the third transistor is connected with a third initialization control signal, the first pole of the third transistor is connected with a second initialization voltage signal, and the second pole of the third transistor is electrically connected with the first pole of the driving transistor.
Further, a gate of the third transistor is electrically connected to the first pole or the second pole of the third transistor, and the third initialization control signal is multiplexed into the second initialization voltage signal. In this way, the third transistor is set to be in a diode connection mode, and the third initialization control signal is multiplexed with the second initialization voltage signal, so that the number of signal lines can be reduced, which is favorable for wiring of the display panel.
Preferably, the third transistor is a P-type transistor, and a gate of the third transistor is electrically connected to a first pole of the third transistor.
Further, the first initialization control signal is multiplexed into the second initialization control signal; and/or the first initialization control signal is multiplexed into the third initialization control signal. By the arrangement, the number of control signal lines can be further reduced, and the wiring of the display panel is facilitated; meanwhile, the design of the driving circuit can be simplified by reducing the number of the control signal lines, and the narrow frame design of the display panel is facilitated.
Further, still include: a light emission control module; the light emitting control module comprises a fourth transistor and a fifth transistor;
a grid electrode of the fourth transistor is connected with a light-emitting control signal, and the fourth transistor is connected between a first power supply signal and the first pole of the driving transistor in series;
the grid electrode of the fifth transistor is connected with the light-emitting control signal, and the fifth transistor is connected between the second pole of the driving transistor and the anode of the light-emitting device in series.
Preferably, the pixel circuit further includes: a storage module; the storage module comprises a first end and a second end, and the first end of the storage module is connected to the first power supply signal; the second end of the storage module is electrically connected with the grid electrode of the driving transistor;
preferably, the storage module includes: a capacitor; the first end of the capacitor is connected with the first power supply signal, and the second end of the capacitor is electrically connected with the grid electrode of the driving transistor. Further, still include: a data writing module; the data writing module comprises a sixth transistor and a seventh transistor;
a gate of the sixth transistor is connected to a data writing control signal, a first pole of the sixth transistor is connected to a data signal, and a second pole of the sixth transistor is electrically connected to the first pole of the driving transistor;
the gate of the seventh transistor is connected to the data write control signal, the first pole of the seventh transistor is electrically connected to the gate of the driving transistor, and the second pole of the seventh transistor is electrically connected to the second pole of the driving transistor.
Preferably, the pixel circuit further includes: a cathode initialization module; the cathode initialization module comprises a first end, a second end, a third end and a fourth end; a first end of the cathode initialization module is connected with a fourth initialization control signal, a second end of the cathode initialization module is electrically connected with a cathode of the light-emitting device, a third end of the cathode initialization module is connected with a light-emitting control signal, and a fourth end of the cathode initialization module is connected with a second power supply signal;
preferably, the cathode initialization module includes: an eighth transistor and a ninth transistor; a first pole of the eighth transistor is connected to a fourth initialization control signal; a second pole of the eighth transistor is electrically connected with a second pole of the ninth transistor and serves as a second end of the cathode initialization module; a gate of the eighth transistor is electrically connected to the first or second pole of the eighth transistor; the grid electrode of the ninth transistor is connected with the light-emitting control signal; the first pole of the ninth transistor is connected to the second power supply signal. Accordingly, the present invention also provides a display panel comprising: any embodiment of the invention provides a pixel circuit.
Correspondingly, the invention also provides a driving method of the pixel circuit, which comprises the following steps:
the first initialization control signal controls the first initialization module to be conducted so that the first initialization control signal initializes the light emitting device.
The embodiment of the invention provides a pixel circuit structure, which comprises a first initialization module, can realize the initialization of an anode of a light-emitting device, complete the reset of the light-emitting device and avoid the influence of the light emission of the previous frame on the current frame. The first initialization module comprises a first transistor, the grid electrode of the first transistor is electrically connected with the first pole or the second pole of the first transistor to form a diode connection mode, and the first initialization control signal can directly initialize the anode of the light-emitting device, so that the number of signal lines in the pixel circuit is reduced. In addition, compared with the scheme that a reference signal is connected to the first pole of the first transistor and the reference voltage is adopted to initialize the anode of the light-emitting device in the prior art, the embodiment of the invention can initialize the anode of the light-emitting device at lower voltage, thereby effectively reducing the light-emitting brightness of the light-emitting device at low gray scale, being beneficial to improving the contrast of the display panel and improving the display effect.
Drawings
Fig. 1 is a circuit diagram of a pixel circuit according to an embodiment of the invention;
fig. 2 is a schematic diagram of a driving timing sequence of a pixel circuit according to an embodiment of the invention;
FIG. 3 is a circuit diagram of another pixel circuit according to an embodiment of the present invention;
fig. 4 is a circuit diagram of another pixel circuit according to an embodiment of the invention;
fig. 5 is a circuit diagram of another pixel circuit according to an embodiment of the invention;
fig. 6 is a circuit diagram of another pixel circuit according to an embodiment of the invention;
FIG. 7 is a schematic diagram illustrating a driving timing sequence of a pixel circuit according to another embodiment of the present invention;
fig. 8 is a circuit diagram of another pixel circuit according to an embodiment of the invention;
FIG. 9 is a schematic diagram illustrating a driving timing sequence of a pixel circuit according to another embodiment of the present invention;
fig. 10 is a circuit diagram of another pixel circuit according to an embodiment of the invention;
FIG. 11 is a schematic diagram illustrating a driving timing sequence of a pixel circuit according to another embodiment of the present invention;
fig. 12 is a circuit diagram of another pixel circuit according to an embodiment of the invention;
FIG. 13 is a schematic diagram illustrating a driving timing sequence of a pixel circuit according to another embodiment of the present invention;
fig. 14 is a circuit diagram of another pixel circuit according to an embodiment of the invention;
FIG. 15 is a schematic diagram illustrating a driving timing sequence of a pixel circuit according to another embodiment of the present invention;
fig. 16 is a circuit diagram of another pixel circuit according to an embodiment of the invention;
FIG. 17 is a schematic diagram illustrating a driving timing sequence of a pixel circuit according to another embodiment of the present invention;
fig. 18 is a circuit diagram of another pixel circuit according to an embodiment of the invention;
fig. 19 is a schematic structural diagram of a display panel according to an embodiment of the present invention;
fig. 20 is a flowchart illustrating a driving method of a pixel circuit according to an embodiment of the invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
The embodiment of the invention provides a pixel circuit which can be applied to display panels such as an organic light-emitting diode display panel, a micro light-emitting diode display panel or a quantum dot light-emitting diode display panel. Fig. 1 is a circuit diagram of a pixel circuit according to an embodiment of the present invention. Referring to fig. 1, the pixel circuit includes: a driving transistor DTFT, a light emitting device OLED, and a first initialization module 110.
Wherein the driving transistor DTFT is for generating a driving current in response to the data signal Vdata; the light emitting device OLED is connected in series with the driving transistor DTFT for emitting light in response to the driving current; the first initialization module 110 includes a first transistor M1, a first pole of the first transistor M1 is connected to the first initialization control signal S1, a second pole of the first transistor M1 is electrically connected to the anode of the light emitting device OLED, and a gate of the first transistor M1 is electrically connected to the first pole or the second pole thereof; the first initialization control signal S1 is used to initialize the anode of the light emitting device OLED.
The pixel circuit provided by the embodiment of the invention initializes the anode of the light emitting device OLED through the first initialization module 110, completes the reset of the light emitting device OLED, and avoids the influence of the previous frame light emission on the current frame. The first initialization module 110 includes a first transistor M1, a gate of the first transistor M1 is electrically connected to a first pole or a second pole of the first transistor M1 to form a diode connection, and the first initialization control signal S1 can directly initialize an anode of the light emitting device OLED.
However, in the prior art, the first transistor M1 is a P-type transistor, and the anode of the light emitting device OLED is initialized, for example, the gate of the first transistor M1 is connected to the control signal, the first electrode is connected to the reference signal, the gate control signal (denoted as VGL, which may be-7V, -10V, or-14V, for example) and the reference voltage signal (denoted as Vref, which may be-5V, -8V, or-12V, for example) are separated. In order to ensure that the first transistor M1 is turned on, the voltage of the gate control signal VGL needs to be set lower than the voltage of the reference voltage signal Vref, i.e., VGL < Vref. That is, the voltage of the reference voltage signal Vref initializing the anode of the light emitting device OLED cannot be set too low. The embodiment of the invention changes the connection mode of the existing first transistor M1, so that the first initialization control signal S1 (the gate control signal VGL) is used as a reference voltage signal to initialize the anode of the light-emitting device OLED, and the voltage written into the anode of the light-emitting device OLED is lower because VGL is less than Vref. Therefore, compared with the prior art, the embodiment of the invention can provide lower initialization voltage for the anode of the light emitting device OLED, and achieve better initialization effect.
For the pixel circuit which completes the initialization of the light emitting device OLED, because the driving current generated by the driving transistor DTFT is smaller and the light emitting device OLED is charged more slowly when the low gray scale (such as black state) display is performed, the charging time of the light emitting device OLED in one frame is increased, the actual light emitting time is reduced, so that the average brightness is reduced, and the lower initialization voltage is favorable for reducing the low gray scale light emitting brightness of the light emitting device OLED; and when the high gray scale is displayed, the driving current generated by the driving transistor DTFT is larger, the charging of the light-emitting device OLED is faster, and the lower initialization voltage has no obvious influence on the light-emitting device OLED. In summary, the embodiment of the invention not only reduces the number of signal lines of the pixel circuit, but also reduces the initialization voltage of the anode of the light emitting device OLED, thereby increasing the brightness difference of the light emitting device OLED in low gray scale and high gray scale display and increasing the contrast of the display panel.
In the above-described embodiments, the first pole of the driving transistor DTFT may be referred to as a source electrode, and the second pole of the driving transistor DTFT may be referred to as a drain electrode, and since the structures of the transistors are symmetrical in the display panel, the source electrode and the drain electrode of the transistors such as the driving transistor DTFT are not distinguished.
With continued reference to fig. 1, optionally, a first pole of the driving transistor DTFT is used to switch in the first power signal VDD, and a second pole of the driving transistor DTFT is used to electrically connect with the light emitting device OLED. The pixel circuit further includes a second initialization module 120, a data writing module 130, a light emitting control module 140, and a storage module 150.
The second initialization module 120 includes a control terminal, a first terminal, and a second terminal; a control terminal of the second initialization module 120 is connected to the second initialization control signal S2, a first terminal of the second initialization module 120 is connected to the first initialization voltage signal Vref1, and a second terminal of the second initialization module 120 is electrically connected to a gate of the driving transistor DTFT; the second initialization module 120 is configured to turn on during an initialization phase, so that the first initialization voltage signal Vref1 completes initialization of the gate of the driving transistor DTFT.
The data writing module 130 includes a control terminal, a first terminal, a second terminal, a third terminal and a fourth terminal, the control terminal of the data writing module 130 is connected to the data writing control signal Sd, the first terminal is connected to the data signal Vdata, the second terminal is electrically connected to the first pole of the driving transistor DTFT, the third terminal is electrically connected to the second pole of the driving transistor DTFT, and the fourth terminal is electrically connected to the gate of the driving transistor DTFT. The data writing module 130 is configured to be turned on in a data writing phase, and write the data signal Vdata into the gate of the driving transistor DTFT along the directions of the first pole, the second pole, and the gate of the driving transistor DTFT.
The light emitting control module 140 includes a first control terminal, a second control terminal, a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The first control terminal and the second control terminal of the light emitting control module 140 are both connected to the light emitting control signal EM, a part of circuits in the light emitting control module 140 is connected in series between the first power signal VDD and the first pole of the driving transistor DTFT, and another part of circuits is connected in series between the second pole of the driving transistor DTFT and the anode of the light emitting device OLED. The light emission control module 140 is turned on during a light emission period to provide a voltage to the first electrode of the driving transistor DTFT and provide a path between the driving transistor DTFT and the light emitting device OLED, so as to transmit a driving current generated by the driving transistor DTFT to the light emitting device OLED. And the cathode of the light-emitting device OLED is connected with a second power supply signal VSS.
The memory module 150 includes a first terminal and a second terminal, the first terminal of the memory module 150 is connected to the first power signal VDD, and the second terminal is electrically connected to the gate of the driving transistor DTFT. The storage module 150 is configured to store a gate potential of the driving transistor DTFT to ensure that the gate potential of the driving transistor DTFT is stable in a light emitting phase, so that the driving transistor DTFT generates a stable driving current.
In the above embodiments, the driving transistor DTFT and the first transistor M1 may be P-type transistors or N-type transistors. For convenience of explanation, a driving process of the pixel circuit in the case where the driving transistor DTFT and the first transistor M1 are P-type transistors will be described below.
Fig. 2 is a schematic diagram of a driving timing sequence of a pixel circuit according to an embodiment of the invention. With reference to fig. 1 and fig. 2, the driving process of the pixel circuit is as follows:
the initialization phase T1 includes a first initialization phase T11 and a second initialization phase T12. In the first initialization period T11, the first initialization control signal S1 is at a low level, and the second initialization control signal S2, the data write control signal Sd, and the emission control signal EM are all at a high level. The first initialization control signal S1 controls the first initialization module 110 (the first transistor M1) to be turned on, the second initialization control signal S2 controls the second initialization module 120 to be turned off, the data write control signal Sd controls the data write module 130 to be turned off, and the emission control signal EM controls the emission control module 140 to be turned off. In this way, the first initialization control signal S1 initializes the anode of the light emitting device OLED through the first transistor M1 while controlling the first transistor M1 to be turned on, and provides a low level to the anode of the light emitting device OLED, so that the anode of the light emitting device OLED in a different operation state in the previous frame is forcibly reset. Compared with the prior art in which the reference voltage signal is connected to the first pole of the first transistor M1, the embodiment of the present invention does not need to set the reference voltage signal to be higher than the first initialization control signal S1 in order to ensure that the first transistor M1 is turned on, so that the first initialization control signal S1 (gate control signal VGL) is directly written into the anode of the light emitting device OLED, and a lower initialization voltage can be provided to the anode of the light emitting device OLED, thereby achieving a better initialization effect.
In the second initialization period T12, the second initialization control signal S2 is low, and the first initialization control signal S1, the data write control signal Sd, and the emission control signal EM are all high. The first initialization control signal S1 controls the first initialization module 110 (the first transistor M1) to be turned off, the second initialization control signal S2 controls the second initialization module 120 to be turned on, the data write control signal Sd controls the data write module 130 to be turned off, and the emission control signal EM controls the emission control module 140 to be turned off. In this way, the first initialization voltage signal Vref1 initializes the gate of the driving transistor DTFT through the second initialization module 120, so that the gate of the driving transistor DTFT in a different operation state in the previous frame is forcibly reset. The first initialization voltage signal Vref1 is at a low level to ensure that the residual potential displayed on the driving transistor DTFT in the previous frame is removed, the gate potential of the driving transistor DTFT is maintained by the capacitor Cst to prepare for the next data writing, and it is ensured that the driving transistor DTFT is turned on during the data writing period T2.
In the data writing period T2, the data writing control signal Sd is at a low level, and the first initialization control signal S1, the second initialization control signal S2, and the emission control signal EM are all at a high level. The first initialization control signal S1 controls the first initialization module 110 (the first transistor M1) to be turned off, the second initialization control signal S2 controls the second initialization module 120 to be turned off, the data write control signal Sd controls the data write module 130 to be turned on, and the emission control signal EM controls the emission control module 140 to be turned off. Thus, the data signal Vdata is written to the gate of the driving transistor DTFT via the source and drain of the driving transistor DTFT. Until the gate voltage of the driving transistor DTFT reaches Vdata + Vth, the driving transistor DTFT is closed; where Vth is the threshold voltage of the driving transistor DTFT.
In the light emission period T3, the light emission control signal EM is at a low level, and the first initialization control signal S1, the second initialization control signal S2, and the data write control signal Sd are all at a high level. The first initialization control signal S1 controls the first initialization module 110 (the first transistor M1) to be turned off, the second initialization control signal S2 controls the second initialization module 120 to be turned off, the data write control signal Sd controls the data write module 130 to be turned off, and the emission control signal EM controls the emission control module 140 to be turned on. Thus, the first pole of the driving transistor DTFT applies the first power signal VDD through the light emission control module 140, thereby generatingThe driving current flows into the anode of the light emitting device OLED, and drives the light emitting device OLED to emit light. At this time, since the gate voltage written to the driving transistor DTFT is Vdata + Vth, the driving current Ids generated by the driving transistor DTFT is Ids ═ μ C (W/2L)ox(Vdata+Vth-VDD-Vth)2＝(W/2L)μCox(VDD-Vdata)2Wherein W is a channel width, L is a channel length, μ is an electron mobility, CoxIs the channel capacitance per unit area. Channel width W, channel length L, electron mobility μ and channel capacitance per unit area CoxCan be considered as a constant. As can be seen from this, the gate voltage Vdata + Vth is obtained by performing threshold compensation on the gate voltage, and the influence of the threshold voltage Vth on the drive current Ids can be eliminated.
It should be noted that, in the above embodiments, the case where the initialization stage T1 is divided into two independent initialization sub-stages is exemplarily given, but the present invention is not limited thereto, and in other embodiments, the two initialization sub-stages may be performed simultaneously.
Fig. 3 is a circuit diagram of another pixel circuit according to an embodiment of the invention. Referring to fig. 3, on the basis of the foregoing embodiments, this embodiment provides a possible implementation manner for the configuration of each module, and optionally, the second initialization module 120 includes a second transistor M2, a gate of the second transistor M2 is connected to the second initialization control signal S2, a first pole of the second transistor M2 is connected to the first initialization voltage signal Vref1, and a second pole of the second transistor M2 is electrically connected to a gate of the driving transistor DTFT. By the arrangement, the circuit is simple in structure and easy to realize. Optionally, the channel type of the second transistor M2 is the same as that of the first transistor M1, and both the second transistor M2 and the first transistor M1 are P-type transistors, so that the first transistor M1 and the second transistor M2 can be manufactured in the same manufacturing process, and the manufacturing process is simplified.
With continued reference to FIG. 3, in one embodiment of the present invention, the data write module 130 includes a sixth transistor M6 and a seventh transistor M7. The gate of the sixth transistor M6 is connected to the data writing control signal Sd, the first pole of the sixth transistor M6 is connected to the data signal Vdata, and the second pole of the sixth transistor M6 is electrically connected to the first pole of the driving transistor DTFT; the gate of the seventh transistor M7 is connected to the data write control signal Sd, the first pole of the seventh transistor M7 is electrically connected to the gate of the driving transistor DTFT, and the second pole of the seventh transistor M7 is electrically connected to the second pole of the driving transistor DTFT. Optionally, the sixth transistor M6 and the seventh transistor M7 are the same as the transistors in the above embodiments in channel type, and are both P-type transistors, so that they are fabricated in the same fabrication process, and the fabrication process is simplified.
With continued reference to fig. 3, in one embodiment of the present invention, the light emitting control module 140 includes a fourth transistor M4 and a fifth transistor M5. A gate of the fourth transistor M4 is connected to the emission control signal EM, and the fourth transistor M4 is connected in series between the first power signal VDD and the first pole of the driving transistor DTFT; a gate of the fifth transistor M5 is connected to the emission control signal EM, and the fifth transistor M5 is connected in series between the second pole of the driving transistor DTFT and the anode of the light emitting device OLED. Optionally, the fourth transistor M4 and the fifth transistor M5 are the same as the transistors in the above embodiments in channel type, and are both P-type transistors, so that they are fabricated in the same fabrication process, and the fabrication process is simplified.
With continued reference to fig. 3, in one embodiment of the invention, the storage module 150 includes a capacitor Cst. A first terminal of the capacitor Cst is connected to the first power signal VDD, and a second terminal of the capacitor Cst is electrically connected to the gate of the driving transistor DTFT.
In summary, as the pixel circuit shown in fig. 3 constitutes a 7T1C structure, the first initialization control signal S1 can be a first scan signal, the second initialization control signal S2 can be a second scan signal, and the data writing control signal Sd can be a third scan signal, which are provided by the scan driving circuit. The driving process of the pixel circuit is explained below. The pixel circuit shown in fig. 3 can still adopt the driving sequence shown in fig. 2, and with reference to fig. 2 and fig. 3, the driving process of the pixel circuit includes:
the initialization phase T1 includes a first initialization phase T11 and a second initialization phase T12. In the first initialization period T11, the first initialization control signal S1 is at a low level, and the second initialization control signal S2, the data write control signal Sd, and the emission control signal EM are all at a high level. The first initialization control signal S1 controls the first transistor M1 to be turned on, the second initialization control signal S2 controls the second transistor M2 to be turned off, the data write control signal Sd controls the sixth transistor M6 and the seventh transistor M7 to be turned off, and the emission control signal EM controls the fourth transistor M4 and the fifth transistor M5 to be turned off. In this way, the first initialization control signal S1 controls the first transistor M1 to be turned on, and at the same time, the first and second poles of the first transistor M1 are also transmitted to the anode of the light emitting device OLED to initialize the anode of the light emitting device OLED, so that the anode of the light emitting device OLED in a different operation state in the previous frame is forcibly reset. The first transistor M1 is connected in such a way that the first initialization control signal S1 (gate control signal VGL) can be directly written into the anode of the light emitting device OLED, which is equivalent to providing a lower initialization voltage to the anode of the light emitting device OLED, so as to implement the reverse initialization of the anode of the light emitting device OLED, which is beneficial to improving the contrast.
In the second initialization period T12, the second initialization control signal S2 is low, and the first initialization control signal S1, the data write control signal Sd, and the emission control signal EM are all high. The first initialization control signal S1 controls the first transistor M1 to be turned off, the second initialization control signal S2 controls the second transistor M2 to be turned on, the data write control signal Sd controls the sixth transistor M6 and the seventh transistor M7 to be turned off, and the emission control signal EM controls the fourth transistor M4 and the fifth transistor M5 to be turned off. In this way, the first initialization voltage signal Vref1 is transmitted to the gate of the driving transistor DTFT through the first and second poles of the second transistor M2, initializes the gate of the driving transistor DTFT, and forcibly resets the gate of the driving transistor DTFT in a different operation state in the previous frame. The first initialization voltage signal Vref1 is at a low level (e.g., -7V, -10V, or-14V) to clear the residual potential displayed on the driving transistor DTFT in the previous frame, so as to ensure that the driving transistor DTFT is turned on during the data writing period T2.
In the data writing period T2, the data writing control signal Sd is at a low level, and the first initialization control signal S1, the second initialization control signal S2, and the emission control signal EM are all at a high level. The first initialization control signal S1 controls the first transistor M1 to be turned off, the second initialization control signal S2 controls the second transistor M2 to be turned off, the data write control signal Sd controls the sixth transistor M6 and the seventh transistor M7 to be turned on, and the emission control signal EM controls the fourth transistor M4 and the fifth transistor M5 to be turned off. Thus, the data signal Vdata is transmitted to the gate electrode of the driving transistor DTFT via the first pole of the sixth transistor M6, the second pole of the sixth transistor M6, the first pole of the driving transistor DTFT, the second pole of the seventh transistor M7, and the first pole of the seventh transistor M7, thereby writing the data signal Vdata into the gate electrode of the driving transistor DTFT until the gate voltage of the driving transistor DTFT reaches Vdata + Vth, and the driving transistor DTFT is turned off; the gate voltage of the driving transistor DTFT is stored by the capacitor Cst.
In the light emission period T3, the light emission control signal EM is at a low level, and the first initialization control signal S1, the second initialization control signal S2, and the data write control signal Sd are all at a high level. The first initialization control signal S1 controls the first transistor M1 to be turned off, the second initialization control signal S2 controls the second transistor M2 to be turned off, the data write control signal Sd controls the sixth transistor M6 and the seventh transistor M7 to be turned off, and the emission control signal EM controls the fourth transistor M4 and the fifth transistor M5 to be turned on. Thus, the turn-on of the light emission control module 140 provides a path between the first power signal VDD, the driving transistor DTFT, and the light emitting device OLED. The first power signal VDD is applied to the first pole of the driving transistor DTFT through the first pole and the second pole of the fourth transistor M4, so that the driving transistor DTFT generates a driving current, and the driving current flows into the anode of the light emitting device OLED through the first pole and the second pole of the fifth transistor M5, so as to drive the light emitting device OLED to emit light.
On the basis of the above embodiments, there are optionally a plurality of ways to arrange the first transistor M1 in the first initialization module 110, and a few of them will be described below.
With continued reference to fig. 1, in one embodiment, optionally the first transistor M1 is a P-type transistor with a gate of the first transistor M1 electrically connected to a first pole thereof. The first initialization control signal S1 is active low. In this embodiment, the first initialization control signal S1 is used to control the first transistor M1 to be turned on and to initialize the anode of the light emitting device OLED. It is understood that the lower the voltage of the first initialization control signal S1, the more beneficial the effect of initializing the anode of the light emitting device OLED; preferably, the voltage of the first initialization control signal S1 is lower than the second power signal VSS.
Fig. 4 is a circuit diagram of another pixel circuit according to an embodiment of the invention. Referring to fig. 4, in another embodiment, the first transistor M1 is an N-type transistor, and the gate of the first transistor M1 is electrically connected to the second pole thereof. The first initialization control signal S1 is low. Unlike the above-described embodiment, the first initialization control signal S1 is not electrically connected to the gate of the first transistor M1, and the gate of the first transistor M1 is connected to the anode of the light emitting device OLED. In order to ensure the conduction of the first transistor M1, the voltage of the first initialization control signal S1 needs to be lower than the anode voltage of the light emitting device OLED, so that the conduction of the first transistor M1 can be controlled, and the effect of initializing the anode of the light emitting device OLED can be ensured. It can be understood that the pixel circuit shown in fig. 4 can still be driven by the driving timing shown in fig. 2, and the driving process is similar to the foregoing driving process and is not described herein again.
Fig. 5 is a circuit diagram of another pixel circuit according to an embodiment of the invention. Referring to fig. 5, on the basis of the above embodiments, optionally, the pixel circuit further includes:
the cathode initialization module 170 initializes the anode and the cathode of the light emitting device OLED at the same time, thereby achieving a better initialization effect. The cathode initialization module 170 includes a first terminal, a second terminal, a third terminal, and a fourth terminal; the cathode initialization module 170 has a first end connected to the fourth initialization control signal S4, a second end electrically connected to the cathode of the light emitting device OLED, a third end connected to the light emitting control signal EM, and a fourth end connected to the second power signal VSS. Illustratively, the cathode initialization module 170 includes: an eighth transistor M8 and a ninth transistor M9. The eighth transistor M8 is disposed in the same manner as the first initialization module 110. Specifically, a first pole of the eighth transistor M8 is switched in the fourth initialization control signal S4; a second pole of the eighth transistor M8 is electrically connected to a second pole of the ninth transistor M9 and serves as a second terminal of the cathode initialization module 170; a gate of the eighth transistor M8 is electrically connected to the first pole or the second pole of the eighth transistor M8 (fig. 5 exemplarily shows a case where the eighth transistor M8 is a P-type transistor, when the gate of the eighth transistor M8 is electrically connected to the first pole thereof); the gate of the ninth transistor M9 is connected to the emission control signal EM; a first pole of the ninth transistor M9 is connected to the second power signal VSS.
The operation mode of the eighth transistor M8 is similar to that of the first transistor M1, and thus is not described herein. The ninth transistor M9 is provided because, in order to ensure that the cathode initialization module 170 can initialize the cathode of the light emitting device OLED, the cathode of the light emitting device OLED needs to be disconnected from the second power signal VSS in the initialization stage, and the ninth transistor M9 is controlled to be disconnected by the emission control signal EM, so that the path between the light emitting device OLED and the second power signal VSS can be effectively cut off.
In summary, the pixel circuit shown in fig. 5 constitutes a 9T1C structure. For the driving process of the pixel circuit, it should be noted that, when the light emitting device OLED is initialized, the anode and the cathode of the light emitting device OLED are both initialized by applying a low level, and in order to ensure the initialization effect, the fourth initialization control signal applied to the cathode of the light emitting device OLED should be higher than the first initialization control signal S1 applied to the anode of the light emitting device OLED, so that the light emitting device OLED can be reversely biased, and the initialization effect is improved.
On the basis of the above embodiments, optionally, the first initialization control signal S1, the second initialization control signal S2, or the third initialization control signal S3 is multiplexed into the fourth initialization control signal S4, so that the number of control signal lines can be reduced, which is advantageous to simplify the wiring of the display panel; meanwhile, the design of the scanning driving circuit can be simplified by reducing the number of the control signal lines, and the narrow frame design of the display panel is facilitated.
Fig. 6 is a circuit diagram of another pixel circuit according to an embodiment of the invention. On the basis of the foregoing embodiments, in this embodiment, a third initialization module 160 is optionally added to the pixel circuit. Referring to fig. 6, the third initialization module 160 includes a control terminal, a first terminal, and a second terminal; a control terminal of the third initialization module 160 is connected to the third initialization control signal S3, a first terminal of the third initialization module 160 is connected to the second initialization voltage signal Vref2, and a second terminal of the third initialization module 160 is electrically connected to the first pole of the driving transistor DTFT; the third initialization module 160 is used for initializing the first pole of the driving transistor DTFT.
In the conventional pixel circuit, when initializing the driving transistor DTFT, the gate is usually initialized, and the source is placed in a floating state. The insufficient reset of the driving transistor DTFT caused by this causes a problem that the display panel has an afterimage phenomenon.
In the pixel circuit provided in this embodiment, by setting the second initialization module 120 and the third initialization module 160, the gate and the first electrode of the driving transistor DTFT can be initialized respectively, the hysteresis voltage of the driving transistor is reduced, the initialization of the driving transistor is completed, the gate and the source of the driving transistor DTFT in different working states in the previous frame are forced to reset, the influence caused by the picture in the previous frame is reduced, and the afterimage can be improved.
With continued reference to fig. 6, on the basis of the foregoing embodiments, optionally, the third initialization module 160 includes: a third transistor M3; the gate of the third transistor M3 is connected to the third initialization control signal S3, the first pole of the third transistor M3 is connected to the second initialization voltage signal Vref2, and the second pole of the third transistor M3 is electrically connected to the first pole of the driving transistor DTFT.
In summary, the pixel circuit shown in fig. 6 has an 8T1C structure, and the driving process of the pixel circuit will be described below. Fig. 7 is a schematic diagram of a driving timing sequence of another pixel circuit according to an embodiment of the invention. In the driving process of the pixel circuit in this embodiment, in conjunction with fig. 6 and 7, a third initialization period T13 is added to the initialization period T1.
In the third initialization period T13, the third initialization control signal S3 is low, and the first initialization control signal S1, the second initialization control signal S2, the data write control signal Sd, and the emission control signal EM are all high. The first initialization control signal S1 controls the first transistor M1 to be turned off, the second initialization control signal S2 controls the second transistor M2 to be turned off, the third initialization control signal S3 controls the third transistor M3 to be turned on, the data write control signal Sd controls the sixth transistor M6 and the seventh transistor M7 to be turned off, and the emission control signal EM controls the fourth transistor M4 and the fifth transistor M5 to be turned off. In this way, the second initialization voltage signal Vref2 is transmitted to the first electrode of the driving transistor DTFT through the first and second electrodes of the third transistor M3, and initializes the first electrode of the driving transistor DTFT, thereby resetting the first electrode of the driving transistor DTFT in a different operation state in the previous frame.
In other periods, the third initialization control signal S3 is always kept at a high level, and controls the third transistor M3 to be turned off, thereby not functioning. The states of other signals in other time periods are the same as those in the foregoing embodiments, and for the driving processes of the pixel circuits in other phases, reference may be made to the foregoing embodiments, and details are not described here again.
The above embodiment exemplarily shows the first initialization module 110, the second initialization module 120 and the third initialization module 160 to initialize at different time periods in the initialization stage T1, but is not intended to limit the present invention. Alternatively, the valid times of the first initialization control signal S1, the second initialization control signal S2, and the third initialization control signal S3 may at least partially overlap.
In one embodiment of the present invention, optionally, the first initialization control signal S1 is multiplexed into the second initialization control signal S2; and/or the first initialization control signal S1 is multiplexed into the third initialization control signal S3. By the arrangement, the number of control signal lines can be reduced, and the simplification of the wiring of the display panel is facilitated; meanwhile, the design of the scanning driving circuit can be simplified by reducing the number of the control signal lines, and the narrow frame design of the display panel is facilitated. Alternatively, the data writing control signal Sd is multiplexed into the first initialization control signal S1, and since the first initialization module 110 only needs to initialize the light emitting device OLED before the light emitting period T3, the initialization of the light emitting device OLED may also be performed simultaneously with the data writing.
Fig. 8 is a circuit diagram of another pixel circuit according to an embodiment of the invention. Referring to fig. 8, in an embodiment of the present invention, optionally, the first initialization control signal S1 is multiplexed into the second initialization control signal S2, so that a driving timing diagram of the pixel circuit is as shown in fig. 9, and a specific driving process is similar to that of the foregoing embodiment and is not repeated here. Fig. 9 illustrates an example in which the first initialization control signal S1 is valid for a time period prior to the third initialization control signal S3, but is not intended to limit the present invention. In other embodiments, the second initialization control signal S2 may also be set to be valid for a time prior to the first initialization control signal S1; alternatively, the two initialization control signals are set to overlap at least partially in active time.
Fig. 10 is a circuit diagram of another pixel circuit according to an embodiment of the invention. Referring to fig. 10, in an embodiment of the present invention, optionally, the first initialization control signal S1 is multiplexed into the third initialization control signal S3, so that a driving timing diagram of the pixel circuit is as shown in fig. 11, and a specific driving process is similar to that of the foregoing embodiment and is not repeated here.
Fig. 12 is a circuit diagram of another pixel circuit according to an embodiment of the invention. Referring to fig. 10, in one embodiment of the present invention, the first initialization control signal S1 is optionally multiplexed into the second initialization control signal S2 and the third initialization control signal S3. In this way, as shown in fig. 13, the driving timing chart of the pixel circuit is such that all initialization operations are completed in the same time (initialization period T1). The preparation time before the light-emitting device OLED emits light can be reduced, and therefore high-frequency refreshing can be achieved. As can be seen, the first initialization control signal S1 may be a first scan signal, the data write control signal Sd may be a second scan signal, and the pulse widths of the first scan signal and the second scan signal are the same, and the second scan signal of the previous stage may be multiplexed into the first scan signal of the next stage, so that compared with the conventional 7T1C pixel circuit, the embodiment of the present invention does not need to add a new signal line, and is more practical.
Fig. 14 is a circuit diagram of another pixel circuit according to an embodiment of the invention. Referring to fig. 14, in an embodiment of the present invention, optionally, the second initialization control signal S2 is multiplexed into the third initialization control signal S3; the data write control signal Sd is multiplexed into the first initialization control signal S1. In this way, as shown in fig. 15, the driving timing chart of the pixel circuit is such that the initialization of the gate and the first electrode of the driving transistor DTFT is completed at the same time; the initialization of the light emitting device OLED is completed simultaneously with the data writing of the gate electrode of the driving transistor DTFT.
With continued reference to fig. 14, in addition to the above embodiments, optionally, the gate of the third transistor M3 is electrically connected to the first pole thereof, so as to form a diode connection manner. The third initialization control signal S3 is multiplexed into the second initialization voltage signal. The third transistor M3 is a P-type transistor, and when the second voltage of the third transistor M3 is higher than the voltage of the third initialization control signal S3, the third transistor M3 is turned on, and conversely, the third transistor M3 is turned off. That is, the third initialization control signal S3 is used to control the third transistor M3 to be turned on and also to initialize the first electrode of the driving transistor DTFT, thereby being beneficial to reducing the number of signal lines, simplifying the pixel circuit structure, enhancing the practicability, and facilitating the wiring of the display panel. In addition, for the second initialization module 120, in order to ensure reliable turn-on thereof, it is required to set the voltage of the first initialization voltage signal Vref1 to be greater than or equal to the second initialization control signal S2, and then the voltage of the first initialization voltage signal Vref1 is greater than or equal to the third initialization control signal S3. Further, when the P-type driving transistor DTFT is initialized, the voltage for initializing the first pole is lower than the voltage for initializing the gate electrode of the P-type driving transistor DTFT, so as to ensure that the gate-source voltage Vgs of the driving transistor DTFT is greater than or equal to 0, which is equivalent to performing reverse bias initialization on the driving transistor DTFT, thereby facilitating the driving transistor DTFT to realize sufficient reset, releasing holes trapped at the TFT channel interface when the device is turned on, effectively reducing the hysteresis voltage of the driving transistor DTFT, facilitating the improvement of the image sticking problem, and improving the display effect of the display panel.
In one embodiment of the present invention, the first initialization voltage signal Vref1 is optionally multiplexed into the second initialization voltage signal Vref 2. With this arrangement, the second initialization voltage signal Vref2 does not need to be additionally provided, which is advantageous for simplifying the wiring of the display panel.
In the above embodiments, the driving transistor DTFT, the first transistor M1, the second transistor M2, the third transistor M3, the fourth transistor M4, the fifth transistor M5, the sixth transistor M6, and the seventh transistor M7 are all P-type transistors, but the present invention is not limited thereto, and in other embodiments, some or all of the transistors may be N-type transistors as needed.
Fig. 16 is a circuit diagram of another pixel circuit according to an embodiment of the invention. As shown in fig. 16, the driving transistor DTFT, the second transistor M2, the fourth transistor M4, the fifth transistor M5, the sixth transistor M6, and the seventh transistor M7 are all N-type transistors. Fig. 16 exemplarily shows a case where the first transistor M1 is a P-type transistor, and the gate of the first transistor M1 is electrically connected to the first pole thereof. In other embodiments, the first transistor M1 may be replaced by an N-type transistor, and the gate thereof is electrically connected to the second pole.
Fig. 17 is a schematic diagram of a driving timing sequence of another pixel circuit according to an embodiment of the invention. As can be seen from fig. 17, since the driving signal is active at a high level for the N-type transistor, compared with the driving timing (fig. 2) when the pixel circuits are all formed by P-type transistors, the signals in fig. 17 except the first initialization control signal S1 are only active at a low level and active at a high level, and the time periods are not changed, for the pixel circuit in fig. 16, the driving process is similar to that when the pixel circuits are all formed by P-type transistors, and is not repeated here.
The above embodiments have described the 7T1C structure and the 8T1C structure by way of example, but are not intended to limit the present invention. For example, the embodiment of the present invention further provides a pixel circuit with a 3T1C structure, which is described below.
Fig. 18 is a circuit diagram of another pixel circuit according to an embodiment of the invention. As shown in fig. 18, the pixel circuit includes: a driving transistor DTFT, a light emitting device OLED, a first initialization module 110, a data writing module 130, and a storage module 150.
Here, the first initialization module 110 is connected to the anode of the light emitting device OLED for example. The first initialization module 110 includes a first transistor M1, a gate of the first transistor M1 is electrically connected to the first pole and is connected to the first initialization control signal S1, and a second pole of the first transistor M1 is electrically connected to the anode of the light emitting device OLED. The data writing module 130 includes a data writing transistor ST, a gate of the data writing transistor ST is connected to a data writing control signal Sd, a first pole is connected to a data signal Vdata, and a second pole is electrically connected to a gate of the driving transistor DTFT. The memory module 150 includes a capacitor Cst, a first terminal of the capacitor Cst is connected to the first power signal VDD, and a second terminal of the capacitor Cst is electrically connected to the gate of the driving transistor DTFT.
In the driving process, the pixel circuit provided in this embodiment only needs to ensure that the valid time of the first initialization control signal S1 is earlier than the valid time of the data writing control signal Sd. This is because the data writing module 130 is composed of only one data writing transistor ST, and when the data signal Vdata is written into the gate of the driving transistor DTFT through the data writing transistor ST, the driving transistor DTFT is turned on to generate a driving current, so as to drive the light emitting device OLED to emit light. Therefore, the light emitting device OLED is initialized between emitting light to ensure that the initialization is effective.
The embodiment of the invention also provides a display panel. Fig. 19 is a schematic structural diagram of a display panel according to an embodiment of the present invention. Referring to fig. 19, the display panel includes the pixel circuit 10 provided in any embodiment of the present invention, and the technical principle and the resulting effect are similar and will not be described again.
With continued reference to fig. 19, the display panel optionally further includes a plurality of first initialization control signal lines 20 and a plurality of data lines 30. The first initialization control signal line 20 supplies a first initialization control signal to the pixel circuit 10, and the data line 30 supplies a data signal to the pixel circuit 10.
With continued reference to fig. 19, optionally, the display panel further includes a scan driving circuit 1, and the scan driving circuit 1 is located in a non-display region of the display panel. The plurality of first initialization control signal lines 20 are electrically connected to the scan driving circuit 1, and the first initialization control signals are provided by the scan driving circuit 1.
The embodiment of the invention also provides a driving method of the pixel circuit, which is suitable for the pixel circuit provided by any embodiment of the invention, and the step of executing the first initialization control signal to control the first initialization module to be conducted so as to enable the first initialization control signal to initialize the light-emitting device is performed. The embodiment of the invention realizes the initialization of the light-emitting device, completes the reset of the light-emitting device and avoids the influence of the previous frame on the current frame. The first transistors are simultaneously controlled to be turned on and the light emitting devices are initialized by the first initialization control signal, so that the number of signal lines in the pixel circuit is reduced. In addition, compared with the scheme of initializing the light-emitting device by adopting the reference voltage in the prior art, the embodiment of the invention can initialize the anode of the light-emitting device by using lower voltage or initialize the cathode of the light-emitting device by using higher voltage, thereby effectively reducing the luminous brightness of the light-emitting device when the gray scale is low, being beneficial to improving the contrast of the display panel and improving the display effect.
Fig. 20 is a flowchart illustrating a driving method of a pixel circuit according to an embodiment of the invention. Referring to fig. 20, the driving method of the pixel circuit includes:
and S110, the first initialization control signal controls the first initialization module to be conducted so that the first initialization control signal initializes the light emitting device.
And S120, the second initialization control signal controls the second initialization module to be conducted so that the first initialization voltage signal initializes the grid of the driving transistor.
The two steps (S110 and S120) together constitute an initialization phase for driving the pixel circuit. The initialization sequence given in this embodiment is not intended to limit the present invention, and in practical application, the sequence of the above steps may be adjusted or combined according to actual requirements. Optionally, the initialization phase may further comprise the step of initializing the first pole of the drive transistor.
And S130, controlling the data writing module to be conducted by the data writing control signal so as to write the data signal into the grid electrode of the driving transistor. This step constitutes the data writing phase of driving the pixel circuits.
And S140, controlling the light-emitting control module to be conducted by the light-emitting control signal so as to enable the driving transistor to generate driving current and drive the light-emitting device to emit light. This step constitutes the light emitting stage of driving the pixel circuit.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims (10)

1. A pixel circuit, comprising:
a driving transistor for generating a driving current in response to a data signal;
a light emitting device connected in series with the driving transistor for emitting light in response to the driving current;
the first initialization module comprises a first transistor, wherein a first pole of the first transistor is connected to a first initialization control signal, a second pole of the first transistor is electrically connected with the anode of the light-emitting device, and a grid electrode of the first transistor is electrically connected with the first pole or the second pole of the first transistor; the first initialization control signal is used to initialize the anode of the light emitting device.
2. The pixel circuit according to claim 1, wherein the first transistor is a P-type transistor, and a gate of the first transistor is electrically connected to a first pole of the first transistor;
or, the first transistor is an N-type transistor, and a gate of the first transistor is electrically connected to the second pole of the first transistor.
3. The pixel circuit according to claim 1, wherein a first pole of the driving transistor is configured to be connected to a first power signal, and a second pole of the driving transistor is configured to be electrically connected to the light emitting device;
the pixel circuit further includes:
the second initialization module comprises a control end, a first end and a second end; a control end of the second initialization module is connected with a second initialization control signal, a first end of the second initialization module is connected with a first initialization voltage signal, and a second end of the second initialization module is electrically connected with a grid electrode of the driving transistor; the second initialization module is used for initializing the grid electrode of the driving transistor;
the third initialization module comprises a control end, a first end and a second end; a control end of the third initialization module is connected to a third initialization control signal, a first end of the third initialization module is connected to a second initialization voltage signal, and a second end of the third initialization module is electrically connected to the first pole of the driving transistor; the third initialization module is used for initializing the first pole of the driving transistor.
4. The pixel circuit of claim 3, wherein the second initialization module comprises: a second transistor; a grid electrode of the second transistor is connected with a second initialization control signal, a first pole of the second transistor is connected with a first initialization voltage signal, and a second pole of the second transistor is electrically connected with a grid electrode of the driving transistor;
the third initialization module includes: a third transistor; the grid electrode of the third transistor is connected with a third initialization control signal, the first pole of the third transistor is connected with a second initialization voltage signal, and the second pole of the third transistor is electrically connected with the first pole of the driving transistor.
5. The pixel circuit according to claim 4, wherein a gate of the third transistor and a first pole or a second pole of the third transistor are electrically connected, and the third initialization control signal is multiplexed into the second initialization voltage signal; preferably, the third transistor is a P-type transistor, and a gate of the third transistor is electrically connected to a first pole of the third transistor.
6. The pixel circuit according to claim 4, wherein the first initialization control signal is multiplexed into the second initialization control signal;
and/or the first initialization control signal is multiplexed into the third initialization control signal.
7. The pixel circuit according to claim 1, further comprising: a light emission control module; the light emitting control module comprises a fourth transistor and a fifth transistor;
a grid electrode of the fourth transistor is connected with a light-emitting control signal, and the fourth transistor is connected between a first power supply signal and the first pole of the driving transistor in series;
the grid electrode of the fifth transistor is connected with the light-emitting control signal, and the fifth transistor is connected between the second pole of the driving transistor and the anode of the light-emitting device in series;
preferably, the pixel circuit further includes: a memory module comprising a first end and a second end; the first end of the storage module is connected to the first power supply signal; the second end of the storage module is electrically connected with the grid electrode of the driving transistor;
preferably, the storage module includes: and a first end of the capacitor is connected with the first power supply signal, and a second end of the capacitor is electrically connected with the grid electrode of the driving transistor.
8. The pixel circuit according to claim 1, further comprising: a data writing module; the data writing module comprises a sixth transistor and a seventh transistor;
a gate of the sixth transistor is connected to a data writing control signal, a first pole of the sixth transistor is connected to a data signal, and a second pole of the sixth transistor is electrically connected to the first pole of the driving transistor;
a gate of the seventh transistor is connected to the data write control signal, a first pole of the seventh transistor is electrically connected to the gate of the driving transistor, and a second pole of the seventh transistor is electrically connected to the second pole of the driving transistor;
preferably, the pixel circuit further includes: a cathode initialization module comprising a first end, a second end, a third end, and a fourth end; a first end of the cathode initialization module is connected with a fourth initialization control signal, a second end of the cathode initialization module is electrically connected with a cathode of the light-emitting device, a third end of the cathode initialization module is connected with a light-emitting control signal, and a fourth end of the cathode initialization module is connected with a second power supply signal;
preferably, the cathode initialization module includes: an eighth transistor and a ninth transistor; a first pole of the eighth transistor is connected to a fourth initialization control signal; a second pole of the eighth transistor is electrically connected with a second pole of the ninth transistor and serves as a second end of the cathode initialization module; a gate of the eighth transistor is electrically connected to the first or second pole of the eighth transistor; the grid electrode of the ninth transistor is connected with the light-emitting control signal; the first pole of the ninth transistor is connected to the second power supply signal.
9. A display panel comprising the pixel circuit according to any one of claims 1 to 8.
10. A driving method of a pixel circuit, the pixel circuit comprising: a driving transistor, a light emitting device and a first initialization module; the first initialization module comprises a first transistor, the grid electrode of the first transistor is electrically connected with the first electrode of the first transistor, the first electrode of the first transistor is connected with a first initialization control signal, and the second electrode of the first transistor is electrically connected with the light-emitting device; the first initialization control signal is used for initializing the light emitting device;
the driving method of the pixel circuit includes:
the first initialization control signal controls the first initialization module to be conducted so that the first initialization control signal initializes the light emitting device.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113763881A (en) * 2021-09-30 2021-12-07 合肥维信诺科技有限公司 Display device and driving method thereof
CN115398640A (en) * 2021-09-23 2022-11-25 京东方科技集团股份有限公司 Display substrate and display device
WO2024000380A1 (en) * 2022-06-30 2024-01-04 京东方科技集团股份有限公司 Pixel driving circuit and control method therefor, and display device
WO2024000325A1 (en) * 2022-06-29 2024-01-04 京东方科技集团股份有限公司 Pixel circuit, drive method and display apparatus

Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104575389A (en) * 2015-01-29 2015-04-29 京东方科技集团股份有限公司 Pixel circuit, driving method of pixel circuit, display panel and display device
CN104715718A (en) * 2013-12-11 2015-06-17 乐金显示有限公司 Pixel circuit of display device, organic light emitting display device and method for driving the same
CN104751777A (en) * 2013-12-31 2015-07-01 昆山工研院新型平板显示技术中心有限公司 Pixel circuit, pixel and AMOLED display device comprising pixels as well as driving method of AMOLED display device
CN105243986A (en) * 2015-11-12 2016-01-13 京东方科技集团股份有限公司 Pixel compensation circuit and drive method thereof, array substrate and display device
CN105679236A (en) * 2016-04-06 2016-06-15 京东方科技集团股份有限公司 Pixel circuit and driving method thereof, array substrate, display panel and display device
KR20160090442A (en) * 2015-01-21 2016-08-01 삼성디스플레이 주식회사 Organic Light Emitting Display Device
CN205541822U (en) * 2016-04-06 2016-08-31 京东方科技集团股份有限公司 Pixel circuit , array substrate , display panel and display device
CN106409229A (en) * 2016-10-24 2017-02-15 昆山国显光电有限公司 Pixel circuit and driving method thereof, and active matrix organic light emitting display
CN106652903A (en) * 2017-03-03 2017-05-10 京东方科技集团股份有限公司 OLED pixel circuit, driving method of OLED pixel circuit and display device
CN107833559A (en) * 2017-12-08 2018-03-23 合肥京东方光电科技有限公司 Pixel-driving circuit, organic electroluminescence display panel and image element driving method
CN107945737A (en) * 2017-11-27 2018-04-20 合肥京东方光电科技有限公司 Pixel compensation circuit, its driving method, display panel and display device
CN107993612A (en) * 2017-12-21 2018-05-04 信利（惠州）智能显示有限公司 A kind of AMOLED pixel-driving circuits and image element driving method
CN108962138A (en) * 2018-04-04 2018-12-07 信利（惠州）智能显示有限公司 Pixel circuit and its driving method and display device
CN110060637A (en) * 2019-05-28 2019-07-26 京东方科技集团股份有限公司 Pixel-driving circuit, driving method, display panel and display device
CN110520922A (en) * 2018-09-20 2019-11-29 京东方科技集团股份有限公司 Display driver circuit, method and display equipment
CN111105749A (en) * 2020-01-15 2020-05-05 京东方科技集团股份有限公司 Pixel circuit, pixel driving method and display device
CN111243515A (en) * 2020-03-19 2020-06-05 昆山国显光电有限公司 Pixel circuit, display panel and driving method of pixel circuit
CN111354314A (en) * 2020-03-16 2020-06-30 昆山国显光电有限公司 Pixel circuit, driving method of pixel circuit and display panel
US20200388214A1 (en) * 2017-08-25 2020-12-10 Boe Technology Group Co., Ltd. Pixel circuit and method of driving the same, display device

Patent Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104715718A (en) * 2013-12-11 2015-06-17 乐金显示有限公司 Pixel circuit of display device, organic light emitting display device and method for driving the same
CN104751777A (en) * 2013-12-31 2015-07-01 昆山工研院新型平板显示技术中心有限公司 Pixel circuit, pixel and AMOLED display device comprising pixels as well as driving method of AMOLED display device
KR20160090442A (en) * 2015-01-21 2016-08-01 삼성디스플레이 주식회사 Organic Light Emitting Display Device
CN104575389A (en) * 2015-01-29 2015-04-29 京东方科技集团股份有限公司 Pixel circuit, driving method of pixel circuit, display panel and display device
CN105243986A (en) * 2015-11-12 2016-01-13 京东方科技集团股份有限公司 Pixel compensation circuit and drive method thereof, array substrate and display device
CN105679236A (en) * 2016-04-06 2016-06-15 京东方科技集团股份有限公司 Pixel circuit and driving method thereof, array substrate, display panel and display device
CN205541822U (en) * 2016-04-06 2016-08-31 京东方科技集团股份有限公司 Pixel circuit , array substrate , display panel and display device
CN106409229A (en) * 2016-10-24 2017-02-15 昆山国显光电有限公司 Pixel circuit and driving method thereof, and active matrix organic light emitting display
CN106652903A (en) * 2017-03-03 2017-05-10 京东方科技集团股份有限公司 OLED pixel circuit, driving method of OLED pixel circuit and display device
US20200388214A1 (en) * 2017-08-25 2020-12-10 Boe Technology Group Co., Ltd. Pixel circuit and method of driving the same, display device
CN107945737A (en) * 2017-11-27 2018-04-20 合肥京东方光电科技有限公司 Pixel compensation circuit, its driving method, display panel and display device
CN107833559A (en) * 2017-12-08 2018-03-23 合肥京东方光电科技有限公司 Pixel-driving circuit, organic electroluminescence display panel and image element driving method
CN107993612A (en) * 2017-12-21 2018-05-04 信利（惠州）智能显示有限公司 A kind of AMOLED pixel-driving circuits and image element driving method
CN108962138A (en) * 2018-04-04 2018-12-07 信利（惠州）智能显示有限公司 Pixel circuit and its driving method and display device
CN110520922A (en) * 2018-09-20 2019-11-29 京东方科技集团股份有限公司 Display driver circuit, method and display equipment
CN110060637A (en) * 2019-05-28 2019-07-26 京东方科技集团股份有限公司 Pixel-driving circuit, driving method, display panel and display device
CN111105749A (en) * 2020-01-15 2020-05-05 京东方科技集团股份有限公司 Pixel circuit, pixel driving method and display device
CN111354314A (en) * 2020-03-16 2020-06-30 昆山国显光电有限公司 Pixel circuit, driving method of pixel circuit and display panel
CN111243515A (en) * 2020-03-19 2020-06-05 昆山国显光电有限公司 Pixel circuit, display panel and driving method of pixel circuit

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115398640A (en) * 2021-09-23 2022-11-25 京东方科技集团股份有限公司 Display substrate and display device
CN113763881A (en) * 2021-09-30 2021-12-07 合肥维信诺科技有限公司 Display device and driving method thereof
CN113763881B (en) * 2021-09-30 2024-03-26 合肥维信诺科技有限公司 Display device and driving method thereof
WO2024000325A1 (en) * 2022-06-29 2024-01-04 京东方科技集团股份有限公司 Pixel circuit, drive method and display apparatus
WO2024000380A1 (en) * 2022-06-30 2024-01-04 京东方科技集团股份有限公司 Pixel driving circuit and control method therefor, and display device

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