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CN-121999711-A - Pixel circuit and display panel

CN121999711ACN 121999711 ACN121999711 ACN 121999711ACN-121999711-A

Abstract

The invention discloses a pixel circuit and a display panel, and belongs to the technical field of display. The pixel circuit comprises an amplitude modulation module, a pulse width modulation module, a coupling module and a potential control module. The second connecting end of the coupling module is connected with the control end of the pulse width modulation module, the potential control module is connected with the first connecting end of the coupling module and is accessed into direct current voltage and display control signals, the potential control module is used for controlling the first connecting end to float in a pulse width data writing stage and a light-emitting stage, the display control signals jump to second data voltage required by the pulse width modulation module in the pulse width data writing stage and appear as ramp signals with monotonic voltage change after jumping to initial voltage of the ramp signals in the light-emitting stage, and the potential control module is also used for transmitting the direct current voltage to the first connecting end in other stages with voltage change of the display control signals. The embodiment of the invention can stabilize the voltage of the control end of the pulse width modulation module and improve the display image quality.

Inventors

  • ZHANG LIXIN
  • XU SHANGJUN

Assignees

  • 成都辰显光电有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (10)

  1. 1. A pixel circuit, which comprises a pixel circuit and a pixel electrode, characterized by comprising the following steps: The amplitude modulation module is connected with the light emitting device and used for generating a driving current according to the first data voltage and providing the driving current to the light emitting device in a light emitting stage; The pulse width modulation module is connected with the amplitude modulation module and used for controlling the time for stopping outputting the driving current according to the voltage of the control end of the pulse width modulation module; The coupling module comprises a first connecting end and a second connecting end, wherein the second connecting end is connected with the control end of the pulse width modulation module, and the coupling module is used for coupling voltage jump of the first connecting end to the control end of the pulse width modulation module; the display control device comprises a first connecting end, a potential control module, a voltage control module and a potential control module, wherein the first connecting end is connected with the potential control module, the potential control module is connected with a direct current voltage and a display control signal, the potential control module is used for controlling the first connecting end to float in a pulse width data writing stage and a light emitting stage so as to transmit relevant voltage of the display control signal to the first connecting end, the display control signal jumps to a second data voltage required by the pulse width modulation module in the pulse width data writing stage and is presented as a ramp signal with monotonically changing voltage after jumping to an initial voltage of the ramp signal in the light emitting stage, and the potential control module is also used for transmitting the direct current voltage to the first connecting end in other stages with voltage change of the display control signal.
  2. 2. The pixel circuit according to claim 1, wherein the potential control module includes: the control end of the switch unit is connected with a switch control signal, the first end of the switch unit is connected with the direct-current voltage, and the second end of the switch unit is connected with the first connecting end; The first end of the coupling unit is connected with the display control signal, and the second end of the coupling unit is connected with the first connecting end; Preferably, the switch unit comprises a first transistor connected between a first end and a second end of the switch unit, and a grid electrode of the first transistor is connected with a control end of the switch unit; The coupling unit comprises a first capacitor connected between a first end and a second end of the coupling unit.
  3. 3. The pixel circuit according to claim 2, wherein the potential control module further comprises a storage unit, a first end of the storage unit is connected with a fixed voltage signal, and a second end of the storage unit is connected with a control end of the switch unit; preferably, the memory cell includes a second capacitor connected between the first and second terminals of the memory cell.
  4. 4. The pixel circuit according to claim 2, wherein the potential control module further comprises a gate control unit connected to a control terminal of the switching unit for providing the switching control signal; preferably, the gate control unit includes: the switching control circuit comprises a switching unit, a first transmission subunit, a second transmission subunit, a first control unit and a second transmission subunit, wherein the switching unit is used for switching on or switching off a pulse width data writing stage; The second transmission subunit is used for responding to a third control signal when the pulse width data writing phase is finished or after the pulse width data writing phase is finished, controlling the switch control signal to jump to the conducting voltage of the switch unit, and responding to a fourth control signal before the pulse width data writing phase is started, controlling the switch control signal to jump to the conducting voltage of the switch unit; The third control signal controls the switch control signal to carry out voltage jump at a time earlier than the second control signal controls the switch control signal to carry out voltage jump; Preferably, the first transmission subunit comprises a second transistor and a third transistor, wherein the grid electrode of the second transistor is connected with the first control signal, the grid electrode of the third transistor is connected with the second control signal, the first poles of the second transistor and the third transistor are connected with a first voltage signal, and the second poles of the second transistor and the third transistor are connected with the control end of the switch unit; The second transmission subunit comprises a fourth transistor and a fifth transistor, wherein the grid electrode of the fourth transistor is connected with the third control signal, the grid electrode of the fifth transistor is connected with the fourth control signal, the first electrode of the fourth transistor and the first electrode of the fifth transistor are connected with a second voltage signal, the second electrode of the fourth transistor and the second electrode of the fifth transistor are connected with the control end of the switch unit, and the second voltage signal keeps the on voltage of the switch unit.
  5. 5. The pixel circuit of claim 4, wherein the pulse width modulation module is configured to control a voltage of a control terminal of the pulse width modulation module to be changed to a voltage related to the second data voltage according to a first scan signal and the display control signal in the pulse width data writing stage; The pulse width modulation module is used for responding to a light-emitting setting signal and outputting a first initialization signal in a light-emitting preparation stage, wherein the light-emitting preparation stage is positioned between the pulse width data writing stage and the light-emitting stage; The amplitude modulation module is used for transmitting a second initialization signal to an internal node of the amplitude modulation module in a first initialization stage and writing relevant voltage of the first data voltage into the internal node in an amplitude data writing stage, wherein the first initialization stage, the amplitude data writing stage and the pulse width data writing stage are sequentially carried out; And/or the pulse width modulation module is used for transmitting a third initialization signal to the control end of the pulse width modulation module in a second initialization stage, the second initialization stage is performed earlier than the pulse width data writing stage, and the moment of the fourth control signal for controlling the switch control signal to perform voltage jump is earlier than the starting moment of the second initialization stage.
  6. 6. The pixel circuit according to any one of claims 1-5, wherein the amplitude modulation module is configured to transmit a second initialization signal to an internal node of the amplitude modulation module during a first initialization phase and to write a relevant voltage of the first data voltage to the internal node during an amplitude data writing phase; or the pulse width modulation module is used for transmitting a third initialization signal to the control end of the pulse width modulation module in a second initialization stage, wherein the third initialization signal is multiplexed into the direct current voltage; or the pulse width modulation module is used for outputting a first initialization signal in a light-emitting preparation stage, and the first initialization signal is multiplexed into the direct-current voltage.
  7. 7. A display panel according to any one of claims 1 to 6, comprising a pixel circuit.
  8. 8. The display panel according to claim 7, wherein the display panel comprises a plurality of pixel circuits arranged in an array, wherein the display control signals of the pixel circuits in the same column are provided by the same data line; In the pulse width data writing stage corresponding to any pixel circuit, the voltage on the data line connected with the pixel circuit is changed from the second data voltage required by the pixel circuit in the previous row in the same column to the second data voltage required by the pixel circuit.
  9. 9. The display panel of claim 7, wherein for any one of the pixel circuits: the amplitude modulation module is used for transmitting a second initialization signal to an internal node of the amplitude modulation module in response to a second scanning signal in a first initialization stage, transmitting related voltage of a first data voltage to the internal node in response to a third scanning signal in an amplitude data writing stage, and generating a driving current according to the voltage of the internal node in response to a first light emitting control signal in a light emitting stage; the pulse width modulation module is used for responding to a fourth scanning signal in a second initialization stage and transmitting a third initialization signal to a control end of the pulse width modulation module, controlling the voltage of the control end of the pulse width modulation module to be changed into the relevant voltage of the second data voltage according to a first scanning signal and the display control signal in the pulse width data writing stage, responding to a light-emitting setting signal in a light-emitting preparation stage and outputting the first initialization signal, and controlling the time for stopping outputting the driving current by the amplitude modulation module according to the second light-emitting control signal and the display control signal in the light-emitting stage; The second initialization stage and the amplitude data writing stage are performed simultaneously, and the third scanning signal is multiplexed into the fourth scanning signal; the first initialization stage, the amplitude data writing stage, the pulse width data writing stage, the light-emitting preparation stage and the light-emitting stage are sequentially performed; The display panel comprises a plurality of pixel circuits which are arranged in an array, wherein the first scanning signal accessed by the pixel circuits in the nth row is used as the third scanning signal accessed by the pixel circuits in the (n+1) th row and the second scanning signal accessed by the pixel circuits in the (n+2) th row, n is a positive integer, all the pixel circuits are accessed to the same light-emitting setting signal, all the pixel circuits are accessed to the same first light-emitting control signal, and all the pixel circuits are accessed to the same second light-emitting control signal; Preferably, the display panel further comprises a scanning circuit, wherein the scanning circuit comprises a plurality of stages of shift registers which are connected in cascade, and the first scanning signals, the second scanning signals and the third scanning signals which are connected to the pixel circuits in the same row are provided by the shift registers in different stages in the scanning circuit.
  10. 10. The display panel according to claim 9, wherein in the pixel circuit, the potential control module includes a gate control unit for providing a switching control signal, the gate control unit includes a first transmission subunit and a second transmission subunit, the first transmission subunit is connected to the first control signal and the second control signal, and the second transmission subunit is connected to the third control signal and the fourth control signal; the fourth control signal controls the moment of voltage jump of each switch control signal to be earlier than the starting moment of the first initialization stage of the pixel circuits in the first row; preferably, the first scan signal accessed by the pixel circuit of the next row is multiplexed into the third control signal accessed by the pixel circuit of the current row.

Description

Pixel circuit and display panel Technical Field The present invention relates to the field of display technologies, and in particular, to a pixel circuit and a display panel. Background Referring to fig. 1, currently, in a pixel circuit for driving an M-LED by an analog pulse width modulation method, a current time control part 01 for controlling a light emitting period of a light emitting device L and a current magnitude control part 02 for controlling a magnitude of a driving current transmitted to the light emitting device L are generally included. The pixel operation is divided into a data writing phase and a light emitting phase. In the DATA writing stage, the DATA voltage DATA related to time control is coupled and transmitted to the control terminal N of the current time control part 01 through the capacitor C0. However, since the pixel circuits in the same column in the display panel are connected to one DATA line to obtain the DATA voltage DATA, voltage jump on the DATA line during the refreshing of the DATA line of the present row may affect the voltage of the control terminal N of the current time control portion 01 in the pixel circuits of the other row, or, voltage jump on the DATA line during the refreshing of the DATA line of the other row may also affect the voltage of the control terminal N of the current time control portion 01 in the pixel circuits of the present row. The voltage change at the control terminal N may cause the state of the driving transistor inside the current time control portion 01 to change, affecting the control of the light emission time, resulting in the occurrence of display quality problems. Disclosure of Invention The invention provides a pixel circuit and a display panel, which are used for stabilizing the voltage of a control end of a pulse width modulation module, ensuring the accurate control of the pixel circuit on the light emitting time of a light emitting device and improving the display image quality. In a first aspect, an embodiment of the present invention provides a pixel circuit, including: The amplitude modulation module is connected with the light emitting device and used for generating a driving current according to the first data voltage and providing the driving current to the light emitting device in a light emitting stage; The pulse width modulation module is connected with the amplitude modulation module and used for controlling the time for stopping outputting the driving current according to the voltage of the control end of the pulse width modulation module; The coupling module comprises a first connecting end and a second connecting end, wherein the second connecting end is connected with the control end of the pulse width modulation module, and the coupling module is used for coupling voltage jump of the first connecting end to the control end of the pulse width modulation module; the display control device comprises a first connecting end, a potential control module, a voltage control module and a potential control module, wherein the first connecting end is connected with the potential control module, the potential control module is connected with a direct current voltage and a display control signal, the potential control module is used for controlling the first connecting end to float in a pulse width data writing stage and a light emitting stage so as to transmit relevant voltage of the display control signal to the first connecting end, the display control signal jumps to a second data voltage required by the pulse width modulation module in the pulse width data writing stage and is presented as a ramp signal with monotonically changing voltage after jumping to an initial voltage of the ramp signal in the light emitting stage, and the potential control module is also used for transmitting the direct current voltage to the first connecting end in other stages with voltage change of the display control signal. Optionally, the potential control module includes: the control end of the switch unit is connected with a switch control signal, the first end of the switch unit is connected with the direct-current voltage, and the second end of the switch unit is connected with the first connecting end; The first end of the coupling unit is connected with the display control signal, and the second end of the coupling unit is connected with the first connecting end; Preferably, the switch unit comprises a first transistor connected between a first end and a second end of the switch unit, and a grid electrode of the first transistor is connected with a control end of the switch unit; The coupling unit comprises a first capacitor connected between a first end and a second end of the coupling unit. Optionally, the potential control module further comprises a storage unit, wherein a first end of the storage unit is connected with a fixed voltage signal, and a second end of the storage unit is connected with a control end of the switch unit; prefera