Pixel circuit

Abstract

The embodiment of the invention belongs to the display technology, and provides a pixel circuit. A reset circuit in the pixel circuit is connected with a control end of a second switch circuit in the PWM drive circuit through a first compensation circuit; the control end of the PAM drive circuit is connected with the reset circuit, the second compensation circuit and the second end of the second switching circuit. The light emitting circuit is connected with the PAM driving circuit. Threshold voltage compensation is carried out on the second switch circuit in the PWM drive circuit through the first compensation circuit, threshold voltage compensation is carried out on the PAM drive circuit through the second compensation circuit, the threshold voltage drift problem of TFTs in the PWM drive circuit and the PAM drive circuit can be solved, the current flowing through the micro light-emitting diode is more stable, and the service life of the micro light-emitting diode is prolonged. And the light-emitting duration and the light-emitting wavelength of the micro light-emitting diode are not changed, so that the display effect is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to display technology, and more specifically, to a pixel circuit. Background Art

[0002] Compared with active matrix organic light emitting diode (AMOLED), micro light emitting diode (Micro-LED, also known as μLED) has the advantages of smaller size, faster response speed, higher luminous efficiency, stronger stability and longer service life. Therefore, display panels built based on micro light emitting diodes are thin, light-saving, power-saving and self-luminous, and have attracted people's attention.

[0003] In the prior art, a display panel has a plurality of pixel circuits, each of which includes a micro-light emitting diode. The pixel circuit is usually driven by a combination of pulse width modulation (PWM) and pulse amplitude modulation (PAM). Through PWM, the light emission duration of the micro-light emitting diode can be controlled, thereby controlling the brightness perceived by the human eye. Through PAM, the light emission wavelength of the micro-light emitting diode can be controlled.

[0004] However, the pixel circuit includes a thin film transistor (TFT) for implementing PWM drive and PAM drive. After long-term use, the threshold voltage of TFT is prone to drift, resulting in changes in the light emission time and wavelength of the micro light emitting diode, resulting in poor display effect. Summary of the invention

[0005] An embodiment of the present application provides a pixel circuit for solving the problem in existing pixel circuits that a threshold voltage drift of a TFT is prone to occur after long-term use, resulting in changes in the light emission duration and wavelength of a micro light emitting diode, and poor display effects.

[0006] In a first aspect, an embodiment of the present application provides a pixel circuit, including:

[0007] A pulse width modulation (PWM) driving circuit, a first compensation circuit, a pulse amplitude modulation (PAM) driving circuit, a second compensation circuit, a reset circuit, and a light-emitting circuit; the PWM driving circuit includes a first switching circuit, a first capacitor, a second capacitor, and a second switching circuit;

[0008] A first end of the first switch circuit is connected to a PWM drive signal output end, a second end of the first switch circuit is connected to a first end of the first capacitor and a first end of the second capacitor respectively, a control end of the first switch circuit is connected to a first control signal output end, and a second end of the second capacitor is connected to a second control signal output end;

[0009] The second end of the first capacitor is connected to the control end of the second switch circuit, and the first end of the second switch circuit is connected to the first power supply end;

[0010] The reset circuit is connected to the control end of the second switch circuit through the first compensation circuit, and the second end of the second switch circuit is connected to the first compensation circuit;

[0011] The control end of the PAM driving circuit is connected to the reset circuit, the second compensation circuit, and the second end of the second switch circuit respectively, and the light emitting circuit is connected to the PAM driving circuit.

[0012] The beneficial effects of this embodiment are as follows: by connecting the first compensation circuit to the control end of the second switch circuit, the first compensation circuit performs threshold voltage compensation for the second switch circuit in the PWM drive circuit; and by connecting the second compensation circuit to the control end of the PAM drive circuit, the second compensation circuit performs threshold voltage compensation for the PAM drive circuit, which can solve the threshold voltage drift problem of TFT in the PWM drive circuit and the PAM drive circuit, making the current flowing through the micro light emitting diode more stable, and the light emission time and light emission wavelength of the micro light emitting diode will not change, thereby improving the display effect.

[0013] In some embodiments of the present application, the first compensation circuit includes a third switch circuit, and the reset circuit includes a fourth switch circuit;

[0014] The first end of the third switch circuit is connected to the control end of the second switch circuit, the second end of the third switch circuit is connected to the second end of the second switch circuit, and the control end of the third switch circuit is connected to the third control signal output end;

[0015] The control end of the fourth switch circuit is connected to the fourth control signal output end, the first end of the fourth switch circuit is connected to the second end of the third switch circuit, and the second end of the fourth switch circuit is connected to the reset signal output end.

[0016] Beneficial effects of this embodiment: When the third switch circuit and the fourth switch circuit are turned on, the reset signal of the reset voltage output by the reset signal output terminal passes through the fourth switch circuit and the third switch circuit in sequence, and reaches the control terminal of the second switch circuit, so that the voltage of the control terminal of the second switch circuit is the reset voltage, the second switch circuit is turned on, and the voltage of the control terminal of the second switch circuit is reset. Then the fourth switch circuit is disconnected, and the first power supply terminal applies a voltage to the control terminal of the second switch circuit through the second switch circuit and the third switch circuit, so that the voltage of the control terminal of the second switch circuit reaches the first compensation voltage, the second switch circuit is disconnected, and the threshold voltage compensation is completed. Then the third switch circuit is disconnected, the first switch circuit is turned on, and the PWM drive signal output terminal applies a voltage to the control terminal of the second switch circuit through the first switch circuit and the first capacitor to the first drive voltage, so as to realize voltage writing.

[0017] In some embodiments of the present application, the PAM driving circuit includes a fifth switch circuit, a third capacitor, a fourth capacitor, and a sixth switch circuit;

[0018] The second compensation circuit includes a seventh switch circuit;

[0019] The light emitting circuit comprises an eighth switch circuit and a micro light emitting diode;

[0020] The first end of the fifth switch circuit is connected to the first end of the fourth capacitor, the second end of the fifth switch circuit is connected to the PAM drive signal output end, and the control end of the fifth switch circuit is connected to the fifth control signal output end;

[0021] The second end of the fourth capacitor is respectively connected to the first end of the third capacitor and the control end of the sixth switch circuit, and the first power supply end is respectively connected to the second end of the third capacitor and the first end of the sixth switch circuit;

[0022] The first end of the fourth switch circuit is connected to the control end of the sixth switch circuit;

[0023] The first end of the seventh switch circuit is connected to the control end of the sixth switch circuit, the second end of the seventh switch circuit is connected to the second end of the sixth switch circuit, and the control end of the seventh switch circuit is connected to the sixth control signal output end;

[0024] The control end of the eighth switch circuit is connected to the switch signal output end, the first end of the eighth switch circuit is connected to the second end of the sixth switch circuit, and the second end of the eighth switch circuit is connected to the first end of the micro light emitting diode;

[0025] The second end of the micro light emitting diode is connected to the second power supply end.

[0026] The beneficial effect of this embodiment is as follows: when the fourth switch circuit is turned on, the reset signal of the reset voltage outputted from the reset signal output terminal passes through the fourth switch circuit in sequence to reach the control terminal of the sixth switch circuit, so that the voltage at the control terminal of the sixth switch circuit is the reset voltage and the sixth switch circuit is turned on, thereby realizing the voltage reset of the control terminal of the sixth switch circuit.

[0027] When the sixth switch circuit and the seventh switch circuit are turned on, the first power supply end applies a voltage to the control end of the sixth switch circuit through the sixth switch circuit and the seventh switch circuit, so that the voltage at the control end of the sixth switch circuit reaches the second compensation voltage, and the sixth switch circuit is disconnected to complete the threshold voltage compensation. Then the seventh switch circuit is disconnected, the fifth switch circuit is turned on, and the PAM drive signal output end applies a voltage to the control end of the sixth switch circuit to the second drive voltage through the fifth switch circuit and the fourth capacitor, and the sixth switch circuit is turned on to achieve voltage writing.

[0028] When the sixth switch circuit and the eighth switch circuit are turned on, the first power supply end or the second power supply end outputs current through the micro light emitting diode to drive the micro light emitting diode to emit light. After the second switch circuit is turned on, the first power supply end applies a voltage to the control end of the sixth switch circuit through the second switch circuit to the second compensation voltage, and the sixth switch circuit is turned off to stop the micro light emitting diode from emitting light.

[0029] In some embodiments of the present application, in the first reset stage, the third control signal output terminal outputs a control signal of a first level to turn on the third switch circuit;

[0030] The fourth control signal output terminal outputs a control signal of a first level to turn on the fourth switch circuit;

[0031] The control signal outputted by the second control signal output terminal maintains the first level for a preset period of time and then changes to the second level;

[0032] The reset signal output terminal outputs a reset signal of a reset voltage, and the reset signal passes through the fourth switch circuit and the third switch circuit in sequence to reach the control terminal of the second switch circuit, so that the voltage of the control terminal of the second switch circuit is the reset voltage and the second switch circuit is turned on.

[0033] The beneficial effects of this embodiment are as follows: in the first reset stage, the third switch circuit is turned on with the fourth switch circuit, and the reset signal passes through the fourth switch circuit and the third switch circuit in sequence to reach the control end of the second switch circuit, and the voltage at the control end of the second switch circuit is set to the reset voltage, thereby achieving voltage reset, thereby ensuring that in the subsequent first compensation stage, the voltage at the control end of the second switch circuit can be smoothly adjusted to the first compensation voltage.

[0034] In some embodiments of the present application, in a first compensation phase after the first reset phase, the third control signal output terminal outputs a control signal of a first level to turn on the third switch circuit;

[0035] The first power supply end applies a voltage to the control end of the second switch circuit through the second switch circuit and the third switch circuit. When the voltage at the control end of the second switch circuit reaches the first compensation voltage, the second switch circuit is disconnected.

[0036] The beneficial effects of this embodiment are as follows: in the first compensation stage, the second switch circuit and the third switch circuit are turned on, and the first power supply end applies a voltage to the control end of the second switch circuit through the second switch circuit and the third switch circuit, so that the voltage at the control end of the second switch circuit reaches the first compensation voltage, thereby completing the threshold voltage compensation.

[0037] In some embodiments of the present application, in a first driving voltage writing phase after the first compensation phase, the first control signal output terminal outputs a control signal of a first level to turn on the first switch circuit;

[0038] The control signal outputted by the PWM drive signal output terminal is maintained at the first level for a preset period of time and then changes to the second level;

[0039] The PWM driving signal output terminal applies a voltage to the first driving voltage to the control terminal of the second switching circuit through the first switching circuit and the first capacitor;

[0040] In a second resetting phase after the first driving voltage writing phase, the fourth control signal output terminal outputs a control signal of a first level to turn on the fourth switch circuit;

[0041] The reset signal output terminal outputs a reset signal of the reset voltage;

[0042] The reset signal sequentially passes through the fourth switch circuit to reach the control end of the sixth switch circuit, so that the voltage of the control end of the sixth switch circuit is the reset voltage and the sixth switch circuit is turned on.

[0043] Beneficial effects of this embodiment: During the first drive voltage writing stage, the first switch circuit is turned on, and the PWM drive signal output terminal applies a voltage to the control terminal of the second switch circuit through the first switch circuit and the first capacitor to achieve voltage writing. The first drive voltage is subsequently used to control the on and off of the second switch circuit, which can solve the problem of voltage threshold drift, ensure that the current flowing through the micro-LED is more stable, and the light emission time of the micro-LED will not change, thereby improving the display effect.

[0044] By turning on the fourth switch circuit in the second reset stage, the reset signal reaches the control end of the sixth switch circuit through the fourth switch circuit, and the voltage at the control end of the sixth switch circuit is set to the reset voltage, thereby achieving voltage reset, thereby ensuring that in the subsequent second compensation stage, the voltage at the control end of the sixth switch circuit can be smoothly adjusted to the second compensation voltage.

[0045] In some embodiments of the present application, in a second compensation phase after the second reset phase, the sixth control signal output terminal outputs a control signal of a first level to turn on the seventh switch circuit;

[0046] The first power supply end applies a voltage to the control end of the sixth switch circuit through the sixth switch circuit and the seventh switch circuit. When the voltage of the control end of the sixth switch circuit reaches the second compensation voltage, the sixth switch circuit is disconnected.

[0047] The beneficial effects of this embodiment are as follows: in the second compensation stage, the sixth switch circuit and the seventh switch circuit are turned on, and the first power supply end applies a voltage to the control end of the sixth switch circuit through the sixth switch circuit and the seventh switch circuit, so that the voltage at the control end of the sixth switch circuit reaches the second compensation voltage, thereby completing the threshold voltage compensation.

[0048] In some embodiments of the present application, in the second driving voltage writing stage after the second compensation stage, the fifth control signal output terminal outputs a control signal of a first level to turn on the fifth switch circuit;

[0049] The control signal output by the PAM drive signal output terminal is to maintain the second level for a preset time and then change to the first level, and the PAM drive signal output terminal applies a voltage to the control terminal of the sixth switch circuit through the fifth switch circuit and the fourth capacitor to the second drive voltage, and the sixth switch circuit is turned on;

[0050] In the light emitting stage after the second driving voltage writing stage, the switch signal output terminal outputs a control signal of a first level to turn on the eighth switch circuit;

[0051] The first power supply end or the second power supply end outputs a current which passes through the micro light emitting diode to drive the micro light emitting diode to emit light;

[0052] The level of the control signal output by the second control signal output terminal gradually changes from the second level to the first level, so that the voltage of the control terminal of the second switch circuit gradually changes to the first driving voltage, and the second switch circuit is turned on;

[0053] The first power supply end applies a voltage to the control end of the sixth switch circuit through the second switch circuit, up to the second compensation voltage, the sixth switch circuit is disconnected, and the micro light emitting diode stops emitting light.

[0054] Beneficial effects of this embodiment: During the second drive voltage writing stage, the fifth switch circuit is turned on, and the PAM drive signal output terminal applies a voltage to the control terminal of the sixth switch circuit through the fifth switch circuit and the fourth capacitor to the second drive voltage, and the sixth switch circuit is turned on to achieve voltage writing. The second drive voltage is subsequently used to control the on and off of the sixth switch circuit, which can solve the problem of voltage threshold drift, ensure that the current flowing through the micro-LED is more stable, and the light emission wavelength of the micro-LED will not change, thereby improving the display effect.

[0055] By turning on the sixth switch circuit and the eighth switch circuit during the light-emitting stage, the first power supply end or the second power supply end outputs current through the micro-light-emitting diode, so that the micro-light-emitting diode can emit light, and in the process of the micro-light-emitting diode emitting light, it will not be affected by the threshold voltage drift, and the light-emitting duration and wavelength of the micro-light-emitting diode will not change, thereby improving the display effect. In addition, the first power supply end applies a voltage to the control end of the sixth switch circuit through the second switch circuit to the second compensation voltage, the sixth switch circuit is disconnected, and the micro-light-emitting diode stops emitting light, so that the light-emitting duration of the micro-light-emitting diode can be controlled.

[0056] In some embodiments of the present application, the third control signal output terminal outputs a control signal of a first level in the first reset stage and the first compensation stage, and outputs a control signal of a second level in the first drive voltage writing stage, the second reset stage, the second compensation stage, the second drive voltage writing stage, and the light-emitting stage.

[0057] The beneficial effects of this embodiment are as follows: by outputting a control signal of the first level in the first reset phase, the voltage at the control end of the second switch circuit can be reset; by outputting a control signal of the first level in the first compensation phase, the voltage at the control end of the second switch circuit can reach the first compensation voltage, thereby completing the threshold voltage compensation.

[0058] In some embodiments of the present application, the sixth control signal output terminal outputs a control signal of the first level in the second compensation stage, and outputs a control signal of the second level in the first reset stage, the first compensation stage, the first drive voltage writing stage, the second reset stage, the second drive voltage writing stage, and the light-emitting stage.

[0059] Beneficial effect of this embodiment: by outputting the control signal of the first level in the second compensation stage, the voltage at the control end of the sixth switch circuit can reach the second compensation voltage, thereby completing the threshold voltage compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the implementation methods in the embodiments of the present application or the related technologies, the following is a brief introduction to the drawings required for use in the embodiments or the related technology descriptions. Obviously, the drawings described below are some embodiments of the present application, and a person skilled in the art can also obtain other drawings based on these drawings.

[0061] Figure 1 A schematic diagram of the structure of the display device provided in this application;

[0062] Figure 2 Schematic diagram of the structure of the pixel circuit provided in this application Figure 1 ;

[0063] Figure 3 The timing of the control signal provided for this application Figure 1 ;

[0064] Figure 4 A schematic diagram of a pixel circuit in a first reset phase provided by the present application;

[0065] Figure 5 A schematic diagram of a pixel circuit in a first compensation stage provided by the present application;

[0066] Figure 6 A schematic diagram of a pixel circuit in the first driving voltage writing phase provided by the present application;

[0067] Figure 7 A schematic diagram of a pixel circuit in a second reset phase provided by the present application;

[0068] Figure 8 A schematic diagram of a pixel circuit in the second compensation stage provided by the present application;

[0069] Fig. 9 A schematic diagram of a pixel circuit in the second driving voltage writing phase provided by the present application;

[0070] Fig.10 Schematic diagram of the pixel circuit in the light-emitting stage provided by this application Figure 1 ;

[0071] Fig.11 Schematic diagram of the pixel circuit in the light-emitting stage provided by this application Figure 2 ;

[0072] Fig.12 Schematic diagram of the structure of the pixel circuit provided in this application Figure 2 ;

[0073] Fig.13 The timing of the control signal provided for this application Figure 2 . DETAILED DESCRIPTION

[0074] In order to make the purpose, implementation mode and advantages of the present application clearer, the exemplary implementation mode of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0075] Based on the exemplary embodiments described in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the claims attached to this application. In addition, although the disclosure in this application is introduced according to one or several exemplary examples, it should be understood that each aspect of the disclosure can also constitute a complete implementation method separately.

[0076] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their common and usual meanings.

[0077] The terms "first", "second", "third", etc. in the specification and claims of this application and the above drawings are used to distinguish similar or similar objects or entities, and do not necessarily mean to limit a specific order or sequence, unless otherwise indicated. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, for example, they can be implemented in an order other than those given in the diagrams or descriptions of the embodiments of this application.

[0078] In addition, the terms "including" and "having" and any variations thereof are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to those components expressly listed but may include other components not expressly listed or inherent to such products or devices.

[0079] With the development of technology and people's higher requirements for display devices, display panels based on micro-light emitting diodes (Micro-LED, also known as μLED) have the characteristics of being thin, light, power-saving, and self-luminous, and have attracted people's attention. Compared with active matrix organic light emitting diodes (AMOLED), micro-LEDs have the advantages of smaller size, faster response speed, higher luminous efficiency, stronger stability, and longer service life.

[0080] For example, Figure 1A schematic diagram of the structure of the display device provided in this application, such as Figure 1 As shown, the display device includes a controller, a timing controller (TCON for short) board and a display panel.

[0081] The display panel includes a pixel matrix composed of multiple sub-pixels and a thin film transistor (TFT) driving circuit. Figure 1 The dotted box portion in the display panel represents the pixel matrix.

[0082] Each sub-pixel in the pixel matrix includes a pixel circuit, each pixel circuit is connected to a TFT driving circuit and a TCON board respectively, and a controller is connected to the TFT driving circuit and the TCON board respectively.

[0083] It should be noted that the TFT driving circuit may be located on the upper and lower sides of the display panel, on the left and right sides of the display panel, or on any side. The embodiment of the present application does not limit the position of the TFT driving circuit in the display panel.

[0084] After the controller obtains the image data, it outputs a control signal to the pixel circuit according to the image data through the first control signal output terminal S1, the second control signal output terminal SWEEP, the third control signal output terminal S3, the fourth control signal output terminal S4, the fifth control signal output terminal S5, the sixth control signal output terminal S6, and the switch signal output terminal EM in the TFT driving circuit.

[0085] The control signal and the reset signal are output to the pixel circuit through the pulse width modulation (PWM) driving signal output terminal Date_PWM, the pulse amplitude modulation (PAM) driving signal output terminal Date_PAM and the reset signal output terminal REF in the TCON board.

[0086] The pixel circuit controls the light emission and extinguishing of the micro light emitting diode in the pixel circuit according to the control signal and the reset signal.

[0087] In the prior art, the driving method of the pixel circuit is usually a combination of PWM driving and PAM driving. The control signal output by the PWM driving signal output terminal Date_PWM can control the light-emitting duration of the micro-LED, thereby controlling the brightness perceived by the human eye. The control signal output by the PAM driving signal output terminal Date_PAM can control the light-emitting wavelength of the micro-LED.

[0088] However, the pixel circuit includes TFTs for implementing PWM drive and PAM drive. After long-term use, the threshold voltage of TFTs is prone to drift, resulting in changes in the light emission time and wavelength of the micro-LEDs, resulting in poor display effects.

[0089] In view of the problems existing in the prior art, the inventors found in the process of studying pixel circuits that in order to eliminate the influence of threshold voltage drift, a compensation circuit can be added to the pixel circuit, and a compensation voltage can be applied to the control end of the TFT in the PWM drive circuit and the PAM drive circuit through the compensation circuit, so that on the basis of the compensation voltage, by applying an additional voltage, the TFT can be turned on and off without being affected by the threshold voltage drift. As a result, the current flowing through the micro-light-emitting diode is more stable, and the light-emitting duration and wavelength of the micro-light-emitting diode will not change, thereby improving the display effect. Based on the above inventive concept, the pixel circuit in this application is designed.

[0090] The circuit structure of the pixel circuit provided in the present application is described below.

[0091] Figure 2 Schematic diagram of the structure of the pixel circuit provided in this application Figure 1 ,like Figure 2 As shown, the pixel circuit includes a PWM driving circuit 11, a first compensation circuit 12, a PAM driving circuit 13, a second compensation circuit 14, a reset circuit 15, and a light emitting circuit 16.

[0092] Figure 2 An example is given of a case where each of the switch circuits included in the pixel circuit is a P-type TFT, but in some cases, at least one of the switch circuits included in the pixel circuit may be an N-type TFT.

[0093] The PWM driving circuit 11 includes a first switch circuit T1 , a first capacitor C1 , a second capacitor C2 , and a second switch circuit T2 .

[0094] The first end of the first switch circuit T1 is connected to the PWM drive signal output terminal Date_PWM, the second end of the first switch circuit T1 is respectively connected to the first end of the first capacitor C1 and the first end of the second capacitor C2, the control end of the first switch circuit T1 is connected to the first control signal output terminal S1, the second end of the second capacitor C2 is connected to the second control signal output terminal SWEEP, the second end of the first capacitor C1 is connected to the control end 17 of the second switch circuit T2, the first end of the second switch circuit T2 is connected to the first power supply terminal, and the first power supply terminal is the reference power supply output terminal VDD; the control end 17 of the second switch circuit T2 is the control end 17 of the PWM drive circuit 11.

[0095] The first switch circuit T1 is controlled by a control signal outputted from the first control signal output terminal S1, that is, the S1 signal. When the S1 signal is at a first level, the first switch circuit T1 is in an on state; when the S1 signal is at a second level, the first switch circuit T1 is in an off state.

[0096] It should be noted that, when the switch circuit is a P-type TFT, the first level is a low level and the second level is a high level.

[0097] The first switch circuit T1 is used to set the voltage of the control terminal 17 of the second switch circuit T2 to the first driving voltage, so as to achieve driving voltage writing.

[0098] The second switch circuit T2 is controlled by the voltage at its control end. When the switch circuit is a P-type TFT, when the voltage at the control end is less than the first compensation voltage, the second switch circuit T2 is in an on state; when the voltage at the control end is greater than or equal to the first compensation voltage, the second switch circuit T2 is in an off state.

[0099] The second switch circuit T2 is used to control the disconnection of the sixth switch circuit T6.

[0100] The reset circuit 15 is connected to the control end of the second switch circuit T2 through the first compensation circuit 12, and the second end of the second switch circuit T2 is connected to the first compensation circuit 12;

[0101] The control terminal 18 of the PAM driving circuit 13 is connected to the reset circuit 15 , the second compensation circuit 14 , and the second end of the second switch circuit T2 respectively, and the light emitting circuit 16 is connected to the PAM driving circuit 13 .

[0102] The first compensation circuit 12 includes a third switch circuit T3 , and the reset circuit 15 includes a fourth switch circuit T4 .

[0103] A first end of the third switch circuit T3 is connected to the control end of the second switch circuit T2, a second end of the third switch circuit T3 is connected to the second end of the second switch circuit T2, and a control end of the third switch circuit T3 is connected to the third control signal output end S3.

[0104] The control end of the fourth switch circuit T4 is connected to the fourth control signal output end S4, the first end of the fourth switch circuit T4 is connected to the second end of the third switch circuit T3, and the second end of the fourth switch circuit T4 is connected to the reset signal output end REF.

[0105] The third switch circuit T3 is controlled by a control signal outputted from the third control signal output terminal S3, that is, the S3 signal. When the S3 signal is at a first level, the third switch circuit T3 is in an on state; when the S3 signal is at a second level, the third switch circuit T3 is in an off state.

[0106] The third switch circuit T3 is used to set the voltage of the control terminal 17 of the second switch circuit T2 to the first compensation voltage to achieve threshold voltage compensation.

[0107] The fourth switch circuit T4 is controlled by a control signal outputted from the fourth control signal output terminal S4, that is, the S4 signal. When the S4 signal is at a first level, the fourth switch circuit T4 is in an on state; when the S4 signal is at a second level, the fourth switch circuit T4 is in an off state.

[0108] The fourth switch circuit T4 is used to set the voltage of the control terminal 17 of the second switch circuit T2 and the voltage of the control terminal 18 of the sixth switch circuit T6 to a reset voltage.

[0109] The PAM driving circuit 13 includes a fifth switch circuit T5, a third capacitor C3, a fourth capacitor C4, and a sixth switch circuit T6.

[0110] A first end of the fifth switch circuit T5 is connected to a first end of the fourth capacitor C4, a second end of the fifth switch circuit T5 is connected to the PAM drive signal output terminal Date_PAM, and a control end of the fifth switch circuit T5 is connected to the fifth control signal output terminal S5.

[0111] The second end of the fourth capacitor C4 is respectively connected to the first end of the third capacitor C3 and the control end 18 of the sixth switch circuit T6, the first power supply end is the reference power supply output end VDD, and the reference power supply output end VDD is respectively connected to the second end of the third capacitor C3 and the first end of the sixth switch circuit T6; the control end 18 of the sixth switch circuit T6 is the control end 18 of the PAM drive circuit 13.

[0112] A first terminal of the fourth switch circuit T4 is connected to a control terminal 18 of the sixth switch circuit T6 .

[0113] The fifth switch circuit T5 is controlled by a control signal outputted from the fifth control signal output terminal S5, that is, the S5 signal. When the S5 signal is at a first level, the fifth switch circuit T5 is in an on state; when the S5 signal is at a second level, the fifth switch circuit T5 is in an off state.

[0114] The fifth switch circuit T5 is used to set the voltage of the control terminal 18 of the sixth switch circuit T6 to the second driving voltage, so as to realize the writing of the driving voltage.

[0115] The sixth switch circuit T6 is controlled by the voltage at its control end. When the switch circuit is a P-type TFT, when the voltage at the control end is less than the second compensation voltage, the sixth switch circuit T6 is in an on state; when the voltage at the control end is greater than or equal to the second compensation voltage, the sixth switch circuit T6 is in an off state.

[0116] The sixth switch circuit T6 is used to control the light emission and extinguishing of the micro light emitting diode Micro-LED.

[0117] The second compensation circuit 14 includes a seventh switch circuit T7.

[0118] A first end of the seventh switch circuit T7 is connected to the control end 18 of the sixth switch circuit T6 , a second end of the seventh switch circuit T7 is connected to the second end of the sixth switch circuit T6 , and a control end of the seventh switch circuit T7 is connected to the sixth control signal output end S6 .

[0119] The seventh switch circuit T7 is controlled by the control signal output by the sixth control signal output terminal S6, that is, the S6 signal. When the S6 signal is at the first level, the seventh switch circuit T7 is in the on state; when the S6 signal is at the second level, the seventh switch circuit T7 is in the off state.

[0120] The seventh switch circuit T7 is used to set the voltage of the control terminal 18 of the sixth switch circuit T6 to the second compensation voltage to achieve threshold voltage compensation.

[0121] The lighting circuit 16 includes an eighth switch circuit T8 and a micro light emitting diode Micro-LED.

[0122] The control end of the eighth switch circuit T8 is connected to the switch signal output end EM, the first end of the eighth switch circuit T8 is connected to the second end of the sixth switch circuit T6, the second end of the eighth switch circuit T8 is connected to the first end of the micro light emitting diode Micro-LED, and the second end of the micro light emitting diode Micro-LED is connected to the second power supply end. The first end is a positive electrode, the second end is a negative electrode, and the second power supply end is a ground end VSS.

[0123] The second end of the second switch circuit T2 is connected to the control end 18 of the sixth switch circuit T6.

[0124] The eighth switch circuit T8 is controlled by a control signal outputted from the switch signal output terminal EM, namely, the EM signal. When the EM signal is at a first level, the eighth switch circuit T8 is in an on state; when the EM signal is at a second level, the eighth switch circuit T8 is in an off state.

[0125] The eighth switch circuit T8 is used to control the light emission and extinguishing of the micro light emitting diode Micro-LED.

[0126] For example, Figure 3 The timing of the control signal provided for this application Figure 1 , the control signal timing diagram is used to control Figure 2 The operation process of the pixel circuit is described below.

[0127] like Figure 3 As shown, a display cycle T includes, arranged in time from early to late, a first reset stage t1, a first compensation stage t2, a first drive voltage writing stage t3, a second reset stage t4, a second compensation stage t5, a second drive voltage writing stage t6, and a light-emitting stage t7.

[0128] The control signal output by the second control signal output terminal SWEEP is a SWEEP signal, the control signal output by the PWM drive signal output terminal Date_PWM is a Date_PWM signal, and the control signal output by the PAM drive signal output terminal Date_PAM is a Date_PAM signal.

[0129] In the first reset phase t1, the S3 signal, S4 signal, and Date_PWM signal are low level signals, the S1 signal, S5 signal, S6 signal, EM signal, and Date_PAM signal are high level signals, and the SWEEP signal remains at a low level for a preset period of time and then turns to a high level.

[0130] For example, in Figure 2 On the basis of Figure 4 The schematic diagram of the pixel circuit in the first reset phase provided by the present application is as follows: Figure 4 As shown in the figure, a switch unit with a cross indicates disconnection, and an uncrossed switch unit indicates conduction.

[0131] Because the S3 signal and the S4 signal are low level signals, the third switch circuit T3 and the fourth switch circuit T4 are turned on; the S1 signal, the S5 signal, the S6 signal, and the EM signal are high level signals, so the first switch circuit T1, the fifth switch circuit T5, the seventh switch circuit T7, and the eighth switch circuit T8 are turned off.

[0132] The reset signal output terminal REF outputs a reset signal of a reset voltage. The reset signal passes through the fourth switch circuit T4 and the third switch circuit T3 in sequence, and reaches the control terminal 17 of the second switch circuit T2 and the second end of the first capacitor C1, so that the voltage of the control terminal 17 of the second switch circuit T2 is the reset voltage, and the first capacitor C1 is charged.

[0133] Since the reset voltage is a negative voltage, the second switch circuit T2 is turned on.

[0134] The reset signal reaches the control terminal 18 of the sixth switch circuit T6, so that the voltage of the control terminal 18 of the sixth switch circuit T6 is the reset voltage, and the sixth switch circuit T6 is also turned on.

[0135] Since the SWEEP signal remains at a low level for a preset time and then changes to a high level, the SWEEP signal is coupled through the second capacitor C2, so that after the voltage of the control terminal 17 of the second switch circuit T2 changes, the changed voltage remains unchanged.

[0136] In the first compensation stage t2, the S3 signal and the Date_PWM signal are low level signals, and the S1 signal, the S4 signal, the S5 signal, the S6 signal, the EM signal, the Date_PAM signal, and the SWEEP signal are high level signals.

[0137] For example, in Figure 2 On the basis of Figure 5 The pixel circuit schematic diagram in the first compensation stage provided by the present application is as follows: Figure 5 As shown in the figure, a switch unit with a cross indicates disconnection, and an uncrossed switch unit indicates conduction.

[0138] Because the S3 signal is a low level signal, the third switch circuit T3 is turned on; the S1 signal, S4 signal, S5 signal, S6 signal, and EM signal are high level signals, so the first switch circuit T1, the fourth switch circuit T4, the fifth switch circuit T5, the seventh switch circuit T7, and the eighth switch circuit T8 are turned off.

[0139] Because the second switch circuit T2 is turned on in the first reset phase, at the beginning of the first compensation phase, the reference power supply output terminal VDD applies a voltage to the control terminal 17 of the second switch circuit T2 through the second switch circuit T2 and the third switch circuit T3.

[0140] When the voltage at the control terminal 17 of the second switch circuit T2 reaches the first compensation voltage, the second switch circuit T2 is disconnected.

[0141] It should be noted that the first compensation voltage is a critical voltage for the second switch circuit T2 to be turned on and off. A1 =V VDD +V th1 , where V VDD Indicates the voltage output from the reference power supply output terminal VDD, V th1 represents the threshold voltage of the second switch circuit T2, V th1 is a negative voltage.

[0142] It should be noted that the second control signal output terminal SWEEP outputs a control signal of a second level to ensure that the voltage at the T2 control terminal 17 of the second switch circuit remains unchanged after reaching the first compensation voltage.

[0143] At the beginning of the first compensation phase, the reference power supply output terminal VDD applies a voltage to the control terminal 18 of the sixth switch circuit T6 through the second switch circuit T2, and the voltage of the control terminal 18 of the sixth switch circuit T6 gradually increases.

[0144] When the first compensation voltage is greater than or equal to the second compensation voltage, since the voltage at the control terminal 17 of the second switch circuit T2 reaches the first compensation voltage, the second switch circuit T2 is disconnected. At this time, the voltage at the control terminal 18 of the sixth switch circuit T6 also reaches the first compensation voltage, and the sixth switch circuit T6 is disconnected.

[0145] When the first compensation voltage is less than the second compensation voltage, since the voltage at the control terminal 17 of the second switch circuit T2 reaches the first compensation voltage, the second switch circuit T2 is disconnected. At this time, the voltage at the control terminal 18 of the sixth switch circuit T6 also reaches the first compensation voltage, the voltage no longer increases, and the sixth switch circuit T6 is turned on.

[0146] The embodiment of the present application does not limit the state of the sixth switch circuit T6 in the first reset phase.

[0147] In the first driving voltage writing phase t3, the S1 signal is a low level signal, the S3 signal, S4 signal, S5 signal, S6 signal, EM signal, Date_PAM signal, and SWEEP signal are high level signals, and the Date_PWM signal remains a low level signal for a preset period of time and then turns to a high level.

[0148] For example, in Figure 2 On the basis of Figure 6 The schematic diagram of the pixel circuit in the first driving voltage writing stage provided by the present application is as follows: Figure 6 As shown in the figure, a switch unit with a cross indicates disconnection, and an uncrossed switch unit indicates conduction.

[0149] Because the S1 signal is a low level signal, the first switch circuit T1 is turned on; the S3 signal, S4 signal, S5 signal, S6 signal, and EM signal are high level signals, so the third switch circuit T3, the fourth switch circuit T4, the fifth switch circuit T5, the seventh switch circuit T7, and the eighth switch circuit T8 are turned off.

[0150] The PWM driving signal output terminal Date_PWM applies a voltage to the control terminal 17 of the second switching circuit T2 through the first switching circuit T1 and the first capacitor C1 to reach the first driving voltage.

[0151] The Date_PWM signal remains at a low level for a preset period of time and then turns to a high level, ensuring that after the second switch circuit T2 is disconnected, the voltage of the control signal is coupled through the first capacitor C1 to reach the control terminal 17 of the second switch circuit T2, so that the voltage of the control terminal 17 is the first driving voltage.

[0152] Since the first driving voltage is greater than the first compensation voltage, the second switch circuit T2 remains in an off state.

[0153] It should be noted that the first driving voltage V A2=V VDD +V th1 +V Date_PWM , where V VDD Indicates the voltage output from the reference power supply output terminal VDD, V th1 represents the threshold voltage of the second switch circuit T2, V th1 is a negative voltage, V Date_PWM Represents the voltage of the Date_PWM signal, V Date_PWM is a positive voltage.

[0154] It should be noted that the second control signal output terminal SWEEP outputs a control signal of a second level to ensure that after the voltage of the T2 control terminal 17 of the second switch circuit reaches the first driving voltage, the voltage remains unchanged.

[0155] In the second reset phase t4 , the S4 signal and the Date_PWM signal are low level signals, and the S1 signal, the S3 signal, the S5 signal, the S6 signal, the EM signal, the Date_PAM signal, and the SWEEP signal are high level signals.

[0156] For example, in Figure 2 On the basis of Figure 7 The pixel circuit schematic diagram provided by the present application in the second reset phase is as follows: Figure 7 As shown in the figure, a switch unit with a cross indicates disconnection, and an uncrossed switch unit indicates conduction.

[0157] Because the S4 signal is a low level signal, the fourth switch circuit T4 is turned on; the S1 signal, S3 signal, S5 signal, S6 signal, and EM signal are high level signals, so the first switch circuit T1, the third switch circuit T3, the fifth switch circuit T5, the seventh switch circuit T7, and the eighth switch circuit T8 are disconnected.

[0158] The reset signal output terminal REF outputs a reset signal of a reset voltage. The reset signal passes through the fourth switch circuit T4 to reach the control terminal 18 of the sixth switch circuit T6, the first end of the third capacitor C3, and the second end of the fourth capacitor C4, so that the voltage of the control terminal 18 of the sixth switch circuit T6 is the reset voltage, and the third capacitor C3 and the fourth capacitor C4 are charged.

[0159] Since the reset voltage is a negative voltage, the sixth switch circuit T6 is turned on.

[0160] Since the second control signal output terminal SWEEP outputs a control signal of the second level, it is ensured that after the voltage of the T2 control terminal 17 of the second switch circuit reaches the first driving voltage, the voltage remains unchanged.

[0161] In the second compensation stage t5 , the S6 signal and the Date_PWM signal are low level signals, and the S1 signal, the S3 signal, the S4 signal, the S5 signal, the EM signal, the Date_PAM signal, and the SWEEP signal are high level signals.

[0162] For example, in Figure 2 On the basis of Figure 8 The pixel circuit schematic diagram in the second compensation stage provided by the present application is as follows: Figure 8 As shown in the figure, a switch unit with a cross indicates disconnection, and an uncrossed switch unit indicates conduction.

[0163] Because the S6 signal is a low level signal, the seventh switch circuit T7 is turned on; the S1 signal, S3 signal, S4 signal, S5 signal, and EM signal are high level signals, so the first switch circuit T1, the third switch circuit T3, the fourth switch circuit T4, the fifth switch circuit T5, and the eighth switch circuit T8 are disconnected.

[0164] Because the sixth switch circuit T6 is turned on in the second reset phase, at the beginning of the second compensation phase, the reference power supply output terminal VDD applies a voltage to the control terminal 18 of the sixth switch circuit T6 through the sixth switch circuit T6 and the seventh switch circuit T7.

[0165] When the voltage at the control terminal 18 of the sixth switch circuit T6 reaches the second compensation voltage, the sixth switch circuit T6 is disconnected.

[0166] It should be noted that the second compensation voltage is a critical voltage for the sixth switch circuit T6 to be turned on and off. B1 =V VDD +V th2 , where V VDD Indicates the voltage output from the reference power supply output terminal VDD, V th2 represents the threshold voltage of the sixth switch circuit T6, V th2 is a negative voltage.

[0167] It should be noted that the second control signal output terminal SWEEP outputs a control signal of a second level to ensure that the voltage at the T2 control terminal 17 of the second switch circuit remains unchanged after reaching the first compensation voltage.

[0168] In the second driving voltage writing phase t6, the S5 signal and the Date_PWM signal are low level signals, the S1 signal, the S3 signal, the S4 signal, the S6 signal, the EM signal, and the SWEEP signal are high level signals, and the Date_PAM signal remains at a high level for a preset period of time and then turns to a low level.

[0169] For example, in Figure 2 On the basis of Fig. 9The schematic diagram of the pixel circuit in the second driving voltage writing phase provided by the present application is as follows: Fig. 9 As shown in the figure, a switch unit with a cross indicates disconnection, and an uncrossed switch unit indicates conduction.

[0170] Because the S5 signal is a low level signal, the fifth switch circuit T5 is turned on; the S1 signal, S3 signal, S4 signal, S6 signal, and EM signal are high level signals, so the first switch circuit T1, the third switch circuit T3, the fourth switch circuit T4, the seventh switch circuit T7, and the eighth switch circuit T8 are turned off.

[0171] The PAM driving signal output terminal Date_PAM applies a voltage to the control terminal 18 of the sixth switching circuit T6 through the fifth switching circuit T5 and the fourth capacitor C4 to the second driving voltage.

[0172] The Date_PAM signal remains at a high level for a preset period of time and then turns to a low level, ensuring that after the sixth switch circuit T6 is disconnected, the voltage of the control signal reaches the control terminal 18 of the sixth switch circuit T6 after coupling through the fourth capacitor C4, so that the voltage of the control terminal 18 is the second driving voltage.

[0173] Because the second driving voltage is lower than the second compensation voltage, the sixth switch circuit T6 is turned on.

[0174] It should be noted that the second driving voltage Among them, V VDD Indicates the voltage output from the reference power supply output terminal VDD, V th2 represents the threshold voltage of the sixth switch circuit T6, V th2 is a negative voltage; V Date_PAM Represents the voltage of the Date_PAM signal, V Date_PAM is a negative voltage; C′3 represents the capacitance value of capacitor C3, and C′4 represents the capacitance value of capacitor C4.

[0175] It should be noted that the second control signal output terminal SWEEP outputs a control signal of a second level to ensure that after the voltage of the T2 control terminal 17 of the second switch circuit reaches the first driving voltage, the voltage remains unchanged.

[0176] In the light-emitting stage t7, the EM signal and the Date_PWM signal are low-level signals, the S1 signal, the S3 signal, the S4 signal, the S5 signal, the S6 signal, and the Date_PAM signal are high-level signals, and the level of the SWEEP signal gradually changes from a high level to a low level.

[0177] For example, in Figure 2 On the basis of Fig.10 Schematic diagram of the pixel circuit in the light-emitting stage provided by this application Figure 1 ,like Fig.10 As shown in the figure, a switch unit with a cross indicates disconnection, and an uncrossed switch unit indicates conduction.

[0178] Because the EM signal is a low level signal, the eighth switch circuit T8 is turned on; the S1 signal, S3 signal, S4 signal, S5 signal, and S6 signal are high level signals, so the first switch circuit T1, the third switch circuit T3, the fourth switch circuit T4, the fifth switch circuit T5, and the seventh switch circuit T7 are disconnected.

[0179] The output current of the reference power supply output terminal VDD passes through the sixth switch circuit T6 and the eighth switch circuit T8 in sequence, and reaches the micro light emitting diode μLED, driving the micro light emitting diode Micro-LED to emit light.

[0180] exist Figure 2 On the basis of Fig.11 Schematic diagram of the pixel circuit in the light-emitting stage provided by this application Figure 2 ,like Fig.11 As shown in the figure, a switch unit with a cross indicates disconnection, and an uncrossed switch unit indicates conduction.

[0181] Because the level of the SWEEP signal gradually changes from a high level to a low level, the voltage of the control terminal 17 of the second switch circuit T2 gradually changes to the first driving voltage, and the second switch circuit T2 is turned on.

[0182] The reference power supply output terminal VDD applies a voltage up to the second compensation voltage to the control terminal 18 of the sixth switch circuit T6 through the second switch circuit T2 , and charges the third capacitor C3 and the fourth capacitor C4 .

[0183] The voltage at the control end 18 of the sixth switch circuit T6 is the second compensation voltage, the sixth switch circuit T6 is disconnected, and the micro light emitting diode Micro-LED stops emitting light.

[0184] The pixel circuit provided in this embodiment is connected to the control end of the second switch circuit through the first end of the third switch circuit, and the second end of the third switch circuit is connected to the second end of the second switch circuit. In the first compensation stage, the voltage of the control end of the second switch circuit reaches the first compensation voltage through the third switch circuit, and the threshold voltage compensation is completed. The first end of the seventh switch circuit is connected to the control end of the sixth switch circuit, and the second end of the seventh switch circuit is connected to the second end of the sixth switch circuit. In the second compensation stage, the voltage of the control end of the sixth switch circuit reaches the second compensation voltage through the seventh switch circuit, and the threshold voltage compensation is completed. The threshold voltage compensation of the PWM drive circuit is performed through the third switch circuit, and the threshold voltage compensation of the PAM drive circuit is performed through the seventh switch circuit, which can solve the threshold voltage drift problem of the TFT in the PWM drive circuit and the PAM drive circuit, so that the current flowing through the micro light emitting diode is more stable, and the light emission time and light emission wavelength of the micro light emitting diode will not change, thereby improving the display effect.

[0185] In the above embodiments, the switch circuits are all P-type TFTs. In some cases, at least one of the switch circuits included in the pixel circuit may be an N-type TFT. The following describes the case where the switch circuit included in the pixel circuit is an N-type TFT.

[0186] For example, in Figure 2 On the basis of Fig.12 Schematic diagram of the structure of the pixel circuit provided in this application Figure 2 ,like Fig.12 As shown, the switching circuit in the figure is an N-type TFT.

[0187] In the figure, the first power supply terminal is the ground terminal VSS, and the second power supply terminal is the reference power supply output terminal VDD; the first end of the micro light emitting diode Micro-LED is the cathode, and the second end is the anode; the first level is the high level, and the second level is the low level.

[0188] For example, Fig.13 The timing of the control signal provided for this application Figure 2 , the control signal timing diagram is used to control Fig.12 The pixel circuit shown.

[0189] In the first reset phase t1, the S3 signal, S4 signal, and Date_PWM signal are high level signals, the S1 signal, S5 signal, S6 signal, EM signal, and Date_PAM signal are low level signals, and the SWEEP signal remains high level for a preset period of time and then turns to low level.

[0190] In the first compensation stage t2, the S3 signal and the Date_PWM signal are high-level signals, and the S1 signal, the S4 signal, the S5 signal, the S6 signal, the EM signal, the Date_PAM signal, and the SWEEP signal are low-level signals.

[0191] The reference power supply output terminal VDD applies a voltage to the control terminal 17 of the second switch circuit T2 through the second switch circuit T2 and the third switch circuit T3, so that the voltage of the control terminal 17 of the second switch circuit T2 reaches the first compensation voltage.

[0192] In the first driving voltage writing phase t3, the S1 signal is a high level signal, the S3 signal, S4 signal, S5 signal, S6 signal, EM signal, Date_PAM signal, and SWEEP signal are low level signals, and the Date_PWM signal remains a high level signal for a preset period of time and then turns to a low level.

[0193] In the second reset phase t4 , the S4 signal and the Date_PWM signal are high level signals, and the S1 signal, the S3 signal, the S5 signal, the S6 signal, the EM signal, the Date_PAM signal, and the SWEEP signal are low level signals.

[0194] In the second compensation stage t5, the S6 signal and the Date_PWM signal are high-level signals, and the S1 signal, the S3 signal, the S4 signal, the S5 signal, the EM signal, the Date_PAM signal, and the SWEEP signal are low-level signals.

[0195] The reference power supply output terminal VDD applies a voltage to the control terminal 18 of the sixth switch circuit T6 through the sixth switch circuit T6 and the seventh switch circuit T7, so that the voltage of the control terminal 18 of the sixth switch circuit T6 reaches the second compensation voltage.

[0196] In the second driving voltage writing phase t6, the S5 signal and the Date_PWM signal are high level signals, the S1 signal, the S3 signal, the S4 signal, the S6 signal, the EM signal, and the SWEEP signal are low level signals, and the Date_PAM signal remains at a low level for a preset period of time and then turns to a high level.

[0197] In the light-emitting stage t7, the EM signal and the Date_PWM signal are high-level signals, the S1 signal, the S3 signal, the S4 signal, the S5 signal, the S6 signal, and the Date_PAM signal are low-level signals, and the level of the SWEEP signal gradually changes from a low level to a high level.

[0198] It should be noted that the implementation process and technical effects in each stage can be found in the above-mentioned embodiments, and this application will not repeat them.

[0199] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0200] For the convenience of explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are to better explain the principles and practical applications, so that those skilled in the art can better use the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. A pixel circuit, characterized in that: include: Pulse width modulation PWM driving circuit, first compensation circuit, pulse amplitude modulation PAM driving circuit, second compensation circuit, reset circuit, light emitting circuit; The PWM driving circuit includes a first switch circuit, a first capacitor, a second capacitor, and a second switch circuit; The first end of the first switch circuit is connected to the PWM drive signal output end, the second end of the first switch circuit is connected to the first end of the first capacitor and the first end of the second capacitor respectively, and the control end of the first switch circuit is connected to the first control signal output end; The second end of the second capacitor is connected to the second control signal output end, the second end of the first capacitor is connected to the control end of the second switch circuit, and the first end of the second switch circuit is connected to the first power supply end; The reset circuit is connected to the control end of the second switch circuit through the first compensation circuit, and the second end of the second switch circuit is connected to the first compensation circuit; The control end of the PAM driving circuit is connected to the reset circuit, the second compensation circuit, and the second end of the second switch circuit respectively, and the light emitting circuit is connected to the PAM driving circuit.

2. The pixel circuit according to claim 1, characterized in that: The first compensation circuit includes a third switch circuit, and the reset circuit includes a fourth switch circuit; The first end of the third switch circuit is connected to the control end of the second switch circuit, the second end of the third switch circuit is connected to the second end of the second switch circuit, and the control end of the third switch circuit is connected to the third control signal output end; The control end of the fourth switch circuit is connected to the fourth control signal output end, the first end of the fourth switch circuit is connected to the second end of the third switch circuit, and the second end of the fourth switch circuit is connected to the reset signal output end.

3. The pixel circuit according to claim 2, characterized in that: The PAM driving circuit includes a fifth switch circuit, a third capacitor, a fourth capacitor, and a sixth switch circuit; The second compensation circuit includes a seventh switch circuit; The light emitting circuit includes an eighth switch circuit and a micro light emitting diode; The first end of the fifth switch circuit is connected to the first end of the fourth capacitor, the second end of the fifth switch circuit is connected to the PAM drive signal output end, and the control end of the fifth switch circuit is connected to the fifth control signal output end; The second end of the fourth capacitor is respectively connected to the first end of the third capacitor and the control end of the sixth switch circuit, and the first power supply end is respectively connected to the second end of the third capacitor and the first end of the sixth switch circuit; The first end of the fourth switch circuit is connected to the control end of the sixth switch circuit; The first end of the seventh switch circuit is connected to the control end of the sixth switch circuit, the second end of the seventh switch circuit is connected to the second end of the sixth switch circuit, and the control end of the seventh switch circuit is connected to the sixth control signal output end; The control end of the eighth switch circuit is connected to the switch signal output end, the first end of the eighth switch circuit is connected to the second end of the sixth switch circuit, and the second end of the eighth switch circuit is connected to the first end of the micro light emitting diode; The second end of the micro light emitting diode is connected to the second power supply end.

4. The pixel circuit according to claim 3, characterized in that: In the first reset stage, the third control signal output terminal outputs a control signal of a first level to turn on the third switch circuit; The fourth control signal output terminal outputs a control signal of a first level to turn on the fourth switch circuit; The control signal outputted by the second control signal output terminal maintains the first level for a preset period of time and then changes to the second level; The reset signal output terminal outputs a reset signal of a reset voltage, and the reset signal passes through the fourth switch circuit and the third switch circuit in sequence to reach the control terminal of the second switch circuit, so that the voltage of the control terminal of the second switch circuit is the reset voltage and the second switch circuit is turned on.

5. The pixel circuit according to claim 4, characterized in that: In a first compensation phase after the first reset phase, the third control signal output terminal outputs a control signal of a first level to turn on the third switch circuit; The first power supply end applies a voltage to the control end of the second switch circuit through the second switch circuit and the third switch circuit. When the voltage at the control end of the second switch circuit reaches the first compensation voltage, the second switch circuit is disconnected.

6. The pixel circuit according to claim 5, characterized in that: In a first driving voltage writing phase after the first compensation phase, the first control signal output terminal outputs a control signal of a first level to turn on the first switch circuit; The control signal outputted by the PWM drive signal output terminal is maintained at the first level for a preset period of time and then changes to the second level; The PWM driving signal output terminal applies a voltage to the first driving voltage to the control terminal of the second switching circuit through the first switching circuit and the first capacitor; In a second resetting phase after the first driving voltage writing phase, the fourth control signal output terminal outputs a control signal of a first level to turn on the fourth switch circuit; The reset signal output terminal outputs a reset signal of the reset voltage; The reset signal sequentially passes through the fourth switch circuit to reach the control end of the sixth switch circuit, so that the voltage of the control end of the sixth switch circuit is the reset voltage and the sixth switch circuit is turned on.

7. The pixel circuit according to claim 6, characterized in that: In a second compensation phase after the second reset phase, the sixth control signal output terminal outputs a control signal of a first level to turn on the seventh switch circuit; The first power supply end applies a voltage to the control end of the sixth switch circuit through the sixth switch circuit and the seventh switch circuit. When the voltage of the control end of the sixth switch circuit reaches the second compensation voltage, the sixth switch circuit is disconnected.

8. The pixel circuit according to claim 7, characterized in that: In a second driving voltage writing phase after the second compensation phase, the fifth control signal output terminal outputs a control signal of a first level to turn on the fifth switch circuit; The control signal output by the PAM drive signal output terminal is to maintain the second level for a preset time and then turn to the first level, and the PAM drive signal output terminal applies a voltage to the control terminal of the sixth switch circuit through the fifth switch circuit and the fourth capacitor to the second drive voltage, and the sixth switch circuit is turned on; In the light emitting stage after the second driving voltage writing stage, the switch signal output terminal outputs a control signal of a first level to turn on the eighth switch circuit; The first power supply end or the second power supply end outputs a current which passes through the micro light emitting diode to drive the micro light emitting diode to emit light; The level of the control signal output by the second control signal output terminal gradually changes from the second level to the first level, so that the voltage of the control terminal of the second switch circuit gradually changes to the first driving voltage, and the second switch circuit is turned on; The first power supply end applies a voltage to the control end of the sixth switch circuit through the second switch circuit, up to the second compensation voltage, the sixth switch circuit is disconnected, and the micro light emitting diode stops emitting light.

9. The pixel circuit according to claim 3, characterized in that: The third control signal output terminal outputs a control signal of a first level in the first reset stage and the first compensation stage, and outputs a control signal of a second level in the first drive voltage writing stage, the second reset stage, the second compensation stage, the second drive voltage writing stage, and the light emitting stage.

10. The pixel circuit according to claim 3, characterized in that: The sixth control signal output terminal outputs a control signal of the first level in the second compensation stage, and outputs a control signal of the second level in the first reset stage, the first compensation stage, the first drive voltage writing stage, the second reset stage, the second drive voltage writing stage, and the light emitting stage.

Images