CN111583857B

CN111583857B - Pixel driving circuit, driving method thereof and display panel

Info

Publication number: CN111583857B
Application number: CN202010472598.XA
Authority: CN
Inventors: 王婷; 伍黄尧; 周洪波
Original assignee: Xiamen Tianma Microelectronics Co Ltd
Current assignee: Xiamen Tianma Microelectronics Co Ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2021-04-30
Anticipated expiration: 2040-05-29
Also published as: CN111583857A

Abstract

The invention discloses a pixel driving circuit, a driving method thereof and a display panel, wherein the pixel driving circuit comprises: the data writing module is used for responding to the current scanning signal and transmitting the data signal voltage to the oscillator module; the oscillator module is used for generating a square wave signal to the light-emitting module according to the data signal voltage transmitted by the data writing module and adjusting the proportion of the first signal holding time of the square wave signal; and the light emitting module is used for emitting light in response to the first signal of the square wave signal. The pixel driving circuit, the driving method thereof and the display panel provided by the invention can generate the square wave signal through the oscillator module, and can control the duty ratio of the square wave signal at the same time, thereby improving the luminous efficiency of the luminous module.

Description

Pixel driving circuit, driving method thereof and display panel

Technical Field

The invention relates to the technical field of display, in particular to a pixel driving circuit, a driving method thereof and a display panel.

Background

Micro Light Emitting Diode (Micro-LED) display panels are widely considered as an important development direction of future display technologies in the industry due to their characteristics of low driving voltage, long service life, and the like.

The conventional pixel Driving circuit generally adopts a 7T1C structure (7 thin film transistors and 1 capacitor), and controls the gate-source current of a Driving TFT (thin film transistor) to emit light by voltage control, and the emission luminance thereof depends on the magnitude of the gate-source current. However, when the conventional driving circuit is applied to a Micro LED display panel, the chromaticity-current curve of the LED changes greatly, and a slight change in current causes a change in chromaticity that is noticeable to the human eye. Therefore, if the Micro LED panel adopts the traditional drive circuit, the problem of chromaticity change under different gray scales is difficult to avoid.

In the implementation process, the inventor finds that at least the following problems exist in the conventional technology: the traditional driving circuit is adopted, and the current is used for controlling the brightness, so that the problem of chromaticity change under different gray scales is difficult to avoid.

Disclosure of Invention

In view of this, the present invention provides a pixel driving circuit, a driving method thereof, and a display panel, which can control the brightness of a light emitting module by setting an oscillator module to generate a square wave signal and adjusting the duty ratio of the square wave signal.

In one aspect, the present invention provides a pixel driving circuit, including:

the data writing module is used for responding to the current scanning signal and transmitting the data signal voltage to the oscillator module;

the oscillator module is used for generating a square wave signal to the light-emitting module according to the data signal voltage transmitted by the data writing module and adjusting the proportion of the first signal holding time of the square wave signal;

and the light emitting module is used for emitting light in response to the first signal of the square wave signal.

In another aspect, the present invention provides a display panel including the pixel driving circuit.

In another aspect, the present invention provides a driving method of a pixel driving circuit, the pixel driving circuit including:

the oscillator module is used for generating a square wave signal to the light-emitting module according to the data signal voltage transmitted by the data writing module and adjusting the proportion of the high potential holding time of the square wave signal;

the light emitting module is used for responding to a first signal of the square wave signal to emit light;

the driving method comprises the following steps;

in the first stage, the data writing module responds to the scanning signal and writes the data signal into the oscillator module;

and a second stage: the oscillator module responds to a data signal of the data writing module and outputs a first signal to the light-emitting module, and the light-emitting module responds to the first signal to emit light;

and a third stage: the oscillator module responds to the data signal of the data writing module and outputs a second signal to the light-emitting module, and the light-emitting module responds to the second signal and is turned off;

and in the fourth stage, the light-emitting module emits light in response to the first signal.

Compared with the prior art, the pixel driving circuit, the driving method thereof and the display panel provided by the invention at least realize the following beneficial effects:

the invention discloses a pixel driving circuit, a driving method thereof and a display panel, comprising the following steps: the data writing module is used for responding to the current scanning signal and transmitting the data signal voltage to the oscillator module; the oscillator module is used for generating a square wave signal to the light-emitting module according to the data signal voltage transmitted by the data writing module and adjusting the proportion of the first signal holding time of the square wave signal; and the light emitting module is used for emitting light in response to the first signal of the square wave signal. The square wave signal is generated through the oscillator module, the duty ratio of the square wave signal can be adjusted through the oscillator module, the square wave signal can control the light emitting condition of the light emitting module, the light emitting condition of the light emitting module can be adjusted through the adjusting and controlling oscillator module, and then the brightness of the light emitting module is controlled.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a prior art pixel driving circuit;

FIG. 2 is a graph of luminous efficiency of the Micro LED of the light emitting element of FIG. 1;

FIG. 3 is a color shift characteristic curve of the Micro LED of FIG. 1;

FIG. 4 is a pixel driving circuit according to the present invention;

fig. 5 is a flowchart of a driving method of a pixel driving circuit according to the present invention;

FIG. 6 is a timing diagram of the pixel driving circuit of FIG. 4 prior to adjustment;

FIG. 7 is a timing diagram of the pixel driver circuit of FIG. 4 after adjustment;

FIG. 8 is a diagram of yet another pixel driving circuit provided by the present invention;

FIG. 9 is a timing diagram of the pixel driving circuit of FIG. 8 before adjustment;

FIG. 10 is a timing diagram of the pixel driving circuit of FIG. 8 after adjustment;

FIG. 11 is a schematic diagram of yet another pixel driving circuit according to the present invention;

FIG. 12 is a schematic diagram of yet another pixel driving circuit provided by the present invention;

fig. 13 is a flowchart of a driving method of a pixel driving circuit according to another embodiment of the present invention;

FIG. 14 is yet another pixel driving circuit provided by the present invention;

FIG. 15 is yet another pixel driving circuit provided by the present invention;

fig. 16 is a display panel provided by the present invention.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the related art, fig. 1 is a pixel driving circuit of the related art, fig. 2 is a graph of luminous efficiency of a light emitting element Micro LED of fig. 1, and fig. 3 is a color shift characteristic curve of the light emitting element Micro LED of fig. 1; as shown in fig. 1, the pixel driving circuit shown in fig. 1 is composed of seven thin film transistors M1-M7 and a capacitor C, under the control of control signals S1, S2 and Emit, a data signal voltage Vdata is stored in the capacitor C by a data signal, and after the data signal voltage is written, the data signal voltage Vdata stored in the capacitor C is transmitted to the gate of the thin film transistor M1 to generate a current to drive the Micro LED to Emit light. However, the light emitting efficiency and the color shift characteristics of the light emitting element Micro LED are different when the light emitting element Micro LED is driven by different driving currents. As shown in fig. 2 below, the light emitting efficiency of the light emitting element Micro LED is low when the driving current is at low brightness, and with continued reference to fig. 3, due to the color shift characteristics of the light emitting element Micro LED, the wavelengths of the light emitted by the light emitting element Micro LED are different under different currents, resulting in different light emitting colors of the light emitting element Micro LED. Further, the driving current is used for adjusting the brightness of the Micro LED of the light-emitting element, and the problems of low luminous efficiency, color cast and the like are caused.

In order to solve the problems that the luminous efficiency of the light emitting module can be improved and color shift is not caused when the brightness of the light emitting module is adjusted, the inventor has conducted the following research on the display panel in the related art: the invention provides a pixel driving circuit. As for a pixel driving circuit provided by the present invention, the following will be described in detail.

Fig. 4 is a pixel driving circuit provided in the present invention, the pixel driving circuit 200 includes a data writing module 1 for transmitting a data signal voltage din to an oscillator module 2 in response to a current scan signal gin; the oscillator module 2 is used for generating a square wave signal to the light emitting module 3 according to the data signal voltage din transmitted by the data writing module 1, and meanwhile, adjusting the proportion of the first signal holding time of the square wave signal 3; and the light emitting module 3 is used for emitting light in response to a first signal of the square wave signal.

It is understood that the first signal is an enable signal that can cause the light emitting module to emit light in the square wave signal. The oscillator module 2 responds to the data signal din of the data input module 1, and can control the internal resistance of the oscillator module 2 according to the data signal din, so that the duty ratio of the square wave signal generated by the oscillator module 2 can be adjusted, the occupied time proportion of the first signal in one square wave signal is controlled to be increased, and the light emitting brightness of the light emitting module 3 is regulated.

Fig. 5 is a flowchart of a driving method of a pixel driving circuit according to the present invention, and referring to fig. 4 and fig. 5 successively, the present embodiment provides a driving method of a pixel driving circuit, which is used for the pixel driving circuit shown in fig. 4, and the driving method includes the steps of:

step 101, in the first stage, a data writing module responds to a scanning signal and writes a data signal into an oscillator module;

step 102, the second stage: the oscillator module responds to a data signal of the data writing module and outputs a first signal to the light-emitting module, and the light-emitting module responds to the first signal to emit light;

step 103, a third stage: the oscillator module responds to the data signal of the data writing module and outputs a second signal to the light-emitting module, and the light-emitting module responds to the second signal and is turned off;

and 104, in the fourth stage, the light-emitting module emits light in response to the first signal.

The first signal is an enable signal which can enable the light-emitting module to emit light in the square wave signal, the square wave signal can control the light-emitting module not to emit light in the second signal, and the first signal and the second signal are opposite signals. Meanwhile, the duty ratio of the square wave signal is improved, namely the duty ratio of the duration of the first signal in the square wave signal is improved, so that the brightness of the light-emitting unit can be adjusted, and the light-emitting efficiency is improved.

FIG. 6 is a timing diagram of the pixel driving circuit of FIG. 4 before adjustment, and FIG. 7 is a timing diagram of the pixel driving circuit of FIG. 4 after adjustment; as shown in fig. 6 and 7, in the first stage, the data writing module 1 writes the data signal din into the oscillator module 2 in response to the scanning signal gin, and in the second stage and the third stage, the oscillator module 2 oscillates to generate a square wave signal and sends the first signal to the light emitting module 3; and in the fourth stage, the light-emitting module emits light in response to the first signal. It can be understood that, when the data signal din is not adjusted, the value of the data signal din is 0V, the square wave signal generated by oscillation of the oscillator module is as shown in fig. 6, the first signal is a low-level signal, and the second signal is a high-level signal. And then adjust data signal din, rise its signal to 2V, the square wave signal that the oscillation of oscillator module produced at this moment is as shown in fig. 7, can obviously obtain the duty cycle that has increased first signal, and then can be favorable to improving luminous efficiency. In fig. 6 and 7, only the enable signal of the light emitting module is taken as a low-potential signal, and may also be taken as a high-potential signal, that is, the enable signal of the light emitting module is not limited in the present invention, and may be set according to the actual situation.

Fig. 8 is still another pixel driving circuit provided by the present invention, wherein the oscillator module in the pixel driving circuit 200 comprises a first inverter X1, a second inverter X2, a first capacitor C1, a first resistor R1 and a brightness adjusting unit 21;

a brightness adjusting unit 21 having a first terminal electrically connected to the data writing module 1, a second terminal electrically connected to the input terminal of the first inverter X1 and the first node N1, and a third terminal electrically connected to the second node N2;

a first inverter X1 having an input terminal electrically connected to the second terminal of the brightness adjusting unit 21 and an output terminal connected to the second node N2, wherein the first inverter N2 further includes a first pole connected to the first voltage signal output terminal VGH, and the output terminal further connected to the second voltage signal output terminal VGL; the first voltage signal output terminal VGH is used for providing a high-potential signal, and the second voltage signal output terminal VGL is used for providing a low-potential signal.

A second inverter X2 having an input terminal connected to the second node N2, an output terminal connected to the first node N1, and an output terminal connected to the second voltage signal output terminal VGL;

the first capacitor C1, one end of which is electrically connected to the second end of the brightness adjustment unit 21, and the other end of which is connected to a first node N1;

and the first resistor R1 has one end electrically connected to the third end of the brightness adjusting unit 21 and the other end connected to a second node N2.

A first node N1 electrically connected to the output terminal of the second inverter X2, the first capacitor C1, and the light emitting module 3, respectively;

a second node N2 electrically connected to the output terminal of the first inverter X1, the input terminal of the second inverter X2, and the first resistor R1, respectively;

compared with the RC oscillation circuit in the prior art, the oscillator module 2 provided in this embodiment has the first inverter X1 and the second inverter X2 disposed in the oscillator module 2, and the principle of the inverters is to invert the phase of the input signal by 180 degrees, so that the first inverter X1 and the second inverter X2 are connected in series in the pixel driving circuit, and the signal received at the first node N1 can be controlled to be a square wave signal. It can be understood that, when the signal inputted to the input terminal of the first inverter X1 is a low-level signal, and is converted into a low-level signal by the first inverter X1 and transmitted to the second node N2, the second node N2 transmits a low-level signal to the input terminal of the second inverter X2, and is converted into a high-level signal by the second inverter X2 and transmitted to the first node N1; according to the principle of generating square wave signals by an oscillator, a signal at the input end of the first inverter X1 is converted into a high potential signal after a low potential signal continues for a period, the high potential signal is converted into a high potential signal through the first inverter X1 and is sent to the second node N2, at this time, the high potential signal is sent to the input end of the second inverter X2 by the second node N2, the high potential signal is converted into a low potential signal through the second inverter X2 and is sent to the first node N1, and then the square wave signals are generated at the first node N1.

Further, the brightness adjusting unit 21 controls the internal resistance of the oscillator module 2, so as to adjust the duty ratio of the square wave signal generated by the oscillator module 2, control the occupied time proportion of the first signal in one square wave signal to increase, and further regulate and control the brightness of the light emitting module 3.

Fig. 9 is a timing diagram before adjustment of the pixel driving circuit of fig. 8, fig. 10 is a timing diagram after adjustment of the pixel driving circuit of fig. 8, and referring to fig. 9 and fig. 10, the data writing module 1 writes the data signal din into the oscillator module 2 in a first phase corresponding to the scan signal gin, and the oscillator module 2 oscillates to generate a square wave signal, generates the square wave signal at a position of a first node N1, and transmits the first signal to the light emitting module 3 in a second phase and a third phase, wherein the oscillator module comprises a first inverter X1 and a second inverter X2, an output end of the first inverter X1 is opposite to a signal at an output end of the second inverter X2, that is, potentials of the second node N2 and the first node N1 are opposite in the same time period; in the fourth stage, the light emitting module emits light in response to the first signal transmitted from the first node N1. It can be understood that, when the data signal din is not adjusted, the value of the data signal din is 0V, the square wave signal generated by oscillation of the oscillator module is as shown in fig. 9, the first signal is a low-level signal, and the second signal is a high-level signal. And then adjust data signal din, rise its signal to 2V, the square wave signal that the oscillation of oscillator module produced at this moment is as shown in fig. 10, can obviously derive the duty cycle that has increased the first signal, and then can be favorable to improving luminous efficiency.

Fig. 11 is still another pixel driving circuit provided by the present invention, and the brightness adjusting unit in the pixel driving circuit 200 includes: a second resistor R2, a first transistor T1, a second transistor T2, a third transistor T3;

a first transistor T1 having a first terminal electrically connected to the second resistor R2, a second terminal connected to the fourth node N4, and a control terminal connected to the data writing module 1;

a second transistor T2, having a first terminal connected to the fourth node N4, a second terminal connected to the fifth node N5, a control terminal connected to the fourth node N4, and a fourth node N4 being a third terminal of the brightness adjusting unit 21;

a third transistor T3, having a first terminal connected to the fifth node N5, a second terminal electrically connected to the second resistor R2, a control terminal connected to the fifth node N5, and a fifth stage N5 being the second terminal of the brightness adjusting unit 21;

a first capacitor C1 having one end connected to the fifth node N5 and the other end connected to the first node N1;

a second resistor R2 having one end electrically connected to the first end of the first transistor T1 and the other end electrically connected to the second end of the third transistor T3;

and a first resistor R1 having one end electrically connected to the output end of the first inverter and the input end of the second inverter, and the other end connected to the fourth node N4.

The fourth node N4 is electrically connected to one end of the first resistor R1, the second end of the first transistor T1, the first end of the second transistor T2, and the control terminal, respectively; the fifth node N5 is electrically connected to the second terminal of the second transistor T2, the first terminal of the first capacitor C1, the first terminal of the third transistor T3, and the control terminal, respectively, and in this embodiment, only the first transistor T1, the second transistor T2, and the third transistor T3 are taken as N-type transistors as an example, which is only one embodiment of the present invention, and other embodiments also belong to the protection scope of the present invention, but not limiting the present invention, and the first transistor T1, the second transistor T2, and the third transistor T3 in the present invention may also all adopt N-type transistors, or a mixture of P-type transistors and N-type transistors.

It can be understood that, according to the principle that the resistance of the first transistor T1 is variable when the resistance is turned on, the resistance value of the first transistor T1 can be adjusted, so that the duty ratio of the square wave signal at the position of the first node N1 can be controlled, the proportion of the occupied time of the first signal in one square wave signal is increased, and the luminance of the light emitting module 3 is adjusted.

With continued reference to fig. 9 and 10, the data writing module 1 writes the data signal din into the oscillator module 2 in response to the scan signal gin in the first phase, and generates a square wave signal in the oscillator module 2 in the second phase and the third phase, and generates the square wave signal at the position of the first node N1 and sends the first signal to the light emitting module 3, wherein the oscillator module includes a first inverter X1 and a second inverter X2, and the output end of the first inverter X1 is opposite to the signal at the output end of the second inverter X2, that is, the potentials of the second node N2 and the first node N1 are opposite in the same time period; in the fourth stage, the light emitting module emits light in response to the first signal transmitted from the first node N1. It can be understood that, when the data signal din is not adjusted, the value of the data signal din is 0V, the square wave signal generated by oscillation of the oscillator module is as shown in fig. 9, the first signal is a low-level signal, and the second signal is a high-level signal. Further, the data signal din is adjusted to raise the signal to 2V, the resistance value of the first transistor T1 in the oscillator module 2 decreases with the increase of the value of the data signal din, and further the duty ratio of the square wave signal generated in the oscillator module 2 can be increased, and as shown in fig. 10, the duty ratio of the first signal can be obviously increased by the square wave signal generated by oscillation of the oscillator module, so that the improvement of the light emitting efficiency can be facilitated.

Fig. 12 is still another pixel driving circuit provided by the present invention, in which the first inverter X1 in the pixel driving circuit 200 includes a fourth transistor T4 and a fifth transistor T5 connected in series between the first voltage signal output terminal VGH and the second voltage signal output terminal VGL;

a fourth transistor T4, a first terminal of which is electrically connected to the first voltage signal output terminal VGH, a second terminal of which is electrically connected to the first terminal of the fifth transistor T5 and the second node N2, and a control terminal of which is connected to the fifth node N5;

a first terminal of the fifth transistor T5 is electrically connected to the second terminal of the fourth transistor T4 and the second node N2, a second terminal thereof is electrically connected to the second voltage signal output terminal VGL, and a control terminal thereof is connected to the fifth node N5.

With continued reference to fig. 12, the second inverter X2 in the pixel driving circuit 200 includes a sixth transistor T6 and a seventh transistor T7 connected in series between the first voltage signal output terminal VGH and the second voltage signal output terminal VGL;

a sixth transistor T6 having a first terminal electrically connected to the first voltage signal output terminal VGH, a second terminal electrically connected to the first terminal of the seventh transistor T7 and the first node N1, and a control terminal connected to the second node N2;

a first terminal of the seventh transistor T7 is electrically connected to the second terminal of the sixth transistor T6 and the second node N2, a second terminal thereof is electrically connected to the second voltage signal output terminal VGL, and a control terminal thereof is connected to the second node N2. Wherein, the fourth transistor T4 and the sixth transistor T6 are transistors of the same type, the fifth transistor T5 and the seventh transistor T7 are transistors of the same type, and the types of the two transistors in the same inverter are different, only the fourth transistor T4 and the sixth transistor T6 are illustrated as P-type transistors in this embodiment; the fifth transistor T5 and the seventh transistor T7 are N-type transistors.

It is understood that when the enable signal at the input terminal of the first inverter X1 is low, the fourth transistor T4 is turned on and the fifth transistor T5 is turned off, the low signal is converted into a high signal through the first inverter X1 to the second node N2, the second node N2 transmits the high signal to the input terminal of the second inverter X2, the sixth transistor T6 is turned off and the seventh transistor T7 is turned on, and the high potential is converted into a low potential signal through the second inverter X2 to the first node N1, at this time, the signal output by the high power voltage signal terminal VGH is transmitted to the low power voltage signal terminal VSL through the fourth transistor T4, the second node N2, the first resistor R1, the fourth node N4, the second transistor T2, the first capacitor C1 and the seventh transistor T7 in sequence, meanwhile, the first node transmits the first signal to the light emitting module 3, and the light emitting module 3 emits light corresponding to the first signal. When the enable signal at the input terminal of the second inverter X2 is high, the fourth transistor T4 is turned off and the fifth transistor T5 is turned on, the high signal is converted into a low signal through the first inverter X1 to the second node N2, the second node N2 transmits the low signal to the input terminal of the second inverter X2, the sixth transistor T6 is turned on and the seventh transistor T7 is turned off, and the low potential is converted into a high potential signal through the second inverter X2 to the first node N1, at this time, the signal output from the high power voltage signal terminal VGH is sequentially transmitted to the low power voltage signal terminal VSL through the sixth transistor T6, the first node N1, the first capacitor C1, the fifth node N5, the third transistor T3, the second resistor R2, the first transistor T1, the fourth node N4, the first resistor R1 and the fifth transistor T5, while the first node sends a second signal to the light emitting module 3, the light emitting module 3 does not emit light in response to the second signal.

It can be further understood that, since the current signal flows through the first transistor T1, and then the magnitude of the signal responded by the gate of the first transistor T1 is adjusted by the data signal din, the resistance of the first transistor T1 itself is controlled, at this time, the resistance of the first transistor T1 is adjustable, and in combination with the second capacitor, at this time, the duration of the second signal in the square wave signal at the position of the first node N1 is intentionally adjusted according to the data signal din, so as to adjust and control the duration of the second signal, and then control the duty ratio of the square wave signal, the duration duty ratio of the second signal can be reduced, the duration of the first signal is improved, and the light emitting efficiency of the light emitting module 3 is improved.

Fig. 13 is a flowchart of a driving method of a pixel driving circuit according to still another embodiment of the present invention, and referring to fig. 12 and 13 successively, the present embodiment provides a driving method of a pixel driving circuit, for the pixel driving circuit shown in fig. 7, the driving method includes the steps of:

step 201, in the first stage, a data writing module responds to a scanning signal and writes a data signal into an oscillator module;

202, in the second stage, the first transistor, the second transistor, the fourth transistor and the seventh transistor are switched on, signals output by the high power supply voltage signal end are controlled to be transmitted to the low power supply voltage signal end through the fourth transistor, the first resistor, the second transistor and the seventh transistor in sequence, and meanwhile the output end of the second inverter transmits the first signals to the light emitting module;

it can be understood that the second phase is a charging phase, when the enable signal at the input terminal of the first inverter X1 is at a low level, the fourth transistor T4 is controlled to be turned on and the fifth transistor T5 is turned off, the low level signal is converted into a high level signal through the first inverter X1 to the second node N2, the second node N2 transmits the high level signal to the input terminal of the second inverter X2, when the sixth transistor T6 is turned off and the seventh transistor T7 is turned on, and the high level signal is converted into a low level signal through the second inverter X2 to the first node N1, at this time, the signal output from the high power voltage signal terminal VGH is transmitted to the low power voltage signal terminal VSL through the fourth transistor T4, the second node N2, the first resistor R1, the fourth node N4, the second transistor T2, the first capacitor C1, and the seventh transistor T7 in sequence, and at the same time, the first node N1 transmits the first signal at this time to the light emitting module 3, the light emitting module 3 emits light in response to the first signal.

In the third stage, the first transistor, the second transistor, the third transistor, the fifth transistor and the sixth transistor are turned on, signals output by the high power supply voltage signal end are controlled to be output to the low power supply voltage signal end sequentially through the sixth transistor, the first capacitor, the third transistor, the second resistor, the first transistor, the first resistor and the fifth transistor, meanwhile, the first transistor responds to data signals to adjust the resistance value of the resistor of the first transistor, the output end of the second inverter is controlled to transmit the second signals to the light emitting module, and the duration of transmitting the second signals is controlled.

It is understood that, with continuing reference to fig. 9 and 10, the third stage is a discharging stage, when the enable signal at the input terminal of the second inverter X2 is at a high level, when the fourth transistor T4 is turned off and the fifth transistor T5 is turned on, the high level signal is converted into a low level signal through the first inverter X1 to the second node N2, the second node N2 transmits the low level signal to the input terminal of the second inverter X2, when the sixth transistor T6 is turned on and the seventh transistor T7 is turned off, and the low level signal is converted into a high level signal through the second inverter X2 to the first node N1, when the signal output from the high power voltage signal terminal VGH passes through the sixth transistor T6, the first node N1, the first capacitor C1, the fifth node N5, the third transistor T3, the second resistor R2, the first transistor T1, the fourth node N4, the first resistor R1, and the fifth transistor T5 in sequence, meanwhile, the first node N1 transmits a second signal to the light emitting module 3, and the light emitting module 3 does not emit light in response to the second signal.

Step 204, in the fourth stage, the light emitting module emits light in response to the first signal.

It can be understood that, in the third phase, since the current signal flows through the first transistor T1, and then the magnitude of the signal responded by the gate of the first transistor T1 is adjusted by the data signal din, the resistance of the first transistor T1 itself is controlled, at this time, the resistance of the first transistor T1 is adjustable, and in combination with the first capacitor C1, at this time, the duration of the second signal in the square wave signal at the position of the first node N1 can be adjusted according to the data signal din, so as to adjust and control the duration of the second signal, and then control the duty ratio of the square wave signal, the duration of the second signal can be reduced, the duration of the first signal is increased, and the light emitting efficiency of the light emitting module 3 is increased.

Fig. 14 is still another pixel driving circuit provided by the present invention, and the data writing module in the pixel driving circuit 200 includes an eighth transistor T8 and a second capacitor C2; an eighth transistor T8 having a first terminal connected to the data signal input terminal din, a second terminal electrically connected to the oscillator module, a second terminal connected to the third node N3, and a control terminal connected to the scan signal input terminal gin; and a second capacitor C2 having one end electrically connected to the first voltage signal output terminal VGH and the other end electrically connected to the gate terminal of the first transistor T1 in the luminance adjusting unit 21. In this embodiment, only the case that the eighth transistor T8 is an N-type transistor is shown, and certainly, the eighth transistor T8 may be a P-type transistor, and the type of the eighth transistor T8 may be set according to an actual situation, and only needs to be matched with the rest of the transistors in the pixel driving circuit, which is not described in detail below.

Fig. 15 is still another pixel driving circuit provided by the present invention, and a light emitting module in the pixel driving circuit 200 includes a ninth transistor T9 and a light emitting element O connected in series between a first power voltage input terminal Pvdd and a second power voltage input terminal Pvee; a ninth transistor T9 having a first terminal connected to the first power voltage input terminal Pvdd, a second terminal electrically connected to one terminal of the light emitting element O, and a control terminal connected to the first node; and a light emitting element O having one end electrically connected to the second end of the ninth transistor T9 and the other end connected to a second power voltage input terminal Pvee.

The ninth transistor T9 is a P-type transistor, and since the ninth transistor T9 is a P-type transistor disposed in the pixel driving circuit, the first signal transmitted by the first node N1 is a low-potential signal, the ninth transistor T9 is turned on in response to the low-potential signal, and then the signal at the first power voltage input terminal Pvdd flows through the ninth transistor T9 and the light emitting device O to the second power voltage input terminal Pvee, and the light emitting device O emits light. The second signal transmitted by the first node N1 is a high level signal, the ninth transistor T9 is turned off in response to the high level signal, and the light emitting element O does not emit light by no current.

It can be understood that the data signal din controls the resistance of the first transistor T1, and further controls the duty ratio of the duration of the second signal at the first node N1, and the duty ratio of the duration of the non-light-emitting of the light-emitting element O is controlled, which is beneficial to improving the light-emitting efficiency of the light-emitting element O.

With continued reference to fig. 15, the light emitting elements are micro-leds or sub-millimeter leds. The submillimeter LED Mini-LED is a submillimeter LED, and the size of a single LED is about 100 microns. The light-emitting element is a Micro-LED (light-emitting diode), which is a Micro-LED (light-emitting diode) in a Micro and matrix mode, and the LED is subjected to film, Micro and array design, so that the LED can be smaller than 50 micrometers.

Based on the same inventive concept, the present invention further provides a display panel including the pixel driving circuit 200 according to any one of the above embodiments. Referring to fig. 16, fig. 16 is a display panel provided by the present invention. Fig. 16 provides a display panel 300 including the pixel driving circuit 200 according to any of the above embodiments of the invention. The embodiment of fig. 16 is described by using a mobile phone as a display panel, and it should be understood that the display provided in the embodiment of the present invention may be other display panels with display functions, such as a computer, a television, a tablet computer, an electronic book, and a vehicle-mounted display panel, and the present invention is not limited thereto. The display panel provided in the embodiment of the present invention has the beneficial effects of the display panel provided in the embodiment of the present invention, and specific descriptions on the display panel in the above embodiments may be specifically referred to, and the detailed descriptions in this embodiment are not repeated herein. It should be noted that, the transistors used in the embodiments of the present invention are all P-type transistors, but the present invention is not limited thereto, and the present invention may also all use N-type transistors, or a mixture of P-type transistors and N-type transistors, so long as the logic of the pixel driving circuit is ensured. And thus the type of each transistor is not limited.

As can be seen from the foregoing embodiments, the pixel driving circuit, the driving method thereof, and the display panel provided by the present invention at least achieve the following advantages:

the invention discloses a pixel driving circuit, a driving method thereof and a display panel, comprising the following steps: the data writing module is used for responding to the current scanning signal and transmitting the data signal voltage to the oscillator module; the oscillator module is used for generating a square wave signal to the light-emitting module according to the data signal voltage transmitted by the data writing module and adjusting the proportion of the first signal holding time of the square wave signal; and the light emitting module is used for emitting light in response to the first signal of the square wave signal. The square wave signal is generated through the oscillator module, the duty ratio of the square wave signal can be adjusted through the oscillator module, the square wave signal can control the light emitting condition of the light emitting module, the light emitting condition of the light emitting module can be adjusted through the adjusting and controlling oscillator module, the brightness of the light emitting module is controlled, and the light emitting efficiency of the display panel is improved.

Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A pixel driving circuit, comprising:

the oscillator module is used for generating a square wave signal to the light-emitting module according to the data signal voltage transmitted by the data writing module and adjusting the proportion of the first signal holding duration of the square wave signal;

the oscillator module comprises a first phase inverter, a second phase inverter, a first capacitor, a first resistor and a brightness adjusting unit;

the first end of the brightness adjusting unit is electrically connected with the data writing module, the second end of the brightness adjusting unit is electrically connected with the input end of the first inverter and the first node, and the third end of the brightness adjusting unit is electrically connected with the second node;

the input end of the first inverter is electrically connected with the second end of the brightness adjusting unit, and the output end of the first inverter is connected to the second node;

the input end of the second inverter is connected to the second node, and the output end of the second inverter is connected to the first node;

one end of the first capacitor is electrically connected with the second end of the brightness adjusting unit, and the other end of the first capacitor is connected to a first node;

one end of the first resistor is electrically connected with the third end of the brightness adjusting unit, and the other end of the first resistor is connected to a second node;

the brightness adjustment unit includes: the second resistor, the first transistor, the second transistor and the third transistor;

the first end of the first transistor is electrically connected with the second resistor, the second end of the first transistor is connected to a fourth node, and the control end of the first transistor is electrically connected with the data writing module;

a first end of the second transistor is connected to the fourth node, a second end of the second transistor is connected to the fifth node, and a control end of the second transistor is connected to the fourth node;

the first end of the third transistor is connected to the fifth node, the second end of the third transistor is electrically connected with the second resistor, and the control end of the third transistor is connected to the fifth node;

and one end of the second resistor is electrically connected with the first end of the first transistor, and the other end of the second resistor is electrically connected with the second end of the third transistor.

2. The pixel driving circuit according to claim 1, wherein the first inverter includes a fourth transistor and a fifth transistor connected in series between a first voltage signal output terminal and a second voltage signal output terminal;

a first end of the fourth transistor is electrically connected with the first voltage signal output end, a second end of the fourth transistor is electrically connected with a first end of the fifth transistor and the second node, and a control end of the fourth transistor is connected to the fifth node;

and a first end of the fifth transistor is electrically connected with a second end of the fourth transistor and the second node, a second end of the fifth transistor is electrically connected with the second voltage signal output end, and a control end of the fifth transistor is connected to the fifth node.

3. The pixel driving circuit according to claim 2, wherein the second inverter includes a sixth transistor and a seventh transistor connected in series between the first voltage signal output terminal and the second voltage signal output terminal;

a first end of the sixth transistor is electrically connected with the first voltage signal output end, a second end of the sixth transistor is electrically connected with a first end of the seventh transistor and the first node, and a control end of the sixth transistor is connected to the second node;

and a first end of the seventh transistor is electrically connected with a second end of the sixth transistor and the second node, a second end of the seventh transistor is electrically connected with the second voltage signal output end, and a control end of the seventh transistor is connected to the second node.

4. The pixel driving circuit according to claim 1, wherein the data writing module comprises an eighth transistor and a second capacitor;

the first end of the eighth transistor is connected to the data signal input end, the second end of the eighth transistor is electrically connected with the oscillator module, and the control end of the eighth transistor is connected to the scanning signal input end;

and one end of the second capacitor is electrically connected with the first voltage signal output end, and the other end of the second capacitor is electrically connected with the brightness adjusting unit.

5. The pixel driving circuit according to claim 1, wherein the light emitting module includes a ninth transistor and a light emitting element connected in series between a first power supply voltage input terminal and a second power supply voltage input terminal;

a first end of the ninth transistor is connected to the first power voltage input end, a second end of the ninth transistor is electrically connected with one end of the light-emitting element, and a control end of the ninth transistor is connected to the first node;

and a light emitting element having one end electrically connected to the second end of the ninth transistor and the other end connected to the second power supply voltage input terminal.

6. The pixel driving circuit according to claim 3, wherein the fourth transistor and the sixth transistor are P-type transistors;

the fifth transistor and the seventh transistor are N-type transistors.

7. The pixel driving circuit according to claim 5, wherein the ninth transistor is a P-type transistor.

8. The pixel driving circuit according to claim 1, wherein the light emitting element is a micro light emitting diode or a sub-millimeter light emitting diode.

9. A display panel comprising the pixel driving circuit according to any one of claims 1 to 8.

10. A driving method of a pixel driving circuit, the pixel driving circuit comprising:

the first inverter comprises a fourth transistor and a fifth transistor which are connected in series between a first voltage signal output end and a second voltage signal output end;

a first end of the fourth transistor is electrically connected with the first voltage signal output end, a second end of the fourth transistor is electrically connected with a first end and a second node of the fifth transistor, and a control end of the fourth transistor is connected to a fifth node;

a first end of the fifth transistor is electrically connected with a second end of the fourth transistor and the second node, a second end of the fifth transistor is electrically connected with the second voltage signal output end, and a control end of the fifth transistor is connected to the fifth node;

the second inverter includes a sixth transistor and a seventh transistor connected in series between the first voltage signal output terminal and the second voltage signal output terminal;

a first end of the sixth transistor is electrically connected with the first voltage signal output end, a second end of the sixth transistor is electrically connected with a first end and a first node of the seventh transistor, and a control end of the sixth transistor is connected to the second node;

a first end of the seventh transistor is electrically connected with a second end of the sixth transistor and the second node, a second end of the seventh transistor is electrically connected with the second voltage signal output end, and a control end of the seventh transistor is connected to the second node;

the second resistor has one end electrically connected to the first end of the first transistor and the other end electrically connected to the second end of the third transistor;

the driving method includes the steps of;

a first stage in which the data write module writes the data signal into the oscillator module in response to the scan signal;

in the second stage, the first transistor, the second transistor, the fourth transistor and the seventh transistor are turned on, so that a signal output by the high power supply voltage signal end is controlled to be transmitted to the low power supply voltage signal end through the fourth transistor, the first resistor, the second transistor and the seventh transistor in sequence, and meanwhile, the output end of the second inverter transmits the first signal to the light emitting module;

in a third stage, the first transistor, the second transistor, the third transistor, the fifth transistor and the sixth transistor are turned on, signals output by the high power supply voltage signal end are controlled to be output to the low power supply voltage signal end sequentially through the sixth transistor, the first capacitor, the third transistor, the second resistor, the first transistor, the first resistor and the fifth transistor, meanwhile, the first transistor adjusts the resistance value of the resistor thereof in response to the data signal, the output end of the second inverter is controlled to transmit a second signal to the light emitting module, and the duration of transmitting the second signal is controlled;