阅读说明：本技术 发光器件驱动电路、背光模组以及显示面板 (Light emitting device driving circuit, backlight module and display panel ) 是由 李艳 于 2021-07-20 设计创作，主要内容包括：本申请实施例提供的发光器件驱动电路、背光模组以及显示面板,包括发光器件、驱动晶体管、数据信号写入晶体管以及第一侦测模块。采用第一侦测模块侦测数据信号写入晶体管的阈值电压,并采用外部补偿的方式对数据信号写入晶体管的阈值电压进行有效补偿,从而改善发光器件驱动电路的电流均一性,进而改善显示器件的光学特性。(The light-emitting device driving circuit, the backlight module and the display panel provided by the embodiment of the application comprise a light-emitting device, a driving transistor, a data signal writing transistor and a first detection module. The first detection module is used for detecting the threshold voltage of the data signal writing transistor, and the threshold voltage of the data signal writing transistor is effectively compensated in an external compensation mode, so that the current uniformity of the light-emitting device driving circuit is improved, and the optical characteristics of the display device are improved.)

1. A light emitting device driving circuit, comprising:

the light-emitting device is connected in series with a light-emitting loop formed by a first power signal and a second power signal;

the source electrode of the driving transistor and the drain electrode of the driving transistor are connected in series with the light-emitting loop, and the grid electrode of the driving transistor is electrically connected to a first node;

a data signal writing transistor, wherein a grid electrode of the data signal writing transistor is connected with a scanning signal, a source electrode of the data signal writing transistor is connected with a data signal, and a drain electrode of the data signal writing transistor is electrically connected with the first node; and

the first detection module is connected to a first control signal and electrically connected to the first node, and is used for detecting the voltage of the first node under the control of the first control signal to acquire the threshold voltage of the data signal write-in transistor and adjust the data signal based on the threshold voltage of the data signal write-in transistor.

2. The light-emitting device driving circuit according to claim 1, wherein the first detection module comprises a first transistor and a first detection unit;

the gate of the first transistor is connected to the first control signal, the source of the first transistor is electrically connected to the first node, and the drain of the first transistor is electrically connected to the first detection unit; the first detection unit is configured to detect a voltage of the first node to obtain a threshold voltage of the data signal writing transistor, and adjust the data signal based on the threshold voltage of the data signal writing transistor.

3. The light-emitting device driving circuit according to claim 1, further comprising a storage capacitor;

one end of the storage capacitor is electrically connected with the first node, and the other end of the storage capacitor is connected to the second power supply signal.

4. The light emitting device driving circuit according to claim 1, further comprising a second detection module, wherein the second detection module is connected to a second control signal and electrically connected to the drain of the driving transistor, and the second detection module is configured to detect the drain of the driving transistor under the control of the second control signal to obtain a threshold voltage of the driving transistor, and adjust the data signal based on the threshold voltage of the driving transistor.

5. The light-emitting device driving circuit according to claim 4, wherein the second detection module comprises a second transistor and a second detection unit;

the gate of the second transistor is connected to the second control signal, the source of the second transistor is electrically connected to the drain of the driving transistor, the drain of the second transistor is electrically connected to the second detecting unit, and the second detecting unit is configured to obtain the threshold voltage of the driving transistor and adjust the data signal based on the threshold voltage of the driving transistor.

6. The circuit of claim 1, further comprising a light-emitting control module, wherein the light-emitting control module is connected to a light-emitting control signal and is connected to the light-emitting circuit in series, and the light-emitting control module is configured to control the light-emitting circuit to be turned on or off based on the light-emitting control signal.

7. The light-emitting device driving circuit according to claim 6, wherein the light emission control module includes a light emission control transistor;

the grid electrode of the light-emitting control transistor is connected with the light-emitting control signal, the source electrode of the light-emitting control transistor is connected with the first power supply signal, and the drain electrode of the light-emitting control transistor is electrically connected with the source electrode of the driving transistor.

8. The pixel driving circuit according to claim 1, wherein a potential of the first power supply signal is larger than a potential of the second power supply signal.

9. A backlight module, comprising:

a data line for providing a data signal;

a scan line for providing a scan signal;

a light emission control signal line for providing a light emission control signal; and

the light emitting device driving circuit according to any one of claims 1 to 8, which is connected to the data line, the scan line, and the light emission control signal line.

10. A display panel comprising a plurality of pixel units arranged in an array, each of the pixel units comprising the light emitting device driving circuit according to any one of claims 1 to 8.

Technical Field

The application relates to the technical field of display, in particular to a light-emitting device driving circuit, a backlight module and a display panel.

Background

At present, a Micro Light Emitting Diode (Micro-LED) display device has the advantages of fast response, high color gamut, high resolution, low energy consumption and the like, but has many technical difficulties and complex technology, in particular to a mass transfer technology and a Light Emitting Diode (LED) particle miniaturization technology. The mini-LED display device is a product of combining the Micro-LED and the backplane, and has high contrast, high color rendering, and the like, which are comparable to those of an Organic Light Emitting Diode (OLED) display device, and the cost is lower than that of an OLED display device. In addition, mini-LED display devices are easier to implement than Micro-LED display devices and OLED display devices. Therefore, the mini-LED display device has become a hot spot for the layout of various large panel manufacturers.

Among them, the market has increasingly higher specification requirements for the subareas in the product specification of the mini-LED display device. And as the number of partitions increases, part of the components of the mini-LED display device operate in the saturation region of the transistor. The transistor has the problem of threshold voltage drift, so that the gate voltage of the transistor is influenced, and the optical characteristics of the mini-LED display device are further influenced.

Therefore, how to compensate the threshold voltage of the transistor in the pixel driving circuit to prevent it from affecting the optical characteristics of the mini-LED display device is a difficult problem for the manufacturers of the existing panels to struggle with.

Disclosure of Invention

An object of the embodiments of the present application is to provide a light emitting device driving circuit, a backlight module and a display panel, which can solve the technical problem of threshold voltage drift of a transistor of the existing light emitting device driving circuit.

The embodiment of the present application provides a light emitting device driving circuit, including:

the light-emitting device is connected in series with a light-emitting loop formed by a first power signal and a second power signal;

the source electrode of the driving transistor and the drain electrode of the driving transistor are connected in series with the light-emitting loop, and the grid electrode of the driving transistor is electrically connected to a first node;

a data signal writing transistor, wherein a grid electrode of the data signal writing transistor is connected with a scanning signal, a source electrode of the data signal writing transistor is connected with a data signal, and a drain electrode of the data signal writing transistor is electrically connected with the first node; and

the first detection module is connected to a first control signal and electrically connected to the first node, and is used for detecting the voltage of the first node under the control of the first control signal to acquire the threshold voltage of the data signal write-in transistor and adjust the data signal based on the threshold voltage of the data signal write-in transistor.

In the light emitting device driving circuit of the present application, the first detecting module includes a first transistor and a first detecting unit;

the gate of the first transistor is connected to the first control signal, the source of the first transistor is electrically connected to the first node, and the drain of the first transistor is electrically connected to the first detection unit; the first detection unit is configured to detect a voltage of the first node to obtain a threshold voltage of the data signal writing transistor, and adjust the data signal based on the threshold voltage of the data signal writing transistor.

In the light emitting device driving circuit described herein, the light emitting device driving circuit further includes a storage capacitor;

one end of the storage capacitor is electrically connected with the first node, and the other end of the storage capacitor is connected to the second power supply signal.

In the light emitting device driving circuit of the present application, the light emitting device driving circuit further includes a second detection module, the second detection module is connected to the second control signal and is electrically connected to the drain of the driving transistor, and the second detection module is used for detecting the drain of the driving transistor under the control of the second control signal to obtain the threshold voltage of the driving transistor and adjust the data signal based on the threshold voltage of the driving transistor.

In the light emitting device driving circuit of the present application, the second detecting module includes a second transistor and a second detecting unit;

the gate of the second transistor is connected to the second control signal, the source of the second transistor is electrically connected to the drain of the driving transistor, the drain of the second transistor is electrically connected to the second detecting unit, and the second detecting unit is configured to obtain the threshold voltage of the driving transistor and adjust the data signal based on the threshold voltage of the driving transistor.

In the present application, the light emitting device driving circuit further includes a light emitting control module, the light emitting control module is connected to the light emitting control signal and connected in series to the light emitting loop, and the light emitting control module is used for controlling the light emitting loop to be turned on or turned off based on the light emitting control signal.

In the light emitting device driving circuit described herein, the light emission control module includes a light emission control transistor;

the grid electrode of the light-emitting control transistor is connected with the light-emitting control signal, the source electrode of the light-emitting control transistor is electrically connected with the first power supply signal, and the drain electrode of the light-emitting control transistor is electrically connected with the source electrode of the driving transistor.

In the pixel driving circuit described herein, the potential of the first power supply signal is greater than the potential of the second power supply signal.

The embodiment of the present application further provides a backlight module, including:

a data line for providing a data signal;

a scan line for providing a scan signal;

a light emission control signal line for providing a light emission control signal; and

the light emitting device driving circuit as described above, which is connected to the data lines, the scan lines and the light emission control signal lines

The embodiment of the application further provides a display panel, which comprises a plurality of pixel units arranged in an array, wherein each pixel unit is provided with the light-emitting device driving circuit.

The light emitting device driving circuit, the backlight module and the display panel provided by the embodiment of the application comprise a light emitting device, a driving transistor, a first detection module and a data signal writing transistor. The first detection module is used for detecting the voltage of the first node, and the threshold voltage of the data signal writing transistor is calculated according to the voltage of the first node. The data signal is adjusted by adopting an external compensation mode according to the threshold voltage of the data signal writing transistor so as to effectively compensate the threshold voltage of the data signal writing transistor, thereby improving the current uniformity of the light-emitting device driving circuit and further improving the optical characteristics of the display device.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a first implementation manner of a light emitting device driving circuit provided in an embodiment of the present application.

Fig. 2 is a first circuit diagram of a first implementation manner of a light emitting device driving circuit provided in an embodiment of the present application.

Fig. 3 is a second circuit schematic diagram of a first implementation manner of a light emitting device driving circuit provided in an embodiment of the present application.

Fig. 4 is a timing diagram of a first implementation manner of a light emitting device driving circuit provided in an embodiment of the present application.

Fig. 5 is a schematic structural diagram of a second implementation manner of a light emitting device driving circuit provided in an embodiment of the present application.

Fig. 6 is a circuit schematic diagram of a second implementation manner of a light emitting device driving circuit provided in an embodiment of the present application.

Fig. 7 is a timing diagram of a second implementation manner of a light emitting device driving circuit provided in an embodiment of the present application.

Fig. 8 is a schematic structural diagram of a third implementation of a light emitting device driving circuit provided in an example of the present application.

Fig. 9 is a circuit diagram of a third implementation manner of a light emitting device driving circuit provided in an example of the present application.

Fig. 10 is a timing diagram of a third embodiment of a light emitting device driving circuit according to an example of the present application.

Fig. 11 is a schematic path diagram of an initialization stage of a light emitting device driving circuit according to an embodiment of the present application at the driving timing shown in fig. 10.

Fig. 12 is a schematic path diagram of a pixel driving circuit in the threshold voltage detection stage at the driving timing shown in fig. 10 according to an embodiment of the present disclosure.

Fig. 13 is a schematic path diagram of a pixel driving circuit provided in the embodiment of the present application in a threshold voltage compensation stage under the driving timing shown in fig. 10.

Fig. 14 is a schematic structural diagram of a backlight module according to an embodiment of the present application.

Fig. 15 is a schematic structural diagram of a display panel according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The transistors used in all embodiments of the present application may be thin film transistors or field effect transistors or other devices with the same characteristics, and since the source and drain of the transistors used herein are symmetrical, the source and drain may be interchanged. In the embodiment of the present application, to distinguish two poles of a transistor except for a gate, one of the two poles is referred to as a source, and the other pole is referred to as a drain. The form in the drawing provides that the middle end of the switching transistor is a grid, the signal input end is a source, and the output end is a drain. In addition, the transistors used in the embodiments of the present application may include a P-type transistor and/or an N-type transistor, where the P-type transistor is turned on when the gate is at a low level and turned off when the gate is at a high level, and the N-type transistor is turned on when the gate is at a high level and turned off when the gate is at a low level.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a first implementation manner of a light emitting device driving circuit provided in an embodiment of the present application. As shown in fig. 1, the light emitting device driving circuit 10 according to the embodiment of the present disclosure includes a light emitting device D, a driving transistor T1, a data signal writing transistor T2, and a first detecting module 101. It should be noted that the light emitting device D may be a mini light emitting diode, a micro light emitting diode or an organic light emitting diode.

The light emitting device D is connected in series to a light emitting loop formed by the first power signal VLED and the second power signal VSS. The source of the driving transistor T1 and the drain of the driving transistor T1 are connected in series to the light emitting circuit. The gate of the driving transistor T1 is electrically connected to the first node P. The gate of the data signal writing transistor T2 is connected to the scan signal scan, the source of the data signal writing transistor T2 is connected to the data signal data, and the drain of the data signal writing transistor T2 is electrically connected to the first node P. The first detection module 101 receives the first control signal Rb and is electrically connected to the first node P.

It should be noted that, in the embodiment of the present application, it is only necessary to ensure that the light emitting device D is connected in series to the light emitting loop, and the light emitting device driving circuit 10 shown in fig. 1 only illustrates one specific position of the light emitting device D. That is, the light emitting device D may be connected in series at any position on the light emitting loop.

Specifically, the driving transistor T1 is used to control the current flowing through the light emitting loop. The first detecting module 101 is configured to detect a voltage of the first node P under the control of the first control signal Rb to obtain a threshold voltage of the data signal writing transistor T2, and adjust the data signal data based on the threshold voltage T2 of the data signal writing transistor. The data signal writing transistor T2 is for writing the data signal data to the gate of the driving transistor T1 under the control of the scan signal scan.

The light emitting device driving circuit 10 according to the embodiment of the application detects the potential of the first node P through the first detecting module 101, calculates the threshold voltage of the data signal writing transistor T2, and adds the threshold voltage of the data signal writing transistor T2 to the data signal data, so as to compensate the threshold voltage of the data signal writing transistor T2.

In some embodiments, the light emitting device driving circuit 10 provided by the embodiments of the present application includes a storage capacitor C. One end of the storage capacitor C is electrically connected to the first node P. The other end of the storage capacitor C is connected to a second power signal VSS. The storage capacitor C is used to store the potential of the first node P.

It should be noted that, in the embodiment of the present application, one end of the storage capacitor C may be electrically connected to the first node P, and the other end of the storage capacitor C may be electrically connected to the anode terminal of the light emitting device D. When the storage capacitor C is electrically connected to the first node P and is connected to the second power signal VSS, the light emitting device driving circuit 10 provided in the embodiment of the present application has better stability.

Referring to fig. 2, fig. 2 is a first circuit diagram of a light emitting device driving circuit according to a first embodiment of the present disclosure. Referring to fig. 1 and 2, the first detecting module 101 includes a first transistor T3 and a first detecting unit Sen. The gate of the first transistor T3 is switched on the first control signal Rb. The source of the first transistor T3 is electrically connected to the first node P. The drain of the first transistor T3 is electrically connected to the first detection unit Sen for detecting the voltage of the first node P to obtain the threshold voltage of the data signal writing transistor T2, and adjusting the data signal data based on the threshold voltage of the data signal writing transistor T2.

It should be noted that, the light emitting device driving circuit 10 according to the embodiment of the present application can detect the voltage of the first node P through the first detecting unit Sen by controlling the time node at which the first transistor T3 is turned on. While the light emitting device driving circuit 10 provided in the embodiment of the present application operates in the saturation region of the transistor, the voltage of the first node P is related to the gate voltage of the data signal writing transistor T2 and the threshold voltage of the data signal writing transistor T2. The threshold voltage of the data signal writing transistor T2 can be obtained by the voltage of the first node P and the voltage of the scan signal scan. The threshold voltage of the data signal writing transistor T2 is added to the data signal data to compensate the threshold voltage of the data signal writing transistor T2, so that the gate voltage of the driving transistor T1 is prevented from being affected by the drift of the threshold voltage of the data signal writing transistor T2, thereby improving the current uniformity of the light emitting device driving circuit 10 and improving the optical characteristics of the display device.

It should be noted that the first power signal VLED and the second power signal VSS are both used for outputting a predetermined voltage value. In addition, in the embodiment of the present application, the potential of the first power signal VLED is greater than the potential of the second power signal VSS. Specifically, the potential of the second power signal VSS may be the potential of the ground terminal. Of course, it is understood that the potential of the second power signal VSS may be other.

It should be noted that the driving transistor T1, the data signal writing transistor T2, and the first transistor T3 may be one or more of a low temperature polysilicon thin film transistor, an oxide semiconductor thin film transistor, or an amorphous silicon thin film transistor. Further, the transistors in the light emitting device driving circuit 10 provided in the embodiment of the present application may be set to be the same type of transistors, so as to avoid the influence on the light emitting device driving circuit 10 caused by the difference between different types of transistors.

Referring to fig. 3, fig. 3 is a second circuit diagram of a light emitting device driving circuit according to a first embodiment of the present disclosure. As shown in fig. 1 and fig. 3, in some embodiments, the light emitting device driving circuit 10 provided by the embodiment of the present application includes a storage capacitor C. One end of the storage capacitor C is electrically connected to the first node P. The other end of the storage capacitor C is connected to a second power signal VSS. The storage capacitor C is used to store the potential of the first node P.

Referring to fig. 4, fig. 4 is a timing diagram of a first implementation manner of a light emitting device driving circuit according to an embodiment of the present disclosure. The combination of the first control signal Rb and the scan signal scan sequentially corresponds to the initialization stage t1, the threshold voltage detection stage t2, and the threshold voltage compensation stage t 3; that is, within one frame time, the driving control timing of the light emitting device driving circuit 30 provided in the embodiment of the present application includes an initialization phase t1, a threshold voltage detection phase t2, and a threshold voltage compensation phase t 3.

It should be noted that the light emitting device D emits light during the threshold voltage detection period t2 and the threshold voltage compensation period t 3.

Specifically, in the initialization period t1, the scan signal scan is low, and the first control signal Rb is high.

Specifically, during the threshold voltage detecting period t2, the scan signal scan is high, and the first control signal Rb is high.

Specifically, during the threshold voltage compensation period t3, the scan signal scan is high, and the first control signal Rb is low.

Specifically, the first power signal VLED and the second power signal VSS are both dc voltage sources.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a second implementation manner of a light emitting device driving circuit according to an embodiment of the present disclosure. The light emission driving circuit 20 according to the present embodiment is different from the light emission driving circuit 10 according to the above-described embodiments in that:

the light emitting device driving circuit 20 provided by the present embodiment further includes a second detecting module 102. The second detecting module 102 receives the second control signal S _ g and is electrically connected to the drain of the driving transistor T1.

It should be noted that the second detecting module 102 is configured to detect the drain of the driving transistor T1 under the control of the second control signal S _ g to obtain the threshold voltage of the driving transistor T1, and adjust the data signal data based on the threshold voltage of the driving transistor T1.

Specifically, the second detecting module 102 is electrically connected to the second node Q. The anode terminal of the light emitting device is electrically connected to the second node Q. The drain of the driving transistor T1 is electrically connected to the second node Q.

The light emitting device driving circuit 20 provided in the embodiment of the application detects the potential of the second node Q through the second detecting module 102, calculates the threshold voltage of the driving transistor T1, and adjusts the data signal data based on the threshold voltage of the driving transistor T1, so as to compensate the threshold voltage of the driving transistor T1.

Referring to fig. 6, fig. 6 is a circuit diagram illustrating a light emitting device driving circuit according to a second embodiment of the present disclosure. As shown in fig. 5 and fig. 6, the second detecting module 102 includes a second transistor T4 and a second detecting unit S _ d. The gate of the second transistor T4 is connected to the second control signal S _ g. The source of the second transistor T4 is electrically connected to the drain of the driving transistor T1. The drain of the second transistor T4 is electrically connected to the second detection unit S _ d.

Specifically, the source of the second transistor T4 is electrically connected to the second node Q. The anode terminal of the light emitting device is electrically connected to the second node Q. The drain of the driving transistor T1 is electrically connected to the second node Q. The voltage of the second node Q is the drain voltage of the driving transistor T1.

It should be noted that, the light emitting device driving circuit 10 according to the embodiment of the present application can detect the voltage of the second node Q through the second detecting unit S _ d by controlling the time node when the second transistor T4 is turned on. The voltage of the second node Q is related to the threshold voltage of the driving transistor T1. The threshold voltage of the driving transistor T1 can be obtained by the voltage of the second node Q. The adjustment of the data signal data based on the threshold voltage of the driving transistor T1 can compensate the threshold voltage of the driving transistor T1, and prevent the threshold voltage drift of the driving transistor T1 from affecting the gate voltage value of the driving transistor T1, thereby improving the current uniformity of the light emitting device driving circuit 20 and further improving the optical characteristics of the display device.

It should be noted that the driving transistor T1, the data signal writing transistor T2, the first transistor T3, and the second transistor T4 may be one or more of a low temperature polysilicon thin film transistor, an oxide semiconductor thin film transistor, or an amorphous silicon thin film transistor. Further, the transistors in the light emitting device driving circuit 20 provided in the embodiment of the present application may be set to be the same type of transistors, so as to avoid the influence on the light emitting device driving circuit 20 caused by the difference between different types of transistors.

Referring to fig. 7, fig. 7 is a timing diagram of a light emitting device driving circuit according to a second embodiment of the present disclosure. The combination of the first control signal Rb, the second control signal S _ g and the scan signal scan sequentially corresponds to the initialization stage t1, the threshold voltage detection stage t2 and the threshold voltage compensation stage t 3; that is, within one frame time, the driving control timing of the light emitting device driving circuit 30 provided in the embodiment of the present application includes an initialization phase t1, a threshold voltage detection phase t2, and a threshold voltage compensation phase t 3.

It should be noted that the light emitting device D emits light during the threshold voltage detection period t2 and the threshold voltage compensation period t 3.

Specifically, in the initialization period t1, the scan signal scan is low, the first control signal Rb is high, and the second control signal S _ g is high.

Specifically, in the threshold voltage detection period t2, the scan signal scan is high, the first control signal Rb is high, and the second control signal S _ g is high.

Specifically, in the threshold voltage compensation phase t3, the scan signal scan is high, the first control signal Rb is low, and the second control signal S _ g is low.

Specifically, the first power signal VLED and the second power signal VSS are both dc voltage sources.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a third implementation of a light emitting device driving circuit according to an embodiment of the present disclosure. The light emission driving circuit 30 according to the present embodiment is different from the light emission driving circuit 20 according to the above-described embodiments in that: the light emitting device driving circuit 30 provided in the present embodiment further includes a light emission control module 103. The light emission control module 103 is connected to the light emission control signal EM and is connected in series to the light emission circuit.

The light emission control module 103 is configured to control the light emitting circuit to be turned on or off based on the light emission control signal EM. In the embodiment of the present application, it is only necessary to ensure that the light emission control module 103 is connected in series to the light emission loop, and the light emitting device driving circuit 10 shown in fig. 7 only illustrates one specific position of the light emission control module 103. That is, the light emission control module 103 may be connected in series at any position on the light emission circuit.

Referring to fig. 9, fig. 9 is a circuit diagram illustrating a third implementation manner of a light emitting device driving circuit according to an embodiment of the present disclosure. As shown in fig. 8 and 9, the light emission control module 103 includes a light emission control transistor T5. The gate of the emission control transistor T5 is connected to the emission control signal EM. The source of the light emission control transistor T5 is connected to the first power signal VLED. The drain of the light emission controlling transistor T5 is electrically connected to the source of the driving transistor T1. The light emission control module 103 may also be formed using a plurality of transistors connected in series.

It should be noted that the driving transistor T1, the data signal writing transistor T2, the first transistor T3, the second transistor T4, and the light emission controlling transistor T5 may be one or more of a low temperature polysilicon thin film transistor, an oxide semiconductor thin film transistor, or an amorphous silicon thin film transistor. Further, the transistors in the light emitting device driving circuit 30 provided in the embodiment of the present application may be set to be the same type of transistors, so as to avoid the influence on the light emitting device driving circuit 30 caused by the difference between different types of transistors.

Referring to fig. 10, fig. 10 is a timing diagram of a third implementation of a light emitting device driving circuit according to an embodiment of the present disclosure. The combination of the first control signal Rb, the second control signal S _ g, the emission control signal EM, and the scan signal scan sequentially corresponds to the initialization stage t1, the threshold voltage detection stage t2, and the threshold voltage compensation stage t 3; that is, within one frame time, the driving control timing of the light emitting device driving circuit 30 provided in the embodiment of the present application includes an initialization phase t1, a threshold voltage detection phase t2, and a threshold voltage compensation phase t 3.

Note that the light emitting device D emits light during the threshold voltage compensation period t 3.

Specifically, in the initialization period t1, the emission control signal EM is at a low potential, the scan signal scan is at a low potential, the first control signal Rb is at a high potential, and the second control signal S _ g is at a high potential.

Specifically, in the threshold voltage detection period t2, the emission control signal EM is at a low level, the scan signal scan is at a high level, the first control signal Rb is at a high level, and the second control signal S _ g is at a high level.

Specifically, in the threshold voltage compensation period t3, the emission control signal EM is at a high level, the scan signal scan is at a high level, the first control signal Rb is at a low level, and the second control signal S _ g is at a low level.

Specifically, the first power signal VLED and the second power signal VSS are both dc voltage sources.

Specifically, referring to fig. 10 and 11, fig. 11 is a schematic diagram of a path of an initialization stage of a light emitting device driving circuit provided in the embodiment of the present application in the driving timing shown in fig. 10.

In the initialization period T1, the first control signal Rb is high, and the first transistor T3 is turned on under the high control of the first control signal Rb, so as to initialize the first transistor T3. For the second control signal S _ g being high, the second transistor T4 is turned on under the high control of the second control signal S _ g to enable initialization of the second transistor T4.

Meanwhile, in the initialization period T1, since the emission control signal EM and the scan signal scan are both low, the first transistor T3 and the emission control transistor T5 are turned off, and thus the driving transistor T1 is turned off.

Specifically, referring to fig. 10 and 12, fig. 12 is a schematic path diagram of a threshold voltage detection stage of a light emitting device driving circuit provided in the embodiment of the present application at the driving timing shown in fig. 10.

In the threshold voltage detecting period T2, the scan signal scan is at a high level, and the data signal writing transistor T2 is turned on under the control of the high level of the scan signal scan, so that the voltage of the data signal data is supplied to the first node P. And since the data signal writing transistor T2 operates in a saturation region of the transistor, the voltage of the first node P is equal to the difference between the voltage of the scan signal scan and the threshold voltage of the data signal writing transistor T2.

Further, the formula for calculating the voltage of the first node P is:

V_p＝V_scan-V_th3wherein V is_pIs the voltage, V, of the first node P during the threshold voltage detection period t2_scanIs the voltage of the scan signal scan at the threshold voltage detection stage t2, V_th3The threshold voltage of the transistor T2 is written for the data signal.

At this time, the first control signal Rb is high, the first transistor T3 is turned on under the high control of the first control signal Rb, and the first detecting unit Sen can detect the voltage of the first node P, so that the threshold voltage of the first transistor T3 can be obtained.

Meanwhile, in the threshold voltage detection period T2, the voltage of the first node P is the difference between the voltage of the scan signal scan and the threshold voltage of the data signal write transistor T2. The scan signal scan is high, so that the voltage of the first node P is also high, and the driving transistor T1 is turned on. And the emission control signal EM is at a low potential, the emission control transistor T5 is turned off under the control of the low potential of the emission control signal EM, and the voltage of the second node Q is equal to the threshold voltage of the driving transistor T1. The second control signal S _ g is at a high level, the second transistor T4 is turned on under the control of the high level of the second control signal S _ g, and the second detection unit S _ d can detect the voltage of the second node Q, so as to obtain the threshold voltage of the driving transistor T1.

Specifically, referring to fig. 10 and 13, fig. 13 is a schematic path diagram of a threshold voltage compensation stage of a light emitting device driving circuit provided in the embodiment of the present application at the driving timing shown in fig. 10.

In the threshold voltage compensation phase T3, the detected threshold voltage of the driving transistor T1 and the detected threshold voltage of the data signal writing transistor T2 are both added to the data signal data to achieve threshold voltage compensation for the data signal writing transistor T2 and the driving transistor T1. Meanwhile, the scan signal scan is high, and the data signal writing transistor T2 is turned on under the control of the high of the scan signal scan, so that the voltage of the data signal data is supplied to the gate of the driving transistor T1. The data signal data is high to turn on the driving transistor T1. At this time, the emission control signal EM is at a high potential, and the transistor T5 is turned on under the high potential control of the emission control signal EM, thereby causing the light emitting device D to emit light.

Referring to fig. 14, fig. 14 is a schematic structural diagram of a backlight module according to an embodiment of the present disclosure. The embodiment of the present application further provides a backlight module 100, which includes a data line 40, a scan line 50, a light-emitting control signal line 60, and the light-emitting device driving circuit 30. The data line 40 is used for providing a data signal. The scan lines 50 are used to provide scan signals. The light emission control signal line 60 is used to supply a light emission control signal. The light emitting device driving circuit 30 is connected to the data lines 40, the scanning lines 50, and the light emission control signal lines 60. The light emitting device driving circuit 30 may refer to the description of the light emitting device driving circuit, and is not described herein again.

Referring to fig. 15, fig. 15 is a schematic structural diagram of a display panel according to an embodiment of the present disclosure. The embodiment of the present application further provides a display panel 200, which includes a plurality of pixel units 2000 arranged in an array, where each pixel unit 2000 includes the light emitting device driving circuit 30, and specific reference may be made to the description of the light emitting device driving circuit 30 above, which is not repeated herein.

The foregoing describes in detail a light emitting device driving circuit, a backlight module and a display panel provided in an embodiment of the present application, and a specific example is applied in the present application to explain the principle and the implementation manner of the present application, and the description of the foregoing embodiment is only used to help understanding the method and the core concept of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.