Pixel driving circuit and driving method thereof, display panel

Abstract

The application discloses a pixel driving circuit, a driving method thereof and a display panel. The pixel driving circuit comprises an analog data writing module, a driving module, a storage module, a light-emitting module, a digital data writing module, a first reference voltage writing module and a digital signal light-emitting control module. The analog data writing module is used for writing analog data into the driving module. The digital data writing module is used for writing digital data into a control end of the digital signal light-emitting control module, and the digital signal light-emitting control module is turned on according to the digital data. The first reference voltage writing module is used for writing a first reference voltage into the control end of the digital signal light-emitting control module, and the digital signal light-emitting control module is turned off according to the first reference voltage. The application achieves a better gray scale development effect, can accurately control the closing of the light-emitting module, makes the light-emitting module better display a to-be-displayed brightness, and improves the display effect of the display panel.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of display, in particular to a pixel driving circuit, a driving method thereof and a display panel. BACKGROUND

[0002] With the development of display technology, display panels are applied more and more widely, and the requirements for display panels are also higher and higher.

[0003] The existing display panel is difficult to expand all gray scales, and the gray scale brightness is prone to sudden change, which affects the display effect of the display panel, and when the pixel driving circuit utilizes digital and analog hybrid driving, it is difficult to accurately control the turn-off of the light-emitting module. SUMMARY

[0004] The present application provides a pixel driving circuit, a driving method thereof and a display panel, to realize better gray scale expansion, improve the display effect of the display panel, and accurately control the turn-off of the light-emitting module when the pixel driving circuit utilizes digital and analog hybrid driving.

[0005] In a first aspect, an embodiment of the present application provides a pixel driving circuit, comprising: an analog data writing module, a driving module, a storage module, a light-emitting module, a digital data writing module, a first reference voltage writing module and a digital signal light-emitting control module.

[0006] The analog data writing module is configured to write analog data to the driving module, the driving module is configured to generate a driving current, the light-emitting module is configured to respond to the driving current, and the storage module is configured to maintain the potential of the control terminal of the driving module.

[0007] The digital data writing module is configured to write digital data to the control terminal of the digital signal light-emitting control module, and the digital signal light-emitting control module is turned on according to the digital data.

[0008] The first reference voltage writing module is configured to write a first reference voltage to the control terminal of the digital signal light-emitting control module, and the digital signal light-emitting control module is turned off according to the first reference voltage.

[0009] Optionally, the digital data writing module comprises a first transistor, and the first reference voltage writing module comprises a second transistor.

[0010] The control terminal of the first transistor is connected to a first scanning signal, the first end of the first transistor is configured to write the digital data, and the second end of the first transistor is electrically connected to the control terminal of the digital signal light-emitting control module.

[0011] The control end of the second transistor is connected to a first control signal, the first end of the second transistor is used for writing the first reference voltage, and the second end of the second transistor is electrically connected to the control end of the digital signal light control module.

[0012] Optionally, the digital data writing module further comprises a third transistor, and the first reference voltage writing module further comprises a fourth transistor.

[0013] The control end of the third transistor is used for connecting to a second scanning signal, the first end of the third transistor is electrically connected to the first end of the first transistor, and the second end of the third transistor is electrically connected to the second end of the first transistor; the first scanning signal is opposite in phase to the second scanning signal, the first transistor is an N-type transistor, and the third transistor is a P-type transistor.

[0014] The control end of the fourth transistor is connected to a second control signal, the first end of the fourth transistor is electrically connected to the first end of the second transistor, and the second end of the fourth transistor is electrically connected to the second end of the second transistor; the first control signal is opposite in phase to the second control signal, the second transistor is a P-type transistor, and the fourth transistor is an N-type transistor.

[0015] Optionally, the pixel driving circuit further comprises a latch module.

[0016] The latch module is used for maintaining the potential of the control end of the digital signal light control module.

[0017] Optionally, the latch module comprises a first inverter and a second inverter, the input end of the first inverter is electrically connected to the control end of the digital signal light control module, the output end of the first inverter is electrically connected to the input end of the second inverter, and the output end of the second inverter is electrically connected to the second end of the first transistor.

[0018] Alternatively, the latch module comprises a first capacitor, the first end of the first capacitor is connected to a first power signal, and the second end of the first capacitor is electrically connected to the control end of the digital signal light control module.

[0019] Optionally, the control end of the analog data writing module is connected to a third scanning signal, the first end of the analog data writing module is used for writing analog data, and the second end of the analog data writing module is electrically connected to the control end of the driving module.

[0020] The first end of the driving module is connected with a first power signal, the second end of the driving module is electrically connected with the first end of the digital signal light emitting control module, the second end of the digital signal light emitting control module is electrically connected with the first end of the light emitting module, and the second end of the light emitting module is connected with a second power signal;

[0021] The first end of the storage module is connected with the first power signal, and the second end of the storage module is electrically connected with the control end of the driving module;

[0022] The first end of the digital data writing module is connected with digital data, and the second end of the digital data writing module is electrically connected with the control end of the digital signal light emitting control module;

[0023] The first end of the first reference voltage writing module is connected with a first reference voltage, and the second end of the first reference voltage writing module is electrically connected with the control end of the digital signal light emitting control module.

[0024] Optionally, the pixel driving circuit further comprises a first initialization module, a second initialization module, a threshold compensation module, a first analog signal light emitting control module and a second analog signal light emitting control module;

[0025] The control end of the first initialization module is connected with a fourth scanning signal, the first end of the first initialization module is connected with a second reference voltage, the second end of the first initialization module is electrically connected with the control end of the driving module, the first end of the storage module is electrically connected with the control end of the driving module, and the second end of the storage module is connected with a first power signal; the first initialization module is used for initializing the driving module;

[0026] The control end of the second initialization module is connected with the fourth scanning signal, the first end of the second initialization module is connected with the second reference voltage, and the second end of the second initialization module is electrically connected with the first end of the light emitting module; the second initialization module is used for initializing the light emitting module;

[0027] The control end of the analog data writing module is connected with a third scanning signal, the first end of the analog data writing module is used for writing analog data, and the second end of the analog data writing module is electrically connected with the first end of the driving module;

[0028] The first end of the driving module is electrically connected with the first end of the first analog signal light emitting control module, and the second end of the driving module is electrically connected with the first end of the second analog signal light emitting control module;

[0029] The control end of the first analog signal light emitting control module is connected with an enable signal, and the second end of the first analog signal light emitting control module is electrically connected with the first power signal;

[0030] The control end of the threshold compensation module is connected to the third scanning signal, the first end of the threshold compensation module is electrically connected to the control end of the driving module, and the second end of the threshold compensation module is electrically connected to the first end of the second analog signal light-emitting control module; the threshold compensation module is used to capture the threshold voltage of the driving module to the control end of the driving module.

[0031] The control end of the second analog signal light-emitting control module is connected to the enable signal, and the second end of the second analog signal light-emitting control module is electrically connected to the digital signal light-emitting control module.

[0032] In a second aspect, the embodiment of the present application further provides a driving method of a pixel driving circuit, used for driving the pixel driving circuit in any of the first aspect, and the driving method of the pixel driving circuit comprises:

[0033] Obtaining a to-be-displayed brightness;

[0034] Determining whether the to-be-displayed brightness meets a preset condition;

[0035] If the to-be-displayed brightness meets the preset condition, determining the analog data according to the to-be-displayed brightness; writing the analog data into the driving module in a data writing stage, and continuously writing the digital data into the digital signal light-emitting control module in a light-emitting stage;

[0036] If the to-be-displayed brightness does not meet the preset condition, determining a first conduction time of the digital data writing module and a second conduction time of the first reference voltage writing module according to the to-be-displayed brightness; writing the analog data into the driving module in the data writing stage, writing the digital data into the control end of the digital light-emitting control module in the first conduction time, and writing the first reference voltage into the control end of the digital light-emitting control module in the second conduction time, wherein the analog data is a fixed value.

[0037] Optionally, the preset condition comprises:

[0038] The to-be-displayed brightness is greater than a preset brightness, or binary data corresponding to the to-be-displayed brightness and binary data corresponding to a current display brightness are opposite to each other in each bit.

[0039] In a third aspect, the embodiment of the present application further provides a display panel, characterized by comprising the pixel driving circuit in any of the first aspect.

[0040] The pixel driving circuit comprises an analog data writing module, a driving module, a storage module, a light-emitting module, a digital data writing module, a first reference voltage writing module and a digital signal light-emitting control module, if the to-be-displayed brightness meets a preset condition, analog data is determined according to the to-be-displayed brightness, the analog data is written into the driving module, the light-emitting module is caused to emit light according to the analog data, and the to-be-displayed brightness is realized, if the to-be-displayed brightness does not meet the preset condition, a first conduction time of the digital data writing module and a second conduction time of the first reference voltage writing module are determined according to the to-be-displayed brightness, and the light-emitting time length of the light-emitting module is controlled by using the first conduction time and the second conduction time, and the to-be-displayed brightness is realized. By using the mixed driving of the analog data and the digital data, the light-emitting module can realize different to-be-displayed brightness, that is, different display gray scales, so that the display gray scale is fully expanded. Moreover, the gray scale jump problem caused by the digital data driving can be avoided by using the analog data driving, the display effect of the display panel is improved, and the uniformity of the display brightness of the display panel is improved. The display gray scale of the display panel is difficult to fully expand, and the display gray scale is prone to jump, the better gray scale expansion effect is achieved, and the light-emitting module can be accurately controlled to be turned off, so that the light-emitting module can better display the to-be-displayed brightness, and the display effect of the display panel is improved. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a circuit structure schematic diagram of a pixel driving circuit provided by an embodiment of the present application;

[0042] Figure 2 is a circuit structure schematic diagram of another pixel driving circuit provided by an embodiment of the present application;

[0043] Figure 3 is a circuit structure schematic diagram of still another pixel driving circuit provided by an embodiment of the present application;

[0044] Figure 4 is a circuit structure schematic diagram of still another pixel driving circuit provided by an embodiment of the present application;

[0045] Figure 5 is a circuit structure schematic diagram of still another pixel driving circuit provided by an embodiment of the present application;

[0046] Figure 6 is a circuit structure schematic diagram of still another pixel driving circuit provided by an embodiment of the present application;

[0047] Figure 7 is a timing diagram of a pixel driving circuit provided by an embodiment of the present application;

[0048] Figure 8 is a timing diagram of another pixel driving circuit provided by an embodiment of the present application;

[0049] Figure 9 is a circuit structure schematic diagram of another pixel driving circuit provided by an embodiment of the present application;

[0050] Figure 10 is a flow chart of a driving method of a pixel driving circuit provided by an embodiment of the present application;

[0051] Figure 11 is a structure schematic diagram of a display panel provided by an embodiment of the present application;

[0052] Figure 12 is a structure schematic diagram of a display device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0053] The present application will be further described below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0054] As mentioned in the background, the existing display panel has the problem that it is difficult to expand all the gray scales, so that the gray scale brightness is prone to sudden change, affecting the display effect of the display panel. The applicant has found through careful research that the cause of this technical problem is that the pixel driving circuit of the existing display panel only uses digital data driving or only uses analog data driving, and the digital data itself has discreteness, which is easy to cause the sudden change of the display gray scale; the expansion range of the voltage and current generated by the analog data is limited, making it difficult to expand all the display gray scales, affecting the display effect of the display panel; and in the existing pixel driving circuit using digital and analog hybrid driving, the current of the light-emitting module is changed by changing the analog data, so as to forcibly turn off the light-emitting module, which is not conducive to the complete turn-off of the light-emitting module, and may cause the light-emitting module to have residual brightness, making it difficult to accurately control the turn-off of the light-emitting module.

[0055] In view of the above technical problems, the present application proposes the following solutions:

[0056] Figure 1 is a circuit structure schematic diagram of a pixel driving circuit provided by an embodiment of the present application, referring to Figure 1The pixel driving circuit comprises an analog data writing module 101, a driving module 102, a storage module 103, a light-emitting module 104, a digital data writing module 105, a first reference voltage writing module 106 and a digital signal light-emitting control module 107; the analog data writing module 101 is used for writing analog data to the driving module 102, the driving module 102 is used for generating a driving current, the light-emitting module 104 is used for responding to the driving current, and the storage module 103 is used for maintaining the potential of the control end of the driving module 102; the digital data writing module 105 is used for writing digital data to the control end of the digital signal light-emitting control module 107, and the digital signal light-emitting control module 107 is turned on according to the digital data; and the first reference voltage writing module 106 is used for writing a first reference voltage to the control end of the digital signal light-emitting control module 107, and the digital signal light-emitting control module 107 is turned off according to the first reference voltage.

[0057] Specifically, the light-emitting module 104 may, for example, be an OLED (Organic Light-Emitting Diode), which is a current-mode device and needs to be driven by a driving current to emit light. The driving module 102 can generate a corresponding driving current according to the analog data written by the analog data writing module 101, and the light-emitting module 104 emits light according to the driving current, thereby realizing the function of analog driving. The digital data writing module 105 writes digital data to the control end of the digital signal light-emitting control module 107, thereby turning on the digital signal light-emitting control module 107. Therefore, the on time of the digital data writing module 105 is controlled, and the on time of the digital signal light-emitting control module 107 is controlled, thereby controlling the light-emitting time of the light-emitting module 104, and realizing the function of digital driving. The first reference voltage writing module 106 writes a first reference voltage to the control end of the digital signal light-emitting control module 107, thereby turning off the digital signal light-emitting control module 107. Therefore, the on time of the first reference voltage writing module 106 is controlled, and the off time of the digital signal light-emitting control module 107 is controlled, thereby controlling the light-emitting time of the light-emitting module 104.

[0058] The pixel driving circuit of the embodiment first judges whether the to-be-displayed brightness meets a preset condition when displaying the to-be-displayed brightness. If the to-be-displayed brightness meets the preset condition, the analog data is determined according to the to-be-displayed brightness, that is, if the preset condition is met, the analog driving is adopted. In the analog driving mode, the analog data is different when the to-be-displayed brightness is different. In the data writing stage, the determined analog data is written into the driving module 102. In the light-emitting stage, the digital data writing module 105 is turned on, the digital data is continuously written into the digital signal light-emitting control module 107, and the light-emitting module 104 continuously emits light according to the analog data, so as to realize the display of the light-emitting module 104 according to the to-be-displayed brightness. If the to-be-displayed brightness does not meet the preset condition, the first turn-on time of the digital data writing module 105 and the second turn-on time of the first reference voltage writing module 106 are determined according to the to-be-displayed brightness, that is, if the preset condition is not met, the digital driving mode is adopted. In the data writing stage, the analog data is written into the driving module 102. In the light-emitting stage, in the first turn-on time, the digital data is continuously written into the digital signal light-emitting control module 107, and the light-emitting module 104 emits light. In the second turn-on time, the first reference voltage is continuously written into the digital signal light-emitting control module 107, and the light-emitting module 104 is turned off, so that the light-emitting module 104 emits light according to the determined first turn-on time and is turned off according to the second turn-on time, thereby realizing the display of the light-emitting module 104 according to the to-be-displayed brightness. When the preset condition is met, the analog data is used to control the current of the light-emitting module 104, so as to achieve the to-be-displayed brightness. When the preset condition is not met, the digital data is used to control the light-emitting time of the light-emitting module 104, so as to achieve the to-be-displayed brightness, thereby realizing different to-be-displayed brightness. Therefore, by using the mixed driving of the analog data and the digital data, the light-emitting module 104 can realize different to-be-displayed brightness, that is, different display gray scales, so as to realize the full expansion of the display gray scale. Moreover, by using the analog data driving, the gray scale jump problem caused by the digital data driving can be avoided, the display effect of the display panel is improved, and the uniformity of the display brightness of the display panel is improved.

[0059] In the digital driving mode, the analog data is a fixed value. Only when the to-be-displayed brightness meets the preset condition, that is, only in the analog driving mode, the analog data is changed according to the to-be-displayed brightness.

[0060] The preset condition may be, for example, display gray scale jump, which may be, for example, that the binary data corresponding to the to-be-displayed brightness and the binary data corresponding to the current display brightness are opposite to each other in each bit. The preset condition may also be that the to-be-displayed brightness is greater than a preset brightness, or other conditions, which can be determined according to actual conditions, and the present embodiment is not limited in this regard.

[0061] In addition, the first reference voltage writing module 106 is used to control the digital signal light emitting control module 107 to be turned off, so that the light emitting module 104 is controlled to be turned off. Since the digital signal light emitting control module 107 is turned off, no current passes through the light emitting module 104, so that the light emitting module 104 is completely turned off and no residual brightness exists, thereby accurately controlling the light emitting module 104 to be turned off. Furthermore, compared with the prior art, the technical solution of the present embodiment is more convenient to change the analog data to forcibly turn off the light emitting module 104. The on time of the first reference voltage writing module 106 is controlled, so that the on time of the digital signal light emitting control module 107 is controlled, thereby controlling the turn-off time of the light emitting module 104, so that the brightness to be displayed is more accurately realized. Generally, the voltage of the digital data does not change, so that the digital signal light emitting control module 107 cannot be turned off by the voltage of the digital data. Furthermore, if the digital data writing module 105 is set to change the digital data to control the digital signal light emitting control module 107 to be turned on and turned off, the digital data writing module 105 needs to be always turned on, and the time of writing the digital data is controlled to realize the brightness to be displayed. However, the writing time of the digital data is difficult to accurately control, and the change of the digital data can cause the gray scale to jump, which is not conducive to the full development of the gray scale. Therefore, the technical solution of the present embodiment sets the digital data writing module 105 and the first reference voltage writing module 106, and controls the first on time of the digital data writing module 105 and the second on time of the first reference voltage writing module 106 to more accurately control the on time and the turn-off time of the digital signal light emitting control module 107, thereby more accurately realizing the brightness to be displayed, which is conducive to the full development of the gray scale. Furthermore, the digital data writing module 105 and the first reference voltage writing module 106 can start to work at different time, and can be in different subframes at the same time, thereby realizing more brightness to be displayed, which is conducive to the full development of the gray scale.

[0062] The pixel driving circuit of the embodiment comprises an analog data writing module, a driving module, a storage module, a light-emitting module, a digital data writing module, a first reference voltage writing module and a digital signal light-emitting control module. If the to-be-displayed brightness meets the preset condition, the analog data is determined according to the to-be-displayed brightness, the analog data is written into the driving module, the light-emitting module emits light according to the analog data, and the to-be-displayed brightness is realized. If the to-be-displayed brightness does not meet the preset condition, the first conduction time of the digital data writing module and the second conduction time of the first reference voltage writing module are determined according to the to-be-displayed brightness, and the light-emitting time of the light-emitting module is controlled by using the first conduction time and the second conduction time, so as to realize the to-be-displayed brightness. The hybrid driving of the analog data and the digital data can make the light-emitting module realize different to-be-displayed brightness, that is, realize different display gray scales, so as to realize the complete expansion of the display gray scale. Moreover, the analog data driving can avoid the gray scale jump problem caused by the digital data driving, improve the display effect of the display panel, and improve the uniformity of the display brightness of the display panel. The technical scheme of the embodiment solves the problems that the display gray scale of the display panel is difficult to completely expand and the display gray scale is prone to jump, achieves better gray scale expansion effect, and can accurately control the closing of the light-emitting module, so that the light-emitting module better displays the to-be-displayed brightness, and the display effect of the display panel is improved.

[0063] On the basis of the above-mentioned embodiment, Figure 2 is another circuit structure schematic diagram of a pixel driving circuit provided by the embodiment of the application. Optionally, referring to Figure 2 The digital data writing module 105 comprises a first transistor T1, and the first reference voltage writing module 106 comprises a second transistor T2. The control end of the first transistor T1 is connected to a first scanning signal Scan1, the first end of the first transistor T1 is used for writing digital data Data1, and the second end of the first transistor T1 is electrically connected to the control end of the digital signal light-emitting control module 107. The control end of the second transistor T2 is connected to a first control signal Clear1, the first end of the second transistor T2 is used for writing a first reference voltage Vref1, and the second end of the second transistor T2 is electrically connected to the control end of the digital signal light-emitting control module 107.

[0064] Specifically, the first scanning signal Scan1 can control the turn-on and turn-off of the first transistor T1, and the turn-on time of the first transistor T1 can be controlled by the first scanning signal Scan1, so as to control the turn-on time of the digital signal light emitting control module 107. The first transistor T1 can be an N-type transistor or a P-type transistor. When the digital data Data1 written into the first transistor T1 is a high level, the first transistor T1 is a P-type transistor, and when the digital data Data1 is a low level, the first transistor T1 is an N-type transistor. Figure 2 In the above embodiment, only the case that the first transistor T1 is an N-type transistor is shown, but it is not limited thereto. The first control signal Clear1 can control the turn-on and turn-off of the second transistor T2, and the turn-on time of the second transistor T2 can be controlled by the first control signal Clear1, so as to control the turn-off time of the digital signal light emitting control module 107. Similarly, the second transistor T2 can be an N-type transistor or a P-type transistor. Figure 2 In the above embodiment, only the case that the second transistor T2 is a P-type transistor is shown, but it is not limited thereto.

[0065] On the basis of the above embodiment, Figure 3 is another circuit structure schematic diagram of a pixel driving circuit provided by the embodiment of the present application. Optionally, referring to Figure 3 The digital data writing module 105 further comprises a third transistor T3, and the first reference voltage writing module 106 further comprises a fourth transistor T4. The control end of the third transistor T3 is used for connecting the second scanning signal Scan2, the first end of the third transistor T3 is electrically connected with the first end of the first transistor T1, and the second end of the third transistor T3 is electrically connected with the second end of the first transistor T1. The first scanning signal Scan1 and the second scanning signal Scan2 are opposite in phase, the first transistor T1 is an N-type transistor, and the third transistor T3 is a P-type transistor. The control end of the fourth transistor T4 is connected with the second control signal Clear2, the first end of the fourth transistor T4 is electrically connected with the first end of the second transistor T2, and the second end of the fourth transistor T4 is electrically connected with the second end of the second transistor T2. The first control signal Clear1 and the second control signal Clear2 are opposite in phase, the second transistor T2 is a P-type transistor, and the fourth transistor T4 is an N-type transistor.

[0066] Specifically, the first transistor T1 is set as an N-type transistor and the third transistor T3 is set as a P-type transistor, so that the digital data Data1 can be effectively transmitted regardless of whether it is at a low level or a high level, thereby improving the driving efficiency of the pixel driving circuit. The first scanning signal Scan1 and the second scanning signal Scan2 are opposite in phase, so that the first transistor T1 and the third transistor T3 can be turned on at the same time, and the digital data Data1 can be written into the digital signal light-emitting control module 107. The third transistor T3 is set as a P-type transistor and the fourth transistor T4 is set as an N-type transistor, so that the first reference voltage Vref1 can be effectively transmitted regardless of whether it is at a low level or a high level, thereby improving the driving efficiency of the pixel driving circuit. The first control signal Clear1 and the second control signal Clear2 are opposite in phase, so that the second transistor T2 and the fourth transistor T4 can be turned on at the same time, and the first reference voltage Vref1 can be written into the digital signal light-emitting control module 107.

[0067] Optionally, continuing to refer to Figure 2 , the pixel driving circuit further comprises a latch module 108; the latch module 108 is configured to maintain the potential of the control end of the digital signal light-emitting control module 107.

[0068] Specifically, the latch module 108 has the function of data storage, and can maintain the potential of the control end of the digital signal light-emitting control module 107, so that the potential of the control end of the digital signal light-emitting control module 107 is not affected by the environment. Only when the digital data written by the digital data writing module 105 changes, the potential of the control end of the digital signal light-emitting control module 107 will change, thereby ensuring the accuracy of digital data writing.

[0069] Optionally, continuing to refer to Figure 2 , the latch module 108 comprises a first inverter 108a and a second inverter 108b, the input end of the first inverter 108a is electrically connected with the control end of the digital signal light-emitting control module 107, the output end of the first inverter 108a is electrically connected with the input end of the second inverter 108b, and the output end of the second inverter 108b is electrically connected with the second end of the first transistor T1.

[0070] Alternatively, Figure 4 is another circuit structure schematic diagram of a pixel driving circuit provided by the embodiment of the present application. Optionally, referring to Figure 4 , the latch module 108 comprises a first capacitor C1, the first end of the first capacitor C1 is connected to a first power supply signal, and the second end of the first capacitor C1 is electrically connected with the control end of the digital signal light-emitting control module 107.

[0071] Specifically, the latch module 108 can include a first inverter 108a and a second inverter 108b, which can realize the latching and isolation of the signal, ensure that the potential of the control end of the digital signal light emitting control module 107 will not be affected by the environment, thereby maintaining the potential of the control end of the digital signal light emitting control module 107, ensuring the accuracy of digital data writing. In addition, the first inverter 108a and the second inverter 108b also have the effect of data shaping.

[0072] Alternatively, the latch module 108 can include a first capacitor C1, which has the effect of storing energy, thereby maintaining the potential of the control end of the digital signal light emitting control module 107, and the cost of the capacitor is low, which can reduce the cost of the pixel driving circuit.

[0073] Optionally, continuing to refer to Figure 1 , the control end of the analog data writing module 101 is connected to the third scanning signal Scan3, the first end of the analog data writing module 101 is used for writing analog data Data2, the second end of the analog data writing module 101 is electrically connected with the control end of the driving module 102; the first end of the driving module 102 is used for connecting the first power signal, the second end of the driving module 102 is electrically connected with the first end of the digital signal light emitting control module 107, the second end of the digital signal light emitting control module 107 is electrically connected with the first end of the light emitting module 104, and the second end of the light emitting module 104 is connected with the second power signal; the first end of the storage module 103 is connected with the first power signal, and the second end of the storage module 103 is electrically connected with the control end of the driving module 102; the first end of the digital data writing module 105 is connected with the digital data Data1, and the second end of the digital data writing module 105 is electrically connected with the control end of the digital signal light emitting control module 107; the first end of the first reference voltage writing module 106 is connected with the first reference voltage Vref1, and the second end of the first reference voltage writing module 106 is electrically connected with the control end of the digital signal light emitting control module 107.

[0074] Specifically, the analog data writing module 101 is controlled to be turned on or turned off by the third scanning signal Scan3. When the analog data writing module 101 is turned on, the analog data Data2 is written into the driving module 102, and the driving module 102 generates a corresponding driving current. When the digital data writing module 105 is turned on, the digital data Data1 is written into the digital signal light emitting control module 107, so that the digital signal light emitting control module 107 is turned on, and the light emitting module 104 can emit light according to the driving current. When the first reference voltage writing module 106 is turned on, the first reference voltage Vref1 is written into the digital signal light emitting control module 107, so that the digital signal light emitting control module 107 is turned off, and the light emitting module 104 cannot obtain the driving current and is turned off. Therefore, by controlling the first turn-on time of the digital data writing module 105 and the second turn-on time of the first reference voltage writing module 106, the turn-on time and the turn-off time of the digital signal light emitting control module 107 can be controlled, so that the light emitting time of the light emitting module 104 can be controlled.

[0075] On the basis of the technical solutions in the above aspect, Figure 5 is another circuit structure schematic diagram of a pixel driving circuit provided by an embodiment of the present application. Optionally, referring to Figure 5 , the analog data writing module 101 comprises a fifth transistor T5, the driving module 102 comprises a sixth transistor T6, the storage module 103 comprises a second capacitor C2, and the light emitting module 104 comprises an organic light emitting diode D1. The control end of the fifth transistor T5 is the control end of the analog data writing module 101, the first end of the fifth transistor T5 is the first end of the analog data writing module 101, and the second end of the fifth transistor T5 is the second end of the analog data writing module 101. The control end of the sixth transistor T6 is the control end of the driving module 102, the first end of the sixth transistor T6 is the first end of the driving module 102, and the second end of the sixth transistor T6 is the second end of the driving module 102. The first end of the second capacitor C2 is the first end of the storage module 103, and the second end of the second capacitor C2 is the second end of the storage module 103. The anode of the organic light emitting diode D1 is the first end of the light emitting module 104, and the cathode of the organic light emitting diode D1 is the second end of the light emitting module 104. The first power supply signal is a voltage VDD, and the second power supply signal is a voltage VSS. The digital signal light emitting control module 107 comprises a seventh transistor T7, the control end of the seventh transistor T7 is the control end of the digital signal light emitting control module 107, the first end of the seventh transistor T7 is the first end of the digital signal light emitting control module 107, and the second end of the seventh transistor T7 is the second end of the digital signal light emitting control module 107. Figure 5 In the above aspect, only the case that the digital data writing module 105 comprises the first transistor T1 and the third transistor T3, and the first reference voltage writing module 106 comprises the second transistor T2 and the fourth transistor T4 is shown, but the present application is not limited thereto.

[0076] Figure 6 is another circuit structure schematic diagram of the pixel driving circuit provided by the embodiment of the present application, and optionally, referring to Figure 6 The pixel driving circuit further includes a first initialization module 109, a second initialization module 110, a threshold compensation module 111, a first analog signal light emitting control module 112, and a second analog signal light emitting control module 113. The control end of the first initialization module 109 is connected to the fourth scan signal Scan4, the first end of the first initialization module 109 is connected to the second reference voltage Vref2, the second end of the first initialization module 109 is electrically connected to the control end of the driving module 102, the first end of the storage module 103 is electrically connected to the control end of the driving module 102, and the second end of the storage module 103 is connected to the first power signal. The first initialization module 109 is used to initialize the driving module 102. The control end of the second initialization module 110 is connected to the fourth scan signal Scan4, the first end of the second initialization module 110 is connected to the second reference voltage Vref2, and the second end of the second initialization module 110 is electrically connected to the first end of the light emitting module 104. The second initialization module 110 is used to initialize the light emitting module 104. The control end of the analog data writing module 101 is connected to the third scan signal Scan3, the first end of the analog data writing module 101 is used to write the analog data Data2, and the second end of the analog data writing module 101 is electrically connected to the first end of the driving module 102. The first end of the driving module 102 is electrically connected to the first end of the first analog signal light emitting control module 112, and the second end of the driving module 102 is electrically connected to the first end of the second analog signal light emitting control module 113. The control end of the first analog signal light emitting control module 112 is connected to the enable signal EM, and the second end of the first analog signal light emitting control module 112 is electrically connected to the first power signal. The control end of the threshold compensation module 111 is connected to the third scan signal Scan3, the first end of the threshold compensation module 111 is electrically connected to the control end of the driving module 102, and the second end of the threshold compensation module 111 is electrically connected to the first end of the second analog signal light emitting control module 113. The threshold compensation module 111 is used to capture the threshold voltage of the driving module 102 to the control end of the driving module 102. The control end of the second analog signal light emitting control module 113 is connected to the enable signal EM, and the second end of the second analog signal light emitting control module 113 is electrically connected to the digital signal light emitting control module 107.

[0077] Specifically, Figure 7 is a timing diagram of the pixel driving circuit provided by the embodiment of the present application, and referring to Figure 7In the initialization stage t1, the fourth scan signal Scan4 is low, the fourth scan signal Scan4 controls the first initialization module 109 and the second initialization module 110 to be turned on, so that the second reference voltage Vref2 is written into the first initialization module 109 and the second initialization module 110, thereby initializing the driving module 102 and the light emitting module 104. In the analog data writing and threshold compensation stage t2, the third scan signal Scan3 is low, the third scan signal Scan3 controls the analog data writing module 101 to be turned on, so that the analog data Data2 is written into the driving module 102 through the analog data writing module 101, and at the same time, the threshold compensation module 111 is turned on to perform threshold compensation, so that the current flowing through the light emitting module 104 is independent of the threshold voltage of the driving module 102. In the light emitting stage t3, the enable signal EM is low, thereby controlling the first analog signal light emitting control module 112 and the second analog signal light emitting control module 113 to be turned on, and the first scan signal Scan1 controls the digital data writing module 105 to be turned on, so that the digital data Data1 is written into the digital signal light emitting control module 107, thereby making the digital signal light emitting control module 107 also turned on, so that the light emitting module 104 is turned on, and the light emitting module 104 emits light. Figure 8 is another timing diagram of a pixel driving circuit provided by the embodiment of the present application, referring to Figure 8 , Figure 8 In the horizontal coordinate of the timing diagram, the time is represented, and in the vertical coordinate, the number of pixel rows is represented, Figure 8 In the timing diagram, only the case that the number of rows is 16 is shown, but it is not limited, Figure 8The solid line in the figure represents the first scanning signal Scan1, the dashed line represents the first control signal Clear1, SF1, SF2, SF3 and SF4 represent scanning time periods corresponding to different display luminance, thus, in the light emitting stage, the scanning time of the first scanning signal Scan1 and the scanning time of the first control signal Clear1 can be determined according to the display luminance, so as to control the first on time of the digital data writing module 105 and the second on time of the first reference voltage writing module 106, thus controlling the on time and the off time of the digital signal light emitting control module 107, so as to control the light emitting module 104 to emit light according to the display luminance, so as to realize different display gray scales. However, when the current display luminance and the display luminance are large, it is not easy to control the on time and the off time of the digital signal light emitting control module 107 to control the light emitting module 104 to display the display luminance, at this time, the analog data Data2 can be adjusted according to the display luminance, so as to control the current of the light emitting module 104, so as to make the light emitting module 104 display the display luminance. Moreover, the scanning time of the first scanning signal Scan1 is binary data, when the binary data corresponding to the display luminance and the binary data corresponding to the current display luminance are opposite to each other in each bit, the display gray scale of the light emitting module 104 is easy to jump, at this time, the analog data Data2 can be adjusted according to the display luminance, so as to control the current of the light emitting module 104, so as to make the light emitting module 104 display the display luminance. Therefore, through the mixed driving of the digital data and the analog data, the display gray scale can be better expanded, different display gray scales can be better realized, the gray scale jump problem caused by the digital data driving can be avoided, the display effect of the display panel is improved, and the uniformity of the display luminance of the display panel is improved.

[0078] Figure 9 is another circuit structure schematic diagram of a pixel driving circuit provided by the embodiment of the present application, optionally, referring to Figure 9The first initialization module 109 comprises an eighth transistor T8, a control end of the eighth transistor T8 is a control end of the first initialization module 109, a first end of the eighth transistor T8 is a first end of the first initialization module 109, and a second end of the eighth transistor T8 is a second end of the first initialization module 109. The second initialization module 110 comprises a ninth transistor T9, a control end of the ninth transistor T9 is a control end of the second initialization module 110, a first end of the ninth transistor T9 is a first end of the second initialization module 110, and a second end of the ninth transistor T9 is a second end of the second initialization module 110. The threshold compensation module 111 comprises a tenth transistor T10, a control end of the tenth transistor T10 is a control end of the threshold compensation module 111, a first end of the tenth transistor T10 is a first end of the threshold compensation module 111, and a second end of the tenth transistor T10 is a second end of the threshold compensation module 111. The first analog signal light-emitting control module 112 comprises an eleventh transistor T11, a control end of the eleventh transistor T11 is a control end of the first analog signal light-emitting control module 112, a first end of the eleventh transistor T11 is a first end of the first analog signal light-emitting control module 112, and a second end of the eleventh transistor T11 is a second end of the first analog signal light-emitting control module 112. The second analog signal light-emitting control module 113 comprises a twelfth transistor T12, a control end of the twelfth transistor T12 is a control end of the second analog signal light-emitting control module 113, a first end of the twelfth transistor T12 is a first end of the second analog signal light-emitting control module 113, and a second end of the twelfth transistor T12 is a second end of the second analog signal light-emitting control module 113.

[0079] The embodiment further provides a driving method of the pixel driving circuit. Figure 10 is a flowchart of the driving method of the pixel driving circuit provided by the embodiment of the application, and Figure 10 The driving method of the pixel driving circuit comprises the following steps.

[0080] In S101, the brightness to be displayed is acquired.

[0081] In S102, it is judged whether the brightness to be displayed meets a preset condition; if yes, S103 is executed, and if not, S104 is executed.

[0082] In S103, analog data is determined according to the brightness to be displayed; the analog data is written into the driving module in a data writing stage, and the digital data is continuously written into the digital signal light-emitting control module in a light-emitting stage.

[0083] S104, determining the first on time of the digital data writing module and the second on time of the first reference voltage writing module according to the to-be-displayed brightness; writing analog data to the driving module in a data writing stage, writing digital data to the control end of the digital light emitting control module in the first on time, and writing the first reference voltage to the control end of the digital light emitting control module in the second on time, wherein the analog data is a fixed value.

[0084] The specific working process of the driving method of the embodiment can refer to the description of the pixel driving circuit part of the embodiment of the application, which will not be repeated here. By using the mixed driving of analog data and digital data, the light emitting module can realize different to-be-displayed brightness, that is, different display gray scales, so as to realize the full expansion of the display gray scale. Moreover, by using the analog data driving, the gray scale jump problem caused by the digital data driving can be avoided, the display effect of the display panel is improved, and the uniformity of the display brightness of the display panel is improved.

[0085] Optionally, the preset condition includes that the to-be-displayed brightness is greater than a preset brightness, or the binary data corresponding to the to-be-displayed brightness and the binary data corresponding to the current display brightness are opposite to each other in each bit.

[0086] Figure 11 is a structural schematic diagram of a display panel provided by an embodiment of the application, referring to Figure 11 The display panel includes a plurality of pixel driving circuits PX provided by any embodiment of the application, and the display panel can include a plurality of scanning lines (S1-Sk) and data lines (DL1-DLj) which are interlaced, the pixel driving circuit is located in an area defined by the scanning line and the data line, and the scanning line can include a first scanning line, a second scanning line and a third scanning line, for example, to provide a scanning signal for the pixel driving circuit PX. Since it includes the pixel driving circuit provided by any embodiment of the application, it also has the same beneficial effects, which will not be repeated here.

[0087] Figure 12 is a structural schematic diagram of a display device provided by an embodiment of the application, referring to Figure 12 The display device includes the display panel provided by any embodiment of the application, and the display device can be a mobile phone, a tablet, a display, a smart watch, an MP3, an MP4 or other wearable devices, etc. Since it includes the display panel provided by any embodiment of the application, it also has the same beneficial effects, which will not be repeated here.

[0088] Note that the above merely describes preferred embodiments of the present application and the principles of the technology applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, modifications and substitutions can be made without departing from the scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the claims.

Claims

1. A pixel driving circuit, characterized in that, The application relates to a pixel driving circuit. The pixel driving circuit comprises an analog data writing module, a driving module, a storage module, a light-emitting module, a digital data writing module, a first reference voltage writing module and a digital signal light-emitting control module. The analog data writing module is used for writing analog data into the driving module, the driving module is used for generating a driving current, the light-emitting module is used for responding to the driving current, and the storage module is used for maintaining the potential of the control end of the driving module. The digital data writing module is used for writing digital data into the control end of the digital signal light-emitting control module, and the digital signal light-emitting control module is turned on according to the digital data. The first reference voltage writing module is used for writing a first reference voltage into the control end of the digital signal light-emitting control module, and the digital signal light-emitting control module is turned off according to the first reference voltage. The pixel driving circuit judges whether the to-be-displayed brightness meets a preset condition when displaying the to-be-displayed brightness. If the to-be-displayed brightness meets the preset condition, analog data is determined according to the to-be-displayed brightness, the analog data is written into the driving module, the light-emitting module emits light according to the analog data, and the to-be-displayed brightness is realized. If the to-be-displayed brightness does not meet the preset condition, the first turn-on time of the digital data writing module and the second turn-on time of the first reference voltage writing module are determined according to the to-be-displayed brightness, the light-emitting time of the light-emitting module is controlled by using the first turn-on time and the second turn-on time, and the to-be-displayed brightness is realized. The preset condition comprises that the to-be-displayed brightness is greater than a preset brightness, or the binary data corresponding to the to-be-displayed brightness and the binary data corresponding to the current display brightness are opposite to each other in each bit. The digital data writing module comprises a first transistor, and the first reference voltage writing module comprises a second transistor.

2. The pixel driving circuit according to claim 1, characterized in that, The control end of the first transistor is connected to a first scanning signal, the first end of the first transistor is used for writing the digital data, and the second end of the first transistor is electrically connected to the control end of the digital signal light-emitting control module. The control end of the second transistor is connected to a first control signal, the first end of the second transistor is used for writing the first reference voltage, and the second end of the second transistor is electrically connected to the control end of the digital signal light-emitting control module. The digital data writing module further comprises a third transistor, and the first reference voltage writing module further comprises a fourth transistor.

3. The pixel driving circuit of claim 2, wherein, The control end of the third transistor is used for connecting to a second scanning signal, the first end of the third transistor is electrically connected to the first end of the first transistor, and the second end of the third transistor is electrically connected to the second end of the first transistor; the first scanning signal and the second scanning signal are opposite in phase, the first transistor is an N-type transistor, and the third transistor is a P-type transistor. The control end of the fourth transistor is connected to a second control signal, the first end of the fourth transistor is electrically connected to the first end of the second transistor, and the second end of the fourth transistor is electrically connected to the second end of the second transistor; the first control signal and the second control signal are opposite in phase, the second transistor is a P-type transistor, and the fourth transistor is an N-type transistor. ​ 4. The pixel driving circuit of claim 2, wherein, The latch module is further used for maintaining the potential of the control end of the digital signal light-emitting control module.

5. The pixel driving circuit of claim 4, wherein the latch module comprises a first inverter and a second inverter, an input end of the first inverter is electrically connected to the control end of the digital signal light-emitting control module, an output end of the first inverter is electrically connected to an input end of the second inverter, and an output end of the second inverter is electrically connected to the second end of the first transistor. Alternatively, the latch module comprises a first capacitor, a first end of the first capacitor is connected to a first power supply signal, and a second end of the first capacitor is electrically connected to the control end of the digital signal light-emitting control module. A control end of the analog data writing module is connected to a third scan signal, a first end of the analog data writing module is used for writing analog data, and a second end of the analog data writing module is electrically connected to a control end of the driving module. A first end of the driving module is used for connecting the first power supply signal, a second end of the driving module is electrically connected to a first end of the digital signal light-emitting control module, a second end of the digital signal light-emitting control module is electrically connected to a first end of the light-emitting module, and a second end of the light-emitting module is connected to a second power supply signal.

6. The pixel driving circuit of claim 1, wherein, A first end of the storage module is connected to the first power supply signal, and a second end of the storage module is electrically connected to a control end of the driving module. A first end of the digital data writing module is connected to digital data, and a second end of the digital data writing module is electrically connected to a control end of the digital signal light-emitting control module. A first end of the first reference voltage writing module is connected to a first reference voltage, and a second end of the first reference voltage writing module is electrically connected to a control end of the digital signal light-emitting control module. The pixel driving circuit further comprises a first initialization module, a second initialization module, a threshold compensation module, a first analog signal light-emitting control module and a second analog signal light-emitting control module. A control end of the first initialization module is connected to a fourth scan signal, a first end of the first initialization module is connected to a second reference voltage, a second end of the first initialization module is electrically connected to a control end of the driving module, a first end of the storage module is electrically connected to the control end of the driving module, and a second end of the storage module is connected to a first power supply signal.

7. The pixel driving circuit according to any one of claims 1-6, wherein, The first initialization module is used for initializing the driving module. A control end of the second initialization module is connected to the fourth scan signal, a first end of the second initialization module is connected to the second reference voltage, and a second end of the second initialization module is electrically connected to a first end of the light-emitting module. The second initialization module is used for initializing the light-emitting module. A control end of the analog data writing module is connected to a third scan signal, a first end of the analog data writing module is used for writing analog data, and a second end of the analog data writing module is electrically connected to a first end of the driving module. ​ The first end of the driving module is electrically connected with the first end of the first analog signal light-emitting control module, and the second end of the driving module is electrically connected with the first end of the second analog signal light-emitting control module. The control end of the first analog signal light-emitting control module is connected with an enable signal, and the second end of the first analog signal light-emitting control module is electrically connected with the first power signal. The control end of the threshold compensation module is connected with the third scanning signal, the first end of the threshold compensation module is electrically connected with the control end of the driving module, and the second end of the threshold compensation module is electrically connected with the first end of the second analog signal light-emitting control module; the threshold compensation module is used for capturing the threshold voltage of the driving module to the control end of the driving module. The control end of the second analog signal light-emitting control module is connected with the enable signal, and the second end of the second analog signal light-emitting control module is electrically connected with the digital signal light-emitting control module.

8. A driving method of a pixel driving circuit, for driving the pixel driving circuit according to any one of claims 1 to 7, characterized by, The driving method of the pixel driving circuit comprises: acquiring a to-be-displayed brightness; determining whether the to-be-displayed brightness meets a preset condition; if the to-be-displayed brightness meets the preset condition, determining the analog data according to the to-be-displayed brightness, writing the analog data into the driving module in a data writing stage, and continuously writing the digital data into the digital signal light-emitting control module in a light-emitting stage; if the to-be-displayed brightness does not meet the preset condition, determining a first conduction time of the digital data writing module and a second conduction time of the first reference voltage writing module according to the to-be-displayed brightness, writing the analog data into the driving module in the data writing stage, writing the digital data into the control end of the digital signal light-emitting control module in the first conduction time, and writing the first reference voltage into the control end of the digital signal light-emitting control module in the second conduction time, wherein the analog data is a fixed value.

9. The driving method according to claim 8, wherein The preset condition comprises: the to-be-displayed brightness is greater than a preset brightness, or binary data corresponding to the to-be-displayed brightness and binary data corresponding to a current display brightness are all opposite to each other in each bit.

10. A display panel, characterized by, The pixel driving circuit comprises any one of claims 1-7. The pixel driving circuit comprises any one of claims 1-7.

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